Sample records for core model fluid
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NASA Technical Reports Server (NTRS)
Benton, E. R. (Principal Investigator)
1982-01-01
MAGSAT data were used to construct a variety of spherical harmonic models of the main geomagnetic field emanating from Earth's liquid core at poch 1980. These models were used to: (1) accurately determine the radius of Earth's core by a magnetic method, (2) calculate estimates, of the long-term ange of variation of geomagnetic Gauss coefficients; (3) establish a preferred truncation level for current spherical harmonic models of the main geomagnetic field from the core; (4) evaluate a method for taking account of electrical conduction in the mantle when the magnetic field is downward continued to the core-mantle boundary; and (5) establish that upwelling and downwelling of fluid motion at the top of the core is probably detectable, observationally. A fluid dynamics forecast model was not produced because of insufficient data.
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Stevenson, D J
1981-11-06
Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with the following properties. Core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and laboratory data.
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Modeling Hydrothermal Activity on Enceladus
NASA Astrophysics Data System (ADS)
Stamper, T., Jr.; Farough, A.
2017-12-01
Cassini's mass spectrometer data and gravitational field measurements imply water-rock interactions around the porous core of Enceladus. Using such data we characterize global heat and fluid transport properties of the core and model the ongoing hydrothermal activity on Enceladus. We assume that within the global ocean beneath the surface ice, seawater percolates downward into the core where it is heated and rises to the oceanfloor where it emanates in the form of diffuse discharge. We utilize the data from Hsu et al., [2015] with models of diffuse flow in seafloor hydrothermal systems by Lowell et al., [2015] to characterize the global heat transport properties of the Enceladus's core. Based on direct observations the gravitational acceleration (g) is calculated 0.123 m s-2. We assume fluid's density (ρ) is 103 kg m-3 and the specific heat of the fluid (cf) is 4000 Jkg-1 °C-1. From these values effective thermal diffusivity (a*) is calculated as 10-6 m2 s-1. We also assume the coefficient of thermal expansion of fluid (αf) and the kinematic viscosity of fluid (ν) to be 10-4 °C-1 and 10-6 m2 s-1 respectively. The estimated Rayleigh number (Ra) ranges between 0.11-2468.0, for core porosity (φ) of 5-15%, permeability (k) between 10-12-10-8 m2 and temperature between 90-200 °C and the depth of fluid circulation of 100 m. High values of Rayleigh number, cause vigorous convection within the core of Enceladus. Numerical modeling of reactive transport in multicomponent, multiphase systems is required to obtain a full understanding of the characteristics and evolution of the hydrothermal system on Enceladus, but simple scaling laws can provide insight into the physics of water-rock interactions.
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NASA Astrophysics Data System (ADS)
Seyed-Mahmoud, B.; Moradi, A.; Kamruzzaman, M.; Naseri, H.
2015-08-01
The Earth's outer core is a rotating ellipsoidal shell of compressible, stratified and self-gravitating fluid. As such, in the treatment of geophysical problems a realistic model of this body needs to be considered. In this work, we consider compressible and stratified fluid core models with different stratification parameters, related to the local Brunt-Väisälä frequency, in order to study the effects of the core's density stratification on the frequencies of some of the inertial-gravity modes of this body. The inertial-gravity modes of the core are free oscillations with periods longer than 12 hr. Historically, an incompressible and homogeneous fluid is considered to study these modes and analytical solutions are known for the frequencies and the displacement eigenfunctions of a spherical model. We show that for a compressible and stratified spherical core model the effects of non-neutral density stratification may be significant, and the frequencies of these modes may change from model to model. For example, for a spherical core model the frequency of the spin-over mode, the (2, 1, 1) mode, is unaffected while that of the (4, 1, 1) mode is changed from -0.410 for the Poincaré core model to -0.434, -0.447 and -0.483 for core models with the stability parameter β = -0.001, -0.002 and -0.005, respectively, a maximum change of about 18 per cent when β = -0.005. Our results also show that for small stratification parameter, |β| ≤ 0.005, the frequency of an inertial-gravity mode is a nearly linear function of β but the slope of the line is different for different modes, and that the effects of density stratification on the frequency of a mode is likely related to its spatial structure, which remains the same in different Earth models. We also compute the frequencies of some of the modes of the `PREM' (spherical shell) core model and show that the frequencies of these modes may also be significantly affected by non-zero β.
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NASA Technical Reports Server (NTRS)
Stevenson, D. J.
1981-01-01
Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with five basic properties. These are that core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and labroatory data.
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Computer Simulation To Assess The Feasibility Of Coring Magma
NASA Astrophysics Data System (ADS)
Su, J.; Eichelberger, J. C.
2017-12-01
Lava lakes on Kilauea Volcano, Hawaii have been successfully cored many times, often with nearly complete recovery and at temperatures exceeding 1100oC. Water exiting nozzles on the diamond core bit face quenches melt to glass just ahead of the advancing bit. The bit readily cuts a clean annulus and the core, fully quenched lava, passes smoothly into the core barrel. The core remains intact after recovery, even when there are comparable amounts of glass and crystals with different coefficients of thermal expansion. The unique resulting data reveal the rate and sequence of crystal growth in cooling basaltic lava and the continuous liquid line of descent as a function of temperature from basalt to rhyolite. Now that magma bodies, rather than lava pooled at the surface, have been penetrated by geothermal drilling, the question arises as to whether similar coring could be conducted at depth, providing fundamentally new insights into behavior of magma. This situation is considerably more complex because the coring would be conducted at depths exceeding 2 km and drilling fluid pressures of 20 MPa or more. Criteria that must be satisfied include: 1) melt is quenched ahead of the bit and the core itself must be quenched before it enters the barrel; 2) circulating drilling fluid must keep the temperature of the coring assembling cooled to within operational limits; 3) the drilling fluid column must nowhere exceed the local boiling point. A fluid flow simulation was conducted to estimate the process parameters necessary to maintain workable temperatures during the coring operation. SolidWorks Flow Simulation was used to estimate the effect of process parameters on the temperature distribution of the magma immediately surrounding the borehole and of drilling fluid within the bottom-hole assembly (BHA). A solid model of the BHA was created in SolidWorks to capture the flow behavior around the BHA components. Process parameters used in the model include the fluid properties and temperature of magma, coolant flow rate, rotation speed, and rate of penetration (ROP). The modeling results indicate that there are combinations of process parameters that will provide sufficient cooling to enable the desired coring process in magma.
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Steady induction effects in geomagnetism. Part 1A: Steady motional induction of geomagnetic chaos
NASA Technical Reports Server (NTRS)
Voorhies, Coerte V.
1992-01-01
Geomagnetic effects of magnetic induction by hypothetically steady fluid motion and steady magnetic flux diffusion near the top of Earth's core are investigated using electromagnetic theory, simple magnetic earth models, and numerical experiments with geomagnetic field models. The problem of estimating a steady fluid velocity field near the top of Earth's core which induces the secular variation indicated by broad-scale models of the observed geomagnetic field is examined and solved. In Part 1, the steady surficial core flow estimation problem is solved in the context of the source-free mantle/frozen-flux core model. In the first paper (IA), the theory underlying such estimates is reviewed and some consequences of various kinematic and dynamic flow hypotheses are derived. For a frozen-flux core, fluid downwelling is required to change the mean square normal magnetic flux density averaged over the core-mantle boundary. For surficially geostrophic flow, downwelling implies poleward flow. The solution of the forward steady motional induction problem at the surface of a frozen-flux core is derived and found to be a fine, easily visualized example of deterministic chaos. Geomagnetic effects of statistically steady core surface flow may well dominate secular variation over several decades. Indeed, effects of persistent, if not steady, surficially geostrophic core flow are described which may help explain certain features of the present broad-scale geomagnetic field and perhaps paleomagnetic secular variation.
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Modeling the Conducting Stably-Stratified Layer of the Earth's Core
NASA Astrophysics Data System (ADS)
Petitdemange, L.; Philidet, J.; Gissinger, C.
2017-12-01
Observations of the Earth magnetic field as well as recent theoretical works tend to show that the Earth's outer liquid core is mostly comprised of a convective zone in which the Earth's magnetic field is generated - likely by dynamo action -, but also features a thin, stably stratified layer at the top of the core.We carry out direct numerical simulations by modeling this thin layer as an axisymmetric spherical Couette flow for a stably stratified fluid embedded in a dipolar magnetic field. The dynamo region is modeled by a conducting inner core rotating slightly faster than the insulating mantle due to magnetic torques acting on it, such that a weak differential rotation (low Rossby limit) can develop in the stably stratified layer.In the case of a non-stratified fluid, the combined action of the differential rotation and the magnetic field leads to the well known regime of `super-rotation', in which the fluid rotates faster than the inner core. Whereas in the classical case, this super-rotation is known to vanish in the magnetostrophic limit, we show here that the fluid stratification significantly extends the magnitude of the super-rotation, keeping this phenomenon relevant for the Earth core. Finally, we study how the shear layers generated by this new state might give birth to magnetohydrodynamic instabilities or waves impacting the secular variations or jerks of the Earth's magnetic field.
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Some anticipated contributions to core fluid dynamics from the GRM
NASA Technical Reports Server (NTRS)
Vanvorhies, C.
1985-01-01
It is broadly maintained that the secular variation (SV) of the large scale geomagnetic field contains information on the fluid dynamics of Earth's electrically conducting outer core. The electromagnetic theory appropriate to a simple Earth model has recently been combined with reduced geomagnetic data in order to extract some of this information and ascertain its significance. The simple Earth model consists of a rigid, electrically insulating mantle surrounding a spherical, inviscid, and perfectly conducting liquid outer core. This model was tested against seismology by using truncated spherical harmonic models of the observed geomagnetic field to locate Earth's core-mantle boundary, CMB. Further electromagnetic theory has been developed and applied to the problem of estimating the horizontal fluid motion just beneath CMB. Of particular geophysical interest are the hypotheses that these motions: (1) include appreciable surface divergence indicative of vertical motion at depth, and (2) are steady for time intervals of a decade or more. In addition to the extended testing of the basic Earth model, the proposed GRM provides a unique opportunity to test these dynamical hypotheses.
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Evaluation of HFIR LEU Fuel Using the COMSOL Multiphysics Platform
DOE Office of Scientific and Technical Information (OSTI.GOV)
Primm, Trent; Ruggles, Arthur; Freels, James D
2009-03-01
A finite element computational approach to simulation of the High Flux Isotope Reactor (HFIR) Core Thermal-Fluid behavior is developed. These models were developed to facilitate design of a low enriched core for the HFIR, which will have different axial and radial flux profiles from the current HEU core and thus will require fuel and poison load optimization. This report outlines a stepwise implementation of this modeling approach using the commercial finite element code, COMSOL, with initial assessment of fuel, poison and clad conduction modeling capability, followed by assessment of mating of the fuel conduction models to a one dimensional fluidmore » model typical of legacy simulation techniques for the HFIR core. The model is then extended to fully couple 2-dimensional conduction in the fuel to a 2-dimensional thermo-fluid model of the coolant for a HFIR core cooling sub-channel with additional assessment of simulation outcomes. Finally, 3-dimensional simulations of a fuel plate and cooling channel are presented.« less
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The Coupling between Earth's Inertial and Rotational Eigenmodes
NASA Astrophysics Data System (ADS)
Triana, S. A.; Rekier, J.; Trinh, A.; Laguerre, R.; Zhu, P.; Dehant, V. M. A.
2017-12-01
Wave motions in the Earth's fluid core, supported by the restoring action of both buoyancy (within the stably stratified top layer) and the Coriolis force, lead to the existence of global oscillation modes, the so-called gravito-inertial modes. These fluid modes can couple with the rotational modes of the Earth by exerting torques on the mantle and the inner core. Viscous shear stresses at the fluid boundaries, along with pressure and gravitation, contribute to the overall torque balance. Previous research by Rogister & Valette (2009) suggests that indeed rotational and gravito-inertial modes are coupled, thus shifting the frequencies of the Chandler Wobble (CW), the Free Core Nutation (FCN) and the Free Inner Core Nutation (FICN). Here we present the first results from a numerical model of the Earth's fluid core and its interaction with the rotational eigenmodes. In this first step we consider a fluid core without a solid inner core and we restrict to ellipticities of the same order as the Ekman number. We formulate the problem as a generalised eigenvalue problem that solves simultaneously the Liouville equation for the rotational modes (the torque balance), and the Navier-Stokes equation for the inertial modes.
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NASA Astrophysics Data System (ADS)
Hemmatian, M.; Sedaghati, R.
2017-04-01
This study aims at developing a finite element model to predict the sound transmission loss (STL) of a multilayer panel partially treated with a Magnetorheological (MR) fluid core layer. MR fluids are smart materials with promising controllable rheological characteristics in which the application of an external magnetic field instantly changes their rheological properties. Partial treatment of sandwich panels with MR fluid core layer provides an opportunity to change stiffness and damping of the structure without significantly increasing the mass. The STL of a finite sandwich panel partially treated with MR fluid is modeled using the finite element (FE) method. Circular sandwich panels with clamped boundary condition and elastic face sheets in which the core layer is segmented circumferentially is considered. The MR fluid core layer is considered as a viscoelastic material with complex shear modulus with the magnetic field and frequency dependent storage and loss moduli. Neglecting the effect of the panel's vibration on the pressure forcing function, the work done by the acoustic pressure is expressed as a function of the blocked pressure in order to calculate the force vector in the equation of the motion of the panel. The governing finite element equation of motion of the MR sandwich panel is then developed to predict the transverse vibration of the panel which can then be utilized to obtain the radiated sound using Green's function. The developed model is used to conduct a systematic parametric study on the effect of different locations of MR fluid treatment on the natural frequencies and the STL.
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Convectively driven decadal zonal accelerations in Earth's fluid core
NASA Astrophysics Data System (ADS)
More, Colin; Dumberry, Mathieu
2018-04-01
Azimuthal accelerations of cylindrical surfaces co-axial with the rotation axis have been inferred to exist in Earth's fluid core on the basis of magnetic field observations and changes in the length-of-day. These accelerations have a typical timescale of decades. However, the physical mechanism causing the accelerations is not well understood. Scaling arguments suggest that the leading order torque averaged over cylindrical surfaces should arise from the Lorentz force. Decadal fluctuations in the magnetic field inside the core, driven by convective flows, could then force decadal changes in the Lorentz torque and generate zonal accelerations. We test this hypothesis by constructing a quasi-geostrophic model of magnetoconvection, with thermally driven flows perturbing a steady, imposed background magnetic field. We show that when the Alfvén number in our model is similar to that in Earth's fluid core, temporal fluctuations in the torque balance are dominated by the Lorentz torque, with the latter generating mean zonal accelerations. Our model reproduces both fast, free Alfvén waves and slow, forced accelerations, with ratios of relative strength and relative timescale similar to those inferred for the Earth's core. The temporal changes in the magnetic field which drive the time-varying Lorentz torque are produced by the underlying convective flows, shearing and advecting the magnetic field on a timescale associated with convective eddies. Our results support the hypothesis that temporal changes in the magnetic field deep inside Earth's fluid core drive the observed decadal zonal accelerations of cylindrical surfaces through the Lorentz torque.
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NASA Astrophysics Data System (ADS)
Molli, G.; Cortecci, G.; Vaselli, L.; Ottria, G.; Cortopassi, A.; Dinelli, E.; Mussi, M.; Barbieri, M.
2010-09-01
We studied the geometry, intensity of deformation and fluid-rock interaction of a high angle normal fault within Carrara marble in the Alpi Apuane NW Tuscany, Italy. The fault is comprised of a core bounded by two major, non-parallel slip surfaces. The fault core, marked by crush breccia and cataclasites, asymmetrically grades to the host protolith through a damage zone, which is well developed only in the footwall block. On the contrary, the transition from the fault core to the hangingwall protolith is sharply defined by the upper main slip surface. Faulting was associated with fluid-rock interaction, as evidenced by kinematically related veins observable in the damage zone and fluid channelling within the fault core, where an orange-brownish cataclasite matrix can be observed. A chemical and isotopic study of veins and different structural elements of the fault zone (protolith, damage zone and fault core), including a mathematical model, was performed to document type, role, and activity of fluid-rock interactions during deformation. The results of our studies suggested that deformation pattern was mainly controlled by processes associated with a linking-damage zone at a fault tip, development of a fault core, localization and channelling of fluids within the fault zone. Syn-kinematic microstructural modification of calcite microfabric possibly played a role in confining fluid percolation.
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Initial Coupling of the RELAP-7 and PRONGHORN Applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
J. Ortensi; D. Andrs; A.A. Bingham
2012-10-01
Modern nuclear reactor safety codes require the ability to solve detailed coupled neutronic- thermal fluids problems. For larger cores, this implies fully coupled higher dimensionality spatial dynamics with appropriate feedback models that can provide enough resolution to accurately compute core heat generation and removal during steady and unsteady conditions. The reactor analysis code PRONGHORN is being coupled to RELAP-7 as a first step to extend RELAP’s current capabilities. This report details the mathematical models, the type of coupling, and the testing results from the integrated system. RELAP-7 is a MOOSE-based application that solves the continuity, momentum, and energy equations inmore » 1-D for a compressible fluid. The pipe and joint capabilities enable it to model parts of the power conversion unit. The PRONGHORN application, also developed on the MOOSE infrastructure, solves the coupled equations that define the neutron diffusion, fluid flow, and heat transfer in a full core model. The two systems are loosely coupled to simplify the transition towards a more complex infrastructure. The integration is tested on a simplified version of the OECD/NEA MHTGR-350 Coupled Neutronics-Thermal Fluids benchmark model.« less
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Critical asymmetry in renormalization group theory for fluids.
Zhao, Wei; Wu, Liang; Wang, Long; Li, Liyan; Cai, Jun
2013-06-21
The renormalization-group (RG) approaches for fluids are employed to investigate critical asymmetry of vapour-liquid equilibrium (VLE) of fluids. Three different approaches based on RG theory for fluids are reviewed and compared. RG approaches are applied to various fluid systems: hard-core square-well fluids of variable ranges, hard-core Yukawa fluids, and square-well dimer fluids and modelling VLE of n-alkane molecules. Phase diagrams of simple model fluids and alkanes described by RG approaches are analyzed to assess the capability of describing the VLE critical asymmetry which is suggested in complete scaling theory. Results of thermodynamic properties obtained by RG theory for fluids agree with the simulation and experimental data. Coexistence diameters, which are smaller than the critical densities, are found in the RG descriptions of critical asymmetries of several fluids. Our calculation and analysis show that the approach coupling local free energy with White's RG iteration which aims to incorporate density fluctuations into free energy is not adequate for VLE critical asymmetry due to the inadequate order parameter and the local free energy functional used in the partition function.
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Development of an Efficient CFD Model for Nuclear Thermal Thrust Chamber Assembly Design
NASA Technical Reports Server (NTRS)
Cheng, Gary; Ito, Yasushi; Ross, Doug; Chen, Yen-Sen; Wang, Ten-See
2007-01-01
The objective of this effort is to develop an efficient and accurate computational methodology to predict both detailed thermo-fluid environments and global characteristics of the internal ballistics for a hypothetical solid-core nuclear thermal thrust chamber assembly (NTTCA). Several numerical and multi-physics thermo-fluid models, such as real fluid, chemically reacting, turbulence, conjugate heat transfer, porosity, and power generation, were incorporated into an unstructured-grid, pressure-based computational fluid dynamics solver as the underlying computational methodology. The numerical simulations of detailed thermo-fluid environment of a single flow element provide a mechanism to estimate the thermal stress and possible occurrence of the mid-section corrosion of the solid core. In addition, the numerical results of the detailed simulation were employed to fine tune the porosity model mimic the pressure drop and thermal load of the coolant flow through a single flow element. The use of the tuned porosity model enables an efficient simulation of the entire NTTCA system, and evaluating its performance during the design cycle.
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The Geomagnetic Field as a Transient: Constraints From Paleomagnetic Intensity Data
NASA Astrophysics Data System (ADS)
Aldridge, K. D.; Baker, R.; McMillan, D. G.
2009-12-01
Measurement of Earth’s magnetic field intensity from sedimentary rocks confirms that the field is a transient on millennial time scales. In accounting for this observation, parameters from dynamo models need to be compared with those obtained from observations. Here we model temporal changes in intensity of the geomagnetic field as either growths or decays, sometimes separated by stationary states. In order to obtain temporal properties of the geomagnetic field, our model, developed as a Matlab algorithm, searches records of relative paleointensity to measure objectively the rates of growth and decay of the field. Here we report on the application of our algorithm to six records of relative paleointensity obtained from oceanic cores. Our model for the fluid velocity field in Earth’s core is based on parametric instability produced externally through gradients of the gravitational field. It is well known that these gradients can lead to instability of the core fluid through both elliptical and shear straining of fluid streamlines. Such an instability will exist as long as the externally produced strain rate exceeds the dissipation rate in Earth’s fluid core. As known from both theoretical models and experimental observations that a sequence of alternately growing and decaying velocities will develop in the fluid, our algorithm has searched the records of relative paleointensity for exponential growths and decays. Since a balance may exist between strain and decay rates described above, our algorithm includes the possibility for a segment of relative paleointensity that is stationary. Such segments do indeed occur in the relative paleointensity record and are expected by the model of parametric instability. Results of the application of our algorithm spanning two Ma with broad geographical coverage will be presented.
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Magnetohydrodynamic Convection in the Outer Core and its Geodynamic Consequences
NASA Technical Reports Server (NTRS)
Kuang, Weijia; Chao, Benjamin F.; Fang, Ming
2004-01-01
The Earth's fluid outer core is in vigorous convection through much of the Earth's history. In addition to generating and maintaining Earth s time-varying magnetic field (geodynamo), the core convection also generates mass redistribution in the core and a dynamical pressure field on the core-mantle boundary (CMB). All these shall result in various core-mantle interactions, and contribute to surface geodynamic observables. For example, electromagnetic core-mantle coupling arises from finite electrically conducting lower mantle; gravitational interaction occurs between the cores and the heterogeneous mantle; mechanical coupling may also occur when the CMB topography is aspherical. Besides changing the mantle rotation via the coupling torques, the mass-redistribution in the core shall produce a spatial-temporal gravity anomaly. Numerical modeling of the core dynamical processes contributes in several geophysical disciplines. It helps explain the physical causes of surface geodynamic observables via space geodetic techniques and other means, e.g. Earth's rotation variation on decadal time scales, and secular time-variable gravity. Conversely, identification of the sources of the observables can provide additional insights on the dynamics of the fluid core, leading to better constraints on the physics in the numerical modeling. In the past few years, our core dynamics modeling efforts, with respect to our MoSST model, have made significant progress in understanding individual geophysical consequences. However, integrated studies are desirable, not only because of more mature numerical core dynamics models, but also because of inter-correlation among the geophysical phenomena, e.g. mass redistribution in the outer core produces not only time-variable gravity, but also gravitational core-mantle coupling and thus the Earth's rotation variation. They are expected to further facilitate multidisciplinary studies of core dynamics and interactions of the core with other components of the Earth.
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Fluid flow near the surface of earth's outer core
NASA Technical Reports Server (NTRS)
Bloxham, Jeremy; Jackson, Andrew
1991-01-01
This review examines the recent attempts at extracting information on the pattern of fluid flow near the surface of the outer core from the geomagnetic secular variation. Maps of the fluid flow at the core surface are important as they may provide some insight into the process of the geodynamo and may place useful constraints on geodynamo models. In contrast to the case of mantle convection, only very small lateral variations in core density are necessary to drive the flow; these density variations are, by several orders of magnitude, too small to be imaged seismically; therefore, the geomagnetic secular variation is utilized to infer the flow. As substantial differences exist between maps developed by different researchers, the possible underlying reasons for these differences are examined with particular attention given to the inherent problems of nonuniqueness.
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Numerical modeling of fluid flow in a fault zone: a case of study from Majella Mountain (Italy).
NASA Astrophysics Data System (ADS)
Romano, Valentina; Battaglia, Maurizio; Bigi, Sabina; De'Haven Hyman, Jeffrey; Valocchi, Albert J.
2017-04-01
The study of fluid flow in fractured rocks plays a key role in reservoir management, including CO2 sequestration and waste isolation. We present a numerical model of fluid flow in a fault zone, based on field data acquired in Majella Mountain, in the Central Apennines (Italy). This fault zone is considered a good analogue for the massive presence of fluid migration in the form of tar. Faults are mechanical features and cause permeability heterogeneities in the upper crust, so they strongly influence fluid flow. The distribution of the main components (core, damage zone) can lead the fault zone to act as a conduit, a barrier, or a combined conduit-barrier system. We integrated existing information and our own structural surveys of the area to better identify the major fault features (e.g., type of fractures, statistical properties, geometrical and petro-physical characteristics). In our model the damage zones of the fault are described as discretely fractured medium, while the core of the fault as a porous one. Our model utilizes the dfnWorks code, a parallelized computational suite, developed at Los Alamos National Laboratory (LANL), that generates three dimensional Discrete Fracture Network (DFN) of the damage zones of the fault and characterizes its hydraulic parameters. The challenge of the study is the coupling between the discrete domain of the damage zones and the continuum one of the core. The field investigations and the basic computational workflow will be described, along with preliminary results of fluid flow simulation at the scale of the fault.
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Enhanced Microfluidic Electromagnetic Measurements
NASA Technical Reports Server (NTRS)
Ricco, Antonio J. (Inventor); Kovacs, Gregory (Inventor); Giovangrandi, Laurent (Inventor)
2015-01-01
Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.
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Mathematical modelling of fluid transport and its regulation at multiple scales.
Chara, Osvaldo; Brusch, Lutz
2015-04-01
Living matter equals water, to a first approximation, and water transport across barriers such as membranes and epithelia is vital. Water serves two competing functions. On the one hand, it is the fundamental solvent enabling random mobility of solutes and therefore biochemical reactions and intracellular signal propagation. Homeostasis of the intracellular water volume is required such that messenger concentration encodes the stimulus and not inverse volume fluctuations. On the other hand, water flow is needed for transport of solutes to and away from cells in a directed manner, threatening volume homeostasis and signal transduction fidelity of cells. Feedback regulation of fluid transport reconciles these competing objectives. The regulatory mechanisms often span across multiple spatial scales from cellular interactions up to the architecture of organs. Open questions relate to the dependency of water fluxes and steady state volumes on control parameters and stimuli. We here review selected mathematical models of feedback regulation of fluid transport at the cell scale and identify a general "core-shell" structure of such models. We propose that fluid transport models at other spatial scales can be constructed in a generalised core-shell framework, in which the core accounts for the biophysical effects of fluid transport whilst the shell reflects the regulatory mechanisms. We demonstrate the applicability of this framework for tissue lumen growth and suggest future experiments in zebrafish to test lumen size regulation mechanisms. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Riegel, H. B.; Zambrano, M.; Jablonska, D.; Emanuele, T.; Agosta, F.; Mattioni, L.; Rustichelli, A.
2017-12-01
The hydraulic properties of fault zones depend upon the individual contributions of the damage zone and the fault core. In the case of the damage zone, it is generally characterized by means of fracture analysis and modelling implementing multiple approaches, for instance the discrete fracture network model, the continuum model, and the channel network model. Conversely, the fault core is more difficult to characterize because it is normally composed of fine grain material generated by friction and wear. If the dimensions of the fault core allows it, the porosity and permeability are normally studied by means of laboratory analysis or in the other case by two dimensional microporosity analysis and in situ measurements of permeability (e.g. micro-permeameter). In this study, a combined approach consisting of fracture modeling, three-dimensional microporosity analysis, and computational fluid dynamics was applied to characterize the hydraulic properties of fault zones. The studied fault zones crosscut a well-cemented heterolithic succession (sandstone and mudstones) and may vary in terms of fault core thickness and composition, fracture properties, kinematics (normal or strike-slip), and displacement. These characteristics produce various splay and fault core behavior. The alternation of sandstone and mudstone layers is responsible for the concurrent occurrence of brittle (fractures) and ductile (clay smearing) deformation. When these alternating layers are faulted, they produce corresponding fault cores which act as conduits or barriers for fluid migration. When analyzing damage zones, accurate field and data acquisition and stochastic modeling was used to determine the hydraulic properties of the rock volume, in relation to the surrounding, undamaged host rock. In the fault cores, the three-dimensional pore network quantitative analysis based on X-ray microtomography images includes porosity, pore connectivity, and specific surface area. In addition, images were used to perform computational fluid simulation (Lattice-Boltzmann multi relaxation time method) and estimate the permeability. These results will be useful for understanding the deformation process and hydraulic properties across meter-scale damage zones.
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Ring waves as a mass transport mechanism in air-driven core-annular flows.
Camassa, Roberto; Forest, M Gregory; Lee, Long; Ogrosky, H Reed; Olander, Jeffrey
2012-12-01
Air-driven core-annular fluid flows occur in many situations, from lung airways to engineering applications. Here we study, experimentally and theoretically, flows where a viscous liquid film lining the inside of a tube is forced upwards against gravity by turbulent airflow up the center of the tube. We present results on the thickness and mean speed of the film and properties of the interfacial waves that develop from an instability of the air-liquid interface. We derive a long-wave asymptotic model and compare properties of its solutions with those of the experiments. Traveling wave solutions of this long-wave model exhibit evidence of different mass transport regimes: Past a certain threshold, sufficiently large-amplitude waves begin to trap cores of fluid which propagate upward at wave speeds. This theoretical result is then confirmed by a second set of experiments that show evidence of ring waves of annular fluid propagating over the underlying creeping flow. By tuning the parameters of the experiments, the strength of this phenomenon can be adjusted in a way that is predicted qualitatively by the model.
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NASA Technical Reports Server (NTRS)
Kadambi, J. R.; Schneider, S. J.; Stewart, W. A.
1986-01-01
The natural circulation of a single phase fluid in a scale model of a pressurized water reactor system during a postulated grade core accident is analyzed. The fluids utilized were water and SF6. The design of the reactor model and the similitude requirements are described. Four LDA tests were conducted: water with 28 kW of heat in the simulated core, with and without the participation of simulated steam generators; water with 28 kW of heat in the simulated core, with the participation of simulated steam generators and with cold upflow of 12 lbm/min from the lower plenum; and SF6 with 0.9 kW of heat in the simulated core and without the participation of the simulated steam generators. For the water tests, the velocity of the water in the center of the core increases with vertical height and continues to increase in the upper plenum. For SF6, it is observed that the velocities are an order of magnitude higher than those of water; however, the velocity patterns are similar.
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Heat Pipe Reactor Dynamic Response Tests: SAFE-100 Reactor Core Prototype
NASA Technical Reports Server (NTRS)
Bragg-Sitton, Shannon M.
2005-01-01
The SAFE-I00a test article at the NASA Marshall Space Flight Center was used to simulate a variety of potential reactor transients; the SAFEl00a is a resistively heated, stainless-steel heat-pipe (HP)-reactor core segment, coupled to a gas-flow heat exchanger (HX). For these transients the core power was controlled by a point kinetics model with reactivity feedback based on core average temperature; the neutron generation time and the temperature feedback coefficient are provided as model inputs. This type of non-nuclear test is expected to provide reasonable approximation of reactor transient behavior because reactivity feedback is very simple in a compact fast reactor (simple, negative, and relatively monotonic temperature feedback, caused mostly by thermal expansion) and calculations show there are no significant reactivity effects associated with fluid in the HP (the worth of the entire inventory of Na in the core is .
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Fast torsional waves and strong magnetic field within the Earth's core.
Gillet, Nicolas; Jault, Dominique; Canet, Elisabeth; Fournier, Alexandre
2010-05-06
The magnetic field inside the Earth's fluid and electrically conducting outer core cannot be directly probed. The root-mean-squared (r.m.s.) intensity for the resolved part of the radial magnetic field at the core-mantle boundary is 0.3 mT, but further assumptions are needed to infer the strength of the field inside the core. Recent diagnostics obtained from numerical geodynamo models indicate that the magnitude of the dipole field at the surface of a fluid dynamo is about ten times weaker than the r.m.s. field strength in its interior, which would yield an intensity of the order of several millitesla within the Earth's core. However, a 60-year signal found in the variation in the length of day has long been associated with magneto-hydrodynamic torsional waves carried by a much weaker internal field. According to these studies, the r.m.s. strength of the field in the cylindrical radial direction (calculated for all length scales) is only 0.2 mT, a figure even smaller than the r.m.s. strength of the large-scale (spherical harmonic degree n
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Mandea, Mioara; Panet, Isabelle; Lesur, Vincent; de Viron, Olivier; Diament, Michel; Le Mouël, Jean-Louis
2012-11-20
To understand the dynamics of the Earth's fluid, iron-rich outer core, only indirect observations are available. The Earth's magnetic field, originating mainly within the core, and its temporal variations can be used to infer the fluid motion at the top of the core, on a decadal and subdecadal time-scale. Gravity variations resulting from changes in the mass distribution within the Earth may also occur on the same time-scales. Such variations include the signature of the flow inside the core, though they are largely dominated by the water cycle contributions. Our study is based on 8 y of high-resolution, high-accuracy magnetic and gravity satellite data, provided by the CHAMP and GRACE missions. From the newly derived geomagnetic models we have computed the core magnetic field, its temporal variations, and the core flow evolution. From the GRACE CNES/GRGS series of time variable geoid models, we have obtained interannual gravity models by using specifically designed postprocessing techniques. A correlation analysis between the magnetic and gravity series has demonstrated that the interannual changes in the second time derivative of the core magnetic field under a region from the Atlantic to Indian Ocean coincide in phase with changes in the gravity field. The order of magnitude of these changes and proposed correlation are plausible, compatible with a core origin; however, a complete theoretical model remains to be built. Our new results and their broad geophysical significance could be considered when planning new Earth observation space missions and devising more sophisticated Earth's interior models.
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ERIC Educational Resources Information Center
Tudela, Ignacio; Bonete, Pedro; Fullana, Andres; Conesa, Juan Antonio
2011-01-01
The unreacted-core shrinking (UCS) model is employed to characterize fluid-particle reactions that are important in industry and research. An approach to understand the UCS model by numerical methods is presented, which helps the visualization of the influence of the variables that control the overall heterogeneous process. Use of this approach in…
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Watson, R.
Waterflooding is the most commonly used secondary oil recovery technique. One of the requirements for understanding waterflood performance is a good knowledge of the basic properties of the reservoir rocks. This study is aimed at correlating rock-pore characteristics to oil recovery from various reservoir rock types and incorporating these properties into empirical models for Predicting oil recovery. For that reason, this report deals with the analyses and interpretation of experimental data collected from core floods and correlated against measurements of absolute permeability, porosity. wettability index, mercury porosimetry properties and irreducible water saturation. The results of the radial-core the radial-core andmore » linear-core flow investigations and the other associated experimental analyses are presented and incorporated into empirical models to improve the predictions of oil recovery resulting from waterflooding, for sandstone and limestone reservoirs. For the radial-core case, the standardized regression model selected, based on a subset of the variables, predicted oil recovery by waterflooding with a standard deviation of 7%. For the linear-core case, separate models are developed using common, uncommon and combination of both types of rock properties. It was observed that residual oil saturation and oil recovery are better predicted with the inclusion of both common and uncommon rock/fluid properties into the predictive models.« less
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NASA Astrophysics Data System (ADS)
Smit, Karen V.; Stachel, Thomas; Stern, Richard A.; Shirey, Steven B.; Steele, Andrew
2017-04-01
Traditional models for diamond formation within the lithospheric mantle invoke either carbonate reduction or methane oxidation. Both these mechanisms require some oxygen exchange with the surrounding wall-rock at the site of diamond precipitation. However, peridotite does not have sufficient buffering capacity to allow for diamond formation via these traditional models and instead peridotitic diamonds may form through isochemical cooling of H2O-rich CHO fluids [1]. Marange mixed-habit diamonds from eastern Zimbabwe provide the first natural confirmation of this new diamond growth model [2]. Although Marange diamonds do not contain any silicate or sulphide inclusions, they contain Ni-N-vacancy complexes detected through photoluminescence (PL) spectroscopy that suggest the source fluids equilibrated in the Ni-rich depleted peridotitic lithosphere. Cuboid sectors also contain abundant micro-inclusions of CH4, the first direct observation of reduced CH4-rich fluids that are thought to percolate through the lithospheric mantle [2]. In fluid inclusion-free diamonds, core-to-rim trends in δ13C and N content are used to infer the speciation of the diamond-forming fluid. Core to rim trends of increasing δ13C with decreasing N content are interpreted as diamond growth from oxidized CO2- or carbonate-bearing fluids. Diamond growth from reduced species should show the opposite trends - decreasing δ13C from core to rim with decreasing N content. Within the CH4-bearing growth sectors of Marange diamonds, however, such a 'reduced' trend is not observed. Rather, δ13C increases from core to rim within a homogeneously grown zone [2]. These contradictory observations can be explained through either mixing between CH4- and CO2-rich end-members of hydrous fluids [2] or through closed system precipitation from an already mixed CH4-CO2 H2O-maximum fluid with XCO2 (CO2/[CO2+CH4]) between 0.3 and 0.7 [3]. These results demonstrate that Marange diamonds precipitated from cooling CH4-CO2-bearing hydrous fluids rather than through redox buffering. As this growth mechanism applies to both the fluid-rich cuboid and gem-like octahedral sectors of Marange diamonds, a non-redox model for diamond formation from mixed CH4-CO2 fluids is indicated for a wider range of gem-quality peridotitic diamonds. Indeed, at the redox conditions of global diamond-bearing lithospheric mantle (FMQ -2 to -4; [4]), CHO fluids are strongly water-dominated and contain both CH4 and CO2 as dominant carbon species [5]. By contrast diamond formation in eclogitic assemblages, through either redox buffering or cooling of carbon-bearing fluids, is not as well constrained. Zimmi diamonds from the West African craton have eclogitic sulphide inclusions (with low Ni and high Re/Os) and formed at 650 Ma, overlapping with the timing of subduction [6]. In one Zimmi diamond, a core to rim trend of decreasing δ13C (-23.4 to -24.5 ) and N content is indicative of formation from reduced C2H6/CH4-rich fluids, likely derived from oceanic crust recycled during Neoproterozoic subduction. Unlike mixed CH4-CO2 fluids near the water maximum, isochemical cooling or ascent of such reduced CHO fluids is not effficient at diamond precipitation. Furthermore, measurable carbon isotopic variations in diamond are not predicted in this model and therefore cannot be reconciled with the ˜1 ‰ internal variation seen. Consequently, this Zimmi eclogitic diamond likely formed through redox buffering of reduced subduction-related fluids, infiltrating into sulphide-bearing eclogite. References 1. Luth and Stachel, 2014. CMP, 168, 1083 2. Smit et al., 2016. Lithos, 265, 68-81 3. Stachel et al., in review 4. Stagno et al., 2013. Nature, 493, 84-88 5. Zhang and Duan, 2009. GCA 73, 2089-2102 6. Smit et al., 2016. Precamb Res, 286, 152-166
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NASA Astrophysics Data System (ADS)
Wang, Zizhen; Schmitt, Douglas R.; Wang, Ruihe
2017-08-01
A core scale modeling method for viscoelastic properties of rocks saturated with viscous fluid at low frequencies is developed based on the stress-strain method. The elastic moduli dispersion of viscous fluid is described by the Maxwell's spring-dash pot model. Based on this modeling method, we numerically test the effects of frequency, fluid viscosity, porosity, pore size, and pore aspect ratio on the storage moduli and the stress-strain phase lag of saturated rocks. And we also compared the modeling results to the Hashin-Shtrikman bounds and the coherent potential approximation (CPA). The dynamic moduli calculated from the modeling are lower than the predictions of CPA, and both of these fall between the Hashin-Shtrikman bounds. The modeling results indicate that the frequency and the fluid viscosity have similar effects on the dynamic moduli dispersion of fully saturated rocks. We observed the Debye peak in the phase lag variation with the change of frequency and viscosity. The pore structure parameters, such as porosity, pore size, and aspect ratio affect the rock frame stiffness and result in different viscoelastic behaviors of the saturated rocks. The stress-strain phase lags are larger with smaller stiffness contrasts between the rock frame and the pore fluid. The viscoelastic properties of saturated rocks are more sensitive to aspect ratio compared to other pore structure parameters. The results suggest that significant seismic dispersion (at about 50-200 Hz) might be expected for both compressional and shear waves passing through rocks saturated with highly viscous fluids.
Plain Language SummaryWe develop a core scale modeling method to simulate the viscoelastic properties of rocks saturated with viscous fluid at low frequencies based on the stress-strain method. The elastic moduli dispersion of viscous fluid is described by the Maxwell's spring-dash pot model. By using this modeling method, we numerically test the effects of frequency, fluid viscosity, porosity, pore size, and pore aspect ratio on the composite's viscoelastic properties. The modeling results indicate that the frequency and the fluid viscosity have similar effects on the dynamic moduli dispersion of fully saturated rocks. We observed the Debye peak in the phase lag variation with the change of frequency and viscosity. The pore structure parameters, such as porosity, pore size, and pore aspect ratio affect the rock frame stiffness and result in different viscoelastic behavior of the saturated rocks. The lower the rock frame stiffness, the larger the stress-strain phase lags. The viscoelastic properties of saturated rocks are more sensitive to the pore aspect ratio. The results suggest that significant seismic dispersion might be expected for both compressional and shear waves passing through rocks saturated with highly viscous fluids. This will be important in the context of heavy hydrocarbon reservoirs and igneous rocks saturated with silicate melt.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T52A..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T52A..03L"><span>How can fluid overpressures be developed and maintained in crustal fault zones ?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>LECLÈRE, H.; Cappa, F.; Faulkner, D. R.; Armitage, P. J.; Blake, O. O.; Fabbri, O.</p> <p>2013-12-01</p> <p>The presence of fluid overpressure in crustal fault zones is known to play a key role on the stability of faults and it has often been invoked to explain the triggering of earthquakes and the apparent weakness of misoriented faults. However, the mechanisms allowing the development and maintenance of fluid overpressures in fault remain unresolved. We investigate how fluid overpressures can be developed and maintained in complex fault zones with hydraulic and elastic heterogeneities. Here we address this question combining geological observations, laboratory experiments and hydromechanical models of an active crustal fault zone in the Ubaye-Argentera area (southeastern France). The fault zone studied is located in the Argentera external crystalline massif and is connected to regional NW-SE steeply-dipping dextral strike-slip faults with an offset of several kilometers. The fault zone cuts through migmatitic gneisses composed of quartz, K-feldspar, plagioclase, biotite and muscovite. It exposes several anastomosing core zones surrounded by damage zones with a pluri-decametric total width. The core zones are made up of centimetric to pluridecimetric phyllosilicate-rich gouge layers while the damage zones are composed of pluri-metric phyllonitic rock derived from mylonite. The determination of fault structure in the field and its hydraulic and mechanical properties in the lab are key aspects to improve our understanding of the role of fluids in fault mechanics and earthquake triggering. Here, the permeability and elastic moduli of the host rock, damage zone and fault core were measured from natural plugs with a diameter of 20 mm and lengths between 26 to 51 mm, using a high-pressure hydrostatic fluid-flow apparatus. Measurements were made with confining pressures ranging from 30 to 210 MPa and using argon pore fluid pressure of 20 MPa. Data show a reduction of the permeability values of one order of magnitude between host rock and fault damage zone and a decrease of 50% of the elastic properties between host rock and core zone. Data also show a higher dependence of the permeability on the effective pressure for the host rock compared with the damage zone and core zone. This heterogeneity of properties is related to the development of different microstructures such as microcracks, S-C structures and microbreccia across the fault zone achieved during the tectonic history of the fault. From these physical property values and the fault zone architecture, we then analyzed the effects of sudden mechanical loading approximating to static normal-stress transfer following an earthquake on a neighbouring fault, on the development of fluid overpressures. A series of 1-D hydromechanical numerical models was used to show that sudden normal stress increase is a viable mechanism for fluid overpressuring in the studied fault-zone. The models also showed that fluid overpressures can be temporarily maintained in the studied fault zone and that the maintenance of fluid overpressures is controlled by the structure and fluid-flow properties of the fault zone.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LPICo2085.6009S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LPICo2085.6009S"><span>Modeling Rock Alteration at the Water-Rock Interface of Icy Moons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Semprich, J.; Treiman, A. H.; Schwenzer, S. P.</p> <p>2018-05-01</p> <p>Alteration phases of a CM rock core are modeled with variations in fluid composition at the water-rock interface of icy moons. In the presence of H2O, CO2, CH4, and H2 serpentinization of the rock core is very likely at low pressures and 200–400 °C.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870010214','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870010214"><span>Feasibility analysis of reciprocating magnetic heat pumps</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Larson, A. V.; Hartley, J. G.; Shelton, S. V.; Smith, M. M.</p> <p>1986-01-01</p> <p>The conceptual design selected for detailed system analysis and optimization is the reciprocating gadolinium core in a regenerative fluid column within the bore of a superconducting magnet. The thermodynamic properties of gadolinium are given. A computerized literature search for relevant papers was conducted and is being analyzed. Contact was made with suppliers of superconducting magnets and accessories, magnetic materials, and various types of hardware. A description of the model for the thermal analysis of the core and regenerator fluids is included.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhFl...18f2101R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhFl...18f2101R"><span>Evolution of a compound droplet attached to a core-shell nozzle under the action of a strong electric field</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reznik, S. N.; Yarin, A. L.; Zussman, E.; Bercovici, L.</p> <p>2006-06-01</p> <p>The shape evolution of small compound droplets at the exit of a core-shell system in the presence of a sufficiently strong electric field is studied both experimentally and theoretically. It is shown that the jetting effect at the tip of the shell nozzle does not necessarily cause entrainment of the core fluid, in which case the co-electrospinning process fails to produce core-shell nanofibers. The remedy lies in extending the core nozzle outside its shell counterpart by about half the radius of the latter. The results also show that the free charges migrate very rapidly from both fluids and their interface to the free surface of the shell. This reflects the fact that most of the prejetting evolution of the droplet can be effectively described in terms of the perfect conductor model, even though the fluids can be characterized as leaky dielectrics. The stress level at the core-shell interface is of the order of 5×103g/(cms2), the relevant value in assessing the viability of viruses, bacteria, DNA molecules, drugs, enzymes, chromophores, and proteins to be encapsulated in nanofibers via co-electrospinning.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5789681-dynamic-two-fluid-model-olga-theory-application','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5789681-dynamic-two-fluid-model-olga-theory-application"><span>The dynamic two-fluid model OLGA; Theory and application</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bendiksen, K.H.; Maines, D.; Moe, R.</p> <p>1991-05-01</p> <p>Dynamic two-fluid models have found a wide range of application in the simulation of two-phase-flow systems, particularly for the analysis of steam/water flow in the core of a nuclear reactor. Until quite recently, however, very few attempts have been made to use such models in the simulation of two-phase oil and gas flow in pipelines. This paper presents a dynamic two-fluid model, OLGA, in detail, stressing the basic equations and the two-fluid models applied. Predictions of steady-state pressure drop, liquid hold-up, and flow-regime transitions are compared with data from the SINTEF Two-Phase Flow Laboratory and from the literature. Comparisons withmore » evaluated field data are also presented.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22403229-spreading-ferrofluid-core-three-stream-micromixer-channels','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22403229-spreading-ferrofluid-core-three-stream-micromixer-channels"><span>Spreading of a ferrofluid core in three-stream micromixer channels</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wang, Zhaomeng; Varma, V. B.; Ramanujan, R. V., E-mail: ramanujan@ntu.edu.sg</p> <p>2015-05-15</p> <p>Spreading of a water based ferrofluid core, cladded by a diamagnetic fluid, in three-stream micromixer channels was studied. This spreading, induced by an external magnetic field, is known as magnetofluidic spreading (MFS). MFS is useful for various novel applications where control of fluid-fluid interface is desired, such as micromixers or micro-chemical reactors. However, fundamental aspects of MFS are still unclear, and a model without correction factors is lacking. Hence, in this work, both experimental and numerical analyses were undertaken to study MFS. We show that MFS increased for higher applied magnetic fields, slower flow speed of both fluids, smaller flowmore » rate of ferrofluid relative to cladding, and higher initial magnetic particle concentration. Spreading, mainly due to connective diffusion, was observed mostly near the channel walls. Our multi-physics model, which combines magnetic and fluidic analyses, showed, for the first time, excellent agreement between theory and experiment. These results can be useful for lab-on-a-chip devices.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhFl...27e2004W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhFl...27e2004W"><span>Spreading of a ferrofluid core in three-stream micromixer channels</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zhaomeng; Varma, V. B.; Xia, Huan Ming; Wang, Z. P.; Ramanujan, R. V.</p> <p>2015-05-01</p> <p>Spreading of a water based ferrofluid core, cladded by a diamagnetic fluid, in three-stream micromixer channels was studied. This spreading, induced by an external magnetic field, is known as magnetofluidic spreading (MFS). MFS is useful for various novel applications where control of fluid-fluid interface is desired, such as micromixers or micro-chemical reactors. However, fundamental aspects of MFS are still unclear, and a model without correction factors is lacking. Hence, in this work, both experimental and numerical analyses were undertaken to study MFS. We show that MFS increased for higher applied magnetic fields, slower flow speed of both fluids, smaller flow rate of ferrofluid relative to cladding, and higher initial magnetic particle concentration. Spreading, mainly due to connective diffusion, was observed mostly near the channel walls. Our multi-physics model, which combines magnetic and fluidic analyses, showed, for the first time, excellent agreement between theory and experiment. These results can be useful for lab-on-a-chip devices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860029592&hterms=electromagnetism&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delectromagnetism','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860029592&hterms=electromagnetism&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delectromagnetism"><span>On the coupling of fluid dynamics and electromagnetism at the top of the earth's core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benton, E. R.</p> <p>1985-01-01</p> <p>A kinematic approach to short-term geomagnetism has recently been based upon pre-Maxwell frozen-flux electromagnetism. A complete dynamic theory requires coupling fluid dynamics to electromagnetism. A geophysically plausible simplifying assumption for the vertical vorticity balance, namely that the vertical Lorentz torque is negligible, is introduced and its consequences are developed. The simplified coupled magnetohydrodynamic system is shown to conserve a variety of magnetic and vorticity flux integrals. These provide constraints on eligible models for the geomagnetic main field, its secular variation, and the horizontal fluid motions at the top of the core, and so permit a number of tests of the underlying assumptions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060047476','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060047476"><span>Multiphysics Analysis of a Solid-Core Nuclear Thermal Engine Thrust Chamber</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Ten-See; Canabal, Francisco; Cheng, Gary; Chen, Yen-Sen</p> <p>2006-01-01</p> <p>The objective of this effort is to develop an efficient and accurate thermo-fluid computational methodology to predict environments for a hypothetical solid-core, nuclear thermal engine thrust chamber. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics methodology. Formulations for heat transfer in solids and porous media were implemented and anchored. A two-pronged approach was employed in this effort: A detailed thermo-fluid analysis on a multi-channel flow element for mid-section corrosion investigation; and a global modeling of the thrust chamber to understand the effect of hydrogen dissociation and recombination on heat transfer and thrust performance. The formulations and preliminary results on both aspects are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016895','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016895"><span>Exploration drilling and reservoir model of the Platanares geothermal system, Honduras, Central America</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Goff, F.; Goff, S.J.; Kelkar, S.; Shevenell, L.; Truesdell, A.H.; Musgrave, J.; Rufenacht, H.; Flores, W.</p> <p>1991-01-01</p> <p>Results of drilling, logging, and testing of three exploration core holes, combined with results of geologic and hydrogeochemical investigations, have been used to present a reservoir model of the Platanares geothermal system, Honduras. Geothermal fluids circulate at depths ??? 1.5 km in a region of active tectonism devoid of Quaternary volcanism. Large, artesian water entries of 160 to 165??C geothermal fluid in two core holes at 625 to 644 m and 460 to 635 m depth have maximum flow rates of roughly 355 and 560 l/min, respectively, which are equivalent to power outputs of about 3.1 and 5.1 MW(thermal). Dilute, alkali-chloride reservoir fluids (TDS ??? 1200 mg/kg) are produced from fractured Miocene andesite and Cretaceous to Eocene redbeds that are hydrothermally altered. Fracture permeabillity in producing horizons is locally greater than 1500 and bulk porosity is ??? 6%. A simple, fracture-dominated, volume-impedance model assuming turbulent flow indicates that the calculated reservoir storage capacity of each flowing hole is approximately 9.7 ?? 106 l/(kg cm-2), Tritium data indicate a mean residence time of 450 yr for water in the reservoir. Multiplying the natural fluid discharge rate by the mean residence time gives an estimated water volume of the Platanares system of ??? 0.78 km3. Downward continuation of a 139??C/km "conductive" gradient at a depth of 400 m in a third core hole implies that the depth to a 225??C source reservoir (predicted from chemical geothermometers) is at least 1.5 km. Uranium-thorium disequilibrium ages on calcite veins at the surface and in the core holes indicate that the present Platanares hydrothermal system has been active for the last 0.25 m.y. ?? 1991.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4137R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4137R"><span>Key characteristics of the Fe-snow regime in Ganymede's core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rückriemen, Tina; Breuer, Doris; Spohn, Tilman</p> <p>2014-05-01</p> <p>Ganymede shows signs of an internally produced dipolar magnetic field (|Bdip|≡719 nT) [1]. For small planetary bodies such as Ganymede the Fe-snow regime, i.e. the top-down solidification of iron, has been suggested to play an important role in the core cooling history [2,3]. In that regime, iron crystals form first at the core-mantle boundary (CMB) due to shallow or negative slopes of the melting temperature [2,3]. The solid iron particles are heavier than the surrounding Fe-FeS fluid, i.e. a snow zone forms, settle to deeper core regions, where the core temperature is higher than the melting temperature, and remelt again. As a consequence, a stable chemical gradient in the Fe-FeS fluid arises within the snow zone. We speculate this style of convection via sedimentation to be small scale, therefore it lacks an important criterion necessary for dynamo action [4]. Below this zone, whose thickness increases with time, the process of remelting of iron creates a gravitationally unstable situation. We propose that this could be the driving mechanism for a potential dynamo. However, dynamo action would be restricted to the time period the snow zone needs to grow across the core. With a 1D thermo-chemical evolution model, we investigate key characteristics of the Fe-snow regime within Ganymede's core: the compositional density gradient of the fluid Fe-FeS within the snow zone and the time period necessary to grow the snow zone across the core. Additionally, we determine the dipolar magnetic field strength associated with a dynamo in Ganymede's deeper fluid core. We vary important input paramters such as the initial sulfur concentration (7-19 wt.%), the core heat flux (2-6 mW/m2) and the thermal conductivity (20-60 W/mK) with the nominal model being: xs=10 wt.%, qcmb=4 mW/m2, kc=32 W/mK. We find, that heat fluxes higher than 6 or 22 mW/m2 are required for double-diffusive or overturning convection to overcome the compositional density gradient within the snow zone, respectively. Since Ganymede's core heat flux does not exceed values of 4 mW/m2 [2], we consider the snow zone to be stable against thermal convection. The time necessary to grow the snow zone across the core is between 230-1900 Myr. For representative models we calculate the temporal evolution of the surface dipolar magnetic field strength according to [5]. All models show surface dipolar magnetic field strengths during the evolution of the snow zone that match the observed value of |Bdip|≡719 nT. In conclusion, we find that the Fe-snow regime produces a stably-stratified liquid layer in the snow zone below which a magnetic field of observed strength can be generated. Such a chemical dynamo is restricted in time and stops as soon as an inner solid core starts to grow suggesting the absence of such an inner core in Ganymede. The present model further suggests a core with high initial sulfur concentration, because this leads to a late start and a long duration of the dynamo necessary to explain the present magnetic field. References [1] Kivelson, M et al. (1996), Nature, 384(6609), [2] Hauck II, S. et al. (2006), JGR, 111(E9), [3] Williams, Q. (2009), EPSL, 284(3), [4] Christensen, U. and J. Wicht (2007), Treatise of Geophysics, Elsevier, [5] Christensen, U., and J. Aubert (2006), GJI, 166(1)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050180800','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050180800"><span>Lunar Fluid Core and Solid-Body Tides</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.</p> <p>2005-01-01</p> <p>Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2-5] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening has been improving [3,5] and now seems significant. This strengthens the case for a fluid lunar core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.5812B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.5812B"><span>The Green River natural analogue as a field laboratory to study the long-term fate of CO2 in the subsurface</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Busch, Andreas; Kampman, Niko; Hangx, Suzanne; Bertier, Pieter; Bickle, Mike; Harrington, Jon</p> <p>2015-04-01</p> <p>Understanding the long-term response of CO2 injected into porous reservoirs is one of the most important aspects to demonstrate safe and permanent storage. At the same time this is one of the least understood aspects of CCS in general. The reasons are that 'long-term', in the sense of hundreds to thousands of years, is impractical from a laboratory and rather idealised from a reservoir modelling perspective. However understanding the coupled long-term hydro-chemical-mechanical response of a reservoir-seal pair following CO2 injection is highly desirable to improve confidence and trust from a regulator and societal perspective, as well as to improve risk assessment and risk reduction. In order to provide one building block to advance understanding of this subject, in July 2012 Shell recovered some 300m of core from a scientific drill hole through a natural CO2 field near Green River, Utah. This core transected two sandstone formations (Entrada and Navajo) and one intervening seal layer, composed of interbedded marine clay-/silt and sandstones (Carmel Fm.). Fluid samples and core material were taken adjacent to the Little Grand Wash Fault (LGW), along which CO2-charged fluids traverse from depth to the surface and which is believed to be the migration pathway for CO2 inflow into the reservoirs. In-situ pH, CO2 concentrations, and fluid element and isotope geochemistry were determined from wireline downhole sampling of pressurized fluids taken from the Navajo reservoirs. The fluid geochemistry provides important constraints on reservoir filling by flow of CO2 -charged brines through the LGW fault damage zone, macro-scale fluid flow in the reservoirs and the state of fluid-mineral thermodynamic disequilibrium, from which the nature of the fluid-mineral reactions can be interpreted. In addition to core samples, we obtained control samples from stratigraphically equivalent outcrop locations and drill holes that were not subject to alterations by CO2 -charged fluids and served as a direct comparison to the altered samples. We obtained geomechanical, mineralogical, geochemical and petrophysical laboratory data along the entire length of the core and from the control samples. Furthermore, we performed more detailed studies through portions of the caprock in direct contact with the CO2-charged reservoirs. This was done to constrain the nature and penetration depths of the CO2-promoted fluid-mineral reaction fronts. These reactions have taken place in the last ~100,000 years, which has been set as an upper limit for the onset of CO2 influx into the formations. This data has been used as input for reactive (transport) modeling. In addition, we compared geomechanical data from the CO2 -exposed core and the unreacted control samples to assess the mechanical stability of reservoir and seal rocks in a CO2 storage complex following mineral dissolution and precipitation for thousands of years.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150007493&hterms=K2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DK2','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150007493&hterms=K2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DK2"><span>Lunar Science from Lunar Laser Ranging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.</p> <p>2013-01-01</p> <p>Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, tidal Love number k2, and moment of inertia differences. There is weaker sensitivity to flattening of the core/mantle boundary (CMB) and fluid core moment of inertia. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to variations in lunar rotation, orientation and tidal displacements. Past solutions using the LLR data have given results for Love numbers plus dissipation due to solid-body tides and fluid core. Detection of the fluid core polar minus equatorial moment of inertia difference due to CMB flattening is weakly significant. This strengthens the case for a fluid lunar core. Future approaches are considered to detect a solid inner core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..155a2012Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..155a2012Z"><span>Drainage and impregnation capillary pressure curves calculated by the X-ray CT model of Berea sandstone using Lattice Boltzmann's method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zakirov, T.; Galeev, A.; Khramchenkov, M.</p> <p>2018-05-01</p> <p>The study deals with the features of the technique for simulating the capillary pressure curves of porous media on their X-ray microtomographic images. The results of a computational experiment on the immiscible displacement of an incompressible fluid by another in the pore space represented by a digital image of the Berea sandstone are presented. For the mathematical description of two-phase fluid flow we use Lattice Boltzmann Equation (LBM), and phenomena at the fluids interface are described by the color-gradient model. Compared with laboratory studies, the evaluation of capillary pressure based on the results of a computational filtration experiment is a non-destructive method and has a number of advantages: the absence of labor for preparation of fluids and core; the possibility of modeling on the scale of very small core fragments (several mm), which is difficult to realize under experimental conditions; three-dimensional visualization of the dynamics of filling the pore space with a displacing fluid during drainage and impregnation; the possibility of carrying out multivariate calculations for specified parameters of multiphase flow (density and viscosity of fluids, surface tension, wetting contact angle). A satisfactory agreement of the capillary pressure curves during drainage with experimental results was obtained. It is revealed that with the increase in the volume of the digital image, the relative deviation of the calculated and laboratory data decreases and for cubic digital cores larger than 1 mm it does not exceed 5%. The behavior of the non-wetting fluid flow during drainage is illustrated. It is shown that flow regimes under which computational and laboratory experiments are performed the distribution of the injected phase in directions different from the gradient of the hydrodynamic drop, including the opposite ones, is characteristic. Experimentally confirmed regularities are obtained when carrying out calculations for drainage and imbibition at different values of interfacial tension. There is a close coincidence in the average diameters of permeable channels, estimated by capillary curves for different interfacial tension and pore network model. The differences do not exceed 15%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760057994&hterms=conflict+nature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconflict%2Bnature','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760057994&hterms=conflict+nature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconflict%2Bnature"><span>Some aspects of core formation in Mercury</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Solomon, S. C.</p> <p>1976-01-01</p> <p>Some questions dealing with the nature and history of a large metallic core within Mercury are considered. These include the existence of a core, its size, whether it is fluid or solid, the timescale for core formation, the geological consequences of core formation, and whether such consequences are consistent with the surface geology. Several indirect lines of evidence are discussed which suggest the presence of a large iron-rich core. A core-formation model is examined in which core infall is accompanied by an increase of 17 km in planetary radius, an increase of 700 K in mean internal temperature, and substantial melting of the mantle. It is argued that if the core differentiated from an originally homogeneous planet, that event must have predated the oldest geological units comprising most of the planetary surface. A convective dynamo model for the source of Mercury's magnetic field is shown to conflict with cosmochemical models that do not predict a substantial radiogenic heat source in the core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060046688','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060046688"><span>Multiphysics Thrust Chamber Modeling for Nuclear Thermal Propulsion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Ten-See; Cheng, Gary; Chen, Yen-Sen</p> <p>2006-01-01</p> <p>The objective of this effort is to develop an efficient and accurate thermo-fluid computational methodology to predict environments for a solid-core, nuclear thermal engine thrust chamber. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics formulation. A two-pronged approach is employed in this effort: A detailed thermo-fluid analysis on a multi-channel flow element for mid-section corrosion investigation; and a global modeling of the thrust chamber to understand the effect of heat transfer on thrust performance. Preliminary results on both aspects are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V52B..02S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V52B..02S"><span>A Holistic Model That Physicochemically Links Iron Oxide - Apatite and Iron Oxide - Copper - Gold Deposits to Magmas</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simon, A. C.; Reich, M.; Knipping, J.; Bilenker, L.; Barra, F.; Deditius, A.; Lundstrom, C.; Bindeman, I. N.</p> <p>2015-12-01</p> <p>Iron oxide-apatite (IOA) and iron oxide-copper-gold deposits (IOCG) are important sources of their namesake metals and increasingly for rare earth metals in apatite. Studies of natural systems document that IOA and IOCG deposits are often spatially and temporally related with one another and coeval magmatism. However, a genetic model that accounts for observations of natural systems remains elusive, with few observational data able to distinguish among working hypotheses that invoke meteoric fluid, magmatic-hydrothermal fluid, and immiscible melts. Here, we use Fe and O isotope data and high-resolution trace element (e.g., Ti, V, Mn, Al) data of individual magnetite grains from the world-class Los Colorados (LC) IOA deposit in the Chilean Iron Belt to elucidate the origin of IOA and IOCG deposits. Values of d56Fe range from 0.08‰ to 0.26‰, which are within the global range of ~0.06‰ to 0.5‰ for magnetite formed at magmatic conditions. Values of δ18O for magnetite and actinolite are 2.04‰ and 6.08‰, respectively, consistent with magmatic values. Ti, V, Al, and Mn are enriched in magnetite cores and decrease systematically from core to rim. Plotting [Al + Mn] vs. [Ti + V] indicates that magnetite cores are consistent with magmatic and/or magmatic-hydrothermal (i.e., porphyry) magnetites. Decreasing Al, Mn, Ti, V is consistent with a cooling trend from porphyry to Kiruna to IOCG systems. The data from LC are consistent with the following new genetic model for IOA and IOCG systems: 1) magnetite cores crystallize from silicate melt; 2) these magnetite crystals are nucleation sites for aqueous fluid that exsolves and scavenges inter alia Fe, P, S, Cu, Au from silicate melt; 3) the magnetite-fluid suspension is less dense that the surrounding magma, allowing ascent; 4) as the suspension ascends, magnetite grows in equilibrium with the fluid and takes on a magmatic-hydrothermal character (i.e., lower Al, Mn, Ti, V); 5) during ascent, magnetite, apatite and actinolite are deposited to form IOA deposits; 6) the further ascending fluid transports Fe, Cu, Au and S toward the surface where metal-oxides and metal-sulfides precipitate to form IOCG deposits. This model is globally applicable and explains the observed temporal and spatial relationship between magmatism and formation of IOA and IOCG deposits.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26931708','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26931708"><span>Equation of state and critical point behavior of hard-core double-Yukawa fluids.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montes, J; Robles, M; López de Haro, M</p> <p>2016-02-28</p> <p>A theoretical study on the equation of state and the critical point behavior of hard-core double-Yukawa fluids is presented. Thermodynamic perturbation theory, restricted to first order in the inverse temperature and having the hard-sphere fluid as the reference system, is used to derive a relatively simple analytical equation of state of hard-core multi-Yukawa fluids. Using such an equation of state, the compressibility factor and phase behavior of six representative hard-core double-Yukawa fluids are examined and compared with available simulation results. The effect of varying the parameters of the hard-core double-Yukawa intermolecular potential on the location of the critical point is also analyzed using different perspectives. The relevance of this analysis for fluids whose molecules interact with realistic potentials is also pointed out.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V23B2985D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V23B2985D"><span>Trace Elements and Oxygen Isotope Zoning of the Sidewinder Skarn</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Draper, C.; Gevedon, M. L.; Barnes, J.; Lackey, J. S.; Jiang, H.; Lee, C. T.</p> <p>2016-12-01</p> <p>Skarns of the Verde Antique Quarry and White Horse Mountain areas of the Sidewinder Range give insight into the paleohydrothermal systems operating in the California's Jurassic arc in the Southwestern Mojave Desert. Garnet from these skarns is iron rich: Xand= 55-100. Laser fluorination measurements show oxygen isotope (δ18O) compositions of garnet crystals and crystals domains have large ranges: -3.1‰ to +4.4‰ and -8.9‰ to +3.4‰, respectively. In general, the garnet cores have more negative δ18O values than rims, although oscillations are present. Negative values have been interpreted as influx of meteoric fluid and positive values as increased magmatic input. Here we report major and trace element concentrations for 17 core to rim Sidewinder garnet transects. REEs concentrations are low in all crystals, with total REE concentrations ranging from 0.710 ppm to 33.7 ppm, values that are lower than Cretaceous skarn garnets in the Sierra Nevada in the White Chief and Empire Mt skarns. Such low concentrations are likely due to the higher fraction of meteoric fluids during formation of the Sidewinder skarns. REE concentrations decrease from core to rim (REE core average=12.2ppm, REE rim average=7.21ppm). This is slightly more pronounced in the LREEs than in the HREEs (LaN/YbN core average= 10.9; rim average= 9.73, normalized to Chondrite). Xand tends to decrease core to rim in the Verde Antique skarn, whereas, Xand of the White Horse skarn does not correlate with distance from core. A large positive Eu anomaly (Eu/Eu* = 3-30) in garnet from both skarns suggests oxidizing fluid conditions. Oxygen isotope data from garnet in these same skarns show periods of time with increased proportion of magmatic derived fluids in the total fluid budget. However, there is no corresponding widespread increase in total REE concentrations. Other studies of skarns from the western Sierra Nevadan arc (White Chief and Empire Mountain) observe complete decoupling of d18O values and trace element compositions. Future modeling should consider modal abundance of fluid soluble minerals in cooling and altering plutons to probe the REE budget.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992GeoRL..19.1999B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992GeoRL..19.1999B"><span>Mean electromotive force generated by asymmetric fluid flow near the surface of earth's outer core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhattacharyya, Archana</p> <p>1992-10-01</p> <p>The phi component of the mean electromotive force, (ETF) generated by asymmetric flow of fluid just beneath the core-mantle boundary (CMB), is obtained using a geomagnetic field model. This analysis is based on the supposition that the axisymmetric part of fluid flow beneath the CMB is tangentially geostrophic and toroidal. For all the epochs studied, the computed phi component is stronger in the Southern Hemisphere than that in the Northern Hemisphere. Assuming a linear relationship between (ETF) and the azimuthally averaged magnetic field (AAMF), the only nonzero off-diagonal components of the pseudotensor relating ETF to AAMF, are estimated as functions of colatitude, and the physical implications of the results are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26507102','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26507102"><span>Characterisation of lubricin in synovial fluid from horses with osteoarthritis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Svala, E; Jin, C; Rüetschi, U; Ekman, S; Lindahl, A; Karlsson, N G; Skiöldebrand, E</p> <p>2017-01-01</p> <p>The glycoprotein lubricin contributes to the boundary lubrication of the articular cartilage surface. The early events of osteoarthritis involve the superficial layer where lubricin is synthesised. To characterise the glycosylation profile of lubricin in synovial fluid from horses with osteoarthritis and study secretion and degradation of lubricin in an in vitro inflammation cartilage model. In vitro study. Synovial fluid samples collected from horses with joints with normal articular cartilage and structural osteoarthritic lesions; with and without osteochondral fragments, were analysed for the lubricin glycosylation profiles. Articular cartilage explants were stimulated with or without interleukin-1β for 25 days. Media samples collected at 3-day intervals were analysed by quantitative proteomics, western blot and enzyme-linked immunosorbent assay. O-glycosylation profiles in synovial fluid revealed both Core 1 and 2 O-glycans, with Core 1 O-glycans predominating. Synovial fluid from normal joints (49.5 ± 1.9%) contained significantly lower amounts of monosialylated Core 1 O-glycans compared with joints with osteoarthritis (53.8 ± 7.8%, P = 0.03) or joints with osteochondral fragments (57.3 ± 8.8%, P = 0.001). Additionally, synovial fluid from normal joints (26.7 ± 6.7%) showed higher amounts of disialylated Core 1 O-glycan than from joints with osteochondral fragments (21.2 ± 4.9%, P = 0.03). A C-terminal proteolytic cleavage site in lubricin was found in synovial fluid from normal and osteochondral fragment joints and in media from interleukin-1β stimulated and unstimulated articular cartilage explants. This is the first demonstration of a change in the glycosylation profile of lubricin in synovial fluid from diseased equine joints compared with that from normal joints. We demonstrate an identical proteolytic cleavage site of lubricin both in vitro and in vivo. The reduced sialation of lubricin in synovial fluid from diseased joints may affect the boundary lubricating ability of the superficial layer of articular cartilage and could be one of the early events in the progression of osteoarthritis. © 2015 EVJ Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SoftX...7...88H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SoftX...7...88H"><span>LUMA: A many-core, Fluid-Structure Interaction solver based on the Lattice-Boltzmann Method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harwood, Adrian R. G.; O'Connor, Joseph; Sanchez Muñoz, Jonathan; Camps Santasmasas, Marta; Revell, Alistair J.</p> <p>2018-01-01</p> <p>The Lattice-Boltzmann Method at the University of Manchester (LUMA) project was commissioned to build a collaborative research environment in which researchers of all abilities can study fluid-structure interaction (FSI) problems in engineering applications from aerodynamics to medicine. It is built on the principles of accessibility, simplicity and flexibility. The LUMA software at the core of the project is a capable FSI solver with turbulence modelling and many-core scalability as well as a wealth of input/output and pre- and post-processing facilities. The software has been validated and several major releases benchmarked on supercomputing facilities internationally. The software architecture is modular and arranged logically using a minimal amount of object-orientation to maintain a simple and accessible software.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SolE....9..167G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SolE....9..167G"><span>Deeply subducted continental fragments - Part 1: Fracturing, dissolution-precipitation, and diffusion processes recorded by garnet textures of the central Sesia Zone (western Italian Alps)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giuntoli, Francesco; Lanari, Pierre; Engi, Martin</p> <p>2018-02-01</p> <p>Contiguous continental high-pressure terranes in orogens offer insight into deep recycling and transformation processes that occur in subduction zones. These remain poorly understood, and currently debated ideas need testing. The approach we chose is to investigate, in detail, the record in suitable rock samples that preserve textures and robust mineral assemblages that withstood overprinting during exhumation. We document complex garnet zoning in eclogitic mica schists from the Sesia Zone (western Italian Alps). These retain evidence of two orogenic cycles and provide detailed insight into resorption, growth, and diffusion processes induced by fluid pulses in high-pressure conditions. We analysed local textures and garnet compositional patterns, which turned out remarkably complex. By combining these with thermodynamic modelling, we could unravel and quantify repeated fluid-rock interaction processes. Garnet shows low-Ca porphyroclastic cores that were stable under (Permian) granulite facies conditions. The series of rims that surround these cores provide insight into the subsequent evolution: the first garnet rim that surrounds the pre-Alpine granulite facies core in one sample indicates that pre-Alpine amphibolite facies metamorphism followed the granulite facies event. In all samples documented, cores show lobate edges and preserve inner fractures, which are sealed by high-Ca garnet that reflects high-pressure Alpine conditions. These observations suggest that during early stages of subduction, before hydration of the granulites, brittle failure of garnet occurred, indicating high strain rates that may be due to seismic failure. Several Alpine rims show conspicuous textures indicative of interaction with hydrous fluid: (a) resorption-dominated textures produced lobate edges, at the expense of the outer part of the granulite core; (b) peninsulas and atoll garnet are the result of replacement reactions; and (c) spatially limited resorption and enhanced transport of elements due to the fluid phase are evident along brittle fractures and in their immediate proximity. Thermodynamic modelling shows that all of these Alpine rims formed under eclogite facies conditions. Structurally controlled samples allow these fluid-garnet interaction phenomena to be traced across a portion of the Sesia Zone, with a general decrease in fluid-garnet interaction observed towards the external, structurally lower parts of the terrane. Replacement of the Permian HT assemblages by hydrate-rich Alpine assemblages can reach nearly 100 % of the rock volume. Since we found no clear relationship between discrete deformation structures (e.g. shear zones) observed in the field and the fluid pulses that triggered the transformation to eclogite facies assemblages, we conclude that disperse fluid flow was responsible for the hydration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARK37001I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARK37001I"><span>Soft particles at fluid interfaces: wetting, structure, and rheology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Isa, Lucio</p> <p></p> <p>Most of our current knowledge concerning the behavior of colloidal particles at fluid interfaces is limited to model spherical, hard and uniform objects. Introducing additional complexity, in terms of shape, composition or surface chemistry or by introducing particle softness, opens up a vast range of possibilities to address new fundamental and applied questions in soft matter systems at fluid interfaces. In this talk I will focus on the role of particle softness, taking the case of core-shell microgels as a paradigmatic example. Microgels are highly swollen and cross-linked hydrogel particles that, in parallel with their practical applications, e.g. for emulsion stabilization and surface patterning, are increasingly used as model systems to capture fundamental properties of bulk materials. Most microgel particles develop a core-shell morphology during synthesis, with a more cross-linked core surrounded by a corona of loosely linked and dangling polymer chains. I will first discuss the difference between the wetting of a hard spherical colloid and a core-shell microgel at an oil-water interface, pinpointing the interplay between adsorption at the interface and particle deformation. I will then move on to discuss the interplay between particle morphology and the microstructure and rheological properties of the interface. In particular, I will demonstrate that synchronizing the compression of a core-shell microgel-laden fluid interface with the deposition of the interfacial monolayer makes it possible to transfer the 2D phase diagram of the particles onto a solid substrate, where different positions correspond to different values of the surface pressure and the specific area. Using atomic force microscopy, we analyzed the microstructure of the monolayer and discovered a phase transition between two crystalline phases with the same hexagonal symmetry, but with two different lattice constants. The two phases correspond to shell-shell or core-core inter-particle contacts, respectively, where with increasing surface pressure the former mechanically fail enabling the particle cores to come into contact. In the phase-transition region, clusters of particles in core-core contacts nucleate, melting the surrounding shell-shell crystal, until the whole monolayer moves into the second phase. We furthermore extended our analysis to measure the interfacial rheology of the monolayers as a function of the surface pressure using an interfacial microdisk rheometer; the interfaces always show a strong elastic response, with a dip in the elastic modulus in correspondence of the melting of the shell-shell phase, followed by a steep increase upon formation of a percolating network of the core-core contacts. The presented results highlight the complex interplay between the wetting and deformation of individual soft particles at fluid interfaces and the overall interface microstructure and mechanics. They show strong connections to fundamental studies on phase transitions in two-dimensional systems and pave the way for novel nanoscale surface patterning routes. The author acknowledges financial support from the Swiss National Science Foundation Grant PP00P2-144646/1.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MRE.....4k6310L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MRE.....4k6310L"><span>Fabrication of poly(o-anisidine) coated silica core-shell microspheres and their electrorheological response</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Chul Joo; Choi, Hyoung Jin</p> <p>2017-11-01</p> <p>In this work, silica/poly(o-anisidine) (POA) core-shell structured microspheres were synthesized by coating the silica core surface with POA with a help of a chemical grafting agent, N-[(3-trimethoxylsilyl)-propyl] aniline. The synthesized silica microspheres were then applied as a polymer/inorganic composite particle-based electrorheological (ER) fluid. The morphology of the silica/POA microspheres was examined by using both transmission electron microscopy and scanning electron microscopy, while their thermal properties and chemical structure were checked by thermogravimetric analysis and Fourier-transform infrared spectroscopy, respectively. The ER properties of the silica/POA particle-based ER fluid were examined by using a Couette-type rotational rheometer equipped with a high-voltage power supplier and analyzed by the Bingham model and modified Mason number. In order to obtain additional information about the electrical polarization properties, the dielectric spectra were measured by an LCR meter and fitted by using the Cole-Cole equation. Furthermore, suspension stability of the ER fluid was tested using Turbiscan.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PEPI..153..150B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PEPI..153..150B"><span>A laboratory model for solidification of Earth's core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bergman, Michael I.; Macleod-Silberstein, Marget; Haskel, Michael; Chandler, Benjamin; Akpan, Nsikan</p> <p>2005-11-01</p> <p>To better understand the influence of rotating convection in the outer core on the solidification of the inner core we have constructed a laboratory model for solidification of Earth's core. The model consists of a 15 cm radius hemispherical acrylic tank concentric with a 5 cm radius hemispherical aluminum heat exchanger that serves as the incipient inner core onto which we freeze ice from salt water. Long exposure photographs of neutrally buoyant particles in illuminated planes suggest reduction of flow parallel to the rotation axis. Thermistors in the tank near the heat exchanger show that in experiments with rotation the temperature near the pole is lower than near the equator, unlike for control experiments without rotation or with a polymer that increases the fluid viscosity. The photographs and thermistors suggest that our observation that ice grows faster near the pole than near the equator for experiments with rotation is a result of colder water not readily convecting away from the pole. Because of the reversal of the thermal gradient, we expect faster equatorial solidification in the Earth's core. Such anisotropy in solidification has been suggested as a cause of inner core elastic (and attenuation) anisotropy, though the plausibility of this suggestion will depend on the core Nusselt number and the slope of the liquidus, and the effects of post-solidification deformation. Previous experiments on hexagonal close-packed alloys such as sea ice and zinc-tin have shown that fluid flow in the melt can result in a solidification texture transverse to the solidification direction, with the texture depending on the nature of the flow. A comparison of the visualized flow and the texture of columnar ice crystals in thin sections from these experiments confirms flow-induced transverse textures. This suggests that the convective pattern at the base of the outer core is recorded in the texture of the inner core, and that outer core convection might contribute to the complexity in the seismically inferred pattern of anisotropy in the Earth's inner core.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012GeoRL..39.7302B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012GeoRL..39.7302B"><span>Scale dependence of in-situ permeability measurements in the Nankai accretionary prism: The role of fractures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boutt, David F.; Saffer, Demian; Doan, Mai-Linh; Lin, Weiren; Ito, Takatoshi; Kano, Yasuyuki; Flemings, Peter; McNeill, Lisa C.; Byrne, Timothy; Hayman, Nicholas W.; Moe, Kyaw Thu</p> <p>2012-04-01</p> <p>Modeling studies suggest that fluid permeability is an important control on the maintenance and distribution of pore fluid pressures at subduction zones generated through tectonic loading. Yet, to date, few data are available to constrain permeability of these materials, at appropriate scales. During IODP Expedition 319, downhole measurements of permeability within the uppermost accretionary wedge offshore SW Japan were made using a dual-packer device to isolate 1 m sections of borehole at a depth of 1500 m below sea floor. Analyses of pressure transients using numerical models suggest a range of in-situ fluid permeabilities (5E-15-9E-17 m2). These values are significantly higher than those measured on core samples (2E-19 m2). Borehole imagery and cores suggests the presence of multiple open fractures at this depth of measurement. These observations suggest that open permeable natural fractures at modest fracture densities could be important contributors to overall prism permeability structure at these scales.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54...37J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54...37J"><span>Simulation of non-Newtonian oil-water core annular flow through return bends</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Fan; Wang, Ke; Skote, Martin; Wong, Teck Neng; Duan, Fei</p> <p>2018-01-01</p> <p>The volume of fluid (VOF) model is used together with the continuum surface force (CSF) model to numerically simulate the non-Newtonian oil-water core annular flow across return bends. A comprehensive study is conducted to generate the profiles of pressure, velocity, volume fraction and wall shear stress for different oil properties, flow directions, and bend geometries. It is revealed that the oil core may adhere to the bend wall under certain operating conditions. Through the analysis of the total pressure gradient and fouling angle, suitable bend geometric parameters are identified for avoiding the risk of fouling.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8270N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8270N"><span>Numerical modelling of fluid-rock interactions: Lessons learnt from carbonate rocks diagenesis studies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nader, Fadi; Bachaud, Pierre; Michel, Anthony</p> <p>2015-04-01</p> <p>Quantitative assessment of fluid-rock interactions and their impact on carbonate host-rocks has recently become a very attractive research topic within academic and industrial realms. Today, a common operational workflow that aims at predicting the relevant diagenetic processes on the host rocks (i.e. fluid-rock interactions) consists of three main stages: i) constructing a conceptual diagenesis model including inferred preferential fluids pathways; ii) quantifying the resulted diagenetic phases (e.g. depositing cements, dissolved and recrystallized minerals); and iii) numerical modelling of diagenetic processes. Most of the concepts of diagenetic processes operate at the larger, basin-scale, however, the description of the diagenetic phases (products of such processes) and their association with the overall petrophysical evolution of sedimentary rocks remain at reservoir (and even outcrop/ well core) scale. Conceptual models of diagenetic processes are thereafter constructed based on studying surface-exposed rocks and well cores (e.g. petrography, geochemistry, fluid inclusions). We are able to quantify the diagenetic products with various evolving techniques and on varying scales (e.g. point-counting, 2D and 3D image analysis, XRD, micro-CT and pore network models). Geochemical modelling makes use of thermodynamic and kinetic rules as well as data-bases to simulate chemical reactions and fluid-rock interactions. This can be through a 0D model, whereby a certain process is tested (e.g. the likelihood of a certain chemical reaction to operate under specific conditions). Results relate to the fluids and mineral phases involved in the chemical reactions. They could be used as arguments to support or refute proposed outcomes of fluid-rock interactions. Coupling geochemical modelling with transport (reactive transport model; 1D, 2D and 3D) is another possibility, attractive as it provides forward simulations of diagenetic processes and resulting phases. This contribution is based on several studies that were undertaken on carbonate rocks diagenesis in some of the major reservoir rocks in the Middle East and outcrop analogues in Europe. Here, the main processes at hand are related to fracture-related dolomitization and carbonate dissolution. We would like to present the workflows we have followed and the questioning that resulted for a series of case studies. The way forward, seems evident as the integration of workflows and numerical modelling tools at different scales, bringing better constrains on the boundary data and less uncertainty.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......501S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......501S"><span>Design of Complex Systems to Achieve Passive Safety: Natural Circulation Cooling of Liquid Salt Pebble Bed Reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scarlat, Raluca Olga</p> <p></p> <p>This dissertation treats system design, modeling of transient system response, and characterization of individual phenomena and demonstrates a framework for integration of these three activities early in the design process of a complex engineered system. A system analysis framework for prioritization of experiments, modeling, and development of detailed design is proposed. Two fundamental topics in thermal-hydraulics are discussed, which illustrate the integration of modeling and experimentation with nuclear reactor design and safety analysis: thermal-hydraulic modeling of heat generating pebble bed cores, and scaled experiments for natural circulation heat removal with Boussinesq liquids. The case studies used in this dissertation are derived from the design and safety analysis of a pebble bed fluoride salt cooled high temperature nuclear reactor (PB-FHR), currently under development in the United States at the university and national laboratories level. In the context of the phenomena identification and ranking table (PIRT) methodology, new tools and approaches are proposed and demonstrated here, which are specifically relevant to technology in the early stages of development, and to analysis of passive safety features. A system decomposition approach is proposed. Definition of system functional requirements complements identification and compilation of the current knowledge base for the behavior of the system. Two new graphical tools are developed for ranking of phenomena importance: a phenomena ranking map, and a phenomena identification and ranking matrix (PIRM). The functional requirements established through this methodology were used for the design and optimization of the reactor core, and for the transient analysis and design of the passive natural circulation driven decay heat removal system for the PB-FHR. A numerical modeling approach for heat-generating porous media, with multi-dimensional fluid flow is presented. The application of this modeling approach to the PB-FHR annular pebble bed core cooled by fluoride salt mixtures generated a model that is called Pod. Pod. was used to show the resilience of the PB-FHR core to generation of hot spots or cold spots, due to the effect of buoyancy on the flow and temperature distribution in the packed bed. Pod. was used to investigate the PB-FHR response to ATWS transients. Based on the functional requirements for the core, Pod. was used to generate an optimized design of the flow distribution in the core. An analysis of natural circulation loops cooled by single-phase Boussinesq fluids is presented here, in the context of reactor design that relies on natural circulation decay heat removal, and design of scaled experiments. The scaling arguments are established for a transient natural circulation loop, for loops that have long fluid residence time, and negligible contribution of fluid inertia to the momentum equation. The design of integral effects tests for the loss of forced circulation (LOFC) for PB-FHR is discussed. The special case of natural circulation decay heat removal from a pebble bed reactor was analyzed. A way to define the Reynolds number in a multi-dimensional pebble bed was identified. The scaling methodology for replicating pebble bed friction losses using an electrically resistance heated annular pipe and a needle valve was developed. The thermophysical properties of liquid fluoride salts lead to design of systems with low flow velocities, and hence long fluid residence times. A comparison among liquid coolants for the performance of steady state natural circulation heat removal from a pebble bed was performed. Transient natural circulation experimental data with simulant fluids for fluoride salts is given here. The low flow velocity and the relatively high viscosity of the fluoride salts lead to low Reynolds number flows, and a low Reynolds number in conjunction with a sufficiently high coefficient of thermal expansion makes the system susceptible to local buoyancy effects Experiments indicate that slow exchange of stagnant fluid in static legs can play a significant role in the transient response of natural circulation loops. The effect of non-linear temperature profiles on the hot or cold legs or other segments of the flow loop, which may develop during transient scenarios, should be considered when modeling the performance of natural circulation loops. The data provided here can be used for validation of the application of thermal-hydraulic systems codes to the modeling of heat removal by natural circulation with liquid fluoride salts and its simulant fluids.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMDI33B0414T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMDI33B0414T"><span>Observation and excitation of magnetohydrodynamic waves in numerical models of Earth's core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Teed, R.; Hori, K.; Tobias, S.; Jones, C. A.</p> <p>2017-12-01</p> <p>Several types of magnetohydrodynamic waves are theorised to operate in Earth's outer core but their detection is limited by the inability to probe the fluid core directly. Secular variation data and periodic changes in Earth's length-of-day provide evidence for the possible existence of waves. Numerical simulations of core dynamics enable us to search directly for waves and determine their properties. With this information it is possible to consider whether they can be the origin of features observed in observational data. We focus on two types of wave identified in our numerical experiments: i) torsional waves and ii) slow magnetic Rossby waves. Our models display periodic, Earth-like torsional waves that travel outwards from the tangent cylinder circumscribing the inner core. We discuss the properties of these waves and their similarites to observational data. Excitation is via a matching of the Alfvén frequency with that of small modes of convection focused at the tangent cylinder. The slow magnetic Rossby waves observed in our simulations show that these waves may account for some geomagnetic westward drifts observed at mid-latitudes. We present analysis showing excitation of waves by the convective instability and we discuss how the detection of these waves could also provide an estimate of the strength of the toroidal component of the magnetic field within the planetary fluid core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhFl...27h2102F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhFl...27h2102F"><span>Flow of two immiscible fluids in a periodically constricted tube: Transitions to stratified, segmented, churn, spray, or segregated flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fraggedakis, D.; Kouris, Ch.; Dimakopoulos, Y.; Tsamopoulos, J.</p> <p>2015-08-01</p> <p>We study the flow of two immiscible, Newtonian fluids in a periodically constricted tube driven by a constant pressure gradient. Our volume-of-fluid algorithm is used to solve the governing equations. First, the code is validated by comparing its predictions to previously reported results for stratified and pulsing flow. Then, it is used to capture accurately all the significant topological changes that take place. Initially, the fluids have a core-annular arrangement, which is found to either remain the same or change to a different arrangement depending on the fluid properties, the pressure driving the flow, or the flow geometry. The flow-patterns that appear are the core-annular, segmented, churn, spray, and segregated flow. The predicted scalings near pinching of the core fluid concur with similarity predictions and earlier numerical results [I. Cohen et al., "Two fluid drop snap-off problem: Experiments and theory," Phys. Rev. Lett. 83, 1147-1150 (1999)]. Flow-pattern maps are constructed in terms of the Reynolds and Weber numbers. Our result provides deeper insights into the mechanism of the pattern transitions and is in agreement with previous studies on core-annular flow [Ch. Kouris and J. Tsamopoulos, "Core-annular flow in a periodically constricted circular tube, I. Steady state, linear stability and energy analysis," J. Fluid Mech. 432, 31-68 (2001) and Ch. Kouris et al., "Comparison of spectral and finite element methods applied to the study of interfacial instabilities of the core-annular flow in an undulating tube," Int. J. Numer. Methods Fluids 39(1), 41-73 (2002)], segmented flow [E. Lac and J. D. Sherwood, "Motion of a drop along the centreline of a capillary in a pressure-driven flow," J. Fluid Mech. 640, 27-54 (2009)], and churn flow [R. Y. Bai et al., "Lubricated pipelining—Stability of core annular-flow. 5. Experiments and comparison with theory," J. Fluid Mech. 240, 97-132 (1992)].</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JChPh.112.3245M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JChPh.112.3245M"><span>Hard sphere perturbation theory of dense fluids with singular perturbation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mon, K. K.</p> <p>2000-02-01</p> <p>Hard sphere perturbation theories (HSPT) played a significant role in the fundamental understanding of fluids and continues to be a popular method in a wide range of applications. The possibility of difficulty with singular perturbation for some classical soft core model fluids appears to have been overlooked or ignored in the literature. We address this issue in this short note and show by analysis that a region of phase space has been neglected in the standard application of HSPT involving singular perturbation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070032708','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070032708"><span>Numerical Simulations of Single Flow Element in a Nuclear Thermal Thrust Chamber</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cheng, Gary; Ito, Yasushi; Ross, Doug; Chen, Yen-Sen; Wang, Ten-See</p> <p>2007-01-01</p> <p>The objective of this effort is to develop an efficient and accurate computational methodology to predict both detailed and global thermo-fluid environments of a single now element in a hypothetical solid-core nuclear thermal thrust chamber assembly, Several numerical and multi-physics thermo-fluid models, such as chemical reactions, turbulence, conjugate heat transfer, porosity, and power generation, were incorporated into an unstructured-grid, pressure-based computational fluid dynamics solver. The numerical simulations of a single now element provide a detailed thermo-fluid environment for thermal stress estimation and insight for possible occurrence of mid-section corrosion. In addition, detailed conjugate heat transfer simulations were employed to develop the porosity models for efficient pressure drop and thermal load calculations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017046','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017046"><span>Determination of subsurface fluid contents at a crude-oil spill site</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hess, K.M.; Herkelrath, W.N.; Essaid, H.I.</p> <p>1992-01-01</p> <p>Measurement of the fluid-content distribution at sites contaminated by immiscible fluids, including crude oil, is needed to better understand the movement of these fluids in the subsurface and to provide data to calibrate and verify numerical models and geophysical methods. A laboratory method was used to quantify the fluid contents of 146 core sections retrieved from boreholes aligned along a 120-m longitudinal transect at a crude-oil spill site near Bemidji, Minnesota, U.S.A. The 47-mm-diameter, minimally disturbed cores spanned a 4-m vertical interval contaminated by oil. Cores were frozen on site in a dry ice-alcohol bath to prevent redistribution and loss of fluids while sectioning the cores. We gravimetrically determined oil and water contents using a two-step method: (1) samples were slurried and the oil was removed by absorption onto strips of hydrophobic porous polyethylene (PPE); and (2) the samples were oven-dried to remove the water. The resulting data show sharp vertical gradients in the water and oil contents and a clearly defined oil body. The subsurface distribution is complex and appears to be influenced by sediment heterogeneities and water-table fluctuations. The center of the oil body has depressed the water-saturated zone boundary, and the oil is migrating laterally within the capillary fringe. The oil contents are as high as 0.3 cm3 cm-3, which indicates that oil is probably still mobile 10 years after the spill occurred. The thickness of oil measured in wells suggests that accumulated thickness in wells is a poor indicator of the actual distribution of oil in the subsurface. Several possible sources of error are identified with the field and laboratory methods. An error analysis indicates that adsorption of water and sediment into the PPE adds as much as 4% to the measured oil masses and that uncertainties in the calculated sample volume and the assumed oil density introduce an additional ??3% error when the masses are converted to fluid contents.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22105916-experimental-code-simulation-station-blackout-scenario-apr1400-test-facility-atlas-mars-code','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22105916-experimental-code-simulation-station-blackout-scenario-apr1400-test-facility-atlas-mars-code"><span>Experimental and code simulation of a station blackout scenario for APR1400 with test facility ATLAS and MARS code</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yu, X. G.; Kim, Y. S.; Choi, K. Y.</p> <p>2012-07-01</p> <p>A SBO (station blackout) experiment named SBO-01 was performed at full-pressure IET (Integral Effect Test) facility ATLAS (Advanced Test Loop for Accident Simulation) which is scaled down from the APR1400 (Advanced Power Reactor 1400 MWe). In this study, the transient of SBO-01 is discussed and is subdivided into three phases: the SG fluid loss phase, the RCS fluid loss phase, and the core coolant depletion and core heatup phase. In addition, the typical phenomena in SBO-01 test - SG dryout, natural circulation, core coolant boiling, the PRZ full, core heat-up - are identified. Furthermore, the SBO-01 test is reproduced bymore » the MARS code calculation with the ATLAS model which represents the ATLAS test facility. The experimental and calculated transients are then compared and discussed. The comparison reveals there was malfunction of equipments: the SG leakage through SG MSSV and the measurement error of loop flow meter. As the ATLAS model is validated against the experimental results, it can be further employed to investigate the other possible SBO scenarios and to study the scaling distortions in the ATLAS. (authors)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16364351','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16364351"><span>Porous structure and fluid partitioning in polyethylene cores from 3D X-ray microtomographic imaging.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prodanović, M; Lindquist, W B; Seright, R S</p> <p>2006-06-01</p> <p>Using oil-wet polyethylene core models, we present the development of robust throat finding techniques for the extraction, from X-ray microtomographic images, of a pore network description of porous media having porosity up to 50%. Measurements of volume, surface area, shape factor, and principal diameters are extracted for pores and area, shape factor and principal diameters for throats. We also present results on the partitioning of wetting and non-wetting phases in the pore space at fixed volume increments of the injected fluid during a complete cycle of drainage and imbibition. We compare these results with fixed fractional flow injection, where wetting and non-wetting phase are simultaneously injected at fixed volume ratio. Finally we demonstrate the ability to differentiate three fluid phases (oil, water, air) in the pore space.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003GeoJI.155..111F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003GeoJI.155..111F"><span>Fault compaction and overpressured faults: results from a 3-D model of a ductile fault zone</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fitzenz, D. D.; Miller, S. A.</p> <p>2003-10-01</p> <p>A model of a ductile fault zone is incorporated into a forward 3-D earthquake model to better constrain fault-zone hydraulics. The conceptual framework of the model fault zone was chosen such that two distinct parts are recognized. The fault core, characterized by a relatively low permeability, is composed of a coseismic fault surface embedded in a visco-elastic volume that can creep and compact. The fault core is surrounded by, and mostly sealed from, a high permeability damaged zone. The model fault properties correspond explicitly to those of the coseismic fault core. Porosity and pore pressure evolve to account for the viscous compaction of the fault core, while stresses evolve in response to the applied tectonic loading and to shear creep of the fault itself. A small diffusive leakage is allowed in and out of the fault zone. Coseismically, porosity is created to account for frictional dilatancy. We show in the case of a 3-D fault model with no in-plane flow and constant fluid compressibility, pore pressures do not drop to hydrostatic levels after a seismic rupture, leading to an overpressured weak fault. Since pore pressure plays a key role in the fault behaviour, we investigate coseismic hydraulic property changes. In the full 3-D model, pore pressures vary instantaneously by the poroelastic effect during the propagation of the rupture. Once the stress state stabilizes, pore pressures are incrementally redistributed in the failed patch. We show that the significant effect of pressure-dependent fluid compressibility in the no in-plane flow case becomes a secondary effect when the other spatial dimensions are considered because in-plane flow with a near-lithostatically pressured neighbourhood equilibrates at a pressure much higher than hydrostatic levels, forming persistent high-pressure fluid compartments. If the observed faults are not all overpressured and weak, other mechanisms, not included in this model, must be at work in nature, which need to be investigated. Significant leakage perpendicular to the fault strike (in the case of a young fault), or cracks hydraulically linking the fault core to the damaged zone (for a mature fault) are probable mechanisms for keeping the faults strong and might play a significant role in modulating fault pore pressures. Therefore, fault-normal hydraulic properties of fault zones should be a future focus of field and numerical experiments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H23K..03V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H23K..03V"><span>Integrated Modeling and Experiments to Characterize Coupled Thermo-hydro-geomechanical-chemical processes in Hydraulic Fracturing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viswanathan, H. S.; Carey, J. W.; Karra, S.; Porter, M. L.; Rougier, E.; Kang, Q.; Makedonska, N.; Hyman, J.; Jimenez Martinez, J.; Frash, L.; Chen, L.</p> <p>2015-12-01</p> <p>Hydraulic fracturing phenomena involve fluid-solid interactions embedded within coupled thermo-hydro-mechanical-chemical (THMC) processes over scales from microns to tens of meters. Feedbacks between processes result in complex dynamics that must be unraveled if one is to predict and, in the case of unconventional resources, facilitate fracture propagation, fluid flow, and interfacial transport processes. The proposed work is part of a broader class of complex systems involving coupled fluid flow and fractures that are critical to subsurface energy issues, such as shale oil, geothermal, carbon sequestration, and nuclear waste disposal. We use unique LANL microfluidic and triaxial core flood experiments integrated with state-of-the-art numerical simulation to reveal the fundamental dynamics of fracture-fluid interactions to characterize the key coupled processes that impact hydrocarbon production. We are also comparing CO2-based fracturing and aqueous fluids to enhance production, greatly reduce waste water, while simultaneously sequestering CO2. We will show pore, core and reservoir scale simulations/experiments that investigate the contolling mechanisms that control hydrocarbon production.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992AIPC..246..998J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992AIPC..246..998J"><span>Numerical prediction of an axisymmetric turbulent mixing layer using two turbulence models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, Richard W.</p> <p>1992-01-01</p> <p>Nuclear power, once considered and then rejected (in the U. S.) for application to space vehicle propulsion, is being reconsidered for powering space rockets, especially for interplanetary travel. The gas core reactor, a high risk, high payoff nuclear engine concept, is one that was considered in the 1960s and 70s. As envisioned then, the gas core reactor would consist of a heavy, slow moving core of fissioning uranium vapor surrounded by a fast moving outer stream of hydrogen propellant. Satisfactory operation of such a configuration would require stable nuclear reaction kinetics to occur simultaneously with a stable, coflowing, probably turbulent fluid system having a dense inner stream and a light outer stream. The present study examines the behavior of two turbulence models in numerically simulating an idealized version of the above coflowing fluid system. The two models are the standard k˜ɛ model and a thin shear algebraic stress model (ASM). The idealized flow system can be described as an axisymmetric mixing layer of constant density. Predictions for the radial distribution of the mean streamwise velocity and shear stress for several axial stations are compared with experiment. Results for the k˜ɛe predictions are broadly satisfactory while those for the ASM are distinctly poorer.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.G41B1025D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.G41B1025D"><span>Core dynamics and the nutations of the Earth.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dehant, V. M. A.; Laguerre, R.; Rekier, J.; Rivoldini, A.; Trinh, A.; Triana, A. S.; Van Hoolst, T.; Zhu, P.</p> <p>2016-12-01</p> <p>We here present an overview of the recent activities within the project RotaNut - Rotation and Nutation of a Wobbly Earth, an ERC Advanced Grant funding from the European Research Council. We have recomputed the Basic Earth Parameters from recent VLBI series and we interpret them in terms of physics of the Earth's deep interior. This includes updates of the nutational constraints on Earth's internal magnetic field and inner core viscosity, as well as of the coupling constants at the core-mantle boundary (CMB) and inner core boundary ICB. We have explored on simplified Earth models the interactions between rotational and gravito-inertial modes. With the help of numerical simulations, we have also addressed the coupling between the global rotation and the inertial waves in the fluid core through parametric instabilities. Special interests have been given to the influence of the inner core onto the stability properties of the liquid core and the large scale formation in the turbulent flow through inverse cascade of energy. The role of precession and nutation forcing for the liquid core is characterized as well as the interaction between the Free Core Nutation (in the fluid core community called the tilt-over mode) and the inertial waves. This research represents the first steps in the project RotaNut financed by the European Research Council under ERC Advanced Grant 670874 for 2015-2020.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMOS23B2010L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMOS23B2010L"><span>3D Chirp Sonar Images on Fluid Migration Pathways and Their Implications on Seafloor Stability East of the Fangliao Submarine Canyon Offshore SW Taiwan</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Y. W.; Liu, C. S.; Su, C. C.; Hsu, H. H.; Chen, Y. H.</p> <p>2015-12-01</p> <p>This study utilizes both chirp sonar images and coring results to investigate the unstable seafloor strata east of the Fangliao Submarine Canyon offshore southwestern Taiwan. We have constructed 3D chirp sonar images from a densely surveyed block to trace the attitude of an acoustic transparent layer and features caused by fluid activities. Based on the distribution of this transparent layer and fluid-related features, we suggest that this transparent layer forms a pathway for fluid migration which induces fluid-related characters such as acoustic blanking and fluid chimneys in the 3D chirp sonar images. Cored seafloor samples are used in this study to investigate the sediment compositions. The 210Pb activity profiles of the cores show oscillating and unsteady values at about 20~25 cm from core top. The bulk densities of the core samples in the same section (about 20~25 cm from core top) give values lower than those at deeper parts of the cores. These results indicate that the water content is much higher in the shallow sediments than in the deeper strata. From core sample analyses, we deduce that the local sediments are disturbed by liquefaction. From the analyses of 3D chirp sonar images and core data, we suggest that the seafloor east of the Fangliao Submarine Canyon is in an unstable condition, if disturbed by earthquakes, submarine landslides and gravity flows could be easily triggered and cause some geohazards, like breaking submarine cables during the 2006 Pingtung earthquake event.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987snps.symp..407H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987snps.symp..407H"><span>Transient thermohydraulic heat pipe modeling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hall, Michael L.; Doster, Joseph M.</p> <p></p> <p>Many space based reactor designs employ heat pipes as a means of conveying heat. In these designs, thermal radiation is the principle means for rejecting waste heat from the reactor system, making it desirable to operate at high temperatures. Lithium is generally the working fluid of choice as it undergoes a liquid-vapor transformation at the preferred operating temperature. The nature of remote startup, restart, and reaction to threats necessitates an accurate, detailed transient model of the heat pipe operation. A model is outlined of the vapor core region of the heat pipe which is part of a large model of the entire heat pipe thermal response. The vapor core is modeled using the area averaged Navier-Stokes equations in one dimension, which take into account the effects of mass, energy and momentum transfer. The core model is single phase (gaseous), but contains two components: lithium gas and a noncondensible vapor. The vapor core model consists of the continuity equations for the mixture and noncondensible, as well as mixture equations for internal energy and momentum.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1513800L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1513800L"><span>Development of fluid overpressures in crustal faults and implications for earthquakes mechanics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leclère, Henri; Cappa, Frédéric; Faulkner, Daniel; Armitage, Peter; Blake, Oshaine; Fabbri, Olivier</p> <p>2013-04-01</p> <p>The development and maintenance of fluid overpressures strongly influence the mechanical behavior of the crust and especially crustal fault zones. The mechanisms allowing fluid pressure build-up are still open questions, and their influence on tectonic and fault weakening processes remain unclear. The determination of the hydraulic and mechanical properties of crustal fault zone elements is a key aspect to improve our understanding of the fluid-tectonic interactions and more particularly the role of fluids in fault mechanics and earthquake triggering. Here we address this question combining geological observations, laboratory experiments and hydromechanical models of an active crustal fault-zone in the Ubaye-Argentera area (southeastern France). Previous studies showed that the fluids located in the fault zone developed overpressures between 7 and 26 MPa, that triggered intense seismic swarms (i.e. 16,000 events in 2003-2004) (Jenatton et al., 2007; Daniel et al., 2011; Leclère et al., 2012). The fault-zone studied here is located in the Argentera external crystalline massif and is connected to regional NW-SE steeply-dipping dextral strike-slip faults with an offset of several kilometers. The fault zone cuts through migmatitic gneisses composed of quartz, K-feldspar, plagioclase, biotite and minor muscovite. It exposes several anastomosed core zones surrounded by damage zones with a pluri-decametric total width. The core zones are made up of centimetric to pluridecimetric phyllosilicate-rich gouge layers while the damage zones are composed of pluri-metric phyllonitic rock derived from mylonite. The permeability and elastic moduli of the host rock, damage zone and fault core were measured from plugs with a diameter of 20 mm and lengths between 26 to 51 mm, using a high-pressure hydrostatic fluid-flow apparatus. Measurements were made with confining pressures ranging from 30 to 210 MPa and using argon pore fluid pressure of 20 MPa. Data show a variation of the permeability values of one order of magnitude between host rock and fault zone and a decrease of 50% of the elastic properties between host rock and core zone. The heterogeneity of properties is related to the development of different microstructures across the fault-zone during the tectonic history. From these physical property values and the fault zone architecture, we analyze the effects of sudden mechanical loading on the development of fluid overpressures in fault-zone. To do this, we use a series of 1-D hydromechanical numerical models to show that sudden mechanical stress increase is a viable mechanism for fluid overpressuring in fault-zone with spatially-varying elastic and hydraulic properties. Based on these results, we discuss the implications for earthquake triggering.on crustal-scale faults.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AN....326..905W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AN....326..905W"><span>Convective radiation fluid-dynamics: formation and early evolution of ultra low-mass objects</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wuchterl, G.</p> <p>2005-12-01</p> <p>The formation process of ultra low-mass objects is some kind of extension of the star formation process. The physical changes towards lower mass are discussed by investigating the collapse of cloud cores that are modelled as Bonnor-Ebert spheres. Their collapse is followed by solving the equations of fluid dynamics with radiation and a model of time-dependent convection that has been calibrated to the Sun. For a sequence of cloud-cores with 1 to 0.01 solar masses, evolutionary tracks and isochrones are shown in the mass-radius diagram, the Hertzsprung-Russel diagram and the effective temperature-surface gravity or Kiel diagram. The collapse and the early hydrostatic evolution to ages of few Ma are briefly discussed and compared to observations of objects in Upper Scorpius and the low-mass components of GG Tau.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CeMDA.129..449B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CeMDA.129..449B"><span>Rotation of a rigid satellite with a fluid component: a new light onto Titan's obliquity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boué, Gwenaël; Rambaux, Nicolas; Richard, Andy</p> <p>2017-12-01</p> <p>We revisit the rotation dynamics of a rigid satellite with either a liquid core or a global subsurface ocean. In both problems, the flow of the fluid component is assumed inviscid. The study of a hollow satellite with a liquid core is based on the Poincaré-Hough model which provides exact equations of motion. We introduce an approximation when the ellipticity of the cavity is low. This simplification allows to model both types of satellite in the same manner. The analysis of their rotation is done in a non-canonical Hamiltonian formalism closely related to Poincaré's "forme nouvelle des équations de la mécanique". In the case of a satellite with a global ocean, we obtain a seven-degree-of-freedom system. Six of them account for the motion of the two rigid components, and the last one is associated with the fluid layer. We apply our model to Titan for which the origin of the obliquity is still a debated question. We show that the observed value is compatible with Titan slightly departing from the hydrostatic equilibrium and being in a Cassini equilibrium state.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018TePhL..44..217A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018TePhL..44..217A"><span>The Effect of the Air-Delivery Method on Parameters of the Precessing Vortex Core in a Hydrodynamic Vortex Chamber</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alekseenko, S. V.; Shtork, S. I.; Yusupov, R. R.</p> <p>2018-03-01</p> <p>The effect of the method of gas-phase injection into a swirled fluid flow on parameters of a precessing vortex core is studied experimentally. Conditions of the appearance of the vortex-core precession effect were modeled in a hydrodynamic sudden expansion vortex chamber. The dependences of the vortexcore precession frequency, flow-pulsation level, and full pressure differential in the vortex chamber on the consumption gas content in the flow have been obtained. The results of measurements permit one to determine optimum conditions for the most effective control of vortex-core precession.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMMR14A..06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMMR14A..06K"><span>Digital Rock Simulation of Flow in Carbonate Samples</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klemin, D.; Andersen, M.</p> <p>2014-12-01</p> <p>Reservoir engineering has becomes more complex to deal with current challenges, so core analysts must understand and model pore geometries and fluid behaviors at pores scales more rapidly and realistically. We introduce an industry-unique direct hydrodynamic pore flow simulator that operates on pore geometries from digital rock models obtained using microCT or 3D scanning electron microscope (SEM) images. The PVT and rheological models used in the simulator represent real reservoir fluids. Fluid-solid interactions are introduced using distributed micro-scale wetting properties. The simulator uses density functional approach applied for hydrodynamics of complex systems. This talk covers selected applications of the simulator. We performed microCT scanning of six different carbonate rock samples from homogeneous limestones to vuggy carbonates. From these, we constructed digital rock models representing pore geometries for the simulator. We simulated nonreactive tracer flow in all six digital models using a digital fluid description that included a passive tracer solution. During the simulation, we evaluated the composition of the effluent. Results of tracer flow simulations corresponded well with experimental data of nonreactive tracer floods for the same carbonate rock types. This simulation data of the non-reactive tracer flow can be used to calculate the volume of the rock accessible by the fluid, which can be further used to predict response of a porous medium to a reactive fluid. The described digital core analysis workflow provides a basis for a wide variety of activities, including input to design acidizing jobs and evaluating treatment efficiency and EOR economics. Digital rock multiphase flow simulations of a scanned carbonate rock evaluated the effect of wettability on flow properties. Various wetting properties were tested: slightly oil wet, slightly water wet, and water wet. Steady-state relative permeability simulations yielded curves for all three ranges of wetting properties. The wetting variation affected phase mobility and residual phase saturations for primary oil flood and floods with varying ratios of oil and water.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyA..493..342Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyA..493..342Z"><span>Thermodynamic properties of diamond and wurtzite model fluids from computer simulation and thermodynamic perturbation theory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, S.; Solana, J. R.</p> <p>2018-03-01</p> <p>Monte Carlo NVT simulations have been performed to obtain the thermodynamic and structural properties and perturbation coefficients up to third order in the inverse temperature expansion of the Helmholtz free energy of fluids with potential models proposed in the literature for diamond and wurtzite lattices. These data are used to analyze performance of a coupling parameter series expansion (CPSE). The main findings are summarized as follows, (1) The CPSE provides accurate predictions of the first three coefficient in the inverse temperature expansion of Helmholtz free energy for the potential models considered and the thermodynamic properties of these fluids are predicted more accurately when the CPSE is truncated at second or third order. (2) The Barker-Henderson (BH) recipe is appropriate for determining the effective hard sphere diameter for strongly repulsive potential cores, but its performance worsens with increasing the softness of the potential core. (3) For some thermodynamic properties the first-order CPSE works better for the diamond potential, whose tail is dominated by repulsive interactions, than for the potential, whose tail is dominated by attractive interactions. However, the first-order CPSE provides unsatisfactory results for the excess internal energy and constant-volume excess heat capacity for the two potential models.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012epsc.conf..840R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012epsc.conf..840R"><span>Anelastic tidal dissipation in multi-layer planets</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Remus, F.; Mathis, S.; Zahn, J.-P.; Lainey, V.</p> <p>2012-09-01</p> <p>Earth-like planets have anelastic mantles, whereas giant planets may have anelastic cores. As for the fluid parts of a body, the tidal dissipation of such solid regions, gravitationally perturbed by a companion body, highly depends on its internal friction, and thus on its internal structure. Therefore, modelling this kind of interaction presents a high interest to provide constraints on planets interiors, whose properties are still quite uncertain. Here, we examine the equilibrium tide in the solid part of a planet, taking into account the presence of a fluid envelope. We derive the different Love numbers that describe its deformation and discuss the dependence of the quality factor Q on the chosen anelastic model and the size of the core. Taking plausible values for the anelastic parameters, and discussing the frequency-dependence of the solid dissipation, we show how this mechanism may compete with the dissipation in fluid layers, when applied to Jupiter- and Saturn-like planets. We also discuss the case of the icy giants Uranus and Neptune. Finally, we present the way to implement the results in the equations that describe the dynamical evolution of planetary systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10576731','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10576731"><span>Core rotational dynamics and geological events</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Greff-Lefftz; Legros</p> <p>1999-11-26</p> <p>A study of Earth's fluid core oscillations induced by lunar-solar tidal forces, together with tidal secular deceleration of Earth's axial rotation, shows that the rotational eigenfrequency of the fluid core and some solar tidal waves were in resonance around 3.0 x 10(9), 1.8 x 10(9), and 3 x 10(8) years ago. The associated viscomagnetic frictional power at the core boundaries may be converted into heat and would destabilize the D" thermal layer, leading to the generation of deep-mantle plumes, and would also increase the temperature at the fluid core boundaries, perturbing the core dynamo process. Such phenomena could account for large-scale episodes of continental crust formation, the generation of flood basalts, and abrupt changes in geomagnetic reversal frequency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/862939','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/862939"><span>Nuclear reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Pennell, William E.; Rowan, William J.</p> <p>1977-01-01</p> <p>A nuclear reactor in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assmblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters and the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters and the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........34O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........34O"><span>Spin Imbalanced Quasi-Two-Dimensional Fermi Gases</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ong, Willie C.</p> <p></p> <p>Spin-imbalanced Fermi gases serve as a testbed for fundamental notions and are efficient table-top emulators of a variety of quantum matter ranging from neutron stars, the quark-gluon plasma, to high critical temperature superconductors. A macroscopic quantum phenomenon which occurs in spin-imbalanced Fermi gases is that of phase separation; in three dimensions, a spin-balanced, fully-paired superfluid core is surrounded by an imbalanced normal-fluid shell, followed by a fully polarized shell. In one dimension, the behavior is reversed; a balanced phase appears outside a spin-imbalanced core. This thesis details the first density profile measurements and studies on spin-imbalanced quasi-2D Fermi gases, accomplished with high-resolution, rapid sequential spin-imaging. The measured cloud radii and central densities are in disagreement with mean-field Bardeen-Cooper-Schrieffer theory for a 2D system. Data for normal-fluid mixtures are well fit by a simple 2D polaron model of the free energy. Not predicted by the model is an observed phase transition to a spin-balanced central core above a critical polarisation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1407283-impact-dynamical-core-direct-simulation-tropical-cyclones-high-resolution-global-model','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1407283-impact-dynamical-core-direct-simulation-tropical-cyclones-high-resolution-global-model"><span>Impact of the dynamical core on the direct simulation of tropical cyclones in a high-resolution global model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Reed, K. A.; Bacmeister, J. T.; Rosenbloom, N. A.; ...</p> <p>2015-05-13</p> <p>Our paper examines the impact of the dynamical core on the simulation of tropical cyclone (TC) frequency, distribution, and intensity. The dynamical core, the central fluid flow component of any general circulation model (GCM), is often overlooked in the analysis of a model's ability to simulate TCs compared to the impact of more commonly documented components (e.g., physical parameterizations). The Community Atmosphere Model version 5 is configured with multiple dynamics packages. This analysis demonstrates that the dynamical core has a significant impact on storm intensity and frequency, even in the presence of similar large-scale environments. In particular, the spectral elementmore » core produces stronger TCs and more hurricanes than the finite-volume core using very similar parameterization packages despite the latter having a slightly more favorable TC environment. Furthermore, these results suggest that more detailed investigations into the impact of the GCM dynamical core on TC climatology are needed to fully understand these uncertainties. Key Points The impact of the GCM dynamical core is often overlooked in TC assessments The CAM5 dynamical core has a significant impact on TC frequency and intensity A larger effort is needed to better understand this uncertainty« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22560346','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22560346"><span>Theoretical models for supercritical fluid extraction.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Zhen; Shi, Xiao-Han; Jiang, Wei-Juan</p> <p>2012-08-10</p> <p>For the proper design of supercritical fluid extraction processes, it is essential to have a sound knowledge of the mass transfer mechanism of the extraction process and the appropriate mathematical representation. In this paper, the advances and applications of kinetic models for describing supercritical fluid extraction from various solid matrices have been presented. The theoretical models overviewed here include the hot ball diffusion, broken and intact cell, shrinking core and some relatively simple models. Mathematical representations of these models have been in detail interpreted as well as their assumptions, parameter identifications and application examples. Extraction process of the analyte solute from the solid matrix by means of supercritical fluid includes the dissolution of the analyte from the solid, the analyte diffusion in the matrix and its transport to the bulk supercritical fluid. Mechanisms involved in a mass transfer model are discussed in terms of external mass transfer resistance, internal mass transfer resistance, solute-solid interactions and axial dispersion. The correlations of the external mass transfer coefficient and axial dispersion coefficient with certain dimensionless numbers are also discussed. Among these models, the broken and intact cell model seems to be the most relevant mathematical model as it is able to provide realistic description of the plant material structure for better understanding the mass-transfer kinetics and thus it has been widely employed for modeling supercritical fluid extraction of natural matters. Copyright © 2012 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1393290-development-calibration-reactive-transport-model-carbonate-reservoir-porosity-permeability-changes-based-co2-core-flood-experiments','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1393290-development-calibration-reactive-transport-model-carbonate-reservoir-porosity-permeability-changes-based-co2-core-flood-experiments"><span>Development and calibration of a reactive transport model for carbonate reservoir porosity and permeability changes based on CO 2 core-flood experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Smith, Megan M.; Hao, Y.; Carroll, S. A.</p> <p>2017-01-02</p> <p>Here, beneficial pore space and permeability enhancements are likely to occur as CO 2-charged fluids partially dissolve carbonate minerals in carbonate reservoir formations used for geologic CO 2 storage. The ability to forecast the extent and impact of changes in porosity and permeability will aid geologic CO 2 storage operations and lower uncertainty in estimates of long-term storage capacity. Our work is directed toward developing calibrated reactive transport models that more accurately capture the chemical impacts of CO 2-fluid-rock interactions and their effects on porosity and permeability by matching pressure, fluid chemistry, and dissolution features that developed as a resultmore » of reaction with CO 2-acidified brines at representative reservoir conditions. We present new results from experiments conducted on seven core samples from the Arbuckle Dolostone (near Wellington, Kansas, USA, recovered as part of the South-Central Kansas CO 2 Demonstration). Cores were obtained from both target reservoir and lower-permeability baffle zones, and together these samples span over 3–4 orders of magnitude of permeability according to downhole measurements. Core samples were nondestructively imaged by X-ray computed tomography and the resulting characterization data were mapped onto a continuum domain to further develop a reactive transport model for a range of mineral and physical heterogeneity. We combine these new results with those from previous experimental studies to more fully constrain the governing equations used in reactive transport models to better estimate the transition of enhanced oil recovery operations to long-term geology CO 2 storage. Calcite and dolomite kinetic rate constants (mol m –2 s –1) derived by fitting the results from core-flood experiments range from k calcite,25C = 10 –6.8 to 10 –4.6, and k dolomite,25C = 10 –7.5 to 10 –5.3. The power law-based porosity-permeability relationship is sensitive to the overall pore space heterogeneity of each core. Stable dissolution fronts observed in the more homogeneous dolostones could be accurately simulated using an exponential value of n = 3. Furthermore, unstable dissolution fronts consisting of preferential flowpaths could be simulated using an exponential value of n = 3 for heterogeneous dolostones, and larger values ( n = 6–8) for heterogeneous limestones.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1393290-development-calibration-reactive-transport-model-carbonate-reservoir-porosity-permeability-changes-based-co2-core-flood-experiments','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1393290-development-calibration-reactive-transport-model-carbonate-reservoir-porosity-permeability-changes-based-co2-core-flood-experiments"><span>Development and calibration of a reactive transport model for carbonate reservoir porosity and permeability changes based on CO 2 core-flood experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Smith, Megan M.; Hao, Y.; Carroll, S. A.</p> <p></p> <p>Here, beneficial pore space and permeability enhancements are likely to occur as CO 2-charged fluids partially dissolve carbonate minerals in carbonate reservoir formations used for geologic CO 2 storage. The ability to forecast the extent and impact of changes in porosity and permeability will aid geologic CO 2 storage operations and lower uncertainty in estimates of long-term storage capacity. Our work is directed toward developing calibrated reactive transport models that more accurately capture the chemical impacts of CO 2-fluid-rock interactions and their effects on porosity and permeability by matching pressure, fluid chemistry, and dissolution features that developed as a resultmore » of reaction with CO 2-acidified brines at representative reservoir conditions. We present new results from experiments conducted on seven core samples from the Arbuckle Dolostone (near Wellington, Kansas, USA, recovered as part of the South-Central Kansas CO 2 Demonstration). Cores were obtained from both target reservoir and lower-permeability baffle zones, and together these samples span over 3–4 orders of magnitude of permeability according to downhole measurements. Core samples were nondestructively imaged by X-ray computed tomography and the resulting characterization data were mapped onto a continuum domain to further develop a reactive transport model for a range of mineral and physical heterogeneity. We combine these new results with those from previous experimental studies to more fully constrain the governing equations used in reactive transport models to better estimate the transition of enhanced oil recovery operations to long-term geology CO 2 storage. Calcite and dolomite kinetic rate constants (mol m –2 s –1) derived by fitting the results from core-flood experiments range from k calcite,25C = 10 –6.8 to 10 –4.6, and k dolomite,25C = 10 –7.5 to 10 –5.3. The power law-based porosity-permeability relationship is sensitive to the overall pore space heterogeneity of each core. Stable dissolution fronts observed in the more homogeneous dolostones could be accurately simulated using an exponential value of n = 3. Furthermore, unstable dissolution fronts consisting of preferential flowpaths could be simulated using an exponential value of n = 3 for heterogeneous dolostones, and larger values ( n = 6–8) for heterogeneous limestones.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5992868-hydrocarbon-fluid-ejector-refrigeration-system','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5992868-hydrocarbon-fluid-ejector-refrigeration-system"><span>Hydrocarbon fluid, ejector refrigeration system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kowalski, G.J.; Foster, A.R.</p> <p>1993-08-31</p> <p>A refrigeration system is described comprising: a vapor ejector cycle including a working fluid having a property such that entropy of the working fluid when in a saturated vapor state decreases as pressure decreases, the vapor ejector cycle comprising: a condenser located on a common fluid flow path; a diverter located downstream from the condenser for diverting the working fluid into a primary fluid flow path and a secondary fluid flow path parallel to the primary fluid flow path; an evaporator located on the secondary fluid flow path; an expansion device located on the secondary fluid flow path upstream ofmore » the evaporator; a boiler located on the primary fluid flow path parallel to the evaporator for boiling the working fluid, the boiler comprising an axially extending core region having a substantially constant cross sectional area and a porous capillary region surrounding the core region, the core region extending a length sufficient to produce a near sonic velocity saturated vapor; and an ejector having an outlet in fluid communication with the inlet of the condenser and an inlet in fluid communication with the outlet of the evaporator and the outlet of the boiler and in which the flows of the working fluid from the evaporator and the boiler are mixed and the pressure of the working fluid is increased to at least the pressure of the condenser, the ejector inlet, located downstream from the axially extending core region, including a primary nozzle located sufficiently close to the outlet of the boiler to minimize a pressure drop between the boiler and the primary nozzle, the primary nozzle of the ejector including a converging section having an included angle and length preselected to receive the working fluid from the boiler as a near sonic velocity saturated vapor.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24004491','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24004491"><span>On the genesis of the Earth's magnetism.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roberts, Paul H; King, Eric M</p> <p>2013-09-01</p> <p>Few areas of geophysics are today progressing as rapidly as basic geomagnetism, which seeks to understand the origin of the Earth's magnetism. Data about the present geomagnetic field pours in from orbiting satellites, and supplements the ever growing body of information about the field in the remote past, derived from the magnetism of rocks. The first of the three parts of this review summarizes the available geomagnetic data and makes significant inferences about the large scale structure of the geomagnetic field at the surface of the Earth's electrically conducting fluid core, within which the field originates. In it, we recognize the first major obstacle to progress: because of the Earth's mantle, only the broad, slowly varying features of the magnetic field within the core can be directly observed. The second (and main) part of the review commences with the geodynamo hypothesis: the geomagnetic field is induced by core flow as a self-excited dynamo. Its electrodynamics define 'kinematic dynamo theory'. Key processes involving the motion of magnetic field lines, their diffusion through the conducting fluid, and their reconnection are described in detail. Four kinematic models are presented that are basic to a later section on successful dynamo experiments. The fluid dynamics of the core is considered next, the fluid being driven into motion by buoyancy created by the cooling of the Earth from its primordial state. The resulting flow is strongly affected by the rotation of the Earth and by the Lorentz force, which alters fluid motion by the interaction of the electric current and magnetic field. A section on 'magnetohydrodynamic (MHD) dynamo theory' is devoted to this rotating magnetoconvection. Theoretical treatment of the MHD responsible for geomagnetism culminates with numerical solutions of its governing equations. These simulations help overcome the first major obstacle to progress, but quickly meet the second: the dynamics of Earth's core are too complex, and operate across time and length scales too broad to be captured by any single laboratory experiment, or resolved on present-day computers. The geophysical relevance of the experiments and simulations is therefore called into question. Speculation about what may happen when computational power is eventually able to resolve core dynamics is given considerable attention. The final part of the review is a postscript to the earlier sections. It reflects on the problems that geodynamo theory will have to solve in the future, particularly those that core turbulence presents.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040040130&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dearths%2Bouter%2Bcore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040040130&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dearths%2Bouter%2Bcore"><span>Density Anomalies in the Mantle and the Gravitational Core-Mantle Interaction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuang, Weijia; Liu, Lanbo</p> <p>2003-01-01</p> <p>Seismic studies suggest that the bulk of the mantle is heterogeneous, with density variations in depth as well as in horizontal directions (latitude and longitude). This density variation produces a three- dimensional gravity field throughout the Earth. On the other hand, the core density also varies in both time and space, due to convective core flow. Consequently, the fluid outer core and the solid mantle interact gravitationally due to the mass anomalies in both regions. This gravitational core-mantle interaction could play a significant role in exchange of angular momentum between the core and the mantle, and thus the change in Earth's rotation on time scales of decades and longer. Aiming at estimating the significance of the gravitational core-mantle interaction on Earth's rotation variation, we introduce in our MoSST core dynamics model a heterogeneous mantle, with a density distribution derived from seismic results. In this model, the core convection is driven by the buoyancy forces. And the density variation is determined dynamically with the convection. Numerical simulation is carried out with different parameter values, intending to extrapolate numerical results for geophysical implications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......224A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......224A"><span>Characterization and modeling of the stress and pore-fluid dependent acoustic properties of fractured porous rocks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Almrabat, Abdulhadi M.</p> <p></p> <p>The thesis presents the results of a study of the characterization and modeling of the stress and pore-fluid dependent acoustic properties of fractured porous rocks. A new laboratory High Pressure and High Temperature (HPHT) triaxial testing system was developed to characterize the seismic properties of sandstone under different levels of effective stress confinement and changes in pore-fluid composition. An intact and fractured of Berea sandstones core samples were used in the experimental studies. The laboratory test results were used to develop analytical models for stress-level and pore-fluid dependent seismic velocity of sandstones. Models for stress-dependent P and S-wave seismic velocities of sandstone were then developed based on the assumption that stress-dependencies come from the nonlinear elastic response of micro-fractures contained in the sample under normal and shear loading. The contact shear stiffness was assumed to increase linearly with the normal stress across a micro-fracture, while the contact normal stiffness was assumed to vary as a power law with the micro-fracture normal stress. Both nonlinear fracture normal and shear contact models were validated by experimental data available in the literature. To test the dependency of seismic velocity of sandstone on changes in pore-fluid composition, another series of tests were conducted where P and S-wave velocities were monitored during injection of supercritical CO 2 in samples of Berea sandstone initially saturated with saline water and under constant confining stress. Changes in seismic wave velocity were measured at different levels of supercritical CO2 saturation as the initial saline water as pore-fluid was displaced by supercritical CO 2. It was found that the P- iv wave velocity significantly decreased while the S-wave velocity remained almost constant as the sample supercritical CO2 saturation increased. The dependency of the seismic velocity on changes on pore fluid composition during injection of supercritical CO 2 in Berea sandstone was modeled using a re-derived Biot-Gassmann substitution theory. In using the Biot-Gassmann substitution theory, it was found necessary to account for the changes in the pore-fluid compressibility in terms of the volumetric proportion and distribution of saline water and supercritical CO 2 in the sample pore space. This was done by using the empirical model of Brie et al. to account for the compressibility of mixtures of two-phase immiscible fluids. The combined Biot-Gassman and Brie et al. models were found to represent adequately the changes in P-wave velocity of Berea sandstone during displacement of saline water by supercritical CO2. The third experimental and modeling study addressed shear-wave splitting due to the presence of fractures in a rock mass. Tests were conducted using the high temperature and high pressure (HPHT) triaxial device on samples of Berea sandstone, containing a single induced tensile fracture running along the height of the sample. The fracture was created via a modified Brazilian Split Test loading where the edges of cylindrical samples were loaded on diametrically opposite two points by sharp guillotines. The Joint Roughness Coefficient (JRC) values of the fractured core samples were determined by profilometry and tilt test. The effect of mismatching of the fracture surfaces on shear wave splitting was investigated by applying different amounts of shear displacements to three core samples. The degree of mismatching of the fracture surfaces in the core samples was evaluated using the Joint Matching Coefficient (JMC). Shear-wave splitting, as measured by the difference in magnitudes of shear-wave velocities parallel and perpendicular to the fracture, Vs1 and Vs2 respectively, increases with increasing mismatch of the fracture surfaces and decreases with increasing effective stress, and approaches zero in the effective stress range tested. A model for the stress and JMC dependent shear-wave splitting was developed based on the experimental observations. Finally, the magnitude of shear-wave splitting was correlated with the permeability of the fractured porous sandstone for fluid flow parallel to the induced fracture. (Abstract shortened by UMI.)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhCS1015c2016B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhCS1015c2016B"><span>Digital Core Modelling for Clastic Oil and Gas Reservoir</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belozerov, I.; Berezovsky, V.; Gubaydullin, M.; Yur’ev, A.</p> <p>2018-05-01</p> <p>"Digital core" is a multi-purpose tool for solving a variety of tasks in the field of geological exploration and production of hydrocarbons at various stages, designed to improve the accuracy of geological study of subsurface resources, the efficiency of reproduction and use of mineral resources, as well as applying the results obtained in production practice. The actuality of the development of the "Digital core" software is that even a partial replacement of natural laboratory experiments with mathematical modelling can be used in the operative calculation of reserves in exploratory drilling, as well as in the absence of core material from wells. Or impossibility of its research by existing laboratory methods (weakly cemented, loose, etc. rocks). 3D-reconstruction of the core microstructure can be considered as a cheap and least time-consuming method for obtaining petrophysical information about the main filtration-capacitive properties and fluid motion in reservoir rocks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820052778&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dearths%2Bouter%2Bcore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820052778&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dearths%2Bouter%2Bcore"><span>Effect of the fluid core on changes in the length of day due to long period tides</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wahr, J. M.; Smith, M. L.; Sasao, T.</p> <p>1981-01-01</p> <p>The long period luni-solar tidal potential is known to cause periodic changes in the earth's rotation rate. It is found that the effect of a dissipationless fluid outer core is to reduce the amplitudes of these tidal perturbations by about 11 percent. When the fluid core effect is added to Agnew and Farrell's (1978) estimate of the effect of an equilibrium ocean, the result is in accord with observation. The effects of dissipative processes within the fluid core are also examined. Out-of-phase perturbations are found which could be as large as about 10 ms at 18.6 yr. It is concluded, however, that the poorly understood decade fluctuations in the earth's rotation rate will prohibit observation of this effect.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.G11A0697W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.G11A0697W"><span>The Effects of Core-Mantle Interactions on Earth Rotation, Surface Deformation, and Gravity Changes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watkins, A.; Gross, R. S.; Fu, Y.</p> <p>2017-12-01</p> <p>The length-of-day (LOD) contains a 6-year signal, the cause of which is currently unknown. The signal remains after removing tidal and surface fluid effects, thus the cause is generally believed to be angular momentum exchange between the mantle and core. Previous work has established a theoretical relationship between pressure variations at the core-mantle boundary (CMB) and resulting deformation of the overlying mantle and crust. This study examines globally distributed GPS deformation data in search of this effect, and inverts the discovered global inter-annual component for the CMB pressure variations. The geostrophic assumption is then used to obtain fluid flow solutions at the edge of the core from the CMB pressure variations. Taylor's constraint is applied to obtain the flow deeper within the core, and the equivalent angular momentum and LOD changes are computed and compared to the known 6-year LOD signal. The amplitude of the modeled and measured LOD changes agree, but the degree of period and phase agreement is dependent upon the method of isolating the desired component in the GPS position data. Implications are discussed, and predictions are calculated for surface gravity field changes that would arise from the CMB pressure variations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGP14A..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGP14A..06R"><span>A Paleomagnetic and Diagenetic Study of the Woodford Shale, Oklahoma, U.S.A.: The Timing of Hydrothermal Alteration</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roberts, J.; Elmore, R. D.</p> <p>2017-12-01</p> <p>An oriented Woodford Shale core from the Ardmore Basin near the Ouachita thrust zone (Core B) was sampled to identify diagenetic events and interpret their origin, and to test if a magnetization was present that can be used to date the altering event(s). The shale is extensively altered, exhibiting a complex paragenesis with multiple fractures and brecciated intervals. Multiple hydrothermal minerals, including biotite, magnesite, norsethite, witherite, gorceixite, potassium feldspar, sphalerite, chalcopyrite, and saddle dolomite, are present in and around fractures and in the matrix. Vitrinite and bitumen reflectance measurements indicate VRo values of 1.82% ( 230°C). Two other Woodford Shale cores (A and C) from the Anadarko Basin also contain hydrothermal minerals. Vitrinite and bitumen reflectance data reveal trends between thermal maturity and the level of hydrothermal alteration, with Core A (0.80% VRo ( 125°C) displaying the lowest alteration, and Core C ( 1.5% VRo ( 210°C) displaying intermediate alteration compared to core B. Paleomagnetic analysis of Core B reveals the presence of a characteristic remanent magnetization (ChRM) with south-southeasterly declinations and shallow inclinations that is unblocked by 450°C and is interpreted to reside in magnetite. This ChRM is interpreted to be either a chemical remanent magnetization (CRM) or a thermochemical remanent magnetization (TCRM) acquired during the Late Permian based on the pole position. The presence of specimens with the CRM/TCRM in altered rock and high thermal maturities suggests that this CRM/TCRM originated from alteration by hydrothermal fluids. These results suggest that the Woodford Shale evolved into an open diagenetic system. In addition to causing heightened thermal maturities, these hydrothermal fluids both increased porosity through dissolution and decreased porosity through precipitation of minerals. The Late Permian timing agrees with the dating of hydrothermal alteration found within the Ouachita and Arbuckle Mountains in other studies. The timing for these events is postcollisional, and the most consistent model for the origin of the hydrothermal minerals is fluid flow as a result of faulting that accessed reservoir(s) of warm fluids.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H23G1763H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H23G1763H"><span>Contamination Control of Freeze Shoe Coring System for Collection of Aquifer Sands</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Homola, K.; van Geen, A.; Spivack, A. J.; Grzybowski, B.; Schlottenmier, D.</p> <p>2017-12-01</p> <p>We have developed and tested an original device, the freeze-shoe coring system, designed to recover undisturbed samples of water contained in sand-dominated aquifers. Aquifer sands are notoriously difficult to collect together with porewater from coincident depths, as high hydraulic permeability leads to water drainage and mixing during retrieval. Two existing corer designs were reconfigured to incorporate the freeze-shoe system; a Hydraulic Piston (HPC) and a Rotary (RC) Corer. Once deployed, liquid CO2 contained in an interior tank is channeled to coils at the core head where it changes phase, rapidly cooling the deepest portion of the core. The resulting frozen core material impedes water loss during recovery. We conducted contamination tests to examine the integrity of cores retrieved during a March 2017 yard test deployment. Perfluorocarbon tracer (PFC) was added to the drill fluid and recovered cores were subsampled to capture the distribution of PFC throughout the core length and interior. Samples were collected from two HPC and one RC core and analyzed for PFC concentrations. The lowest porewater contamination, around 0.01% invasive fluid, occurs in the center of both HPC cores. The greatest contamination (up to 10%) occurs at the disturbed edges where core material contacts drill fluid. There was lower contamination in the core interior than top, bottom, and edges, as well as significantly lower contamination in HPC cores that those recovered with the RC. These results confirm that the freeze-shoe system, proposed for field test deployments in West Bengal, India, can successfully collect intact porewater and sediment material with minimal if any contamination from drill fluid.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040062389&hterms=K2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DK2','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040062389&hterms=K2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DK2"><span>Lunar Core and Tides</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.</p> <p>2004-01-01</p> <p>Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pangea.stanford.edu/ERE/db/IGAstandard/search_results.php?showmax=99&CONFERENCE=Stanford%20Geothermal%20Workshop&SortField=Last1&SortOrder=Ascend&Find=Start%20Search&Year=2011','USGSPUBS'); return false;" href="https://pangea.stanford.edu/ERE/db/IGAstandard/search_results.php?showmax=99&CONFERENCE=Stanford%20Geothermal%20Workshop&SortField=Last1&SortOrder=Ascend&Find=Start%20Search&Year=2011"><span>An approach to modeling coupled thermal-hydraulic-chemical processes in geothermal systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Palguta, Jennifer; Williams, Colin F.; Ingebritsen, Steven E.; Hickman, Stephen H.; Sonnenthal, Eric</p> <p>2011-01-01</p> <p>Interactions between hydrothermal fluids and rock alter mineralogy, leading to the formation of secondary minerals and potentially significant physical and chemical property changes. Reactive transport simulations are essential for evaluating the coupled processes controlling the geochemical, thermal and hydrological evolution of geothermal systems. The objective of this preliminary investigation is to successfully replicate observations from a series of hydrothermal laboratory experiments [Morrow et al., 2001] using the code TOUGHREACT. The laboratory experiments carried out by Morrow et al. [2001] measure permeability reduction in fractured and intact Westerly granite due to high-temperature fluid flow through core samples. Initial permeability and temperature values used in our simulations reflect these experimental conditions and range from 6.13 × 10−20 to 1.5 × 10−17 m2 and 150 to 300 °C, respectively. The primary mineralogy of the model rock is plagioclase (40 vol.%), K-feldspar (20 vol.%), quartz (30 vol.%), and biotite (10 vol.%). The simulations are constrained by the requirement that permeability, relative mineral abundances, and fluid chemistry agree with experimental observations. In the models, the granite core samples are represented as one-dimensional reaction domains. We find that the mineral abundances, solute concentrations, and permeability evolutions predicted by the models are consistent with those observed in the experiments carried out by Morrow et al. [2001] only if the mineral reactive surface areas decrease with increasing clay mineral abundance. This modeling approach suggests the importance of explicitly incorporating changing mineral surface areas into reactive transport models.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/4325452','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4325452"><span>COOLED NEUTRONIC REACTOR</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Binner, C.R.; Wilkie, C.B.</p> <p>1958-03-18</p> <p>This patent relates to a design for a reactor of the type in which a fluid coolant is flowed through the active portion of the reactor. This design provides for the cooling of the shielding material as well as the reactor core by the same fluid coolant. The core structure is a solid moderator having coolant channels in which are disposed the fuel elements in rod or slug form. The coolant fluid enters the chamber in the shield, in which the core is located, passes over the inner surface of said chamber, enters the core structure at the center, passes through the coolant channels over the fuel elements and out through exhaust ducts.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750009534','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750009534"><span>Turbulence coefficients and stability studies for the coaxial flow or dissimiliar fluids. [gaseous core nuclear reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weinstein, H.; Lavan, Z.</p> <p>1975-01-01</p> <p>Analytical investigations of fluid dynamics problems of relevance to the gaseous core nuclear reactor program are presented. The vortex type flow which appears in the nuclear light bulb concept is analyzed along with the fluid flow in the fuel inlet region for the coaxial flow gaseous core nuclear reactor concept. The development of numerical methods for the solution of the Navier-Stokes equations for appropriate geometries is extended to the case of rotating flows and almost completes the gas core program requirements in this area. The investigations demonstrate that the conceptual design of the coaxial flow reactor needs further development.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010090463&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dearths%2Bouter%2Bcore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010090463&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dearths%2Bouter%2Bcore"><span>Geodynamo Modeling of Core-Mantle Interactions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuang, Wei-Jia; Chao, Benjamin F.; Smith, David E. (Technical Monitor)</p> <p>2001-01-01</p> <p>Angular momentum exchange between the Earth's mantle and core influences the Earth's rotation on time scales of decades and longer, in particular in the length of day (LOD) which have been measured with progressively increasing accuracy for the last two centuries. There are four possible coupling mechanisms for transferring the axial angular momentum across the core-mantle boundary (CMB): viscous, magnetic, topography, and gravitational torques. Here we use our scalable, modularized, fully dynamic geodynamo model for the core to assess the importance of these torques. This numerical model, as an extension of the Kuang-Bloxham model that has successfully simulated the generation of the Earth's magnetic field, is used to obtain numerical results in various physical conditions in terms of specific parameterization consistent with the dynamical processes in the fluid outer core. The results show that depending on the electrical conductivity of the lower mantle and the amplitude of the boundary topography at CMB, both magnetic and topographic couplings can contribute significantly to the angular momentum exchange. This implies that the core-mantle interactions are far more complex than has been assumed and that there is unlikely a single dominant coupling mechanism for the observed decadal LOD variation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780025438','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780025438"><span>A mean spherical model for soft potentials: The hard core revealed as a perturbation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rosenfeld, Y.; Ashcroft, N. W.</p> <p>1978-01-01</p> <p>The mean spherical approximation for fluids is extended to treat the case of dense systems interacting via soft-potentials. The extension takes the form of a generalized statement concerning the behavior of the direct correlation function c(r) and radial distribution g(r). From a detailed analysis that views the hard core portion of a potential as a perturbation on the whole, a specific model is proposed which possesses analytic solutions for both Coulomb and Yukawa potentials, in addition to certain other remarkable properties. A variational principle for the model leads to a relatively simple method for obtaining numerical solutions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11415112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11415112"><span>Low-temperature behavior of core-softened models: water and silica behavior.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jagla, E A</p> <p>2001-06-01</p> <p>A core-softened model of a glass forming fluid is numerically studied in the limit of very low temperatures. The model shows two qualitatively different behaviors depending on the strength of the attraction between particles. For no or low attraction, the changes of density as a function of pressure are smooth, although hysteretic due to mechanical metastabilities. For larger attraction, sudden changes of density upon compressing and decompressing occur. This global mechanical instability is correlated to the existence of a thermodynamic first-order amorphous-amorphous transition. The two different behaviors obtained correspond qualitatively to the different phenomenology observed in silica and water.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23839922','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23839922"><span>Study of low speed flow cytometry for diffraction imaging with different chamber and nozzle designs.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sa, Yu; Feng, Yuanming; Jacobs, Kenneth M; Yang, Jun; Pan, Ran; Gkigkitzis, Ioannis; Lu, Jun Q; Hu, Xin-Hua</p> <p>2013-11-01</p> <p>Achieving effective hydrodynamic focusing and flow stability at low speed presents a challenging design task in flow cytometry for studying phenomena such as cell adhesion and diffraction imaging of cells with low-cost cameras. We have developed different designs of flow chamber and sheath nozzle to accomplish the above goal. A 3D computational model of the chambers has been established to simulate the fluid dynamics in different chamber designs and measurements have been performed to determine the velocity and size distributions of the core fluid from the nozzle. Comparison of the simulation data with experimental results shows good agreement. With the computational model significant insights were gained for optimization of the chamber design and improvement of the cell positioning accuracy for study of slow moving cells. The benefit of low flow speed has been demonstrated also by reduced blurring in the diffraction images of single cells. Based on these results, we concluded that the new designs of chamber and sheath nozzle produce stable hydrodynamic focusing of the core fluid at low speed and allow detailed study of cellular morphology under various rheological conditions using the diffraction imaging method. © 2013 International Society for Advancement of Cytometry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27592513','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27592513"><span>Semipermeable Elastic Microcapsules for Gas Capture and Sensing.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nabavi, Seyed Ali; Vladisavljević, Goran T; Gu, Sai; Manović, Vasilije</p> <p>2016-09-27</p> <p>Monodispersed microcapsules for gas capture and sensing were developed consisting of elastic semipermeable polymer shells of tunable size and thickness and pH-sensitive, gas selective liquid cores. The microcapsules were produced using glass capillary microfluidics and continuous on-the-fly photopolymerization. The inner fluid was 5-30 wt % K2CO3 solution with m-cresol purple, the middle fluid was a UV-curable liquid silicon rubber containing 0-2 wt % Dow Corning 749 fluid, and the outer fluid was aqueous solution containing 60-70 wt % glycerol and 0.5-2 wt % stabilizer (poly(vinyl alcohol), Tween 20, or Pluronic F-127). An analytical model was developed and validated for prediction of the morphology of the capsules under osmotic stress based on the shell properties and the osmolarity of the storage and core solutions. The minimum energy density and UV light irradiance needed to achieve complete shell polymerization were 2 J·cm(-2) and 13.8 mW·cm(-2), respectively. After UV exposure, the curing time for capsules containing 0.5 wt % Dow Corning 749 fluid in the middle phase was 30-40 min. The CO2 capture capacity of 30 wt % K2CO3 capsules was 1.6-2 mmol/g depending on the capsule size and shell thickness. A cavitation bubble was observed in the core when the internal water was abruptly removed by capillary suction, whereas a gradual evaporation of internal water led to buckling of the shell. The shell was characterized using TGA, DSC, and FTIR. The shell degradation temperature was 450-460 °C.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24320299','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24320299"><span>Phase behavior of the modified-Yukawa fluid and its sticky limit.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schöll-Paschinger, Elisabeth; Valadez-Pérez, Néstor E; Benavides, Ana L; Castañeda-Priego, Ramón</p> <p>2013-11-14</p> <p>Simple model systems with short-range attractive potentials have turned out to play a crucial role in determining theoretically the phase behavior of proteins or colloids. However, as pointed out by D. Gazzillo [J. Chem. Phys. 134, 124504 (2011)], one of these widely used model potentials, namely, the attractive hard-core Yukawa potential, shows an unphysical behavior when one approaches its sticky limit, since the second virial coefficient is diverging. However, it is exactly this second virial coefficient that is typically used to depict the experimental phase diagram for a large variety of complex fluids and that, in addition, plays an important role in the Noro-Frenkel scaling law [J. Chem. Phys. 113, 2941 (2000)], which is thus not applicable to the Yukawa fluid. To overcome this deficiency of the attractive Yukawa potential, D. Gazzillo has proposed the so-called modified hard-core attractive Yukawa fluid, which allows one to correctly obtain the second and third virial coefficients of adhesive hard-spheres starting from a system with an attractive logarithmic Yukawa-like interaction. In this work we present liquid-vapor coexistence curves for this system and investigate its behavior close to the sticky limit. Results have been obtained with the self-consistent Ornstein-Zernike approximation (SCOZA) for values of the reduced inverse screening length parameter up to 18. The accuracy of SCOZA has been assessed by comparison with Monte Carlo simulations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15965599','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15965599"><span>An experimental and finite element poroelastic creep response analysis of an intervertebral hydrogel disc model in axial compression.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Silva, P; Crozier, S; Veidt, M; Pearcy, M J</p> <p>2005-07-01</p> <p>A hydrogel intervertebral disc (IVD) model consisting of an inner nucleus core and an outer anulus ring was manufactured from 30 and 35% by weight Poly(vinyl alcohol) hydrogel (PVA-H) concentrations and subjected to axial compression in between saturated porous endplates at 200 N for 11 h, 30 min. Repeat experiments (n=4) on different samples (N=2) show good reproducibility of fluid loss and axial deformation. An axisymmetric nonlinear poroelastic finite element model with variable permeability was developed using commercial finite element software to compare axial deformation and predicted fluid loss with experimental data. The FE predictions indicate differential fluid loss similar to that of biological IVDs, with the nucleus losing more water than the anulus, and there is overall good agreement between experimental and finite element predicted fluid loss. The stress distribution pattern indicates important similarities with the biological IVD that includes stress transference from the nucleus to the anulus upon sustained loading and renders it suitable as a model that can be used in future studies to better understand the role of fluid and stress in biological IVDs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=S89-44035&hterms=drawing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddrawing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=S89-44035&hterms=drawing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddrawing"><span>Labeled drawing of Jupiter showing its core and composition</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1989-01-01</p> <p>Labeled drawing of Jupiter identifies fluid molecular hydrogen, transition zone, fluid metallic hydrogen, and possible core and the composition of its atmosphere - cloud tops - aerosols, ammonia crystals, ammonium hydrosulfide clouds, ice crystal clouds, and water droplets.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1339576-computationally-efficient-method-full-core-conjugate-heat-transfer-modeling-sodium-fast-reactors','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1339576-computationally-efficient-method-full-core-conjugate-heat-transfer-modeling-sodium-fast-reactors"><span>A computationally efficient method for full-core conjugate heat transfer modeling of sodium fast reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Hu, Rui; Yu, Yiqi</p> <p>2016-09-08</p> <p>For efficient and accurate temperature predictions of sodium fast reactor structures, a 3-D full-core conjugate heat transfer modeling capability is developed for an advanced system analysis tool, SAM. The hexagon lattice core is modeled with 1-D parallel channels representing the subassembly flow, and 2-D duct walls and inter-assembly gaps. The six sides of the hexagon duct wall and near-wall coolant region are modeled separately to account for different temperatures and heat transfer between coolant flow and each side of the duct wall. The Jacobian Free Newton Krylov (JFNK) solution method is applied to solve the fluid and solid field simultaneouslymore » in a fully coupled fashion. The 3-D full-core conjugate heat transfer modeling capability in SAM has been demonstrated by a verification test problem with 7 fuel assemblies in a hexagon lattice layout. In addition, the SAM simulation results are compared with RANS-based CFD simulations. Very good agreements have been achieved between the results of the two approaches.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030111565&hterms=K2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DK2','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030111565&hterms=K2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DK2"><span>Lunar Rotation and the Lunar Interior</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.; Dickey, J. O.</p> <p>2003-01-01</p> <p>Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/ solid-mantle boundary, and tidal Love number k2. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) and fluid core moment of inertia. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core plus Love number. Past detection of CMB flattening has been marginal but is improving, while direct detection of the core moment has not yet been achieved. Three decades of Lunar Laser Ranging (LLR) data are analyzed using a weighted least-squares approach. The lunar solution parameters include dissipation at the fluid-core/solid-mantle boundary, tidal dissipation, dissipation-related coefficients for rotation and orientation terms, potential Love number k2, a correction to the constant term in the tilt of the equator to the ecliptic which is meant to approximate the influence of core-mantle boundary flattening, and displacement Love numbers h2 and l2. Several solutions, with different combinations of solution parameters and constraints, are considered.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSM.P23A..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSM.P23A..01S"><span>Core Composition and the Magnetic Field of Mercury</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spohn, T.; Breuer, D.</p> <p>2005-05-01</p> <p>The density of Mercury suggests a core of approximately 1800 km radius and a mantle of approximately 600 km thickness. Convection in the mantle is often claimed to be capable of freezing the core over the lifetime of the solar system if the core is nearly pure iron. The thermal history calculations of Stevenson et al. (1983) and Schubert et al. (1988) suggest that about 5 weight-% sulphur are required to lower the core liquidus sufficiently to prevent complete freezing of the core and maintain a significant fluid outer core shell. Other candidates for a light alloying element require similarly large concentrations. The requirement of a significant concentration of volatile elements in the core is likely to be at variance with cosmochemical arguments for a mostly refractory, volatile poor composition of the planet. We have re-addressed the question of the freezing of Mercury's core using parameterized convection models based on the stagnant lid theory of planetary mantle convection. We have compared these results to earlier calculations (Conzelmann and Spohn, 1999) of Hermian mantle convection using a finite-amplitude convection code. We find consistently that the stagnant lid tends to thermally insulate the deep interior and we find mantle and core temperatures significantly larger than those calculated by Stevenson et al. (1983) and Schubert et al. (1988). As a consequence we find fluid outer core shells for reasonable mantle rheology parameters even for compositions with as little as 0.1 weight-% sulphur. Stevenson, D.J., T. Spohn, and G. Schubert. Icarus, 54, 466, 1983. Schubert, G. M.N. Ross, D.J. Stevenson, and T. Spohn, in Mercury, F. Vilas, C.R. Chapman and M.S. Matthews, eds., p.429, 1988. Conzelmann, V. and T. Spohn, Bull. Am. Astr. Soc., 31, 1102, 1999.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22518733-stochasticity-efficiency-simplified-models-core-collapse-supernova-explosions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22518733-stochasticity-efficiency-simplified-models-core-collapse-supernova-explosions"><span>STOCHASTICITY AND EFFICIENCY IN SIMPLIFIED MODELS OF CORE-COLLAPSE SUPERNOVA EXPLOSIONS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cardall, Christian Y.; Budiardja, Reuben D., E-mail: cardallcy@ornl.gov, E-mail: reubendb@utk.edu</p> <p>2015-11-01</p> <p>We present an initial report on 160 simulations of a highly simplified model of the post-bounce core-collapse supernova environment in three spatial dimensions (3D). We set different values of a parameter characterizing the impact of nuclear dissociation at the stalled shock in order to regulate the post-shock fluid velocity, thereby determining the relative importance of convection and the stationary accretion shock instability (SASI). While our convection-dominated runs comport with the paradigmatic notion of a “critical neutrino luminosity” for explosion at a given mass accretion rate (albeit with a nontrivial spread in explosion times just above threshold), the outcomes of ourmore » SASI-dominated runs are much more stochastic: a sharp threshold critical luminosity is “smeared out” into a rising probability of explosion over a ∼20% range of luminosity. We also find that the SASI-dominated models are able to explode with 3–4 times less efficient neutrino heating, indicating that progenitor properties, and fluid and neutrino microphysics, conducive to the SASI would make the neutrino-driven explosion mechanism more robust.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930013622','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930013622"><span>On the nonlinear interfacial instability of rotating core-annular flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coward, Aidrian V.; Hall, Philip</p> <p>1993-01-01</p> <p>The interfacial stability of rotating core-annular flows is investigated. The linear and nonlinear effects are considered for the case when the annular region is very thin. Both asymptotic and numerical methods are used to solve the flow in the core and film regions which are coupled by a difference in viscosity and density. The long-term behavior of the fluid-fluid interface is determined by deriving its nonlinear evolution in the form of a modified Kuramoto-Sivashinsky equation. We obtain a generalization of this equation to three dimensions. The flows considered are applicable to a wide array of physical problems where liquid films are used to lubricate higher or lower viscosity core fluids, for which a concentric arrangement is desired. Linearized solutions show that the effects of density and viscosity stratification are crucial to the stability of the interface. Rotation generally destabilizes non-axisymmetric disturbances to the interface, whereas the centripetal forces tend to stabilize flows in which the film contains the heavier fluid. Nonlinear affects allow finite amplitude helically travelling waves to exist when the fluids have different viscosities.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1336451-cfd-analysis-upper-plenum-flow-sodium-cooled-small-modular-reactor','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1336451-cfd-analysis-upper-plenum-flow-sodium-cooled-small-modular-reactor"><span>CFD Analysis of Upper Plenum Flow for a Sodium-Cooled Small Modular Reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kraus, A.; Hu, R.</p> <p>2015-01-01</p> <p>Upper plenum flow behavior is important for many operational and safety issues in sodium fast reactors. The Prototype Gen-IV Sodium Fast Reactor (PGSFR), a pool-type, 150 MWe output power design, was used as a reference case for a detailed characterization of upper plenum flow for normal operating conditions. Computational Fluid Dynamics (CFD) simulation was utilized with detailed geometric modeling of major structures. Core outlet conditions based on prior system-level calculations were mapped to approximate the outlet temperatures and flow rates for each core assembly. Core outlet flow was found to largely bypass the Upper Internal Structures (UIS). Flow curves overmore » the shield and circulates within the pool before exiting the plenum. Cross-flows and temperatures were evaluated near the core outlet, leading to a proposed height for the core outlet thermocouples to ensure accurate assembly-specific temperature readings. A passive scalar was used to evaluate fluid residence time from core outlet to IHX inlet, which can be used to assess the applicability of various methods for monitoring fuel failure. Additionally, the gas entrainment likelihood was assessed based on the CFD simulation results. Based on the evaluation of velocity gradients and turbulent kinetic energies and the available gas entrainment criteria in the literature, it was concluded that significant gas entrainment is unlikely for the current PGSFR design.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.G41C0370D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.G41C0370D"><span>Historical Variations in Inner Core Rotation and Polar Motion at Decade Timescales</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dumberry, M.</p> <p>2005-12-01</p> <p>Exchanges of angular momentum between the mantle, the fluid core and the solid inner core result in changes in the Earth's rotation. Torques in the axial direction produce changes in amplitude, or changes in length of day, while torques in the equatorial direction lead to changes in orientation of the rotation vector with respect to the mantle, or polar motion. In this work, we explore the possibility that a combination of electromagnetic and gravitational torques on the inner core can reproduce the observed decadal variations in polar motion known as the Markowitz wobble. Torsional oscillations, which involve azimuthal motions in the fluid core with typical periods of decades, entrain the inner core by electromagnetic traction. When the inner core is axially rotated, its surfaces of constant density are no longer aligned with the gravitational potential from mantle density heterogeneities, and this results in a gravitational torque between the two. The axial component of this torque has been previously described and is believed to be partly responsible for decadal changes in length of day. In this work, we show that it has also an equatorial component, which produces a tilt of the inner core and results in polar motion. The polar motion produced by this mechanism depends on the density structure in the mantle, the rheology of the inner core, and the time-history of the angle of axial misalignment between the inner core and the mantle. We reconstruct the latter using a model of torsional oscillations derived from geomagnetic secular variation. From this time-history, and by using published models of mantle density structure, we show that we can reproduce the salient characteristics of the Markowitz wobble: an eccentric decadal polar motion of 30-50 milliarcsecs oriented along a specific longitude. We discuss the implications of this result, noting that a match in both amplitude and phase of the observed Markowitz wobble allows the recovery of the historical rotational variations of the inner core, and also provides constraints on structure, rheology and dynamics of the Earth's deep interior that cannot be observed directly.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6039852-fluid-mechanic-based-model-sedimentation-flocculated-suspensions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6039852-fluid-mechanic-based-model-sedimentation-flocculated-suspensions"><span>A fluid-mechanic-based model for the sedimentation of flocculated suspensions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chhabra, R.P.; Prasad, D.</p> <p>1991-02-01</p> <p>Due to the wide occurrence of the suspensions of fine particles in mineral and chemical processing industries, considerable interest has been shown in modeling the hydrodynamic behavior of such systems. A fluid-mechanic-based analysis is presented for the settling behavior of flocculated4d suspensions. Flocs have been modeled as composite spheres consisting of a solid core embedded in a shell of homogeneous and isotropic porous medium. Theoretical estimates of the rates of sedimentation for flocculated suspensions are obtained by solving the equations of continuity and of motion. The interparticle interactions are incorporated into the analysis by employing the Happel free surface cellmore » model. The results reported embrace wide ranges of conditions of floc size and concentration.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19..399T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19..399T"><span>Head-on collision of the second mode internal solitary waves</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Terletska, Kateryna; Maderich, Vladimir; Jung, Kyung Tae</p> <p>2017-04-01</p> <p>Second mode internal waves are widespread in offshore areas, and they frequently follow the first mode internal waves on the oceanic shelf. Large amplitude internal solitary waves (ISW) of second mode containing trapped cores associated with closed streamlines can also transport plankton and nutrients. An interaction of ISWs with trapped cores takes place in a specific manner. It motivated us to carry out a computational study of head-on collision of ISWs of second mode propagating in a laboratory-scale numerical tank using the nonhydrostatic 3D numerical model based on the Navier-Stokes equations for a continuously stratified fluid. Three main classes of ISW of second mode propagating in the pycnocline layer of thickness h between homogeneous deep layers can be identified: (i) the weakly nonlinear waves; (ii) the stable strongly nonlinear waves with trapped cores; and (iii) the shear unstable strongly nonlinear waves (Maderich et al., 2015). Four interaction regimes for symmetric collision were separated from simulation results using this classification: (A) an almost elastic interaction of the weakly nonlinear waves; (B) a non-elastic interaction of waves with trapped cores when ISW amplitudes were close to critical non-dimensional amplitude a/h; (C) an almost elastic interaction of stable strongly nonlinear waves with trapped cores; (D) non-elastic interaction of the unstable strongly nonlinear waves. The unexpected result of simulation was that relative loss of energy due to the collision was maximal for regime B. New regime appeared when ISW of different amplitudes belonged to class (ii) collide. In result of interaction the exchange of mass between ISW occurred: the trapped core of smaller wave was entrained by core of larger ISW without mixing forming a new ISW of larger amplitude whereas in smaller ISW core of smaller wave totally substituted by fluid from larger wave. Overall, the wave characteristics induced by head-on collision agree well with the results of several available laboratory experiments. References [1] V. Maderich, K. T. Jung, K. Terletska, I. Brovchenko, T. Talipova, "Incomplete similarity of internal solitary waves with trapped core," Fluid Dynamics Research 47, 035511 (2015).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016QSRv..135..154W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016QSRv..135..154W"><span>Pore fluids and the LGM ocean salinity-Reconsidered</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wunsch, Carl</p> <p>2016-03-01</p> <p>Pore fluid chlorinity/salinity data from deep-sea cores related to the salinity maximum of the last glacial maximum (LGM) are analyzed using estimation methods deriving from linear control theory. With conventional diffusion coefficient values and no vertical advection, results show a very strong dependence upon initial conditions at -100 ky. Earlier inferences that the abyssal Southern Ocean was strongly salt-stratified in the LGM with a relatively fresh North Atlantic Ocean are found to be consistent within uncertainties of the salinity determination, which remain of order ±1 g/kg. However, an LGM Southern Ocean abyss with an important relative excess of salt is an assumption, one not required by existing core data. None of the present results show statistically significant abyssal salinity values above the global average, and results remain consistent, apart from a general increase owing to diminished sea level, with a more conventional salinity distribution having deep values lower than the global mean. The Southern Ocean core does show a higher salinity than the North Atlantic one on the Bermuda Rise at different water depths. Although much more sophisticated models of the pore-fluid salinity can be used, they will only increase the resulting uncertainties, unless considerably more data can be obtained. Results are consistent with complex regional variations in abyssal salinity during deglaciation, but none are statistically significant.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAMTP..59...22K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAMTP..59...22K"><span>Steady Flow Generated by a Core Oscillating in a Rotating Spherical Cavity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozlov, V. G.; Subbotin, S. V.</p> <p>2018-01-01</p> <p>Steady flow generated by oscillations of an inner solid core in a fluid-filled rotating spherical cavity is experimentally studied. The core with density less than the fluid density is located near the center of the cavity and is acted upon by a centrifugal force. The gravity field directed perpendicular to the rotation axis leads to a stationary displacement of the core from the rotation axis. As a result, in the frame of reference attached to the cavity, the core performs circular oscillation with frequency equal to the rotation frequency, and its center moves along a circular trajectory in the equatorial plane around the center of the cavity. For the differential rotation of the core to be absent, one of the poles of the core is connected to the nearest pole of the cavity with a torsionally elastic, flexible fishing line. It is found that the oscillation of the core generates axisymmetric azimuthal fluid flow in the cavity which has the form of nested liquid columns rotating with different angular velocities. Comparison with the case of a free oscillating core which performs mean differential rotation suggests the existence of two mechanisms of flow generation (due to the differential rotation of the core in the Ekman layer and due to the oscillation of the core in the oscillating boundary layers).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150008968','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150008968"><span>Dynamic Responses of the Earth's Outer Core to Assimilation of Observed Geomagnetic Secular Variation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuang, Weijia; Tangborn, Andrew</p> <p>2014-01-01</p> <p>Assimilation of surface geomagnetic observations and geodynamo models has advanced very quickly in recent years. However, compared to advanced data assimilation systems in meteorology, geomagnetic data assimilation (GDAS) is still in an early stage. Among many challenges ranging from data to models is the disparity between the short observation records and the long time scales of the core dynamics. To better utilize available observational information, we have made an effort in this study to directly assimilate the Gauss coefficients of both the core field and its secular variation (SV) obtained via global geomagnetic field modeling, aiming at understanding the dynamical responses of the core fluid to these additional observational constraints. Our studies show that the SV assimilation helps significantly to shorten the dynamo model spin-up process. The flow beneath the core-mantle boundary (CMB) responds significantly to the observed field and its SV. The strongest responses occur in the relatively small scale flow (of the degrees L is approx. 30 in spherical harmonic expansions). This part of the flow includes the axisymmetric toroidal flow (of order m = 0) and non-axisymmetric poloidal flow with m (is) greater than 5. These responses can be used to better understand the core flow and, in particular, to improve accuracies of predicting geomagnetic variability in future.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730044612&hterms=internal+factors+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dinternal%2Bfactors%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730044612&hterms=internal+factors+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dinternal%2Bfactors%2Btheory"><span>On the physical basis of a theory of human thermoregulation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Iberall, A. S.; Schindler, A. M.</p> <p>1973-01-01</p> <p>Theoretical study of the physical factors which are responsible for thermoregulation in nude resting humans in a physical steady state. The behavior of oxidative metabolism, evaporative and convective thermal fluxes, fluid heat transfer, internal and surface temperatures, and evaporative phase transitions is studied by physiological/physical modeling techniques. The modeling is based on the theories that the body has a vital core with autothermoregulation, that the vital core contracts longitudinally, that the temperature of peripheral regions and extremities decreases towards the ambient, and that a significant portion of the evaporative heat may be lost underneath the skin. A theoretical basis is derived for a consistent modeling of steady-state thermoregulation on the basis of these theories.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612078T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612078T"><span>Low grade metamorphism fluid circulation in a sedimentary environment thrust fault zone: properties and modeling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trincal, Vincent; Lacroix, Brice; Buatier, Martine D.; Charpentier, Delphine; Labaume, Pierre; Lahfid, Abdeltif</p> <p>2014-05-01</p> <p>In fold-and-thrust belts, shortening is mainly accommodated by thrust faults that can constitute preferential pathways for fluid circulation. The present study focuses on the Pic de Port Vieux thrust, a second-order thrust related to major Gavarnie thrust in the Axial Zone of the Pyrenees. The fault juxtaposes lower Triassic red siltstones and sandstones in the hanging-wall and Upper Cretaceous limestone in the footwall. A dense network of synkinematic quartz-chlorite veins is present in outcrop and allows to unravel the nature of the fluid that circulated in the fault zone. The hanging wall part of fault zone comprises a core which consists of intensely foliated phyllonite; the green color of this shear zone is related to the presence of abundant newly-formed chlorite. Above, the damage zone consists of red pelites and sandstones. Both domains feature kinematic markers like S-C type shear structures associated with shear and extension quartz-chlorite veins and indicate a top to the south displacement. In the footwall, the limestone display increasing mylonitization and marmorization when getting close to the contact. In order to investigate the mineralogical and geochemical changes induced by deformation and subsequent fluid flow, sampling was conducted along a complete transect of the fault zone, from the footwall limestone to the red pelites of the hanging wall. In the footwall limestone, stable isotope and Raman spectroscopy analyzes were performed. The strain gradient is strongly correlated with a high decrease in δ18OV PDB values (from -5.5 to -14) when approaching the thrust (i.e. passing from limestone to marble) while the deformation temperatures estimated with Raman spectroscopy on carbon remain constant around 300° C. These results suggest that deformation is associated to a dynamic calcite recrystallization of carbonate in a fluid-open system. In the hanging wall, SEM observations, bulk chemical XRF analyses and mineral quantification from XRD analyses were conducted in order to compare the green phyllonites from the fault core zone with the red pelites from the damage zone. Quartz, muscovite 2M1, chlorite (clinochlore), calcite and rutile are present in all samples. Hematite occurs in the damage zone but is absent in the core zone. Synkinematic chlorites are abundant in the core and damage zones and are mainly located in veins, sometimes in association with quartz. The temperature of formation of these newly-formed chlorites is 300-350° C according to Inoue (2009) geothermometer. Mössbauer spectroscopic analyses were performed on bulk rock samples. In the damage zone, Fe3+/Fetotal vary between 0.7 and 0.8, whereas in the core zone Fe3+/Fetotal is about 0.35. This decrease in Fe3+ from the damage zone to the core zone can be related to the dissolution of hematite. In contrast, Fe3+/Fetotal in phyllosilicates is clearly related to the chlorite content relative to mica, as Fe2+ increases with chlorite content. All these data allow us to propose a model of fluid circulation in relation with the Pic de Port Vieux thrust activity. The origin of the fluid, its interactions with host-rock and the consequences on fault zone mineralizations will be discussed. Inoue, A., Meunier, A., Patrier-Mas, P., Rigault, C., Beaufort, D., Vieillard, P., 2009. Application of chemical geothermometry to low-temperature trioctahedral chlorites. Clay Clay Min. 57, 371-382.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15776816','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15776816"><span>The effects of substrate size, surface area, and density on coat thickness of multi-particulate dosage forms.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Heinicke, Grant; Matthews, Frank; Schwartz, Joseph B</p> <p>2005-01-01</p> <p>Drugs layering experiments were performed in a fluid bed fitted with a rotor granulator insert using diltiazem as a model drug. The drug was applied in various quantities to sugar spheres of different mesh sizes to give a series of drug-layered sugar spheres (cores) of different potency, size, and weight per particle. The drug presence lowered the bulk density of the cores in proportion to the quantity of added drug. Polymer coating of each core lot was performed in a fluid bed fitted with a Wurster insert. A series of polymer-coated cores (pellets) was removed from each coating experiment. The mean diameter of each core and each pellet sample was determined by image analysis. The rate of change of diameter on polymer addition was determined for each starting size of core and compared to calculated values. The core diameter was displaced from the line of best fit through the pellet diameter data. Cores of different potency with the same size distribution were made by layering increasing quantities of drug onto sugar spheres of decreasing mesh size. Equal quantities of polymer were applied to the same-sized core lots and coat thickness was measured. Weight/weight calculations predict equal coat thickness under these conditions, but measurable differences were found. Simple corrections to core charge weight in the Wurster insert were successfully used to manufacture pellets having the same coat thickness. The sensitivity of the image analysis technique in measuring particle size distributions (PSDs) was demonstrated by measuring a displacement in PSD after addition of 0.5% w/w talc to a pellet sample.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JChPh.120.4844B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JChPh.120.4844B"><span>Hard sphere perturbation theory for fluids with soft-repulsive-core potentials</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ben-Amotz, Dor; Stell, George</p> <p>2004-03-01</p> <p>The thermodynamic properties of fluids with very soft repulsive-core potentials, resembling those of some liquid metals, are predicted with unprecedented accuracy using a new first-order thermodynamic perturbation theory. This theory is an extension of Mansoori-Canfield/Rasaiah-Stell (MCRS) perturbation theory, obtained by including a configuration integral correction recently identified by Mon, who evaluated it by computer simulation. In this work we derive an analytic expression for Mon's correction in terms of the radial distribution function of the soft-core fluid, g0(r), approximated using Lado's self-consistent extension of Weeks-Chandler-Andersen (WCA) theory. Comparisons with WCA and MCRS predictions show that our new extended-MCRS theory outperforms other first-order theories when applied to fluids with very soft inverse-power potentials (n⩽6), and predicts free energies that are within 0.3kT of simulation results up to the fluid freezing point.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.2870F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.2870F"><span>A simple and inexpensive technique for assessing microbial contamination during drilling operations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Friese, André; Vuillemin, Aurèle; Kallmeyer, Jens; Wagner, Dirk</p> <p>2016-04-01</p> <p>Exploration of the Deep Biosphere relies on drilling, which inevitably causes infiltration of drilling fluids, containing allochthonous microbes from the surface, into the core. Therefore it is absolutely necessary to trace contamination of the sediment core in order to identify uncontaminated samples for microbiological investigations. Several techniques have been used in the past, including fluorescent dyes, perfluorocarbon tracers and fluorescent microspheres. Fluorescent dyes are inexpensive and easy to analyze on-site but are sensitive to light, pH and water chemistry. Furthermore, significant sorption to clays can decrease the fluorescence signal. Perfluorocarbon tracers are chemically inert hydrophobic compounds that can be detected with high sensitivity via gas chromatography, which might be a problem for on-site analysis. Samples have to be taken immediately after core retrieval as otherwise the volatile tracer will have diffused out of the core. Microsphere tracers are small (0.2 - 0.5 μm diameter) fluorescent plastic particles that are mixed into the drilling fluid. For analysis, these particles can be extracted from the sediment sample, transferred onto a filter and quantified via fluorescence microscopy. However, they are very expensive and therefore unsuitable for deep drilling operations that need large amounts of drilling fluids. Here, we present an inexpensive contamination control approach using fluorescent pigments initially used for coloring plastics. The price of this tracer is nearly three orders of magnitude lower than conventional microsphere tracers. Its suitability for large drilling campaigns was tested at the ICDP Deep Drilling at Lake Towuti, Sulawesi, Indonesia. The tracer was diluted 1:1000 in lake water, which was used as the drilling fluid. Additionally, a plastic bag filled with 20 mL of undiluted tracer was attached to the core catcher to increase the amount of particles in the liner fluid right at the core. After core retrieval, the core was cut and the liner fluid collected. From each whole round core (WRC) that was taken for microbiological and biogeochemical analyses, small samples of 1 cc were retrieved with sterile cutoff syringes from the rim, the center and an intermediate position. After dilution and homogenization in 9 mL MilliQ water, 10 μL of the sediment slurry was transferred onto a filter membrane and particles counted via fluorescence microscopy. Additionally, particles in the liner fluid were also quantified. This allows the quantification of the amount of drilling fluid that has entered the sediment sample during drilling. The minimum detectable volume of drilling fluid was in the order of single nanoliters per cc of sediment, which is in the range of established techniques. The presented method requires only a minimum of equipment and allows rapid determination of contamination in the sediment core and an easy to handle on-site analysis at low costs. The sensitivity is in the same range as perfluorocarbon and microsphere tracer applications. Thus, it offers an inexpensive but powerful technique for contamination assessment for future drilling campaigns.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036580','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036580"><span>Pore fluid geochemistry from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Torres, M.E.; Collett, T.S.; Rose, K.K.; Sample, J.C.; Agena, W.F.; Rosenbaum, E.J.</p> <p>2011-01-01</p> <p>The BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled and cored from 606.5 to 760.1. m on the North Slope of Alaska, to evaluate the occurrence, distribution and formation of gas hydrate in sediments below the base of the ice-bearing permafrost. Both the dissolved chloride and the isotopic composition of the water co-vary in the gas hydrate-bearing zones, consistent with gas hydrate dissociation during core recovery, and they provide independent indicators to constrain the zone of gas hydrate occurrence. Analyses of chloride and water isotope data indicate that an observed increase in salinity towards the top of the cored section reflects the presence of residual fluids from ion exclusion during ice formation at the base of the permafrost layer. These salinity changes are the main factor controlling major and minor ion distributions in the Mount Elbert Well. The resulting background chloride can be simulated with a one-dimensional diffusion model, and the results suggest that the ion exclusion at the top of the cored section reflects deepening of the permafrost layer following the last glaciation (???100 kyr), consistent with published thermal models. Gas hydrate saturation values estimated from dissolved chloride agree with estimates based on logging data when the gas hydrate occupies more than 20% of the pore space; the correlation is less robust at lower saturation values. The highest gas hydrate concentrations at the Mount Elbert Well are clearly associated with coarse-grained sedimentary sections, as expected from theoretical calculations and field observations in marine and other arctic sediment cores. ?? 2009 Elsevier Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMDI43A1769A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMDI43A1769A"><span>Seismic Wave Velocity in Earth's Shallow Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alexandrakis, C.; Eaton, D. W.</p> <p>2008-12-01</p> <p>Studies of the outer core indicate that it is composed of liquid Fe and Ni alloyed with a ~10% fraction of light elements such as O, S or Si. Recently, unusual features, such as sediment accumulation, immiscible fluid layers or stagnant convection, have been predicted in the shallow core region. Secular cooling and compositional buoyancy drive vigorous convection that sustains the geodynamo, although critical details of light-element composition and thermal regime remain uncertain. Seismic velocity models can provide important constraints on the light element composition, however global reference models, such as Preliminary Reference Earth Model (PREM), IASP91 and AK135 vary significantly in the 200 km below the core-mantle boundary. Past studies of the outermost core velocity structure have been hampered by traveltime uncertainties due to lowermost mantle heterogeneities. The recently published Empirical Transfer Function (ETF) method has been shown to reduce the uncertainty using a waveform stacking approach to improve global observations of SmKS teleseismic waves. Here, we apply the ETF method to achieve a precise top-of-core velocity measurement of 8.05 ± 0.03 km/s. This new model accords well with PREM. Since PREM is based on the adiabatic form of the Adams-Williamson equation, it assumes a well mixed (i.e. homogeneous) composition. This result suggests a lack of heterogeneity in the outermost core due to layering or stagnant convection.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000013936&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMagnetic%2BFlux','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000013936&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMagnetic%2BFlux"><span>Resolving Magnetic Flux Patches at the Surface of the Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>OBrien, Michael S.</p> <p>1996-01-01</p> <p>The geomagnetic field at a given epoch can be used to partition the surface of the liquid outer core into a finite number of contiguous regions in which the radial component of the magnetic flux density, B (sub r), is of one sign. These flux patches are instrumental in providing detail to surface fluid flows inferred from the changing geomagnetic field and in evaluating the validity of the frozen-flux approximation on which such inferences rely. Most of the flux patches in models of the modem field are small and enclose little flux compared to the total unsigned flux emanating from the core. To demonstrate that such patches are not required to explain the most spatially complete and accurate data presently available, those from the Magsat mission, I have constructed a smooth core field model that fits the Magsat data but does not possess small flux patches. I conclude that our present knowledge of the geomagnetic field does not allow us to resolve these features reliably at the core-mantle boundary; thus we possess less information about core flow than previously believed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CMT...tmp...35R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CMT...tmp...35R"><span>Seismic waves and earthquakes in a global monolithic model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roubíček, Tomáš</p> <p>2018-03-01</p> <p>The philosophy that a single "monolithic" model can "asymptotically" replace and couple in a simple elegant way several specialized models relevant on various Earth layers is presented and, in special situations, also rigorously justified. In particular, global seismicity and tectonics is coupled to capture, e.g., (here by a simplified model) ruptures of lithospheric faults generating seismic waves which then propagate through the solid-like mantle and inner core both as shear (S) or pressure (P) waves, while S-waves are suppressed in the fluidic outer core and also in the oceans. The "monolithic-type" models have the capacity to describe all the mentioned features globally in a unified way together with corresponding interfacial conditions implicitly involved, only when scaling its parameters appropriately in different Earth's layers. Coupling of seismic waves with seismic sources due to tectonic events is thus an automatic side effect. The global ansatz is here based, rather for an illustration, only on a relatively simple Jeffreys' viscoelastic damageable material at small strains whose various scaling (limits) can lead to Boger's viscoelastic fluid or even to purely elastic (inviscid) fluid. Self-induced gravity field, Coriolis, centrifugal, and tidal forces are counted in our global model, as well. The rigorous mathematical analysis as far as the existence of solutions, convergence of the mentioned scalings, and energy conservation is briefly presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/864461','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/864461"><span>Emergency core cooling system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Schenewerk, William E.; Glasgow, Lyle E.</p> <p>1983-01-01</p> <p>A liquid metal cooled fast breeder reactor provided with an emergency core cooling system includes a reactor vessel which contains a reactor core comprising an array of fuel assemblies and a plurality of blanket assemblies. The reactor core is immersed in a pool of liquid metal coolant. The reactor also includes a primary coolant system comprising a pump and conduits for circulating liquid metal coolant to the reactor core and through the fuel and blanket assemblies of the core. A converging-diverging venturi nozzle with an intermediate throat section is provided in between the assemblies and the pump. The intermediate throat section of the nozzle is provided with at least one opening which is in fluid communication with the pool of liquid sodium. In normal operation, coolant flows from the pump through the nozzle to the assemblies with very little fluid flowing through the opening in the throat. However, when the pump is not running, residual heat in the core causes fluid from the pool to flow through the opening in the throat of the nozzle and outwardly through the nozzle to the assemblies, thus providing a means of removing decay heat.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10872096','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10872096"><span>Optimization and development of a core-in-cup tablet for modulated release of theophylline in simulated gastrointestinal fluids.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Danckwerts, M P</p> <p>2000-07-01</p> <p>A triple-layer core-in-cup tablet that can release theophylline in simulated gastrointestinal (GI) fluids at three distinct rates has been developed. The first layer is an immediate-release layer; the second layer is a sustained-release layer; and the last layer is a boost layer, which was designed to coincide with a higher nocturnal dose of theophylline. The study consisted of two stages. The first stage optimized the sustained-release layer of the tablet to release theophylline over a period of 12 hr. Results from this stage indicated that 30% w/w acacia gum was the best polymer and concentration to use when compressed to a hardness of 50 N/m2. The second stage of the study involved the investigation of the final triple-layer core-in-cup tablet to release theophylline at three different rates in simulated GI fluids. The triple-layer modulated core-in-cup tablet successfully released drug in simulated fluids at an initial rate of 40 mg/min, followed by a rate of 0.4085 mg/min, in simulated gastric fluid TS, 0.1860 mg/min in simulated intestinal fluid TS, and finally by a boosted rate of 0.6952 mg/min.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDR26008T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDR26008T"><span>Flow of two immiscible fluids in a periodically constricted tube: Transitions to stratified, segmented, churn, spray or segregated flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsamopoulos, John; Fraggedakis, Dimitris; Dimakopoulos, Yiannis</p> <p>2015-11-01</p> <p>We study the flow of two immiscible, Newtonian fluids in a periodically constricted tube driven by a constant pressure gradient. Our Volume-of-Fluid algorithm is used to solve the governing equations. First the code is validated by comparing its predictions to previously reported results for stratified and pulsing flow. Then it is used to capture accurately all the significant topological changes that take place. Initially, the fluids have a core-annular arrangement, which is found to either remain the same or change to a different arrangement depending on the fluid properties, the pressure driving the flow or the flow geometry. The flow-patterns that appear are the core-annular, segmented, churn, spray and segregated flow. The predicted scalings near pinching of the core fluid concur with similarity predictions and earlier numerical results (Cohen et al. (1999)). Flow-pattern maps are constructed in terms of the Reynolds and Weber numbers. Our results provide deeper insights in the mechanism of the pattern transitions and are in agreement with previous studies on core-annular flow (Kouris & Tsamopoulos (2001 & 2002)), segmented flow (Lac & Sherwood (2009)) and churn flow (Bai et al. (1992)). GSRT of Greece through the program ``Excellence'' (Grant No. 1918, entitled ``FilCoMicrA'').</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860014592','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860014592"><span>Constraints on geomagnetic secular variation modeling from electromagnetism and fluid dynamics of the Earth's core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benton, E. R.</p> <p>1986-01-01</p> <p>A spherical harmonic representation of the geomagnetic field and its secular variation for epoch 1980, designated GSFC(9/84), is derived and evaluated. At three epochs (1977.5, 1980.0, 1982.5) this model incorporates conservation of magnetic flux through five selected patches of area on the core/mantle boundary bounded by the zero contours of vertical magnetic field. These fifteen nonlinear constraints are included like data in an iterative least squares parameter estimation procedure that starts with the recently derived unconstrained field model GSFC (12/83). Convergence is approached within three iterations. The constrained model is evaluated by comparing its predictive capability outside the time span of its data, in terms of residuals at magnetic observatories, with that for the unconstrained model.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJP..132..173T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJP..132..173T"><span>Electro-osmotic flow of couple stress fluids in a micro-channel propagated by peristalsis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tripathi, Dharmendra; Yadav, Ashu; Anwar Bég, O.</p> <p>2017-04-01</p> <p>A mathematical model is developed for electro-osmotic peristaltic pumping of a non-Newtonian liquid in a deformable micro-channel. Stokes' couple stress fluid model is employed to represent realistic working liquids. The Poisson-Boltzmann equation for electric potential distribution is implemented owing to the presence of an electrical double layer (EDL) in the micro-channel. Using long wavelength, lubrication theory and Debye-Huckel approximations, the linearized transformed dimensionless boundary value problem is solved analytically. The influence of electro-osmotic parameter (inversely proportional to Debye length), maximum electro-osmotic velocity (a function of external applied electrical field) and couple stress parameter on axial velocity, volumetric flow rate, pressure gradient, local wall shear stress and stream function distributions is evaluated in detail with the aid of graphs. The Newtonian fluid case is retrieved as a special case with vanishing couple stress effects. With increasing the couple stress parameter there is a significant increase in the axial pressure gradient whereas the core axial velocity is reduced. An increase in the electro-osmotic parameter both induces flow acceleration in the core region (around the channel centreline) and it also enhances the axial pressure gradient substantially. The study is relevant in the simulation of novel smart bio-inspired space pumps, chromatography and medical micro-scale devices.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhFl...30c0701P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhFl...30c0701P"><span>Pressure-driven flow of a Herschel-Bulkley fluid with pressure-dependent rheological parameters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panaseti, Pandelitsa; Damianou, Yiolanda; Georgiou, Georgios C.; Housiadas, Kostas D.</p> <p>2018-03-01</p> <p>The lubrication flow of a Herschel-Bulkley fluid in a symmetric long channel of varying width, 2h(x), is modeled extending the approach proposed by Fusi et al. ["Pressure-driven lubrication flow of a Bingham fluid in a channel: A novel approach," J. Non-Newtonian Fluid Mech. 221, 66-75 (2015)] for a Bingham plastic. Moreover, both the consistency index and the yield stress are assumed to be pressure-dependent. Under the lubrication approximation, the pressure at zero order depends only on x and the semi-width of the unyielded core is found to be given by σ(x) = -(1 + 1/n)h(x) + C, where n is the power-law exponent and the constant C depends on the Bingham number and the consistency-index and yield-stress growth numbers. Hence, in a channel of constant width, the width of the unyielded core is also constant, despite the pressure dependence of the yield stress, and the pressure distribution is not affected by the yield-stress function. With the present model, the pressure is calculated numerically solving an integro-differential equation and then the position of the yield surface and the two velocity components are computed using analytical expressions. Some analytical solutions are also derived for channels of constant and linearly varying widths. The lubrication solutions for other geometries are calculated numerically. The implications of the pressure-dependence of the material parameters and the limitations of the method are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...849...30C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...849...30C"><span>Steamworlds: Atmospheric Structure and Critical Mass of Planets Accreting Icy Pebbles</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chambers, John</p> <p>2017-11-01</p> <p>In the core accretion model, gas-giant planets first form a solid core, which then accretes gas from a protoplanetary disk when the core exceeds a critical mass. Here, we model the atmosphere of a core that grows by accreting ice-rich pebbles. The ice fraction of pebbles evaporates in warm regions of the atmosphere, saturating it with water vapor. Excess water precipitates to lower altitudes. Beneath an outer radiative region, the atmosphere is convective, following a moist adiabat in saturated regions due to water condensation and precipitation. Atmospheric mass, density, and temperature increase with core mass. For nominal model parameters, planets with core masses (ice + rock) between 0.08 and 0.16 Earth masses have surface temperatures between 273 and 647 K and form an ocean. In more massive planets, water exists as a supercritical convecting fluid mixed with gas from the disk. Typically, the core mass reaches a maximum (the critical mass) as a function of the total mass when the core is 2-5 Earth masses. The critical mass depends in a complicated way on pebble size, mass flux, and dust opacity due to the occasional appearance of multiple core-mass maxima. The core mass for an atmosphere of 50% hydrogen and helium may be a more robust indicator of the onset of gas accretion. This mass is typically 1-3 Earth masses for pebbles that are 50% ice by mass, increasing with opacity and pebble flux and decreasing with pebble ice/rock ratio.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SMaS...24j5024Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SMaS...24j5024Z"><span>Transient multi-physics analysis of a magnetorheological shock absorber with the inverse Jiles-Atherton hysteresis model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, Jiajia; Li, Yancheng; Li, Zhaochun; Wang, Jiong</p> <p>2015-10-01</p> <p>This paper presents multi-physics modeling of an MR absorber considering the magnetic hysteresis to capture the nonlinear relationship between the applied current and the generated force under impact loading. The magnetic field, temperature field, and fluid dynamics are represented by the Maxwell equations, conjugate heat transfer equations, and Navier-Stokes equations. These fields are coupled through the apparent viscosity and the magnetic force, both of which in turn depend on the magnetic flux density and the temperature. Based on a parametric study, an inverse Jiles-Atherton hysteresis model is used and implemented for the magnetic field simulation. The temperature rise of the MR fluid in the annular gap caused by core loss (i.e. eddy current loss and hysteresis loss) and fluid motion is computed to investigate the current-force behavior. A group of impulsive tests was performed for the manufactured MR absorber with step exciting currents. The numerical and experimental results showed good agreement, which validates the effectiveness of the proposed multi-physics FEA model.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/234259-neutron-radiography-experiments-verification-soluble-boron-mixing-transport-modeling-under-natural-circulation-conditions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/234259-neutron-radiography-experiments-verification-soluble-boron-mixing-transport-modeling-under-natural-circulation-conditions"><span>Neutron radiography experiments for verification of soluble boron mixing and transport modeling under natural circulation conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Feltus, M.A.; Morlang, G.M.</p> <p>1996-06-01</p> <p>The use of neutron radiography for visualization of fluid flow through flow visualization modules has been very successful. Current experiments at the Penn State Breazeale Reactor serve to verify the mixing and transport of soluble boron under natural flow conditions as would be experienced in a pressurized water reactor. Different flow geometries have been modeled including holes, slots, and baffles. Flow modules are constructed of aluminum box material 1 1/2 inches by 4 inches in varying lengths. An experimental flow system was built which pumps fluid to a head tank and natural circulation flow occurs from the head tank throughmore » the flow visualization module to be radiographed. The entire flow system is mounted on a portable assembly to allow placement of the flow visualization module in front of the neutron beam port. A neutron-transparent fluorinert fluid is used to simulate water at different densities. Boron is modeled by gadolinium oxide powder as a tracer element, which is placed in a mixing assembly and injected into the system by remote operated electric valve, once the reactor is at power. The entire sequence is recorded on real-time video. Still photographs are made frame-by-frame from the video tape. Computers are used to digitally enhance the video and still photographs. The data obtained from the enhancement will be used for verification of simple geometry predictions using the TRAC and RELAP thermal-hydraulic codes. A detailed model of a reactor vessel inlet plenum, downcomer region, flow distribution area and core inlet is being constructed to model the AP600 plenum. Successive radiography experiments of each section of the model under identical conditions will provide a complete vessel/core model for comparison with the thermal-hydraulic codes.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H12C..04T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H12C..04T"><span>Experimental observation and numerical simulation of permeability changes in dolomite at CO2 sequestration conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tutolo, B. M.; Luhmann, A. J.; Kong, X.; Saar, M. O.; Seyfried, W. E.</p> <p>2013-12-01</p> <p>Injecting surface temperature CO2 into geothermally warm reservoirs for geologic storage or energy production may result in depressed temperature near the injection well and thermal gradients and mass transfer along flow paths leading away from the well. Thermal gradients are particularly important to consider in reservoirs containing carbonate minerals, which are more soluble at lower temperatures, as well as in CO2-based geothermal energy reservoirs where lowering heat exchanger rejection temperatures increases efficiency. Additionally, equilibrating a fluid with cation-donating silicates near a low-temperature injection well and transporting the fluid to higher temperature may enhance the kinetics of mineral precipitation in such a way as to overcome the activation energy required for mineral trapping of CO2. We have investigated this process by subjecting a dolomite core to a 650-hour temperature series experiment in which the fluid was saturated with CO2 at high pressure (110-126 bars) and 21°C. This fluid was recirculated through the dolomite core, increasing permeability from 10-16 to 10-15.2 m2. Subsequently, the core temperature was raised to 50° C, and permeability decreased to 10-16.2 m2 after 289 hours, due to thermally-driven CO2 exsolution. Increasing core temperature to 100°C for the final 145 hours of the experiment caused dolomite to precipitate, which, together with further CO2 exsolution, decreased permeability to 10-16.4 m2. Post-experiment x-ray computed tomography and scanning electron microscope imagery of the dolomite core reveals abundant matrix dissolution and enlargement of flow paths at low temperatures, and subsequent filling-in of the passages at elevated temperature by dolomite. To place this experiment within the broader context of geologic CO2 sequestration, we designed and utilized a reactive transport simulator that enables dynamic calculation of CO2 equilibrium constants and fugacity and activity coefficients by incorporating mineral, fluid, and aqueous species equations of state into its structure. Phase equilibria calculations indicate that fluids traveling away from the depressed temperature zone near the injection well may exsolve and precipitate up to 200 cc CO2, 1.45 cc dolomite, and 2.3 cc calcite, per kg, but we use the reactive transport simulator to place more realistic limits on these calculations. The simulations show that thermally-induced CO2 exsolution creates velocity gradients within the modeled domain, leading to increased velocities at lower pressure due to the increasingly gas-like density of CO2. Because dolomite precipitation kinetics strongly depend on temperature, modeled dolomite precipitation effectively concentrates within high temperature regions, while calcite precipitation is predicted to occur over a broader range. Additionally, because the molar volume of dolomite is almost double that of calcite, transporting a low temperature, dolomite-saturated fluid across a thermal gradient can lead to more substantial pore space clogging. We conclude that injecting cool CO2 into geothermally warm reservoirs may substantially alter formation porosity, permeability, and injectivity, and can result in favorable conditions for permanent storage of CO2 as a solid carbonate phase.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1112182V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1112182V"><span>Static Grain Growth in Contact Metamorphic Calcite: A Cathodoluminescence Study.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vogt, B.; Heilbronner, R.; Herwegh, M.; Ramseyer, K.</p> <p>2009-04-01</p> <p>In the Adamello contact aureole, monomineralic mesozoic limestones were investigated in terms of grain size evolution and compared to results on numerical modeling performed by Elle. The sampled area shows no deformation and therefore represents an appropriate natural laboratory for the study of static grain growth (Herwegh & Berger, 2003). For this purpose, samples were collected at different distances to the contact to the pluton, covering a temperature range between 270 to 630°C. In these marbles, the grain sizes increase with temperature from 5 µm to about 1 cm as one approaches the contact (Herwegh & Berger, 2003). In some samples, photomicrographs show domains of variable cathodoluminescence (CL) intensities, which are interpreted to represent growth zonations. Microstructures show grains that contain cores and in some samples even several growth stages. The cores are usually not centered and the zones not concentric. They may be in touch with grain boundaries. These zonation patterns are consistent within a given aggregate but differ among the samples even if they come from the same location. Relative CL intensities depend on the Mn/Fe ratio. We assume that changes in trace amounts of Mn/Fe must have occurred during the grain size evolution, preserving local geochemical trends and their variations with time. Changes in Mn/Fe ratios can either be explained by (a) locally derived fluids (e.g. hydration reactions of sheet silicate rich marbles in the vicinity) or (b) by the infiltration of the calcite aggregates by externally derived (magmatic?) fluids. At the present stage, we prefer a regional change in fluid composition (b) because the growth zonations only occur at distances of 750-1250 m from the pluton contact (350-450°C). Closer to the contact, neither zonations nor cores were found. At larger distances, CL intensities differ from grain to grain, revealing diagenetic CL patterns that were incompletely recrystallized by grain growth. The role of infiltration of magmatic fluids is also manifest in the vicinity of dikes, where intense zonation patterns are prominent in the marbles. The software Elle was developed to simulate microstructural evolution in rocks. The numerical model with the title "Grain boundary sweeping" was performed by M. Jessell and was found on http://www.materialsknowledge.org/elle. It displays the grain size evolution and the development of growth zonations during grain boundary migration of a 2D foam structure. This simulation was chosen because the driving force is the minimization of isotropic surface energies. It will be compared to the natural microstructures. At the last stage of the simulation the average grain and core sizes have increased. All, even the smallest grains, show growth zonations. Grains can be divided into two groups: (a) initially larger grains, increasing their grain size and maintaining their core size and (b) initially smaller grains with decreasing grain and decreasing core size. Group (a) grains show large areas swept by grain boundaries into the direction of small grains. Grain boundaries between large grains move more slowly. Their cores do not touch any grain boundaries. Cores of group (b) grains are in contact with the grain boundary network and are on the way to be consumed. In the numerical model and in the natural example similar features can be observed: The cores are not necessarily centered, the zonations are not necessarily concentric and some of the cores touch the grain boundary network. In the simulation, grain boundary migration velocity between large grains is smaller than between a large and a small grain. From this we would predict that - given enough time - a well sorted grain size distribution of increased grain size could be generated. But since many small grains occur we infer that this equilibrium has not been obtained. Analytical results of some natural samples that could be analyzed up to now indicate a relatively well sorted grain size distribution suggesting a more mature state of static grain growth. In comparison to the simulation, grain and core boundaries in the marbles are not always straight. For lobate grain boundaries the surface area has not been minimized in respect to the grain size. An explanation for this might be grain boundary pinning or a local dynamic overprint. Some cores and growth zones in the investigated calcites show a continuous change in luminescence. This is interpreted to be an effect of late diffusion within the grain and/or a continuous change of fluid composition and supply. The absence of zonation in samples close to the contact might be explained by fast grain growth due to high temperatures and/or fast fluid transport. Possibly, this is combined with an enhanced component of volume diffusion. Thus concentration variations of Mn/Fe are diminished and not visible in form of a growth zonation. Herwegh M, Berger A (2003) Differences in grain growth of calcite: a field-based modeling approach. Contr. Min. Pet. 145: 600-611</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JFM...592...23S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JFM...592...23S"><span>Stability of miscible core?annular flows with viscosity stratification</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Selvam, B.; Merk, S.; Govindarajan, Rama; Meiburg, E.</p> <p></p> <p>The linear stability of variable viscosity, miscible core-annular flows is investigated. Consistent with pipe flow of a single fluid, the flow is stable at any Reynolds number when the magnitude of the viscosity ratio is less than a critical value. This is in contrast to the immiscible case without interfacial tension, which is unstable at any viscosity ratio. Beyond the critical value of the viscosity ratio, the flow can be unstable even when the more viscous fluid is in the core. This is in contrast to plane channel flows with finite interface thickness, which are always stabilized relative to single fluid flow when the less viscous fluid is in contact with the wall. If the more viscous fluid occupies the core, the axisymmetric mode usually dominates over the corkscrew mode. It is demonstrated that, for a less viscous core, the corkscrew mode is inviscidly unstable, whereas the axisymmetric mode is unstable for small Reynolds numbers at high Schmidt numbers. For the parameters under consideration, the switchover occurs at an intermediate Schmidt number of about 500. The occurrence of inviscid instability for the corkscrew mode is shown to be consistent with the Rayleigh criterion for pipe flows. In some parameter ranges, the miscible flow is seen to be more unstable than its immiscible counterpart, and the physical reasons for this behaviour are discussed.A detailed parametric study shows that increasing the interface thickness has a uniformly stabilizing effect. The flow is least stable when the interface between the two fluids is located at approximately 0.6 times the tube radius. Unlike for channel flow, there is no sudden change in the stability with radial location of the interface. The instability originates mainly in the less viscous fluid, close to the interface.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863342','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863342"><span>Magnetic nuclear core restraint and control</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Cooper, Martin H.</p> <p>1979-01-01</p> <p>A lateral restraint and control system for a nuclear reactor core adaptable to provide an inherent decrease of core reactivity in response to abnormally high reactor coolant fluid temperatures. An electromagnet is associated with structure for radially compressing the core during normal reactor conditions. A portion of the structures forming a magnetic circuit are composed of ferromagnetic material having a curie temperature corresponding to a selected coolant fluid temperature. Upon a selected signal, or inherently upon a preselected rise in coolant temperature, the magnetic force is decreased a given amount sufficient to relieve the compression force so as to allow core radial expansion. The expanded core configuration provides a decreased reactivity, tending to shut down the nuclear reaction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863245','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863245"><span>Magnetic nuclear core restraint and control</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Cooper, Martin H.</p> <p>1978-01-01</p> <p>A lateral restraint and control system for a nuclear reactor core adaptable to provide an inherent decrease of core reactivity in response to abnormally high reactor coolant fluid temperatures. An electromagnet is associated with structure for radially compressing the core during normal reactor conditions. A portion of the structures forming a magnetic circuit are composed of ferromagnetic material having a curie temperature corresponding to a selected coolant fluid temperature. Upon a selected signal, or inherently upon a preselected rise in coolant temperature, the magnetic force is decreased a given amount sufficient to relieve the compression force so as to allow core radial expansion. The expanded core configuration provides a decreased reactivity, tending to shut down the nuclear reaction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21219514','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21219514"><span>A systematic review of randomised controlled trials of the effects of warmed irrigation fluid on core body temperature during endoscopic surgeries.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Yinghui; Tian, Jinhui; Sun, Mei; Yang, Kehu</p> <p>2011-02-01</p> <p>The purpose of this systematic review was to establish whether warmed irrigation fluid temperature could decrease the drop of body temperature and incidence of shivering and hypothermia. Irrigation fluid, which is used in large quantities during endoscopic surgeries at room temperature, is considered to be associated with hypothermia and shivering. It remains controversial whether using warmed irrigation fluid to replace room-temperature irrigation fluid will decrease the drop of core body temperature and the occurrence of hypothermia. A comprehensive search (computerised database searches, footnote chasing, citation chasing) was undertaken to identify all the randomised controlled trials that explored temperature of irrigation fluid in endoscopic surgery. An approach involving meta-analysis was used. We searched PubMed, EMBASE, Cochrane Library, SCI, China academic journals full-text databases, Chinese Biomedical Literature Database, Chinese scientific journals databases and Chinese Medical Association Journals for trials that meet the inclusion criteria. Study quality was assessed using standards recommended by Cochrane Library Handbook 5.0.1. Disagreement was resolved by consensus. Thirteen randomised controlled trials including 686 patients were identified. The results showed that room-temperature irrigation fluid caused a greater drop of core body temperature in patients, compared to warmed irrigation fluid (p < 0.00001; I(2) = 85%). The occurrence of shivering [odds ratio (OR) 5.13, 95% CI: 2.95-10.19, p < 0.00001; I(2) = 0%] and hypothermia (OR 22.01, 95% CI: 2.03-197.08, p = 0.01; I(2) = 64%) in the groups having warmed irrigation fluid were lower than the group of studies having room-temperature fluid. In endoscopic surgeries, irrigation fluid is recommended to be warmed to decrease the drop of core body temperature and the risk of perioperative shivering and hypothermia. Warming irrigating fluid should be considered standard practice in all endoscopic surgeries. © 2011 Blackwell Publishing Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830053503&hterms=goethe&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgoethe','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830053503&hterms=goethe&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgoethe"><span>Magnetism and thermal evolution of the terrestrial planets</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stevenson, D. J.; Spohn, T.; Schubert, G.</p> <p>1983-01-01</p> <p>The absence in the cases of Venus and Mars of the substantial intrinsic magnetic fields of the earth and Mercury is considered, in light of thermal history calculations which suggest that, while the cores of Mercury and the earth are continuing to freeze, the cores of Venus and Mars may still be completely liquid. It is noted that completely fluid cores, lacking intrinsic heat sources, are not likely to sustain thermal convection for the age of the solar system, but cool to a subadiabatic, conductive state that cannot maintain a dynamo because of the gravitational energy release and the chemically driven convection that accompany inner core growth. The models presented include realistic pressure- and composition-dependent freezing curves for the core, and material parameters are chosen so that correct present-day values of heat outflow, upper mantle temperature and viscosity, and inner core radius, are obtained for the earth.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H43M..03J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H43M..03J"><span>Incorporating the Impacts of Small Scale Rock Heterogeneity into Models of Flow and Trapping in Target UK CO2 Storage Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jackson, S. J.; Reynolds, C.; Krevor, S. C.</p> <p>2017-12-01</p> <p>Predictions of the flow behaviour and storage capacity of CO2 in subsurface reservoirs are dependent on accurate modelling of multiphase flow and trapping. A number of studies have shown that small scale rock heterogeneities have a significant impact on CO2flow propagating to larger scales. The need to simulate flow in heterogeneous reservoir systems has led to the development of numerical upscaling techniques which are widely used in industry. Less well understood, however, is the best approach for incorporating laboratory characterisations of small scale heterogeneities into models. At small scales, heterogeneity in the capillary pressure characteristic function becomes significant. We present a digital rock workflow that combines core flood experiments with numerical simulations to characterise sub-core scale capillary pressure heterogeneities within rock cores from several target UK storage reservoirs - the Bunter, Captain and Ormskirk sandstone formations. Measured intrinsic properties (permeability, capillary pressure, relative permeability) and 3D saturations maps from steady-state core flood experiments were the primary inputs to construct a 3D digital rock model in CMG IMEX. We used vertical end-point scaling to iteratively update the voxel by voxel capillary pressure curves from the average MICP curve; with each iteration more closely predicting the experimental saturations and pressure drops. Once characterised, the digital rock cores were used to predict equivalent flow functions, such as relative permeability and residual trapping, across the range of flow conditions estimated to prevail in the CO2 storage reservoirs. In the case of the Captain sandstone, rock cores were characterised across an entire 100m vertical transect of the reservoir. This allowed analysis of the upscaled impact of small scale heterogeneity on flow and trapping. Figure 1 shows the varying degree to which heterogeneity impacted flow depending on the capillary number in the Captain sandstone. At low capillary numbers, typical of regions where flow is dominated by buoyancy, fluid flow is impeded and trapping enhanced. At high capillary numbers, typical of the near wellbore environment, the fluid distributed homogeneously and the equivalent relative permeability was higher leading to improved injectivity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SMaS...26h5014B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SMaS...26h5014B"><span>Design and dynamic modeling of electrorheological fluid-based variable-stiffness fin for robotic fish</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bazaz Behbahani, Sanaz; Tan, Xiaobo</p> <p>2017-08-01</p> <p>Fish actively control their stiffness in different swimming conditions. Inspired by such an adaptive behavior, in this paper we study the design, prototyping, and dynamic modeling of compact, tunable-stiffness fins for robotic fish, where electrorheological (ER) fluid serves as the enabling element. A multi-layer composite fin with an ER fluid core is prototyped and utilized to investigate the influence of electrical field on its performance. Hamilton's principle is used to derive the dynamic equations of motion of the flexible fin, and Lighthill's large-amplitude elongated-body theory is adopted to estimate the hydrodynamic force when the fin undergoes base-actuated rotation. The dynamic equations are then discretized using the finite element method, to obtain an approximate numerical solution. Experiments are conducted on the prototyped flexible ER fluid-filled beam for parameter identification and validation of the proposed model, and for examining the effectiveness of electrically controlled stiffness tuning. In particular, it is found that the natural frequency is increased by almost 40% when the applied electric field changes from 0 to 1.5× {10}6 {{V}} {{{m}}}-1.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SolE....9..683W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SolE....9..683W"><span>Permeability and seismic velocity anisotropy across a ductile-brittle fault zone in crystalline rock</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wenning, Quinn C.; Madonna, Claudio; de Haller, Antoine; Burg, Jean-Pierre</p> <p>2018-05-01</p> <p>This study characterizes the elastic and fluid flow properties systematically across a ductile-brittle fault zone in crystalline rock at the Grimsel Test Site underground research laboratory. Anisotropic seismic velocities and permeability measured every 0.1 m in the 0.7 m across the transition zone from the host Grimsel granodiorite to the mylonitic core show that foliation-parallel P- and S-wave velocities systematically increase from the host rock towards the mylonitic core, while permeability is reduced nearest to the mylonitic core. The results suggest that although brittle deformation has persisted in the recent evolution, antecedent ductile fabric continues to control the matrix elastic and fluid flow properties outside the mylonitic core. The juxtaposition of the ductile strain zone next to the brittle zone, which is bounded inside the two mylonitic cores, causes a significant elastic, mechanical, and fluid flow heterogeneity, which has important implications for crustal deformation and fluid flow and for the exploitation and use of geothermal energy and geologic waste storage. The results illustrate how physical characteristics of faults in crystalline rocks change in fault zones during the ductile to brittle transitions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V43G2941D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V43G2941D"><span>Listvenite formation from peridotite: Insights from Oman Drilling Project hole BT1B and preliminary reaction path model approach.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Obeso, J. C.; Kelemen, P. B.; Manning, C. E.; Michibayashi, K.; Harris, M.</p> <p>2017-12-01</p> <p>Oman Drilling Project hole BT1B drilled 300 meters through the basal thrust of the Samail ophiolite. The first 200 meters of this hole are dominated by listvenites (completely carbonated peridotites) and serpentinites. Below 200 meters the hole is mainly composed of metasediments and metavolcanics. This core provides a unique record of interaction between (a) mantle peridotite in the leading edge of the mantle wedge and (b) hydrous, CO2 rich fluids derived from subducting lithologies similar to those in the metamorphic sole. We used EQ3/6 to simulate a reaction path in which hydrous fluid in equilibrium with qtz + calcite + feldspar + chlorite or smectite reacts with initially fresh peridotite at 100°C (the estimated temperature of alteration, Falk & Kelemen GCA 2015) and 5 kb. Water was first equilibrated with minerals observed during core description in the metamorphic sole at 100°C and 5kb. This fluid is then reacted with olivine enstatite and diopside (Mg#90) approximating the average composition of residual mantle peridotite (harzburgite) in Oman. Secondary minerals resulting from complete reaction are then reacted again with the initial fluid in an iterative process, up to water/rock > 1000. Water/rock close to 1 results in complete serpentinization of the peridotite, with chrysotile, brucite and magnetite as the only minerals. Water/rock >10 produces carbonates, chlorite and talc. Further increasing water/rock to > 100 produces assemblages dominated by carbonates and quartz with minor muscovite, similar to listvenites of hole BT1B that contain qtz + carbonates + Fe-oxyhydroxides + relict spinel ± chromian muscovite and fuchsite. The results of this preliminary model are consistent with the complex veining history of core from BT1B, with carbonate/iron oxide veins in both listvenites and serpentinites interpreted to be the earliest record of peridotite carbonation after initial serpentinization.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27052741','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27052741"><span>Efficacy of intravenous fluid warming during goal-directed fluid therapy in patients undergoing laparoscopic colorectal surgery: a randomized controlled trial.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Choi, Ji-Won; Kim, Duk-Kyung; Lee, Seung-Won; Park, Jung-Bo; Lee, Gyu-Hong</p> <p>2016-06-01</p> <p>To evaluate the clinical efficacy of intravenous (IV) fluid warming in patients undergoing laparoscopic colorectal surgery. Adult patients undergoing laparoscopic colorectal surgery were randomly assigned to receive either IV fluids at room temperature (control group) or warmed IV fluids (warm fluids group). Each patient received a standardized goal-directed fluid regimen based on stroke volume variances. Oesophageal temperature was measured at 15 min intervals for 2 h after induction of anaesthesia. A total of 52 patients were enrolled in the study. The drop in core temperature in the warm fluids group was significantly less than in the control group 2 h after the induction of anaesthesia. This significant difference was seen from 30 min after induction. IV fluid warming was associated with a smaller drop in core temperature than room temperature IV fluids in laparoscopic colorectal surgery incorporating goal-directed fluid therapy. © The Author(s) 2016.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810012884','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810012884"><span>Investigation of geomagnetic field forecasting and fluid dynamics of the core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benton, E. R. (Principal Investigator)</p> <p>1981-01-01</p> <p>The discovery of simple, theoretically sound upper limits for geomagnetic moments (dipole, quadrupole, etc.) provides a significant use of MAGSAT data, establishes useful constraints for future magnetic models, and bears strongly on the probable time required before the next polarity reversal can occur. The field models of MAGSAT data are of prime use and are highly suitable as supplied to date.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PEPI..276..134W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PEPI..276..134W"><span>Experiments on fragmentation and thermo-chemical exchanges during planetary core formation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wacheul, Jean-Baptiste; Le Bars, Michael</p> <p>2018-03-01</p> <p>The initial thermo-chemical state of telluric planets was largely controlled by mixing following the collision of differentiated proto-planets. Up to now, most models of planet formation simply assume that the iron core of the impactors immediately broke up to form an "iron rain" within a large-scale magma ocean, leading to the rapid equilibration of the whole metal with the whole mantle. Only recent studies have focused on resolving the fluid mechanics of the problem, with the aim to define more relevant diffusion-advection models of thermal and chemical exchanges within and between the two fluids. Furthermore, the influence of the viscosity ratio on this dynamical process is generally neglected, whilst it is known to play a role in the breakup of the initial iron diapirs and in the shape of the resulting droplets. Here we report the results of analog laboratory experiments matching the dynamical regime of the geophysical configuration. High speed video recording allows us to describe and characterize the fluid dynamics of the system, and temperature measurements allow us to quantify the diffusive exchanges integrated during the fall of the liquid metal. We find that the early representation of this flow as an iron rain is far from the experimental results. The equilibration coefficient at a given depth depends both on the initial size of the metal diapir and on the viscosity of the ambient fluid, whereas the falling speed is only controlled by the initial size. Various scalings for the diffusive exchanges coming from the literature are tested. We find good agreement with the turbulent thermal model developed by Deguen et al. (2014).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/270485','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/270485"><span>A novel enzyme-based acidizing system: Matrix acidizing and drilling fluid damage removal</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Harris, R.E.; McKay, D.M.; Moses, V.</p> <p>1995-12-31</p> <p>A novel acidizing process is used to increase the permeability of carbonate rock cores in the laboratory and to remove drilling fluid damage from cores and wafers. Field results show the benefits of the technology as applied both to injector and producer wells.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050234624&hterms=reproduction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dreproduction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050234624&hterms=reproduction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dreproduction"><span>Multiphysics Nuclear Thermal Rocket Thrust Chamber Analysis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Ten-See</p> <p>2005-01-01</p> <p>The objective of this effort is t o develop an efficient and accurate thermo-fluid computational methodology to predict environments for hypothetical thrust chamber design and analysis. The current task scope is to perform multidimensional, multiphysics analysis of thrust performance and heat transfer analysis for a hypothetical solid-core, nuclear thermal engine including thrust chamber and nozzle. The multiphysics aspects of the model include: real fluid dynamics, chemical reactivity, turbulent flow, and conjugate heat transfer. The model will be designed to identify thermal, fluid, and hydrogen environments in all flow paths and materials. This model would then be used to perform non- nuclear reproduction of the flow element failures demonstrated in the Rover/NERVA testing, investigate performance of specific configurations and assess potential issues and enhancements. A two-pronged approach will be employed in this effort: a detailed analysis of a multi-channel, flow-element, and global modeling of the entire thrust chamber assembly with a porosity modeling technique. It is expected that the detailed analysis of a single flow element would provide detailed fluid, thermal, and hydrogen environments for stress analysis, while the global thrust chamber assembly analysis would promote understanding of the effects of hydrogen dissociation and heat transfer on thrust performance. These modeling activities will be validated as much as possible by testing performed by other related efforts.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V31B4738I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V31B4738I"><span>Refining the Subseafloor Circulation Model of the Middle Valley Hydrothermal System Using Fluid Geochemistry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Inderbitzen, K. E.; Wheat, C. G.; Baker, P. A.; Fisher, A. T.</p> <p>2014-12-01</p> <p>Currently, fluid circulation patterns and the evolution of rock/fluid compositions as circulation occurs in subseafloor hydrothermal systems are poorly constrained. Sedimented spreading centers provide a unique opportunity to study subsurface flow because sediment acts as an insulating blanket that traps heat from the cooling magma body and limits: (a) potential flow paths for seawater to recharge the aquifer in permeable upper basaltic basement and (b) points of altered fluid egress. This also allows for a range of thermal and geochemical gradients to exist near the sediment-water interface. Models of fluid circulation patterns in this type of hydrologic setting have been generated (eg. Stein and Fisher, 2001); however fluid chemistry datasets have not previously been used to test the model's viability. We address this issue by integrating the existing circulation model with fluid compositional data collected from sediment pore waters and high temperature hydrothermal vents located in Middle Valley on the Juan de Fuca Ridge. Middle Valley hosts a variety of hydrologic regimes: including areas of fluid recharge (Site 855), active venting (Site 858/1036; Dead Dog vent field), recent venting (Site 856/1035; Bent Hill Massive Sulfide deposit) and a section of heavily sedimented basement located between recharge and discharge sites (Site 857). We will present new results based on thermal and geochemical data from the area of active venting (Sites 858 and 1036), that was collected during Ocean Drilling Program Legs 139 and 169 and a subsequent heat flow/gravity coring effort. These results illuminate fine scale controls on secondary recharge and fluid flow within the sediment section at Site 858/1036. The current status of high temperature vents in this area (based on observations made in July, 2014) will also be outlined.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoJI.196.1544A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoJI.196.1544A"><span>Self-induced seismicity due to fluid circulation along faults</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aochi, Hideo; Poisson, Blanche; Toussaint, Renaud; Rachez, Xavier; Schmittbuhl, Jean</p> <p>2014-03-01</p> <p>In this paper, we develop a system of equations describing fluid migration, fault rheology, fault thickness evolution and shear rupture during a seismic cycle, triggered either by tectonic loading or by fluid injection. Assuming that the phenomena predominantly take place on a single fault described as a finite permeable zone of variable width, we are able to project the equations within the volumetric fault core onto the 2-D fault interface. From the basis of this `fault lubrication approximation', we simulate the evolution of seismicity when fluid is injected at one point along the fault to model-induced seismicity during an injection test in a borehole that intercepts the fault. We perform several parametric studies to understand the basic behaviour of the system. Fluid transmissivity and fault rheology are key elements. The simulated seismicity generally tends to rapidly evolve after triggering, independently of the injection history and end when the stationary path of fluid flow is established at the outer boundary of the model. This self-induced seismicity takes place in the case where shear rupturing on a planar fault becomes dominant over the fluid migration process. On the contrary, if healing processes take place, so that the fluid mass is trapped along the fault, rupturing occurs continuously during the injection period. Seismicity and fluid migration are strongly influenced by the injection rate and the heterogeneity.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptFT..43...35S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptFT..43...35S"><span>Optical fiber F-P magnetic field sensor based on magnetostrictive effect of magnetic fluid</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Fuquan; Luo, Yan; Che, Jiajia; Ren, Zhijun; peng, Baojin</p> <p>2018-07-01</p> <p>magnetic field sensor of air-gap Fabry-Perot fiber interferometersis proposed based on magnetostrictive effect. The sensor is consisted of single-model fiber (SMF), air-gap, no-core fiber (NCF) and magnetic fluid. Those are sealed in the capillary, SMF and NCF are connect with air chamber and magnetic fluid column. With the presence of an external magnetic field, air chamber cavity length changes because of the magneto-volume variation of magnetic fluids. This situation causes a change in the optical path difference. Detection of the drift of interference spectrum leads to the detection of the change in magnetic field. When the magnetic field is parallel to the direction in which the capillary is placed, the sensitivity is 0.2347 nm/mT; when the magnetic fluid is perpendicular to the direction in which the capillary is placed, the sensitivity is 0.325 nm/http://mT.%20In.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8170337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8170337"><span>Quantification of oil and water in preserved reservoir rock by NMR spectroscopy and imaging.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Davies, S; Hardwick, A; Roberts, D; Spowage, K; Packer, K J</p> <p>1994-01-01</p> <p>Reservoir rock analysis by proton NMR requires separation of the response into brine and crude oil components. Tests on preserved core from a North Sea chalk reservoir show that spin-lattice relaxation time distributions can be used to distinguish the two fluids. NMR estimates of oil and water saturations for 1.5" diameter core examined in a 10 MHz Bruker Minispec spectrometer closely match fluid contents determined by distillation. The spin-lattice relaxation contrast mechanism developed for core samples can be applied in the quantitative analysis of NMR images. The relaxation data are compared with data from chemical shift imaging on the same core sample. The results indicate that it will be possible to monitor changes in fluid distributions, in this and similar systems, under dynamic conditions such as in a waterflood.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25924080','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25924080"><span>Methanogenic archaea in marcellus shale: a possible mechanism for enhanced gas recovery in unconventional shale resources.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tucker, Yael Tarlovsky; Kotcon, James; Mroz, Thomas</p> <p>2015-06-02</p> <p>Marcellus Shale occurs at depths of 1.5-2.5 km (5000 to 8000 feet) where most geologists generally assume that thermogenic processes are the only source of natural gas. However, methanogens in produced fluids and isotopic signatures of biogenic methane in this deep shale have recently been discovered. This study explores whether those methanogens are indigenous to the shale or are introduced during drilling and hydraulic fracturing. DNA was extracted from Marcellus Shale core samples, preinjected fluids, and produced fluids and was analyzed using Miseq sequencing of 16s rRNA genes. Methanogens present in shale cores were similar to methanogens in produced fluids. No methanogens were detected in injected fluids, suggesting that this is an unlikely source and that they may be native to the shale itself. Bench-top methane production tests of shale core and produced fluids suggest that these organisms are alive and active under simulated reservoir conditions. Growth conditions designed to simulate the hydrofracture processes indicated somewhat increased methane production; however, fluids alone produced relatively little methane. Together, these results suggest that some biogenic methane may be produced in these wells and that hydrofracture fluids currently used to stimulate gas recovery could stimulate methanogens and their rate of producing methane.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3820981','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3820981"><span>The first microbiological contamination assessment by deep-sea drilling and coring by the D/V Chikyu at the Iheya North hydrothermal field in the Mid-Okinawa Trough (IODP Expedition 331)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yanagawa, Katsunori; Nunoura, Takuro; McAllister, Sean M.; Hirai, Miho; Breuker, Anja; Brandt, Leah; House, Christopher H.; Moyer, Craig L.; Birrien, Jean-Louis; Aoike, Kan; Sunamura, Michinari; Urabe, Tetsuro; Mottl, Michael J.; Takai, Ken</p> <p>2013-01-01</p> <p>During the Integrated Ocean Drilling Program (IODP) Expedition 331 at the Iheya North hydrothermal system in the Mid-Okinawa Trough by the D/V Chikyu, we conducted microbiological contamination tests of the drilling and coring operations. The contamination from the drilling mud fluids was assessed using both perfluorocarbon tracers (PFT) and fluorescent microsphere beads. PFT infiltration was detected from the periphery of almost all whole round cores (WRCs). By contrast, fluorescent microspheres were not detected in hydrothermally active core samples, possibly due to thermal decomposition of the microspheres under high-temperature conditions. Microbial contamination from drilling mud fluids to the core interior subsamples was further characterized by molecular-based evaluation. The microbial 16S rRNA gene phylotype compositions in the drilling mud fluids were mainly composed of sequences of Beta- and Gammaproteobacteria, and Bacteroidetes and not archaeal sequences. The phylotypes that displayed more than 97% similarity to the sequences obtained from the drilling mud fluids were defined as possible contaminants in this study and were detected as minor components of the bacterial phylotype compositions in 13 of 37 core samples. The degree of microbiological contamination was consistent with that determined by the PFT and/or microsphere assessments. This study suggests a constructive approach for evaluation and eliminating microbial contamination during riser-less drilling and coring operations by the D/V Chikyu. PMID:24265628</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24265628','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24265628"><span>The first microbiological contamination assessment by deep-sea drilling and coring by the D/V Chikyu at the Iheya North hydrothermal field in the Mid-Okinawa Trough (IODP Expedition 331).</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yanagawa, Katsunori; Nunoura, Takuro; McAllister, Sean M; Hirai, Miho; Breuker, Anja; Brandt, Leah; House, Christopher H; Moyer, Craig L; Birrien, Jean-Louis; Aoike, Kan; Sunamura, Michinari; Urabe, Tetsuro; Mottl, Michael J; Takai, Ken</p> <p>2013-01-01</p> <p>During the Integrated Ocean Drilling Program (IODP) Expedition 331 at the Iheya North hydrothermal system in the Mid-Okinawa Trough by the D/V Chikyu, we conducted microbiological contamination tests of the drilling and coring operations. The contamination from the drilling mud fluids was assessed using both perfluorocarbon tracers (PFT) and fluorescent microsphere beads. PFT infiltration was detected from the periphery of almost all whole round cores (WRCs). By contrast, fluorescent microspheres were not detected in hydrothermally active core samples, possibly due to thermal decomposition of the microspheres under high-temperature conditions. Microbial contamination from drilling mud fluids to the core interior subsamples was further characterized by molecular-based evaluation. The microbial 16S rRNA gene phylotype compositions in the drilling mud fluids were mainly composed of sequences of Beta- and Gammaproteobacteria, and Bacteroidetes and not archaeal sequences. The phylotypes that displayed more than 97% similarity to the sequences obtained from the drilling mud fluids were defined as possible contaminants in this study and were detected as minor components of the bacterial phylotype compositions in 13 of 37 core samples. The degree of microbiological contamination was consistent with that determined by the PFT and/or microsphere assessments. This study suggests a constructive approach for evaluation and eliminating microbial contamination during riser-less drilling and coring operations by the D/V Chikyu.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960047459','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960047459"><span>A Computational Fluid Dynamic and Heat Transfer Model for Gaseous Core and Gas Cooled Space Power and Propulsion Reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anghaie, S.; Chen, G.</p> <p>1996-01-01</p> <p>A computational model based on the axisymmetric, thin-layer Navier-Stokes equations is developed to predict the convective, radiation and conductive heat transfer in high temperature space nuclear reactors. An implicit-explicit, finite volume, MacCormack method in conjunction with the Gauss-Seidel line iteration procedure is utilized to solve the thermal and fluid governing equations. Simulation of coolant and propellant flows in these reactors involves the subsonic and supersonic flows of hydrogen, helium and uranium tetrafluoride under variable boundary conditions. An enthalpy-rebalancing scheme is developed and implemented to enhance and accelerate the rate of convergence when a wall heat flux boundary condition is used. The model also incorporated the Baldwin and Lomax two-layer algebraic turbulence scheme for the calculation of the turbulent kinetic energy and eddy diffusivity of energy. The Rosseland diffusion approximation is used to simulate the radiative energy transfer in the optically thick environment of gas core reactors. The computational model is benchmarked with experimental data on flow separation angle and drag force acting on a suspended sphere in a cylindrical tube. The heat transfer is validated by comparing the computed results with the standard heat transfer correlations predictions. The model is used to simulate flow and heat transfer under a variety of design conditions. The effect of internal heat generation on the heat transfer in the gas core reactors is examined for a variety of power densities, 100 W/cc, 500 W/cc and 1000 W/cc. The maximum temperature, corresponding with the heat generation rates, are 2150 K, 2750 K and 3550 K, respectively. This analysis shows that the maximum temperature is strongly dependent on the value of heat generation rate. It also indicates that a heat generation rate higher than 1000 W/cc is necessary to maintain the gas temperature at about 3500 K, which is typical design temperature required to achieve high efficiency in the gas core reactors. The model is also used to predict the convective and radiation heat fluxes for the gas core reactors. The maximum value of heat flux occurs at the exit of the reactor core. Radiation heat flux increases with higher wall temperature. This behavior is due to the fact that the radiative heat flux is strongly dependent on wall temperature. This study also found that at temperature close to 3500 K the radiative heat flux is comparable with the convective heat flux in a uranium fluoride failed gas core reactor.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFDR28010V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFDR28010V"><span>Reducing numerical costs for core wide nuclear reactor CFD simulations by the Coarse-Grid-CFD</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viellieber, Mathias; Class, Andreas G.</p> <p>2013-11-01</p> <p>Traditionally complete nuclear reactor core simulations are performed with subchannel analysis codes, that rely on experimental and empirical input. The Coarse-Grid-CFD (CGCFD) intends to replace the experimental or empirical input with CFD data. The reactor core consists of repetitive flow patterns, allowing the general approach of creating a parametrized model for one segment and composing many of those to obtain the entire reactor simulation. The method is based on a detailed and well-resolved CFD simulation of one representative segment. From this simulation we extract so-called parametrized volumetric forces which close, an otherwise strongly under resolved, coarsely-meshed model of a complete reactor setup. While the formulation so far accounts for forces created internally in the fluid others e.g. obstruction and flow deviation through spacers and wire wraps, still need to be accounted for if the geometric details are not represented in the coarse mesh. These are modelled with an Anisotropic Porosity Formulation (APF). This work focuses on the application of the CGCFD to a complete reactor core setup and the accomplishment of the parametrization of the volumetric forces.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvD..95j1302L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvD..95j1302L"><span>Tidal deformations of compact stars with crystalline quark matter</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lau, S. Y.; Leung, P. T.; Lin, L.-M.</p> <p>2017-05-01</p> <p>We study the tidal deformability of bare quark stars and hybrid compact stars composed of a quark-matter core in general relativity, assuming that the deconfined quark matter exists in a crystalline color superconducting phase. We find that taking the elastic property of crystalline quark matter into account in the calculation of the tidal deformability can break the universal I-Love relation discovered for fluid compact stars, which connects the moment of inertia and tidal deformability. Our result suggests that measurements of the moment of inertia and tidal deformability can in principle be used to test the existence of solid quark stars, despite our ignorance of the high-density equation of state. Assuming that the moment of inertia can be measured to 10% level, one can then distinguish a 1.4 (1 ) M⊙ solid quark star described by our quark-matter equation of state model with a gap parameter Δ =25 MeV from a fluid compact star if the tidal deformability can be measured to about 10% (45%) level. On the other hand, we find that the nuclear matter fluid envelope of a hybrid star can screen out the effect of the solid core significantly so that the resulting I-Love relation for hybrid stars still agrees with the universal relation for fluid stars to about 1% level.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss021e020304.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss021e020304.html"><span>Williams working on the JAXA MS (Marangoni Surface) Experiment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2009-11-05</p> <p>ISS021-E-020304 (5 Nov. 2009) --- NASA astronaut Jeffrey Williams, Expedition 21 flight engineer, works with Fluid Physics Experiment Facility/Marangoni Surface (FPEF MS) Core hardware in the Kibo laboratory of the International Space Station. Williams first inserted the Marangoni Inside (MI) cassette in the MI Core for a leak check, and then installed the MI Core into the FPEF MI Body. The Marangoni convection experiment in the FPEF examines fluid tension flow in micro-G.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930037356&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dearths%2Bouter%2Bcore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930037356&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dearths%2Bouter%2Bcore"><span>The steady part of the secular variation of the Earth's magnetic field</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bloxham, Jeremy</p> <p>1992-01-01</p> <p>The secular variation of the Earth's magnetic field results from the effects of magnetic induction in the fluid outer core and from the effects of magnetic diffusion in the core and the mantle. Adequate observations to map the magnetic field at the core-mantle boundary extend back over three centuries, providing a model of the secular variation at the core-mantle boundary. Here we consider how best to analyze this time-dependent part of the field. To calculate steady core flow over long time periods, we introduce an adaptation of our earlier method of calculating the flow in order to achieve greater numerical stability. We perform this procedure for the periods 1840-1990 and 1690-1840 and find that well over 90 percent of the variance of the time-dependent field can be explained by simple steady core flow. The core flows obtained for the two intervals are broadly similar to each other and to flows determined over much shorter recent intervals.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900010208','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900010208"><span>Dynamics of a class of vortex rings. Ph.D. Thesis - Stanford Univ.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shariff, Karim; Leonard, Anthony; Ferziger, Joel H.</p> <p>1989-01-01</p> <p>The contour dynamics method is extended to vortex rings with vorticity varying linearly from the symmetry axis. An elliptic core model is also developed to explain some of the basic physics. Passage and collisions of two identical rings are studied focusing on core deformation, sound generation and stirring of fluid elements. With respect to core deformation, not only the strain rate but how rapidly it varies is important and accounts for greater susceptibility to vortex tearing than in two dimensions. For slow strain, as a passage interaction is completed and the strain relaxes, the cores return to their original shape while permanent deformations remain for rapidly varying strain. For collisions, if the strain changes slowly the core shapes migrate through a known family of two-dimensional steady vortex pairs up to the limiting member of the family. Thereafter energy conservation does not allow the cores to maintain a constant shape. For rapidly varying strain, core deformation is severe and a head-tail structure in good agreement with experiments is formed. With respect to sound generation, good agreement with the measured acoustic signal for colliding rings is obtained and a feature previously thought to be due to viscous effects is shown to be an effect of inviscid core deformation alone. For passage interactions, a component of high frequency is present. Evidence for the importance of this noise source in jet noise spectra is provided. Finally, processes of fluid engulfment and rejection for an unsteady vortex ring are studied using the stable and unstable manifolds. The unstable manifold shows excellent agreement with flow visualization experiments for leapfrogging rings suggesting that it may be a good tool for numerical flow visualization in other time periodic flows.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HEDP...26....8Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HEDP...26....8Z"><span>Critical parameters, thermodynamic functions, and shock Hugoniot of aluminum fluid at high energy density</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zaghloul, Mofreh R.</p> <p>2018-03-01</p> <p>We present estimates of the critical properties, thermodynamic functions, and principal shock Hugoniot of hot dense aluminum fluid as predicted from a chemical model for the equation-of-state of hot dense, partially ionized and partially degenerate plasma. The essential features of strongly coupled plasma of metal vapors, such as multiple ionization, Coulomb interactions among charged particles, partial degeneracy, and intensive short range hard core repulsion are taken into consideration. Internal partition functions of neutral, excited, and multiply ionized species are carefully evaluated in a statistical-mechanically consistent way. Results predicted from the present model are presented, analyzed and compared with available experimental measurements and other theoretical predictions in the literature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1259534-altering-wettability-recover-more-oil-from-tight-formations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1259534-altering-wettability-recover-more-oil-from-tight-formations"><span>Altering wettability to recover more oil from tight formations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Brady, Patrick V.; Bryan, Charles R.; Thyne, Geoffrey; ...</p> <p>2016-06-03</p> <p>We describe here a method for chemically modifying fracturing fluids and overflushes to chemically increase oil recovery from tight formations. Oil wetting of tight formations is usually controlled by adhesion to illite, kerogen, or both; adhesion to carbonate minerals may also play a role. Oil-illite adhesion is sensitive to salinity, dissolved divalent cation content, and pH. We measure oil-rock adhesion with middle Bakken formation oil and core to verify a surface complexation model of reservoir wettability. The agreement between the model and experiments suggests that wettability trends in tight formations can be quantitatively predicted and that fracturing fluid and overflushmore » compositions can be individually tailored to increase oil recovery.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1259534','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1259534"><span>Altering wettability to recover more oil from tight formations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Brady, Patrick V.; Bryan, Charles R.; Thyne, Geoffrey</p> <p></p> <p>We describe here a method for chemically modifying fracturing fluids and overflushes to chemically increase oil recovery from tight formations. Oil wetting of tight formations is usually controlled by adhesion to illite, kerogen, or both; adhesion to carbonate minerals may also play a role. Oil-illite adhesion is sensitive to salinity, dissolved divalent cation content, and pH. We measure oil-rock adhesion with middle Bakken formation oil and core to verify a surface complexation model of reservoir wettability. The agreement between the model and experiments suggests that wettability trends in tight formations can be quantitatively predicted and that fracturing fluid and overflushmore » compositions can be individually tailored to increase oil recovery.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvC..96f5803F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvC..96f5803F"><span>Nonradial oscillation modes of compact stars with a crust</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flores, Cesar Vásquez; Hall, Zack B.; Jaikumar, Prashanth</p> <p>2017-12-01</p> <p>Oscillation modes of isolated compact stars can, in principle, be a fingerprint of the equation of state (EoS) of dense matter. We study the non-radial high-frequency l =2 spheroidal modes of neutron stars and strange quark stars, adopting a two-component model (core and crust) for these two types of stars. Using perturbed fluid equations in the relativistic Cowling approximation, we explore the effect of a strangelet or hadronic crust on the oscillation modes of strange stars. The results differ from the case of neutron stars with a crust. In comparison to fluid-only configurations, we find that a solid crust on top of a neutron star increases the p -mode frequency slightly with little effect on the f -mode frequency, whereas for strange stars, a strangelet crust on top of a quark core significantly increases the f -mode frequency with little effect on the p -mode frequency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/862457','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/862457"><span>Emergency heat removal system for a nuclear reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dunckel, Thomas L.</p> <p>1976-01-01</p> <p>A heat removal system for nuclear reactors serving as a supplement to an Emergency Core Cooling System (ECCS) during a Loss of Coolant Accident (LOCA) comprises a plurality of heat pipes having one end in heat transfer relationship with either the reactor pressure vessel, the core support grid structure or other in-core components and the opposite end located in heat transfer relationship with a heat exchanger having heat transfer fluid therein. The heat exchanger is located external to the pressure vessel whereby excessive core heat is transferred from the above reactor components and dissipated within the heat exchanger fluid.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810011154','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810011154"><span>Magnetic space-based field measurements</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Langel, R. A.</p> <p>1981-01-01</p> <p>Because the near Earth magnetic field is a complex combination of fields from outside the Earth of fields from its core and of fields from its crust, measurements from space prove to be the only practical way to obtain timely, global surveys. Due to difficulty in making accurate vector measurements, early satellites such as Sputnik and Vanguard measured only the magnitude survey. The attitude accuracy was 20 arc sec. Both the Earth's core fields and the fields arising from its crust were mapped from satellite data. The standard model of the core consists of a scalar potential represented by a spherical harmonics series. Models of the crustal field are relatively new. Mathematical representation is achieved in localized areas by arrays of dipoles appropriately located in the Earth's crust. Measurements of the Earth's field are used in navigation, to map charged particles in the magnetosphere, to study fluid properties in the Earth's core, to infer conductivity of the upper mantels, and to delineate regional scale geological features.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120014581','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120014581"><span>Production Level CFD Code Acceleration for Hybrid Many-Core Architectures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Duffy, Austen C.; Hammond, Dana P.; Nielsen, Eric J.</p> <p>2012-01-01</p> <p>In this work, a novel graphics processing unit (GPU) distributed sharing model for hybrid many-core architectures is introduced and employed in the acceleration of a production-level computational fluid dynamics (CFD) code. The latest generation graphics hardware allows multiple processor cores to simultaneously share a single GPU through concurrent kernel execution. This feature has allowed the NASA FUN3D code to be accelerated in parallel with up to four processor cores sharing a single GPU. For codes to scale and fully use resources on these and the next generation machines, codes will need to employ some type of GPU sharing model, as presented in this work. Findings include the effects of GPU sharing on overall performance. A discussion of the inherent challenges that parallel unstructured CFD codes face in accelerator-based computing environments is included, with considerations for future generation architectures. This work was completed by the author in August 2010, and reflects the analysis and results of the time.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22026864','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22026864"><span>A key to improved ion core confinement in the JET tokamak: ion stiffness mitigation due to combined plasma rotation and low magnetic shear.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mantica, P; Angioni, C; Challis, C; Colyer, G; Frassinetti, L; Hawkes, N; Johnson, T; Tsalas, M; deVries, P C; Weiland, J; Baiocchi, B; Beurskens, M N A; Figueiredo, A C A; Giroud, C; Hobirk, J; Joffrin, E; Lerche, E; Naulin, V; Peeters, A G; Salmi, A; Sozzi, C; Strintzi, D; Staebler, G; Tala, T; Van Eester, D; Versloot, T</p> <p>2011-09-23</p> <p>New transport experiments on JET indicate that ion stiffness mitigation in the core of a rotating plasma, as described by Mantica et al. [Phys. Rev. Lett. 102, 175002 (2009)] results from the combined effect of high rotational shear and low magnetic shear. The observations have important implications for the understanding of improved ion core confinement in advanced tokamak scenarios. Simulations using quasilinear fluid and gyrofluid models show features of stiffness mitigation, while nonlinear gyrokinetic simulations do not. The JET experiments indicate that advanced tokamak scenarios in future devices will require sufficient rotational shear and the capability of q profile manipulation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMDI31A1788H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMDI31A1788H"><span>Two-Phase Dynamics Simulations of the Growth and Instability of Earth's Inner Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernlund, J. W.; Jellinek, M.; Labrosse, S.</p> <p>2008-12-01</p> <p>When the center of Earth's core began to freeze from a homogeneous liquid 1-2 billion years ago, its constitution was very likely that of a mushy region. As this incipient inner core grew by further crystallization of the outer core, an increase in gravity force allowed for the solid grains to compress against one another, undergo viscous compaction, and begin to expel remnant fluid out of the inner core by percolation. Meanwhile, inside the inner core the residual fluid and solid remained in equilibrium, and any perturbations that resulted in upwelling of the deformable mush would also be accompanied by decompression melting. Upwelling and melting regions might then increase in liquid fraction, become less dense, and hence buoyant in a way that would propel them upward at a faster rate, setting up a runaway instability and partial Rayleigh-Taylor-like overturn of Earth's inner core. Structures inherited from this event possibly include the distinct innermost inner core posited by seismologists to exist at Earth's centermost 300-600 km. We use a new two-phase dynamics code to model this scenario in axi-symmetric geometry in order to understand whether and when such an instability occurred, what size the core will have been at the onset of instability, and the degree and style of deformation that would have accompanied this episode. We have found that the growth of instability competes with the rate of background melt percolation, such that the instability would only have occurred after the inner core reaches a critical size and expelled a certain amount of liquid from its interior. A linear stability analysis confirms that there is a critical Rayleigh number for the onset of instability at a given radius. The combined constraints show that the inner core is guaranteed to have undergone this kind of instability, at a time and strength governed solely by physical properties such as grain size, density differences between liquid and solid, and viscosities of the phases.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22679712-steamworlds-atmospheric-structure-critical-mass-planets-accreting-icy-pebbles','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22679712-steamworlds-atmospheric-structure-critical-mass-planets-accreting-icy-pebbles"><span>Steamworlds: Atmospheric Structure and Critical Mass of Planets Accreting Icy Pebbles</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chambers, John, E-mail: jchambers@carnegiescience.edu</p> <p></p> <p>In the core accretion model, gas-giant planets first form a solid core, which then accretes gas from a protoplanetary disk when the core exceeds a critical mass. Here, we model the atmosphere of a core that grows by accreting ice-rich pebbles. The ice fraction of pebbles evaporates in warm regions of the atmosphere, saturating it with water vapor. Excess water precipitates to lower altitudes. Beneath an outer radiative region, the atmosphere is convective, following a moist adiabat in saturated regions due to water condensation and precipitation. Atmospheric mass, density, and temperature increase with core mass. For nominal model parameters, planetsmore » with core masses (ice + rock) between 0.08 and 0.16 Earth masses have surface temperatures between 273 and 647 K and form an ocean. In more massive planets, water exists as a supercritical convecting fluid mixed with gas from the disk. Typically, the core mass reaches a maximum (the critical mass) as a function of the total mass when the core is 2–5 Earth masses. The critical mass depends in a complicated way on pebble size, mass flux, and dust opacity due to the occasional appearance of multiple core-mass maxima. The core mass for an atmosphere of 50% hydrogen and helium may be a more robust indicator of the onset of gas accretion. This mass is typically 1–3 Earth masses for pebbles that are 50% ice by mass, increasing with opacity and pebble flux and decreasing with pebble ice/rock ratio.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1901k0005I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1901k0005I"><span>Identification of sandstone core damage using scanning electron microscopy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ismail, Abdul Razak; Jaafar, Mohd Zaidi; Sulaiman, Wan Rosli Wan; Ismail, Issham; Shiunn, Ng Yinn</p> <p>2017-12-01</p> <p>Particles and fluids invasion into the pore spaces causes serious damage to the formation, resulting reduction in petroleum production. In order to prevent permeability damage for a well effectively, the damage mechanisms should be identified. In this study, water-based drilling fluid was compared to oil-based drilling fluids based on microscopic observation. The cores were damaged by several drilling fluid systems. Scanning electron microscope (SEM) was used to observe the damage mechanism caused by the drilling fluids. Results showed that the ester based drilling fluid system caused the most serious damage followed by synthetic oil based system and KCI-polymer system. Fine solids and filtrate migration and emulsion blockage are believed to be the major mechanisms controlling the changes in flow properties for the sandstone samples.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22572113-condensation-galactic-cold-dark-matter','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22572113-condensation-galactic-cold-dark-matter"><span>Condensation of galactic cold dark matter</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Visinelli, Luca</p> <p>2016-07-07</p> <p>We consider the steady-state regime describing the density profile of a dark matter halo, if dark matter is treated as a Bose-Einstein condensate. We first solve the fluid equation for “canonical” cold dark matter, obtaining a class of density profiles which includes the Navarro-Frenk-White profile, and which diverge at the halo core. We then solve numerically the equation obtained when an additional “quantum pressure” term is included in the computation of the density profile. The solution to this latter case is finite at the halo core, possibly avoiding the “cuspy halo problem” present in some cold dark matter theories. Withinmore » the model proposed, we predict the mass of the cold dark matter particle to be of the order of M{sub χ}c{sup 2}≈10{sup −24} eV, which is of the same order of magnitude as that predicted in ultra-light scalar cold dark matter models. Finally, we derive the differential equation describing perturbations in the density and the pressure of the dark matter fluid.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930017232','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930017232"><span>Steady induction effects in geomagnetism. Part 1B: Geomagnetic estimation of steady surficial core motions: A non-linear inverse problem</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Voorhies, Coerte V.</p> <p>1993-01-01</p> <p>The problem of estimating a steady fluid velocity field near the top of Earth's core which induces the secular variation (SV) indicated by models of the observed geomagnetic field is examined in the source-free mantle/frozen-flux core (SFI/VFFC) approximation. This inverse problem is non-linear because solutions of the forward problem are deterministically chaotic. The SFM/FFC approximation is inexact, and neither the models nor the observations they represent are either complete or perfect. A method is developed for solving the non-linear inverse motional induction problem posed by the hypothesis of (piecewise, statistically) steady core surface flow and the supposition of a complete initial geomagnetic condition. The method features iterative solution of the weighted, linearized least-squares problem and admits optional biases favoring surficially geostrophic flow and/or spatially simple flow. Two types of weights are advanced radial field weights for fitting the evolution of the broad-scale portion of the radial field component near Earth's surface implied by the models, and generalized weights for fitting the evolution of the broad-scale portion of the scalar potential specified by the models.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.7946P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.7946P"><span>Does serpentinite carbonation occur during recharge or discharge of hydrothermal fluids? A case of study from the Newfoundland margin</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Picazo, Suzanne; Malvoisin, Benjamin; Baumgartner, Lukas P.; Bouvier, Anne-Sophie</p> <p>2017-04-01</p> <p>Hydrothermal fluid circulation in extensional systems occurrs along the spreading axis of passive, hyper-extended margins and mid-ocean ridges. The most studied feature resulting from hydrothermal circulation is the sub-seafloor chimneys because of their accessibility. Here we focus on the less studied carbonation process of the associated serpentinites. Carbonation of partially to totally serpentinized peridotite i.e. peridotite/serpentinite replacement by carbonate is usually described as a process of veining or matrix formation but not direct replacement of serpentinite. Carbonates that crystallize in veins or as a matrix in a sedimentary setting is known in near-surface environments like Oman (Kelemen et al, 2011), however the processes and timing of carbonation are still not well understood. This study is examins in detail the onset of carbonation in the footwall of the detachment faults responsible for mantle exhumation in hyper-extended rifted margins. It is based on drilled samples from ODP Leg 210 Site 1277 in the Newfoundland margin. We observed calcite grains in the mesh core replacing serpentine and we measured δ18O from core to rim of the calcite grain using the Secondary Ion Mass Spectrometer (SIMS, SwissSIMS facility, University of Lausanne). Ultimately δ18O measurements lead us to infer the temperature of calcite growth. We suplement the study with equilibrium thermodynamic modeling in an open system where fluid can be transported either upwards or downwards. The model allows us determining the influence of fluid flow direction, temperature, pressure and fluid/rock ratio on the stability of carbonates and serpentine, and thus to discuss if carbonation occurs during recharge or discharge of the fluids. Kelemen, P. B., Matter, J., Streit, E. E., Rudge, J. F., Curry, W. B., & Blusztajn, J. (2011). Rates and mechanisms of mineral carbonation in peridotite: natural processes and recipes for enhanced, in situ CO2 capture and storage. Annual Review of Earth and Planetary Sciences, 39, 545-576.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212878D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212878D"><span>The Fluid Flow Evolution During the Seismic Cycle Within Overpressured Fault Zones</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Paola, Nicola; Vanhunen, Jeroen; Collettini, Cristiano; Faulkner, Dan</p> <p>2010-05-01</p> <p>The integration of seismic reflection profiles with well-located earthquakes shows that the mainshocks of the 1997 Umbria-Marche seismic sequence (Mw < 6) nucleated at about 6 km depth, within the Triassic Evaporites, a 2 km thick sequence made of interbedded anhydrites and dolostones. Two boreholes, drilled northwest of the epicentral area, encountered CO2 fluid overpressures at about 0.8 of the lithostatic load, at about 4 km depth. It has been proposed that the time-space evolution of the 1997 aftershock sequence, was driven by the coseismic release of trapped high-pressure fluids (lv = 0.8), within the Triassic Evaporites. In order to understand whether CO2 fluid overpressure can be maintained up to the coseismic period, and trigger earthquake nucleation, we modelled fluid flow through a mature fault zone within the Triassic Evaporites. We assume that fluid flow within the fault zone occurs in accord with the Darcy's Law. Under this condition, a near lithostatic pore pressure gradient can develop, within the fault zone, when the upward transport of fluid along the fault zone exceeds the fluid loss in a horizontal direction. Our model's parameters are: a) Fault zone structure: model inputs have been obtained from large fault zone analogues derived from field observation. The architecture of large fault zones within the TE is given by a distinct fault core, up to few meters thick, of very fine-grained fault rocks (cataclasites and fault gouge), where most of the shear strain has been accommodated, surrounded by a geometrically complex and heterogeneous damage zone (up to few tens of meters wide). The damage zone is characterized by adjacent zones of heavily fractured rocks (dolostones) and foliated rocks displaying little fracturing (anhydrites). b) Fault zone permeability: field data suggests that the permeability of the fault core is relatively low due to the presence of fine grained fault rocks (k < 10E-18 m2). The permeability of the dolostones, within the damage zone, is likely to be high and controlled by mesoscale fracture patterns (k > 10E-17 m2). For the anhydrites, the permeability and porosity development was continuously measured prior and throughout triaxial loading tests, performed on borehole samples. The permeability of the anhydrites within the damage zone, due to the absence of mesoscale fracture patterns within Ca-sulphates layers, has been assumed to be as low as the values measured during our lab experiments (k = 10E-17 - 10E-20 m2). Our model results show that, during the seismic cycle, the lateral fluid flux, across the fault zone, is always lower than the vertical parallel fluid flux. Under these conditions fluid overpressure within the fault zone can be sustained up to the coseismic period when earthquake nucleation occurs. Our modelling shows that during extensional loading, overpressured fault zones within the Triassic Evaporites may develop and act as asperities, i.e. they are mechanically weaker than faults within the overlain carbonates at hydrostatic (lv = 0.4) pore fluid pressure conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960001697','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960001697"><span>HPTAM, a two-dimensional Heat Pipe Transient Analysis Model, including the startup from a frozen state</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tournier, Jean-Michel; El-Genk, Mohamed S.</p> <p>1995-01-01</p> <p>A two-dimensional Heat Pipe Transient Analysis Model, 'HPTAM,' was developed to simulate the transient operation of fully-thawed heat pipes and the startup of heat pipes from a frozen state. The model incorporates: (a) sublimation and resolidification of working fluid; (b) melting and freezing of the working fluid in the porous wick; (c) evaporation of thawed working fluid and condensation as a thin liquid film on a frozen substrate; (d) free-molecule, transition, and continuum vapor flow regimes, using the Dusty Gas Model; (e) liquid flow and heat transfer in the porous wick; and (f) thermal and hydrodynamic couplings of phases at their respective interfaces. HPTAM predicts the radius of curvature of the liquid meniscus at the liquid-vapor interface and the radial location of the working fluid level (liquid or solid) in the wick. It also includes the transverse momentum jump condition (capillary relationship of Pascal) at the liquid-vapor interface and geometrically relates the radius of curvature of the liquid meniscus to the volume fraction of vapor in the wick. The present model predicts the capillary limit and partial liquid recess (dryout) in the evaporator wick, and incorporates a liquid pooling submodel, which simulates accumulation of the excess liquid in the vapor core at the condenser end.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP21H..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP21H..05L"><span>Attenuation of Chemical Reactivity of Shale Matrixes following Scale Precipitation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Q.; Jew, A. D.; Kohli, A. H.; Alalli, G.; Kiss, A. M.; Kovscek, A. R.; Zoback, M. D.; Brown, G. E.; Maher, K.; Bargar, J.</p> <p>2017-12-01</p> <p>Introduction of fracture fluids into shales initiates a myriad of fluid-rock reactions that can strongly influence migration of fluid and hydrocarbon through shale/fracture interfaces. Due to the extremely low permeability of shale matrixes, studies on chemical reactivity of shales have mostly focused on shale surfaces. Shale-fluid interactions inside within shale matrixes have not been examined, yet the matrix is the primary conduit through which hydrocarbons and potential contaminants are transmitted. To characterize changes in matrix mineralogy, porosity, diffusivity, and permeability during hydraulic stimulation, we reacted Marcellus (high clay and low carbonate) and Eagle Ford (low clay and high carbonate) shale cores with fracture fluids for 3 weeks at elevated pressure and temperature (80 oC, and 77 bars). In the carbonate-poor Marcellus system, fluid pH increased from 2 to 4, and secondary Fe(OH)3 precipitates were observed in the fluid. Sulfur X-ray fluorescence maps show that fluids had saturated and reacted with the entire 1-cm-diameter core. In the carbonate-rich Eagle Ford system, pH increased from 2 to 6 due to calcite dissolution. When additional Ba2+ and SO42- were present (log10(Q/K)=1.3), extensive barite precipitation was observed in the matrix of the Eagle Ford core (and on the surface). Barite precipitation was also observed on the surface of the Marcellus core, although to a lesser extent. In the Marcellus system, the presence of barite scale attenuated diffusivity in the matrix, as demonstrated by sharply reduced Fe leaching and much less sulfide oxidation. Systematic studies in homogeneous solution show that barite scale precipitation rates are highly sensitive to pH, salinity, and the presence of organic compounds. These findings imply that chemical reactions are not confined to shale/fluid interfaces but can penetrate into shale matrices, and that barite scale formation can clog diffusion pathways for both fluid and hydrocarbon.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CeMDA.126...61P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CeMDA.126...61P"><span>Determining parameters of Moon's orbital and rotational motion from LLR observations using GRAIL and IERS-recommended models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlov, Dmitry A.; Williams, James G.; Suvorkin, Vladimir V.</p> <p>2016-11-01</p> <p>The aim of this work is to combine the model of orbital and rotational motion of the Moon developed for DE430 with up-to-date astronomical, geodynamical, and geo- and selenophysical models. The parameters of the orbit and physical libration are determined in this work from lunar laser ranging (LLR) observations made at different observatories in 1970-2013. Parameters of other models are taken from solutions that were obtained independently from LLR. A new implementation of the DE430 lunar model, including the liquid core equations, was done within the EPM ephemeris. The postfit residuals of LLR observations make evident that the terrestrial models and solutions recommended by the IERS Conventions are compatible with the lunar theory. That includes: EGM2008 gravitational potential with conventional corrections and variations from solid and ocean tides; displacement of stations due to solid and ocean loading tides; and precession-nutation model. Usage of these models in the solution for LLR observations has allowed us to reduce the number of parameters to be fit. The fixed model of tidal variations of the geopotential has resulted in a lesser value of Moon's extra eccentricity rate, as compared to the original DE430 model with two fit parameters. A mixed model of lunar gravitational potential was used, with some coefficients determined from LLR observations, and other taken from the GL660b solution obtained from the GRAIL spacecraft mission. Solutions obtain accurate positions for the ranging stations and the five retroreflectors. Station motion is derived for sites with long data spans. Dissipation is detected at the lunar fluid core-solid mantle boundary demonstrating that a fluid core is present. Tidal dissipation is strong at both Earth and Moon. Consequently, the lunar semimajor axis is expanding by 38.20 mm/yr, the tidal acceleration in mean longitude is -25.90 {{}^' ' }}/cy^2, and the eccentricity is increasing by 1.48× 10^{-11} each year.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.656a2084H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.656a2084H"><span>A comprehensive Two-Fluid Model for Cavitation and Primary Atomization Modelling of liquid jets - Application to a large marine Diesel injector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habchi, Chawki; Bohbot, Julien; Schmid, Andreas; Herrmann, Kai</p> <p>2015-12-01</p> <p>In this paper, a comprehensive two-fluid model is suggested in order to compute the in-nozzle cavitating flow and the primary atomization of liquid jets, simultaneously. This model has been applied to the computation of a typical large marine Diesel injector. The numerical results have shown a strong correlation between the in-nozzle cavitating flow and the ensuing spray orientation and atomization. Indeed, the results have confirmed the existence of an off-axis liquid core. This asymmetry is likely to be at the origin of the spray deviation observed experimentally. In addition, the primary atomization begins very close to the orifice exit as in the experiments, and the smallest droplets are generated due to cavitation pocket shape oscillations located at the same side, inside the orifice.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1173099','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1173099"><span>MATCHED-INDEX-OF-REFRACTION FLOW FACILITY FOR FUNDAMENTAL AND APPLIED RESEARCH</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Piyush Sabharwall; Carl Stoots; Donald M. McEligot</p> <p>2014-11-01</p> <p>Significant challenges face reactor designers with regard to thermal hydraulic design and associated modeling for advanced reactor concepts. Computational thermal hydraulic codes solve only a piece of the core. There is a need for a whole core dynamics system code with local resolution to investigate and understand flow behavior with all the relevant physics and thermo-mechanics. The matched index of refraction (MIR) flow facility at Idaho National Laboratory (INL) has a unique capability to contribute to the development of validated computational fluid dynamics (CFD) codes through the use of state-of-the-art optical measurement techniques, such as Laser Doppler Velocimetry (LDV) andmore » Particle Image Velocimetry (PIV). PIV is a non-intrusive velocity measurement technique that tracks flow by imaging the movement of small tracer particles within a fluid. At the heart of a PIV calculation is the cross correlation algorithm, which is used to estimate the displacement of particles in some small part of the image over the time span between two images. Generally, the displacement is indicated by the location of the largest peak. To quantify these measurements accurately, sophisticated processing algorithms correlate the locations of particles within the image to estimate the velocity (Ref. 1). Prior to use with reactor deign, the CFD codes have to be experimentally validated, which requires rigorous experimental measurements to produce high quality, multi-dimensional flow field data with error quantification methodologies. Computational thermal hydraulic codes solve only a piece of the core. There is a need for a whole core dynamics system code with local resolution to investigate and understand flow behavior with all the relevant physics and thermo-mechanics. Computational techniques with supporting test data may be needed to address the heat transfer from the fuel to the coolant during the transition from turbulent to laminar flow, including the possibility of an early laminarization of the flow (Refs. 2 and 3) (laminarization is caused when the coolant velocity is theoretically in the turbulent regime, but the heat transfer properties are indicative of the coolant velocity being in the laminar regime). Such studies are complicated enough that computational fluid dynamics (CFD) models may not converge to the same conclusion. Thus, experimentally scaled thermal hydraulic data with uncertainties should be developed to support modeling and simulation for verification and validation activities. The fluid/solid index of refraction matching technique allows optical access in and around geometries that would otherwise be impossible while the large test section of the INL system provides better spatial and temporal resolution than comparable facilities. Benchmark data for assessing computational fluid dynamics can be acquired for external flows, internal flows, and coupled internal/external flows for better understanding of physical phenomena of interest. The core objective of this study is to describe MIR and its capabilities, and mention current development areas for uncertainty quantification, mainly the uncertainty surface method and cross-correlation method. Using these methods, it is anticipated to establish a suitable approach to quantify PIV uncertainty for experiments performed in the MIR.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.3001A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.3001A"><span>Geomagnetic inverse problem and data assimilation: a progress report</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aubert, Julien; Fournier, Alexandre</p> <p>2013-04-01</p> <p>In this presentation I will present two studies recently undertaken by our group in an effort to bring the benefits of data assimilation to the study of Earth's magnetic field and the dynamics of its liquid iron core, where the geodynamo operates. In a first part I will focus on the geomagnetic inverse problem, which attempts to recover the fluid flow in the core from the temporal variation of the magnetic field (known as the secular variation). Geomagnetic data can be downward continued from the surface of the Earth down to the core-mantle boundary, but not further below, since the core is an electrical conductor. Historically, solutions to the geomagnetic inverse problem in such a sparsely observed system were thus found only for flow immediately below the core mantle boundary. We have recently shown that combining a numerical model of the geodynamo together with magnetic observations, through the use of Kalman filtering, now allows to present solutions for flow throughout the core. In a second part, I will present synthetic tests of sequential geomagnetic data assimilation aiming at evaluating the range at which the future of the geodynamo can be predicted, and our corresponding prospects to refine the current geomagnetic predictions. Fournier, Aubert, Thébault: Inference on core surface flow from observations and 3-D dynamo modelling, Geophys. J. Int. 186, 118-136, 2011, doi: 10.1111/j.1365-246X.2011.05037.x Aubert, Fournier: Inferring internal properties of Earth's core dynamics and their evolution from surface observations and a numerical geodynamo model, Nonlinear Proc. Geoph. 18, 657-674, 2011, doi:10.5194/npg-18-657-2011 Aubert: Flow throughout the Earth's core inverted from geomagnetic observations and numerical dynamo models, Geophys. J. Int., 2012, doi: 10.1093/gji/ggs051</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990115475&hterms=geodesy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeodesy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990115475&hterms=geodesy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeodesy"><span>Monitoring Global Geophysical Fluids by Space Geodesy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chao, Benjamin F.; Dehant, V.; Gross, R. S.; Ray, R. D.; Salstein, D. A.; Watkins, M.</p> <p>1999-01-01</p> <p>Since its establishment on 1/1/1998 by the International Earth Rotation Service, the Coordinating Center for Monitoring Global Geophysical Fluids (MGGF) and its seven Special Bureaus have engaged in an effort to support and facilitate the understanding of the geophysical fluids in global geodynamics research. Mass transports in the atmosphere-hydrosphere-solid Earth-core system (the "global geophysical fluids") will cause the following geodynamic effects on a broad time scale: (1) variations in the solid Earth's rotation (in length-of-day and polar motion/nutation) via the conservation of angular momentum and effected by torques at the fluid-solid Earth interface; (2) changes in the global gravitational field according to Newton's gravitational law; and (3) motion in the center of mass of the solid Earth relative to that of the whole Earth ("geocenter") via the conservation of linear momentum. These minute signals have become observable by space geodetic techniques, primarily VLBI, SLR, GPS, and DORIS, with ever increasing precision/accuracy and temporal/spatial resolution. Each of the seven Special Bureaus within MGGF is responsible for calculations related to a specific Earth component or aspect -- Atmosphere, Ocean, Hydrology, Ocean Tides, Mantle, Core, and Gravity/Geocenter. Angular momenta and torques, gravitational coefficients, and geocenter shift will be computed for geophysical fluids based on global observational data, and from state-of-the-art models, some of which assimilate such data. The computed quantities, algorithm and data formats are standardized. The results are archived and made available to the scientific research community. This paper reports the status of the MGGF activities and current results.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25866139','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25866139"><span>Warming of intravenous and irrigation fluids for preventing inadvertent perioperative hypothermia.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campbell, Gillian; Alderson, Phil; Smith, Andrew F; Warttig, Sheryl</p> <p>2015-04-13</p> <p>Inadvertent perioperative hypothermia (a drop in core temperature to below 36°C) occurs because of interference with normal temperature regulation by anaesthetic drugs, exposure of skin for prolonged periods and receipt of large volumes of intravenous and irrigation fluids. If the temperature of these fluids is below core body temperature, they can cause significant heat loss. Warming intravenous and irrigation fluids to core body temperature or above might prevent some of this heat loss and subsequent hypothermia. To estimate the effectiveness of preoperative or intraoperative warming, or both, of intravenous and irrigation fluids in preventing perioperative hypothermia and its complications during surgery in adults. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 2), MEDLINE Ovid SP (1956 to 4 February 2014), EMBASE Ovid SP (1982 to 4 February 2014), the Institute for Scientific Information (ISI) Web of Science (1950 to 4 February 2014), Cumulative Index to Nursing and Allied Health Literature (CINAHL) EBSCOhost (1980 to 4 February 2014) and reference lists of identified articles. We also searched the Current Controlled Trials website and ClinicalTrials.gov. We included randomized controlled trials or quasi-randomized controlled trials comparing fluid warming methods versus standard care or versus other warming methods used to maintain normothermia. Two review authors independently extracted data from eligible trials and settled disputes with a third review author. We contacted study authors to ask for additional details when needed. We collected data on adverse events only if they were reported in the trials. We included in this review 24 studies with a total of 1250 participants. The trials included various numbers and types of participants. Investigators used a range of methods to warm fluids to temperatures between 37°C and 41°C. We found that evidence was of moderate quality because descriptions of trial design were often unclear, resulting in high or unclear risk of bias due to inappropriate or unclear randomization and blinding procedures. These factors may have influenced results in some way. Our protocol specified the risk of hypothermia as the primary outcome; as no trials reported this, we decided to include data related to mean core temperature. The only secondary outcome reported in the trials that provided useable data was shivering. Evidence was unclear regarding the effects of fluid warming on bleeding. No data were reported on our other specified outcomes of cardiovascular complications, infection, pressure ulcers, bleeding, mortality, length of stay, unplanned intensive care admission and adverse events.Researchers found that warmed intravenous fluids kept the core temperature of study participants about half a degree warmer than that of participants given room temperature intravenous fluids at 30, 60, 90 and 120 minutes, and at the end of surgery. Warmed intravenous fluids also further reduced the risk of shivering compared with room temperature intravenous fluidsInvestigators reported no statistically significant differences in core body temperature or shivering between individuals given warmed and room temperature irrigation fluids. Warm intravenous fluids appear to keep patients warmer during surgery than room temperature fluids. It is unclear whether the actual differences in temperature are clinically meaningful, or if other benefits or harms are associated with the use of warmed fluids. It is also unclear if using fluid warming in addition to other warming methods confers any benefit, as a ceiling effect is likely when multiple methods of warming are used.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70015445','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70015445"><span>The campi flegrei (Italy) geothermal system: A fluid inclusion study of the mofete and San Vito fields</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>de, Vivo B.; Belkin, H.E.; Barbieri, M.; Chelini, W.; Lattanzi, P.; Lima, A.; Tolomeo, L.</p> <p>1989-01-01</p> <p>A fluid inclusion study of core from the Mofete 1, Mofete 2, Mofete 5, San Vito 1, and San Vito 3 geothermal wells (Campi Flegrei, Campania, Italy) indicates that the hydrothermal minerals were precipitated from aqueous fluids (??CO2) that were moderately saline (3-4 wt.% NaCl equiv.) to hypersaline (> 26 wt.% NaCl equiv.) and at least in part, boiling. Three types of primary fluid inclusions were found in authigenic K-feldspar, quartz, calcite, and epidote: (A) two-phase [liquid (L) + vapor (V)], liquid-rich inclusions with a range of salinity; (B) two-phase (L + V), vaporrich inclusions with low salinity; and (C) three-phase [L + V + crystals (NaCL)], liquid-rich inclusions with hypersalinity. Results of microthermometric and crushing studies are reported for twenty drill core samples taken from the lower portions of the five vertical wells. Data presented for selected core samples reveal a general decrease in porosity and increase in bulk density with increasing depth and temperature. Hydrothermal minerals commonly fill fractures and pore-spaces and define a zonation pattern, similar in all five wells studied, in response to increasing depth (pressure) and temperature. A greenschist facies assemblage, defined by albite + actinolite, gives way to an amphibolite facies, defined by plagioclase (andesine) + hornblende, in the San Vito 1 well at about 380??C. The fluid inclusion salinity values mimic the saline and hypersaline fluids found by drilling. Fluid inclusion V/L homogenization temperatures increase with depth and generally correspond to the extrapolated down-hole temperatures. However, fluid inclusion data for Mofete 5 and mineral assemblage data for San Vito 3, indicate fossil, higher-temperature regimes. A limited 87Sr/86Sr study of leachate (carbonate) and the leached cores shows that for most samples (except San Vito 3) the carbonate deposition has been from slightly 87Sr-enriched fluids and that Sr isotopic exchange has been incomplete. However, San Vito 3 cores show an approach to fluid/rock Sr equilibrium with a fluid similar to modern ocean water in 87Sr/86Sr ratio. The Campi Flegrei volcanic system has evolved undersaturated products, mostly trachyte, and defines a large (??? 12 km) caldera. The hydrothermal system developed in this location can be used as an analog for fossil systems in similar trachytic environments. The potential for ore mineralization is expressed by the recognition, from fluid inclusion and drilling data, of ore-forming environments such as boiling and brine stratification. ?? 1989.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H33I..02P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H33I..02P"><span>Advanced core-analyses for subsurface characterization</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pini, R.</p> <p>2017-12-01</p> <p>The heterogeneity of geological formations varies over a wide range of length scales and represents a major challenge for predicting the movement of fluids in the subsurface. Although they are inherently limited in the accessible length-scale, laboratory measurements on reservoir core samples still represent the only way to make direct observations on key transport properties. Yet, properties derived on these samples are of limited use and should be regarded as sample-specific (or `pseudos'), if the presence of sub-core scale heterogeneities is not accounted for in data processing and interpretation. The advent of imaging technology has significantly reshaped the landscape of so-called Special Core Analysis (SCAL) by providing unprecedented insight on rock structure and processes down to the scale of a single pore throat (i.e. the scale at which all reservoir processes operate). Accordingly, improved laboratory workflows are needed that make use of such wealth of information by e.g., referring to the internal structure of the sample and in-situ observations, to obtain accurate parameterisation of both rock- and flow-properties that can be used to populate numerical models. We report here on the development of such workflow for the study of solute mixing and dispersion during single- and multi-phase flows in heterogeneous porous systems through a unique combination of two complementary imaging techniques, namely X-ray Computed Tomography (CT) and Positron Emission Tomography (PET). The experimental protocol is applied to both synthetic and natural porous media, and it integrates (i) macroscopic observations (tracer effluent curves), (ii) sub-core scale parameterisation of rock heterogeneities (e.g., porosity, permeability and capillary pressure), and direct 3D observation of (iii) fluid saturation distribution and (iv) the dynamic spreading of the solute plumes. Suitable mathematical models are applied to reproduce experimental observations, including both 1D and 3D numerical schemes populated with the parameterisation above. While it validates the core-flooding experiments themselves, the calibrated mathematical model represents a key element for extending them to conditions prevalent in the subsurface, which would be otherwise not attainable in the laboratory.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H41C1305T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H41C1305T"><span>Hydrologic Responses to CO2 Injection in Basalts Based on Flow-through Experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, D.; Hingerl, F.; Garing, C.; Bird, D. K.; Benson, S. M.; Maher, K.</p> <p>2015-12-01</p> <p>Experimental studies of basalt-CO2 interactions have increased our ability to predict geochemical responses within a mafic reservoir during geologic CO2 sequestration. However, the lack of flow-through experiments prevents the use of coupled hydrologic-geochemical models to predict evolution of permeability and porosity, critical parameters for assessing storage feasibility. We present here results of three flow-through experiments on an intact basalt core during which we employed X-ray Computed Tomography (CT) to quantify porosity evolution and fluid flow. Using a single core of glassy basaltic tuff from the Snake River Plain (Menan Buttes complex), we performed tracer tests using a solution of NaI (~100,000 ppm) before and after injection of CO2-saturated water at reservoir conditions (90 bar, 50°C) to image porosity and flow path distribution. During the tracer tests, CT scans were taken at 2.5-minute intervals, and outlet fluid was discretely sampled at the same intervals and subsequently measured via ICP-MS, enabling interpretation of the tracer breakthrough curve through both imaging and geochemical analyses. Comparison of the porosity distribution from before and after injection of CO2 shows an overall decrease in core-averaged porosity from 34% to 31.1%. Permeability decreased exponentially from ~4.9x10-12 m2 to 1.18 x10-12 m2. The decrease in porosity and permeability suggests geochemical transformations in the mineral assemblage of the core, which we observe through petrographic analysis of an unaltered sample of the same lithology in contrast with the altered core. There is a significant increase in grain coatings, as well as reduction in the grain size, suggesting dissolution re-precipitation mechanisms. Finally, to develop a framework for the coupled geochemical and hydrologic responses observed experimentally, we have calibrated a reactive transport model at the core scale using the TOUGHREACT simulator [1]. [1] Xu et al. (2011) Comput. Geosci.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26426063','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26426063"><span>Strong Static Magnetic Fields Increase the Gel Signal in Partially Hydrated DPPC/DMPC Membranes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tang, Jennifer; Alsop, Richard J; Schmalzl, Karin; Epand, Richard M; Rheinstädter, Maikel C</p> <p>2015-09-29</p> <p>NIt was recently reported that static magnetic fields increase lipid order in the hydrophobic membrane core of dehydrated native plant plasma membranes [Poinapen, Soft Matter 9:6804-6813, 2013]. As plasma membranes are multicomponent, highly complex structures, in order to elucidate the origin of this effect, we prepared model membranes consisting of a lipid species with low and high melting temperature. By controlling the temperature, bilayers coexisting of small gel and fluid domains were prepared as a basic model for the plasma membrane core. We studied molecular order in mixed lipid membranes made of dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) using neutron diffraction in the presence of strong static magnetic fields up to 3.5 T. The contribution of the hydrophobic membrane core was highlighted through deuterium labeling the lipid acyl chains. There was no observable effect on lipid organization in fluid or gel domains at high hydration of the membranes. However, lipid order was found to be enhanced at a reduced relative humidity of 43%: a magnetic field of 3.5 T led to an increase of the gel signal in the diffraction patterns of 5%. While all biological materials have weak diamagnetic properties, the corresponding energy is too small to compete against thermal disorder or viscous effects in the case of lipid molecules. We tentatively propose that the interaction between the fatty acid chains' electric moment and the external magnetic field is driving the lipid tails in the hydrophobic membrane core into a better ordered state.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/5711636','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/5711636"><span>Proceedings of the wellbore sampling workshop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Traeger, R.K.; Harding, B.W.</p> <p></p> <p>Representatives from academia, industry and research laboratories participated in an intensive two-day review to identify major technological limitations in obtaining solid and fluid samples from wellbores. Top priorities identified for further development include: coring of hard and unconsolidated materials; flow through fluid samplers with borehole measurements T, P and pH; and nonintrusive interrogation of pressure cores.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160011495','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160011495"><span>Metabolic Potential and Activity in Fluids of the Coast Range Ophiolite Microbial Observatory, California, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoehler, T.; Som, S.; Schrenk, M.; McCollom, T.; Cardace, D.</p> <p>2016-01-01</p> <p>Metabolic potential and activity associated with hydrogen and carbon monoxide were characterized in fluids sampled from the the Coast Range Ophiolite Microbial Observatory (CROMO). CROMO consists of two clusters of science-dedicated wells drilled to varying depths up to 35m in the actively serpentinizing, Jurassic-age Coast Range Ophiolite of Northern California, along with a suite of pre-existing monitoring wells at the same site. Consistent with the fluid chemistry observed in other serpentinizing systems, CROMO fluids are highly alkaline, with pH up to 12.5, high in methane, with concentrations up 1600 micromolar, and low in dissolved inorganic carbon (DIC), with concentrations of 10's to 100's of micromolar. CROMO is conspicuous for fluid H2 concentrations that are consistently sub-micromolar, orders of magnitude lower than is typical of other systems. However, higher H2 concentrations (10's -100's of micromolar) at an earlier stage of fluid chemical evolution are predicted by, or consistent with: thermodynamic models for fluid chemistry based on parent rock composition equivalent to local peridotite and with water:rock ratio constrained by observed pH; the presence of magnetite at several wt% in CROMO drill cores; and concentrations of formate and carbon monoxide that would require elevated H2 if formed in equilibrium with H2 and DIC. Calculated Gibbs energy changes for reaction of H2 and CO in each of several metabolisms, across the range of fluid composition encompassed by the CROMO wells, range from bioenergetically feasible (capable of driving ATP synthesis) to thermodynamically unfavorable. Active consumption relative to killed controls was observed for both CO and H2 during incubation of fluids from the pre-existing monitoring wells; in incubations of freshly cored solids, consumption was only observed in one sample set (corresponding to the lowest pH) out of three. The specific metabolisms by which H2 and CO are consumed remain to be determined.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29260191','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29260191"><span>Effect of Age-Related Human Lens Sutures Growth on Its Fluid Dynamics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Ho-Ting D; Howse, Louisa A; Vaghefi, Ehsan</p> <p>2017-12-01</p> <p>Age-related nuclear cataract is the opacification of the clear ocular lens due to oxidative damage as we age, and is the leading cause of blindness in the world. A lack of antioxidant supply to the core of ever-growing ocular lens could contribute to the cause of this condition. In this project, a computational model was developed to study the sutural fluid inflow of the aging human lens. Three different SOLIDWORKS computational fluid dynamics models of the human lens (7 years old; 28 years old; 46 years old) were created, based on available literature data. The fluid dynamics of the lens sutures were modelled using the Stokes flow equations, combined with realistic physiological boundary conditions and embedded in COMSOL Multiphysics. The flow rate, volume, and flow rate per volume of fluid entering the aging lens were examined, and all increased over the 40 years modelled. However, while the volume of the lens grew by ∼300% and the flow rate increased by ∼400%, the flow rate per volume increased only by very moderate ∼38%. Here, sutural information from humans of 7 to 46 years of age was obtained. In this modelled age range, an increase of flow rate per volume was observed, albeit at very slow rate. We hypothesize that with even further increasing age (60+ years old), the lens volume growth would outpace its flow rate increases, which would eventually lead to malnutrition of the lens nucleus and onset of cataracts.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29183002','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29183002"><span>An MR/MRI compatible core holder with the RF probe immersed in the confining fluid.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shakerian, M; Balcom, B J</p> <p>2018-01-01</p> <p>An open frame RF probe for high pressure and high temperature MR/MRI measurements was designed, fabricated, and tested. The open frame RF probe was installed inside an MR/MRI compatible metallic core holder, withstanding a maximum pressure and temperature of 5000 psi and 80 °C. The open frame RF probe was tunable for both 1 H and 19 F resonance frequencies with a 0.2 T static magnetic field. The open frame structure was based on simple pillars of PEEK polymer upon which the RF probe was wound. The RF probe was immersed in the high pressure confining fluid during operation. The open frame structure simplified fabrication of the RF probe and significantly reduced the amount of polymeric materials in the core holder. This minimized the MR background signal detected. Phase encoding MRI methods were employed to map the spin density of a sulfur hexafluoride gas saturating a Berea core plug in the core holder. The SF 6 was imaged as a high pressure gas and as a supercritical fluid. Copyright © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMagR.286...36S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMagR.286...36S"><span>An MR/MRI compatible core holder with the RF probe immersed in the confining fluid</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shakerian, M.; Balcom, B. J.</p> <p>2018-01-01</p> <p>An open frame RF probe for high pressure and high temperature MR/MRI measurements was designed, fabricated, and tested. The open frame RF probe was installed inside an MR/MRI compatible metallic core holder, withstanding a maximum pressure and temperature of 5000 psi and 80 °C. The open frame RF probe was tunable for both 1H and 19F resonance frequencies with a 0.2 T static magnetic field. The open frame structure was based on simple pillars of PEEK polymer upon which the RF probe was wound. The RF probe was immersed in the high pressure confining fluid during operation. The open frame structure simplified fabrication of the RF probe and significantly reduced the amount of polymeric materials in the core holder. This minimized the MR background signal detected. Phase encoding MRI methods were employed to map the spin density of a sulfur hexafluoride gas saturating a Berea core plug in the core holder. The SF6 was imaged as a high pressure gas and as a supercritical fluid.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70027254','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70027254"><span>A post-Galileo view of Io's interior</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Keszthelyi, L.; Jaeger, W.L.; Turtle, E.P.; Milazzo, M.; Radebaugh, J.</p> <p>2004-01-01</p> <p>We present a self-consistent model for the interior of Io, taking the recent Galileo data into account. In this model, Io has a completely molten core, substantially molten mantle, and a very cold lithosphere. Heat from magmatic activity can mobilize volatile compounds such as SO2 in the lithosphere, and the movement of such cryogenic fluids may be important in the formation of surface features including sapping scarps and paterae. ?? Published by Elsevier Inc.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1513300H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1513300H"><span>Modeling and comparative study of fluid velocities in heterogeneous rocks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hingerl, Ferdinand F.; Romanenko, Konstantin; Pini, Ronny; Balcom, Bruce; Benson, Sally</p> <p>2013-04-01</p> <p>Detailed knowledge of the distribution of effective porosity and fluid velocities in heterogeneous rock samples is crucial for understanding and predicting spatially resolved fluid residence times and kinetic reaction rates of fluid-rock interactions. The applicability of conventional MRI techniques to sedimentary rocks is limited by internal magnetic field gradients and short spin relaxation times. The approach developed at the UNB MRI Centre combines the 13-interval Alternating-Pulsed-Gradient Stimulated-Echo (APGSTE) scheme and three-dimensional Single Point Ramped Imaging with T1 Enhancement (SPRITE). These methods were designed to reduce the errors due to effects of background gradients and fast transverse relaxation. SPRITE is largely immune to time-evolution effects resulting from background gradients, paramagnetic impurities and chemical shift. Using these techniques quantitative 3D porosity maps as well as single-phase fluid velocity fields in sandstone core samples were measured. Using a new Magnetic Resonance Imaging technique developed at the MRI Centre at UNB, we created 3D maps of porosity distributions as well as single-phase fluid velocity distributions of sandstone rock samples. Then, we evaluated the applicability of the Kozeny-Carman relationship for modeling measured fluid velocity distributions in sandstones samples showing meso-scale heterogeneities using two different modeling approaches. The MRI maps were used as reference points for the modeling approaches. For the first modeling approach, we applied the Kozeny-Carman relationship to the porosity distributions and computed respective permeability maps, which in turn provided input for a CFD simulation - using the Stanford CFD code GPRS - to compute averaged velocity maps. The latter were then compared to the measured velocity maps. For the second approach, the measured velocity distributions were used as input for inversely computing permeabilities using the GPRS CFD code. The computed permeabilities were then correlated with the ones based on the porosity maps and the Kozeny-Carman relationship. The findings of the comparative modeling study are discussed and its potential impact on the modeling of fluid residence times and kinetic reaction rates of fluid-rock interactions in rocks containing meso-scale heterogeneities are reviewed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvE..96c2115P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvE..96c2115P"><span>Uhlenbeck-Ford model: Phase diagram and corresponding-states analysis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paula Leite, Rodolfo; Santos-Flórez, Pedro Antonio; de Koning, Maurice</p> <p>2017-09-01</p> <p>Using molecular dynamics simulations and nonequilibrium thermodynamic-integration techniques we compute the Helmholtz free energies of the body-centered-cubic (bcc), face-centered-cubic (fcc), hexagonal close-packed, and fluid phases of the Uhlenbeck-Ford model (UFM) and use the results to construct its phase diagram. The pair interaction associated with the UFM is characterized by an ultrasoft, purely repulsive pair potential that diverges logarithmically at the origin. We find that the bcc and fcc are the only thermodynamically stable crystalline phases in the phase diagram. Furthermore, we report the existence of two reentrant transition sequences as a function of the number density, one featuring a fluid-bcc-fluid succession and another displaying a bcc-fcc-bcc sequence near the triple point. We find strong resemblances to the phase behavior of other soft, purely repulsive systems such as the Gaussian-core model (GCM), inverse-power-law, and Yukawa potentials. In particular, we find that the fcc-bcc-fluid triple point and the phase boundaries in its vicinity are in good agreement with the prediction supplied by a recently proposed corresponding-states principle [J. Chem. Phys. 134, 241101 (2011), 10.1063/1.3605659; Europhys. Lett. 100, 66004 (2012), 10.1209/0295-5075/100/66004]. The particularly strong resemblance between the behavior of the UFM and GCM models are also discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.2804E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.2804E"><span>Preparation of Geophysical Fluid Flow Experiments With The Rotating Spherical Gap Flow Model In Space</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Egbers, C.</p> <p></p> <p>The'GeoFlow' is an ESA experiment planned for the Fluid Science Laboratory on ISS under the scientific coordination (PI) of the Department of Aerodynamics and Fluid Mechanics (LAS) at the Brandenburg Technical University (BTU) of Cottbus, Germany. The objective of the experiment is to study thermal convection in the gap between two concentric rotating (full) spheres. A central symmetric force field simi- lar to the gravity field acting on planets can be produced by applying a high voltage between inner and outer sphere using the dielectrophoretic effect (rotating capacitor). To counter the unidirectional gravity under terrestrial conditions, this experiment re- quires a microgravity environment. The parameters of the experiment are chosen in analogy to the thermal convective motions in the outer core of the Earth. In analogy to geophysical motions in the Earth`s liquid core the experiment can rotate as solid body as well as differential (inner to outer). Thermal convection is produced by heat- ing the inner sphere and cooling the outer ones. Furtheron, the variation of radius ratio between inner and outer sphere is foreseen as a parameter variation. The flows to be investigated will strongly depend on the gap width and on the Prandtl number.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019072','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019072"><span>A sample-freezing drive shoe for a wire line piston core sampler</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Murphy, F.; Herkelrath, W.N.</p> <p>1996-01-01</p> <p>Loss of fluids and samples during retrieval of cores of saturated, noncohesive sediments results in incorrect measures of fluid distributions and an inaccurate measure of the stratigraphic position of the sample. To reduce these errors, we developed a hollow drive shoe that freezes in place the lowest 3 inches (75 mm) of a 1.88-inch-diameter (48 mm), 5-foot-long (1.5 m) sediment sample taken using a commercial wire line piston core sampler. The end of the core is frozen by piping liquid carbon dioxide at ambient temperature through a steel tube from a bottle at the land surface to the drive shoe where it evaporates and expands, cooling the interior surface of the shoe to about -109??F (-78??C). Freezing a core end takes about 10 minutes. The device was used to collect samples for a study of oil-water-air distributions, and for studies of water chemistry and microbial activity in unconsolidated sediments at the site of an oil spill near Bemidji, Minnesota. Before freezing was employed, samples of sandy sediments from near the water table sometimes flowed out of the core barrel as the sampler was withdrawn. Freezing the bottom of the core allowed for the retention of all material that entered the core barrel and lessened the redistribution of fluids within the core. The device is useful in the unsaturated and shallow saturated zones, but does not freeze cores well at depths greater than about 20 feet (6 m) below water, possibly because the feed tube plugs with dry ice with increased exhaust back-pressure, or because sediment enters the annulus between the core barrel and the core barrel liner and blocks the exhaust.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMMR41B0405N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMMR41B0405N"><span>Modeling of carbonate reservoir variable secondary pore space based on CT images</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nie, X.; Nie, S.; Zhang, J.; Zhang, C.; Zhang, Z.</p> <p>2017-12-01</p> <p>Digital core technology has brought convenience to us, and X-ray CT scanning is one of the most common way to obtain 3D digital cores. However, it can only provide the original information of the only samples being scanned, and we can't modify the porosity of the scanned cores. For numerical rock physical simulations, a series of cores with variable porosities are needed to determine the relationship between the physical properties and porosity. In carbonate rocks, the secondary pore space including dissolution pores, caves and natural fractures is the key reservoir space, which makes the study of carbonate secondary porosity very important. To achieve the variation of porosities in one rock sample, based on CT scanned digital cores, according to the physical and chemical properties of carbonate rocks, several mathematical methods are chosen to simulate the variation of secondary pore space. We use the erosion and dilation operations of mathematical morphology method to simulate the pore space changes of dissolution pores and caves. We also use the Fractional Brownian Motion model to generate natural fractures with different widths and angles in digital cores to simulate fractured carbonate rocks. The morphological opening-and-closing operations in mathematical morphology method are used to simulate distribution of fluid in the pore space. The established 3D digital core models with different secondary porosities and water saturation status can be used in the study of the physical property numerical simulations of carbonate reservoir rocks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1266852-vera-cs-modeling-simulation-pwr-main-steam-line-break-core-response-dnb','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1266852-vera-cs-modeling-simulation-pwr-main-steam-line-break-core-response-dnb"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Salko, Robert K; Sung, Yixing; Kucukboyaci, Vefa</p> <p></p> <p>The Virtual Environment for Reactor Applications core simulator (VERA-CS) being developed by the Consortium for the Advanced Simulation of Light Water Reactors (CASL) includes coupled neutronics, thermal-hydraulics, and fuel temperature components with an isotopic depletion capability. The neutronics capability employed is based on MPACT, a three-dimensional (3-D) whole core transport code. The thermal-hydraulics and fuel temperature models are provided by the COBRA-TF (CTF) subchannel code. As part of the CASL development program, the VERA-CS (MPACT/CTF) code system was applied to model and simulate reactor core response with respect to departure from nucleate boiling ratio (DNBR) at the limiting time stepmore » of a postulated pressurized water reactor (PWR) main steamline break (MSLB) event initiated at the hot zero power (HZP), either with offsite power available and the reactor coolant pumps in operation (high-flow case) or without offsite power where the reactor core is cooled through natural circulation (low-flow case). The VERA-CS simulation was based on core boundary conditions from the RETRAN-02 system transient calculations and STAR-CCM+ computational fluid dynamics (CFD) core inlet distribution calculations. The evaluation indicated that the VERA-CS code system is capable of modeling and simulating quasi-steady state reactor core response under the steamline break (SLB) accident condition, the results are insensitive to uncertainties in the inlet flow distributions from the CFD simulations, and the high-flow case is more DNB limiting than the low-flow case.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=Engineering+AND+Mechanics&pg=5&id=EJ1148664','ERIC'); return false;" href="https://eric.ed.gov/?q=Engineering+AND+Mechanics&pg=5&id=EJ1148664"><span>Embedding Hands-On Mini Laboratory Experiences in a Core Undergraduate Fluid Mechanics Course: A Pilot Study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Han, Duanduan; Ugaz, Victor</p> <p>2017-01-01</p> <p>Three self-contained mini-labs were integrated into a core undergraduate fluid mechanics course, with the goal of delivering hands-on content in a manner scalable to large class sizes. These mini-labs supported learning objectives involving friction loss in pipes, flow measurement, and centrifugal pump analysis. The hands-on experiments were…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16632570','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16632570"><span>Voluntary fluid intake and core temperature responses in adolescent tennis players: sports beverage versus water.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bergeron, M F; Waller, J L; Marinik, E L</p> <p>2006-05-01</p> <p>To examine differences in ad libitum fluid intake, comparing a 6% carbohydrate/electrolyte drink (CHO-E) and water, and associated differences in core temperature and other selected physiological and perceptual responses in adolescent athletes during tennis training in the heat. Fourteen healthy, fit, young tennis players (nine male; five female; mean (SD) age 15.1 (1.4) years; weight 60.6 (8.3) kg; height 172.8 (8.6) cm) completed two 120 minute tennis specific training sessions on separate days (randomised, crossover design) in a warm environment (wet bulb globe temperature: CHO-E, 79.3 (2.6) degrees F; water, 79.9 (2.2) degrees F; p>0.05). There were no significant differences (p>0.05) between the trials with respect to fluid intake, urine volume, fluid retention, sweat loss, perceived exertion, thirst, or gastrointestinal discomfort. However, there was a difference (p<0.05) in the percentage body weight change after training (CHO-E, -0.5 (0.7)%; water, -0.9 (0.6)%). Urine specific gravity before training (CHO-E, 1.024 (0.006); water, 1.025 (0.005)) did not correlate significantly (p>0.05) with any of these measurements or with core body temperature. In examining the main effect for trial, the CHO-E trial showed a significantly lower (p<0.001) mean body temperature (irrespective of measurement time) than the water trial. However, the mean body temperature in each trial was not associated (p>0.05) with fluid intake, fluid retention, sweat loss, or percentage body weight change. Ad libitum consumption of a CHO-E drink may be more effective than water in minimising fluid deficits and mean core temperature responses during tennis and other similar training in adolescent athletes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..276a2031R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..276a2031R"><span>Application of foam-extend on turbulent fluid-structure interaction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rege, K.; Hjertager, B. H.</p> <p>2017-12-01</p> <p>Turbulent flow around flexible structures is likely to induce structural vibrations which may eventually lead to fatigue failure. In order to assess the fatigue life of these structures, it is necessary to take the action of the flow on the structure into account, but also the influence of the vibrating structure on the fluid flow. This is achieved by performing fluid-structure interaction (FSI) simulations. In this work, we have investigated the capability of a FSI toolkit for the finite volume computational fluid dynamics software foam-extend to simulate turbulence-induced vibrations of a flexible structure. A large-eddy simulation (LES) turbulence model has been implemented to a basic FSI problem of a flexible wall which is placed in a confined, turbulent flow. This problem was simulated for 2.32 seconds. This short simulation required over 200 computation hours, using 20 processor cores. Thereby, it has been shown that the simulation of FSI with LES is possible, but also computationally demanding. In order to make turbulent FSI simulations with foam-extend more applicable, more sophisticated turbulence models and/or faster FSI iteration schemes should be applied.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGP51A1069L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGP51A1069L"><span>Towards magnetic sounding of the Earth's core by an adjoint method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, K.; Jackson, A.; Livermore, P. W.</p> <p>2013-12-01</p> <p>Earth's magnetic field is generated and sustained by the so called geodynamo system in the core. Measurements of the geomagnetic field taken at the surface, downwards continued through the electrically insulating mantle to the core-mantle boundary (CMB), provide important constraints on the time evolution of the velocity, magnetic field and temperature anomaly in the fluid outer core. The aim of any study in data assimilation applied to the Earth's core is to produce a time-dependent model consistent with these observations [1]. Snapshots of these ``tuned" models provide a window through which the inner workings of the Earth's core, usually hidden from view, can be probed. We apply a variational data assimilation framework to an inertia-free magnetohydrodynamic system (MHD) [2]. Such a model is close to magnetostrophic balance [3], to which we have added viscosity to the dominant forces of Coriolis, pressure, Lorentz and buoyancy, believed to be a good approximation of the Earth's dynamo in the convective time scale. We chose to study the MHD system driven by a static temperature anomaly to mimic the actual inner working of Earth's dynamo system, avoiding at this stage the further complication of solving for the time dependent temperature field. At the heart of the models is a time-dependent magnetic field to which the core-flow is enslaved. In previous work we laid the foundation of the adjoint methodology, applied to a subset of the full equations [4]. As an intermediate step towards our ultimate vision of applying the techniques to a fully dynamic mode of the Earth's core tuned to geomagnetic observations, we present the intermediate step of applying the adjoint technique to the inertia-free Navier-Stokes equation in continuous form. We use synthetic observations derived from evolving a geophysically-reasonable magnetic field profile as the initial condition of our MHD system. Based on our study, we also propose several different strategies for accurately determining the entire trajectory of Earth's geodynamo system. [1] A. Fournier, G. Hulot, D. Jault, W. Kuang, A. Tangborn, N. Gillet, E. Canet, J. Aubert, and F. Lhuillier. An introduction to data assimilation and predictability in geomagnetism. Space. Sci. Rev., 155:247-291, 2010. [2] G. A. Glatzmaier and P. H. Roberts. A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle. Phys. Earth Planet. Inter., 91:63-75, 1995. [3] J. B. Taylor. The magneto-hydrodynamics of a rotating fluid and the earth's dynamo problem. Proc. R. Soc. Lond. A, 274(1357):274-283, 1963. [4] K. Li, A. Jackson, and P. W. Livermore. Variational data assimilation for the initial value dynamo problem. Phys. Rev. E, 84:056321, 2011.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9838B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9838B"><span>3D modeling of carbonates petro-acoustic heterogeneities</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baden, Dawin; Guglielmi, Yves; Saracco, Ginette; Marié, Lionel; Viseur, Sophie</p> <p>2015-04-01</p> <p>Characterizing carbonate reservoirs heterogeneity is a challenging issue for Oil & Gas Industry, CO2 sequestration and all kinds of fluid manipulations in natural reservoirs, due to the significant impact of heterogeneities on fluid flow and storage within the reservoir. Although large scale (> meter) heterogeneities such as layers petrophysical contrasts are well addressed by computing facies-based models, low scale (< meter) heterogeneities are often poorly constrained because of the complexity in predicting their spatial arrangement. In this study, we conducted petro-acoustic measurements on cores of different size and diameter (Ø = 1", 1.5" and 5") in order to evaluate anisotropy or heterogeneity in carbonates at different laboratory scales. Different types of heterogeneities which generally occur in carbonate reservoir units (e.g. petrographic, diagenetic, and tectonic related) were sampled. Dry / wet samples were investigated with different ultrasonic apparatus and using different sensors allowing acoustic characterization through a bandwidth varying from 50 to 500 kHz. Comprehensive measurements realized on each samples allowed statistical analyses of petro-acoustic properties such as attenuation, shear and longitudinal wave velocity. The cores properties (geological and acoustic facies) were modeled in 3D using photogrammetry and GOCAD geo-modeler. This method successfully allowed detecting and imaging in three dimensions differential diagenesis effects characterized by the occurrence of decimeter-scale diagenetic horizons in samples assumed to be homogeneous and/or different diagenetic sequences between shells filling and the packing matrix. We then discuss how small interfaces such as cracks, stylolithes and laminations which are also imaged may have guided these differential effects, considering that understanding the processes may be taken as an analogue to actual fluid drainage complexity in deep carbonate reservoir.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhPl...19e5905K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhPl...19e5905K"><span>First-order finite-Larmor-radius fluid modeling of tearing and relaxation in a plasma pincha)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>King, J. R.; Sovinec, C. R.; Mirnov, V. V.</p> <p>2012-05-01</p> <p>Drift and Hall effects on magnetic tearing, island evolution, and relaxation in pinch configurations are investigated using a non-reduced first-order finite-Larmor-radius (FLR) fluid model with the nonideal magnetohydrodynamics (MHD) with rotation, open discussion (NIMROD) code [C.R. Sovinec and J. R. King, J. Comput. Phys. 229, 5803 (2010)]. An unexpected result with a uniform pressure profile is a drift effect that reduces the growth rate when the ion sound gyroradius (ρs) is smaller than the tearing-layer width. This drift is present only with warm-ion FLR modeling, and analytics show that it arises from ∇B and poloidal curvature represented in the Braginskii gyroviscous stress. Nonlinear single-helicity computations with experimentally relevant ρs values show that the warm-ion gyroviscous effects reduce saturated-island widths. Computations with multiple nonlinearly interacting tearing fluctuations find that m = 1 core-resonant-fluctuation amplitudes are reduced by a factor of two relative to single-fluid modeling by the warm-ion effects. These reduced core-resonant-fluctuation amplitudes compare favorably to edge coil measurements in the Madison Symmetric Torus (MST) reversed-field pinch [R. N. Dexter et al., Fusion Technol. 19, 131 (1991)]. The computations demonstrate that fluctuations induce both MHD- and Hall-dynamo emfs during relaxation events. The presence of a Hall-dynamo emf implies a fluctuation-induced Maxwell stress, and the simulation results show net transport of parallel momentum. The computed magnitude of force densities from the Maxwell and competing Reynolds stresses, and changes in the parallel flow profile, are qualitatively and semi-quantitatively similar to measurements during relaxation in MST.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22072375-first-order-finite-larmor-radius-fluid-modeling-tearing-relaxation-plasma-pinch','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22072375-first-order-finite-larmor-radius-fluid-modeling-tearing-relaxation-plasma-pinch"><span>First-order finite-Larmor-radius fluid modeling of tearing and relaxation in a plasma pinch</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>King, J. R.; Tech-X Corporation, 5621 Arapahoe Ave., Suite A Boulder, Colorado 80303; Sovinec, C. R.</p> <p></p> <p>Drift and Hall effects on magnetic tearing, island evolution, and relaxation in pinch configurations are investigated using a non-reduced first-order finite-Larmor-radius (FLR) fluid model with the nonideal magnetohydrodynamics (MHD) with rotation, open discussion (NIMROD) code [C.R. Sovinec and J. R. King, J. Comput. Phys. 229, 5803 (2010)]. An unexpected result with a uniform pressure profile is a drift effect that reduces the growth rate when the ion sound gyroradius ({rho}{sub s}) is smaller than the tearing-layer width. This drift is present only with warm-ion FLR modeling, and analytics show that it arises from {nabla}B and poloidal curvature represented in themore » Braginskii gyroviscous stress. Nonlinear single-helicity computations with experimentally relevant {rho}{sub s} values show that the warm-ion gyroviscous effects reduce saturated-island widths. Computations with multiple nonlinearly interacting tearing fluctuations find that m = 1 core-resonant-fluctuation amplitudes are reduced by a factor of two relative to single-fluid modeling by the warm-ion effects. These reduced core-resonant-fluctuation amplitudes compare favorably to edge coil measurements in the Madison Symmetric Torus (MST) reversed-field pinch [R. N. Dexter et al., Fusion Technol. 19, 131 (1991)]. The computations demonstrate that fluctuations induce both MHD- and Hall-dynamo emfs during relaxation events. The presence of a Hall-dynamo emf implies a fluctuation-induced Maxwell stress, and the simulation results show net transport of parallel momentum. The computed magnitude of force densities from the Maxwell and competing Reynolds stresses, and changes in the parallel flow profile, are qualitatively and semi-quantitatively similar to measurements during relaxation in MST.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24450335','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24450335"><span>Comparative evaluation of the indigenous microbial diversity vs. drilling fluid contaminants in the NEEM Greenland ice core.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miteva, Vanya; Burlingame, Caroline; Sowers, Todd; Brenchley, Jean</p> <p>2014-08-01</p> <p>Demonstrating that the detected microbial diversity in nonaseptically drilled deep ice cores is truly indigenous is challenging because of potential contamination with exogenous microbial cells. The NEEM Greenland ice core project provided a first-time opportunity to determine the origin and extent of contamination throughout drilling. We performed multiple parallel cultivation and culture-independent analyses of five decontaminated ice core samples from different depths (100-2051 m), the drilling fluid and its components Estisol and Coasol, and the drilling chips collected during drilling. We created a collection of diverse bacterial and fungal isolates (84 from the drilling fluid and its components, 45 from decontaminated ice, and 66 from drilling chips). Their categorization as contaminants or intrinsic glacial ice microorganisms was based on several criteria, including phylogenetic analyses, genomic fingerprinting, phenotypic characteristics, and presence in drilling fluid, chips, and/or ice. Firmicutes and fungi comprised the dominant group of contaminants among isolates and cloned rRNA genes. Conversely, most Proteobacteria and Actinobacteria originating from the ice were identified as intrinsic. This study provides a database of potential contaminants useful for future studies of NEEM cores and can contribute toward developing standardized protocols for contamination detection and ensuring the authenticity of the microbial diversity in deep glacial ice. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28498010','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28498010"><span>From play to problem solving to Common Core: The development of fluid reasoning.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prince, Pauline</p> <p>2017-01-01</p> <p>How and when does fluid reasoning develop and what does it look like at different ages, from a neurodevelopmental and functional perspective? The goal of this article is to discuss the development of fluid reasoning from a practical perspective of our children's lives: from play to problem solving to Common Core Curriculum. A review of relevant and current literature supports a connection between movement, including movement through free play, and the development of novel problem solving. As our children grow and develop, motor routines can become cognitive routines and can be evidenced not only in games, such as chess, but also in the acquisition and demonstration of academic skills. Finally, this article describes the connection between novel problem solving and the demands of the Common Core Curriculum.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PEPI..152...22B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PEPI..152...22B"><span>Numerical models of the Earth’s thermal history: Effects of inner-core solidification and core potassium</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butler, S. L.; Peltier, W. R.; Costin, S. O.</p> <p>2005-09-01</p> <p>Recently there has been renewed interest in the evolution of the inner core and in the possibility that radioactive potassium might be found in significant quantities in the core. The arguments for core potassium come from considerations of the age of the inner core and the energy required to sustain the geodynamo [Nimmo, F., Price, G.D., Brodholt, J., Gubbins, D., 2004. The influence of potassium on core and geodynamo evolution. Geophys. J. Int. 156, 363-376; Labrosse, S., Poirier, J.-P., Le Mouël, J.-L., 2001. The age of the inner core. Earth Planet Sci. Lett. 190, 111-123; Labrosse, S., 2003. Thermal and magnetic evolution of the Earth's core. Phys. Earth Planet Int. 140, 127-143; Buffett, B.A., 2003. The thermal state of Earth's core. Science 299, 1675-1677] and from new high pressure physics analyses [Lee, K., Jeanloz, R., 2003. High-pressure alloying of potassium and iron: radioactivity in the Earth's core? Geophys. Res. Lett. 30 (23); Murthy, V.M., van Westrenen, W., Fei, Y.W., 2003. Experimental evidence that potassium is a substantial radioactive heat source in planetary cores. Nature 423, 163-165; Gessmann, C.K., Wood, B.J., 2002. Potassium in the Earth's core? Earth Planet Sci. Lett. 200, 63-78]. The Earth's core is also located at the lower boundary of the convecting mantle and the presence of radioactive heat sources in the core will affect the flux of heat between these two regions and will, as a result, have a significant impact on the Earth's thermal history. In this paper, we present Earth thermal history simulations in which we calculate fluid flow in a spherical shell representing the mantle, coupled with a core of a given heat capacity with varying degrees of internal heating in the form of K40 and varying initial core temperatures. The mantle model includes the effects of the temperature dependence of viscosity, decaying radioactive heat sources, and mantle phase transitions. The core model includes the thermal effects of inner core solidification and we present models for which the final size of the inner core is the same that for the present-day Earth. We compare the results of simulations with and without the effects of inner core solidification and we compare the results of the numerical model with those of a parameterized model. Models with concentrations of potassium in the core of roughly 600 ppm best satisfy the present-day surface heat flow constraint; however, the core temperatures in these models are somewhat high. In addition, we find that models with lesser degrees of heating in the core can also satisfy the surface heat flow constraint provided that the mantle is in a particularly active state. Our models predict a relatively young inner core with the greatest age being 1756 Ma. We demonstrate that models with high core temperatures in the latter part of simulations result in high CMB heat flows which lead to predictions of young inner cores. For fixed initial core temperatures, this leads to a slight decrease in the predicted age of the inner core with increasing concentration of radioactive elements in the core.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140009122','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140009122"><span>A Cryogenic Fluid System Simulation in Support of Integrated Systems Health Management</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barber, John P.; Johnston, Kyle B.; Daigle, Matthew</p> <p>2013-01-01</p> <p>Simulations serve as important tools throughout the design and operation of engineering systems. In the context of sys-tems health management, simulations serve many uses. For one, the underlying physical models can be used by model-based health management tools to develop diagnostic and prognostic models. These simulations should incorporate both nominal and faulty behavior with the ability to inject various faults into the system. Such simulations can there-fore be used for operator training, for both nominal and faulty situations, as well as for developing and prototyping health management algorithms. In this paper, we describe a methodology for building such simulations. We discuss the design decisions and tools used to build a simulation of a cryogenic fluid test bed, and how it serves as a core technology for systems health management development and maturation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130001802','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130001802"><span>Thermal Hydraulics Design and Analysis Methodology for a Solid-Core Nuclear Thermal Rocket Engine Thrust Chamber</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Ten-See; Canabal, Francisco; Chen, Yen-Sen; Cheng, Gary; Ito, Yasushi</p> <p>2013-01-01</p> <p>Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions. This chapter describes a thermal hydraulics design and analysis methodology developed at the NASA Marshall Space Flight Center, in support of the nuclear thermal propulsion development effort. The objective of this campaign is to bridge the design methods in the Rover/NERVA era, with a modern computational fluid dynamics and heat transfer methodology, to predict thermal, fluid, and hydrogen environments of a hypothetical solid-core, nuclear thermal engine the Small Engine, designed in the 1960s. The computational methodology is based on an unstructured-grid, pressure-based, all speeds, chemically reacting, computational fluid dynamics and heat transfer platform, while formulations of flow and heat transfer through porous and solid media were implemented to describe those of hydrogen flow channels inside the solid24 core. Design analyses of a single flow element and the entire solid-core thrust chamber of the Small Engine were performed and the results are presented herein</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740019617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740019617"><span>Apparatus for establishing flow of a fluid mass having a known velocity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Price, P.; Veikins, O.; Bate, E. R., Jr.; Jones, R. H. (Inventor)</p> <p>1974-01-01</p> <p>An apparatus for establishing a flow of fluid mass, such as gas, having a known velocity is introduced. The apparatus is characterized by an hermetically sealed chamber conforming to a closed-loop configuration and including a throat and a plurality of axially displaceable pistons for sweeping through the throat a stream of gas including a core and an unsheared boundary layer. Within the throat there is a cylindrical coring body concentrically related to the throat for receiving the core, and a chamber surrounding the cylindrical body for drawing off the boundary layer, whereby the velocity of the core is liberated from the effects of the velocity of the boundary layer.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H11H1005V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H11H1005V"><span>Integrated Experimental and Computational Study of Hydraulic Fracturing and the Use of Alternative Fracking Fluids</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viswanathan, H.; Carey, J. W.; Karra, S.; Porter, M. L.; Rougier, E.; Zhang, D.; Makedonska, N.; Middleton, R. S.; Currier, R.; Gupta, R.; Lei, Z.; Kang, Q.; O'Malley, D.; Hyman, J.</p> <p>2014-12-01</p> <p>Shale gas is an unconventional fossil energy resource that is already having a profound impact on US energy independence and is projected to last for at least 100 years. Production of methane and other hydrocarbons from low permeability shale involves hydrofracturing of rock, establishing fracture connectivity, and multiphase fluid-flow and reaction processes all of which are poorly understood. The result is inefficient extraction with many environmental concerns. A science-based capability is required to quantify the governing mesoscale fluid-solid interactions, including microstructural control of fracture patterns and the interaction of engineered fluids with hydrocarbon flow. These interactions depend on coupled thermo-hydro-mechanical-chemical (THMC) processes over scales from microns to tens of meters. Determining the key mechanisms in subsurface THMC systems has been impeded due to the lack of sophisticated experimental methods to measure fracture aperture and connectivity, multiphase permeability, and chemical exchange capacities at the high temperature, pressure, and stresses present in the subsurface. This project uses innovative high-pressure microfluidic and triaxial core flood experiments on shale to explore fracture-permeability relations and the extraction of hydrocarbon. These data are integrated with simulations including lattice Boltzmann modeling of pore-scale processes, finite-element/discrete element models of fracture development in the near-well environment, discrete-fracture modeling of the reservoir, and system-scale models to assess the economics of alternative fracturing fluids. The ultimate goal is to make the necessary measurements to develop models that can be used to determine the reservoir operating conditions necessary to gain a degree of control over fracture generation, fluid flow, and interfacial processes over a range of subsurface conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvD..95b4022S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvD..95b4022S"><span>Gravitational wave transient signal emission via Ekman pumping in neutron stars during post-glitch relaxation phase</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Avneet</p> <p>2017-01-01</p> <p>Glitches in the rotational frequency of a spinning neutron star could be promising sources of gravitational wave signals lasting between a few microseconds to a few weeks. The emitted signals and their properties depend upon the internal properties of the neutron star. In neutron stars, the most important physical properties of the fluid core are the viscosity of the fluid, the stratification of flow in the equilibrium state, and the adiabatic sound speed. Such models were previously studied [C. A. van Eysden and A. Melatos, Classical Quantum Gravity 25, 225020 (2008, 10.1088/0264-9381/25/22/225020); M. F. Bennett, C. A. van Eysden, and A. Melatos, Mon. Not. R. Astron. Soc. 409, 1705 (2010), 10.1111/j.1365-2966.2010.17416.x] following simple assumptions on all contributing factors, in which the post-glitch relaxation phase could be driven by the well-known process of Ekman pumping [G. Walin, J. Fluid Mech. 36, 289 (1969, 10.1017/S0022112069001662); M. Abney and R. I. Epstein, J. Fluid Mech. 312, 327 (1996), 10.1017/S0022112096002030]. We explore the hydrodynamic properties of the flow of fluid during this phase following more relaxed assumptions on the stratification of flow and the pressure-density gradients within the neutron star than previously studied. We calculate the time scales of duration as well as the amplitudes of the resulting gravitational wave signals, and we detail their dependence on the physical properties of the fluid core. We find that it is possible for the neutron star to emit gravitational wave signals in a wide range of decay time scales and within the detection sensitivity of aLIGO for selected domains of physical parameters.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160013543&hterms=Tidal+waves&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTidal%2Bwaves','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160013543&hterms=Tidal+waves&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTidal%2Bwaves"><span>Resonant Tidal Excitation of Internal Waves in the Earth's Fluid Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tyler, Robert H.; Kuang, Weijia</p> <p>2014-01-01</p> <p>It has long been speculated that there is a stably stratified layer below the core-mantle boundary, and two recent studies have improved the constraints on the parameters describing this stratification. Here we consider the dynamical implications of this layer using a simplified model. We first show that the stratification in this surface layer has sensitive control over the rate at which tidal energy is transferred to the core. We then show that when the stratification parameters from the recent studies are used in this model, a resonant configuration arrives whereby tidal forces perform elevated rates of work in exciting core flow. Specifically, the internal wave speed derived from the two independent studies (150 and 155 m/s) are in remarkable agreement with the speed (152 m/s) required for excitation of the primary normal mode of oscillation as calculated from full solutions of the Laplace Tidal Equations applied to a reduced-gravity idealized model representing the stratified layer. In evaluating this agreement it is noteworthy that the idealized model assumed may be regarded as the most reduced representation of the stratified dynamics of the layer, in that there are no non-essential dynamical terms in the governing equations assumed. While it is certainly possible that a more realistic treatment may require additional dynamical terms or coupling, it is also clear that this reduced representation includes no freedom for coercing the correlation described. This suggests that one must accept either (1) that tidal forces resonantly excite core flow and this is predicted by a simple model or (2) that either the independent estimates or the dynamical model does not accurately portray the core surface layer and there has simply been an unlikely coincidence between three estimates of a stratification parameter which would otherwise have a broad plausible range.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P33D2908M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P33D2908M"><span>Characterization of Fractures in the Chicxulub Peak Ring: Preliminary Results from IODP/ICDP Expedition 364</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCall, N.; Gulick, S. P. S.; Morgan, J. V.; Hall, B. J.; Jones, L.; Expedition 364 Science Party, I. I.</p> <p>2017-12-01</p> <p>During Expedition 364, IODP/ICDP drilled the peak ring of the Chicxulub impact crater at Site M0077, recovering core from 505.7 to 1334.7 mbsf. The core has been imaged via X-ray Computer Tomography (CT) as a noninvasive method to create a 3-dimensional model of the core, providing information on the density and internal structure at a 0.3 mm resolution. Results from the expedition show that from 748 mbsf and deeper the peak ring is largely composed of uplifted and fractured granitic basement rocks originally sourced from approximately 8-10 km depth. Impact crater modeling suggests the peak ring was formed through dynamic collapse of a rebounding central peak within 10 minutes of impact, requiring the target rocks to temporarily behave as a viscous fluid. The newly recovered core provides a rare opportunity to investigate the cratering process, specifically how the granite was weakened, as well as the extent of the hydrothermal system created after the impact. Based on the CT data, we identify four classes of fractures based on their CT facies deforming the granitoids: pervasive fine fractures, discrete fine fractures, discrete filled fractures, and discrete open fractures. Pervasive fine fractures were most commonly found proximal to dikes and impact melt rock. Discrete filled fractures often displayed a cataclastic texture. We present density trends for the different facies and compare these to petrophysical properties (density, NGR, P-wave seismic velocity). Fractured areas have a lower density than the surrounding granite, as do most filled fractures. This reduction suggests that fluid migrating through the peak ring in the wake of the impact either deposited lower density minerals within the fractures and/or altered the original fracture fill. The extent and duration of fluid flow recorded in these fractures will assist in the characterization of the post-impact hydrothermal system. Future work includes combining information from CT images with thin sections and plug samples at similar depths, refinement of CT facies characterization, examining cross-cutting relationships to determine timing constraints of deformation processes, and measurement of the orientation of the fractures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19..610J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19..610J"><span>Numerical simulation based on core analysis of a single fracture in an Enhanced Geothermal System</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jarrahi, Miad; Holländer, Hartmut</p> <p>2017-04-01</p> <p>The permeability of reservoirs is widely affected by the presence of fractures dispersed within them, as they form superior paths for fluid flow. Core analysis studies the fractures characteristics and explains the fluid-rock interactions to provide the information of permeability and saturation of a hydraulic fracturing reservoir or an enhanced geothermal system (EGS). This study conducted numerical simulations of a single fracture in a Granite core obtained from a depth of 1890 m in borehole EPS1 from Soultz-sous-Forêts, France. Blaisonneau et al. (2016) designed the apparatus to investigate the complex physical phenomena on this cylindrical sample. The method of the tests was to percolate a fluid through a natural fracture contained in a rock sample, under controlled thermo-hydro-mechanical conditions. A divergent radial flow within the fracture occurred due to the injection of fluid into the center of the fracture. The tests were performed within a containment cell with a normal stress of 2.6, 4.9, 7.2 and 9.4 MPa loading on the sample perpendicular to the fracture plane. This experiment was numerically performed to provide an efficient numerical method by modeling single phase flow in between the fracture walls. Detailed morphological features of the fracture such as tortuosity and roughness, were obtained by image processing. The results included injection pressure plots with respect to injection flow rate. Consequently, by utilizing Hagen-Poiseuille's cubic law, the equivalent hydraulic aperture size, of the fracture was derived. Then, as the sample is cylindrical, to modify the Hagen-Poiseuille's cubic law for circular parallel plates, the geometric relation was applied to obtain modified hydraulic aperture size. Finally, intrinsic permeability of the fracture under each mechanical normal stress was evaluated based on modified hydraulic aperture size. The results were presented in two different scenarios, before and after reactive percolation test, to demonstrate the effect of chemical reactive flow. The fracture after percolation test showed larger equivalent aperture size and higher permeability. Additionally, the higher the normal stress, the lower permeability was investigated. This confirmed the permeability evolution due to chemical percolation and mechanical loading. All results showed good agreements with corresponding experimental results provided by Blaisonneau et al. (2016). Keyword: Core analysis, Hydraulic fracturing, Enhanced geothermal system, Permeability, Fluid-rock interactions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.T13A1911A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.T13A1911A"><span>Helium isotopes in matrix pore fluids from SAFOD drill core samples suggest mantle fluids cannot be responsible for fault weakening</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ali, S.; Stute, M.; Torgersen, T.; Winckler, G.</p> <p>2008-12-01</p> <p>To quantify fluid flow in the San Andreas Fault (SAF) (and since direct fracture fluid sampling of the fault zone was not available), we have adapted a method to extract rare gases from matrix fluids of whole rocks by diffusion. Helium was measured on drill core samples obtained from 3054 m (Pacific Plate) to 3990 m (North American Plate) through the San Andreas Fault Zone (SAFZ) ~3300 m during SAFOD Phases I (2004), II (2005), III (2007). Samples were typically collected as 2.54 cm diameter subcores drilled into the ends of the cores, or from the core catcher and drillcore fragments within <2hr after core recovery. The samples were placed into ultra high vacuum stainless steel containers, flushed with ultra high purity nitrogen and immediately evacuated. Helium isotopes of the extracted matrix pore fluids and the solid matrix were determined by mass spectrometery at LDEO. Matrix porefluid 3He/4He ratios are ~0.4 - 0.5xRa (Ra: atmospheric 3He/4He = 1.384 x 10-6) in the Pacific Plate, increasing toward the SAFZ, while pore fluids in the North American Plate have a 3He/4He range of 0.7-0.9Ra, increasing away from the SAFZ (consistent with results from mud gas samples (Wiersberg and Erzinger, 2007) and direct fluid samples (Kennedy et al., 2007)). Helium isotope ratios of the solid matrix are less than 0.06Ra across the SAF in samples from both the North American and the Pacific plates, thereby excluding the host matrix as source for the enhanced isotopic signature. If the system is assumed to be in steady state, then the flux of mantle helium must be from the North American Plate to the Pacific plate. The steeper gradient in the Pacific Plate relative to the North American plate is consistent with a porosity corrected effective diffusivity. The source for this mantle helium in the North American Plate is likely related to a low crustal conductivity zone identified by magnetotelluric signals (Becken et al., 2008) that provides a channel for transport of mantle helium within brittle crust under high strain rates (Kennedy et al., 2007). The helium isotope gradients suggest that fault weakening by mantle-derived fluid pressure is unlikely. More likely, mantle fluids "bleed" into the North American plate below seismogenic depths and are transported across the fault by nonseismic, diffusive processes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17788230','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17788230"><span>Precession of the Earth as the Cause of Geomagnetism: Experiments lend support to the proposal that precessional torques drive the earth's dynamo.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Malkus, W V</p> <p>1968-04-19</p> <p>I have proposed that the precessional torques acting on the earth can sustain a turbulent hydromagnetic flow in the molten core. A gross balance of the Coriolis force, the Lorentz force, and the precessional force in the core fluid provided estimates of the fluid velocity and the interior magnetic field characteristic of such flow. Then these numbers and a balance of the processes responsible for the decay and regeneration of the magnetic field provided an estimate of the magnetic field external to the core. This external field is in keeping with the observations, but its value is dependent upon the speculative value for the electrical conductivity of core material. The proposal that turbulent flow due to precession can occur in the core was tested in a study of nonmagnetic laboratory flows induced by the steady precession of fluid-filled rotating spheroids. It was found that these flows exhibit both small wavelike instabilities and violent finite-amplitude instability to turbulent motion above critical values of the precession rate. The observed critical parameters indicate that a laminar flow in the core, due to the earth's precession, would have weak hydrodynamic instabilities at most, but that finite-amplitude hydromagnetic instability could lead to fully turbulent flow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP13A1582W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP13A1582W"><span>Ca Isotope Geochemistry in Marine Deep Sea Sediments of the Eastern Pacific</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wittke, A.; Gussone, N. C.; Derigs, D.; Schälling, M.; Teichert, B. M.</p> <p>2017-12-01</p> <p>Ca isotope ratio analysis (δ44/40Ca) is a powerful tool to investigate diagenetic reactions in marine sedimentary porewater systems, as it is sensitive to processes such as carbonate dissolution, precipitation, recrystallization, ion exchange and deep fluid sources, due to the isotopic difference between dissolved Ca and solid carbonate minerals (e.g. [1];[2]). We analyzed eight sediment cores of the (paleo-) Pacific equatorial age transect. Two sediment cores show decreasing Ca isotope profiles starting at the sediment/water interface with seawater-like values down to sediment-like values due to recrystallization and an increasing in the bottom part again to seawater-like values. The other studied cores show different degrees of flattening of this middle bulge. We interpret this pattern either as an effect of sediment composition and thickness, decreasing recrystallization rates and/or fluid flux or a combination of all of these factors at the respective sampling sites. Element concentration profiles and Sr-isotope variations on some of these sediment cores show a similar behavior, supporting our findings ([3]; [4]). Seawater influx at (inactive) seamounts is supposed to cause seawater-like values at the bottom of the sediment cores by fluids migrating through the oceanic basement (e.g. [5]). While [6] hypothesizes that two seamounts or bathymetric pits are connected, with a recharge and a discharge site [7] say that uptaken fluids could be released through the surrounding seafloor as well due to diffusive exchange with the underlying oceanic crust. Our Ca isotope results combined with a transport reaction model approach support the latter hypothesis. References: [1] Teichert B. M., Gussone N. and Torres M. E. (2009) [2] Ockert C., Gussone N., Kaufhold S. and Teichert B. (2013) [3] Pälike H., Lyle M., Nishi H., Raffi I., Gamage K. and Klaus A. (eds.) (2010) [4] Voigt J., Hathorne E. C., Frank M., Vollstaedt H. and Eisenhauer A. (2015) [5] Villinger H. W., Pichler T., Kaul N., Stephan S., Pälike H. and Stephan F. (2017) [6] Bekins B. A., Spivack A. J., Davis E. E. and Mayer L. A. (2007) [7] Mewes K., Mogollón J. M., Picard A., Rühlemann C., Eisenhauer A., Kuhn T., Ziebis W. and Kasten S. (2016)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950021871','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950021871"><span>Designing for time-dependent material response in spacecraft structures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hyer, M. W.; Oleksuk, Lynda L. S.; Bowles, D. E.</p> <p>1992-01-01</p> <p>To study the influence on overall deformations of the time-dependent constitutive properties of fiber-reinforced polymeric matrix composite materials being considered for use in orbiting precision segmented reflectors, simple sandwich beam models are developed. The beam models include layers representing the face sheets, the core, and the adhesive bonding of the face sheets to the core. A three-layer model lumps the adhesive layers with the face sheets or core, while a five-layer model considers the adhesive layers explicitly. The deformation response of the three-layer and five-layer sandwich beam models to a midspan point load is studied. This elementary loading leads to a simple analysis, and it is easy to create this loading in the laboratory. Using the correspondence principle of viscoelasticity, the models representing the elastic behavior of the two beams are transformed into time-dependent models. Representative cases of time-dependent material behavior for the facesheet material, the core material, and the adhesive are used to evaluate the influence of these constituents being time-dependent on the deformations of the beam. As an example of the results presented, if it assumed that, as a worst case, the polymer-dominated shear properties of the core behave as a Maxwell fluid such that under constant shear stress the shear strain increases by a factor of 10 in 20 years, then it is shown that the beam deflection increases by a factor of 1.4 during that time. In addition to quantitative conclusions, several assumptions are discussed which simplify the analyses for use with more complicated material models. Finally, it is shown that the simpler three-layer model suffices in many situations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010MMTB...41.1354A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010MMTB...41.1354A"><span>Computational Fluid Dynamics Modeling of Supersonic Coherent Jets for Electric Arc Furnace Steelmaking Process</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alam, Morshed; Naser, Jamal; Brooks, Geoffrey; Fontana, Andrea</p> <p>2010-12-01</p> <p>Supersonic coherent gas jets are now used widely in electric arc furnace steelmaking and many other industrial applications to increase the gas-liquid mixing, reaction rates, and energy efficiency of the process. However, there has been limited research on the basic physics of supersonic coherent jets. In the present study, computational fluid dynamics (CFD) simulation of the supersonic jet with and without a shrouding flame at room ambient temperature was carried out and validated against experimental data. The numerical results show that the potential core length of the supersonic oxygen and nitrogen jet with shrouding flame is more than four times and three times longer, respectively, than that without flame shrouding, which is in good agreement with the experimental data. The spreading rate of the supersonic jet decreased dramatically with the use of the shrouding flame compared with a conventional supersonic jet. The present CFD model was used to investigate the characteristics of the supersonic coherent oxygen jet at steelmaking conditions of around 1700 K (1427 °C). The potential core length of the supersonic coherent oxygen jet at steelmaking conditions was 1.4 times longer than that at room ambient temperature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFDQ14009G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFDQ14009G"><span>Three-dimensional investigations of the threading regime in a microfluidic flow-focusing channel</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gowda, Krishne; Brouzet, Christophe; Lefranc, Thibault; Soderberg, L. Daniel; Lundell, Fredrik</p> <p>2017-11-01</p> <p>We study the flow dynamics of the threading regime in a microfluidic flow-focusing channel through 3D numerical simulations and experiments. Making strong filaments from cellulose nano-fibrils (CNF) could potentially steer to new high-performance bio-based composites competing with conventional glass fibre composites. CNF filaments can be obtained through hydrodynamic alignment of dispersed CNF by using the concept of flow-focusing. The aligned structure is locked by diffusion of ions resulting in a dispersion-gel transition. Flow-focusing typically refers to a microfluidic channel system where the core fluid is focused by the two sheath fluids, thereby creating an extensional flow at the intersection. In this study, threading regime corresponds to an extensional flow field generated by the water sheath fluid stretching the dispersed CNF core fluid and leading to formation of long threads. The experimental measurements are performed using optical coherence tomography (OCT) and 3D numerical simulations with OpenFOAM. The prime focus is laid on the 3D characteristics of thread formation such as wetting length of core fluid, shape, aspect ratio of the thread and velocity flow-field in the microfluidic channel.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H34E..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H34E..02B"><span>Emerging Methods in Sub Core-Scale Imaging and Characterization of the Influence of Heterogeneity on Flow in Rocks (Invited)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benson, S. M.; Hingerl, F.; Pini, R.</p> <p>2013-12-01</p> <p>New imaging techniques and approaches are providing unparalleled insight into the influence of sub-core scale heterogeneities on single and multiphase flows. Quantification of sub core-scale porosity, permeability, and even capillary pressure curves at a spatial scale of about 1-10 cubic millimeters is now possible. This scale provides a critical link in the continuum of spatial scales needed to link pore-scale processes to core-scale and field scale flow and transport. Data from such studies can be used to directly test the veracity of models for flow and transport in heterogeneous rocks, provide data for multi-stage upscaling, and reveal insights about physical/chemical processes heretofore neglected. Here we present data from three emerging techniques capable of imaging and quantifying transport properties and phenomena at the sub-core scale: magnetic resonance imaging (MRI); positron emission tomography (PET); and X-Ray CT scanning. Direct imaging of spatially resolved fluid velocities and porosity is possible with MRI (Romanenko et al., 2012). These data can be inverted to provide permeability and porosity maps at a spatial scale of ~10 cubic millimeter. PET imaging can be used to track movement of a radioactive tracer through a rock and simultaneously measure effluent tracer concentrations at a similar resolution (Boutchko et al., 2012). X-ray CT scanning of multiphase flow experiments can be used to measure capillary pressure curves and through scaling relationships, to calculate permeability at a scale of about 1 cubic millimeters(Krause et al., 2011; Pini et al., 2013). Strengths and shortcomings of these techniques are discussed--along with the benefits of combining them. Together these techniques provide a new platform from which to probe more deeply the ubiquitous influence of heterogeneity on subsurface flow and transport processes, and ultimately improve predictions of subsurface transport. Boutchk et al., 2012. Imaging and modeling of flow in porous media using clinical nuclear emission tomography systems and computational fluid dynamics. Journal of Applied geophysics, 76, 74-81. Krause, M.H., J.C. Perrin, and S.M. Benson, 2011. Modeling permeability distributions in a sandstone core for history matching core flood experiments, SPE Journal, 16, 768-777. Pini R. and Benson S., Characterization and scaling of meso-scale heterogeneities in sandstones. Geophysical Research Letters, 2013, 40. Romanenko, K., and Balscom, Permeability mapping in naturally heterogeneous sandstone cores with magnetization prepared SPRITE, 2012, 58, 3916-3926.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100038444','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100038444"><span>Performance Analysis of Scientific and Engineering Applications Using MPInside and TAU</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Saini, Subhash; Mehrotra, Piyush; Taylor, Kenichi Jun Haeng; Shende, Sameer Suresh; Biswas, Rupak</p> <p>2010-01-01</p> <p>In this paper, we present performance analysis of two NASA applications using performance tools like Tuning and Analysis Utilities (TAU) and SGI MPInside. MITgcmUV and OVERFLOW are two production-quality applications used extensively by scientists and engineers at NASA. MITgcmUV is a global ocean simulation model, developed by the Estimating the Circulation and Climate of the Ocean (ECCO) Consortium, for solving the fluid equations of motion using the hydrostatic approximation. OVERFLOW is a general-purpose Navier-Stokes solver for computational fluid dynamics (CFD) problems. Using these tools, we analyze the MPI functions (MPI_Sendrecv, MPI_Bcast, MPI_Reduce, MPI_Allreduce, MPI_Barrier, etc.) with respect to message size of each rank, time consumed by each function, and how ranks communicate. MPI communication is further analyzed by studying the performance of MPI functions used in these two applications as a function of message size and number of cores. Finally, we present the compute time, communication time, and I/O time as a function of the number of cores.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175940','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175940"><span>Apparatus and method for controlling the temperature of the core of a super-conducting transformer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Golner, Thomas; Pleva, Edward; Mehta, Shirish</p> <p>2006-10-10</p> <p>An apparatus for controlling the temperature of a core of a transformer is provided that includes a core, a shield surrounding the core, a cast formed between the core and the shield, and tubing positioned on the shield. The cast directs heat from the core to the shield and cooling fluid is directed through the tubing to cool the shield.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869465','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869465"><span>Method and apparatus utilizing ionizing and microwave radiation for saturation determination of water, oil and a gas in a core sample</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Maerefat, Nicida L.; Parmeswar, Ravi; Brinkmeyer, Alan D.; Honarpour, Mehdi</p> <p>1994-01-01</p> <p>A system for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample. The condensation of heavy hydrocarbon gas and the dynamic characteristics of the fluids are observed with a sight glass at the outlet of the core sample.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15789730','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15789730"><span>Designing optical-fiber modulators by using magnetic fluids.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Horng, H E; Chieh, J J; Chao, Y H; Yang, S Y; Hong, Chin-Yih; Yang, H C</p> <p>2005-03-01</p> <p>To reduce interface loss between optical fibers and devices in telecommunication systems, the development of an optical-fiber-based device that can be fused directly with fibers is important. A novel optical modulator consisting of a bare fiber core surrounded by magnetic fluids instead of by a SiO2 cladding layer is proposed. Applying a magnetic field raises the refractive index of the magnetic fluid. Thus we can control the occurrence of total reflection at the interface between the fiber core and the magnetic fluid when light propagates along the fiber. As a result, the intensity of the outgoing light is modulated by variation in field strength. Details of the design, fabrication, and working properties of such a modulator are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H41P..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H41P..04L"><span>The effect of CO2-fluid-rock interactions on the porosity and permeability of calcite-bearing sandstone</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamy-Chappuis, B.; Yardley, B.; Grattoni, C.</p> <p>2013-12-01</p> <p>Brine acidification following CO2 dissolution will initiate fluid-rock interactions that could significantly modify porosity, permeability and therefore the capacity and injectivity of a reservoir. We have investigated experimentally the dissolution of calcite in sandstone cores injected with CO2-saturated brine, and the effect this has on permeability. A series of CT (Computerized Tomography) - monitored experiments were conducted on a Jurassic sandstone (porosity = 30%, permeability = 10mD, calcite content = 5% in the form of dispersed shell fragments). Brine saturated with CO2 at pressures up to 1 MPa was injected into 5cm long, 3.75cm diameter cores at a flow rate of 1 ml/min and room temperature. The data showed quasi-instantaneous dissolution of the calcite even at low CO2 concentrations (0.15 Molar) and high fluid interstitial velocities (1mm/s), with the migration of a calcite dissolution front through the core recorded by successive CT scans. The resulting permeability increase was 60 - 80% whereas the predicted permeability change for the observed increase in porosity is only 10 - 20% using the Kozeny-Carman relationship. This result is particularly significant because the effect of porosity increase on permeability is usually modelled with this relationship, irrespective of the mechanism of porosity increase. Micro-CT scans (pixel resolution: 2.5 microns) of unreacted cores were used to generate 3D porosity models with calcite either treated as solid (pre-reaction model) or converted to pores (post-reaction model). FLUENT simulations performed using these models predicted the observed large relative changes in permeability with calcite dissolution but overestimated absolute permeability by an order of magnitude. This was probably due to the scan resolution being too coarse to correctly model pore throats. The observed large change in permeability for a small change in porosity may have resulted from increase in connectivity, focused dissolution at the pore throats or reduction in tortuosity. SEM (Scanning Electron Microscope) imaging demonstrates dissolution of relatively large isolated shell fragments but this had little effect on the overall connectivity. No calcite cement was observed at the pore throats in the unreacted specimens. The micro-CT scans indicate a modest tortuosity decrease from 2.00 to 1.85 when calcite is dissolved, but this change in tortuosity results from the opening of new flow paths as the dissolution of discrete grains opened new flow paths and created shortcuts, not from changes to the sinuosity of existing pathways. We suggest that the marked discrepancy in the effect of calcite dissolution on permeability between our experimental data and standard models arises because of the very different way in which the porosity is increased (new pathways rather than inflation). While our results cast doubt on the general applicability of standard models for porosity-permeability relationships for situations in which porosity changes by grain-specific reactions, it is encouraging that pore scale modelling is able to reproduce the experimental relationships.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhDT.......204K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhDT.......204K"><span>Nonlinear interfacial stability of core-annular film flows in the presence of surfactants</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kas-Danouche, Said A.</p> <p></p> <p>This work is an analytical and computational study of the nonlinear interfacial instabilities found in core-annular flows in the presence of surfactants. Core-annular flows arise when two immiscible fluids (for example water and oil) are caused to flow in a pipe under the action of an axial pressure gradient. In one typical type of flow regime, the fluids arrange themselves so that the less viscous (e.g. water) lies in the region of high shear near the pipe wall, with the more viscous fluid occupying the core region. Technologically, this arrangement provides an advantage since the highly viscous fluid is lubricated by the less viscous annulus and for a given pressure gradient the core-fluid flux can be greatly increased. The stability of these flows is of fundamental scientific and practical importance. The sharp interface between the two phases can become unstable by several physical mechanisms and one such mechanism of practical importance is surface tension. In this work we incorporate into our model the effects of insoluble surfactants on the instability. The full problem is derived with particular emphasis paid to the surfactant transport equation which is novel. We then carry out an asymptotic solution of the problem when the annular layer is thin compared to the core-fluid radius and for waves which are of the order of the pipe radius (that is long compared to the annular layer thickness); these scales are in accord with both linear theory as well as experimental observations. The result of the matched asymptotic analysis is a system of coupled nonlinear partial differential equations for the interfacial amplitude and the surfactant concentration on the interface. In the absence of surfactants, the system reduces to the Kuramoto-Sivashinsky equation which has been extensively studied as a paradigm for one-dimensional turbulence in dissipative systems. The surfactant modifies the flow by inducing Marangoni forces along the interface which in turn modify both the velocities and interfacial amplitudes. There are two parameters present in the nonlinear system, the length of the system and a surface Peclet number which measures the diffusion of surfactant on the interface. In order to gain an understanding of the dynamics, we carry out extensive computations using accurate and stable numerical methods capable of following the solution for long times. We map out the dynamics by numerically solving initial value problems on spatially periodic domains where the length of the system is the bifurcation parameter, keeping the Peclet number fixed and equal to one. We find that surfactant acts to suppress chaotic behavior found in its absence for extensive ranges of the bifurcation parameter. The new flow consists of successive windows (in parameter space) of steady-state traveling waves separated by time-periodic attractors. As the length of the system increases a self-similar structure has been found to govern the shapes of the traveling waves as we move from a given window to a lower one. This is elucidated analytically and numerically.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.9268M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.9268M"><span>Association of gas hydrate formation in fluid discharges with anomalous hydrochemical profiles</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matveeva, T.</p> <p>2009-04-01</p> <p>Numerous investigations worldwide have shown that active underwater fluid discharge produces specific structures on the seafloor such as submarine seepages, vents, pockmarks, and collapse depressions. Intensive fluxes of fluids, especially of those containing hydrocarbon gases, result in specific geochemical and physical conditions favorable for gas hydrate (GH) formation. GH accumulations associated with fluid discharge are usually controlled by fluid conduits such as mud volcanoes, diapirs or faults. During last decade, subaqueous GHs become the subject of the fuel in the nearest future. However, the expediency of their commercial development can be proved solely by revealing conditions and mechanisms of GH formation. Kinetic of GH growth (although it is incompletely understood) is one of the important parameters controlling their formation among with gas solubility, pressure, temperature, gas quantity and others. Original large dataset on hydrate-related interstitial fluids obtained from different fluid discharge areas at the Sea of Okhotsk, Black Sea, Gulf of Cadiz, Lake Baikal (Eastern Siberia) allow to suggest close relation of the subaqueous GH formation process to anomalous hydrochemical profiles. We have studied the chemical and isotopic composition of interstitial fluids from GH-bearing and GH-free sediments obtained at different GH accumulations. Most attention was paid to possible influence of the interstitial fluid chemistry on the kinetic of GH formation in a porous media. The influence of salts on methane solubility within hydrate stability zones was considered by Handa (1990), Zatsepina & Buffet (1998), and later by Davie et al. (2004) from a theoretical point of view. Our idea is based on the experimentally proved fact that fugacity coefficient of methane dissolved in saline gas-saturated water which is in equilibrium with hydrates, is higher than that in more fresh water though the solubility is lower. Therefore, if a gradient of water salinity exist under conditions of hydrate stability, diffusion of methane induces hydrate formation by segregation on the outside a boundary fresher/saline water. Geochemical analysis of the interstitial fluids was used to define the mechanisms of GH accumulation and spatial distribution pattern of GHs in sediments from gas seeps abundant off NE Sakhaline Island (Sea of Okhotsk) (Matveeva et al., 2005; Mazurenko et al., submitted). A model of the ascending fluid discharge along one of the seeps named CHAOS was made based on the measured chlorinity (salinity function) of the pore waters and calculated chlorinity gradients. The chloride ion distributionprofiles with depth at the CHAOS site represent alike increasing and decreasing trends both in hydrate-bearing and hydrate-free cores. The model testifies an upward water infiltration of more saline water in vicinity of coring stations recovered GHs and relatively desalinated water mostly around those hydrate-free. It was established that GH formation at the CHAOS site is focused at the locations of intensive ascending flow of water enriched by salts that is probably function of gas solubility in water in the equilibrium with hydrate supposing that the feature is responsible for the hydrate formation just at the locations of the saline water up flows (other conditions being equal). Another case study supporting direct relation of GH formation with anomalous fluids and possible GH formation just on the interface of water flows with different salinity (defining chemical potentials of the water) is fresh-water GH accumulation at the Malenkiy fluid vent in the southern basin of Lake Baikal (Matveeva et al., 2003). The GH accumulation characterizes by heterogeneity in the spatial distribution of GH within a very small vent area. The spatial distribution of the GH-bearing and gas-saturated sediments suggests that several small fluid vents exist within the Malenkiy structure. Based on coring results, the size of these vents should not exceed a few meters. Interstitial water chemistry data indicates that water discharged within the Malenkiy vent is enriched with salts, especially Ca, Cl, and SO4 ions. The ascending water delivering gas into the GH stability zone is thought to be the main GH-forming fluid. Geochemical data suggest that the GH in the subsurface sediments of Lake Baikal originated from a deep source of water with anomalous composition assumed to be derived from buried paleolakes. As a whole, the GH accumulation corresponds to the area of the Malenkiy structure and is represented by several small scale GH occurrences coincident with local fluid discharge manifestations. The data obtained may serve as useful tool for development of geological and hydrogeochemical models of separate GH accumulations forming in the fluid discharge areas. The models on may also serve as a base for the gas inventory of the GH accumulations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1329316','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1329316"><span>Split radiator design for heat rejection optimization for a waste heat recovery system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ernst, Timothy C.; Nelson, Christopher R.</p> <p>2016-10-18</p> <p>A cooling system provides improved heat recovery by providing a split core radiator for both engine cooling and condenser cooling for a Rankine cycle (RC). The cooling system includes a radiator having a first cooling core portion and a second cooling core portion. An engine cooling loop is fluidly connected the second cooling core portion. A condenser of an RC has a cooling loop fluidly connected to the first cooling core portion. A valve is provided between the engine cooling loop and the condenser cooling loop adjustably control the flow of coolant in the condenser cooling loop into the engine cooling loop. The cooling system includes a controller communicatively coupled to the valve and adapted to determine a load requirement for the internal combustion engine and adjust the valve in accordance with the engine load requirement.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23486061','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23486061"><span>Water and hydrogen are immiscible in Earth's mantle.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bali, Enikő; Audétat, Andreas; Keppler, Hans</p> <p>2013-03-14</p> <p>In the deep, chemically reducing parts of Earth's mantle, hydrous fluids contain significant amounts of molecular hydrogen (H2). Thermodynamic models of fluids in Earth's mantle so far have always assumed that molecular hydrogen and water are completely miscible. Here we show experimental evidence that water and hydrogen can coexist as two separate, immiscible phases. Immiscibility between water and hydrogen may be the cause of the formation of enigmatic, ultra-reducing domains in the mantle that contain moissanite (SiC) and other phases indicative of extremely reducing conditions. Moreover, the immiscibility between water and hydrogen may provide a mechanism for the rapid oxidation of Earth's upper mantle immediately following core formation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJGMM..1450163P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJGMM..1450163P"><span>Effect of elastic constants of liquid crystals in their electro-optical properties</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parang, Z.; Ghaffary, T.; Gharahbeigi, M. M.</p> <p></p> <p>Recently following the success of the density functional theory (DFT) in obtaining the structure and thermodynamics of homogeneous and inhomogeneous classical systems such as simple fluids, dipolar fluid and binary hard spheres, this theory was also applied to obtain the density profile of a molecular fluid in between hard planar walls by Kalpaxis and Rickayzen. In the theory of molecular fluids, the direct correlation function (DCF) can be used to calculate the equation of state, free energy, phase transition, elastic constants, etc. It is well known that the hard core molecular models play an important role in understanding complex liquids such as liquid crystals. In this paper, a classical fluid of nonspherical molecules is studied. The required homogeneous (DCF) is obtained by solving Orenstein-Zernike (OZ) integral equation numerically. Some of the molecules in the liquid crystals have a sphere shape and this kind of molecular fluid is considered here. The DCF sphere of the molecular fluid is calculated and it will be shown that the results are in good agreement with the pervious works and the results of computer simulation. Finally the electro-optical properties of ellipsoid liquid crystal using DCF of these molecules are calculated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H11E..02M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H11E..02M"><span>4D XMT of Reaction in Carbonates: Reactive Transport Dynamics at Multiples Scales</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menke, H. P.; Reynolds, C. A.; Andrew, M. G.; Nunes, J. P. P.; Bijeljic, B.; Blunt, M. J.</p> <p>2016-12-01</p> <p>Upscaling pore scale rock-fluid interaction processes for predictive modelling poses a challenge to underground carbon storage. We have completed experiments and flow modelling to investigate the impact of pore-space heterogeneity and scale on the dissolution of two limestones at both the mm and cm scales. Two samples were reacted with reservoir condition CO2-saturated brine at both scales and scanned dynamically as dissolution took place. First, 1-cm long 4-mm diameter micro cores were scanned during reactive flow at a 4-μm resolution between 4 and 40 times using 4D X-ray micro-tomography over the course of 1.5 hours using a laboratory μ-CT. Second, 3.8-cm diameter, 8-cm long macro cores were reacted at the same conditions inside a reservoir condition flow rig and imaged using a medical CT scanner. Each sample was imaged 10 times over the course of 1.5 hours at a 250 x 250 x 500-μm resolution. The reacted macro cores were then scanned inside a μ-CT at a 27-μm resolution to assess the alteration in pore-scale reaction-induced heterogeneity. It was found that both limestones showed channel formation at the pore-scale and progressive high porosity pathway dissolution at the core-scale with the more heterogeneous rock having dissolution progressing along direction of flow more quickly. Additionally, upon analysis of the high-resolution macro core images it was found that the dissolution pathways contained a distinct microstructure that was not visible at the resolution of the medical CT, where the reactive fluid had not completely dissolved the internal pore-structure. Flow was modelled in connected pathways, the flow streamlines were traced and streamline density for each voxel was calculated. It was found that the streamline density was highest in the most well-connected pathways and that density increased with increasing heterogeneity as the number of connected pathways decreased and flow was consolidated along fewer pathways. This work represents the first study of scale dependency using reservoir condition 4D X-ray tomography and provides insight into the mechanisms that control local reaction rates at multiple scales.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130013614','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130013614"><span>Preliminary Results on Lunar Interior Properties from the GRAIL Mission</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, James G.; Konopliv, Alexander S.; Asmar, Sami W.; Lemoine, H. Jay; Melosh, H. Jay; Neumann, Gregory A.; Phillips, Roger J.; Smith, David E.; Solomon, Sean C.; Watkins, Michael M.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20130013614'); toggleEditAbsImage('author_20130013614_show'); toggleEditAbsImage('author_20130013614_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20130013614_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20130013614_hide"></p> <p>2013-01-01</p> <p>The Gravity Recovery and Interior Laboratory (GRAIL) mission has provided lunar gravity with unprecedented accuracy and resolution. GRAIL has produced a high-resolution map of the lunar gravity field while also determining tidal response. We present the latest gravity field solution and its preliminary implications for the Moon's interior structure, exploring properties such as the mean density, moment of inertia of the solid Moon, and tidal potential Love number k2. Lunar structure includes a thin crust, a deep mantle, a fluid core, and a suspected solid inner core. An accurate Love number mainly improves knowledge of the fluid core and deep mantle. In the future GRAIL will search for evidence of tidal dissipation and a solid inner core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.P32A..02T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.P32A..02T"><span>Keeping Enceladus Warm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Travis, B. J.; Schubert, G.</p> <p>2012-12-01</p> <p>Despite its small size, Enceladus emits considerable heat, especially at its south pole, even long after simple thermal models predict it should be frozen. A number of energy mechanisms have been proposed as responsible for this heating, such as TDH (tidal dissipative heating), and convection and shearing in the ice shell, but why energy outflow is primarily at the south pole is still debated. It is not known if TDH has operated continuously at Enceladus. Crater relaxation simulations suggest considerable heat flow has occurred over long stretches of its history. One process missing from previous models is fluid flow, both in an ocean layer and in the silicate core. The simulations described here are part of a study to estimate the impact of hydrothermal flow and to explore under what conditions, and for how long, an ocean layer could persist on Enceladus, with or without TDH. Our model geometry is 2-D spherical (radius and latitude) for most simulations, with one 3-D spherical simulation. We assume a silicate core of about 160 km radius, overlain by an H2O layer out to 250 km radius. Ice shell thickness is initially 15 km. Flow in an ocean layer is represented by a simplified Navier-Stokes model, and porous flow occurs in the core. Surface temperature distribution follows observed values. Radiogenic heating produces about 0.3 GW in the model. A simple TDH model is active in some simulations. Salts and/or NH3 may be present in the interior of Enceladus, and would strongly depress freezing; our model uses a low eutectic salt as an analog. The ice shell's thickness is not required to remain fixed, but can change dynamically, in response to local thermodynamics. Initial core temperature and permeability are unknowns. Initial core temperature is varied over several hundred oC, and permeability is varied over 1-100 millidarcies. In our simulations, typically, a flow field develops characterized by sinking flow at the equator and rising plumes at the poles. A broad thickening of ice in the equatorial region occurs, so much so that flow is gradually restricted to the polar regions, with the south pole flow stronger than at the northern pole. A feedback develops; cooler, sinking flow at the equator results in thickening of the ice there which in turn tends to isolate flow to the deeper ocean plus core region at the poles. The rate at which this pattern develops depends on the presence or absence of TDH. Except at the surface, a nearly cylindrical region from north to south through the model remains fluid. The presence of salt and/or NH3 allows liquid conditions and flow even as the ocean temperature falls well below 0 oC. At higher initial core temperatures, boiling occurs deep in the core because of the low overburden pressure. An approximately 70 km thick difference in ice thickness can develop between equator and poles. However, due to the low gravity of Enceladus, this would give rise to a buoyant pressure difference of only about 5 bars, which is less than shear strength measurements in ice. The core slowly cools, and eventually the ocean may freeze completely without TDH, but that can take on the order of several hundred million years or more. If episodes of strong TDH occurred on that time scale or shorter, a polar ocean might then persist indefinitely.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMDI32A..08Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMDI32A..08Y"><span>Sensitivity of the Geomagnetic Octupole to a Stably Stratified Layer in the Earth's Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, C.; Stanley, S.</p> <p>2017-12-01</p> <p>The presence of a stably stratified layer at the top of the core has long been proposed for Earth, based on evidence from seismology and geomagnetic secular variation. Geodynamo modeling offers a unique window to inspect the properties and dynamics in Earth's core. For example, numerical simulations have shown that magnetic field morphology is sensitive to the presence of stably stratified layers in a planet's core. Here we use the mMoSST numerical dynamo model to investigate the effects of a thin stably stratified layer at the top of the fluid outer core in Earth on the resulting large-scale geomagnetic field morphology. We find that the existence of a stable layer has significant influence on the octupolar component of the magnetic field in our models, whereas the quadrupole doesn't show an obvious trend. This suggests that observations of the geomagnetic field can be applied to provide information of the properties of this plausible stable layer, such as how thick and how stable this layer could be. Furthermore, we have examined whether the dominant thermal signature from mantle tomography at the core-mantle boundary (CMB) (a degree & order 2 spherical harmonic) can influence our results. We found that this heat flux pattern at the CMB has no outstanding effects on the quadrupole and octupole magnetic field components. Our studies suggest that if there is a stably stratified layer at the top of the Earth's core, it must be limited in terms of stability and thickness, in order to be compatible with the observed paleomagnetic record.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA00974.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA00974.html"><span>Schematic of Mars Interior</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1997-10-14</p> <p>The interior of Mars is simply modeled as a core and mantle with a thin crust, similar to Earth. Mars' size and total mass have been determined by previous missions. Given four parameters, the core size and mass, and mantle size and mass can be determined. The combination of Pathfinder Doppler data with earlier data from the Viking landers has determined a third parameter, the moment of inertia, through measurement of Mars' precession rate. A fourth measurement is needed to complete the interior model. This may be achieved through future Doppler tracking of Pathfinder, since the presence of a fluid core may be detectable through its effect on Mars' nutation. The determination of the moment of inertia is a significant constraint on possible models for Mars' interior. If the core is as dense as possible (i.e. completely iron) and the mantle is similar to Earth's (or similar to the SNC meteorites thought to originate on Mars) then the minimum core radius is about 1300 km. If the core is made of less-dense material (i.e. a mixture of iron and sulfur) then the core radius is probably no more than 2000 km. Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA00974</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1236338-stimuli-responsive-rheoreversible-hydraulic-fracturing-fluids-enhanced-geothermal-energy-production-part-ii','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1236338-stimuli-responsive-rheoreversible-hydraulic-fracturing-fluids-enhanced-geothermal-energy-production-part-ii"><span>Stimuli Responsive/Rheoreversible Hydraulic Fracturing Fluids for Enhanced Geothermal Energy Production (Part II)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bonneville, Alain; Jung, Hun Bok; Shao, Hongbo</p> <p></p> <p>We have used an environmentally friendly and recyclable hydraulic fracturing fluid - diluted aqueous solutions of polyallylamine or PAA – for reservoir stimulation in Enhanced Geothermal System (EGS). This fluid undergoes a controlled and large volume expansion with a simultaneous increase in viscosity triggered by CO2 at EGS temperatures. We are presenting here the results of laboratory-scale hydraulic fracturing experiment using the fluid on small cylindrical rock cores (1.59 cm in diameter and 5.08 cm in length) from the Coso geothermal field in California. Rock samples consisted of Mesozoic diorite metamorphosed to greenschist facies. The experiments were conducted on 5more » samples for realistic ranges of pressures (up to 275 bar) and temperatures (up to 210 °C) for both the rock samples and the injected fluid. After fracturing, cores were subjected to a CO2 leakage test, injection of KI solution, and X-ray microtomography (XMT) scanning to examine the formation and distribution of fractures. The design and conduct of these experiments will be presented and discussed in details. Based on the obtained XMT images, Computational Fluid Dynamics (CFD) simulations were then performed to visualize hydraulic fractures and compute the bulk permeability. OpenFOAM (OpenCFD Ltd., Reading, UK), was used to solve the steady state simulation. The flow predictions, based upon the laminar, 3-D, incompressible Navier-Stokes equations for fluid mass and momentum, show the remarkable stimulation of the permeability in the core samples and demonstrate the efficiency of such a CO2 triggered fluid in EGS.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21371197-advanced-tokamak-research-integrated-modeling-jt-upgrade','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21371197-advanced-tokamak-research-integrated-modeling-jt-upgrade"><span>Advanced tokamak research with integrated modeling in JT-60 Upgrade</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hayashi, N.</p> <p>2010-05-15</p> <p>Researches on advanced tokamak (AT) have progressed with integrated modeling in JT-60 Upgrade [N. Oyama et al., Nucl. Fusion 49, 104007 (2009)]. Based on JT-60U experimental analyses and first principle simulations, new models were developed and integrated into core, rotation, edge/pedestal, and scrape-off-layer (SOL)/divertor codes. The integrated models clarified complex and autonomous features in AT. An integrated core model was implemented to take account of an anomalous radial transport of alpha particles caused by Alfven eigenmodes. It showed the reduction in the fusion gain by the anomalous radial transport and further escape of alpha particles. Integrated rotation model showed mechanismsmore » of rotation driven by the magnetic-field-ripple loss of fast ions and the charge separation due to fast-ion drift. An inward pinch model of high-Z impurity due to the atomic process was developed and indicated that the pinch velocity increases with the toroidal rotation. Integrated edge/pedestal model clarified causes of collisionality dependence of energy loss due to the edge localized mode and the enhancement of energy loss by steepening a core pressure gradient just inside the pedestal top. An ideal magnetohydrodynamics stability code was developed to take account of toroidal rotation and clarified a destabilizing effect of rotation on the pedestal. Integrated SOL/divertor model clarified a mechanism of X-point multifaceted asymmetric radiation from edge. A model of the SOL flow driven by core particle orbits which partially enter the SOL was developed by introducing the ion-orbit-induced flow to fluid equations.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DMP.T3008O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DMP.T3008O"><span>Polaron Thermodynamics of Spin-Imbalanced Quasi-Two-Dimensional Fermi Gases</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ong, Willie; Cheng, Chingyun; Arakelyan, Ilya; Thomas, John</p> <p>2015-05-01</p> <p>We present the first spatial profile measurements for spin-imbalanced mixtures of atomic 6Li fermions in a quasi-2D geometry with tunable strong interactions. The observed minority and majority profiles are not correctly predicted by BCS theory for a true 2D system, but are reasonably well fit by a 2D-polaron model of the free energy. Density difference profiles reveal a flat center with two peaks at the edges, consistent with a fully paired core of the corresponding 2D density profiles. These features are more prominent for higher interaction strengths. Not predicted by the polaron model is an observed transition from a spin-imbalanced normal fluid phase to a spin-balanced central core above a critical imbalance. Supported by ARO, DOE, AFOSR, NSF.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1947b0017M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1947b0017M"><span>Multi-dimensional simulations of core-collapse supernova explosions with CHIMERA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Messer, O. E. B.; Harris, J. A.; Hix, W. R.; Lentz, E. J.; Bruenn, S. W.; Mezzacappa, A.</p> <p>2018-04-01</p> <p>Unraveling the core-collapse supernova (CCSN) mechanism is a problem that remains essentially unsolved despite more than four decades of effort. Spherically symmetric models with otherwise high physical fidelity generally fail to produce explosions, and it is widely accepted that CCSNe are inherently multi-dimensional. Progress in realistic modeling has occurred recently through the availability of petascale platforms and the increasing sophistication of supernova codes. We will discuss our most recent work on understanding neutrino-driven CCSN explosions employing multi-dimensional neutrino-radiation hydrodynamics simulations with the Chimera code. We discuss the inputs and resulting outputs from these simulations, the role of neutrino radiation transport, and the importance of multi-dimensional fluid flows in shaping the explosions. We also highlight the production of 48Ca in long-running Chimera simulations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998CoTPh..29..463C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998CoTPh..29..463C"><span>Velocity Profiles of Slow Blood Flow in a Narrow Tube</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Jinyu; Huang, Zuqia; Zhuang, Fengyuan; Zhang, Hui</p> <p>1998-04-01</p> <p>A fractal model is introduced into the slow blood motion. When blood flows slowly in a narrow tube, red cell aggregation results in the formation of an approximately cylindrical core of red cells. By introducing the fractal model and using the power law relation between area fraction φ and distance from tube axis ρ, rigorous velocity profiles of the fluid in and outside the aggregated core and of the core itself are obtained analytically for different fractal dimensions. It shows a blunted velocity distribution for a relatively large fractal dimension (D ˜ 2), which can be observed in normal blood; a pathological velocity profile for moderate dimension (D = 1), which is similar to the Segre-Silberberg effect; and a parabolic profile for negligible red cell concentration (D = 0), which likes in the Poiseuille flow. The project supported by the National Basic Research Project "Nonlinear Science", National Natural Science Foundation of China and the State Education Commission through the Foundation of Doctoral Training</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PEPI..276...60K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PEPI..276...60K"><span>Global conservation model for a mushy region over a moving substrate</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kyselica, J.; Šimkanin, J.</p> <p>2018-03-01</p> <p>We study solidification over a cool substrate moving with a relative velocity with respect to the rest of the fluid. A mathematical model based on global conservation of solute is presented. The explicit solutions of the governing equations are found and analysed via the asymptotic methods. The assessment of how the boundary-layer flow influences the physical characteristics of the mushy region is given, together with the discussion of a possible connection with the solidification at the inner core boundary.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMMR41B0406G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMMR41B0406G"><span>Changes in Ultrasonic Velocity from Fluid Substitution, Calculated with Laboratory Methods, Digital Rock Physics, and Biot Theory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goldfarb, E. J.; Ikeda, K.; Tisato, N.</p> <p>2017-12-01</p> <p>Seismic and ultrasonic velocities of rocks are function of several variables including fluid saturation and type. Understanding the effect of each variable on elastic waves can be valuable when using seismic methods for subsurface modeling. Fluid type and saturation are of specific interest to volcanology, water, and hydrocarbon exploration. Laboratory testing is often employed to understand the effects of fluids on elastic waves. However, laboratory testing is expensive and time consuming. It normally requires cutting rare samples into regular shapes. Fluid injection can also destroy specimens as removing the fluid after testing can prove difficult. Another option is theoretical modeling, which can be used to predict the effect of fluids on elastic properties, but it is often inaccurate. Alternatively, digital rock physics (DRP) can be used to investigate the effect of fluid substitution. DRP has the benefit of being non invasive, as it does not require regular sample shapes or fluid injection. Here, we compare the three methods for dry and saturated Berea sandstone to test the reliability of DRP. First, ultrasonic velocities were obtained from laboratory testing. Second, for comparison, we used a purely theoretical approach - i.e., Hashin-Shtrikman and Biot theory - to estimate the wave speeds at dry and wet conditions. Third, we used DRP. The dry sample was scanned with micro Computed Tomography (µCT), and a three dimensional (3D) array was recorded. We employed a segmentation-less method to convert each 3D array value to density, porosity, elastic moduli, and wave speeds. Wave propagation was simulated numerically at similar frequency as the laboratory. To simulate fluid substitution, we numerically substituted air values for water and repeated the simulation. The results from DRP yielded similar velocities to the laboratory, and accurately predicted the velocity change from fluid substitution. Theoretical modeling could not accurately predict velocity, and under-predicted the velocity change from fluid substitution. The mathematical approach proved to be a poor comparison for the laboratory measurement. DRP proved to be effective, and could be used in future with drill cuttings, perhaps to limit the use of expensive cores. DRP could also limit the requirement for physically testing fluid substitution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.207..228W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.207..228W"><span>Decadal variability in core surface flows deduced from geomagnetic observatory monthly means</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whaler, K. A.; Olsen, N.; Finlay, C. C.</p> <p>2016-10-01</p> <p>Monthly means of the magnetic field measurements at ground observatories are a key data source for studying temporal changes of the core magnetic field. However, when they are calculated in the usual way, contributions of external (magnetospheric and ionospheric) origin may remain, which make them less favourable for studying the field generated by dynamo action in the core. We remove external field predictions, including a new way of characterizing the magnetospheric ring current, from the data and then calculate revised monthly means using robust methods. The geomagnetic secular variation (SV) is calculated as the first annual differences of these monthly means, which also removes the static crustal field. SV time-series based on revised monthly means are much less scattered than those calculated from ordinary monthly means, and their variances and correlations between components are smaller. On the annual to decadal timescale, the SV is generated primarily by advection in the fluid outer core. We demonstrate the utility of the revised monthly means by calculating models of the core surface advective flow between 1997 and 2013 directly from the SV data. One set of models assumes flow that is constant over three months; such models exhibit large and rapid temporal variations. For models of this type, less complex flows achieve the same fit to the SV derived from revised monthly means than those from ordinary monthly means. However, those obtained from ordinary monthly means are able to follow excursions in SV that are likely to be external field contamination rather than core signals. Having established that we can find models that fit the data adequately, we then assess how much temporal variability is required. Previous studies have suggested that the flow is consistent with torsional oscillations (TO), solid body-like oscillations of fluid on concentric cylinders with axes aligned along the Earth's rotation axis. TO have been proposed to explain decadal timescale changes in the length-of-day. We invert for flow models where the only temporal changes are consistent with TO, but such models have an unacceptably large data misfit. However, if we relax the TO constraint to allow a little more temporal variability, we can fit the data as well as with flows assumed constant over three months, demonstrating that rapid SV changes can be reproduced by rather small flow changes. Although the flow itself changes slowly, its time derivative can be locally (temporally and spatially) large, in particular when and where core surface secular acceleration peaks. Spherical harmonic expansion coefficients of the flows are not well resolved, and many of them are strongly correlated. Averaging functions, a measure of our ability to determine the flow at a given location from the data distribution available, are poor approximations to the ideal, even when centred on points of the core surface below areas of high observatory density. Both resolution and averaging functions are noticeably worse for the toroidal flow component, which dominates the flow, than the poloidal flow component, except around the magnetic equator where averaging functions for both components are poor.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1352053','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1352053"><span>Hollow fiber apparatus and use thereof for fluids separations and heat and mass transfers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bikson, Benjamin; Etter, Stephen; Ching, Nathaniel</p> <p></p> <p>A hollow fiber fluid separation device includes a hollow fiber cartridge, comprising a plurality of hollow fiber membranes arranged around a central tubular core, a first tubesheet and a second tubesheet encapsulating respective distal ends of the hollow fiber bundle. The tubesheets have boreholes in fluid communication with bores of the hollow fiber membrane. In at least one of the tubesheets, the boreholes are formed radially and are in communication with the central tubular core. The hollow fiber fluid separation device can be utilized in liquid separation applications such as ultrafiltration and in gas separation processes such as air separation.more » The design disclosed herein is light weight and compact and is particularly advantageous at high operating temperatures when the pressure of the feed fluid introduced into the bores of hollow fibers is higher than the pressure on the shell side of the device.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21906723','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21906723"><span>Pre-shift fluid intake: effect on physiology, work and drinking during emergency wildfire fighting.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Raines, Jenni; Snow, Rodney; Petersen, Aaron; Harvey, Jack; Nichols, David; Aisbett, Brad</p> <p>2012-05-01</p> <p>Wildfire fighters are known to report to work in a hypohydrated state, which may compromise their work performance and health. To evaluate whether ingesting a bolus of fluid before the shift had any effect on firefighters' fluid consumption, core temperature, or the time they spent in high heart rate and work activity zones when fighting emergency wildfires. Thirty-two firefighters were divided into non-bolus (AD) and pre-shift drinking bolus (PS, 500 ml water) groups. Firefighters began work hypohydrated as indicated by urine colour, specific gravity and plasma osmolality (P(osm)) results. Post-shift, firefighters were classified as euhydrated according to P(osm) and hypohydrated by urinary markers. No significant differences existed between the drinking groups in pre- or post-shift hydration status, total fluid intake, activity, heart rate or core temperature. Consuming a bolus of fluid, pre-shift provided no benefit over non-consumption as both groups had consumed equivalent ad libitum volumes of fluid, 2.5 h into the shift. No benefits of bolus consumption were observed in firefighter activity, heart rate response or core temperature response across the shift in the mild weather conditions experienced. Ad libitum drinking was adequate to facilitate rehydration in firefighters upon completion of their emergency firefighting work shift. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040171523&hterms=nudging&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dnudging','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040171523&hterms=nudging&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dnudging"><span>Torque Balances on the Taylor Cylinders in the Geomagnetic Data Assimilation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuang, Weijia; Tangborn, Andrew</p> <p>2004-01-01</p> <p>In this presentation we report on our continuing effort in geomagnetic data assimilation, aiming at understanding and predicting geomagnetic secular variation on decadal time scales. In particular, we focus on the effect of the torque balances on the cylindrical surfaces in the core co-axial with the Earth's rotation axis (the Taylor cylinders) on the time evolution of assimilated solutions. We use our MoSST core dynamics,model and observed geomagnetic field at the Earth's surface derived via Comprehensive Field Model (CFM) for the geomagnetic data assimilation. In our earlier studies, a model solution is selected randomly from our numerical database. It is then assimilated with the observations such that the poloidal field possesses the same field tomography on the core-mantel boundary (CMB) continued downward from surface observations. This tomography change is assumed to be effective through out the outer core. While this approach allows rapid convergence between model solutions and the observations, it also generates sevee numerical instabilities: the delicate balance between weak fluid inertia and the magnetic torques on the Taylor cylinders are completely altered. Consequently, the assimilated solution diverges quickly (in approximately 10% of the magnetic free-decay time in the core). To improve the assimilation, we propose a partial penetration of the assimilation from the CMB: The full-scale modification at the CMB decreases linearly and vanish at an interior radius r(sub a). We shall examine from our assimilation tests possible relationships between the convergence rate of the model solutions to observations and the cut-off radius r(sub a). A better assimilation shall serve our nudging tests in near future.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUSMGP14A..02K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUSMGP14A..02K"><span>Torque Balances on the Taylor Cylinders in the Geomagnetic Data Assimilation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuang, W.; Tangborn, A.</p> <p>2004-05-01</p> <p>In this presentation we report on our continuing effort in geomagnetic data assimilation, aiming at understanding and predicting geomagnetic secular variation on decadal time scales. In particular, we focus on the effect of the torque balances on the cylindrical surfaces in the core co-axial with the Earth's rotation axis (the Taylor cylinders) on the time evolution of assimilated solutions. We use our MoSST core dynamics model and observed geomagnetic field at the Earth's surface derived via Comprehensive Field Model (CFM) for the geomagnetic data assimilation. In our earlier studies, a model solution is selected randomly from our numerical database. It is then assimilated with the observations such that the poloidal field possesses the same field tomography on the core-mantel boundary (CMB) continued downward from surface observations. This tomography change is assumed to be effective through out the outer core. While this approach allows rapid convergence between model solutions and the observations, it also generates sever numerical instabilities: the delicate balance between weak fluid inertia and the magnetic torques on the Taylor cylinders are completely altered. Consequently, the assimilated solution diverges quickly (in approximately 10% of the magnetic free-decay time in the core). To improve the assimilation, we propose a partial penetration of the assimilation from the CMB: The full-scale modification at the CMB decreases linearly and vanish at an interior radius ra. We shall examine from our assimilation tests possible relationships between the convergence rate of the model solutions to observations and the cut-off radius ra. A better assimilation shall serve our nudging tests in near future.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009CNSNS..14.2971S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009CNSNS..14.2971S"><span>Mathematical modeling of pulsatile flow of non-Newtonian fluid in stenosed arteries</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sankar, D. S.; Lee, Usik</p> <p>2009-07-01</p> <p>The pulsatile flow of blood through mild stenosed artery is studied. The effects of pulsatility, stenosis and non-Newtonian behavior of blood, treating the blood as Herschel-Bulkley fluid, are simultaneously considered. A perturbation method is used to analyze the flow. The expressions for the shear stress, velocity, flow rate, wall shear stress, longitudinal impedance and the plug core radius have been obtained. The variations of these flow quantities with different parameters of the fluid have been analyzed. It is found that, the plug core radius, pressure drop and wall shear stress increase with the increase of yield stress or the stenosis height. The velocity and the wall shear stress increase considerably with the increase in the amplitude of the pressure drop. It is clear that for a given value of stenosis height and for the increasing values of the stenosis shape parameter from 3 to 6, there is a sharp increase in the impedance of the flow and also the plots are skewed to the right-hand side. It is observed that the estimates of the increase in the longitudinal impedance increase with the increase of the axial distance or with the increase of the stenosis height. The present study also brings out the effects of asymmetric of the stenosis on the flow quantities.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFDR24002W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFDR24002W"><span>Fluid-Structure Interactions as Flow Propagates Tangentially Over a Flexible Plate with Application to Voiced Speech Production</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Westervelt, Andrea; Erath, Byron</p> <p>2013-11-01</p> <p>Voiced speech is produced by fluid-structure interactions that drive vocal fold motion. Viscous flow features influence the pressure in the gap between the vocal folds (i.e. glottis), thereby altering vocal fold dynamics and the sound that is produced. During the closing phases of the phonatory cycle, vortices form as a result of flow separation as air passes through the divergent glottis. It is hypothesized that the reduced pressure within a vortex core will alter the pressure distribution along the vocal fold surface, thereby aiding in vocal fold closure. The objective of this study is to determine the impact of intraglottal vortices on the fluid-structure interactions of voiced speech by investigating how the dynamics of a flexible plate are influenced by a vortex ring passing tangentially over it. A flexible plate, which models the medial vocal fold surface, is placed in a water-filled tank and positioned parallel to the exit of a vortex generator. The physical parameters of plate stiffness and vortex circulation are scaled with physiological values. As vortices propagate over the plate, particle image velocimetry measurements are captured to analyze the energy exchange between the fluid and flexible plate. The investigations are performed over a range of vortex formation numbers, and lateral displacements of the plate from the centerline of the vortex trajectory. Observations show plate oscillations with displacements directly correlated with the vortex core location.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S54A..05S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S54A..05S"><span>Hydro-geophysical responses to the injection of CO2 in core plugs of Berea sandstone</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, I.; Park, K. G.</p> <p>2017-12-01</p> <p>We have built a laboratory-scale core flooding system to measure the relative permeability of a core sample and the acoustic response to the CO2 saturation degree at in situ condition of pressure and temperature down to a few kilometer depths. The system consisted of an acoustic velocity core holder (AVC model from the Core Laboratories) between upstream where CO2 and H2O were injected separately and downstream where the mixed fluids came out of a core sample. Core samples with 4 cm in diameter and 5 cm in length of Berea sandstone were in turn placed in the core holder for confining and axial pressures. The flooding operations of the multiphase fluids were conducted through the sample at 40ºC in temperature and 8 MPa in backpressure. CO2 and H2O in the physical condition were injected separately into a sample at constant rate with various ratios. The two phases were mixed during flowing through the sample. The mixed fluids out of the sample were separated again by their different densities in a chamber equipped with a level gauge of the interface. From the level change of the water in the separator, we measured the volume of water coming out of the sample for each test with a constant ratio of the injection rates. Then it was possible to calculate the saturation degree of CO2 from the difference between input volume and output volume of water. The differential pressure between upstream and downstream was directly measured to calculate the relative permeability as a function of the CO2 saturation degree. We also conducted ultrasonic measurements using piezoelectric sensors on the end plugs. An electric pulse was given to a sensor on one end of sample, and then ultrasonic waves were recorded from the other end. The various ratios of injection rate of CO2 and H2O into Berea sandstone yielded a range of 0.1-0.7 in CO2 saturation degree. The relative permeability was obtained at the condition of steady-state flow for given stages from the velocity of each phase and the pressure gradient. The arrival time of P-wave became retarded and its amplitude became smaller as the degree of CO2 saturation increases. However no change was observed in S-wave in both characters. According to our results, time-lapse measurements of P-wave signals can be a monitoring tool of the subsurface migration of CO2, thus of detecting even its leakage.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872265','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872265"><span>Spiral wound extraction cartridge</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wisted, Eric E.; Lundquist, Susan H.</p> <p>1999-01-01</p> <p>A cartridge device for removing an analyte from a fluid comprises a hollow core, a sheet composite comprising a particulate-loaded porous membrane and optionally at least one reinforcing spacer sheet, the particulate being capable of binding the analyte, the sheet composite being formed into a spiral configuration about the core, wherein the sheet composite is wound around itself and wherein the windings of sheet composite are of sufficient tightness so that adjacent layers are essentially free of spaces therebetween, two end caps which are disposed over the core and the lateral ends of the spirally wound sheet composite, and means for securing the end caps to the core, the end caps also being secured to the lateral ends of the spirally wound sheet composite. A method for removing an analyte from a fluid comprises the steps of providing a spirally wound element of the invention and passing the fluid containing the analyte through the element essentially normal to a surface of the sheet composite so as to bind the analyte to the particulate of the particulate-loaded porous membrane, the method optionally including the step of eluting the bound analyte from the sheet composite.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HESS...20...39T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HESS...20...39T"><span>Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timms, W. A.; Crane, R.; Anderson, D. J.; Bouzalakos, S.; Whelan, M.; McGeeney, D.; Rahman, P. F.; Acworth, R. I.</p> <p>2016-01-01</p> <p>Evaluating the possibility of leakage through low-permeability geological strata is critically important for sustainable water supplies, the extraction of fuels from coal and other strata, and the confinement of waste within the earth. The current work demonstrates that relatively rapid and realistic vertical hydraulic conductivity (Kv) measurements of aquitard cores using accelerated gravity can constrain and compliment larger-scale assessments of hydraulic connectivity. Steady-state fluid velocity through a low-K porous sample is linearly related to accelerated gravity (g level) in a centrifuge permeameter (CP) unless consolidation or geochemical reactions occur. A CP module was custom designed to fit a standard 2 m diameter geotechnical centrifuge (550 g maximum) with a capacity for sample dimensions up to 100 mm diameter and 200 mm length, and a total stress of ˜ 2 MPa at the base of the core. Formation fluids were used as influent to limit any shrink-swell phenomena, which may alter the permeability. Kv results from CP testing of minimally disturbed cores from three sites within a clayey-silt formation varied from 10-10 to 10-7 m s-1 (number of samples, n = 18). Additional tests were focussed on the Cattle Lane (CL) site, where Kv within the 99 % confidence interval (n = 9) was 1.1 × 10<Superscript>-9</Superscript> to 2.0 × 10<Superscript>-9</Superscript> m s<Superscript>-1</Superscript>. These Kv results were very similar to an independent in situ Kv method based on pore pressure propagation though the sequence. However, there was less certainty at two other core sites due to limited and variable Kv data. Blind standard 1 g column tests underestimated Kv compared to CP and in situ Kv data, possibly due to deionised water interactions with clay, and were more time-consuming than CP tests. Our Kv results were compared with the set-up of a flow model for the region, and considered in the context of heterogeneity and preferential flow paths at site and formation scale. Reasonable assessments of leakage and solute transport through aquitards over multi-decadal timescales can be achieved by accelerated core testing together with complimentary hydrogeological monitoring, analysis, and modelling.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B12B..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B12B..03M"><span>Constraints on hydrocarbon and organic acid abundances in hydrothermal fluids at the Von Damm vent field, Mid-Cayman Rise (Invited)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDermott, J. M.; Seewald, J.; German, C. R.; Sylva, S. P.</p> <p>2013-12-01</p> <p>The generation of organic compounds in vent fluids has been of interest since the discovery of seafloor hydrothermal systems, due to implications for the sustenance of present-day microbial populations and their potential role in the origin of life on early Earth. Possible sources of organic compounds in hydrothermal systems include microbial production, thermogenic degradation of organic material, and abiotic synthesis. Abiotic organic synthesis reactions may occur during active circulation of seawater-derived fluids through the oceanic crust or within olivine-hosted fluid inclusions containing carbon-rich magmatic volatiles. H2-rich end-member fluids at the Von Damm vent field on the Mid-Cayman Rise, where fluid temperatures reach 226°C, provide an exciting opportunity to examine the extent of abiotic carbon transformations in a highly reducing system. Our results indicate multiple sources of carbon compounds in vent fluids at Von Damm. An ultramafic-influenced hydrothermal system located on the Mount Dent oceanic core complex at 2350 m depth, Von Damm vent fluids contain H2, CH4, and C2+ hydrocarbons in high abundance relative to basalt-hosted vent fields, and in similar abundance to other ultramafic-hosted systems, such as Rainbow and Lost City. The CO2 content and isotopic composition in end-member fluids are virtually identical to bottom seawater, suggesting that seawater DIC is unchanged during hydrothermal circulation of seawater-derived fluids. Accordingly, end-member CH4 that is present in slightly greater abundance than CO2 cannot be generated from reduction of aqueous CO2 during hydrothermal circulation. We postulate that CH4 and C2+ hydrocarbons that are abundantly present in Von Damm vent fluids reflect leaching of fluids from carbon- and H2-rich fluid inclusions hosted in plutonic rocks. Geochemical modeling of carbon speciation in the Von Damm fluids suggests that the relative abundances of CH4, C2+ hydrocarbons, and CO2 are consistent with thermodynamic equilibrium at higher temperatures and more reducing conditions than those observed in the Von Damm vent fluids. These findings are consistent with a scenario in which n-alkanes form abiotically within a high-H2, carbon-rich olivine-hosted fluid inclusion, and are subsequently liberated and transported to the seafloor during hydrothermal alteration of the lower crustal rocks exposed at the Mount Dent oceanic core complex. Mixed fluids at Von Damm show depletions in CO2 and H2, relative to conservative mixing. Multiple S isotope measurements indicate that the H2 sink cannot be attributed to sulfate reduction. Thermodynamic constraints indicate that high-H2 conditions support the active formation of formate via reduction of dissolved CO2 during hydrothermal circulation - a process that has also been described at the Lost City vent field - and could account for the concurrent depletions in CO2 and H2. The transformation of inorganic carbon to organic compounds via two distinct pathways in modern seafloor hydrothermal vents validates theoretical and experimental conceptual models regarding processes occurring in the crust and during hydrothermal circulation, and is relevant to supporting life in vent ecosystems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22606249-molecular-dynamics-simulation-water-around-carbon-nanotubes-coarse-grained-description','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22606249-molecular-dynamics-simulation-water-around-carbon-nanotubes-coarse-grained-description"><span>Molecular dynamics simulation of water in and around carbon nanotubes: A coarse-grained description</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pantawane, Sanwardhini; Choudhury, Niharendu, E-mail: nihcho@barc.gov.in</p> <p>2016-05-23</p> <p>In the present study, we intend to investigate behaviour of water in and around hydrophobic open ended carbon nanotubes (CNTs) using a coarse-grained, core-softened model potential for water. The model potential considered here for water has recently been shown to successfully reproduce dynamic, thermodynamic and structural anomalies of water. The epitome of the study is to understand the incarceration of this coarse-grained water in a single-file carbon nanotube. In order to examine the effect of fluid-water van der Waals interaction on the structure of fluid in and around the nanotube, we have simulated three different CNT-water systems with varying degreemore » of solute-water dispersion interaction. The analyses of the radial one-particle density profiles reveal varying degree of permeation and wetting of the CNT interior depending on the degree of fluid-solute attractive van der Waals interaction. A peak in the radial density profile slightly off the nanotube axis signifies a zigzag chain of water molecule around the CNT axis. The average numbers of water molecules inside the CNT have been shown to increase with the increase in fluid-water attractive dispersion interaction.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3980840','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3980840"><span>Thermophysical and Mechanical Properties of Granite and Its Effects on Borehole Stability in High Temperature and Three-Dimensional Stress</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bao-lin, Liu; Hai-yan, Zhu; Chuan-liang, Yan; Zhi-jun, Li; Zhi-qiao, Wang</p> <p>2014-01-01</p> <p>When exploiting the deep resources, the surrounding rock readily undergoes the hole shrinkage, borehole collapse, and loss of circulation under high temperature and high pressure. A series of experiments were conducted to discuss the compressional wave velocity, triaxial strength, and permeability of granite cored from 3500 meters borehole under high temperature and three-dimensional stress. In light of the coupling of temperature, fluid, and stress, we get the thermo-fluid-solid model and governing equation. ANSYS-APDL was also used to stimulate the temperature influence on elastic modulus, Poisson ratio, uniaxial compressive strength, and permeability. In light of the results, we establish a temperature-fluid-stress model to illustrate the granite's stability. The compressional wave velocity and elastic modulus, decrease as the temperature rises, while poisson ratio and permeability of granite increase. The threshold pressure and temperature are 15 MPa and 200°C, respectively. The temperature affects the fracture pressure more than the collapse pressure, but both parameters rise with the increase of temperature. The coupling of thermo-fluid-solid, greatly impacting the borehole stability, proves to be a good method to analyze similar problems of other formations. PMID:24778592</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24778592','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24778592"><span>Thermophysical and mechanical properties of granite and its effects on borehole stability in high temperature and three-dimensional stress.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yu; Liu, Bao-lin; Zhu, Hai-yan; Yan, Chuan-liang; Li, Zhi-jun; Wang, Zhi-qiao</p> <p>2014-01-01</p> <p>When exploiting the deep resources, the surrounding rock readily undergoes the hole shrinkage, borehole collapse, and loss of circulation under high temperature and high pressure. A series of experiments were conducted to discuss the compressional wave velocity, triaxial strength, and permeability of granite cored from 3500 meters borehole under high temperature and three-dimensional stress. In light of the coupling of temperature, fluid, and stress, we get the thermo-fluid-solid model and governing equation. ANSYS-APDL was also used to stimulate the temperature influence on elastic modulus, Poisson ratio, uniaxial compressive strength, and permeability. In light of the results, we establish a temperature-fluid-stress model to illustrate the granite's stability. The compressional wave velocity and elastic modulus, decrease as the temperature rises, while poisson ratio and permeability of granite increase. The threshold pressure and temperature are 15 MPa and 200 °C, respectively. The temperature affects the fracture pressure more than the collapse pressure, but both parameters rise with the increase of temperature. The coupling of thermo-fluid-solid, greatly impacting the borehole stability, proves to be a good method to analyze similar problems of other formations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhCS.974a2015F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhCS.974a2015F"><span>Turbulent flow in a vessel agitated by side entering inclined blade turbine with different diameter using CFD simulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fathonah, N. N.; Nurtono, T.; Kusdianto; Winardi, S.</p> <p>2018-03-01</p> <p>Single phase turbulent flow in a vessel agitated by side entering inclined blade turbine has simulated using CFD. The aim of this work is to identify the hydrodynamic characteristics of a model vessel, which geometrical configuration is adopted at industrial scale. The laboratory scale model vessel is a flat bottomed cylindrical tank agitated by side entering 4-blade inclined blade turbine with impeller rotational speed N=100-400 rpm. The effect of the impeller diameter on fluid flow pattern has been investigated. The fluid flow patterns in a vessel is essentially characterized by the phenomena of macro-instabilities, i.e. the flow patterns change with large scale in space and low frequency. The intensity of fluid flow in the tank increase with the increase of impeller rotational speed from 100, 200, 300, and 400 rpm. It was accompanied by shifting the position of the core of circulation flow away from impeller discharge stream and approached the front of the tank wall. The intensity of fluid flow in the vessel increase with the increase of the impeller diameter from d=3 cm to d=4 cm.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012IJCFD..26..193D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IJCFD..26..193D"><span>A heterogeneous system based on GPU and multi-core CPU for real-time fluid and rigid body simulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>da Silva Junior, José Ricardo; Gonzalez Clua, Esteban W.; Montenegro, Anselmo; Lage, Marcos; Dreux, Marcelo de Andrade; Joselli, Mark; Pagliosa, Paulo A.; Kuryla, Christine Lucille</p> <p>2012-03-01</p> <p>Computational fluid dynamics in simulation has become an important field not only for physics and engineering areas but also for simulation, computer graphics, virtual reality and even video game development. Many efficient models have been developed over the years, but when many contact interactions must be processed, most models present difficulties or cannot achieve real-time results when executed. The advent of parallel computing has enabled the development of many strategies for accelerating the simulations. Our work proposes a new system which uses some successful algorithms already proposed, as well as a data structure organisation based on a heterogeneous architecture using CPUs and GPUs, in order to process the simulation of the interaction of fluids and rigid bodies. This successfully results in a two-way interaction between them and their surrounding objects. As far as we know, this is the first work that presents a computational collaborative environment which makes use of two different paradigms of hardware architecture for this specific kind of problem. Since our method achieves real-time results, it is suitable for virtual reality, simulation and video game fluid simulation problems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........77Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........77Y"><span>Alternating current dielectrophoresis of core-shell nanoparticles: Experiments and comparison with theory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Chungja</p> <p></p> <p>Nanoparticles are fascinating where physical and optical properties are related to size. Highly controllable synthesis methods and nanoparticle assembly are essential for highly innovative technological applications. Well-defined shaped and sized nanoparticles enable comparisons between experiments, theory and subsequent new models to explain experimentally observed phenomena. Among nanoparticles, nonhomogeneous core-shell nanoparticles (CSnp) have new properties that arise when varying the relative dimensions of the core and the shell. This CSnp structure enables various optical resonances, and engineered energy barriers, in addition to the high charge to surface ratio. Assembly of homogeneous nanoparticles into functional structures has become ubiquitous in biosensors (i.e. optical labeling), nanocoatings, and electrical circuits. Limited nonhomogenous nanoparticle assembly has only been explored. Many conventional nanoparticle assembly methods exist, but this work explores dielectrophoresis (DEP) as a new method. DEP is particle polarization via non-uniform electric fields while suspended in conductive fluids. Most prior DEP efforts involve microscale particles. Prior work on core-shell nanoparticle assemblies and separately, nanoparticle characterizations with dielectrophoresis and electrorotation, did not systematically explore particle size, dielectric properties (permittivity and electrical conductivity), shell thickness, particle concentration, medium conductivity, and frequency. This work is the first, to the best of our knowledge, to systematically examine these dielectrophoretic properties for core-shell nanoparticles. Further, we conduct a parametric fitting to traditional core-shell models. These biocompatible core-shell nanoparticles were studied to fill a knowledge gap in the DEP field. Experimental results (chapter 5) first examine medium conductivity, size and shell material dependencies of dielectrophoretic behaviors of spherical CSnp into 2D and 3D particle-assemblies. Chitosan (amino sugar) and poly-L-lysine (amino acid, PLL) CSnp shell materials were custom synthesized around a hollow (gas) core by utilizing a phospholipid micelle around a volatile fluid templating for the shell material; this approach proves to be novel and distinct from conventional core-shell models wherein a conductive core is coated with an insulative shell. Experiments were conducted within a 100 nl chamber housing 100 um wide Ti/Au quadrapole electrodes spaced 25 um apart. Frequencies from 100kHz to 80MHz at fixed local field of 5Vpp were tested with 10-5 and 10-3 S/m medium conductivities for 25 seconds. Dielectrophoretic responses of ~220 and 340(or ~400) nm chitosan or PLL CSnp were compiled as a function of medium conductivity, size and shell material. Experiments further examined shell thickness and particle concentration (chapter 6) dependencies on ~530 nm CSnp dielectrophoretic and electrorotational responses with ~30nm and ~80 nm shell thicknesses and at particle concentration count rates of 5000 +/- 500, 10000 +/- 500, and 15000 +/- 500 counts per second. Using similar experimental conditions, both dielectrophoretic and electrorotational CSnp responses were compiled versus frequency, shell thickness, and particle concentration. Knowledge gained from this study includes a unique resonance-like dielectrophoretic and electrorotational spectrum, which is significantly distinct from other cells and particles. CSnp dielectric properties were then calculated by parametrically fitting parameters to an existing core-shell model. The optimum conductivity and relative permittivity for the core and the shell are 1E-15 S/m, 1, 0.6 S/m, and 90, respectively. These properties can be exploited to rapidly assemble these unique core-shell particles for future structural color production in fabrics, vehicle, and wall painting.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5552079','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5552079"><span>Coaxial Electrospinning and Characterization of Core-Shell Structured Cellulose Nanocrystal Reinforced PMMA/PAN Composite Fibers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Chao; Li, Qingde; Ni, Xiaohui; Liu, Guoxiang; Cheng, Wanli; Han, Guangping</p> <p>2017-01-01</p> <p>A modified coaxial electrospinning process was used to prepare composite nanofibrous mats from a poly(methyl methacrylate) (PMMA) solution with the addition of different cellulose nanocrystals (CNCs) as the sheath fluid and polyacrylonitrile (PAN) solution as the core fluid. This study investigated the conductivity of the as-spun solutions that increased significantly with increasing CNCs addition, which favors forming uniform fibers. This study discussed the effect of different CNCs addition on the morphology, thermal behavior, and the multilevel structure of the coaxial electrospun PMMA + CNCs/PAN composite nanofibers. A morphology analysis of the nanofibrous mats clearly demonstrated that the CNCs facilitated the production of the composite nanofibers with a core-shell structure. The diameter of the composite nanofibers decreased and the uniformity increased with increasing CNCs concentrations in the shell fluid. The composite nanofibrous mats had the maximum thermal decomposition temperature that was substantially higher than electrospun pure PMMA, PAN, as well as the core-shell PMMA/PAN nanocomposite. The BET (Brunauer, Emmett and Teller) formula results showed that the specific surface area of the CNCs reinforced core-shell composite significantly increased with increasing CNCs content. The specific surface area of the composite with 20% CNCs loading rose to 9.62 m2/g from 3.76 m2/g for the control. A dense porous structure was formed on the surface of the electrospun core-shell fibers. PMID:28772933</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175596','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175596"><span>Method for automatically scramming a nuclear reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ougouag, Abderrafi M.; Schultz, Richard R.; Terry, William K.</p> <p>2005-12-27</p> <p>An automatically scramming nuclear reactor system. One embodiment comprises a core having a coolant inlet end and a coolant outlet end. A cooling system operatively associated with the core provides coolant to the coolant inlet end and removes heated coolant from the coolant outlet end, thus maintaining a pressure differential therebetween during a normal operating condition of the nuclear reactor system. A guide tube is positioned within the core with a first end of the guide tube in fluid communication with the coolant inlet end of the core, and a second end of the guide tube in fluid communication with the coolant outlet end of the core. A control element is positioned within the guide tube and is movable therein between upper and lower positions, and automatically falls under the action of gravity to the lower position when the pressure differential drops below a safe pressure differential.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H23D1009M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H23D1009M"><span>Geologic Storage at the Basin Scale: Region-Based Basin Modeling, Powder River Basin (PRB), NE Wyoming and SE Montana</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melick, J. J.; Gardner, M. H.</p> <p>2008-12-01</p> <p>Carbon capture and storage from the over 2000 power plants is estimated at 3-5 GT/yr, which requires large- scale geologic storage of greenhouse gasses in sedimentary basins. Unfortunately, determination of basin scale storage capacity is currently based on oversimplified geologic models that are difficult to validate. Simplification involves reducing the number of geologic parameters incorporated into the model, modeling with large grid cells, and treatment of subsurface reservoirs as homogeneous media. The latter problem reflects the focus of current models on fluid and/or fluid-rock interactions rather than fluid movement and migration pathways. For example, homogeneous models over emphasize fluid behavior, like the buoyancy of super-critical CO2, and hence overestimate leakage rates. Fluid mixing and fluid-rock interactions cannot be assessed with models that only investigate these reactions at a human time scale. Preliminary and conservative estimates of the total pore volume for the PRB suggest 200 GT of supercritical CO2 can be stored in this typical onshore sedimentary basin. The connected pore volume (CPV) however is not included in this estimate. Geological characterization of the CPV relates subsurface storage units to the most prolific reservoir classes (RCs). The CPV, number of well penetrations, supercritical storage area, and potential leakage pathways characterize each RC. Within each RC, a hierarchy of stratigraphic cycles is populated with stationary sedimentation regions that control rock property distributions by correlating environment of deposition (EOD) to CPV. The degree to which CPV varies between RCs depends on the geology and attendant heterogeneity retained in the fluid flow model. Region-based modeling of the PRB incorporates 28000 wells correlated across a 70,000 Km2 area, 2 km thick on average. Within this basin, five of the most productive RCs were identified from production history and placed in a fourfold stratigraphic framework (second- through fourth-order cycles). Within the small- scale 4th-order sequences (30-150-m thick, 16 total), sedimentation regions, each corresponding to an EOD, are defined by thickness, lithology and core-calibrated well-log patterns. This talk illustrates the workflow by focusing on one of the 16 layers in the basin-scale model. Isopach maps from this sample layer conform to depositional patterns confirmed through definition of five core-calibrated, well-log defined sedimentation regions. Lithology distributions also conform to thickness trends in nearshore deltas, but not in offshore regions, where sand-rich and sheet-like, but thin-bedded sandstones are flanked by mud-rich intervals of equivalent thickness. These maps represent sedimentation patterns confined by basal erosional sequence boundary and basin-wide bentonite, yet containing up to seven high-frequency sequence boundaries. To illustrate over simplification problems in this same layer, a 14000 km2 sample area is 600 km3 and using standard averaging methods, which are considered to be geologic in origin, the CPV is 16 km3. However, averaging increases connectivity with high CPV more uniformly distributed; significantly, the key mud belt region separating nearshore from offshore sandstones is not represented. Region-based modeling of this layer yields 13 km3 (110 Bbl). Furthermore, significant vertical leakage may exist from the 20000 well penetrations and faults and fractures along the western basin margin. This example illustrates the importance of accurately characterizing heterogeneity and distributing CPV using sedimentation regions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24387380','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24387380"><span>Effect of attractive interactions on the water-like anomalies of a core-softened model potential.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pant, Shashank; Gera, Tarun; Choudhury, Niharendu</p> <p>2013-12-28</p> <p>It is now well established that water-like anomalies can be reproduced by a spherically symmetric potential with two length scales, popularly known as core-softened potential. In the present study we aim to investigate the effect of attractive interactions among the particles in a model fluid interacting with core-softened potential on the existence and location of various water-like anomalies in the temperature-pressure plane. We employ extensive molecular dynamic simulations to study anomalous nature of various order parameters and properties under isothermal compression. Order map analyses have also been done for all the potentials. We observe that all the systems with varying depth of attractive wells show structural, dynamic, and thermodynamic anomalies. As many of the previous studies involving model water and a class of core softened potentials have concluded that the structural anomaly region encloses the diffusion anomaly region, which in turn, encloses the density anomaly region, the same pattern has also been observed in the present study for the systems with less depth of attractive well. For the systems with deeper attractive well, we observe that the diffusion anomaly region shifts toward higher densities and is not always enclosed by the structural anomaly region. Also, density anomaly region is not completely enclosed by diffusion anomaly region in this case.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28085851','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28085851"><span>All-fiber magnetic field sensor based on tapered thin-core fiber and magnetic fluid.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Junying; Qiao, Xueguang; Yang, Hangzhou; Wang, Ruohui; Rong, Qiangzhou; Lim, Kok-Sing; Ahmad, Harith</p> <p>2017-01-10</p> <p>A method for the measurement of a magnetic field by combining a tapered thin-core fiber (TTCF) and magnetic fluid is proposed and experimentally demonstrated. The modal interference effect is caused by the core mode and excited eigenmodes in the TTCF cladding. The transmission spectra of the proposed sensor are measured and theoretically analyzed at different magnetic field strengths. The results field show that the magnetic sensitivity reaches up to -0.1039 dB/Oe in the range of 40-1600 e. The proposed method possesses high sensitivity and low cost compared with other expensive methods.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22540454','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22540454"><span>Rocky core solubility in Jupiter and giant exoplanets.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilson, Hugh F; Militzer, Burkhard</p> <p>2012-03-16</p> <p>Gas giants are believed to form by the accretion of hydrogen-helium gas around an initial protocore of rock and ice. The question of whether the rocky parts of the core dissolve into the fluid H-He layers following formation has significant implications for planetary structure and evolution. Here we use ab initio calculations to study rock solubility in fluid hydrogen, choosing MgO as a representative example of planetary rocky materials, and find MgO to be highly soluble in H for temperatures in excess of approximately 10,000 K, implying the potential for significant redistribution of rocky core material in Jupiter and larger exoplanets.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GeCoA.122..324G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GeCoA.122..324G"><span>Hydrothermal mobilization of pegmatite-hosted REE and Zr at Strange Lake, Canada: A reaction path model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gysi, Alexander P.; Williams-Jones, Anthony E.</p> <p>2013-12-01</p> <p>Petrological and geochemical observations of pegmatites in the Strange Lake pluton, Canada, have been combined with numerical simulations to improve our understanding of fluid-rock interaction in peralkaline granitic systems. In particular, they have made it possible to evaluate reaction paths responsible for hydrothermal mobilization and mineralization of rare earth elements (REE) and Zr. The focus of the study was the B-Zone in the northwest of the pluton, which contains a pegmatite swarm and is the target of exploration for an economically exploitable REE deposit. Many of the pegmatites are mineralogically zoned into a border consisting of variably altered primary K-feldspar, arfvedsonite, quartz, and zirconosilicates, and a core rich in quartz, fluorite and exotic REE minerals. Textural relationships indicate that the primary silicate minerals in the pegmatites were leached and/or replaced during acidic alteration by K-, Fe- and Al-phyllosilicates, aegirine, hematite, fluorite and/or quartz, and that primary zirconosilicates (e.g., elpidite) were replaced by gittinsite and/or zircon. Reaction textures recording coupled dissolution of silicate minerals and crystallization of secondary REE-silicates indicate hydrothermal mobilization of the REE. The mobility of the light (L)REE was limited by the stability of REE-F-(CO2)-minerals (basnäsite-(Ce) and fluocerite-(Ce)), whereas zirconosilicates and secondary gadolinite-group minerals controlled the mobility of Zr and the heavy (H)REE. Hydrothermal fluorite and fluorite-fluocerite-(Ce) solid solutions are interpreted to indicate the former presence of F-bearing saline fluids in the pegmatites. Numerical simulations show that the mobilization of REE and Zr in saline HCl-HF-bearing fluids is controlled by pH, ligand activity and temperature. Mobilization of Zr is significant in both saline HF- and HCl-HF-bearing fluids at low temperature (250 °C). In contrast, the REE are mobilized by saline HCl-bearing fluids, particularly at high temperature (400 °C). The LREE are more mobile than the HREE in saline HCl-bearing fluids due to the greater stability of LREE-chloride complexes. The simulated mineralogy is consistent with the zonation observed in the pegmatites and with fluid-rock interaction at conditions that were rock-buffered in the pegmatite borders (low fluid/rock ratio; and pH > 4) and fluid-buffered in the cores (high fluid/rock ratio; pH ⩽ 2). We propose a model in which saline HCl-HF-bearing fluids created pathways during acidic alteration from the pegmatite cores outward. This led to the mobilization of REE and Zr due to progressive alteration of primary silicate minerals and increased acidity upon cooling. The key requirement for REE and Zr mobilization in peralkaline igneous intrusions is the formation of an acidic subsystem with high fluid/rock ratios that increases the overall permeability of the rocks. In these zones, the extent of late stage hydrothermal redistribution and concentration of REE and Zr depends on the buffering capacity of the rocks and the availability of fluids that may produce autometasomatic rock alteration, interact with external rock units and/or mix with fluids from other sources. b The detection limits of Yb were 1043 ppm for zircon, 380 ppm for gadolinite-group minerals and 380 ppm for REE-F-(CO2)-minerals. </ce:legend></ce:table></ce:display></ce:section> bAja et al. (1995). cMigdisov et al. (2011). dTagirov et al. (1997). eTagirov and Schott (2001). fMigdisov et al. (2009) with REE (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu). </ce:legend></ce:table></ce:display></ce:section> b Calculated using the methods of the Chermak and Rimstidt (1989), Berman and Brown (1985) and Holland (1989) with molar volume of arfvedsonite from Hawthorne (1976). cZotov et al. (1998). d GEM-Selektor v.3 database (http://gems.web.psi.ch). eMigdisov et al. (2009). </ce:legend></ce:table></ce:display></p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS21B1123H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS21B1123H"><span>Episodic Deep Fluid Expulsion at Mud Volcanoes in the Kumano Forearc Basin, SE Offshore Japan</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hammerschmidt, S.; Kopf, A.</p> <p>2014-12-01</p> <p>Compressional forces at convergent margins govern a variety of processes, most prominently earthquakes, landslides and mud volcanoes in the forearc. Although all seem related to fluid pressure changes, mud volcanoes are not only characterized by expulsion of fluids, but also fluidized mud and clasts that got ripped-up during mud ascension. They hence provide information regarding mobilization depth, diagenetic overprint, and geodynamic pathways. At the Nankai Trough subduction zone, SE offshore Japan, mud volcanism id common and supposed to be related to seismogenic processes. During MARUM Expedition SO-222 with R/V SONNE, mud volcanoes in the Kumano forearc basin were mapped, cored and sampled. By extending the Integrated Ocean Drilling Program (IODP) Kumano transect landwards, 5 new mud volcanoes were identified by multibeam mapping. Cores revealed mud breccia with semi-consolidated silt- to claystone clasts and gaseous fluid escape structures, while the hemipelagic background sediments are characterized by intercalations of turbidites, ash layers and calcareous fossils. Clasts were subject to thin-section analyses, and the cores were sampled for XRD analyses and radiocarbon dating. Clasts showed prominent deformation structures, neomorphism and pores and fractures filled with polycrystalline quartz and/or calcite cement, probably formed during deep burial and early metamorphosis. Illite crystallinity based on XRD measurements varies between 0.24 and 0.38, which implies that the material originates from the Anchizone at depths ≥ 4 km. Radiocarbon dating revealed ages between 4450 and 30300 yr cal. BP, with age reversals occurring not earlier than 17000 yr cal. BP. Radiocarbon dating beneath turbidites and ash layers found at mud volcano #9 points to an episodic occurrence of these earthquake-related features in intervals of ca. 620 yr, while the mud volcano itself remained inactive. In summary, the preliminary results suggest that the mud volcanoes are nurtured from a reservoir within the older part of the accretionary prism, but that mud volcanic activity is less frequent than major earthquakes. Future models will focus on source depth and temperature, and might elucidate the prerequisites for fluid migration and its role in seismogenesis at the Nankai Trough subduction zone.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21126666','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21126666"><span>Prevention of hypothermia by infusion of warm fluid during abdominal surgery.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Hong-xia; You, Zhi-Jian; Zhang, Hong; Li, Zhiqing</p> <p>2010-12-01</p> <p>Perioperative hypothermia can lead to a number of complications for patients after surgery. The aim of this pilot study was to evaluate the efficacy of warm fluids in maintaining normal core temperature during the intraoperative period. We studied 30 American Society of Anesthesiologists (ASA) physical status I or II adult patients who required general anesthesia for abdominal surgery. In the control group (n = 15), fluids were infused at room temperature; in the test group (n = 15), fluids were infused at 37° C. In the control group, core temperature decreased to 35.5 ± 0.3° C during the first 3 hours, and then stabilized at the end of anesthesia. In the test group, core temperature decreased during the first 60 minutes, but increased to 36.9 ± 0.3° C at the end of anesthesia. In the control group, eight patients shivered at grade ≥2. In the test group, none of the patients reached grade ≥2 (P < .01). Infusion of warm fluid is effective in keeping patients nearly normothermic and preventing postanesthetic shivering. It may provide an easy and effective method for prevention of perioperative hypothermia. Copyright © 2010 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17313578','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17313578"><span>Molecular analysis of bacterial diversity in kerosene-based drilling fluid from the deep ice borehole at Vostok, East Antarctica.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alekhina, Irina A; Marie, Dominique; Petit, Jean Robert; Lukin, Valery V; Zubkov, Vladimir M; Bulat, Sergey A</p> <p>2007-02-01</p> <p>Decontamination of ice cores is a critical issue in phylogenetic studies of glacial ice and subglacial lakes. At the Vostok drill site, a total of 3650 m of ice core have now been obtained from the East Antarctic ice sheet. The ice core surface is coated with a hard-to-remove film of impure drilling fluid comprising a mixture of aliphatic and aromatic hydrocarbons and foranes. In the present study we used 16S rRNA gene sequencing to analyze the bacterial content of the Vostok drilling fluid sampled from four depths in the borehole. Six phylotypes were identified in three of four samples studied. The two dominant phylotypes recovered from the deepest (3400 and 3600 m) and comparatively warm (-10 degrees C and -6 degrees C, respectively) borehole horizons were from within the genus Sphingomonas, a well-known degrader of polyaromatic hydrocarbons. The remaining phylotypes encountered in all samples proved to be human- or soil-associated bacteria and were presumed to be drilling fluid contaminants of rare occurrence. The results obtained indicate the persistence of bacteria in extremely cold, hydrocarbon-rich environments. They show the potential for contamination of ice and subglacial water samples during lake exploration, and the need to develop a microbiological database of drilling fluid findings.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150007767&hterms=watkins&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwatkins','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150007767&hterms=watkins&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwatkins"><span>Properties of the Lunar Interior: Preliminary Results from the GRAIL Mission</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, James G.; Konopliv, Alexander S.; Asmar, Sami W.; Lemoine, Frank G.; Melosh, H. Jay; Neumann, Gregory A.; Phillips, Roger J.; Smith, David E.; Solomon, Sean C.; Watkins, Michael M.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20150007767'); toggleEditAbsImage('author_20150007767_show'); toggleEditAbsImage('author_20150007767_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20150007767_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20150007767_hide"></p> <p>2013-01-01</p> <p>The Gravity Recovery and Interior Laboratory (GRAIL) mission [1] has provided lunar gravity with unprecedented accuracy and resolution. GRAIL has produced a high-resolution map of the lunar gravity field [2,3] while also determining tidal response. We present the latest gravity field solution and its preliminary implications for the Moon's interior structure, exploring properties such as the mean density, moment of inertia of the solid Moon, and tidal potential Love number k(sub 2). Lunar structure includes a thin crust, a thick mantle layer, a fluid outer core, and a suspected solid inner core. An accurate Love number mainly improves knowledge of the fluid core and deep mantle. In the future, we will search for evidence of tidal dissipation and a solid inner core using GRAIL data.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H13F1445L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H13F1445L"><span>Simultaneous Neutron and X-ray Tomography for Quantitative analysis of Geological Samples</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>LaManna, J.; Hussey, D. S.; Baltic, E.; Jacobson, D. L.</p> <p>2016-12-01</p> <p>Multiphase flow is a critical area of research for shale gas, oil recovery, underground CO2 sequestration, geothermal power, and aquifer management. It is critical to understand the porous structure of the geological formations in addition to the fluid/pore and fluid/fluid interactions. Difficulties for analyzing flow characteristics of rock cores are in obtaining 3D distribution information on the fluid flow and maintaining the cores in a state for other analysis methods. Two powerful non-destructive methods for obtaining 3D structural and compositional information are X-ray and neutron tomography. X-ray tomography produces information on density and structure while neutrons excel at acquiring the liquid phase and produces compositional information. These two methods can offer strong complementary information but are typically conducted at separate times and often at different facilities. This poses issues for obtaining dynamic and stochastic information as the sample will change between analysis modes. To address this, NIST has developed a system that allows for multimodal, simultaneous tomography using thermal neutrons and X-rays by placing a 90 keVp micro-focus X-ray tube 90° to the neutron beam. High pressure core holders that simulate underground conditions have been developed to facilitate simultaneous tomography. These cells allow for the control of confining pressure, axial load, temperature, and fluid flow through the core. This talk will give an overview the simultaneous neutron and x-ray tomography capabilities at NIST, the benefits of multimodal imaging, environmental equipment for geology studies, and several case studies that have been conducted at NIST.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990099279&hterms=Uti&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DUti','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990099279&hterms=Uti&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DUti"><span>Prospect of Continuous VLBI Measurement of Earth Rotation in Monitoring Geophysical Fluids</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chao, Benjamin F.; Ma, Chopo; Clark, Thomas</p> <p>1998-01-01</p> <p>Large-scale mass transports in the geophysical fluids of the Earth system excite Earth's rotational variations in both length-of-day and polar motion. The excitation process is via the conservation of angular momentum. Therefore Earth rotation observations contain information about the integrated angular momentum (consisting of both the mass term and the motion term) of the geophysical fluids, which include atmosphere, hydrosphere, mantle, and the outer and inner cores. Such global information is often important and otherwise unattainable depending on the nature of the mass transport, its magnitude and time scale. The last few years have seen great advances in VLBI measurement of Earth rotation in precision and temporal resolution. These advances have opened new. areas in geophysical fluid studies, such as oceanic tidal angular momentum, atmospheric tides, Earth librations, and rapid atmospheric angular momentum fluctuations. Precision of 10 microseconds in UTI and 200 microarcseconds in polar motion can now be achieved on hourly basis. Building upon this heritage, the multi-network geodetic VLBI project, Continuous Observation of the Rotation of the Earth (CORE), promises to further these studies and to make possible studies on elusive but tell-tale geophysical processes such as oscillatory modes in the core and in the atmosphere. Currently the early phase of CORE is underway. Within a few years into the new mellinnium, the upcoming space gravity missions (such as GRACE) will measure the temporal variations in Earth's gravitational field, thus providing complementary information to that from Earth rotation study for a better understanding of global geophysical fluid processes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S51D..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S51D..03S"><span>Dynamic Dilational Strengthening During Earthquakes in Saturated Gouge-Filled Fault Zones</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sparks, D. W.; Higby, K.</p> <p>2016-12-01</p> <p>The effect of fluid pressure in saturated fault zones has been cited as an important factor in the strength and slip-stability of faults. Fluid pressure controls the effective normal stress across the fault and therefore controls the faults strength. In a fault core consisting of granular fault gouge, local transient dilations and compactions occur during slip that dynamically change the fluid pressure. We use a grain-scale numerical model to investigate the effect of these fluid effects in fault gouge during an earthquake. We use a coupled finite difference-discrete element model (Goren et al, 2011), in which the pore space is filled with a fluid. Local changes in grain packing generate local deviations in fluid pressure, which can be relieved by fluid flow through the permeable gouge. Fluid pressure gradients exert drag forces on the grains that couple the grain motion and fluid flow. We simulated 39 granular gouge zones that were slowly loaded in shear stress to near the failure point, and then conducted two different simulations starting from each grain packing: one with a high enough mean permeability (> 10-11 m2) that pressure remains everywhere equilibrated ("fully drained"), and one with a lower permeability ( 10-14 m2) in which flow is not fast enough to prevent significant pressure variations from developing ("undrained"). The static strength of the fault, the size of the event and the evolution of slip velocity are not imposed, but arise naturally from the granular packing. In our particular granular model, all fully drained slip events are well-modeled by a rapid drop in the frictional resistance of the granular packing from a static value to a dynamic value that remains roughly constant during slip. Undrained events show more complex behavior. In some cases, slip occurs via a slow creep with resistance near the static value. When rapid slip events do occur, the dynamic resistance is typically larger than in drained events, and highly variable. Frictional resistance is not correlated with the mean fluid pressure in the layer, but is instead controlled by local regions undergoing dilational strengthening. We find that (in the absence of pressure-generating effects like thermal pressurization or fluid-releasing reactions), the overall effect of fluid is to strengthen the fault.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AsBio...9..467S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AsBio...9..467S"><span>Microscopic Identification of Prokaryotes in Modern and Ancient Halite, Saline Valley and Death Valley, California</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schubert, Brian A.; Lowenstein, Tim K.; Timofeeff, Michael N.</p> <p>2009-06-01</p> <p>Primary fluid inclusions in halite crystallized in Saline Valley, California, in 1980, 2004-2005, and 2007, contain rod- and coccoid-shaped microparticles the same size and morphology as archaea and bacteria living in modern brines. Primary fluid inclusions from a well-dated (0-100,000 years), 90 m long salt core from Badwater Basin, Death Valley, California, also contain microparticles, here interpreted as halophilic and halotolerant prokaryotes. Prokaryotes are distinguished from crystals on the basis of morphology, optical properties (birefringence), and uniformity of size. Electron micrographs of microparticles from filtered modern brine (Saline Valley), dissolved modern halite crystals (Saline Valley), and dissolved ancient halite crystals (Death Valley) support in situ microscopic observations that prokaryotes are present in fluid inclusions in ancient halite. In the Death Valley salt core, prokaryotes in fluid inclusions occur almost exclusively in halite precipitated in perennial saline lakes 10,000 to 35,000 years ago. This suggests that trapping and preservation of prokaryotes in fluid inclusions is influenced by the surface environment in which the halite originally precipitated. In all cases, prokaryotes in fluid inclusions in halite from the Death Valley salt core are miniaturized (<1 μm diameter cocci, <2.5 μm long, very rare rod shapes), which supports interpretations that the prokaryotes are indigenous to the halite and starvation survival may be the normal response of some prokaryotes to entrapment in fluid inclusions for millennia. These results reinforce the view that fluid inclusions in halite and possibly other evaporites are important repositories of microbial life and should be carefully examined in the search for ancient microorganisms on Earth, Mars, and elsewhere in the Solar System.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/7250371','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/7250371"><span>Method and apparatus utilizing ionizing and microwave radiation for saturation determination of water, oil and a gas in a core sample</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Maerefat, N.L.; Parmeswar, R.; Brinkmeyer, A.D.; Honarpour, M.</p> <p>1994-08-23</p> <p>A system is described for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample. The condensation of heavy hydrocarbon gas and the dynamic characteristics of the fluids are observed with a sight glass at the outlet of the core sample. 11 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010044683&hterms=Xxxii&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DXxxii','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010044683&hterms=Xxxii&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DXxxii"><span>Influence of a Fluid Lunar Core on the Moons Orientation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.; Yoder, C. F.; Dickey, J. O.</p> <p>2001-01-01</p> <p>Oblateness of and dissipation at the lunar liquid-core/solid-mantle boundary affects the precession of core and mantle. Analysis of Lunar Laser ranges gives a weak detection of oblateness and a strong determination of dissipation. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.G33A0411M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.G33A0411M"><span>Lunar internal structure modeling using Apollo seismic travel time data and the latest selenodetic data from GRAIL and LLR</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsumoto, K.; Yamada, R.; Kikuchi, F.; Kamata, S.; Ishihara, Y.; Iwata, T.; Hanada, H.; Sasaki, S.</p> <p>2014-12-01</p> <p>We tried to constrain lunar internal structure by combining the Apollo seismic travel time data and selenodetic data including those from GRAIL and LLR. We used a seven-layer model consisting of crust, upper mantle, middle mantle, lower mantle, low-velocity layer (LVL), fluid outer core and solid inner core. The model is constrained by the following observations; three selenodetic data of mass, mean moment of inertia, tidal Love number k2 from [1], and Apollo seismic travel time data from [2]. Markov Chain Monte Carlo method is used to infer the model parameters. We collected 140 million samples from 10 chains. Viscosity is not taken into account in this calculation. Mean crustal thickness of 46 ± 4 km is estimated by fitting a normal distribution curve to the posterior distribution, which is to be compared with the previous estimate of 34 - 43 km [3]. Major part of crustal densities is sampled between 2500 and 2600 kg/m3, which is consistent with the value of 2550 kg/m3 reported by [3]. In general, seismic wave velocities in the mantle are consistent with the previous estimates [4][5]. The ranges of size and density of the outer core which satisfy the observation are relatively wide and it is difficult to tightly constrain them. Strong correlation between outer core size and LVL thickness is observed. The smaller outer core should be accompanied by thick LVL and vice versa. When we take into account the upper bound of the fluid core size of 400 km which is predicted by magnetic observation [6], the thickness of the LVL is at least about 100 km. The S-wave velocity within this low-velocity layer is estimated to be less than about 3 km/s. The effect of low viscosity [7] may change the estimate of the S-wave velocity in the LVL. The inner core radius is expected to be smaller than 280 km. The lunar displacement Love number is predicted to be h2= 0.0423 ± 0.0004. References [1] Williams et al. (2014), JGR, doi:10.1002/2013JE004559 [2] Lognonne et al. (2003), EPSL, 211, 27-44 [3] Wieczorek et al. (2012), Science, doi:10.1126/science.1231530 [4] Weber et al. (2011), Science, 331, 309-312, doi:10.1126/science.1199375 [5] Garcia et al. (2011), PEPI, doi:10.1016/j.pepi.2011.06.015 [6] Shimizu et al. (2013), Icarus, doi:10.1016/j.icarus.2012.10.029 [7] Harada et al. (2014), Nature geoscience, doi:10.1038/NGEO2211</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5127404','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5127404"><span>The Alzheimer’s Disease Neuroimaging Initiative 2 Biomarker Core: A review of progress and plans</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kang, Ju-Hee; Korecka, Magdalena; Figurski, Michal J.; Toledo, Jon B.; Blennow, Kaj; Zetterberg, Henrik; Waligorska, Teresa; Brylska, Magdalena; Fields, Leona; Shah, Nirali; Soares, Holly; Dean, Robert A.; Vanderstichele, Hugo; Petersen, Ronald C.; Aisen, Paul S.; Saykin, Andrew J.; Weiner, Michael W.; Trojanowski, John Q.; Shaw, Leslie M.</p> <p>2016-01-01</p> <p>Introduction We describe Alzheimer’s Disease Neuroimaging Initiative (ADNI) Biomarker Core progress including: the Biobank; cerebrospinal fluid (CSF) amyloid beta (Aβ1–42), t-tau, and p-tau181 analytical performance, definition of Alzheimer’s disease (AD) profile for plaque, and tangle burden detection and increased risk for progression to AD; AD disease heterogeneity; progress in standardization; and new studies using ADNI biofluids. Methods Review publications authored or coauthored by ADNI Biomarker core faculty and selected non-ADNI studies to deepen the understanding and interpretation of CSF Aβ1–42, t-tau, and p-tau181 data. Results CSFAD biomarker measurements with the qualified AlzBio3 immunoassay detects neuropathologic AD hallmarks in preclinical and prodromal disease stages, based on CSF studies in non-ADNI living subjects followed by the autopsy confirmation of AD. Collaboration across ADNI cores generated the temporal ordering model of AD biomarkers varying across individuals because of genetic/environmental factors that increase/decrease resilience to AD pathologies. Discussion Further studies will refine this model and enable the use of biomarkers studied in ADNI clinically and in disease-modifying therapeutic trials. PMID:26194312</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MMTB...49.1405W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MMTB...49.1405W"><span>Study on the Fluid Flow Characteristics of Coherent Jets with CO2 and O2 Mixed Injection in Electric Arc Furnace Steelmaking Processes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Guangsheng; Zhu, Rong; Wu, Xuetao; Yang, Lingzhi; Dong, Kai; Cheng, Ting; Tang, Tianping</p> <p>2018-06-01</p> <p>As an efficient oxygen supplying technology, coherent jets are widely applied in electric arc furnace (EAF) steelmaking processes to strengthen chemical energy input, speed up smelting rhythm, and promote the uniformity of molten bath temperature and compositions. Recently, the coherent jet with CO2 and O2 mixed injection (COMI) was proposed and demonstrated great application potentiality in reducing the dust production in EAF steelmaking. In the present study, based on the eddy dissipation concept model, a computational fluid dynamics model of coherent jets with COMI was built with the overall and detailed chemical kinetic mechanisms (GRI-Mech 3.0). Compared with one-step combustion reaction, GRI-Mech 3.0 consists of 325 elementary reactions with 53 components and can predict more accurate results. The numerical simulation results were validated by the combustion experiment data. The jet behavior and the fluid flow characteristics of coherent jets with COMI under 298 K and 1700 K (25 °C and 1427 °C) were studied and the results showed that for coherent jets with COMI, the chemical effect of CO2 significantly weakened the shrouding combustion reactions of CH4 and the relative importance of the chemical effect of CO2 increases with CO2 concentration increasing. The potential core length of coherent jet decreases with the volume fraction of CO2 increasing. Moreover, it also can be found that the potential core length of coherent jets was prolonged with higher ambient temperature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MMTB..tmp...64W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MMTB..tmp...64W"><span>Study on the Fluid Flow Characteristics of Coherent Jets with CO2 and O2 Mixed Injection in Electric Arc Furnace Steelmaking Processes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Guangsheng; Zhu, Rong; Wu, Xuetao; Yang, Lingzhi; Dong, Kai; Cheng, Ting; Tang, Tianping</p> <p>2018-03-01</p> <p>As an efficient oxygen supplying technology, coherent jets are widely applied in electric arc furnace (EAF) steelmaking processes to strengthen chemical energy input, speed up smelting rhythm, and promote the uniformity of molten bath temperature and compositions. Recently, the coherent jet with CO2 and O2 mixed injection (COMI) was proposed and demonstrated great application potentiality in reducing the dust production in EAF steelmaking. In the present study, based on the eddy dissipation concept model, a computational fluid dynamics model of coherent jets with COMI was built with the overall and detailed chemical kinetic mechanisms (GRI-Mech 3.0). Compared with one-step combustion reaction, GRI-Mech 3.0 consists of 325 elementary reactions with 53 components and can predict more accurate results. The numerical simulation results were validated by the combustion experiment data. The jet behavior and the fluid flow characteristics of coherent jets with COMI under 298 K and 1700 K (25 °C and 1427 °C) were studied and the results showed that for coherent jets with COMI, the chemical effect of CO2 significantly weakened the shrouding combustion reactions of CH4 and the relative importance of the chemical effect of CO2 increases with CO2 concentration increasing. The potential core length of coherent jet decreases with the volume fraction of CO2 increasing. Moreover, it also can be found that the potential core length of coherent jets was prolonged with higher ambient temperature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22695427','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22695427"><span>Steady-state and time-dependent thermodynamic modeling of the effect of intravenous infusion of warm and cold fluids.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barthel, Erik R; Pierce, James R</p> <p>2012-06-01</p> <p>Hypothermia results in vital sign lability, coagulopathy, wound infections, and other sequelae. Normothermia can be restored by several modalities, including passive blanket heating, warm forced-air devices, and active fluid warming (AFW). In AFW, intravenously administered fluids are heated to 40 to 45 °C to minimize net thermal losses and to raise body temperature. Clinical studies have demonstrated the efficacy of AFW as part of a strategy encompassing several methods, but the isolated contribution of AFW to warming has not been theoretically examined in detail. A calorimetric model is derived to determine the functional dependence of warming on patient weight, hypothermia severity, infusion temperature, and volume infused. A second heat transfer model is derived to describe the time-dependent temperature changes of the periphery and core after warmed-fluid infusion. There is an inverse linear relationship between the patient's initial temperature and the amount of warming achieved with a given volume. In contrast, as the temperature of the infusion approaches the desired final temperature, the volume required for a fixed temperature change increases nonlinearly. For weight-based boluses, the temperature change scales appropriately with patient mass. Infusion of 2 L of room-temperature crystalloid results in a decrease in body temperature of approximately one-third degree Celsius in the average normothermic adult. For the heat transfer model, previously reported rates of temperature drop and recovery after the intravenous infusion of cold fluids are qualitatively reproduced with a blood mixing time of approximately 15 minutes. Our calculations reveal that AFW has a larger measurable beneficial effect for patients with more severe hypothermia, but true rewarming of the patient with AFW alone would require prohibitively large fluid volumes (more than 10 L of 40 °C fluid) or dangerously hot fluid (20 mL/kg of 80 °C fluid for a 1 °C increase). The major beneficial effect of AFW is the prevention of further net heat loss. Copyright © 2012 by Lippincott Williams & Wilkins.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JFM...492..251H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JFM...492..251H"><span>Nonlinear saturation of the Rayleigh instability due to oscillatory flow in a liquid-lined tube</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Halpern, David; Grotberg, James B.</p> <p>2003-10-01</p> <p>In this paper, the stability of core annular flows consisting of two immiscible fluids in a cylindrical tube with circular cross-section is examined. Such flows are important in a wide range of industrial and biomedical applications. For example, in secondary oil recovery, water is pumped into the well to displace the remaining oil. It is also of relevance in the lung, where a thin liquid film coats the inner surface of the small airways of the lungs. In both cases, the flow is influenced by a surface-tension instability, which may induce the breakup of the core fluid into short plugs, reducing the efficiency of the oil recovery, or blocking the passage of air in the lung thus inducing airway closure. We consider the stability of a thin film coating the inner surface of a rigid cylindrical tube with the less viscous fluid in the core. For thick enough films, the Rayleigh instability forms a liquid bulge that can grow to eventually create a plug blocking the tube. The analysis explores the effect of an oscillatory core flow on the interfacial dynamics and particularly the nonlinear stabilization of the bulge. The oscillatory core flow exerts tangential and normal stresses on the interface between the two fluids that are simplified by uncoupling the core and film analyses in the thin-film high-frequency limit of the governing equations. Lubrication theory is used to derive a nonlinear evolution equation for the position of the air liquid interface which includes the effects of the core flow. It is shown that the core flow can prevent plug formation of the more viscous film layer by nonlinear saturation of the capillary instability. The stabilization mechanism is similar to that of a reversing butter knife, where the core shear wipes the growing liquid bulge back on to the tube wall during the main tidal volume stroke, but allows it to grow back as the stoke and shear turn around. To be successful, the leading film thickness ahead of the bulge must be smaller than the trailing film thickness behind it, a requirement necessitating a large enough core capillary number which promotes a large core shear stress on the interface. The core capillary number is defined to be the ratio of core viscous forces to surface tension forces. When this process is tuned correctly, the two phases balance and there is no net growth of the liquid bulge over one cycle. We find that there is a critical frequency above which plug formation does not occur, and that this critical frequency increases as the tidal volume amplitude of the core flow decreases.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615847A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615847A"><span>Drilling the Thuringian Syncline, Germany: core processing during the INFLUINS scientific deep drilling campaign</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abratis, Michael; Methe, Pascal; Aehnelt, Michaela; Kunkel, Cindy; Beyer, Daniel; Kukowski, Nina; Totsche, Kai Uwe</p> <p>2014-05-01</p> <p>Deep drilling of the central Thuringian Syncline was carried out in order to gather substantial knowledge of subsurface fluid dynamics and fluid rock interaction within a sedimentary basin. The final depth of the borehole was successfully reached at 1179 m, just a few meters above the Buntsandstein - Zechstein boundary. One of the aspects of the scientific drilling was obtaining sample material from different stratigraphic units for insights in genesis, rock properties and fluid-rock interactions. Parts of the section were cored whereas cuttings provide record of the remaining units. Coring was conducted in aquifers and their surrounding aquitards, i.e. parts of the Upper Muschelkalk (Trochitenkalk), the Middle Muschelkalk, the Upper Buntsandstein (Pelitrot and Salinarrot) and the Middle Buntsandstein. In advance and in cooperation with the GFZ Potsdam team "Scientific Drilling" core handling was discussed and a workflow was developed to ensure efficient and appropriate processing of the valuable core material and related data. Core curation including cleaning, fitting, marking, measuring, cutting, boxing, photographing and unrolled scanning using a DMT core scanner was carried out on the drilling site in Erfurt. Due care was exercised on samples for microbiological analyses. These delicate samples were immediately cut when leaving the core tube and stored within a cooling box at -78°C. Special software for data input was used developed by smartcube GmbH. Advantages of this drilling information system (DIS) are the compatibility with formats of international drilling projects from the IODP and ICDP drilling programs and thus options for exchanges with the international data bases. In a following step, the drill cores were brought to the national core repository of the BGR in Berlin Spandau where the cores were logged for their physical rock properties using a GeoTek multi sensor core logger (MSCL). After splitting the cores into a working and archive half, the cores were scanned for compositional variations using an XRF core scanner at the BGR lab and scan images of the slabbed surfaces were performed. The average core recovery rate was very high at nearly 100%. Altogether, we gained 533 m of excellent core material including sandstones, siltstones and claystones, carbonates, sulfates and chlorides. This provides valuable insight into the stratigraphic column of the Thuringian Syncline.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040110815','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040110815"><span>Sound Transmission through a Cylindrical Sandwich Shell with Honeycomb Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tang, Yvette Y.; Robinson, Jay H.; Silcox, Richard J.</p> <p>1996-01-01</p> <p>Sound transmission through an infinite cylindrical sandwich shell is studied in the context of the transmission of airborne sound into aircraft interiors. The cylindrical shell is immersed in fluid media and excited by an oblique incident plane sound wave. The internal and external fluids are different and there is uniform airflow in the external fluid medium. An explicit expression of transmission loss is derived in terms of modal impedance of the fluids and the shell. The results show the effects of (a) the incident angles of the plane wave; (b) the flight conditions of Mach number and altitude of the aircraft; (c) the ratios between the core thickness and the total thickness of the shell; and (d) the structural loss factors on the transmission loss. Comparisons of the transmission loss are made among different shell constructions and different shell theories.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMDI33B0415O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMDI33B0415O"><span>Influence of precipitating light elements on stable stratification below the core/mantle boundary</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Rourke, J. G.; Stevenson, D. J.</p> <p>2017-12-01</p> <p>Stable stratification below the core/mantle boundary is often invoked to explain anomalously low seismic velocities in this region. Diffusion of light elements like oxygen or, more slowly, silicon could create a stabilizing chemical gradient in the outermost core. Heat flow less than that conducted along the adiabatic gradient may also produce thermal stratification. However, reconciling either origin with the apparent longevity (>3.45 billion years) of Earth's magnetic field remains difficult. Sub-isentropic heat flow would not drive a dynamo by thermal convection before the nucleation of the inner core, which likely occurred less than one billion years ago and did not instantly change the heat flow. Moreover, an oxygen-enriched layer below the core/mantle boundary—the source of thermal buoyancy—could establish double-diffusive convection where motion in the bulk fluid is suppressed below a slowly advancing interface. Here we present new models that explain both stable stratification and a long-lived dynamo by considering ongoing precipitation of magnesium oxide and/or silicon dioxide from the core. Lithophile elements may partition into iron alloys under extreme pressure and temperature during Earth's formation, especially after giant impacts. Modest core/mantle heat flow then drives compositional convection—regardless of thermal conductivity—since their solubility is strongly temperature-dependent. Our models begin with bulk abundances for the mantle and core determined by the redox conditions during accretion. We then track equilibration between the core and a primordial basal magma ocean followed by downward diffusion of light elements. Precipitation begins at a depth that is most sensitive to temperature and oxygen abundance and then creates feedbacks with the radial thermal and chemical profiles. Successful models feature a stable layer with low seismic velocity (which mandates multi-component evolution since a single light element typically increases seismic velocity) growing to its present-day size while allowing enough precipitation to drive compositional convection below. Crucially, this modeling offers unique constrains on Earth's accretion and the light element composition of the core compared to degenerate estimates derived from bulk density and seismic measurements.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1436048','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1436048"><span>Multi-dimensional simulations of core-collapse supernova explosions with CHIMERA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Messer, Bronson; Harris, James Austin; Hix, William Raphael</p> <p></p> <p>Unraveling the core-collapse supernova (CCSN) mechanism is a problem that remains essentially unsolved despite more than four decades of effort. Spherically symmetric models with otherwise high physical fidelity generally fail to produce explosions, and it is widely accepted that CCSNe are inherently multi-dimensional. Progress in realistic modeling has occurred recently through the availability of petascale platforms and the increasing sophistication of supernova codes. We will discuss our most recent work on understanding neutrino-driven CCSN explosions employing multi-dimensional neutrino-radiation hydrodynamics simulations with the Chimera code. We discuss the inputs and resulting outputs from these simulations, the role of neutrino radiation transport,more » and the importance of multi-dimensional fluid flows in shaping the explosions. We also highlight the production of 48Ca in long-running Chimera simulations.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNG21A1805V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNG21A1805V"><span>Increasing the production efficiency and reducing the environmental impacts of hydraulic fracturing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viswanathan, H. S.</p> <p>2016-12-01</p> <p>Shale gas is an unconventional fossil energy resource profoundly impacting US energy independence and is projected to last for at least 100 years. Production of methane and other hydrocarbons from low permeability shale involves hydraulic fracturing of rock, establishing fracture connectivity, and multiphase fluid-flow and reaction processes all of which are poorly understood. The result is inefficient extraction with many environmental concerns. A science-based capability is required to quantify the governing mesoscale fluid-solid interactions, including microstructural control of fracture patterns and the interaction of engineered fluids with hydrocarbon flow. These interactions depend on coupled thermo-hydro-mechanical-chemical (THMC) processes over scales from microns to tens of meters. Determining the key mechanisms in subsurface THMC systems has been impeded due to the lack of sophisticated experimental methods to measure fracture aperture and connectivity, multiphase permeability, and chemical exchange capacities at the high temperature, pressure, and stresses present in the subsurface. In this study, we developed and prototyped the microfluidic and triaxial core flood experiments required to reveal the fundamental dynamics of fracture-fluid interactions. The goal is transformation of hydraulic fracturing from present ad hoc approaches to science-based strategies while safely enhancing production. Specifically, we have demonstrated an integrated experimental/modeling approach that allows for a comprehensive characterization of fluid-solid interactions and develop models that can be used to determine the reservoir operating conditions necessary to gain a degree of control over fracture generation, fluid flow, and interfacial processes over a range of subsurface conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.B21D..02O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.B21D..02O"><span>DUSEL and the future of deep terrestrial microbiology (Invited)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Onstott, T. C.; Peters, C. A.; Murdoch, L. C.; Elsworth, D.; Sonnenthal, E. L.; Kieft, T.; Boutt, D. F.; Germanovich, L.; Glaser, S. D.; Wang, H. F.; Roggenthen, B.; Lesko, K.; Cushman, P.; Stetler, L. D.; Bang, S.; Anderson, C.</p> <p>2009-12-01</p> <p>DUSEL will take advantage of the existing subsurface architecture of the deepest mine in the U.S. to provide a platform for launching new exploration into the deep terrestrial biosphere. Multi-year experiments are currently being designed to delineate the relationships between microbial diversity and activity and hydraulic connectivity, temperature, pressure, strain rate and multiphase fluids. Unlike the physics experiments, which will be located close to the center of the mine, most of these experiments will be located at the periphery in existing tunnels at 100 to 2400 m depth in order to access fluid fill fractures with boreholes. Hydrological models suggest that DUSEL could sample ~100 km3 volume for microbial biogeographic and transport studies. The high-capacity underground water filtration plant used to generate ultrapure water for neutrino detectors will readily supply water for microbiology coring projects reducing microbial contamination. This will be essential for the drilling platform located at 2400 m depth that will drill down to 7+ km and 120oC in search of the upper temperature limit for life. Another advantage of underground coring is that the drilling fluid pressure will be much less than that of the fracture water, which means that when the coring bit intersects a water-filled fracture, the fracture water will flow into the core barrel reducing the contamination of fracture surfaces in the cores. The ultra-low radiation background counting facility to be located at 1475 m depth will potentially enable 106 times improvement in the detection limit for subsurface microbial respiration rates using radioactive tracers. The Coupled Thermal-Hydrological-Mechanical-Chemical-Biological, block-heating experiment will examine how the microbial communities within fractures respond to the increased thermal and fluid flux. The Fracture Processes Facility is not only designed to determine what controls rock strength, but could also determine to what extent subsurface chemoautotrophic activity is regulated by tectonic episodicity. The DUSEL CO2 Facility will investigate how microbial activity is impacted by CO2 injection and whether microbial activity has a significant impact upon long-term sequestration of CO2. These three experiments represent a subset of the integrated suite of experiments planned for the first 5 years, but many more microbial experiments can be accommodated within DUSEL. With its unique experimental assets, km-scale spatial access and multi-decade observational lifetime, DUSEL will usher in the next generation of exploration into the deep terrestrial biosphere and not only reveal the answers to many of its well-hidden secrets, but perhaps to the origin of life itself.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.8624P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.8624P"><span>New quasi-geostrophic flow estimations for the Earth's core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pais, M. Alexandra</p> <p>2014-05-01</p> <p>Quasi-geostrophic (QG) flows have been reported in numerical dynamo studies that simulate Boussinesq convection of an electrical conducting fluid inside a rapidly rotating spherical shell. In these cases, the required condition for columnar convection seems to be that inertial waves should propagate much faster in the medium than Alfvén waves. QG models are particularly appealing for studies where Earth's liquid core flows are assessed from information contained in geomagnetic data obtained at and above the Earth's surface. Here, they make the whole difference between perceiving only the core surface expression of the geodynamo or else assessing the whole interior core flow. The QG approximation has now been used in different studies to invert geomagnetic field models, providing a different kinematic interpretation of the observed geomagnetic field secular variation (SV). Under this new perspective, a large eccentric jet flowing westward under the Atlantic Hemisphere and a cyclonic column under the Pacific were pointed out as interesting features of the flow. A large eccentric jet with similar characteristics has been explained in recent numerical geodynamo simulations in terms of dynamical coupling between the solid core, the liquid core and the mantle. Nonetheless, it requires an inner core crystallization on the eastern hemisphere, contrary to what has been proposed in recent dynamical models for the inner core. Some doubts remain, as we see, concerning the dynamics that can explain the radial outward flow in the eastern core hemisphere, actually seen in inverted core flow models. This and other puzzling features justify a new assessment of core flows, taking full advantage of the recent geomagnetic field model COV-OBS and of experience, accumulated over the years, on flow inversion. Assuming the QG approximation already eliminates a large part of non-uniqueness in the inversion. Some important non-uniqueness still remains, inherent to the physical model, given our present inability to distinguish the small length scales of the internal geomagnetic field when measuring it at the Earth's surface and above. This can be dealt with in the form of a parameterization error. We recalculated flow models for the whole 1840-2010 period of COV-OBS, using the covariance matrices provided by the authors and an iterative estimation of the parameterization error. Results are compared with previous estimations. We then apply standard tools of Empirical Orthogonal Functions/ Principal Components Analysis to sort out variability modes that, hopefully, can also be identified with dynamical modes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.3893L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.3893L"><span>Direct laboratory observation of fluid distribution and its influence on acoustic properties of patchy saturated rocks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lebedev, M.; Clennell, B.; Pervukhina, M.; Shulakova, V.; Mueller, T.; Gurevich, B.</p> <p>2009-04-01</p> <p>Porous rocks in hydrocarbon reservoirs are often saturated with a mixture of two or more fluids. Interpretation of exploration seismograms requires understanding of the relationship between distribution of the fluids patches and acoustic properties of rocks. The sizes of patches as well as their distribution affect significantly the seismic response. If the size of the fluid patch is smaller than the diffusion wavelength then pressure equilibration is achieved and the bulk modulus of the rock saturated with a mixture is defined by the Gassmann equations (Gassmann, 1951) with the saturation-weighted average of the fluid bulk modulus given by Wood's law (Wood, 1955, Mavko et al., 1998). If the fluid patch size is much larger than the diffusion wavelength then there is no pressure communication between different patches. In this case, fluid-flow effects can be neglected and the overall rock may be considered equivalent to an elastic composite material consisting of homogeneous parts whose properties are given by Gassmann theory with Hill's equation for the bulk modulus (Hill, 1963, Mavko et al., 1998). At intermediate values of fluid saturation the velocity-saturation relationship is significantly affected by the fluid patch distribution. In order to get an improved understanding of factors influencing the patch distribution and the resulting seismic wave response we performed simultaneous measurements of P-wave velocities and rock sample CT imaging. The CT imaging allows us to map the fluid distribution inside rock sample during saturation (water imbibition). We compare the experimental results with theoretical predictions. In this paper we will present results of simultaneous measurements of longitudinal wave velocities and imaging mapping of fluid distribution inside rock sample during sample saturation. We will report results of two kinds of experiments: "dynamic" and "quasi static" saturation. In both experiments Casino Cores Otway Basin sandstone, Australia core samples (38 mm in diameter, approximately 60 mm long) were dried in oven under reduced pressure. In dynamic saturation experiments, samples were jacketed in the experimental cell, made from transparent for X-radiation material (PMMA). Distillate water was injected into the sample from the one side. Fluid distribution in such "dynamic" experiment: both spatial and time dependant was measured using X-ray Computer Tomograph (CT) with resolution 0.2 x 0.2 x 1 mm3. Velocities (Vp, and Vs) at ultrasonic frequency of 1 MHz, were measured in the direction perpendicular to initial direction of the fluid flow injection. Sample saturation was estimated from the CT results. In "quasi static" experiments samples were saturated during long period of time (over 2 weeks) to achieve uniform distribution of liquid inside the sample. Saturation was determined by measurement of the weight of water fraction. All experiments were performed at laboratory environments at temperature 25 C. Ultrasonic velocities and fluid saturations were measured simultaneously during water injection into sandstone core samples. The experimental results obtained on low-permeability samples show that at low saturation values the velocity-saturation dependence can be described by the Gassmann-Wood relationship. However, with increasing saturation a sharp increase of P-wave velocity is observed, eventually approaching the Gassmann-Hill relationship. We connect the characteristics of the transition behavior of the velocity-saturation relationships to the increasing size of the patches inside the rock sample. In particular, we show that for relatively large fluid injection rate this transition occurs at smaller degrees of saturation as compared with high injection rate. We model the experimental data using the so-called White model (Toms 2007) that assumes fluid patch distribution as a periodic assemblage of concentric spheres. We can observe reasonable agreement between experimental results and theoretical predictions of White's model. The results illustrate the non-unique relationships between saturation and velocity in sandstones dependent on texture and fluid displacement history: fuller understanding of these phenomena is needed for accurate assessment of time lapse seismic measurements, be they for oil and gas recovery or for CO2 disposal purposes. Gassmann, F., 1951, Elastic waves through a packing of spheres. Geophysics 16, 673-685; Mavko, G., T. Mukerji, and J. Dvorkin, 1998, The Rock Physics Handbook: Tools for seismic analysis in porous media: Cambridge University Press. Wood, A. W., 1955, A Textbook of Sound, The MacMillan Co., New York, 360 pp. Hill, R., 1963, Elastic properties of reinforced solids: some theoretical principles. J. Mech. Phys. Solids, 11, 357-372. Hill, R., 1952, The elastic behavior of crystalline aggregates. Proc. Physical Soc., London, A65, 349-354. J. Toms, T.M. Mueller, B. Gurevich, 2007 Seismic attenuation in porous rocks with random patchy saturation. Geophysical Prospecting, 55, 671-678.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160007711','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160007711"><span>Space Launch System Booster Separation Aerodynamic Testing in the NASA Langley Unitary Plan Wind Tunnel</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilcox, Floyd J., Jr.; Pinier, Jeremy T.; Chan, David T.; Crosby, William A.</p> <p>2016-01-01</p> <p>A wind-tunnel investigation of a 0.009 scale model of the Space Launch System (SLS) was conducted in the NASA Langley Unitary Plan Wind Tunnel to characterize the aerodynamics of the core and solid rocket boosters (SRBs) during booster separation. High-pressure air was used to simulate plumes from the booster separation motors (BSMs) located on the nose and aft skirt of the SRBs. Force and moment data were acquired on the core and SRBs. These data were used to corroborate computational fluid dynamics (CFD) calculations that were used in developing a booster separation database. The SRBs could be remotely positioned in the x-, y-, and z-direction relative to the core. Data were acquired continuously while the SRBs were moved in the axial direction. The primary parameters varied during the test were: core pitch angle; SRB pitch and yaw angles; SRB nose x-, y-, and z-position relative to the core; and BSM plenum pressure. The test was conducted at a free-stream Mach number of 4.25 and a unit Reynolds number of 1.5 million per foot.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.B52B..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.B52B..06S"><span>Geochemical and hydrological constraints on the deep subsurface terrestrial ecosystems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silver, B.; Onstott, T.; Hinton, S.; King, H.; Sherwood Lollar, B.; Lippmann-Pipke, J.</p> <p>2008-12-01</p> <p>Pore water and fluid inclusion compositions were determined on pristine rock cores from the Ventersdorp and Witwatersrand Supergroup by leaching experiments in order to constrain the origin of the chemical nutrients in the fracture water of the Witwatersrand basin. Subsequent chemical extractions including fusion analyses of the rock cores constrained the redox relevant mineral abundances of these strata. The resulting data set was used in mixing models with meteoric water from the overlying Transvaal dolomitic aquifer. The model also incorporated dissolved gas concentrations, radiogenic and radiolytic reactions, mineral dissolution and oxidation reactions, mineral equilibria and microbial redox reactions at rates that were varied over the course of one million years. Results revealed pore water and fluid inclusion leachates rich in Na, Ca, Si, Cl, acetate, SO42- and formate, with the resulting inferred fluid inclusion concentrations exceeding pore water concentrations, which in turn exceeded fracture water concentrations in nearly all observed elements. The model successfully simulated dissolved He and Cl concentrations with a mixing rate of 1e-5 L/year, corresponding to a fracture water velocity of 1 mm/year. Upon examining the viability of Fe reduction, SO42- reduction, acetogenesis, methanogenesis, NO3- reduction, anaerobic NH3 oxidation and HS- oxidation, model results indicate that SO42-reduction is the dominant metabolic process at high and low salinities and can be sustained at rates of 1.2e-12 M SO42- s-1 for biomasses of 2e8 cells/mL water. Final electron acceptor and donor concentrations and Free Energy Flux (FEF) calculations suggest that acetogenesis is not the source of acetate, nor is the syntrophic degradation of light hydrocarbons the source of the observed carboxylic acids. Ambient concentrations are instead likely the result of production via the thermally activated step-wise decarboxylation of abiogenic hydrocarbons and consumption by carboxylic acid utilizing metabolic reactions consistent with phylogenetic data showing few acetogens, no hydrocarbon oxidizers and a significant abundance of acetoclastic methanogens.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930028523&hterms=new+star&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnew%2Bstar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930028523&hterms=new+star&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnew%2Bstar"><span>A new class of g-modes in neutron stars</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reisenegger, Andreas; Goldreich, Peter</p> <p>1992-01-01</p> <p>Because a neutron star is born hot, its internal composition is close to chemical equilibrium. In the fluid core, this implies that the ratio of the number densities of charged particles (protons and electrons) to neutrons is an increasing function of the mass density. This composition gradient stably stratifies the matter giving rise to a Brunt-Vaisala frequency N of about 500/s. Consequently, a neutron star core provides a cavity that supports gravity modes (g-modes). These g-modes are distinct from those previously identified with the thermal stratification of the surface layers and the chemical stratification of the crust. We compute the lowest-order, quadrupolar, g-modes for cold, Newtonian, neutron star models with M/solar M = 0.581 and M/solar M = 1.405, and show that the crustal and core g-modes have similar periods. We also discuss damping mechanisms and estimate damping rates for the core g-modes. Particular attention is paid to damping due to the emission of gravitational radiation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940014365','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940014365"><span>Research on Earth's rotation and the effect of atmospheric pressure on vertical deformation and sea level variability</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wahr, John</p> <p>1993-01-01</p> <p>The work done under NASA grant NAG5-485 included modelling the deformation of the earth caused by variations in atmospheric pressure. The amount of deformation near coasts is sensitive to the nature of the oceanic response to the pressure. The PSMSL (Permanent Service for Mean Sea Level) data suggest the response is inverted barometer at periods greater than a couple months. Green's functions were constructed to describe the perturbation of the geoid caused by atmospheric and oceanic loading and by the accompanying load-induced deformation. It was found that perturbation of up to 2 cm are possible. Ice mass balance data was used for continental glaciers to look at the glacial contributions to time-dependent changes in polar motion, the lod, the earth's gravitational field, the position of the earth's center-of-mass, and global sea level. It was found that there can be lateral, non-hydrostatic structure inside the fluid core caused by gravitational forcing from the mantle, from the inner core, or from topography at the core/mantle or inner core/outer core boundaries. The nutational and tidal response of a non-hydrostatic earth with a solid inner core was modeled. Monthly, global tide gauge data from PSMSL was used to look at the 18.6-year ocean tide, the 14-month pole tide, the oceanic response to pressure, the linear trend and inter-annual variability in the earth's gravity field, the global sea level rise, and the effects of post glacial rebound. The effects of mantle anelasticity on nutations, earth tides, and tidal variation in the lod was modeled. Results of this model can be used with Crustal Dynamics observations to look at the anelastic dissipation and dispersion at tidal periods. The effects of surface topography on various components of crustal deformation was also modeled, and numerical models were developed of post glacial rebound.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000GeoJI.141..485R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000GeoJI.141..485R"><span>Core flow inversion tested with numerical dynamo models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rau, Steffen; Christensen, Ulrich; Jackson, Andrew; Wicht, Johannes</p> <p>2000-05-01</p> <p>We test inversion methods of geomagnetic secular variation data for the pattern of fluid flow near the surface of the core with synthetic data. These are taken from self-consistent 3-D models of convection-driven magnetohydrodynamic dynamos in rotating spherical shells, which generate dipole-dominated magnetic fields with an Earth-like morphology. We find that the frozen-flux approximation, which is fundamental to all inversion schemes, is satisfied to a fair degree in the models. In order to alleviate the non-uniqueness of the inversion, usually a priori conditions are imposed on the flow; for example, it is required to be purely toroidal or geostrophic. Either condition is nearly satisfied by our model flows near the outer surface. However, most of the surface velocity field lies in the nullspace of the inversion problem. Nonetheless, the a priori constraints reduce the nullspace, and by inverting the magnetic data with either one of them we recover a significant part of the flow. With the geostrophic condition the correlation coefficient between the inverted and the true velocity field can reach values of up to 0.65, depending on the choice of the damping parameter. The correlation is significant at the 95 per cent level for most spherical harmonic degrees up to l=26. However, it degrades substantially, even at long wavelengths, when we truncate the magnetic data sets to l <= 14, that is, to the resolution of core-field models. In some of the latter inversions prominent zonal currents, similar to those seen in core-flow models derived from geomagnetic data, occur in the equatorial region. However, the true flow does not contain this flow component. The results suggest that some meaningful information on the core-flow pattern can be retrieved from secular variation data, but also that the limited resolution of the magnetic core field could produce serious artefacts.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790016961','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790016961"><span>Review of coaxial flow gas core nuclear rocket fluid mechanics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weinstein, H.</p> <p>1976-01-01</p> <p>Almost all of the fluid mechanics research associated with the coaxial flow gas core reactor ended abruptly with the interruption of NASA's space nuclear program because of policy and budgetary considerations in 1973. An overview of program accomplishments is presented through a review of the experiments conducted and the analyses performed. Areas are indicated where additional research is required for a fuller understanding of cavity flow and of the factors which influence cold and hot flow containment. A bibliography is included with graphic material.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25354303','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25354303"><span>Leatherbacks swimming in silico: modeling and verifying their momentum and heat balance using computational fluid dynamics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dudley, Peter N; Bonazza, Riccardo; Jones, T Todd; Wyneken, Jeanette; Porter, Warren P</p> <p>2014-01-01</p> <p>As global temperatures increase throughout the coming decades, species ranges will shift. New combinations of abiotic conditions will make predicting these range shifts difficult. Biophysical mechanistic niche modeling places bounds on an animal's niche through analyzing the animal's physical interactions with the environment. Biophysical mechanistic niche modeling is flexible enough to accommodate these new combinations of abiotic conditions. However, this approach is difficult to implement for aquatic species because of complex interactions among thrust, metabolic rate and heat transfer. We use contemporary computational fluid dynamic techniques to overcome these difficulties. We model the complex 3D motion of a swimming neonate and juvenile leatherback sea turtle to find power and heat transfer rates during the stroke. We combine the results from these simulations and a numerical model to accurately predict the core temperature of a swimming leatherback. These results are the first steps in developing a highly accurate mechanistic niche model, which can assists paleontologist in understanding biogeographic shifts as well as aid contemporary species managers about potential range shifts over the coming decades.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H43G1728S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H43G1728S"><span>Validating predictions of evolving porosity and permeability in carbonate reservoir rocks exposed to CO2-brine</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, M. M.; Hao, Y.; Carroll, S.</p> <p>2017-12-01</p> <p>Improving our ability to better forecast the extent and impact of changes in porosity and permeability due to CO2-brine-carbonate reservoir interactions should lower uncertainty in long-term geologic CO2 storage capacity estimates. We have developed a continuum-scale reactive transport model that simulates spatial and temporal changes to porosity, permeability, mineralogy, and fluid composition within carbonate rocks exposed to CO2 and brine at storage reservoir conditions. The model relies on two primary parameters to simulate brine-CO2-carbonate mineral reaction: kinetic rate constant(s), kmineral, for carbonate dissolution; and an exponential parameter, n, relating porosity change to resulting permeability. Experimental data collected from fifteen core-flooding experiments conducted on samples from the Weyburn (Saskatchewan, Canada) and Arbuckle (Kansas, USA) carbonate reservoirs were used to calibrate the reactive-transport model and constrain the useful range of k and n values. Here we present the results of our current efforts to validate this model and the use of these parameter values, by comparing predictions of extent and location of dissolution and the evolution of fluid permeability against our results from new core-flood experiments conducted on samples from the Duperow Formation (Montana, USA). Agreement between model predictions and experimental data increase our confidence that these parameter ranges need not be considered site-specific but may be applied (within reason) at various locations and reservoirs. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993Metic..28R.455W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993Metic..28R.455W"><span>The Role of Body Crystallization in Asteroidal Cores</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wasson, J. T.</p> <p>1993-07-01</p> <p>Large fractionations (factors of 2000-6000) in Ir/Ni and other ratios demonstrate that the magmatic groups of iron meteorites formed by fractional crystallization, and thus that the residual liquid remained well stirred during core crystallization. Past models have relied on solidification at the base or the top of the core, but body crystallization offers an attractive alternative. The simplest of the earlier models involved convective maxing induced by the liberation of heat and light elements (especially S) during upward crystallization from the center of the core. Other models involving downward crystallization from the core-mantle interface are based on the fact that temperatures at this location are slightly lower than those at the center; no whole-core stirring mechanism is provided by these models. Haack and Scott recently published a variant of the downward crystallization model involving the growth of giant (kilometer-scale) dendrites. Because crystallization creates a boundary layer enriched in S that does not participate in the convection, these models require several K of supercooling to induce crystallization (this undercooling is much greater than the temperature difference between the center of the core and the core-mantle interface). Buoyant forces will occasionally remove droplets of the basal boundary fluid; thus it was thinner and its degree of undercooling less than in that at the ceiling of the magma chamber. Homogeneous nucleation of metals is difficult to achieve; generally 200-300 K of undercooling is required, much more than could possibly occur in an asteroidal core. Crystals could, however, nucleate in the magma body on chromite, probably the first liquidus phase (A. Kracher, personal communication, notes that this is required to explain why Cr behaved like a compatible element despite having a solid/liquid D < 1). In addition, some tiny, submillimeter dendrites that formed at the top of the core must have pinched off and fallen into the magma. Such seeds settle as a result of buoyant forces (thus stirring the magma) and, as a result, achieve very thin boundary layers and require low degrees of undercooling in order to crystallize. The rate of core crystallization is limited by the rate of heat transport across the core-mantle interface. If sufficient nuclei are available at different sites, the bulk of the crystallization occurs where undercooling is least. It is possible that a larger fraction of the total crystallization occurred in the body of the magma than at its base or ceiling.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5416542-emergency-deployable-core-catcher','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5416542-emergency-deployable-core-catcher"><span>Emergency deployable core catcher</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Rosewell, M.P.</p> <p></p> <p>An emergency melt down core catcher apparatus for a nuclear reactor having a retrofitable eutectic solute holding vessel connected to a core containment vessel with particle transferring fluid and particles or granules of solid eutectic solute materials contained therein and transferable by automatically operated valve means to transport and position the solid eutectic solute material in a position below the core to catch and react with any partial or complete melt down of the fuel core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1265266-plasma-response-measurements-non-axisymmetric-magnetic-perturbations-diii-via-soft-ray-imaging','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1265266-plasma-response-measurements-non-axisymmetric-magnetic-perturbations-diii-via-soft-ray-imaging"><span>Plasma response measurements of non-axisymmetric magnetic perturbations on DIII-D via soft x-ray imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Shafer, Morgan W.; Unterberg, Ezekial A.; Wingen, Andreas; ...</p> <p>2014-12-29</p> <p>Recent observations on DIII-D have advanced the understanding of plasma response to applied resonant magnetic perturbations (RMPs) in both H-mode and L-mode plasmas. Three distinct 3D features localized in minor radius are imaged via filtered soft x-ray emission: (i) the formation of lobes extending from the unperturbed separatrix in the X-point region at the plasma boundary, (ii) helical kink-like perturbations in the steep-gradient region inside the separatrix, and (iii) amplified islands in the core of a low-rotation L-mode plasma. In this study, these measurements are used to test and to validate plasma response models, which are crucial for providing predictivemore » capability of edge-localized mode control. In particular, vacuum and two-fluid resistive magnetohydrodynamic(MHD) responses are tested in the regions of these measurements. At the plasma boundary in H-mode discharges with n = 3 RMPs applied, measurements compare well to vacuum-field calculations that predict lobe structures. Yet in the steep-gradient region, measurements agree better with calculations from the linear resistive two-fluid MHD code, M3D-C1. Relative to the vacuum fields, the resistive two-fluid MHD calculations show a reduction in the pitch-resonant components of the normal magnetic field (screening), and amplification of non-resonant components associated with ideal kink modes. However, the calculations still over-predict the amplitude of the measuredperturbation by a factor of 4. In a slowly rotating L-mode plasma with n = 1 RMPs, core islands are observed amplified from vacuum predictions. Finally, these results indicate that while the vacuum approach describes measurements in the edge region well, it is important to include effects of extended MHD in the pedestal and deeper in the plasma core.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29775712','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29775712"><span>Rheological and fracturing characteristics of a novel sulfonated hydroxypropyl guar gum.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qiu, Liewei; Shen, Yiding; Wang, Tao; Wang, Chen</p> <p>2018-05-15</p> <p>A series of sulfonated hydroxypropyl guar gum (SHG) samples with different degrees of substitution (DSs) were prepared, and the SHG solution and SHG fracturing fluid were prepared and analyzed. The SHG aqueous solutions with different DSs all exhibit shear thinning behavior, which is well correlated with the Ostwald-deWaele model. Owing to the electrostatic repulsion of SHG molecular chains, SHG solutions with a higher DS will exhibit weaker thixotropic performance and strong anti-salinity ability. In addition, the SHG fracturing fluids, which were formed by interactions between SHG and organic zirconium, exhibit good temperature- and shear-resistant properties, proppant suspension properties, and salt tolerance. Furthermore, SHG gel-breaking fluids show low interfacial and surface tensions, with low residue content and small core permeability damage. These results provide useful indicators for the applications of SHG in the oil field industry. Copyright © 2017. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFDE38002S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFDE38002S"><span>Viscoplastic sculpting in stable triple layer heavy oil transport flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarmadi, Parisa; Hormozi, Sarah; A. Frigaard, Ian</p> <p>2017-11-01</p> <p>In we introduced a novel methodology for efficient transport of heavy oil via a triple layer core-annular flow. Pumping pressures are significantly reduced by concentrating high shear rates to a lubricating layer, while ideas from Visco-Plastic Lubrication are used to eliminate interfacial instabilities. We purposefully position a shaped unyielded skin of a viscoplastic fluid between the transported oil and the lubricating fluid layer to balance the density difference between the fluids. Here we address the sculpting of the shaped skin within a concentric inflow manifold. We use the quasi-steady model to provide inputs to an axisymmetric triple layer computation, showing the development of the streamwise skin profile and establishment of the flow. For this, we use a finite element discretization with the augmented-Lagrangian method to represent the yield surface behaviour accurately and a PLIC method to track the interface motion.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/10177714','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/10177714"><span>DOE workshop: Sedimentary systems, aqueous and organic geochemistry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Not Available</p> <p>1993-07-01</p> <p>A DOE workshop on sedimentary systems, aqueous and organic geochemistry was held July 15-16, 1993 at Lawrence Berkeley Laboratory. Papers were organized into several sections: Fundamental Properties, containing papers on the thermodynamics of brines, minerals and aqueous electrolyte solutions; Geochemical Transport, covering 3-D imaging of drill core samples, hydrothermal geochemistry, chemical interactions in hydrocarbon reservoirs, fluid flow model application, among others; Rock-Water Interactions, with presentations on stable isotope systematics of fluid/rock interaction, fluid flow and petotectonic evolution, grain boundary transport, sulfur incorporation, tracers in geologic reservoirs, geothermal controls on oil-reservoir evolution, and mineral hydrolysis kinetics; Organic Geochemistry covered new methodsmore » for constraining time of hydrocarbon migration, kinetic models of petroleum formation, mudstones in burial diagenesis, compound-specific carbon isotope analysis of petroleums, stability of natural gas, sulfur in sedimentary organic matter, organic geochemistry of deep ocean sediments, direct speciation of metal by optical spectroscopies; and lastly, Sedimentary Systems, covering sequence stratigraphy, seismic reflectors and diagenetic changes in carbonates, geochemistry and origin of regional dolomites, and evidence of large comet or asteroid impacts at extinction boundaries.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDG25004R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDG25004R"><span>Investigation of mucus transport in an idealized lung airway model using multiphase CFD analysis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajendran, Rahul; Banerjee, Arindam</p> <p>2015-11-01</p> <p>Mucus, a Bingham fluid is transported in the pulmonary airways by consistent beating of the cilia and exhibits a wide range of physical properties in response to the core air flow and various pathological conditions. A better understanding of the interfacial instability is required as it plays a crucial role in gas transport, mixing, mucus clearance and drug delivery. In the current study, mucus is modelled as a Newtonian fluid and the two phase gas-liquid flow in the airways is investigated using an inhomogeneous Eulerian-Eulerian approach. The complex interface between the phases is tracked using the conventional VOF (Volume of Fluid) method. Results from our CFD simulations which are performed in idealized single and double bifurcation geometries will be presented and the influence of airflow rate, mucus layer thickness, mucus viscosity, airway geometry (branching & diameter) and surface tension on mucus flow behavior will be discussed. Mean mucus layer thickness, pressure drop due to momentum transfer & increased airway resistance, mucus transport speed and the flow morphology will be compared to existing experimental and theoretical data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/350312','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/350312"><span>Spiral wound extraction cartridge</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wisted, E.E.; Lundquist, S.H.</p> <p>1999-04-27</p> <p>A cartridge device for removing an analyte from a fluid comprises a hollow core, a sheet composite comprising a particulate-loaded porous membrane and optionally at least one reinforcing spacer sheet, the particulate being capable of binding the analyte, the sheet composite being formed into a spiral configuration about the core, wherein the sheet composite is wound around itself and wherein the windings of sheet composite are of sufficient tightness so that adjacent layers are essentially free of spaces therebetween, two end caps which are disposed over the core and the lateral ends of the spirally wound sheet composite, and means for securing the end caps to the core, the end caps also being secured to the lateral ends of the spirally wound sheet composite. A method for removing an analyte from a fluid comprises the steps of providing a spirally wound element of the invention and passing the fluid containing the analyte through the element essentially normal to a surface of the sheet composite so as to bind the analyte to the particulate of the particulate-loaded porous membrane, the method optionally including the step of eluting the bound analyte from the sheet composite. 4 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1913b0022H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1913b0022H"><span>A counter-rotating vortex pair in inviscid fluid</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habibah, Ummu; Fukumoto, Yasuhide</p> <p>2017-12-01</p> <p>We study the motion of a counter-rotating vortex pair with the circulations ±Γ move in incompressible fluid. The assumption is made that the core is very thin, that is the core radius σ is much smaller than the vortex radius d such that ɛ = σ/d ≪ 1. With this condition, the method of matched asymptotic expansion is employed. The solutions of the Navier-Stokes equations and the Biot-Savart law, regarding the inner and outer solutions respectively, are constructed in the form of a small parameter. An asymptotic expansion of the Biot-Savart law near the vortex core provides with the matching condition for an asymptotic expansion for limiting the Navier-Stokes equations for large radius r. The general formula of an anti-parallel vortex pair is established. At leading order O(ɛ0), we apply the special case in inviscid fluid, the Rankine vortex, a circular vortex of uniform vorticity. Furthermore at leading order O(ɛ5) we show the traveling speed of a vortex pair.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816084V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816084V"><span>Stress dependence of permeability of intact and fractured shale cores.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Noort, Reinier; Yarushina, Viktoriya</p> <p>2016-04-01</p> <p>Whether a shale acts as a caprock, source rock, or reservoir, understanding fluid flow through shale is of major importance for understanding fluid flow in geological systems. Because of the low permeability of shale, flow is thought to be largely confined to fractures and similar features. In fracking operations, fractures are induced specifically to allow for hydrocarbon exploration. We have constructed an experimental setup to measure core permeabilities, using constant flow or a transient pulse. In this setup, we have measured the permeability of intact and fractured shale core samples, using either water or supercritical CO2 as the transporting fluid. Our measurements show decreasing permeability with increasing confining pressure, mainly due to time-dependent creep. Furthermore, our measurements show that for a simple splitting fracture, time-dependent creep will also eliminate any significant effect of this fracture on permeability. This effect of confinement on fracture permeability can have important implications regarding the effects of fracturing on shale permeability, and hence for operations depending on that.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4354668','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4354668"><span>Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Andrew, Matthew; Bijeljic, Branko; Blunt, Martin</p> <p>2015-01-01</p> <p>X-ray microtomography was used to image, at a resolution of 6.6 µm, the pore-scale arrangement of residual carbon dioxide ganglia in the pore-space of a carbonate rock at pressures and temperatures representative of typical formations used for CO2 storage. Chemical equilibrium between the CO2, brine and rock phases was maintained using a high pressure high temperature reactor, replicating conditions far away from the injection site. Fluid flow was controlled using high pressure high temperature syringe pumps. To maintain representative in-situ conditions within the micro-CT scanner a carbon fiber high pressure micro-CT coreholder was used. Diffusive CO2 exchange across the confining sleeve from the pore-space of the rock to the confining fluid was prevented by surrounding the core with a triple wrap of aluminum foil. Reconstructed brine contrast was modeled using a polychromatic x-ray source, and brine composition was chosen to maximize the three phase contrast between the two fluids and the rock. Flexible flow lines were used to reduce forces on the sample during image acquisition, potentially causing unwanted sample motion, a major shortcoming in previous techniques. An internal thermocouple, placed directly adjacent to the rock core, coupled with an external flexible heating wrap and a PID controller was used to maintain a constant temperature within the flow cell. Substantial amounts of CO2 were trapped, with a residual saturation of 0.203 ± 0.013, and the sizes of larger volume ganglia obey power law distributions, consistent with percolation theory. PMID:25741751</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNG23A1479V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNG23A1479V"><span>Topographic-driven instabilities in terrestrial bodies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vantieghem, S.; Cebron, D.; Herreman, W.; Lacaze, L.</p> <p>2013-12-01</p> <p>Models of internal planetary fluid layers (core flows, subsurface oceans) commonly assume that these fluid envelopes have a spherical shape. This approximation however entails a serious restriction from the fluid dynamics point of view. Indeed, in the presence of mechanical forcings (precession, libration, nutation or tides) due to gravitational interaction with orbiting partners, boundary topography (e.g. of the core-mantle boundary) may excite flow instabilities and space-filling turbulence. These phenomena may affect heat transport and dissipation at the main order. Here, we focus on instabilities driven by longitudinal libration. Using a suite of theoretical tools and numerical simulations, we are able to discern a parameter range for which instability may be excited. We thereby consider deformations of different azimuthal order. This study gives the first numerical evidence of the tripolar instability. Furthermore, we explore the non-linear regime and investigate the amplitude as well as the dissipation of the saturated instability. Indeed, these two quantities control the torques on the solid layers and the thermal transport. Furthermore, based on this results, we address the issue of magnetic field generation associated with these flows (by induction or by dynamo process). This instability mechanism applies to both synchronized as non-synchronized bodies. As such, our results show that a tripolar instability might be present in various terrestrial bodies (Early Moon, Gallilean moons, asteroids, etc.), where it could participate in dynamo action. Simulation of a libration-driven tripolar instability in a deformed spherical fluid layer: snapshot of the velocity magnitude, where a complex 3D flow pattern is established.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H12A..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H12A..04S"><span>Monitoring carbonate dissolution using spatially resolved under-sampled NMR propagators and MRI</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sederman, A. J.; Colbourne, A.; Mantle, M. D.; Gladden, L. F.; Oliveira, R.; Bijeljic, B.; Blunt, M. J.</p> <p>2017-12-01</p> <p>The dissolution of a porous rock matrix by an acidic flow causes a change in the pore structure and consequently the pattern of fluid flow and rock permeability. This process is relevant to many areas of practical relevance such as enhanced oil recovery, water contaminant migration and sequestration of supercritical CO2. The most important governing factors for the type of change in the pore space are related by the Péclet (Pe) and Damköhler (Da) dimensionless numbers; these compare the transport properties of the fluid in the porous medium with the reactive properties of the solid matrix and the incident fluid respectively. Variation in Pe and Da can cause very different evolution regimes of the pore space and flow can occur, ranging from a uniform dissolution through different "wormholing" regimes (shown on the left hand side of figure 1) to face dissolution. NMR has a unique capability of measuring both the flow and structural changes during such dissolution whilst the characteristics of flow in the highly heterogeneous matrix that is formed can be predicted by the CTRW modelling approach. Here, NMR measurements of displacement probability distributions, or propagators, have been used to monitor the evolution of fluid flow during a reactive dissolution rock core floods. Developments in the NMR method by undersampling the acquisition data enable spatially resolved measurements of the propagators to be done at sufficient displacement resolution and in a timescale that is short enough to capture the changes in structure and flow. The highly under-sampled (4%) data, which typically reduces the acquisition time from 2 hours to 6 minutes, has been shown to produce equivalent propagator results to the fully sampled experiment. Combining these propagator measurements with quantitative and fast imaging techniques a full time-resolved picture of the dissolution reaction is built up. Experiments have been done for both Ketton and Estaillades carbonate rock cores, which exhibit very different dissolution behaviours, and for which experiments and model comparisons will be shown.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.H51B..01B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.H51B..01B"><span>Experimental Analysis of the Role of Fluid Transport Properties in Fluid-Induced Fracture Initiation and Propagation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boutt, D.; McPherson, B. J.; Cook, B. K.; Goodwin, L. B.; Williams, J. R.; Lee, M. Y.; Patteson, R.</p> <p>2003-12-01</p> <p>It is well known that pore fluid pressure fundamentally influences a rock's mechanical response to stress. However, most measures of the mechanical behavior of rock (e.g. shear strength, Young's modulus) do not incorporate, either explicitly or implicitly, pore fluid pressure or transport properties of rock. Current empirical and theoretical criteria that define the amount of stress a given body of rock can support before fracturing also lack a direct connection between fluid transport and mechanical properties. Our research goal is to use laboratory experimental results to elucidate correlations between rock transport properties and fracture behavior under idealized loading conditions. In strongly coupled fluid-solid systems the evolution of the solid framework is influenced by the fluid and vice versa. These couplings often result in changes of the bulk material properties (i.e. permeability and failure strength) with respect to the fluid's ability to move through the solid and the solids ability to transmit momentum. Feedbacks between fluid and solid framework ultimately play key roles in understanding the spatial and temporal evolution of the coupled fluid-solid system. Discretely coupled models of fluid and solid mechanics were developed a priori to design an experimental approach for testing the role of fluid transport parameters in rock fracture. The experimental approach consists of first loading a fluid saturated cylindrical rock specimen under hydrostatic conditions and then applying a differential stress such that the maximum stress is perpendicular to the cylinder long axis. At the beginning of the test the minimum stress and the fluid pressure are dropped at the same time such that the resulting difference in the initial fluid pressure and the final fluid pressure is greater than the final minimum stress. These loading conditions should produce a fluid driven tensile fracture that is perpendicular to the cylinder long axis. Initial analyses using numerical simulations with similar boundary conditions suggest that resulting fracture propagation rates and fracture spacing are controlled by the rocks hydraulic diffusivity. Modeled rocks with higher permeability had fractures with larger apertures, more localized deformation, and greater fracture spacing. Intuitively, these results are consistent with permeability controlling the time required for pressure to come to equilibrium with the new boundary conditions. Finally, more general goals of this research include using these core-scale experimental data and discrete simulation results to calibrate larger-scale, more traditional continuum models of geologic deformation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031927','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031927"><span>A deep crustal fluid channel into the San Andreas Fault system near Parkfield, California</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Becken, M.; Ritter, O.; Park, S.K.; Bedrosian, P.A.; Weckmann, U.; Weber, M.</p> <p>2008-01-01</p> <p>Magnetotelluric (MT) data from 66 sites along a 45-km-long profile across the San Andreas Fault (SAF) were inverted to obtain the 2-D electrical resistivity structure of the crust near the San Andreas Fault Observatory at Depth (SAFOD). The most intriguing feature of the resistivity model is a steeply dipping upper crustal high-conductivity zone flanking the seismically defined SAF to the NE, that widens into the lower crust and appears to be connected to a broad conductivity anomaly in the upper mantle. Hypothesis tests of the inversion model suggest that upper and lower crustal and upper-mantle anomalies may be interconnected. We speculate that the high conductivities are caused by fluids and may represent a deep-rooted channel for crustal and/or mantle fluid ascent. Based on the chemical analysis of well waters, it was previously suggested that fluids can enter the brittle regime of the SAF system from the lower crust and mantle. At high pressures, these fluids can contribute to fault-weakening at seismogenic depths. These geochemical studies predicted the existence of a deep fluid source and a permeable pathway through the crust. Our resistivity model images a conductive pathway, which penetrates the entire crust, in agreement with the geochemical interpretation. However, the resistivity model also shows that the upper crustal branch of the high-conductivity zone is located NE of the seismically defined SAF, suggesting that the SAF does not itself act as a major fluid pathway. This interpretation is supported by both, the location of the upper crustal high-conductivity zone and recent studies within the SAFOD main hole, which indicate that pore pressures within the core of the SAF zone are not anomalously high, that mantle-derived fluids are minor constituents to the fault-zone fluid composition and that both the volume of mantle fluids and the fluid pressure increase to the NE of the SAF. We further infer from the MT model that the resistive Salinian block basement to the SW of the SAFOD represents an isolated body, being 5-8km wide and reaching to depths >7km, in agreement with aeromagnetic data. This body is separated from a massive block of Salinian crust farther to the SW. The NE terminus of resistive Salinian crust has a spatial relationship with a near-vertical zone of increased seismic reflectivity ???15km SW of the SAF and likely represents a deep-reaching fault zone. ?? 2008 The Authors Journal compilation ?? 2008 RAS.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24790437','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24790437"><span>Electrosprayed core-shell solid dispersions of acyclovir fabricated using an epoxy-coated concentric spray head.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Zhe-Peng; Cui, Lei; Yu, Deng-Guang; Zhao, Zhuan-Xia; Chen, Lan</p> <p>2014-01-01</p> <p>A novel structural solid dispersion (SD) taking the form of core-shell microparticles for poorly water-soluble drugs is reported for the first time. Using polyvinylpyrrolidone (PVP) as a hydrophilic polymer matrix, the SDs were fabricated using coaxial electrospraying (characterized by an epoxy-coated concentric spray head), although the core fluids were unprocessable using one-fluid electrospraying. Through manipulating the flow rates of the core drug-loaded solutions, two types of core-shell microparticles with tunable drug contents were prepared. They had average diameters of 1.36±0.67 and 1.74±0.58 μm, and were essentially a combination of nanocomposites with the active ingredient acyclovir (ACY) distributed in the inner core, and the sweeter sucralose and transmembrane enhancer sodium dodecyl sulfate localized in the outer shell. Differential scanning calorimetry and X-ray diffraction results demonstrated that ACY, sodium dodecyl sulfate, and sucralose were well distributed in the PVP matrix in an amorphous state because of favorable second-order interactions. In vitro dissolution and permeation studies showed that the core-shell microparticle SDs rapidly freed ACY within 1 minute and promoted nearly eightfold increases in permeation rate across the sublingual mucosa compared with raw ACY powders.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015HESSD..12.2799T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015HESSD..12.2799T"><span>Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timms, W. A.; Crane, R.; Anderson, D. J.; Bouzalakos, S.; Whelan, M.; McGeeney, D.; Rahman, P. F.; Guinea, A.; Acworth, R. I.</p> <p>2015-03-01</p> <p>Evaluating the possibility of leakage through low permeability geological strata is critically important for sustainable water supplies, the extraction of fuels from strata such as coal beds, and the confinement of waste within the earth. The current work demonstrates that relatively rapid and reliable hydraulic conductivity (K) measurement of aquitard cores using accelerated gravity can inform and constrain larger scale assessments of hydraulic connectivity. Steady state fluid velocity through a low K porous sample is linearly related to accelerated gravity (g-level) in a centrifuge permeameter (CP) unless consolidation or geochemical reactions occur. The CP module was custom designed to fit a standard 2 m diameter geotechnical centrifuge (550 g maximum) with a capacity for sample dimensions of 30 to 100 mm diameter and 30 to 200 mm in length, and a maximum total stress of ~2 MPa at the base of the core. Formation fluids were used as influent to limit any shrink-swell phenomena which may alter the permeability. Vertical hydraulic conductivity (Kv) results from CP testing of cores from three sites within the same regional clayey silt formation varied (10-7 to 10-9 m s-1, n = 14). Results at one of these sites (1.1 × 10-10 to 3.5 × 10-9 m s-1, n = 5) that were obtained in < 24 h were similar to in situ Kv values (3 × 10-9 m s-1) from pore pressure responses over several weeks within a 30 m clayey sequence. Core scale and in situ Kv results were compared with vertical connectivity within a regional flow model, and considered in the context of heterogeneity and preferential flow paths at site and formation scale. More reliable assessments of leakage and solute transport though aquitards over multi-decadal timescales can be achieved by accelerated core testing together with advanced geostatistical and numerical methods.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA105808','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA105808"><span>Comparison of Viscous and Pressure Energy Exchange in Fluid Flow Induction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1981-06-01</p> <p>phases of the same fluid). 14 VSt PRIMARY JET NOZZLE HIGH VELOCITY CORE SUCT SECONFFARY FLUID FIGURE 1: A SIMPLE JET PUMP A.- ~is * II. BACKGROUND A...ratio. As the helix gets tighter, as from the twenty to thirty-five degree nozzles, the angular speed of the nozzle increases and the number of</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060041168&hterms=gravity+earth&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgravity%2Bearth','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060041168&hterms=gravity+earth&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgravity%2Bearth"><span>Satellite Gravity and the Geosphere: Contributions to the Study of the Solid Earth and Its Fluid Earth</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dickey, J. O.; Bentley, C. R.; Bilham, R.; Carton, J. A.; Eanes, R. J.; Herring, T. A.; Kaula, W. M.; Lagerloef, G. S. E.; Rojstaczer, S.; Smith, W. H. F.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20060041168'); toggleEditAbsImage('author_20060041168_show'); toggleEditAbsImage('author_20060041168_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20060041168_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20060041168_hide"></p> <p>1998-01-01</p> <p>The Earth is a dynamic system-it has a fluid, mobile atmosphere and oceans, a continually changing distribution of ice, snow, and groundwater, a fluid core undergoing hydromagnetic motion, a mantle undergoing both thermal convection and rebound from glacial loading of the last ice age, and mobile tectonic plates.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1350059-direct-observation-growth-au-pd-core-shell-nanoparticles-using-situ-low-dose-liquid-cell-stem-imaging','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1350059-direct-observation-growth-au-pd-core-shell-nanoparticles-using-situ-low-dose-liquid-cell-stem-imaging"><span>Direct Observation of the Growth of Au-Pd Core-Shell Nanoparticles Using in situ Low-Dose Liquid Cell STEM imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bhattarai, Nabraj; Prozorov, Tanya</p> <p>2016-07-25</p> <p>Bimetallic core-shell nanoparticles are widely used as catalysts in several industrial reactions, with core-shell structures permitting facile surface modification and allowing increased stability and durability, and cost-effectiveness of the catalysts. We report, for the first time, on observing the early stages of the formation of Au-Pd core-shell bimetallic nanoparticles via the seed-mediated growth in the presence of reducing agent, while employing the low-dose scanning transmission electron microscopy imaging with the fluid cell in situ. Use of the continuous flow in situ fluid cell platform allows for delivery of reagent solutions and generation of near-native reaction environment in the reaction chamber,more » and permits direct visualization of the early stages of formation of Au-Pd core-shell structures at low dose rate (0.1 e -/(Å 2s)) in the presence of ascorbic acid. No core-shell structures were detected in the absence of reducing agent at the electron dose of 32.6 e -/Å 2. While the core-shell structures formed in situ under the low-dose imaging closely resemble those obtained in solution synthesis, the reaction kinetics in the fluid cell is affected by the radiolysis of liquid reagents induced by electron beam, altering the rate-determining reaction steps. The enhanced reduction of Pd ions leads to initial rapid growth of the nascent Pd shell along the <111> direction at the Au interface, followed by a slower rearrangement of the outer Pd layer. The latter becomes the rate-determining step in the in situ reaction and appears to follow the oriented attachment-like movement to yield a remodeled, compact and stable Au-Pd core-shell nanostructure. Our findings highlight the differences between the two reaction pathways and aid in understanding the mechanism of formation of the core-shell nanostructure in situ.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996PhPl....3.4046B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996PhPl....3.4046B"><span>Toroidal gyrofluid equations for simulations of tokamak turbulence</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beer, M. A.; Hammett, G. W.</p> <p>1996-11-01</p> <p>A set of nonlinear gyrofluid equations for simulations of tokamak turbulence are derived by taking moments of the nonlinear toroidal gyrokinetic equation. The moment hierarchy is closed with approximations that model the kinetic effects of parallel Landau damping, toroidal drift resonances, and finite Larmor radius effects. These equations generalize the work of Dorland and Hammett [Phys. Fluids B 5, 812 (1993)] to toroidal geometry by including essential toroidal effects. The closures for phase mixing from toroidal ∇B and curvature drifts take the basic form presented in Waltz et al. [Phys. Fluids B 4, 3138 (1992)], but here a more rigorous procedure is used, including an extension to higher moments, which provides significantly improved accuracy. In addition, trapped ion effects and collisions are incorporated. This reduced set of nonlinear equations accurately models most of the physics considered important for ion dynamics in core tokamak turbulence, and is simple enough to be used in high resolution direct numerical simulations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNG21A0145R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNG21A0145R"><span>Increasing Helicity to Achieve a Dynamo State on the Three-Meter Model of the Earth's Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rojas, R.; Perevalov, A.; Lathrop, D. P.</p> <p>2017-12-01</p> <p>Dynamo theory describes the generation of magnetic fields in the flows of conducting fluids, for example, in stars and planetary cores. Spherical Couette flows, which are flows between two concentric and independently rotating spheres, is one of the experimental models for achieving this task in the laboratory. We have performed dynamo state search in our three-meter spherical-Couette model reaching up to Reynolds number near 108 with amplifications of the field between 10-30% but without a self-sustained dynamo magnetic field. A recent numerical work [K. Finke and A. Tilgner. Phys. Rev. E, 86:016310, Jul 2012] suggested that a roughened inner core reduces the threshold for dynamo action. The mean flow would have more poloidal component than the one we are generating with our current smooth sphere setup. With baffles flow would be expelled radially outward on the equatorial plane and returned at the poles, with opposite helicities in the two hemispheres. Baffles welded on our smooth inner sphere are proposed to achieve this task. We are working to perform experiments on a scaled water model of our experimental setup with Reynolds number near 105 to measure the helicity improvements of different baffle designs in support of upcoming Three-Meter modifications. We gratefully acknowledge support from NSF EAR-1417148.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70023707','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70023707"><span>Hydrothermal minerals and microstructures in the Silangkitang geothermal field along the Great Sumatran fault zone, Sumatra, Indonesia</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Moore, Diane E.; Hickman, S.; Lockner, D.A.; Dobson, P.F.</p> <p>2001-01-01</p> <p>Detailed study of core samples of silicic tuff recovered from three geothermal wells along the strike-slip Great Sumatran fault zone near Silangkitang, North Sumatra, supports a model for enhanced hydrothermal circulation adjacent to this major plate-boundary fault. Two wells (A and C) were drilled nearly vertically ??1 km southwest of the eastern (i.e., the principal) fault trace, and the third, directional well (B) was drilled eastward from the site of well A to within ??100 m of the principal fault trace. The examined core samples come from depths of 1650-2120 m at measured well temperatures of 180-320 ??C. The samples collected near the principal fault trace have the highest temperatures, the largest amount of secondary pore space that correlates with high secondary permeability, and the most extensive hydrothermal mineral development. Secondary permeability and the degree of hydrothermal alteration decrease toward the southwestern margin of the fault zone. These features indicate episodic, localized flow of hot, possibly CO2-rich fluids within the fault zone. The microstructure populations identified in the core samples correlate to the subsidiary fault patterns typical of strike-slip faults. The geothermal reservoir appears to be centered on the fault zone, with the principal fault strands and adjoining, highly fractured and hydrothermally altered rock serving as the main conduits for vertical fluid flow and advective heat transport from deeper magmatic sources.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhyA..391.4427B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhyA..391.4427B"><span>Critical parameters of hard-core Yukawa fluids within the structural theory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bahaa Khedr, M.; Osman, S. M.</p> <p>2012-10-01</p> <p>A purely statistical mechanical approach is proposed to account for the liquid-vapor critical point based on the mean density approximation (MDA) of the direct correlation function. The application to hard-core Yukawa (HCY) fluids facilitates the use of the series mean spherical approximation (SMSA). The location of the critical parameters for HCY fluid with variable intermolecular range is accurately calculated. Good agreement is observed with computer simulation results and with the inverse temperature expansion (ITE) predictions. The influence of the potential range on the critical parameters is demonstrated and the universality of the critical compressibility ratio is discussed. The behavior of the isochoric and isobaric heat capacities along the equilibrium line and the near vicinity of the critical point is discussed in details.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016919','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016919"><span>Fluid inclusions and preliminary studies of hydrothermal alteration in core hole PLTG-1, Platanares geothermal area, Honduras</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bargar, K.E.</p> <p>1991-01-01</p> <p>The Platanares geothermal area in western Honduras consists of more than 100 hot springs that issue from numerous hot-spring groups along the banks or within the streambed of the Quebrada de Agua Caliente (brook of hot water). Evaluation of this geothermal area included drilling a 650-m deep PLTG-1 drill hole which penetrated a surface mantling of stream terrace deposits, about 550 m of Tertiary andesitic lava flows, and Cretaceous to lower Tertiary sedimentary rocks in the lower 90 m of the drill core. Fractures and cavities in the drill core are partly to completely filled by hydrothermal minerals that include quartz, kaolinite, mixed-layer illite-smectite, barite, fluorite, chlorite, calcite, laumontite, biotite, hematite, marcasite, pyrite, arsenopyrite, stibnite, and sphalerite; the most common open-space fillings are calcite and quartz. Biotite from 138.9-m depth, dated at 37.41 Ma by replicate 40Ar/39 Ar analyses using a continuous laser system, is the earliest hydrothermal mineral deposited in the PLTG-1 drill core. This mid-Tertiary age indicates that at least some of the hydrothermal alteration encountered in the PLTG-1 drill core occured in the distant past and is unrelated to the present geothermal system. Furthermore, homogenization temperatures (Th) and melting-point temperatures (Tm) for fluid inclusions in two of the later-formed hydrothermal minerals, calcite and barite, suggest that the temperatures and concentration of dissolved solids of the fluids present at the time these fluid inclusions formed were very different from the present temperatures and fluid chemistry measured in the drill hole. Liquid-rich secondary fluid inclusions in barite and caicite from drill hole PLTG-1 have Th values that range from about 20??C less than the present measured temperature curve at 590.1-m depth to as much as 90??C higher than the temperature curve at 46.75-m depth. Many of the barite Th measurements (ranging between 114?? and 265??C) plot above the reference surface boiling-point curve for pure water assuming hydrostatic conditions; however, the absence of evidence for boiling in the fluid inclusions indicates that at the time the minerals formed, the ground surface must have been at least 80 m higher than at present and underwent stream erosion to the current elevation. Near-surface mixed-layer illite-smectite is closely associated with barite and appears to have formed at about the same temperature range (about 120?? to 200??C) as the fluid-inclusion Th values for barite. Fluid-inclusion Th values for calcite range between about 136?? and 213??C. Several of the calcite Th values are significantly lower than the present measured temperature curve. The melting-point temperatures (Tm) of fluid-inclusion ice yield calculated salinities, ranging from near zero to as much as 5.4 wt. % NaCl equivalent, which suggest that much of the barite and calcite precipitated from fluids of significantly greater salinity than the present low salinity Platanares hot-spring water or water produced from the drill hole. ?? 1991.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP23B1310P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP23B1310P"><span>Clear as Mud: Changes in Paleoshelf Environments and Deposition Rates at Medford, New Jersey during the Paleocene-Eocene Thermal Maximum</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Podrecca, L.; Miller, K. G.; Wright, J. D.; Browning, J. V.; Emge, T.</p> <p>2017-12-01</p> <p>The Paleocene-Eocene boundary marks a time of swift global climatic change. Constraining the timeframe of this event is a first order question necessary for ascertaining the origin of the event and the potential for its use as an analog for modern climate change. The New Jersey shelf sediments of the Marlboro Formation records this time period with exceptionally thick (5-15m) records of the period of global low carbon isotopic values ("the core") which requires minimum sedimentation rates of 10's cm/kyr. Rhythmic layers have been previously reported from Wilson Lake & Millville, NJ (IODP Leg 174AX). These structures coined "laminae couplets" consist of semi-periodic 1-2mm thick raised laminations separated by matrix of varying width (averaging 1.8cm). These have been dismissed as artifacts of drilling "biscuits". We report here on a series of shallow auger cores drilled on a transect at Medford, NJ, without using drilling fluid. These cores also show a similar set of structures on the 2cm scale verifying that they are primary depositional features. The mm width laminae in the auger core show remarkable swelling within minutes of splitting. XRD, XRF, bulk carbonate geochemistry, and grain size analysis have been determined at regular depth intervals throughout the core. We have analyzed differences in these parameters between the laminae and interbedded matrix material, as well as across the transect as a whole. In general, the Marlboro formation at this updip location consists of micaceous, lignitic, very clayey silt (mean size 6 micrometers) with occasional organic debris indicating proximal deposition from a fluvial system. Paleodepth of 40m and normal marine salinities are estimated using a paleoslope model and the presence of common though not abundant planktonic foraminifera. We discuss a model of deposition for the Marlboro Formation as fluid mud (nearbed suspension flows) associated with the "Appalachian Amazon" alluding toward the finer grained inter-laminae representing settling events. These may be either hemipelagics associated with episodic flood events or seasonal periods of in-river sediment discharge and the benthic salinity front.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A11J..07U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A11J..07U"><span>MCore: A High-Order Finite-Volume Dynamical Core for Atmospheric General Circulation Models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ullrich, P.; Jablonowski, C.</p> <p>2011-12-01</p> <p>The desire for increasingly accurate predictions of the atmosphere has driven numerical models to smaller and smaller resolutions, while simultaneously exponentially driving up the cost of existing numerical models. Even with the modern rapid advancement of computational performance, it is estimated that it will take more than twenty years before existing models approach the scales needed to resolve atmospheric convection. However, smarter numerical methods may allow us to glimpse the types of results we would expect from these fine-scale simulations while only requiring a fraction of the computational cost. The next generation of atmospheric models will likely need to rely on both high-order accuracy and adaptive mesh refinement in order to properly capture features of interest. We present our ongoing research on developing a set of ``smart'' numerical methods for simulating the global non-hydrostatic fluid equations which govern atmospheric motions. We have harnessed a high-order finite-volume based approach in developing an atmospheric dynamical core on the cubed-sphere. This type of method is desirable for applications involving adaptive grids, since it has been shown that spuriously reflected wave modes are intrinsically damped out under this approach. The model further makes use of an implicit-explicit Runge-Kutta-Rosenbrock (IMEX-RKR) time integrator for accurate and efficient coupling of the horizontal and vertical model components. We survey the algorithmic development of the model and present results from idealized dynamical core test cases, as well as give a glimpse at future work with our model.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70014507','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70014507"><span>Fluid inclusion from drill hole DW-5, Hohi geothermal area, Japan: Evidence of boiling and procedure for estimating CO2 content</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sasada, M.; Roedder, E.; Belkin, H.E.</p> <p>1986-01-01</p> <p>Fluid inclusion studies have been used to derive a model for fluid evolution in the Hohi geothermal area, Japan. Six types of fluid inclusions are found in quartz obtained from the drill core of DW-5 hole. They are: (I) primary liquid-rich with evidence of boiling; (II) primary liquid-rich without evidence of boiling; (III) primary vapor-rich (assumed to have been formed by boiling); (IV) secondary liquid-rich with evidence of boiling; (V) secondary liquid-rich without evidence of boiling; (VI) secondary vapor-rich (assumed to have been formed by boiling). Homogenization temperatures (Th) range between 196 and 347??C and the final melting point of ice (Tm) between -0.2 and -4.3??C. The CO2 content was estimated semiquantitatively to be between 0 and 0.39 wt. % based on the bubble behavior on crushing. NaCl equivalent solid solute salinity of fluid inclusions was determined as being between 0 and 6.8 wt. % after minor correction for CO2 content. Fluid inclusions in quartz provide a record of geothermal activity of early boiling and later cooling. The CO2 contents and homogenization temperatures of fluid inclusions with evidence of boiling generally increase with depth; these changes, and NaCl equivalent solid solute salinity of the fluid can be explained by an adiabatic boiling model for a CO2-bearing low-salinity fluid. Some high-salinity inclusions without CO2 are presumed to have formed by a local boiling process due to a temperature increase or a pressure decrease. The liquid-rich primary and secondary inclusions without evidence of boiling formed during the cooling process. The salinity and CO2 content of these inclusions are lower than those in the boiling fluid at the early stage, probably as a result of admixture with groundwater. ?? 1986.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1183943','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1183943"><span>Method for the production of fabricated hollow microspheroids</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wickramanayake, Shan; Luebke, David R.</p> <p>2015-06-09</p> <p>The method relates to the fabrication of a polymer microspheres comprised of an asymmetric layer surrounding a hollow interior. The fabricated hollow microsphere is generated from a nascent hollow microsphere comprised of an inner core of core fluid surrounded by a dope layer of polymer dope, where the thickness of the dope layer is at least 10% and less than 50% of the diameter of the inner core. The nascent hollow microsphere is exposed to a gaseous environment, generating a vitrified hollow microsphere, which is subsequently immersed in a coagulation bath. Solvent exchange produces a fabricated hollow microsphere comprised of a densified outer skin surrounding a macroporous inner layer, which surrounds a hollow interior. In an embodiment, the polymer is a polyimide or a polyamide-imide, and the non-solvent in the core fluid and the coagulation bath is water. The fabricated hollow microspheres are particularly suited as solvent supports for gas separation processes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21643070','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21643070"><span>Optofluidic refractive-index sensor in step-index fiber with parallel hollow micro-channel.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, H W; Schmidt, M A; Uebel, P; Tyagi, H; Joly, N Y; Scharrer, M; Russell, P St J</p> <p>2011-04-25</p> <p>We present a simple refractive index sensor based on a step-index fiber with a hollow micro-channel running parallel to its core. This channel becomes waveguiding when filled with a liquid of index greater than silica, causing sharp dips to appear in the transmission spectrum at wavelengths where the glass-core mode phase-matches to a mode of the liquid-core. The sensitivity of the dip-wavelengths to changes in liquid refractive index is quantified and the results used to study the dynamic flow characteristics of fluids in narrow channels. Potential applications of this fiber microstructure include measuring the optical properties of liquids, refractive index sensing, biophotonics and studies of fluid dynamics on the nanoscale.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26509578','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26509578"><span>Transport Mechanisms and Quality Changes During Frying of Chicken Nuggets--Hybrid Mixture Theory Based Modeling and Experimental Verification.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bansal, Harkirat S; Takhar, Pawan S; Alvarado, Christine Z; Thompson, Leslie D</p> <p>2015-12-01</p> <p>Hybrid mixture theory (HMT) based 2-scale fluid transport relations of Takhar coupled with a multiphase heat transfer equation were solved to model water, oil and gas movement during frying of chicken nuggets. A chicken nugget was treated as a heterogeneous material consisting of meat core with wheat-based coating. The coupled heat and fluid transfer equations were solved using the finite element method. Numerical simulations resulted in data on spatial and temporal profiles for moisture, rate of evaporation, temperature, oil, pore pressure, pressure in various phases, and coefficient of elasticity. Results showed that most of the oil stayed in the outer 1.5 mm of the coating region. Temperature values greater than 100 °C were observed in the coating after 30 s of frying. Negative gage-pore pressure (p(w) < p(g)) magnitudes were observed in simulations, which is in agreement with experimental observations of Sandhu and others. It is hypothesized that high water-phase capillary pressure (p(c) > p(g)) in the hydrophilic matrix causes p(w) < p(g), which further results in negative pore pressure. The coefficient of elasticity was the highest at the surface (2.5 × 10(5) Pa) for coating and the interface of coating and core (6 × 10(5) Pa). Kinetics equation for color change obtained from experiments was coupled with the HMT based model to predict the color (L, a, and b) as a function of frying time. © 2015 Institute of Food Technologists®</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DFD.GR004P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DFD.GR004P"><span>Scaling in two-fluid pinch-off</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pommer, Chris; Harris, Michael; Basaran, Osman</p> <p>2010-11-01</p> <p>The physics of two-fluid pinch-off, which arises whenever drops, bubbles, or jets of one fluid are ejected from a nozzle into another fluid, is scientifically important and technologically relevant. While the breakup of a drop in a passive environment is well understood, the physics of pinch-off when both the inner and outer fluids are dynamically active remains inadequately understood. Here, the breakup of a compound jet whose core and shell are incompressible Newtonian fluids is analyzed computationally when the interior is a "bubble" and the exterior is a liquid. The numerical method employed is an implicit method of lines ALE algorithm which uses finite elements with elliptic mesh generation and adaptive finite differences for time integration. Thus, the new approach neither starts with a priori idealizations, as has been the case with previous computations, nor is limited to length scales above that set by the wavelength of visible light as in any experimental study. In particular, three distinct responses are identified as the ratio m of the outer fluid's viscosity to the inner fluid's viscosity is varied. For small m, simulations show that the minimum neck radius r initially scales with time τ before breakup as r ˜0.58° (in accord with previous experiments and inviscid fluid models) but that r ˜τ once r becomes sufficiently small. For intermediate and large values of m, r ˜&αcirc;, where the exponent α may not equal one, once again as r becomes sufficiently small.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H23B1237C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H23B1237C"><span>Porosity and Permeability Evolution in Cemented Rock Cores under Reactive Flowing Conditions: Comparative Analysis between Limestone and Sandstone Host Rocks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, P.; Karpyn, Z.; Li, L.</p> <p>2013-12-01</p> <p>CO2-brine has the potential to alter wellbore cement in depleted oil and gas reservoirs under geological CO2 sequestration conditions. A better understanding of CO2-brine-cement-rock interaction is needed to evaluate the seal integrity of candidate sequestration formation in the long run. This work investigates possible alteration of wellbore cement when bonded by different host formation rock upon exposure to CO2-saturated brine. Composite cement-sandstone and cement-limestone core samples were created to perform reactive coreflood experiments. After an eight-day dynamic flow-through period, both cores had a similar extent of porosity increase, while the cement-limestone core experienced a ten-fold higher increase in permeability. With the aid of X-ray Micro-CT imaging and Scanning Electron Microscopy, it is observed that cement underwent greater degradation at the cement-sandstone interface. Degradation of cement-limestone core mainly took place on the host rock matrix. Worm holes were developed and a solution channel was formed in the limestone, creating a dominant flow path that altered both flow and reaction behavior. Limestone buffered the injected acidic brine preventing further deterioration of cement near the core outlet. Changes in fluid chemistry of limestone and sandstone coreflood effluents are compared. Results from this work are aimed at assisting the development and validation of robust reactive transport models through direct measurement of cemented rock core porosity and permeability evolution as well as the effluent aqueous chemistry change. This will subsequently improve predictive capabilities of reactive transport models associated with CO2 sequestration in geologic environments. Permeability Evolution of Cement-Rock Core Sample during Dynamic Flow of CO2-Brine</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017140','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017140"><span>The change in orientation of subsidiary shears near faults containing pore fluid under high pressure</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Byerlee, J.</p> <p>1992-01-01</p> <p>Byerlee, J., 1992. The change in orientation of subsidiary shears near faults containing pore fluid under high pressure. In: T. Mikumo, K. Aki, M. Ohnaka, L.J. Ruff and P.K.P. Spudich (Editors), Earthquake Source Physics and Earthquake Precursors. Tectonophysics, 211: 295-303. The mechanical effects of a fault containing near-lithostatic fluid pressure in which fluid pressure decreases monotonically from the core of the fault zone to the adjacent country rock is considered. This fluid pressure distribution has mechanical implications for the orientation of subsidiary shears around a fault. Analysis shows that the maximum principal stress is oriented at a high angle to the fault in the country rock where the pore pressure is hydrostatic, and rotates to 45?? to the fault within the fault zone where the pore pressure is much higher. This analysis suggests that on the San Andreas fault, where heat flow constraints require that the coefficient of friction for slip on the fault be less than 0.1, the pore fluid pressure on the main fault is 85% of the lithostatic pressure. The observed geometry of the subsidiary shears in the creeping section of the San Andreas are broadly consistent with this model, with differences that may be due to the heterogeneous nature of the fault. ?? 1992.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS53D1236W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS53D1236W"><span>Systematics of Alkali Metals in Pore Fluids from Serpentinite Mud Volcanoes: IODP Expedition 366</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wheat, C. G.; Ryan, J.; Menzies, C. D.; Price, R. E.; Sissmann, O.</p> <p>2017-12-01</p> <p>IODP Expedition 366 focused, in part, on the study of geochemical cycling, matrix alteration, material and fluid transport, and deep biosphere processes within the subduction channel in the Mariana forearc. This was accomplished through integrated sampling of summit and flank regions of three active serpentinite mud volcanoes (Yinazao (Blue Moon), Asùt Tesoro (Big Blue), and Fantangisña (Celestial) Seamounts). These edifices present a transect of depths to the Pacific Plate, allowing one to characterize thermal, pressure and compositional effects on processes that are associated with the formation of serpentinite mud volcanoes and continued activity below and within them. Previous coring on ODP Legs 125 and 195 at two other serpentinite mud volcanoes (Conical and South Chamorro Seamounts) and piston, gravity, and push cores from several other Mariana serpentinite mud volcanoes add to this transect of sites where deep-sourced material is discharged at the seafloor. Pore waters (149 samples) were squeezed from serpentinite materials to determine the composition of deep-sourced fluid and to assess the character, extent, and effect of diagenetic reactions and mixing with seawater on the flanks of the seamounts as the serpentinite matrix weathers. In addition two Water Sampler Temperature Tool (WSTP) fluid samples were collected within two of the cased boreholes, each with at least 30 m of screened casing that allows formations fluids to discharge into the borehole. Shipboard results for Na and K record marked seamount-to-seamount differences in upwelling summit fluids, and complex systematics in fluids obtained from flank sites. Here we report new shore-based Rb and Cs measurements, two elements that have been used to constrain the temperature of the deep-sourced fluid. Data are consistent with earlier coring and drilling expeditions, resulting in systematic changes with depth (and by inference temperature) to the subduction channel.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27500742','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27500742"><span>Fast imaging of laboratory core floods using 3D compressed sensing RARE MRI.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ramskill, N P; Bush, I; Sederman, A J; Mantle, M D; Benning, M; Anger, B C; Appel, M; Gladden, L F</p> <p>2016-09-01</p> <p>Three-dimensional (3D) imaging of the fluid distributions within the rock is essential to enable the unambiguous interpretation of core flooding data. Magnetic resonance imaging (MRI) has been widely used to image fluid saturation in rock cores; however, conventional acquisition strategies are typically too slow to capture the dynamic nature of the displacement processes that are of interest. Using Compressed Sensing (CS), it is possible to reconstruct a near-perfect image from significantly fewer measurements than was previously thought necessary, and this can result in a significant reduction in the image acquisition times. In the present study, a method using the Rapid Acquisition with Relaxation Enhancement (RARE) pulse sequence with CS to provide 3D images of the fluid saturation in rock core samples during laboratory core floods is demonstrated. An objective method using image quality metrics for the determination of the most suitable regularisation functional to be used in the CS reconstructions is reported. It is shown that for the present application, Total Variation outperforms the Haar and Daubechies3 wavelet families in terms of the agreement of their respective CS reconstructions with a fully-sampled reference image. Using the CS-RARE approach, 3D images of the fluid saturation in the rock core have been acquired in 16min. The CS-RARE technique has been applied to image the residual water saturation in the rock during a water-water displacement core flood. With a flow rate corresponding to an interstitial velocity of vi=1.89±0.03ftday(-1), 0.1 pore volumes were injected over the course of each image acquisition, a four-fold reduction when compared to a fully-sampled RARE acquisition. Finally, the 3D CS-RARE technique has been used to image the drainage of dodecane into the water-saturated rock in which the dynamics of the coalescence of discrete clusters of the non-wetting phase are clearly observed. The enhancement in the temporal resolution that has been achieved using the CS-RARE approach enables dynamic transport processes pertinent to laboratory core floods to be investigated in 3D on a time-scale and with a spatial resolution that, until now, has not been possible. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12780100','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12780100"><span>Long-lived planetary vortices and their evolution: Conservative intermediate geostrophic model.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sutyrin, Georgi G.</p> <p>1994-06-01</p> <p>Large, long-lived vortices, surviving during many turnaround times and far longer than the dispersive linear Rossby wave packets, are abundant in planetary atmospheres and oceans. Nonlinear effects which prevent dispersive decay of intense cyclones and anticyclones and provide their self-propelling propagation are revised here using shallow water equations and their balanced approximations. The main physical mechanism allowing vortical structures to be long-lived in planetary fluid is the quick fluid rotation inside their cores which prevents growth in the amplitude of asymmetric circulation arising due to the beta-effect. Intense vortices of both signs survive essentially longer than the linear Rossby wave packet if their azimuthal velocity is much larger than the Rossby wave speed. However, in the long-time evolution, cyclonic and anticyclonic vortices behave essentially differently that is illustrated by the conservative intermediate geostrophic model. Asymmetric circulation governing vortex propagation is described by the azimuthal mode m=1 for the initial value problem as well as for steadily propagating solutions. Cyclonic vortices move west-poleward decaying gradually due to Rossby wave radiation while anticyclonic ones adjust to non-radiating solitary vortices. Slow weakening of an intense cyclone with decreasing of its size and shrinking of the core is described assuming zero azimuthal velocity outside the core while drifting poleward. The poleward tendency of the cyclone motion relative to the stirring flow corresponds to characteristic trajectories of tropical cyclones in the Earth's atmosphere. The asymmetry in dispersion-nonlinear properties of cyclones and anticyclones is thought to be one of the essential reasons for the observed predominance of anticyclones among long-lived vortices in the atmospheres of the giant planets and also among intrathermoclinic eddies in the ocean.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020073237','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020073237"><span>Experimental Study of the Richtmyer-Meshkov Instability of Incompressible Fluids</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Niederhaus, Charles; Jacobs, Jeffrey W.</p> <p>2002-01-01</p> <p>The Richtmyer-Meshkov instability of a low Atwood number, miscible, two-liquid system is investigated experimentally. The initially stratified fluids are contained within a rectangular tank mounted to a sled that rides on a vertical set of rails. The instability is generated by dropping the sled onto a coil spring, producing a nearly impulsive upward acceleration. The subsequent freefall that occurs as the container travels upward and then downward on the rails allows the instability to evolve in the absence of gravity. The interface separating the two liquids initially has a well-defined, sinusoidal perturbation that quickly inverts and then grows in amplitude after undergoing the impulsive acceleration. Disturbance amplitudes are measured and compared to theoretical predictions. Linear stability theory gives excellent agreement with the measured initial growth rate, a(sub 0), for single-mode perturbations with the predicted amplitudes differing by less than 10% from experimental measurements up to a nondimensional time ka(sub 0)t = 0.7, where k is the wavenumber. Linear stability theory also provides excellent agreement for the individual mode amplitudes of multi-mode initial perturbations up until the interface becomes multi-valued. Comparison with previously published weakly nonlinear single-mode models shows good agreement up to ka(sub 0)t = 3, while published nonlinear single-mode models provide good agreement up to ka(sub 0)t = 30. The effects of Reynolds number on the vortex core evolution and overall growth rate of the interface are also investigated. Measurements of the overall amplitude are found to be unaffected by the Reynolds number for the range of values studied here. However, experiments carried out at lower values of Reynolds numbers were found to have decreased vortex core rotation rates. In addition, an instability in the vortex cores is observed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17183319','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17183319"><span>A deep dynamo generating Mercury's magnetic field.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Christensen, Ulrich R</p> <p>2006-12-21</p> <p>Mercury has a global magnetic field of internal origin and it is thought that a dynamo operating in the fluid part of Mercury's large iron core is the most probable cause. However, the low intensity of Mercury's magnetic field--about 1% the strength of the Earth's field--cannot be reconciled with an Earth-like dynamo. With the common assumption that Coriolis and Lorentz forces balance in planetary dynamos, a field thirty times stronger is expected. Here I present a numerical model of a dynamo driven by thermo-compositional convection associated with inner core solidification. The thermal gradient at the core-mantle boundary is subadiabatic, and hence the outer region of the liquid core is stably stratified with the dynamo operating only at depth, where a strong field is generated. Because of the planet's slow rotation the resulting magnetic field is dominated by small-scale components that fluctuate rapidly with time. The dynamo field diffuses through the stable conducting region, where rapidly varying parts are strongly attenuated by the skin effect, while the slowly varying dipole and quadrupole components pass to some degree. The model explains the observed structure and strength of Mercury's surface magnetic field and makes predictions that are testable with space missions both presently flying and planned.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29935514','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29935514"><span>Study of the hard-disk system at high densities: the fluid-hexatic phase transition.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mier-Y-Terán, Luis; Machorro-Martínez, Brian Ignacio; Chapela, Gustavo A; Del Río, Fernando</p> <p>2018-06-21</p> <p>Integral equations of uniform fluids have been considered unable to predict any characteristic feature of the fluid-solid phase transition, including the shoulder that arises in the second peak of the fluid-phase radial distribution function, RDF, of hard-core systems obtained by computer simulations, at fluid densities very close to the structural two-step phase transition. This reasoning is based on the results of traditional integral approximations, like Percus-Yevick, PY, which does not show such a shoulder in hard-core systems, neither in two nor three dimensions. In this work, we present results of three Ansätze, based on the PY theory, that were proposed to remedy the lack of PY analytical solutions in two dimensions. This comparative study shows that one of those Ansätze does develop a shoulder in the second peak of the RDF at densities very close to the phase transition, qualitatively describing this feature. Since the shoulder grows into a peak at still higher densities, this integral equation approach predicts the appearance of an orientational order characteristic of the hexatic phase in a continuous fluid-hexatic phase transition.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.P13B1754M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.P13B1754M"><span>Radius of lunar core estimated by GRAIL results</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsumoto, K.; Yamada, R.; Kikuchi, F.; Iwata, T.; Hanada, H.; Ishihara, Y.; Kamata, S.; Sasaki, S.</p> <p>2013-12-01</p> <p>Internal structure and composition of the Moon provide important clue and constraints on theories for how the Moon formed and evolved. The Apollo seismic network has contributed to the internal structure modeling. Efforts have been made to detect the lunar core from the noisy Apollo data (e.g., [1], [2]), but there is scant information about the structure below the deepest moonquakes at about 1000 km depth. On the other hand, there have been geodetic studies to infer the deep structure of the Moon. For example, LLR (Lunar Laser Ranging) data analyses detected a displacement of the lunar pole of rotation, indicating that dissipation is acting on the rotation arising from a fluid core [3]. Bayesian inversion using geodetic data (such as mass, moments of inertia, tidal Love numbers k2 and h2, and quality factor Q) also suggests a fluid core and partial melt in the lower mantle region [4]. Recent analyses of GRAIL data have achieved the improved k2 accuracy; JPL solution is 0.02405 × 0.00018 [5], and GSFC solution is 0.02427 × 0.00026 [6]. The two solutions are consistent with each other within their error bounds, and the accuracy of k2 is now about 1 %. Such an accurately-determined Love number will contribute to constrain the structure of the lunar deep interior, such as the radius of the possible liquid core. We used geodetic data of the mass, the mean moment of inertia, the Love numbers h2 and k2 to infer the size of liquid core. It is difficult to tightly constrain the internal structure from the geodetic data only because there are trade-offs among the structures of crust, mantle, and core. In our preliminary analysis we used a 5-layer model and the mantle structure was constrained by VPREMOON [2] with 5 % error for density and 10 % error for shear and bulk moduli being assumed. An inversion using Markov chain Monte Carlo method indicates that the core radius is 480 × 50 km, but the density values were sampled around the assumed lower limit of 3600 kg/m3. When the lower limit of the core density is raised to 5000 kg/m3, the estimated core radius gets smaller to be 380 × 50 km. A better estimate of the core parameters is expected by including Apollo seismic data into the analysis. References [1] Weber et al. (2011), Science, 331, 309-312, doi:10.1126/science.1199375 [2] Garcia et al. (2011), PEPI, doi:10.1016/j.pepi.2011.06.015 [3] Williams et al. (2001), JGR, 106, E11, 27,933-27,968 [4] Khan and Mosegaard (2005), GRL, 32, L22203, doi:10.1029/2005GL023985 [5] Konopliv et al (2013), JGR, 118, doi:10.1002/jgre.20097 [6] Taken from the PDS label of GRAIL Derived Data Products</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/7160256','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/7160256"><span>Emergency cooling system and method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Oosterkamp, W.J.; Cheung, Y.K.</p> <p>1994-01-04</p> <p>An improved emergency cooling system and method are disclosed that may be adapted for incorporation into or use with a nuclear BWR wherein a reactor pressure vessel (RPV) containing a nuclear core and a heat transfer fluid for circulation in a heat transfer relationship with the core is housed within an annular sealed drywell and is fluid communicable therewith for passage thereto in an emergency situation the heat transfer fluid in a gaseous phase and any noncondensibles present in the RPV, an annular sealed wetwell houses the drywell, and a pressure suppression pool of liquid is disposed in the wetwell and is connected to the drywell by submerged vents. The improved emergency cooling system and method has a containment condenser for receiving condensible heat transfer fluid in a gaseous phase and noncondensibles for condensing at least a portion of the heat transfer fluid. The containment condenser has an inlet in fluid communication with the drywell for receiving heat transfer fluid and noncondensibles, a first outlet in fluid communication with the RPV for the return to the RPV of the condensed portion of the heat transfer fluid and a second outlet in fluid communication with the drywell for passage of the noncondensed balance of the heat transfer fluid and the noncondensibles. The noncondensed balance of the heat transfer fluid and the noncondensibles passed to the drywell from the containment condenser are mixed with the heat transfer fluid and the noncondensibles from the RPV for passage into the containment condenser. A water pool is provided in heat transfer relationship with the containment condenser and is thermally communicable in an emergency situation with an environment outside of the drywell and the wetwell for conducting heat transferred from the containment condenser away from the wetwell and the drywell. 5 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712627D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712627D"><span>Experimental investigations and geochemical modelling of site-specific fluid-fluid and fluid-rock interactions in underground storage of CO2/H2/CH4 mixtures: the H2STORE project</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Lucia, Marco; Pilz, Peter</p> <p>2015-04-01</p> <p>Underground gas storage is increasingly regarded as a technically viable option for meeting the energy demand and environmental targets of many industrialized countries. Besides the long-term CO2 sequestration, energy can be chemically stored in form of CO2/CH4/H2 mixtures, for example resulting from excess wind energy. A precise estimation of the impact of such gas mixtures on the mineralogical, geochemical and petrophysical properties of specific reservoirs and caprocks is crucial for site selection and optimization of storage depth. Underground gas storage is increasingly regarded as a technically viable option for meeting environmental targets and the energy demand through storage in form of H2 or CH4, i.e. resulting from excess wind energy. Gas storage in salt caverns is nowadays a mature technology; in regions where favorable geologic structures such as salt diapires are not available, however, gas storage can only be implemented in porous media such as depleted gas and oil reservoirs or suitable saline aquifers. In such settings, a significant amount of in-situ gas components such as CO2, CH4 (and N2) will always be present, making the CO2/CH4/H2 system of particular interest. A precise estimation of the impact of their gas mixtures on the mineralogical, geochemical and petrophysical properties of specific reservoirs and caprocks is therefore crucial for site selection and optimization of storage depth. In the framework of the collaborative research project H2STORE, the feasibility of industrial-scale gas storage in porous media in several potential siliciclastic depleted gas and oil reservoirs or suitable saline aquifers is being investigated by means of experiments and modelling on actual core materials from the evaluated sites. Among them are the Altmark depleted gas reservoir in Saxony-Anhalt and the Ketzin pilot site for CO2 storage in Brandenburg (Germany). Further sites are located in the Molasse basin in South Germany and Austria. In particular, two work packages hosted at the German Research Centre for Geosciences (GFZ) focus on the fluid-fluid and fluid-rock interactions triggered by CO2, H2 and their mixtures. Laboratory experiments expose core samples to hydrogen and CO2/hydrogen mixtures under site-specific conditions (temperatures up to 200 °C and pressure up to 300 bar). The resulting qualitative and, whereas possible, quantitative data are expected to ameliorate the precision of predictive geochemical and reactive transport modelling, which is also performed within the project. The combination of experiments, chemical and mineralogical analyses and models is needed to improve the knowledge about: (1) solubility model and mixing rule for multicomponent gas mixtures in high saline formation fluids: no data are namely available in literature for H2-charged gas mixtures in the conditions expected in the potential sites; (2) chemical reactivity of different mineral assemblages and formation fluids in a broad spectrum of P-T conditions and composition of the stored gas mixtures; (3) thermodynamics and kinetics of relevant reactions involving mineral dissolution or precipitation. The resulting amelioration of site characterization and the overall enhancement in understanding the potential processes will benefit the operational reliability, the ecological tolerance, and the economic efficiency of future energy storing plants, crucial aspects for public acceptance and for industrial investors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730037391&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dearths%2Bouter%2Bcore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730037391&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dearths%2Bouter%2Bcore"><span>The core paradox.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kennedy, G. C.; Higgins, G. H.</p> <p>1973-01-01</p> <p>Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002821','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002821"><span>Modeling of Supersonic Film Cooling on the J-2X Nozzle Extension</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ruf, Joseph H.; Morris, Christopher I.</p> <p>2011-01-01</p> <p>Supersonic film cooling (SSFC) of nozzles has been used in several liquid rocket engine designs, and is being applied to the nozzle extension (NE) of the J-2X upper stage engine currently under development. Turbine exhaust gas (TEG) is injected tangentially from a manifold along the NE, and provides a thermal barrier from the core nozzle flow for the NE. As the TEG stream mixes with the nozzle flow, the effectiveness of the thermal barrier is reduced. This paper documents computational fluid dynamics (CFD) analysis work performed by NASA Marshall Space Flight Center (MSFC) to model the flow of the TEG through the manifold, into the nozzle, and the subsequent mixing of the TEG stream with the core flow. The geometry and grid of the TEG manifold, structural support ribs, and the NE wall will be shown, and the CFD boundary conditions described. The Loci-CHEM CFD code used in this work will also be briefly described. A unique approach to modeling the combined TEG manifold/thrust chamber assembly (TCA) was employed, as it was not practical to model the entire 360 circumferential range in one simulation. Prior CFD validation work modeling Calspan SSFC experiments in the early 1990s, documented in a previous AIAA paper, will also be briefly discussed. The fluid dynamics of the TEG flow through the manifold, into and between the structural support ribs, and into the nozzlette that feeds the TCA will be described. Significant swirl and non-uniformities are present, which along with the wakes from the ribs, act to degrade the film cooling effectiveness compared to idealized injection of TEG gas. The effect of these flow characteristics on the adiabatic wall temperature profile on the NE will be discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/879713','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/879713"><span>Heat Exchanger With Internal Pin Elements</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gerstmann, Joseph; Hannon, Charles L.</p> <p>2004-01-13</p> <p>A heat exchanger/heater comprising a tubular member having a fluid inlet end, a fluid outlet end and plurality of pins secured to the interior wall of the tube. Various embodiments additionally comprise a blocking member disposed concentrically inside the pins, such as a core plug or a baffle array. Also disclosed is a vapor generator employing an internally pinned tube, and a fluid-heater/heat-exchanger utilizing an outer jacket tube and fluid-side baffle elements, as well as methods for heating a fluid using an internally pinned tube.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H21P..08F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H21P..08F"><span>Characterizing Mobile/Less-Mobile Porosity and Solute Exchange in Dual-Domain Media Using Tracer Experiments and Electrical Measurements in a Hassler-Type Core Holder</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Falzone, S.; Slater, L. D.; Day-Lewis, F. D.; Parker, B. L.; Keating, K.; Robinson, J.</p> <p>2017-12-01</p> <p>Mass transfer is the process by which solute is retained in less-mobile porosity domains, and later released into the mobile porosity domain. This process is often responsible for the slow arrival and gradual release of contaminants and solute tracers. Recent studies have outlined methods using dual-domain mass transfer (DDMT) models for characterizing this phenomenon. These models use the non-linear relationship of bulk (σb) and fluid (σf) conductivity, collected from electrical methods during tracer experiments, to characterize the less-mobile/mobile porosity ratio (β) and the mass-transfer rate coefficient (α). DDMT models use the hysteretic σb-σf relationship observed while solute tracers are injected and then flushed from a sample media. Due to limitations in observing the hysteretic σb-σf relationship, this method has not been used to characterize low permeability samples. We have developed an experimental method for testing porous rock cores that allows us to develop a fundamental understanding of contaminant storage and release in consolidated rock. We test the approach on cores from sedimentary rock sites where mass transfer is expected to occur between hydraulically connected fractures and the adjacent low permeability rock matrix. Our method uses a Hassler-type core holder, designed to apply confining pressure around the outside of a sample core, which hydraulically isolates the sample core, allowing water to be injected into it at increased pressures. The experimental apparatus was also designed to measure σb with spectral induced polarization (SIP) measurements, and σf from a sampling port located at the center of the core. Cores were initially saturated with a solution with high electrical conductivity ( 80000 μS/cm). DI water was then injected into the cores at elevated pressures (>60 psi) and the saturating solution was flushed from the cores, in order to generate flow rates fast enough to capture the non-linear σb-σf relationship expected when DDMT occurs. Our initial results demonstrate the existence of a non-linear σb-σf relationship indicative of DDMT for a tight sandstone core from a contaminated fractured rock site. Integrating the electrical results with known physical characteristics of the cores, we are able to quantify the mass transfer characteristics of the cores.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V31A3077D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V31A3077D"><span>Magma chamber cooling by episodic volatile expulsion as constrained by mineral vein distributions in the Butte, Montana Cu-Mo porphyry deposit</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Daly, K.; Karlstrom, L.; Reed, M. H.</p> <p>2016-12-01</p> <p>The role of hydrothermal systems in the thermal evolution of magma chambers is poorly constrained yet likely significant. We analyze trends in mineral composition, vein thickness and overall volumetric fluid flux of the Butte, Montana porphyry Cu-Mo deposit to constrain the role of episodic volatile discharge in the crystallization of the source magma chamber ( 300 km3of silicic magma). An aqueous fluid sourced from injection of porphyritic dikes formed the Butte porphyry Cu network of veins. At least three separate pulses of fluid through the system are defined by alteration envelopes of [1] gray sericite (GS); [2] early-dark micaceous (EDM), pale-green sericite (PGS), and dark-green sericite (DGS); and [3] quartz-molybdenite (Qmb) and barren-quartz. Previous research using geothermometers and geobarometers has found that vein mineral composition, inferred temperatures and inferred pressures vary systematically with depth. Later fluid pulses are characterized by lower temperatures, consistent with progressive cooling of the source. We have digitized previously unused structural data from Butte area drill cores, and applied thermomechanical modeling of fluid release from the source magma chamber through time. Vein number density and vein thickness increase with depth as a clear function of mineralogy and thus primary temperature and pressure. We identify structural trends in the three fluid pulses which seem to imply time evolution of average vein characteristics. Pulses of Qmb-barren quartz and EDM-PGS-DGS (1st and 2nd in time) exhibit increasing vein number density (157 & 95 veins/50m, respectively) and thickness (300mm & 120mm, respectively) as a function of depth. EDM-PGS-DGS has a shallower peak in vein density (800m) than Qmb-barren quartz (>1600m). These data provide the basis for idealized mechanical models of hydrofractures, to predict driving pressures and to compare with existing source temperatures and total fluid volumes in order to estimate the total enthalpy of each fluid pulse. We then compare with models for conductive cooling and crystallization of the source magma chamber to estimate the importance of hydrothermal fluid expulsion in the total heat budget. Such models should also provide constraints on the timing and ultimately the origin of pulsed volatile release at Butte.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26948023','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26948023"><span>Isostructural solid-solid phase transition in monolayers of soft core-shell particles at fluid interfaces: structure and mechanics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rey, Marcel; Fernández-Rodríguez, Miguel Ángel; Steinacher, Mathias; Scheidegger, Laura; Geisel, Karen; Richtering, Walter; Squires, Todd M; Isa, Lucio</p> <p>2016-04-21</p> <p>We have studied the complete two-dimensional phase diagram of a core-shell microgel-laden fluid interface by synchronizing its compression with the deposition of the interfacial monolayer. Applying a new protocol, different positions on the substrate correspond to different values of the monolayer surface pressure and specific area. Analyzing the microstructure of the deposited monolayers, we discovered an isostructural solid-solid phase transition between two crystalline phases with the same hexagonal symmetry, but with two different lattice constants. The two phases corresponded to shell-shell and core-core inter-particle contacts, respectively; with increasing surface pressure the former mechanically failed enabling the particle cores to come into contact. In the phase-transition region, clusters of particles in core-core contacts nucleate, melting the surrounding shell-shell crystal, until the whole monolayer moves into the second phase. We furthermore measured the interfacial rheology of the monolayers as a function of the surface pressure using an interfacial microdisk rheometer. The interfaces always showed a strong elastic response, with a dip in the shear elastic modulus in correspondence with the melting of the shell-shell phase, followed by a steep increase upon the formation of a percolating network of the core-core contacts. These results demonstrate that the core-shell nature of the particles leads to a rich mechanical and structural behavior that can be externally tuned by compressing the interface, indicating new routes for applications, e.g. in surface patterning or emulsion stabilization.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H21C1466G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H21C1466G"><span>Core Flooding Experiments Combined with X-rays and Micro-PET Imaging as a Tool to Calculate Fluid Saturations in a Fracture</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gran, M.; Zahasky, C.; Garing, C.; Pollyea, R. M.; Benson, S. M.</p> <p>2017-12-01</p> <p>One way to reduce CO2 emissions is to capture CO2 generated in power plants and other industrial sources to inject it into a geological formation. Sedimentary basins are the ones traditionally used to store CO2 but the emission sources are not always close to these type of basins. In this case, basalt rocks present a good storage alternative due their extent and also their potential for mineral trapping. Flow through basaltic rocks is governed by the permeable paths provided by rock fractures. Hence, knowing the behavior of the multiphase flow in these fractures becomes crucial. With the aim to describe how aperture and liquid-gas interface changes in the fracture affect relative permeability and what are the implications of permeability stress dependency, a series of core experiments were conducted. To calculate fracture apertures and fluid saturations, core flooding experiments combined with medical X-Ray CT scanner and micro-PET imaging (Micro Positron Emission Tomography) were performed. Capillary pressure and relative permeability drainage curves were simultaneously measured in a fractured basalt core under typical storage reservoir pressures and temperatures. The X-Ray scanner allows fracture apertures to be measured quite accurately even for fractures as small as 30 µ, but obtaining fluid saturations is not straightforward. The micro-PET imaging provides dynamic measurements of tracer distributions which can be used to calculate saturation. Here new experimental data is presented and the challenges associated with measuring fluid saturations using both X-Rays and micro-PET are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940019992','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940019992"><span>Steady induction effects in geomagnetism. Part 1C: Geomagnetic estimation of steady surficial core motions: Application to the definitive geomagnetic reference field models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Voorhies, Coerte V.</p> <p>1993-01-01</p> <p>In the source-free mantle/frozen-flux core magnetic earth model, the non-linear inverse steady motional induction problem was solved using the method presented in Part 1B. How that method was applied to estimate steady, broad-scale fluid velocity fields near the top of Earth's core that induce the secular change indicated by the Definitive Geomagnetic Reference Field (DGRF) models from 1945 to 1980 are described. Special attention is given to the derivation of weight matrices for the DGRF models because the weights determine the apparent significance of the residual secular change. The derived weight matrices also enable estimation of the secular change signal-to-noise ratio characterizing the DGRF models. Two types of weights were derived in 1987-88: radial field weights for fitting the evolution of the broad-scale portion of the radial geomagnetic field component at Earth's surface implied by the DGRF's, and general weights for fitting the evolution of the broad-scale portion of the scalar potential specified by these models. The difference is non-trivial because not all the geomagnetic data represented by the DGRF's constrain the radial field component. For radial field weights (or general weights), a quantitatively acceptable explication of broad-scale secular change relative to the 1980 Magsat epoch must account for 99.94271 percent (or 99.98784 percent) of the total weighted variance accumulated therein. Tolerable normalized root-mean-square weighted residuals of 2.394 percent (or 1.103 percent) are less than the 7 percent errors expected in the source-free mantle/frozen-flux core approximation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..94b2611D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..94b2611D"><span>Importance of core electrostatic properties on the electrophoresis of a soft particle</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De, Simanta; Bhattacharyya, Somnath; Gopmandal, Partha P.</p> <p>2016-08-01</p> <p>The impact of the volumetric charged density of the dielectric rigid core on the electrophoresis of a soft particle is analyzed numerically. The volume charge density of the inner core of a soft particle can arise for a dendrimer structure or bacteriophage MS2. We consider the electrokinetic model based on the conservation principles, thus no conditions for Debye length or applied electric field is imposed. The fluid flow equations are coupled with the ion transport equations and the equation for the electric field. The occurrence of the induced nonuniform surface charge density on the outer surface of the inner core leads to a situation different from the existing analysis of a soft particle electrophoresis. The impact of this induced surface charge density together with the double-layer polarization and relaxation due to ion convection and electromigration is analyzed. The dielectric permittivity and the charge density of the core have a significant impact on the particle electrophoresis when the Debye length is in the order of the particle size. We find that by varying the ionic concentration of the electrolyte, the particle can exhibit reversal in its electrophoretic velocity. The role of the polymer layer softness parameter is addressed in the present analysis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3519363','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3519363"><span>Ca2+ Modulation of ANF-RGC: New Signaling Paradigm Interlocked with Blood Pressure Regulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Duda, Teresa; Pertzev, Alexandre; Sharma, Rameshwar K.</p> <p>2012-01-01</p> <p>ANF-RGC is the prototype receptor membrane guanylate cyclase being both the receptor and the signal transducer of the most hypotensive hormones, ANF and BNP. It is a single trans-membrane protein. After binding these hormones at the extracellular domain, ANF-RGC at its intracellular domain signals the activation of the C-terminal catalytic module and accelerates the production of the second messenger, cyclic GMP, which controls blood pressure, cardiac vasculature, and fluid secretion. At present this is the sole transduction mechanism and the physiological function of ANF-RGC. Through comprehensive studies involving biochemistry, immunohistochemistry, and blood pressure measurements in mice with targeted gene deletions, the present study demonstrates a new signaling model of ANF-RGC that also controls blood pressure. In this model (1) ANF-RGC is not the transducer of ANF and BNP; (2) its extracellular domain is not used for signaling; and (3) the signal-flow is not downstream from the extracellular domain to the core catalytic domain. Instead, the signal is the intracellular Ca2+, which is translated at the site of its reception, at the core catalytic domain of ANF-RGC. A model for this Ca2+ signal transduction is diagrammed. It captures Ca2+ through its Ca2+ sensor myristoylated neurocalcin δ and up-regulates ANF-RGC activity with a K1/2 of 0.5 μM. The neurocalcin δ-modulated domain resides in the 849DIVGFTALSAESTPMQVV866 segment of ANF-RGC, which is a part of the core catalytic domain. Thereby, ANF-RGC is primed to receive, transmit and translate the Ca2+ signals into the generation of cyclic GMP at a rapid rate. The study defines a new paradigm of the membrane guanylate cyclase signaling, which is linked to the physiology of cardiac vasculature regulation and possibly also to fluid secretion. PMID:23088492</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.T11E..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.T11E..05L"><span>Pore Pressure Evolution in Shallow Subduction Earthquake Sequences and Effects on Aseismic Slip Transients -- Numerical Modeling With Rate and State Friction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Y.; Rice, J. R.</p> <p>2005-12-01</p> <p>In 3D modeling of long tectonic loading and earthquake sequences on a shallow subduction fault [Liu and Rice, 2005], with depth-variable rate and state friction properties, we found that aseismic transient slip episodes emerge spontaneously with only a simplified representation of effects of metamorphic fluid release. That involved assumption of a constant in time but uniformly low effective normal stress in the downdip region. As suggested by observations in several major subduction zones [Obara, 2002; Rogers and Dragert, 2003; Kodaira et al, 2004], the presence of fluids, possibly released from dehydration reactions beneath the seismogenic zone, and their pressurization within the fault zone may play an important role in causing aseismic transients and associated non-volcanic tremors. To investigate the effects of fluids in the subduction zone, particularly on the generation of aseismic transients and their various features, we develop a more complete physical description of the pore pressure evolution (specifically, pore pressure increase due to supply from dehydration reactions and shear heating, decrease due to transport and dilatancy during slip), and incorporate that into the rate and state based 3D modeling. We first incorporated two important factors, dilatancy and shear heating, following Segall and Rice [1995, 2004] and Taylor [1998]. In the 2D simulations (slip varies with depth only), a dilatancy-stabilizing effect is seen which slows down the seismic rupture front and can prevent rapid slip from extending all the way to the trench, similarly to Taylor [1998]. Shear heating increases the pore pressure, and results in faster coseismic rupture propagation and larger final slips. In the 3D simulations, dilatancy also stabilizes the along-strike rupture propagation of both seismic and aseismic slips. That is, aseismic slip transients migrate along the strike faster with a shorter Tp (the characteristic time for pore pressure in the fault core to re-equilibrate with that of its surroundings). This is consistent with our previous simulations, which show that the aseismic transients migrate along the strike at a higher speed under a lower, constant in time, effective normal stress. As a combination of the two factors, we show the pore pressure evolution with drops (due to dilatancy during slip) and then rises (due to shear heating) on the fault over multiple time scales. We next plan to formulate, and merge with the slip-rupture analysis, fuller fluid release models based on phase equilibria and models of transport in which the average fault-parallel permeability is a decreasing function of the effective normal stress. The thrust fault zone, at seismogenic depths and slightly downdip, is represented in a conceptually similar manner to the well-studied major continental faults, assuming the fault core materials have a lower permeability than the neighboring damaged zone. Heat diffusion in the fault core and damaged zone will also be considered in the modeling. The simulation results may help to improve our understanding of the processes of the aseismic transients observed within a transform plate boundary along the SAF near Cholame, California [Nadeau and Dolenc, 2005].</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMNG43A1468R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMNG43A1468R"><span>Near-Surface Transport Pathways in the North Atlantic Ocean: Looking for Throughput from the Subtropical to the Subpolar Gyre</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rypina, I. I.; Pratt, L. J.; Lozier, M.</p> <p>2011-12-01</p> <p>Motivated by discrepancies between Eulerian transport estimates and the behavior of Lagrangian surface drifters, near-surface transport pathways and processes in the North Atlantic are studied using a combination of data, altimetric surface heights, statistical analysis of trajectories, and dynamical systems techniques. Particular attention is paid to the issue of the subtropical-to-subpolar intergyre fluid exchange. The velocity field used in this study is composed of a steady drifter-derived background flow, upon which a time-dependent altimeter-based perturbation is superimposed. This analysis suggests that most of the fluid entering the subpolar gyre from the subtropical gyre within two years comes from a narrow region lying inshore of the Gulf Stream core, whereas fluid on the offshore side of the Gulf Stream is largely prevented from doing so by the Gulf Stream core, which acts as a strong transport barrier, in agreement with past studies. The transport barrier near the Gulf Stream core is robust and persistent from 1992 until 2008. The qualitative behavior is found to be largely independent of the Ekman drift.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMagR.283...96G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMagR.283...96G"><span>An improved method for permeability estimation of the bioclastic limestone reservoir based on NMR data</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ge, Xinmin; Fan, Yiren; Liu, Jianyu; Zhang, Li; Han, Yujiao; Xing, Donghui</p> <p>2017-10-01</p> <p>Permeability is an important parameter in formation evaluation since it controls the fluid transportation of porous rocks. However, it is challengeable to compute the permeability of bioclastic limestone reservoirs by conventional methods linking petrophysical and geophysical data, due to the complex pore distributions. A new method is presented to estimate the permeability based on laboratory and downhole nuclear magnetic resonance (NMR) measurements. We divide the pore space into four intervals by the inflection points between the pore radius and the transversal relaxation time. Relationships between permeability and percentages of different pore intervals are investigated to investigate influential factors on the fluid transportation. Furthermore, an empirical model, which takes into account of the pore size distributions, is presented to compute the permeability. 212 core samples in our case show that the accuracy of permeability calculation is improved from 0.542 (SDR model), 0.507 (TIM model), 0.455 (conventional porosity-permeability regressions) to 0.803. To enhance the precision of downhole application of the new model, we developed a fluid correction algorithm to construct the water spectrum of in-situ NMR data, aiming to eliminate the influence of oil on the magnetization. The result reveals that permeability is positively correlated with percentages of mega-pores and macro-pores, but negatively correlated with the percentage of micro-pores. Poor correlation is observed between permeability and the percentage of meso-pores. NMR magnetizations and T2 spectrums after the fluid correction agree well with laboratory results for samples saturated with water. Field application indicates that the improved method provides better performance than conventional models such as Schlumberger-Doll Research equation, Timur-Coates equation, and porosity-permeability regressions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMMR33A2652J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMMR33A2652J"><span>Effects of fluid-rock interactions on faulting within active fault zones - evidence from fault rock samples retrieved from international drilling projects</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janssen, C.; Wirth, R.; Kienast, M.; Yabe, Y.; Sulem, J.; Dresen, G. H.</p> <p>2015-12-01</p> <p>Chemical and mechanical effects of fluids influence the fault mechanical behavior. We analyzed fresh fault rocks from several scientific drilling projects to study the effects of fluids on fault strength. For example, in drill core samples on a rupture plane of an Mw 2.2 earthquake in a deep gold mine in South Africa the main shock occurred on a preexisting plane of weakness that was formed by fluid-rock interaction (magnesiohornblende was intensively altered to chlinochlore). The plane acted as conduit for hydrothermal fluids at some time in the past. The chemical influence of fluids on mineralogical alteration and geomechanical processes in fault core samples from SAFOD (San Andreas Fault Observatory at Depth) is visible in pronounced dissolution-precipitation processes (stylolites, solution seams) as well as in the formation of new phases. Detrital quartz and feldspar grains are partially dissolved and replaced by authigenic illite-smectite (I-S) mixed-layer clay minerals. Transmission Electron Microscopy (TEM) imaging of these grains reveals that the alteration processes and healing were initiated within pores and small intra-grain fissures. Newly formed phyllosilicates growing into open pore spaces likely reduced the fluid permeability. The mechanical influence of fluids is indicated by TEM observations, which document open pores that formed in-situ in the gouge material during or after deformation. Pores were possibly filled with formation water and/or hydrothermal fluids suggesting elevated fluid pressure preventing pore collapse. Fluid-driven healing of fractures in samples from SAFOD and the DGLab Gulf of Corinth project is visible in cementation. Cathodoluminescence microscopy (CL) reveals different generations of calcite veins. Differences in CL-colors suggest repeated infiltration of fluids with different chemical composition from varying sources (formation and meteoric water).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26ES..103a2001N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26ES..103a2001N"><span>Slim hole drilling and testing strategies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nielson, Dennis L.; Garg, Sabodh K.; Goranson, Colin</p> <p>2017-12-01</p> <p>The financial and geologic advantages of drilling slim holes instead of large production wells in the early stages of geothermal reservoir assessment has been understood for many years. However, the practice has not been fully embraced by geothermal developers. We believe that the reason for this is that there is a poor understanding of testing and reservoir analysis that can be conducted in slim holes. In addition to reservoir engineering information, coring through the cap rock and into the reservoir provides important data for designing subsequent production well drilling and completion. Core drilling requires significantly less mud volume than conventional rotary drilling, and it is typically not necessary to cure lost circulation zones (LCZ). LCZs should be tested by either production or injection methods as they are encountered. The testing methodologies are similar to those conducted on large-diameter wells; although produced and/or injected fluid volumes are much less. Pressure, temperature and spinner (PTS) surveys in slim holes under static conditions can used to characterize temperature and pressure distribution in the geothermal reservoir. In many cases it is possible to discharge slim holes and obtain fluid samples to delineate the geochemical properties of the reservoir fluid. Also in the latter case, drawdown and buildup data obtained using a downhole pressure tool can be employed to determine formation transmissivity and well properties. Even if it proves difficult to discharge a slim hole, an injection test can be performed to obtain formation transmissivity. Given the discharge (or injection) data from a slimhole, discharge properties of a large-diameter well can be inferred using wellbore modeling. Finally, slim hole data (pressure, temperature, transmissivity, fluid properties) together with reservoir simulation can help predict the ability of the geothermal reservoir to sustain power production.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1207..258W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1207..258W"><span>Experimental Research on the Dense CFB's Riser and the Simulation Based on the EMMS Model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, X. Y.; Wang, S. D.; Fan, B. G.; Liao, L. L.; Jiang, F.; Xu, X.; Wu, X. Z.; Xiao, Y. H.</p> <p>2010-03-01</p> <p>The flow structure in the CFB (circulating fluidized bed) riser has been investigated. Experimental studies were performed in a cold square section unit with 270 mm×270 mm×10 m. Since the drag force model based on homogeneous two-phase flow such as the Gidaspow drag model could not depict the heterogeneous structures of the gas-solid flow, the structure-dependent energy-minimization multi-scale (EMMS) model based on the heterogenerity was applied in the paper and a revised drag force model based on the EMMS model was proposed. A 2D two-fluid model was used to simulate a bench-scale square cross-section riser of a cold CFB. The typical core-annulus structure and the back-mixing near the wall of the riser were observed and the assembly and fragmentation processes of clusters were captured. By comparing with the Gidaspow drag model, the results obtained by the revised drag model based on EMMS shows better consistency with the experimental data. The model can also depict the difference from the two exit configurations. This study once again proves the key role of drag force in CFD (Computational Fluid Dynamics) simulation and also shows the availability of the revised drag model to describe the gas-solid flow in CFB risers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21350404-measuring-air-core-characteristics-pressure-swirl-atomizer-via-transparent-acrylic-nozzle-various-reynolds-numbers','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21350404-measuring-air-core-characteristics-pressure-swirl-atomizer-via-transparent-acrylic-nozzle-various-reynolds-numbers"><span>Measuring air core characteristics of a pressure-swirl atomizer via a transparent acrylic nozzle at various Reynolds numbers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lee, Eun J.; Oh, Sang Youp; Kim, Ho Y.</p> <p>2010-11-15</p> <p>Because of thermal fluid-property dependence, atomization stability (or flow regime) can change even at fixed operating conditions when subject to temperature change. Particularly at low temperatures, fuel's high viscosity can prevent a pressure-swirl (or simplex) atomizer from sustaining a centrifugal-driven air core within the fuel injector. During disruption of the air core inside an injector, spray characteristics outside the nozzle reflect a highly unstable, nonlinear mode where air core length, Sauter mean diameter (SMD), cone angle, and discharge coefficient variability. To better understand injector performance, these characteristics of the pressure-swirl atomizer were experimentally investigated and data were correlated to Reynoldsmore » numbers (Re). Using a transparent acrylic nozzle, the air core length, SMD, cone angle, and discharge coefficient are observed as a function of Re. The critical Reynolds numbers that distinguish the transition from unstable mode to transitional mode and eventually to a stable mode are reported. The working fluids are diesel and a kerosene-based fuel, referred to as bunker-A. (author)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22071767','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22071767"><span>An impact-driven dynamo for the early Moon.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Le Bars, M; Wieczorek, M A; Karatekin, O; Cébron, D; Laneuville, M</p> <p>2011-11-09</p> <p>The origin of lunar magnetic anomalies remains unresolved after their discovery more than four decades ago. A commonly invoked hypothesis is that the Moon might once have possessed a thermally driven core dynamo, but this theory is problematical given the small size of the core and the required surface magnetic field strengths. An alternative hypothesis is that impact events might have amplified ambient fields near the antipodes of the largest basins, but many magnetic anomalies exist that are not associated with basin antipodes. Here we propose a new model for magnetic field generation, in which dynamo action comes from impact-induced changes in the Moon's rotation rate. Basin-forming impact events are energetic enough to have unlocked the Moon from synchronous rotation, and we demonstrate that the subsequent large-scale fluid flows in the core, excited by the tidal distortion of the core-mantle boundary, could have powered a lunar dynamo. Predicted surface magnetic field strengths are on the order of several microteslas, consistent with palaeomagnetic measurements, and the duration of these fields is sufficient to explain the central magnetic anomalies associated with several large impact basins.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19710000356','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19710000356"><span>Improved diamond coring bits developed for dry and chip-flush drilling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Decker, W. E.; Hampe, W. R.; Hampton, W. H.; Simon, A. B.</p> <p>1971-01-01</p> <p>Two rotary diamond bit designs, one operating with a chip-flushing fluid, the second including auger section to remove drilled chips, enhance usefulness of tool for exploratory and industrial core-drilling of hard, abrasive mineral deposits and structural masonry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11757918','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11757918"><span>Simplified method to solve sound transmission through structures lined with elastic porous material.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, J H; Kim, J</p> <p>2001-11-01</p> <p>An approximate analysis method is developed to calculate sound transmission through structures lined with porous material. Because the porous material has both the solid phase and fluid phase, three wave components exist in the material, which makes the related analysis very complicated. The main idea in developing the approximate method is very simple: modeling the porous material using only the strongest of the three waves, which in effect idealizes the material as an equivalent fluid. The analysis procedure has to be conducted in two steps. In the first step, sound transmission through a flat double panel with a porous liner of infinite extents, which has the same cross sectional construction as the actual structure, is solved based on the full theory and the strongest wave component is identified. In the second step sound transmission through the actual structure is solved modeling the porous material as an equivalent fluid while using the actual geometry of the structure. The development and validation of the method are discussed in detail. As an application example, the transmission loss through double walled cylindrical shells with a porous core is calculated utilizing the simplified method.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22403212-leapfrogging-multiple-coaxial-viscous-vortex-rings','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22403212-leapfrogging-multiple-coaxial-viscous-vortex-rings"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cheng, M., E-mail: chengm@ihpc.a-star.edu.sg; Lou, J.; Lim, T. T.</p> <p></p> <p>A recent theoretical study [Borisov, Kilin, and Mamaev, “The dynamics of vortex rings: Leapfrogging, choreographies and the stability problem,” Regular Chaotic Dyn. 18, 33 (2013); Borisov et al., “The dynamics of vortex rings: Leapfrogging in an ideal and viscous fluid,” Fluid Dyn. Res. 46, 031415 (2014)] shows that when three coaxial vortex rings travel in the same direction in an incompressible ideal fluid, each of the vortex rings alternately slips through (or leapfrogs) the other two ahead. Here, we use a lattice Boltzmann method to simulate viscous vortex rings with an identical initial circulation, radius, and separation distance with themore » aim of studying how viscous effect influences the outcomes of the leapfrogging process. For the case of two identical vortex rings, our computation shows that leapfrogging can be achieved only under certain favorable conditions, which depend on Reynolds number, vortex core size, and initial separation distance between the two rings. For the case of three coaxial vortex rings, the result differs from the inviscid model and shows that the second vortex ring always slips through the leading ring first, followed by the third ring slipping through the other two ahead. A simple physical model is proposed to explain the observed behavior.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22105695-equilibrium-cycle-pin-pin-transport-depletion-calculations-decart','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22105695-equilibrium-cycle-pin-pin-transport-depletion-calculations-decart"><span>Equilibrium cycle pin by pin transport depletion calculations with DeCART</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kochunas, B.; Downar, T.; Taiwo, T.</p> <p></p> <p>As the Advanced Fuel Cycle Initiative (AFCI) program has matured it has become more important to utilize more advanced simulation methods. The work reported here was performed as part of the AFCI fellowship program to develop and demonstrate the capability of performing high fidelity equilibrium cycle calculations. As part of the work here, a new multi-cycle analysis capability was implemented in the DeCART code which included modifying the depletion modules to perform nuclide decay calculations, implementing an assembly shuffling pattern description, and modifying iteration schemes. During the work, stability issues were uncovered with respect to converging simultaneously the neutron flux,more » isotopics, and fluid density and temperature distributions in 3-D. Relaxation factors were implemented which considerably improved the stability of the convergence. To demonstrate the capability two core designs were utilized, a reference UOX core and a CORAIL core. Full core equilibrium cycle calculations were performed on both cores and the discharge isotopics were compared. From this comparison it was noted that the improved modeling capability was not drastically different in its prediction of the discharge isotopics when compared to 2-D single assembly or 2-D core models. For fissile isotopes such as U-235, Pu-239, and Pu-241 the relative differences were 1.91%, 1.88%, and 0.59%), respectively. While this difference may not seem large it translates to mass differences on the order of tens of grams per assembly, which may be significant for the purposes of accounting of special nuclear material. (authors)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28189155','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28189155"><span>Contamination Control for Scientific Drilling Operations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kallmeyer, J</p> <p>2017-01-01</p> <p>Drilling is an integral part of subsurface exploration. Because almost all drilling operations require the use of a drill fluid, contamination by infiltration of drill fluid into the recovered core material cannot be avoided. Because it is impossible to maintain sterile conditions during drilling the drill fluid will contain surface microbes and other contaminants. As contamination cannot be avoided, it has to be tracked to identify those parts of the drill core that were not infiltrated by the drill fluid. This is done by the addition of tracer compounds. A great variety of tracers is available, and the choice depends on many factors. This review will first explain the basic principles of drilling before presenting the most common tracers and discussing their strengths and weaknesses. The final part of this review presents a number of key questions that have to be addressed in order to find the right tracer for a particular drilling operation. Copyright © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AdWR..115....1Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AdWR..115....1Z"><span>Micro-positron emission tomography for measuring sub-core scale single and multiphase transport parameters in porous media</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zahasky, Christopher; Benson, Sally M.</p> <p>2018-05-01</p> <p>Accurate descriptions of heterogeneity in porous media are important for understanding and modeling single phase (e.g. contaminant transport, saltwater intrusion) and multiphase (e.g. geologic carbon storage, enhanced oil recovery) transport problems. Application of medical imaging to experimentally quantify these processes has led to significant progress in material characterization and understanding fluid transport behavior at laboratory scales. While widely utilized in cancer diagnosis and management, cardiology, and neurology, positron emission tomography (PET) has had relatively limited applications in earth science. This study utilizes a small-bore micro-PET scanner to image and quantify the transport behavior of pulses of a conservative aqueous radiotracer injected during single and multiphase flow experiments in two heterogeneous Berea sandstone cores. The cores are discretized into axial-parallel streamtubes, and using the reconstructed micro-PET data, expressions are derived from spatial moment analysis for calculating sub-core tracer flux and pore water velocity. Using the flux and velocity measurements, it is possible to calculate porosity and saturation from volumetric flux balance, and calculate permeability and water relative permeability from Darcy's law. Second spatial moment analysis enables measurement of sub-core solute dispersion during both single phase and multiphase experiments. A numerical simulation model is developed to verify the assumptions of the streamtube dimension reduction technique. A variation of the reactor ratio is presented as a diagnostic metric to efficiently determine the validity of the streamtube approximation in core and column-scale experiments. This study introduces a new method to quantify sub-core permeability, relative permeability, and dispersion. These experimental and analytical methods provide a foundation for future work on experimental measurements of differences in transport behavior across scales.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/883366','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/883366"><span>WETTABILITY AND PREDICTION OF OIL RECOVERY FROM RESERVOIRS DEVELOPED WITH MODERN DRILLING AND COMPLETION FLUIDS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jill S. Buckley; Norman R. Morrow</p> <p>2006-01-01</p> <p>The objectives of this project are: (1) to improve understanding of the wettability alteration of mixed-wet rocks that results from contact with the components of synthetic oil-based drilling and completion fluids formulated to meet the needs of arctic drilling; (2) to investigate cleaning methods to reverse the wettability alteration of mixed-wet cores caused by contact with these SBM components; and (3) to develop new approaches to restoration of wetting that will permit the use of cores drilled with SBM formulations for valid studies of reservoir properties.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25667157','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25667157"><span>Fluid intake, hydration, work physiology of wildfire fighters working in the heat over consecutive days.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Raines, Jenni; Snow, Rodney; Nichols, David; Aisbett, Brad</p> <p>2015-06-01</p> <p>(i) To evaluate firefighters' pre- and post-shift hydration status across two shifts of wildfire suppression work in hot weather conditions. (ii) To document firefighters' fluid intake during and between two shifts of wildfire suppression work. (iii) To compare firefighters' heart rate, activity, rating of perceived exertion (RPE), and core temperature across the two consecutive shifts of wildfire suppression work. Across two consecutive days, 12 salaried firefighters' hydration status was measured immediately pre- and post-shift. Hydration status was also measured 2h post-shift. RPE was also measured immediately post-shift on each day. Work activity, heart rate, and core temperature were logged continuously during each shift. Ten firefighters also manually recorded their food and fluid intake before, during, and after both fireground shifts. Firefighters were not euhydrated at all measurement points on Day one (292±1 mOsm l(-1)) and euhydrated across these same time points on Day two (289±0.5 mOsm l(-1)). Fluid consumption following firefighters' shift on Day one (1792±1134ml) trended (P = 0.08) higher than Day two (1108±1142ml). Daily total fluid intake was not different (P = 0.27), averaging 6443±1941ml across both days. Core temperature and the time spent ≥ 70%HRmax were both elevated on Day one (when firefighters were not euhydrated). Firefighters' work activity profile was not different between both days of work. There was no difference in firefighters' pre- to post-shift hydration within each shift, suggesting ad libitum drinking was at least sufficient to maintain pre-shift hydration status, even in hot conditions. Firefighters' relative hypohydration on Day one (despite a slightly lower ambient temperature) may have been associated with elevations in core temperature, more time in the higher heart rate zones, and 'post-shift' RPE. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011HydJ...19..237A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011HydJ...19..237A"><span>Helium measurements of pore fluids obtained from the San Andreas Fault Observatory at Depth (SAFOD, USA) drill cores</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ali, S.; Stute, M.; Torgersen, T.; Winckler, G.; Kennedy, B. M.</p> <p>2011-02-01</p> <p>4He accumulated in fluids is a well established geochemical tracer used to study crustal fluid dynamics. Direct fluid samples are not always collectable; therefore, a method to extract rare gases from matrix fluids of whole rocks by diffusion has been adapted. Helium was measured on matrix fluids extracted from sandstones and mudstones recovered during the San Andreas Fault Observatory at Depth (SAFOD) drilling in California, USA. Samples were typically collected as subcores or from drillcore fragments. Helium concentration and isotope ratios were measured 4-6 times on each sample, and indicate a bulk 4He diffusion coefficient of 3.5 ± 1.3 × 10-8 cm2 s-1 at 21°C, compared to previously published diffusion coefficients of 1.2 × 10-18 cm2 s-1 (21°C) to 3.0 × 10-15 cm2 s-1 (150°C) in the sands and clays. Correcting the diffusion coefficient of 4Hewater for matrix porosity (˜3%) and tortuosity (˜6-13) produces effective diffusion coefficients of 1 × 10-8 cm2 s-1 (21°C) and 1 × 10-7 (120°C), effectively isolating pore fluid 4He from the 4He contained in the rock matrix. Model calculations indicate that <6% of helium initially dissolved in pore fluids was lost during the sampling process. Complete and quantitative extraction of the pore fluids provide minimum in situ porosity values for sandstones 2.8 ± 0.4% (SD, n = 4) and mudstones 3.1 ± 0.8% (SD, n = 4).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21371457-contributions-regarding-aircraft-nuclear-propulsion','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21371457-contributions-regarding-aircraft-nuclear-propulsion"><span>Contributions Regarding the Aircraft Nuclear Propulsion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Mitrica, Bogdan; Petre, Marian; Dima, Mihai Octavian</p> <p>2010-01-21</p> <p>The possibility to use a nuclear reactor for airplanes propulsion was investigated taking in to account 2 possible solutions: the direct cycle (where the fluid pass through the reactor's core) and the indirect cycle (where the fluid is passing through a heat exchanger). Taking in to account the radioprotection problems, the only realistic solution seems to be the indirect cycle, where the energy transfer should be performed by a heat exchanger that must work at very high speed of the fluid. The heat exchanger will replace the classical burning room. We had performed a more precise theoretical study for themore » nuclear jet engine regarding the performances of the nuclear reactor, of the heat exchanger and of the jet engine. It was taken in to account that in the moment when the burning room is replaced by a heat exchanger, a new model for gasodynamic process from the engine must be performed. Studies regarding the high flow speed heat transfer were performed.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFD.A4005T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFD.A4005T"><span>Coupling molecular dynamics with lattice Boltzmann method based on the immersed boundary method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, Jifu; Sinno, Talid; Diamond, Scott</p> <p>2017-11-01</p> <p>The study of viscous fluid flow coupled with rigid or deformable solids has many applications in biological and engineering problems, e.g., blood cell transport, drug delivery, and particulate flow. We developed a partitioned approach to solve this coupled Multiphysics problem. The fluid motion was solved by Palabos (Parallel Lattice Boltzmann Solver), while the solid displacement and deformation was simulated by LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). The coupling was achieved through the immersed boundary method (IBM). The code modeled both rigid and deformable solids exposed to flow. The code was validated with the classic problem of rigid ellipsoid particle orbit in shear flow, blood cell stretching test and effective blood viscosity, and demonstrated essentially linear scaling over 16 cores. An example of the fluid-solid coupling was given for flexible filaments (drug carriers) transport in a flowing blood cell suspensions, highlighting the advantages and capabilities of the developed code. NIH 1U01HL131053-01A1.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24268258','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24268258"><span>NaF-loaded core-shell PAN-PMMA nanofibers as reinforcements for Bis-GMA/TEGDMA restorative resins.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheng, Liyuan; Zhou, Xuegang; Zhong, Hong; Deng, Xuliang; Cai, Qing; Yang, Xiaoping</p> <p>2014-01-01</p> <p>A kind of core-shell nanofibers containing sodium fluoride (NaF) was produced and used as reinforcing materials for dimethacrylate-based dental restorative resins in this study. The core-shell nanofibers were prepared by coaxial-electrospinning with polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) solutions as core and shell fluids, respectively. The produced PAN-PMMA nanofibers varied in fiber diameter and the thickness of PMMA shell depending on electrospinning parameters. NaF-loaded nanofibers were obtained by incorporating NaF nanocrystals into the core fluid at two loadings (0.8 or 1.0wt.%). Embedment of NaF nanocrystals into the PAN core did not damage the core-shell structure. The addition of PAN-PMMA nanofibers into Bis-GMA/TEGDMA clearly showed the reinforcement due to the good interfacial adhesion between fibers and resin. The flexural strength (Fs) and flexural modulus (Ey) of the composites decreased slightly as the thickness of PMMA shell increasing. Sustained fluoride releases with minor initial burst release were achieved from NaF-loaded core-shell nanofibers and the corresponding composites, which was quite different from the case of embedding NaF nanocrystals into the dental resin directly. The study demonstrated that NaF-loaded PAN-PMMA core-shell nanofibers were not only able to improve the mechanical properties of restorative resin, but also able to provide sustained fluoride release to help in preventing secondary caries. © 2013.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T53C1588M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T53C1588M"><span>Syntectonic fluid flux during rift faulting: Record from the MIS core, Victoria Land Basin, Antarctica</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Millan, C.; Wilson, T. J.; Paulsen, T. S.</p> <p>2009-12-01</p> <p>The McMurdo Ice Shelf project successfully recovered 1285 m of Neogene sedimentary core from the Victoria Land Basin, a large rift basin within the West Antarctic Rift System (WARS) of Antarctica. The core contains 1475 natural fractures that were logged as faults, veins and clastic dikes, associated with the southern extension of the Neogene-active? Terror Rift fault zone. Veins constitute about 625 of this population. Most veins are filled with calcite, although zeolites and minor chlorite are common towards the bottom of the core. In the lower ~300 m of the core, veins contain opening-mode fiber fills and are wavy to tightly folded due to vertical shortening. Folded, opening-mode folded veins are filled by calcite fibers that grew normal to vein walls, indicating the host sediment was cohesive enough to fracture but was not fully lithified and accommodated vein buckling during compaction. Fold hinges are fractured and wedging of vein segments is marked by overlapping tips separated by zones with strong chlorite and clay fabrics, suggesting shearing during further vertical contraction of the host rock. Calcite veins are commonly strongly twinned. Cathodoluminescence microscopy shows minor changes in color and intensity and minimal concentric or sectoral zoning, suggesting relatively rapid crystallization of fluids of similar chemistry. However, stable isotope analyses reveal large variations in values, with carbon values ranging from -21.91 to -7.15 (VPBD) and oxygen values ranging from -5.35 to -11.97 (VPBD). Further detailed investigation of the fracture fills using cathodoluminescence and electron microscopy combined with isotopic analysis of carbon and oxygen will document the generations of the filling material in more detail and will constrain the sources and evolution of the fluids. There has clearly been significant structural control on fluid pathways during lithification, compaction and diagenesis of strata deforming within the Terror Rift zone.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPhCS.547a2030C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhCS.547a2030C"><span>Numerical evaluation of gas core length in free surface vortices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cristofano, L.; Nobili, M.; Caruso, G.</p> <p>2014-11-01</p> <p>The formation and evolution of free surface vortices represent an important topic in many hydraulic intakes, since strong whirlpools introduce swirl flow at the intake, and could cause entrainment of floating matters and gas. In particular, gas entrainment phenomena are an important safety issue for Sodium cooled Fast Reactors, because the introduction of gas bubbles within the core causes dangerous reactivity fluctuation. In this paper, a numerical evaluation of the gas core length in free surface vortices is presented, according to two different approaches. In the first one, a prediction method, developed by the Japanese researcher Sakai and his team, has been applied. This method is based on the Burgers vortex model, and it is able to estimate the gas core length of a free surface vortex starting from two parameters calculated with single-phase CFD simulations. The two parameters are the circulation and the downward velocity gradient. The other approach consists in performing a two-phase CFD simulation of a free surface vortex, in order to numerically reproduce the gas- liquid interface deformation. Mapped convergent mesh is used to reduce numerical error and a VOF (Volume Of Fluid) method was selected to track the gas-liquid interface. Two different turbulence models have been tested and analyzed. Experimental measurements of free surface vortices gas core length have been executed, using optical methods, and numerical results have been compared with experimental measurements. The computational domain and the boundary conditions of the CFD simulations were set consistently with the experimental test conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DPPN11133K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DPPN11133K"><span>Development of SSUBPIC code for modeling the neutral gas depletion effect in helicon discharges</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kollasch, Jeffrey; Sovenic, Carl; Schmitz, Oliver</p> <p>2017-10-01</p> <p>The SSUBPIC (steady-state unstructured-boundary particle-in-cell) code is being developed to model helicon plasma devices. The envisioned modeling framework incorporates (1) a kinetic neutral particle model, (2) a kinetic ion model, (3) a fluid electron model, and (4) an RF power deposition model. The models are loosely coupled and iterated until convergence to steady-state. Of the four required solvers, the kinetic ion and neutral particle simulation can now be done within the SSUBPIC code. Recent SSUBPIC modifications include implementation and testing of a Coulomb collision model (Lemons et al., JCP, 228(5), pp. 1391-1403) allowing efficient coupling of kineticly-treated ions to fluid electrons, and implementation of a neutral particle tracking mode with charge-exchange and electron impact ionization physics. These new simulation capabilities are demonstrated working independently and coupled to ``dummy'' profiles for RF power deposition to converge on steady-state plasma and neutral profiles. The geometry and conditions considered are similar to those of the MARIA experiment at UW-Madison. Initial results qualitatively show the expected neutral gas depletion effect in which neutrals in the plasma core are not replenished at a sufficient rate to sustain a higher plasma density. This work is funded by the NSF CAREER award PHY-1455210 and NSF Grant PHY-1206421.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820052776&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dearths%2Bouter%2Bcore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820052776&hterms=earths+outer+core&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dearths%2Bouter%2Bcore"><span>A diurnal resonance in the ocean tide and in the earth's load response due to the resonant free 'core nutation'</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wahr, J. M.; Sasao, T.</p> <p>1981-01-01</p> <p>The effects of the oceans, which are subject to a resonance due to a free rotational eigenmode of an elliptical, rotating earth with a fluid outer core having an eigenfrequency of (1 + 1/460) cycle/day, on the body tide and nutational response of the earth to the diurnal luni-tidal force are computed. The response of an elastic, rotating, elliptical, oceanless earth with a fluid outer core to a given load distribution on its surface is first considered, and the tidal sea level height for equilibrium and nonequilibrium oceans is examined. Computations of the effects of equilibrium and nonequilibrium oceans on the nutational and deformational responses of the earth are then presented which show small but significant perturbations to the retrograde 18.6-year and prograde six-month nutations, and more important effects on the earth body tide, which is also resonant at the free core notation eigenfrequency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.3564P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.3564P"><span>The GEOFLOW experiment missions in the Fluid Science Laboratory on ISS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Picker, Gerold; Carpy, Rodrigo; Fabritius, Gerd; Dettmann, Jan; Minster, Olivier; Winter, Josef; Ranebo, Hans; Dewandre, Thierry; Castiglione, Luigi; Mazzoni, Stefano; Egbers, Christoph; Futterer, Birgit</p> <p></p> <p>The GEOFLOW I experiment has been successfully performed on the International Space Sta-tion (ISS) in 2008 in the Columbus module in order to study the stability, pattern formation and transition to turbulence in a viscous incompressible fluid layer enclosed in two concentric co-rotating spheres subject to a radial temperature gradient and a radial volumetric force field. The objective of the study is the experimental investigation of large scale astrophysical and geophysical phenomena in spherical geometry stipulated by rotation, thermal convections and radial gravity fields. These systems include earth outer core or mantle convection, differen-tial rotation effects in the sun, atmosphere of gas planets as well as a variety of engineering applications. The GEOFLOW I experimental instrument consists of an experiment insert for operation in the Fluid Science Laboratory, which is part of the Columbus Module of the ISS. It was first launched in February 2008 together with Columbus Module on STS 122, operated periodically for 9 month and returned to ground after 14 month on orbit with STS 119. The primary objective was the experimental modelling of outer earth core convection flow. In order to allow for variations of the characteristic scaling for different physical phenomena, the experiment was designed and qualified for a total of nine flights to the ISS, with ground refurbishment and geometrical or fluid modification after each mission. The second mission of GEOFLOW (II) is currently under preparation in terms of hardware refurbishment and modification, as well as science parameter development in order to allow use of a new experimental model fluid with a strongly temperature dependent viscosity, a adaptation of the experimental thermal parameter range in order to provide a representative model for earth mantle convection. The GEOFLOW II instrument is foreseen to be launched with the second mission of the Eu-ropean Automated Transfer Vehicle (ATV). The flight to ISS is planned on ATV 2 "Johannes-Kepler" and foreseen for launch with Ariane 5 in November / December 2010. The objective of the presentation is to give an overview on the Geoflow instrument, its scien-tific performances, the experimental procedures with particular focus on the evolution of the instrument and experiment from its first mission to the second mission. The GEOFLOW project is funded by ESA/ESTEC for the industrial activities and the support of the GEOFLOW science topical team and by German Aerospace Center DLR for the ground based research at BTU Cottbus/Germany. The flight hardware was developed and built by an industrial team led by ASTRIUM Space Transportation Friedrichshafen/Germany.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AsBio...8.1023F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AsBio...8.1023F"><span>Underground Habitats in the Río Tinto Basin: A Model for Subsurface Life Habitats on Mars</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernández-Remolar, David C.; Prieto-Ballesteros, Olga; Rodríguez, Nuria; Gómez, Felipe; Amils, Ricardo; Gómez-Elvira, Javier; Stoker, Carol R.</p> <p>2008-10-01</p> <p>A search for evidence of cryptic life in the subsurface region of a fractured Paleozoic volcanosedimentary deposit near the source waters of the Río Tinto River (Iberian pyrite belt, southwest Spain) was carried out by Mars Astrobiology Research and Technology Experiment (MARTE) project investigators in 2003 and 2004. This conventional deep-drilling experiment is referred to as the MARTE ground truth drilling project. Boreholes were drilled at three sites, and samples from extracted cores were analyzed with light microscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Core leachates were analyzed with ion chromatography, and borehole fluids were analyzed with ion and gas chromatography. Key variables of the groundwater system (e.g. , pO2, pH, and salinity) exhibit huge ranges probably due to surficial oxygenation of overall reducing waters, physical mixing of waters, and biologically mediated water-rock interactions. Mineral distribution is mainly driven by the pH of subsurface solutions, which range from highly acidic to neutral. Borehole fluids contain dissolved gases such as CO2, CH4, and H2. SEM-EDS analyses of core samples revealed evidence of microbes attacking pyrite. The Río Tinto alteration mechanisms may be similar to subsurface weathering of the martian crust and provide insights into the possible (bio)geochemical cycles that may have accompanied underground habitats in extensive early Mars volcanic regions and associated sulfide ores.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19105758','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19105758"><span>Underground habitats in the Río Tinto basin: a model for subsurface life habitats on Mars.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernández-Remolar, David C; Prieto-Ballesteros, Olga; Rodríguez, Nuria; Gómez, Felipe; Amils, Ricardo; Gómez-Elvira, Javier; Stoker, Carol R</p> <p>2008-10-01</p> <p>A search for evidence of cryptic life in the subsurface region of a fractured Paleozoic volcanosedimentary deposit near the source waters of the Río Tinto River (Iberian pyrite belt, southwest Spain) was carried out by Mars Astrobiology Research and Technology Experiment (MARTE) project investigators in 2003 and 2004. This conventional deep-drilling experiment is referred to as the MARTE ground truth drilling project. Boreholes were drilled at three sites, and samples from extracted cores were analyzed with light microscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Core leachates were analyzed with ion chromatography, and borehole fluids were analyzed with ion and gas chromatography. Key variables of the groundwater system (e.g., pO(2), pH, and salinity) exhibit huge ranges probably due to surficial oxygenation of overall reducing waters, physical mixing of waters, and biologically mediated water-rock interactions. Mineral distribution is mainly driven by the pH of subsurface solutions, which range from highly acidic to neutral. Borehole fluids contain dissolved gases such as CO(2), CH(4), and H(2). SEM-EDS analyses of core samples revealed evidence of microbes attacking pyrite. The Río Tinto alteration mechanisms may be similar to subsurface weathering of the martian crust and provide insights into the possible (bio)geochemical cycles that may have accompanied underground habitats in extensive early Mars volcanic regions and associated sulfide ores.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940028960','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940028960"><span>HSCT noise reduction technology development at GE Aircraft Engines</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Majjigi, Rudramuni K.</p> <p>1992-01-01</p> <p>The topics covered include the following: High Speed Civil Transport (HSCT) exhaust nozzle design approaches; GE aircraft engine (GEAE) HSCT acoustics research; 2DCD non-IVP suppressor ejector; key sensitivities from reference aircraft; acoustic experiments; aero-mixing experimental set-up; fluid shield nozzle; HSCT Mach 2.4 flade nozzle; noise prediction; nozzle concept for GE/Boeing joint test; scale model hot core flow path modified to prevent hub-choking CFL3-D solution; HSCT exhaust nozzle status; and key acoustic technology issues for HSCT's.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992hsrs.work..553M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992hsrs.work..553M"><span>HSCT noise reduction technology development at GE Aircraft Engines</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Majjigi, Rudramuni K.</p> <p>1992-04-01</p> <p>The topics covered include the following: High Speed Civil Transport (HSCT) exhaust nozzle design approaches; GE aircraft engine (GEAE) HSCT acoustics research; 2DCD non-IVP suppressor ejector; key sensitivities from reference aircraft; acoustic experiments; aero-mixing experimental set-up; fluid shield nozzle; HSCT Mach 2.4 flade nozzle; noise prediction; nozzle concept for GE/Boeing joint test; scale model hot core flow path modified to prevent hub-choking CFL3-D solution; HSCT exhaust nozzle status; and key acoustic technology issues for HSCT's.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA581358','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA581358"><span>Preventing Hypothermia: Comparison of Current Devices Used by the U.S. Army with an In Vitro Warmed Crystalloid Fluid Model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-04-01</p> <p>the start of the experiment and remained so throughout the rest of the experimental period (Fig 4, Table 2). Mean core temperature observed was 36.72...removal [4, 9]. At temperatures less than 32ºC the body experiences a severe decrease in intrinsic metabolic rate. At less than 24ºC endocrine...in the field are thus forced to base their procurement decisions on either personal anecdotal experience or manufacturer claims of performance or</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1014788-lattice-boltzmann-framework-simulation-boiling-hydrodynamics-bwrs','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1014788-lattice-boltzmann-framework-simulation-boiling-hydrodynamics-bwrs"><span>A Lattice Boltzmann Framework for the simulation of boiling hydrodynamics in BWRs.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jain, P. K.; Tentner, A.; Uddin, R.</p> <p>2008-01-01</p> <p>Multi phase and multi component flows are ubiquitous in nature as well as in many man-made processes. A specific example is the Boiling Water Reactor (BWR) core, in which the coolant enters the core as liquid, undergoes a phase change as it traverses the core and exits as a high quality two-phase mixture. Two-phase flows in BWRs typically manifest a wide variety of geometrical patterns of the co-existing phases depending on the local system conditions. Modeling of such flows currently relies on empirical correlations (for example, in the simulation of bubble nucleation, bubble growth and coalescence, and inter-phase surface topologymore » transitions) that hinder the accurate simulation of two-phase phenomena using Computational Fluid Dynamics (CFD) approaches. The Lattice Boltzmann Method (LBM) is in rapid development as a modeling tool to understand these macro-phenomena by coupling them with their underlying micro-dynamics. This paper presents a consistent LBM formulation for the simulation of a two-phase water-steam system. Results of initial model validation in a range of thermodynamic conditions typical for BWRs are also shown. The interface between the two coexisting phases is captured from the dynamics of the model itself, i.e., no interface tracking is needed. The model is based on the Peng-Robinson (P-R) non-ideal equation of state and can quantitatively approximate the phase-coexistence curve for water at different temperatures ranging from 125 to 325 oC. Consequently, coexisting phases with large density ratios (up to {approx}1000) may be simulated. Two-phase models in the 200-300 C temperature range are of significant importance to nuclear engineers since most BWRs operate under similar thermodynamic conditions. Simulation of bubbles and droplets in a gravity-free environment of the corresponding coexisting phase until steady state is reached satisfies Laplace law at different temperatures and thus, yield the surface tension of the fluid. Comparing the LBM surface tension thus calculated using the LBM to the corresponding experimental values for water, the LBM lattice unit (lu) can be scaled to the physical units. Using this approach, spatial scaling of the LBM emerges from the model itself and is not imposed externally.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040031692','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040031692"><span>The Effect of Surface Topography on the Nonlinear Dynamics of Rossby Waves</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abarzhi, S. I.; Desjardins, O.; Pitsch, H.</p> <p>2003-01-01</p> <p>Boussinesq convection in rotating systems attracts a sustained attention of the fluid dynamics community, because it has intricate non-linear dynamics (Cross & Hohenberg 1993) and plays an important role in geophysical and astrophysical applications, such as the motion of the liquid outer core of Earth, the Red Spot in Jupiter, the giant cells in the Sun etc. (Alridge et al. 1990). A fundamental distinction between the real geo- and astrophysical problems and the idealized laboratory studies is that natural systems are inhomogeneous (Alridge et al. 1990). Heterogeneities modulate the flow and influence significantly the dynamics of convective patterns (Alridge et al. 1990; Hide 1971). The effect of modulations on pattern formation and transition to turbulence in Boussinesq convection is far from being completely understood (Cross & Hohenberg 1993; Aranson & Kramer 2002). It is generally accepted that in the liquid outer core of the Earth the transport of the angular momentum and internal heat occurs via thermal Rossby waves (Zhang et al. 2001; Kuang & Bloxham 1999). These waves been visualized in laboratory experiments in rotating liquid-filled spheres and concentric spherical shells (Zhang et al. 2001; Kuang & Bloxham 1999). The basic dynamical features of Rossby waves have been reproduced in a cylindrical annulus, a system much simpler than the spherical ones (Busse & Or 1986; Or & Busse 1987). For convection in a cylindrical annulus, the fluid motion is two-dimensional, and gravity is replaced by a centrifugal force, (Busse & Or 1986; Or & Busse 1987). Hide (1971) has suggested that the momentum and heat transport in the core might be influenced significantly by so-called bumps, which are heterogeneities on the mantle-core boundary. To model the effect of surface topography on the transport of momentum and energy in the liquid outer core of the Earth, Bell & Soward (1996), Herrmann & Busse (1998) and Westerburg & Busse (2001) have studied the nonlinear dynamics of thermal Rossby waves in a cylindrical annulus with azimuthally modulated height.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.8146E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.8146E"><span>On the roto-translatory internal motions of a three layer non-isobarycentric Earth model: a Lagrangian system approach</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Escapa, Alberto; Fukushima, Toshio</p> <p>2010-05-01</p> <p>The internal structure of numerous celestial bodies are well approximated by means of a three layer model composed of a solid external layer, which encloses a fluid layer containing a solid body. An analysis of the inner dynamics of this model can provide some constrains on its rheological characteristics; an information that in many situations is only accessible through this indirect way. In addition, the understanding of this kind of motions, especially of those associated with a rigid displacement (a rotation or a relative translation) of the solid layers, is of primary importance to establish with enough accuracy the definition of the terrestrial reference frames. In the Earth case, most approaches to this formidable problem rely on the numerical solution of the respective elastic field equations, once they have been projected on a set of spherical harmonics functions of a given degree. Due to its intrinsic nature these numerical methods do not provide by themselves much insight into the internal dynamics, hence the interest to develop simpler dynamical models that reproduces the main characteristics of the motion and allows obtaining analytical approximate solutions of the problem. To this aim, and as a first stage, we have considered the internal dynamics of a simple Earth model made up of a spherical rigid mantle, an inviscid, homogeneous fluid outer core and a spherical rigid inner core. Initially the barycenters of all the constituents are located at the same point (isobarycentric model) and the whole system rotates with constant angular velocity around the figure axis. When this situation is perturbed both the motions of the fluid and of the solid layers depart from the reference uniform rotation. However, following Busse (1974) we have assumed that the motion of the mantle is the same as in the unperturbed state, and that the inner core dynamics only suffers a variation of oscillatory nature in the translational motion of its barycenter. As a consequence of this relative motion, three characteristic proper modes appear: one in the direction of the figure axis (polar mode) and two orthogonal to it (equatorial modes). These modes are usually referred as Slichter triplet. In the case of the polar mode, Busse (1974) determined analytically its expression in an implicit way; later other authors have obtained by numerical methods the values of all the modes (e.g Rieutord 2002). These expressions differ substantially from the single degenerate mode existing for a non-rotating model, the differences arising from the roto-traslatory coupling of the system. To construct an analytical description of the motion of this non-isobarycentric Earth model we have approximated it by a Lagrangian system, inspired in the successful of this variational approach to tackle the rotational dynamics of isobarycentric Earth models (e.g. Moritz 1982, Getino and Ferrándiz 2001). In this way, the fluid flow is represented as the sum of a rigid motion part plus a potential motion part. In this way, the resulting dynamical system is described by means of nine generalized co-ordinates. Once constructed the kinetic energy of each layer of the Earth model and the potential energy due to the gravitational interaction of the spherical rigid inner core with the fluid, we form the Euler-Lagrange equations of the system which turn out to be non-linear. By assuming a small departure with respect to the steady rotation configuration we linearice the differential equations of the motion, deriving from them the analytical expressions of the Slichter triplet. These expressions are compared with the existing numerical ones, appearing some discrepancies between both approaches. They might be caused by neglecting the non-linear terms in the resolution of the equations or by an incomplete description of the fluid flow. However, the numerical values of the modes derived with this treatment show a great improvement with respect to the values obtained from performing simply a kinematical correction on the degenerate mode of a non-rotating model. Namely, the relative errors in the periods of the equatorial modes are reduced from 11.69% to 3.79% and from -6.04% to -1.91%, respectively. Acknowledgement.- AE's contribution was carried out thanks to a sabbatical leave from the University of Alicante at the National Astronomical Observatory of Japan (NAOJ), supported by the Spanish Ministerio de Educación, project PR2009-0379, within the Programa Nacional de Movilidad de Recursos Humanos I-D+i 2008-2011. The generous hospitality of the NAOJ staff is gratefully acknowledged. References Busse, F.H., J. Geophys. Res. 79, 753, 1974 Getino, J. and Ferrándiz, J. M., Mon. Not. R. Astron. Soc. 322, 785, 2001 Moritz, H., Bull. Géod., 56, 364, 1982 Rieutord, M., Phys. Earth Planet. Int., 131, 269, 2002</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70185547','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70185547"><span>A wireline piston core barrel for sampling cohesionless sand and gravel below the water table</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Zapico, Michael M.; Vales, Samuel; Cherry, John A.</p> <p>1987-01-01</p> <p>A coring device has been developed to obtain long and minimally disturbed samples of saturated cohesionless sand and gravel. The coring device, which includes a wireline and piston, was developed specifically for use during hollow-stem auger drilling but it also offers possibilities for cable tool and rotary drilling. The core barrel consists of an inner liner made of inexpensive aluminum or plastic tubing, a piston for core recovery, and an exterior steel housing that protects the liner when the core barrel is driven into the aquifer. The core barrel, which is approximately 1.6m (5.6 feet) long, is advanced ahead of the lead auger by hammering at the surface on drill rods that are attached to the core barrel. After the sampler has been driven 1.5m (5 feet), the drill rods are detached and a wireline is used to hoist the core barrel, with the sample contained in the aluminum or plastic liner, to the surface. A vacuum developed by the piston during the coring operation provides good recovery of both the sediment and aquifer fluids contained in the sediment. In the field the sample tubes can be easily split along their length for on-site inspection or they can be capped with the pore water fluids inside and transported to the laboratory. The cores are 5cm (2 inches) in diameter by 1.5m (5 feet) long. Core acquisition to depths of 35m (115 feet), with a recovery greater than 90 percent, has become routine in University of Waterloo aquifer studies. A large diameter (12.7cm [5 inch]) version has also been used successfully. Nearly continuous sample sequences from sand and gravel aquifers have been obtained for studies of sedimentology, hydraulic conductivity, hydrogeochemistry and microbiology.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160005401','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160005401"><span>Generalized Fluid System Simulation Program, Version 6.0</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Majumdar, A. K.; LeClair, A. C.; Moore, R.; Schallhorn, P. A.</p> <p>2016-01-01</p> <p>The Generalized Fluid System Simulation Program (GFSSP) is a general purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors, and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the 'point, drag, and click' method; the users can also run their models and post-process the results in the same environment. Two thermodynamic property programs (GASP/WASP and GASPAK) provide required thermodynamic and thermophysical properties for 36 fluids: helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, parahydrogen, water, kerosene (RP-1), isobutene, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, R-11, R-12, R-22, R-32, R-123, R-124, R-125, R-134A, R-152A, nitrogen trifluoride, ammonia, hydrogen peroxide, and air. The program also provides the options of using any incompressible fluid with constant density and viscosity or ideal gas. The users can also supply property tables for fluids that are not in the library. Twenty-four different resistance/source options are provided for modeling momentum sources or sinks in the branches. These options include pipe flow, flow through a restriction, noncircular duct, pipe flow with entrance and/or exit losses, thin sharp orifice, thick orifice, square edge reduction, square edge expansion, rotating annular duct, rotating radial duct, labyrinth seal, parallel plates, common fittings and valves, pump characteristics, pump power, valve with a given loss coefficient, Joule-Thompson device, control valve, heat exchanger core, parallel tube, and compressible orifice. The program has the provision of including additional resistance options through User Subroutines. GFSSP employs a finite volume formulation of mass, momentum, and energy conservation equations in conjunction with the thermodynamic equations of state for real fluids as well as energy conservation equations for the solid. The system of equations describing the fluid network is solved by a hybrid numerical method that is a combination of the Newton-Raphson and successive substitution methods. The application and verification of the code has been demonstrated through 30 example problems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910070176&hterms=nuclear+physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnuclear%2Bphysics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910070176&hterms=nuclear+physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnuclear%2Bphysics"><span>Ultrahigh temperature vapor core reactor-MHD system for space nuclear electric power</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maya, Isaac; Anghaie, Samim; Diaz, Nils J.; Dugan, Edward T.</p> <p>1991-01-01</p> <p>The conceptual design of a nuclear space power system based on the ultrahigh temperature vapor core reactor with MHD energy conversion is presented. This UF4 fueled gas core cavity reactor operates at 4000 K maximum core temperature and 40 atm. Materials experiments, conducted with UF4 up to 2200 K, demonstrate acceptable compatibility with tungsten-molybdenum-, and carbon-based materials. The supporting nuclear, heat transfer, fluid flow and MHD analysis, and fissioning plasma physics experiments are also discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820013812','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820013812"><span>Investigation of geomagnetic field forecasting and fluid dynamics of the core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benton, E. R. (Principal Investigator)</p> <p>1981-01-01</p> <p>The magnetic determination of the depth of the core-mantle boundary using MAGSAT data is discussed. Refinements to the approach of using the pole-strength of Earth to evaluate the radius of the Earth's core-mantle boundary are reported. The downward extrapolation through the electrically conducting mantle was reviewed. Estimates of an upper bound for the time required for Earth's liquid core to overturn completely are presented. High order analytic approximations to the unsigned magnetic flux crossing the Earth's surface are also presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996PhDT........47C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996PhDT........47C"><span>Fluid Motion and the Toroidal Magnetic Field Near the Top of Earth's Liquid Outer Core.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Celaya, Michael Augustine</p> <p></p> <p>This work considers two unresolved problems central to the study of Earth's deep interior: (1) What is the surface flow of the complete three dimensional motion sustaining the geomagnetic field in the fluid outer core? (2) How strong is the toroidal component of that field just beneath the mantle inside the core?. A solution of these problems is necessary to achieve even a basic understanding of magnetic field generation, and core-mantle interactions. Progress in solving (1) is made by extending previous attempts to resolve the core surface flow, and identifying obstacles which lead to distorted solutions. The extension relaxes the steady motions constraint. This permits more realistic solutions which should resemble more closely the real Earth flow. A difficulty with the assumption of steady flow is that if the real motion is unsteady, as it is likely to be, then steady models will suffer from aliasing. Aliased solutions can be highly corrupted. The effects of aliasing incurred through model underparametrization are explored. It is found that flow spectral energy must fall rapidly with increasing degree to escape aliasing's distortion. Damping does not appear to remedy the problem, but in fact obscures it by forcing the solution to converge upon a single, but possibly still aliased estimate. Inversions of a magnetic field model for unsteady motions, indicate steady flows are indeed aliased in time. By comparison, unsteady flows appear free of aliasing and show significant temporal variation, changing by about 30% of their magnitude over 20 years. However, it appears that noise in the high degree secular variation (SV) data used to determine the flow acts as a further impediment to solving (1). Damping is shown to be effective in removing noise, but only once aliasing is no longer a factor and noise is restricted to that part of the SV which makes only a small contribution to the solution. To solve (2) the radial component of Ohm's law is inverted for the toroidal field (B_{T }) near the top of the corp. The flow, obtained as a solution to (1), is treated as a known quantity, as is the poloidal field. Solutions are sought which minimize the difference between observed and predicted poloidal main field at Earth's surface. As in problem (1), aliasing in space and time stand as potential impediments to good resolution of the toroidal field. Steady degree 10 models of B_{T} are obtained which display convergence in space and time without damping. Poloidal field noise, as well as sensitivity to the flow model used in the inversions, limit resolution of toroidal field geometry. Nevertheless, estimates indicate the magnitude of B_{T } does not exceed 8times 10^ {-5}T, or about half that of the poloidal field near the core surface. Such a low value favors weak -field dynamo models but does not necessarily endorse a geostrophic force balance just beneath the mantle because partial_{r}B _{T} may be large enough to violate conditions required by geostrophy.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDM15006M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDM15006M"><span>Computational reconstruction and fluid dynamics of in vivo thrombi from the microcirculation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mirramezani, Mehran; Tomaiuolo, Maurizio; Stalker, Timothy; Shadden, Shawn</p> <p>2016-11-01</p> <p>Blood flow and mass transfer can have significant effects on clot growth, composition and stability during the hemostatic response. We integrate in vivo data with CFD to better understand transport processes during clot formation. By utilizing electron microscopy, we reconstructed the 3D thrombus structure formed after a penetrating laser injury in a mouse cremaster muscle. Random jammed packing is used to reconstruct the microenvironment of the platelet aggregate, with platelets modeled as ellipsoids. In our 3D model, Stokes flow is simulated to obtain the velocity field in the explicitly meshed gaps between platelets and the lumen surrounding the thrombus. Based on in vivo data, a clot is composed of a core of highly activated platelets covered by a shell of loosely adherent platelets. We studied the effects of clot size (thrombus growth), gap distribution (consolidation), and vessel blood flow rate on mean intrathrombus velocity. The results show that velocity is smaller in the core as compared to the shell, potentially enabling higher concentration of agonists in the core contributing to its activation. In addition, our results do not appear to be sensitive to the geometry of the platelets, but rather gap size plays more important role on intrathrombus velocity and transport.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S44A..06H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S44A..06H"><span>Ultrasonic Seismic Wave Elastic Moduli and Attenuation, Petro physical Models and Work Flows for Better Subsurface Imaging Related to Monitoring of Sequestrated Supercritical CO2 and Geothermal Energy Exploration</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harbert, W.; Delaney, D.; Mur, A. J.; Purcell, C.; Zorn, E.; Soong, Y.; Crandall, D.; Haljasmaa, I.</p> <p>2016-12-01</p> <p>To better understand the petrophysical response at ultrasonic frequencies in rhyolite and carbonate (relevant to CO2 storage and CO2 enhanced oil recovery) lithologies we conducted core analysis incorporating variation in temperature, effective pressure and pore filling fluid. Ultrasonic compressive and shear wave (VP, VS1 and VS2) velocities were measured allowing calculation of the Bulk modulus (K), Young's modulus (E), Lamè's first parameter (λ), Shear modulus (G), Poisson's ratio (ν), and P-wave modulus (M). In addition, from the ultrasonic waveform data collected, we employed the spectral ratio method to estimate the quality factor. Carbonate samples were tested dry, using atmospheric gas as the pore phase, and with deionized water, oil, and supercritical CO2. We observed that Qp was directly proportional to effective pressure in our rhyolite samples. In addition, we observed effects of core anisotropy on Qp, however this was not apparent in higher porosity samples. Increasing effective pressure seems to decrease the effects of ultrasonic P-wave anisotropy. Qp was inversely proportional to temperature, however this was not observed for higher porosity samples. Qp was highly dependent on the rock porosity. Higher porosity samples displayed significantly lower values of Qp. In our experiments we observed that ultrasonic wave scattering due to heterogeneities in the carbonate samples was dominant. Although we observed lower μρ values, trends in our data strongly agreed with the model proposed workers interpreting AVO trends in a LMR cross plot space. We found that μρ was proportional to temperature while λρ was temperature independent and that λρ-μρ trends were extremely dependent on porosity. Higher porosity results in lower values for both λρ and μρ. The presence of fluids causes a distinct shift in λρ values, an observation which could provide insight into subsurface exploration using amplitude variation with offset (AVO) classification. We present approaches to incorporate these laboratory results into well log calibrated MATLAB based Gassmann-Biot fluid substitution models incorporating compliant porosity, Thomsen parameters models that utilize orthorhombic velocity anisotropy to predict seismic responses.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMDI52B..04E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMDI52B..04E"><span>Questionable inheritance: What Processes on Planetesimals Mean for the Bulk Composition of the Earth</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elkins-Tanton, L. T.</p> <p>2015-12-01</p> <p>Interrogating Earth's interior is limited to indirect means, such as seismic or magnetic fields, and relies heavily on modeling. A large body of literature either attempts to constrain the composition of the deep mantle by mass balancing the Earth with a chondritic composition, or to demonstrate that the Earth does not have a chondritic composition. These models provide predictions for the composition and density of the ultra-low shear wave provinces and for the D" layer, among others, and compare their results to structures resulting from seismic studies. The bulk composition of the Earth, however, remains an open question. We now know that the planets accreted from embryos that were already differentiated. The complexity of processes that occurred on planetesimals and planetary embryos are just beginning to come to light. Heating by radiogenic 26Al likely produced waves of hydration and dehydration in planetesimals. These free fluids may have carried a wide range of volatiles, moving them from the interior to the lid, or even losing them to space. Simultaneously, the first free fluids may have reacted with metals, producing oxides or sulfides. Further heating is required to reduce these to metals and made core formation possible; or perhaps the earliest cores are not fully metallic. These planetesimals and the embryos they were growing into were subjected to a series of impacts. As the work of Asphaug and his group have demonstrated, some of these are accretionary impacts, and some are hit-and-run, or destructive impacts. These destructive impacts may have reduced the thickness of Mercury's mantle, and stripped the mantle off the metal asteroid Psyche. Where, then would the shattered silicates from such collisions go? Asphuag suggests that at least in part they are added to the growing terrestrial planets. If the planetesimals and planetary embryos were compositionally heterogeneous because of interior fluid and magma movement, then the silicates blown off them by impacts would not have a bulk chondritic composition. The growing planets would not then have a bulk chondritic composition. This talk will discuss the possible ramifications of this model and its application to bulk Earth models.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1191809-wellbore-cement-fracture-evolution-cementbasalt-caprock-interface-during-geologic-carbon-sequestration','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1191809-wellbore-cement-fracture-evolution-cementbasalt-caprock-interface-during-geologic-carbon-sequestration"><span>Wellbore cement fracture evolution at the cement–basalt caprock interface during geologic carbon sequestration</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jung, Hun Bok; Kabilan, Senthil; Carson, James P.</p> <p>2014-08-07</p> <p>Composite Portland cement-basalt caprock cores with fractures, as well as neat Portland cement columns, were prepared to understand the geochemical and geomechanical effects on the integrity of wellbores with defects during geologic carbon sequestration. The samples were reacted with CO2-saturated groundwater at 50 ºC and 10 MPa for 3 months under static conditions, while one cement-basalt core was subjected to mechanical stress at 2.7 MPa before the CO2 reaction. Micro-XRD and SEM-EDS data collected along the cement-basalt interface after 3-month reaction with CO2-saturated groundwater indicate that carbonation of cement matrix was extensive with the precipitation of calcite, aragonite, and vaterite,more » whereas the alteration of basalt caprock was minor. X-ray microtomography (XMT) provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. Computational fluid dynamics (CFD) modeling further revealed that this stress led to the increase in fluid flow and hence permeability. After the CO2-reaction, XMT images displayed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along the fracture located at the cement-basalt interface. The 3-D visualization and CFD modeling also showed that the precipitation of calcium carbonate within the cement fractures after the CO2-reaction resulted in the disconnection of cement fractures and permeability decrease. The permeability calculated based on CFD modeling was in agreement with the experimentally determined permeability. This study demonstrates that XMT imaging coupled with CFD modeling represent a powerful tool to visualize and quantify fracture evolution and permeability change in geologic materials and to predict their behavior during geologic carbon sequestration or hydraulic fracturing for shale gas production and enhanced geothermal systems.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014CG.....73....6B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014CG.....73....6B"><span>Numerical modeling of fluid and electrical currents through geometries based on synchrotron X-ray tomographic images of reservoir rocks using Avizo and COMSOL</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bird, M. B.; Butler, S. L.; Hawkes, C. D.; Kotzer, T.</p> <p>2014-12-01</p> <p>The use of numerical simulations to model physical processes occurring within subvolumes of rock samples that have been characterized using advanced 3D imaging techniques is becoming increasingly common. Not only do these simulations allow for the determination of macroscopic properties like hydraulic permeability and electrical formation factor, but they also allow the user to visualize processes taking place at the pore scale and they allow for multiple different processes to be simulated on the same geometry. Most efforts to date have used specialized research software for the purpose of simulations. In this contribution, we outline the steps taken to use commercial software Avizo to transform a 3D synchrotron X-ray-derived tomographic image of a rock core sample to an STL (STereoLithography) file which can be imported into the commercial multiphysics modeling package COMSOL. We demonstrate that the use of COMSOL to perform fluid and electrical current flow simulations through the pore spaces. The permeability and electrical formation factor of the sample are calculated and compared with laboratory-derived values and benchmark calculations. Although the simulation domains that we were able to model on a desk top computer were significantly smaller than representative elementary volumes, and we were able to establish Kozeny-Carman and Archie's Law trends on which laboratory measurements and previous benchmark solutions fall. The rock core samples include a Fountainebleau sandstone used for benchmarking and a marly dolostone sampled from a well in the Weyburn oil field of southeastern Saskatchewan, Canada. Such carbonates are known to have complicated pore structures compared with sandstones, yet we are able to calculate reasonable macroscopic properties. We discuss the computing resources required.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V31F..03B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V31F..03B"><span>Pore Pressure Distribution and Flank Instability in Hydrothermally Altered Stratovolcanoes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ball, J. L.; Taron, J.; Hurwitz, S.; Reid, M. E.</p> <p>2015-12-01</p> <p>Field and geophysical investigations of stratovolcanoes with long-lived hydrothermal systems commonly reveal that initially permeable regions (such as brecciated layers of pyroclastic material) can become both altered and water-bearing. Hydrothermal alteration in these regions, including clay formation, can turn them into low-permeability barriers to fluid flow, which could increase pore fluid pressures resulting in flank slope instability. We examined elevated pore pressure conditions using numerical models of hydrothermal flow in stratovolcanoes, informed by geophysical data about internal structures and deposits. Idealized radially symmetric meshes were developed based on cross-sectional profiles and alteration/permeability structures of Cascade Range stratovolcanoes. We used the OpenGeoSys model to simulate variably saturated conditions in volcanoes heated only by regional heat fluxes, as well as 650°C intrusions at two km depth below the surface. Meteoric recharge was estimated from precipitation rates in the Cascade Range. Preliminary results indicate zones of elevated pore pressures form: 1) where slopes are underlain by continuous low-permeability altered layers, or 2) when the edifice has an altered core with saturated, less permeable limbs. The first scenario might control shallow collapses on the slopes above the altered layers. The second could promote deeper flank collapses that are initially limited to the summit and upper slopes, but could progress to the core of an edifice. In both scenarios, pore pressures can be further elevated by shallow intrusions, or evolve over longer time scales under forcing from regional heat flux. Geometries without confining low-permeability layers do not show these pressure effects. Our initial scenarios use radially symmetric models, but we are also simulating hydrothermal flow under real 3D geometries with asymmetric subsurface structures (Mount Adams). Simulation results will be used to inform 3D slope-stability models.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP13A1065M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP13A1065M"><span>Unlocking the coral calcification process: Insights from boron isotope measurements and a skeletal growth model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mollica, N. R.; Guo, W.; Cohen, A. L.; Huang, K. F.; Foster, G. L.; Donald, H.; Solow, A.</p> <p>2017-12-01</p> <p>Carbonate skeletons of scleractinian corals are important archives of ocean climate and environmental change. However, corals don't accrete their skeletons directly from ambient seawater, but from a calcifying fluid whose composition is strongly regulated. There is mounting evidence that the carbonate chemistry of this calcifying fluid significantly impacts the amount of carbonate the coral can precipitate, which in turn affects the geochemical composition of the skeleton produced. However the mechanistic link between calcifying fluid (cf) chemistry, particularly the up-regulation of pHcf and thereby aragonite saturation state (Ωcf), and coral calcification is not well understood. We explored this link by combining boron isotope measurements with in situ measurements of seawater temperature, salinity, and DIC to estimate Ωcf of nine Porites corals from four Pacific reefs. Associated calcification rates were quantified for each core via CT scanning. We do not observe a relationship between calcification rates and Ωcf or Ωsw. Instead, when we deconvolve calcification into linear extension and skeletal density, a significant correlation is observed between density and Ωcf, and also Ωsw while extension does not correlate with either. These observations are consistent with the two-step model of coral calcification, in which skeleton is secreted in two distinct phases: vertical extension creating new skeletal elements, followed by lateral thickening of existing elements that are covered by living tissue. We developed a numerical model of Porites skeletal growth that builds on this two-step model and links skeletal density with the external seawater environment via its influence on the chemistry of coral calcifying fluid. We validated the model using existing coral skeletal datasets from six Porites species collected across five reef sites, and quantified the effects of each seawater parameter (e.g. temperature, pH, DIC) on skeletal density. Our findings illustrate the sensitivity of the second phase of coral calcification to the carbonate chemistry of the calcifying fluid, and support previous coral proxy system modelling efforts by validating the two-step growth model on annual and seasonal scales.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......216B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......216B"><span>Theory and Simulations of Incomplete Reconnection During Sawteeth Due to Diamagnetic Effects</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beidler, Matthew Thomas</p> <p></p> <p>Tokamaks use magnetic fields to confine plasmas to achieve fusion; they are the leading approach proposed for the widespread production of fusion energy. The sawtooth crash in tokamaks limits the core temperature, adversely impacts confinement, and seeds disruptions. Adequate knowledge of the physics governing the sawtooth crash and a predictive capability of its ramifications has been elusive, including an understanding of incomplete reconnection, i.e., why sawteeth often cease prematurely before processing all available magnetic flux. In this dissertation, we introduce a model for incomplete reconnection in sawtooth crashes resulting from increasing diamagnetic effects in the nonlinear phase of magnetic reconnection. Physically, the reconnection inflow self-consistently convects the high pressure core of a tokamak toward the q=1 rational surface, thereby increasing the pressure gradient at the reconnection site. If the pressure gradient at the rational surface becomes large enough due to the self-consistent evolution, incomplete reconnection will occur due to diamagnetic effects becoming large enough to suppress reconnection. Predictions of this model are borne out in large-scale proof-of-principle two-fluid simulations of reconnection in a 2D slab geometry and are also consistent with data from the Mega Ampere Spherical Tokamak (MAST). Additionally, we present simulations from the 3D extended-MHD code M3D-C1 used to study the sawtooth crash in a 3D toroidal geometry for resistive-MHD and two-fluid models. This is the first study in a 3D tokamak geometry to show that the inclusion of two-fluid physics in the model equations is essential for recovering timescales more closely in line with experimental results compared to resistive-MHD and contrast the dynamics in the two models. We use a novel approach to sample the data in the plane of reconnection perpendicular to the (m,n)=(1,1) mode to carefully assess the reconnection physics. Using local measures of reconnection, we find that it is much faster in the two-fluid simulations, consistent with expectations based on global measures. By sampling data in the reconnection plane, we present the first observation of the quadrupole out-of-plane magnetic field appearing during sawtooth reconnection with the Hall term. We also explore how reconnection as viewed in the reconnection plane varies toroidally, which affects the symmetry of the reconnection geometry and the local diamagnetic effects. We expect our results to be useful for transport modeling in tokamaks, predicting energetic alpha-particle confinement, and assessing how sawteeth trigger disruptions. Since the model only depends on local diamagnetic and reconnection physics, it is machine independent, and should apply both to existing tokamaks and future ones such as ITER.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17629529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17629529"><span>Manipulations of core temperatures in ischemia-reperfusion lung injury in rabbits.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Hung; Huang, Kun-Lun; Li, Min-Hui; Hsu, Ching-Wang; Tsai, Shih-Hung; Chu, Shi-Jye</p> <p>2008-01-01</p> <p>The present study was designed to determine the effect of various core temperatures on acute lung injury induced by ischemia-reperfusion (I/R) in our isolated rabbit lung model. Typical acute lung injury was successfully induced by 30 min of ischemia followed by 90 min of reperfusion observation. The I/R elicited a significant increase in pulmonary arterial pressure, microvascular permeability (measured by using the capillary filtration coefficient, Kfc), Delta Kfc ratio, lung weight gain and the protein concentration of the bronchoalveolar lavage fluid. Mild hypothermia significantly attenuated acute lung injury induced by I/R, all parameters having decreased significantly (p<0.05); conversely, mild hyperthermia did not further exacerbate acute lung injury. These experimental data suggest that mild hypothermia significantly ameliorated acute lung injury induced by ischemia-reperfusion in rabbits.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.9431T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.9431T"><span>Influence of Mercury</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tackley, P. J.; Aurnou, J. M.; Aubert, J.</p> <p>2009-04-01</p> <p>Due to the absence of an atmosphere and proximity to the Sun, Mercury's surface temperature varies laterally by several 100s K, even when averaged over long time periods. The dominant variation in time-averaged surface T occurs from pole to equator (~225 K) [1]. The resonant relationship between Mercury's orbit and rotation results in a smaller longitudinal variation (~100 K) [1]. Here we demonstrate, using models of mantle convection in a 3-D spherical shell, that this stationary lateral variation in surface temperature has a small but significant influence on mantle convection and on the lateral variation of heat flux across the core-mantle boundary (CMB). We evaluate the possible observational signature of this laterally-varying convection in terms of boundary topography, stress distribution, gravity and moment of inertia tensor. We furthermore test whether the lateral variation in CMB flux is capable of driving a thermal wind dynamo, i.e., weak dynamo action with no internally-driven core convective motions. For Mercury's mantle we assume a dry olivine rheology including both diffusion creep and disclocation creep with rheological parameters such as activation energy and volume taken from the synthesis of [2]. We assume decaying radiogenic heat sources with the same concentration as in the bulk silicate Earth, and a parameterised model of core cooling. The models are run for 4.5 Ga from a relatively hot initial state with random initial perturbations. We use the code StagYY, which uses a finite-volume discretization on a spherical yin-yang grid and a multigrid solver [3]. Results in spherical axisymmetric geometry, compare a case with constant surface temperature to one with a latitude-dependent surface temperature. The system forms about 3 convection cells from pole to equator. Although the results look similar to first order, in the latitude-dependent case the convection is noticably more sluggish and colder towards the pole. In CMB flux, both cases display large oscillations due to convection cells. A pole-to-equator trend is superimposed on this for the case with laterally-varying surface temperature. Although the amplitude of this long-wavelength variation is smaller than that of the within-cell variation, its long-wavelength nature might be effective in driving thermal winds in the core. Results in a full 3-D spherical shell indicate that convection adopts a cellular structure with a polygonal network of downwellings and plume-like upwellings, as is usually obtained for stagnant lid convection, for example, in the recent 3-D spherical Mercury models of [4]. This is in notable contrast to the models of [5], in which linear upwellings were obtained. This difference could be because the initial perturbations used by [5] used a small number of low-order spherical harmonics, i.e., a long-wavelength pattern with particular symmetries, whereas our initial perturbations are random white noise. The origin of this difference requires further investigation. The pattern of CMB heat flux shows a strong l=2, m=0 pattern, again with superimposed small-scale variations due to convection cells. The surface geoid displays an very dominant (2,0) pattern, which would be a strong diagnostic of this behaviour. These models are being further analysed for boundary topography and stress distribution. Models of planetary dynamos have traditionally depended upon the concept that secular cooling and internal radioactive decay are responsible for genererating convective fluid motions within the core [e.g. 6]. Some models, of Earth's dynamo in particular, also include thermal winds --shear flows driven by heat flux variations along the core-mantle boundary -- that modify the dynamo process [e.g. 7]. We have now shown, following the work of [8], that thermal winds themselves are capable of driving dynamo action in planetary cores (Fig. 4). In fully self-consistent, three-dimensional models, we find that thermal wind dynamos do not require a net heat flux to emanate from the core and can operate even when the core fluid is neutrally stratified. In these models, the dynamo is powered externally by thermal energy stored in the mantle. This dynamo mechanism can occur on planetary bodies, such as Mercury, which are likely to have weak net heat fluxes from their cores but possess significant core-mantle boundary heat flux variations (Figures 1 - 3). We plan to use the pattern of CMB heat flux from the mantle models as a boundary condition for core models, in order to determine the feasibility of thermal wind dynamo action occurring in Mercury's core. References [1] Aharonson, O., et al. (2004) EPSL, 218, 261-268. [2] Karato, S. and Wu, P. (1993) Sci., 260, 771-778. [3] Tackley, P. J. (2008) PEPI, doi: 10.1016/j.pepi.2008.08.005.. [4] Breuer, D. et al. (2007) Sp. Sci. Rev., 132, 229-260. [5] King, S. D. (2008) Nature Geoscience, 1, 229-232. [5] Heimpel, M. H. et al. (2005) EPSL, 236, 542-557. [7] Willis, A., et al. (2007) PEPI, 165, 83-92. [8] Sarson, G., (2003) PRSL A, 459, 1241-1259. [9] Aubert, J., et al. (2008) GJI, 172, 945-956.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMDI13C..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMDI13C..05H"><span>Partial Melting in the Inner Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernlund, J. W.</p> <p>2014-12-01</p> <p>The inner core boundary (ICB) is often considered to be permeable to flow, because solid iron could melt as it upwells across the ICB. Such a mechanism has been proposed to accompany inner core convective processes (including translation from a freezing to melting hemisphere), and has also been invoked to explain the formation of a dense Fe-rich liquid F-layer above the ICB. However, the conceptions of ICB melting invoked thus far are extremely simplistic, and neglect the many lessons learned from melting in other geological contexts. Owing to some degree of solid solution in relatively incompatible light alloys in solid iron, the onset of melting in the inner core will likely occur as a partial melt, with the liquid being enriched in these light alloys relative to the co-existing solid. Such a partial melt is then subject to upward migration/percolation out of the solid matrix owing to the buoyancy of melt relative to solid. Removal of melt and viscous compaction of the pore space results in an iron-enriched dense solid, whose negative buoyancy will oppose whatever buoyancy forces initially gave rise to upwelling. Either the negative buoyancy will balance these other forces and cause upwelling to cease, or else the solid will become so depleted in light alloys that it is unable to undergo further melting. Thus a proper accounting of partial melting results in a very different melting regime in the inner core, and suppression of upwelling across the ICB. Any fluid that is able to escape into the outer core from inner core partial melting will likely be buoyant because in order to be a melt it should be enriched in incompatiable alloys relative to whatever is freezing at the ICB. Therefore inner core melting is unlikely to contribute to the formation of an F-layer, but instead will tend to de-stabilize it. I will present models that illustrate these processes, and propose that the F-layer is a relic of incomplete mixing of the core during Earth's final stages of formation. Such models imply that the inner core may be somewhat older than models in which it crystallizes from a homogeneous outer core, although without any significant benefits for driving the geodynamo.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/4273851','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4273851"><span>ENGINEERING TEST REACTOR</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>De Boisblanc, D.R.; Thomas, M.E.; Jones, R.M.; Hanson, G.H.</p> <p>1958-10-21</p> <p>Heterogeneous reactors of the type which is both cooled and moderated by the same fluid, preferably water, and employs highly enriched fuel are reported. In this design, an inner pressure vessel is located within a main outer pressure vessel. The reactor core and its surrounding reflector are disposed in the inner pressure vessel which in turn is surrounded by a thermal shield, Coolant fluid enters the main pressure vessel, fiows downward into the inner vessel where it passes through the core containing tbe fissionable fuel assemblies and control rods, through the reflector, thence out through the bottom of the inner vessel and up past the thermal shield to the discharge port in the main vessel. The fuel assemblles are arranged in the core in the form of a cross having an opening extending therethrough to serve as a high fast flux test facility.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22415946-structure-thermodynamics-core-softened-models-alcohols','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22415946-structure-thermodynamics-core-softened-models-alcohols"><span>Structure and thermodynamics of core-softened models for alcohols</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Munaò, Gianmarco, E-mail: gmunao@unime.it; Urbic, Tomaz</p> <p></p> <p>The phase behavior and the fluid structure of coarse-grain models for alcohols are studied by means of reference interaction site model (RISM) theory and Monte Carlo simulations. Specifically, we model ethanol and 1-propanol as linear rigid chains constituted by three (trimers) and four (tetramers) partially fused spheres, respectively. Thermodynamic properties of these models are examined in the RISM context, by employing closed formulæ for the calculation of free energy and pressure. Gas-liquid coexistence curves for trimers and tetramers are reported and compared with already existing data for a dimer model of methanol. Critical temperatures slightly increase with the number ofmore » CH{sub 2} groups in the chain, while critical pressures and densities decrease. Such a behavior qualitatively reproduces the trend observed in experiments on methanol, ethanol, and 1-propanol and suggests that our coarse-grain models, despite their simplicity, can reproduce the essential features of the phase behavior of such alcohols. The fluid structure of these models is investigated by computing radial distribution function g{sub ij}(r) and static structure factor S{sub ij}(k); the latter shows the presence of a low−k peak at intermediate-high packing fractions and low temperatures, suggesting the presence of aggregates for both trimers and tetramers.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70015303','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70015303"><span>Constraints from fluid inclusions on sulfide precipitation mechanisms and ore fluid migration in the Viburnum Trend lead district, Missouri</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rowan, E.L.; Leach, D.L.</p> <p>1989-01-01</p> <p>Homogenization temperatures and freezing point depressions were determined for fluid inclusions in Bonneterre Dolomite-hosted dolomite cements in mine samples, as well as drill core from up to 13 km outside of the district. A well-defined cathodoluminescent zonation distinguishes dolomite growth zones as older or younger than main-stage mineralization. Homogenization temperatures and salinities in samples from mines are not systematically different from those of samples outside of the district. The absence of a significant, recognizable decrease in temperature either vertically within the section or east-west across the district, coupled with the minor amount of silica in the district, argues against cooling as a primary cause of sulfide precipitation. In a reduced sulfur mineralization model with Pb carried as chloride complexes, dilution is also a possible sulfide precipitation mechanism. The difference in Pb solubility in the extremes of the chloride concentration range, 3.9 vs. 5.9 molal, reaches 1 ppm only for pH values below approximately 4.5. The distribution of warm inclusions beyond the Viburnum Trend district implies that fluid migration was regional in scale. Elevated temperatures observed in fluid inclusions at shallow stratigraphic depths are consistent with a gravity flow hydrologic system characterized by rapid flow rates and the capacity for advective heat transport. -from Authors</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27203125','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27203125"><span>Numerical Simulation of Permeability Change in Wellbore Cement Fractures after Geomechanical Stress and Geochemical Reactions Using X-ray Computed Tomography Imaging.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kabilan, Senthil; Jung, Hun Bok; Kuprat, Andrew P; Beck, Anthon N; Varga, Tamas; Fernandez, Carlos A; Um, Wooyong</p> <p>2016-06-21</p> <p>X-ray microtomography (XMT) imaging combined with three-dimensional (3D) computational fluid dynamics (CFD) modeling technique was used to study the effect of geochemical and geomechanical processes on fracture permeability in composite Portland cement-basalt caprock core samples. The effect of fluid density and viscosity and two different pressure gradient conditions on fracture permeability was numerically studied by using fluids with varying density and viscosity and simulating two different pressure gradient conditions. After the application of geomechanical stress but before CO2-reaction, CFD revealed fluid flow increase, which resulted in increased fracture permeability. After CO2-reaction, XMT images displayed preferential precipitation of calcium carbonate within the fractures in the cement matrix and less precipitation in fractures located at the cement-basalt interface. CFD estimated changes in flow profile and differences in absolute values of flow velocity due to different pressure gradients. CFD was able to highlight the profound effect of fluid viscosity on velocity profile and fracture permeability. This study demonstrates the applicability of XMT imaging and CFD as powerful tools for characterizing the hydraulic properties of fractures in a number of applications like geologic carbon sequestration and storage, hydraulic fracturing for shale gas production, and enhanced geothermal systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1290386-numerical-simulation-permeability-change-wellbore-cement-fractures-after-geomechanical-stress-geochemical-reactions-using-ray-computed-tomography-imaging','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1290386-numerical-simulation-permeability-change-wellbore-cement-fractures-after-geomechanical-stress-geochemical-reactions-using-ray-computed-tomography-imaging"><span>Numerical Simulation of Permeability Change in Wellbore Cement Fractures after Geomechanical Stress and Geochemical Reactions Using X-ray Computed Tomography Imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kabilan, Senthil; Jung, Hun Bok; Kuprat, Andrew P.</p> <p></p> <p>X-ray microtomography (XMT) imaging combined with a three-dimensional (3D) computational fluid dynamics (CFD) modeling technique was used to study the effect of geochemical and geomechanical processes on fracture properties in composite Portland cement–basalt caprock core samples. The effect of fluid properties and flow conditions on fracture permeability was numerically studied by using fluids with varying physical properties and simulating different pressure conditions. CFD revealed that the application of geomechanical stress led to increased fluid flow, which resulted in increased fracture permeability. After CO2-reaction, XMT images displayed preferential precipitation of calcium carbonate within the fractures in the cement matrix and lessmore » precipitation in fractures located at the cement–basalt interface. CFD predicted changes in flow characteristics and differences in absolute values of flow properties due to different pressure gradients. CFD was able to highlight the profound effect of fluid properties on flow characteristics and hydraulic properties of fractures. This study demonstrates the applicability of XMT imaging and CFD as powerful tools for characterizing the hydraulic properties of fractures in a number of applications like geologic carbon sequestration and storage, hydraulic fracturing for shale gas production, and enhanced geothermal systems.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RScI...89d5107M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RScI...89d5107M"><span>Design and implementation of a shearing apparatus for the experimental study of shear displacement in rocks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, Johnathan; Crandall, Dustin; Gill, Magdalena; Brown, Sarah; Tennant, Bryan</p> <p>2018-04-01</p> <p>Fluid flow in the subsurface is not well understood in the context of "impermeable" geologic media. This is especially true of formations that have undergone significant stress fluctuations due to injection or withdrawal of fluids that alters the localized pressure regime. When the pressure regime is altered, these formations, which are often already fractured, move via shear to reduce the imbalance in the stress state. While this process is known to happen, the evolution of these fractures and their effects on fluid transport are still relatively unknown. Numerous simulation and several experimental studies have been performed that characterize the relationship between shearing and permeability in fractures; while many of these studies utilize measurements of fluid flow or the starting and ending geometries of the fracture to characterize shear, they do not characterize the intermediate stages during shear. We present an experimental apparatus based on slight modifications to a commonly available Hassler core holder that allows for shearing of rocks, while measuring the hydraulic and mechanical changes to geomaterials during intermediate steps. The core holder modification employs the use of semi-circular end caps and structural supports for the confining membrane that allow for free movement of the sheared material while preventing membrane collapse. By integrating this modified core holder with a computed tomography scanner, we show a new methodology for understanding the interdependent behavior between fracture structure and flow properties during intermediate steps in shearing. We include a case study of this device function which is shown here through shearing of a fractured shale core and simultaneous observation of the mechanical changes and evolution of the hydraulic properties during shearing.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29716362','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29716362"><span>Design and implementation of a shearing apparatus for the experimental study of shear displacement in rocks.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moore, Johnathan; Crandall, Dustin; Gill, Magdalena; Brown, Sarah; Tennant, Bryan</p> <p>2018-04-01</p> <p>Fluid flow in the subsurface is not well understood in the context of "impermeable" geologic media. This is especially true of formations that have undergone significant stress fluctuations due to injection or withdrawal of fluids that alters the localized pressure regime. When the pressure regime is altered, these formations, which are often already fractured, move via shear to reduce the imbalance in the stress state. While this process is known to happen, the evolution of these fractures and their effects on fluid transport are still relatively unknown. Numerous simulation and several experimental studies have been performed that characterize the relationship between shearing and permeability in fractures; while many of these studies utilize measurements of fluid flow or the starting and ending geometries of the fracture to characterize shear, they do not characterize the intermediate stages during shear. We present an experimental apparatus based on slight modifications to a commonly available Hassler core holder that allows for shearing of rocks, while measuring the hydraulic and mechanical changes to geomaterials during intermediate steps. The core holder modification employs the use of semi-circular end caps and structural supports for the confining membrane that allow for free movement of the sheared material while preventing membrane collapse. By integrating this modified core holder with a computed tomography scanner, we show a new methodology for understanding the interdependent behavior between fracture structure and flow properties during intermediate steps in shearing. We include a case study of this device function which is shown here through shearing of a fractured shale core and simultaneous observation of the mechanical changes and evolution of the hydraulic properties during shearing.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29283916','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29283916"><span>Heating and Cooling Rates With an Esophageal Heat Exchange System.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kalasbail, Prathima; Makarova, Natalya; Garrett, Frank; Sessler, Daniel I</p> <p>2018-04-01</p> <p>The Esophageal Cooling Device circulates warm or cool water through an esophageal heat exchanger, but warming and cooling efficacy in patients remains unknown. We therefore determined heat exchange rates during warming and cooling. Nineteen patients completed the trial. All had general endotracheal anesthesia for nonthoracic surgery. Intraoperative heat transfer was measured during cooling (exchanger fluid at 7°C) and warming (fluid at 42°C). Each was evaluated for 30 minutes, with the initial condition determined randomly, starting at least 40 minutes after induction of anesthesia. Heat transfer rate was estimated from fluid flow through the esophageal heat exchanger and inflow and outflow temperatures. Core temperature was estimated from a zero-heat-flux thermometer positioned on the forehead. Mean heat transfer rate during warming was 18 (95% confidence interval, 16-20) W, which increased core temperature at a rate of 0.5°C/h ± 0.6°C/h (mean ± standard deviation). During cooling, mean heat transfer rate was -53 (-59 to -48) W, which decreased core temperature at a rate of 0.9°C/h ± 0.9°C/h. Esophageal warming transferred 18 W which is considerably less than the 80 W reported with lower or upper body forced-air covers. However, esophageal warming can be used to supplement surface warming or provide warming in cases not amenable to surface warming. Esophageal cooling transferred more than twice as much heat as warming, consequent to the much larger difference between core and circulating fluid temperature with cooling (29°C) than warming (6°C). Esophageal cooling extracts less heat than endovascular catheters but can be used to supplement catheter-based cooling or possibly replace them in appropriate patients.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMDI33B0408J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMDI33B0408J"><span>A two-pronged approach to detecting ICB Stoneley modes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jasperson, H. A.; Ye, J.; Shi, J.; De Hoop, M. V.</p> <p>2017-12-01</p> <p>Stoneley modes are special kinds of normal modes that are confined to the boundary between a fluid layer and a solid layer inside the Earth. Thus, these modes theoretically occur at the core-mantle boundary (CMB) and inner core boundary (ICB). CMB Stoneley modes were identified in observational data by Koelemeijer, et al. in 2013, but ICB Stoneley modes have remained relatively unexplored. Here we use a joint numerical and data-driven approach to identify ICB Stoneley modes from the deep 2013 Mw 8.3 Sea of Okhotsk earthquake. For the data-driven portion, we use 50 stacked traces from the USArray to identify potential occurrences of ICB Stoneley modes. Next, we verify each occurrence by comparing the spectrum to its equivalent from the shallow 2011 Mw 9.1 Tohoku earthquake. We also develop a novel computational approach to compute normal modes in a spherically symmetric non-rotating Earth building on the work of Wiggins (1976) and Buland and Gilbert (1984). We successfully resolve the clustering eigenvalue problem with non-orthogonal eigenfunctions from which Mineos suffers. By choosing the displacement/pressure formulation in the fluid outer core and handling boundary conditions properly, we remarkably project out the essential spectrum and provide the correct point spectrum. The utilization of weak variational form to perform the Rayleigh-Ritz procedure contributes to preserving the high accuracy across the solid-fluid boundary, which makes it possible to capture Stoneley modes' exponentially decaying behavior across the solid-fluid boundary, leading to more accurate and reliable eigenvalues and eigenfunctions. This allows us to compare the observation data and numerical computations. With this approach, we eliminate false signals from consideration, leaving only true ICB Stoneley mode peaks. In the future, information from these modes can be used to study the properties of the ICB and inner core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B11B1672G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B11B1672G"><span>Biogeochemical interactions between of coal mine water and gas well cement</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gulliver, D. M.; Gardiner, J. B.; Kutchko, B. G.; Hakala, A.; Spaulding, R.; Tkach, M. K.; Ross, D.</p> <p>2017-12-01</p> <p>Unconventional natural gas wells drilled in Northern Appalachia often pass through abandoned coal mines before reaching the Marcellus or Utica formations. Biogeochemical interactions between coal mine waters and gas well cements have the potential to alter the cement and compromise its sealing integrity. This study investigates the mineralogical, geochemical, and microbial changes of cement cores exposed to natural coal mine waters. Static reactors with Class H Portland cement cores and water samples from an abandoned bituminous Pittsburgh coal mine simulated the cement-fluid interactions at relevant temperature for time periods of 1, 2, 4, and 6 weeks. Fluids were analyzed for cation and anion concentrations and extracted DNA was analyzed by 16S rRNA gene sequencing and shotgun sequencing. Cement core material was evaluated via scanning electron microscope. Results suggest that the sampled coal mine water altered the permeability and matrix mineralogy of the cement cores. Scanning electron microscope images display an increase in mineral precipitates inside the cement matrix over the course of the experiment. Chemistry results from the reaction vessels' effluent waters display decreases in dissolved calcium, iron, silica, chloride, and sulfate. The microbial community decreased in diversity over the 6-week experiment, with Hydrogenophaga emerging as dominant. These results provide insight in the complex microbial-fluid-mineral interactions of these environments. This study begins to characterize the rarely documented biogeochemical impacts that coal waters may have on unconventional gas well integrity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss028e048923.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss028e048923.html"><span>iss028e048923</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-13</p> <p>ISS028-E-048923 (13 Sept. 2011) --- Japan Aerospace Exploration Agency astronaut Satoshi Furukawa, Expedition 28 flight engineer, works with the Fluid Physics Experiment Facility/Marangoni Surface (FPEF MS) Core hardware in the Kibo laboratory of the International Space Station. The Marangoni convection experiment in the FPEF examines fluid tension flow in micro-G.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss021e020299.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss021e020299.html"><span>Williams working on the JAXA MS (Marangoni Surface) Experiment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2009-11-05</p> <p>ISS021-E-020299 (5 Nov. 2009) --- NASA astronaut Jeffrey Williams, Expedition 21 flight engineer, works with Fluid Physics Experiment Facility/Marangoni Surface (FPEF MS) Core hardware in the Kibo laboratory of the International Space Station. The Marangoni convection experiment in the FPEF examines fluid tension flow in micro-G.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol2/pdf/CFR-2013-title30-vol2-sec250-490.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title30-vol2/pdf/CFR-2013-title30-vol2-sec250-490.pdf"><span>30 CFR 250.490 - Hydrogen sulfide.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... absence of H2S has been confirmed. Well-control fluid means drilling mud and completion or workover fluid... information such as geologic and geophysical data and correlations, well logs, formation tests, cores and... concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect personnel from SO2; and (21...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol2/pdf/CFR-2014-title30-vol2-sec250-490.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title30-vol2/pdf/CFR-2014-title30-vol2-sec250-490.pdf"><span>30 CFR 250.490 - Hydrogen sulfide.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... absence of H2S has been confirmed. Well-control fluid means drilling mud and completion or workover fluid... information such as geologic and geophysical data and correlations, well logs, formation tests, cores and... concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect personnel from SO2; and (21...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol2/pdf/CFR-2012-title30-vol2-sec250-490.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title30-vol2/pdf/CFR-2012-title30-vol2-sec250-490.pdf"><span>30 CFR 250.490 - Hydrogen sulfide.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... absence of H2S has been confirmed. Well-control fluid means drilling mud and completion or workover fluid... information such as geologic and geophysical data and correlations, well logs, formation tests, cores and... concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect personnel from SO2; and (21...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol2/pdf/CFR-2011-title30-vol2-sec250-490.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol2/pdf/CFR-2011-title30-vol2-sec250-490.pdf"><span>30 CFR 250.490 - Hydrogen sulfide.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... where neither the presence nor absence of H2S has been confirmed. Well-control fluid means drilling mud..., well logs, formation tests, cores and analysis of formation fluids; and (4) Submit a request for... initiate when the SO2 concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015478','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015478"><span>Integrated Structural/Acoustic Modeling of Heterogeneous Panels</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bednarcyk, Brett, A.; Aboudi, Jacob; Arnold, Steven, M.; Pennline, James, A.</p> <p>2012-01-01</p> <p>A model for the dynamic response of heterogeneous media is presented. A given medium is discretized into a number of subvolumes, each of which may contain an elastic anisotropic material, void, or fluid, and time-dependent boundary conditions are applied to simulate impact or incident pressure waves. The full time-dependent displacement and stress response throughout the medium is then determined via an explicit solution procedure. The model is applied to simulate the coupled structural/acoustic response of foam core sandwich panels as well as aluminum panels with foam inserts. Emphasis is placed on the acoustic absorption performance of the panels versus weight and the effects of the arrangement of the materials and incident wave frequency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.B21G0497K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.B21G0497K"><span>Gas Migration Processes through the Gas Hydrate Stability Zone at Four-Way Closure Ridge Offshore SW Taiwan</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kunath, P.; Chi, W. C.; Berndt, C.; Liu, C. S.</p> <p>2016-12-01</p> <p>We have used 3D P-Cable seismic data from Four-Way-Closure Ridge, a NW-SE trending anticlinal ridge within the lower slope domain of accretionary wedge, to investigate the geological constraints influencing the fluid migration pattern in the shallow marine sediments. In the seismic data, fluid migration feature manifests itself as high reflection layers of dipping strata, which originate underneath a bottom simulating reflector (BSR) and extend towards the seafloor. Shoaling of the BSR near fluid migration pathways indicates a focused fluid flux, perturbing the temperature field. Furthermore, seafloor video footage confirmed the presence of recent methane seepage above seismically imaged fluid migration pathways. We plan to test two hypotheses for the occurrence of these fluid migration pathways: 1) the extensional regime under the anticlinal ridge crest caused the initiation of localized fault zones, acting as fluid conduits in the gas hydrate stability zone (GHSZ). 2) sediment deformation induced by focused fluid flow and massive growth and dissolution of gas hydrate, similar to processes controlling the evolution of pockmarks on the Nigerian continental margin. We suggest that these processes may be responsible for the formation of a massive hydrate core in the crest of the anticline, as inferred from other geophysical datasets. Triggering process for fluid migration cannot be clearly defined. However, the existence of blind thrust faults may help to advect deep-seated fluids. This may be augmented by biogenic production of shallow gas underneath the ridge, where the excess of gas enables the coexistence of gas, water, and gas hydrate within the GHSZ. Fluid migration structures may exists because of the buoyancy of gas-bearing fluids. This study shows a potential model on how gas-bearing fluids migrate upward towards structural highs, which might occur in other anticlinal structures around the world. Keywords: P-Cable, gas-hydrate, fluid flow, fault-related fold, methane seepage</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/894784','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/894784"><span>Modelling of Field-Reversed Configuration Experiment with Large Safety Factor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Steinhauer, L; Guo, H; Hoffman, A</p> <p>2005-11-28</p> <p>The Translation-Confinement-Sustainment facility has been operated in the 'translation-formation' mode in which a plasma is ejected at high-speed from a {theta}-pinch-like source into a confinement chamber where it settles into a field-reversed-configuration state. Measurements of the poloidal and toroidal field have been the basis of modeling to infer the safety factor. It is found that the edge safety factor exceeds two, and that there is strong forward magnetic shear. The high-q arises because the large elongation compensates for the modest ratio of toroidal-to-poloidal field in the plasma. This is the first known instance of a very high-{beta} plasma with amore » safety factor greater than unity. Two-fluid modeling of the measurements also indicate several other significant features: a broad 'transition layer' at the plasma boundary with probable line-tying effects, complex high-speed flows, and the appearance of a two-fluid minimum-energy state in the plasma core. All these features may contribute to both the stability and good confinement of the plasma.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22598996-hydrodynamic-structure-boundary-layers-rotating-cylindrical-cavity-radial-inflow','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22598996-hydrodynamic-structure-boundary-layers-rotating-cylindrical-cavity-radial-inflow"><span>Hydrodynamic structure of the boundary layers in a rotating cylindrical cavity with radial inflow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Herrmann-Priesnitz, Benjamín, E-mail: bherrman@ing.uchile.cl; Torres, Diego A.; Advanced Mining Technology Center, Universidad de Chile, Av. Tupper 2007, Santiago</p> <p></p> <p>A flow model is formulated to investigate the hydrodynamic structure of the boundary layers of incompressible fluid in a rotating cylindrical cavity with steady radial inflow. The model considers mass and momentum transfer coupled between boundary layers and an inviscid core region. Dimensionless equations of motion are solved using integral methods and a space-marching technique. As the fluid moves radially inward, entraining boundary layers develop which can either meet or become non-entraining. Pressure and wall shear stress distributions, as well as velocity profiles predicted by the model, are compared to numerical simulations using the software OpenFOAM. Hydrodynamic structure of themore » boundary layers is governed by a Reynolds number, Re, a Rossby number, Ro, and the dimensionless radial velocity component at the periphery of the cavity, U{sub o}. Results show that boundary layers merge for Re < < 10 and Ro > > 0.1, and boundary layers become predominantly non-entraining for low Ro, low Re, and high U{sub o}. Results may contribute to improve the design of technology, such as heat exchange devices, and turbomachinery.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29713288','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29713288"><span>3D Fluid-Structure Interaction Simulation of Aortic Valves Using a Unified Continuum ALE FEM Model.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Spühler, Jeannette H; Jansson, Johan; Jansson, Niclas; Hoffman, Johan</p> <p>2018-01-01</p> <p>Due to advances in medical imaging, computational fluid dynamics algorithms and high performance computing, computer simulation is developing into an important tool for understanding the relationship between cardiovascular diseases and intraventricular blood flow. The field of cardiac flow simulation is challenging and highly interdisciplinary. We apply a computational framework for automated solutions of partial differential equations using Finite Element Methods where any mathematical description directly can be translated to code. This allows us to develop a cardiac model where specific properties of the heart such as fluid-structure interaction of the aortic valve can be added in a modular way without extensive efforts. In previous work, we simulated the blood flow in the left ventricle of the heart. In this paper, we extend this model by placing prototypes of both a native and a mechanical aortic valve in the outflow region of the left ventricle. Numerical simulation of the blood flow in the vicinity of the valve offers the possibility to improve the treatment of aortic valve diseases as aortic stenosis (narrowing of the valve opening) or regurgitation (leaking) and to optimize the design of prosthetic heart valves in a controlled and specific way. The fluid-structure interaction and contact problem are formulated in a unified continuum model using the conservation laws for mass and momentum and a phase function. The discretization is based on an Arbitrary Lagrangian-Eulerian space-time finite element method with streamline diffusion stabilization, and it is implemented in the open source software Unicorn which shows near optimal scaling up to thousands of cores. Computational results are presented to demonstrate the capability of our framework.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5911501','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5911501"><span>3D Fluid-Structure Interaction Simulation of Aortic Valves Using a Unified Continuum ALE FEM Model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Spühler, Jeannette H.; Jansson, Johan; Jansson, Niclas; Hoffman, Johan</p> <p>2018-01-01</p> <p>Due to advances in medical imaging, computational fluid dynamics algorithms and high performance computing, computer simulation is developing into an important tool for understanding the relationship between cardiovascular diseases and intraventricular blood flow. The field of cardiac flow simulation is challenging and highly interdisciplinary. We apply a computational framework for automated solutions of partial differential equations using Finite Element Methods where any mathematical description directly can be translated to code. This allows us to develop a cardiac model where specific properties of the heart such as fluid-structure interaction of the aortic valve can be added in a modular way without extensive efforts. In previous work, we simulated the blood flow in the left ventricle of the heart. In this paper, we extend this model by placing prototypes of both a native and a mechanical aortic valve in the outflow region of the left ventricle. Numerical simulation of the blood flow in the vicinity of the valve offers the possibility to improve the treatment of aortic valve diseases as aortic stenosis (narrowing of the valve opening) or regurgitation (leaking) and to optimize the design of prosthetic heart valves in a controlled and specific way. The fluid-structure interaction and contact problem are formulated in a unified continuum model using the conservation laws for mass and momentum and a phase function. The discretization is based on an Arbitrary Lagrangian-Eulerian space-time finite element method with streamline diffusion stabilization, and it is implemented in the open source software Unicorn which shows near optimal scaling up to thousands of cores. Computational results are presented to demonstrate the capability of our framework. PMID:29713288</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AcAau.139...85S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AcAau.139...85S"><span>Numerical simulation on the powder propellant pickup characteristics of feeding system at high pressure</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Haijun; Hu, Chunbo; Zhu, Xiaofei</p> <p>2017-10-01</p> <p>A numerical study of powder propellant pickup progress at high pressure was presented in this paper by using two-fluid model with kinetic theory of granular flow in the computational fluid dynamics software package ANSYS/Fluent. Simulations were conducted to evaluate the effects of initial pressure, initial powder packing rate and mean particle diameter on the flow characteristics in terms of velocity vector distribution, granular temperature, pressure drop, particle velocity and volume. The numerical results of pressure drop were also compared with experiments to verify the TFM model. The simulated results show that the pressure drop value increases as the initial pressure increases, and the granular temperature under the conditions of different initial pressures and packing rates is almost the same in the area of throttling orifice plate. While there is an appropriate value for particle size and packing rate to form a ;core-annulus; structure in powder box, and the time-averaged velocity vector distribution of solid phase is inordinate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Litho.294..319L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Litho.294..319L"><span>Petrologic and stable isotopic studies of a fossil hydrothermal system in ultramafic environment (Chenaillet ophicalcites, Western Alps, France): Processes of carbonate cementation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lafay, Romain; Baumgartner, Lukas P.; Stephane, Schwartz; Suzanne, Picazo; German, Montes-Hernandez; Torsten, Vennemann</p> <p>2017-12-01</p> <p>The Late Jurassic Chenaillet ophiolitic complex (Western Alps) represents parts of an oceanic core-complex of the Liguria-Piemonte domain. A model for the origin and evolution of the Chenaillet ophicalcites based on textural and isotopic characterization is presented. The Chenaillet ophicalcites correspond to brecciated serpentinized peridotites that record seafloor shallow serpentinization at a minimum temperatures of 150 °C followed by authigenic carbonation. Carbonation starts with a network of micrometric to millimetric pre- or syn-clast formation calcite veins accompanied by a pervasive carbonation of residual olivine and serpentine inside the serpentinite mesh core. A matrix of small calcite (< 50 μm, 12 μm in average) cemented clasts after their individualization. Texture of the breccia, grain size distribution within the matrix, and chrysotile clusters support rapid cementation from a strongly oversaturated fluid due most likely to hydrothermal fluid cooling and decompression. Later fluids infiltrated by multiple crack formation and some dolomite locally formed along serpentinite-calcite interfaces. Carbonates have δ13C (VPDB) values that range between - 5‰ and + 0.4‰. The lower values were obtained for calcite within the serpentinite clasts. The δ18O (VSMOW) values have a range between + 11‰ and + 16‰ in carbonated clasts. The δ18O values in the matrix are fairly homogeneous with an average at + 12‰ and the late calcite veins have values between + 12.5 and + 15.5‰. These values suggest a relatively high temperature of formation for all the carbonates. Carbonates within clast are mainly characterized by a formation temperature in the range of 110 °C to 180 °C assuming a δ18O value of seawater of 0‰, the matrix forms at a temperature of ca. 165 °C. Late veins are characterized by a formation temperature ranging between 120and 155 °C. We propose a model where serpentinization is followed by discrete carbonation then brecciation and cementation as a consequence of continuous hydrothermal fluid circulation in the serpentinite basement. This is comparable to observations made in the stockwork of present-day long-lived oceanic hydrothermal systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035383','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035383"><span>Postimpact heat conduction and compaction-driven fluid flow in the Chesapeake Bay impact structure based on downhole vitrinite reflectance data, ICDP-USGS Eyreville deep core holes and Cape Charles test holes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Malinconico, M.L.; Sanford, W.E.; Wright, Horton W.J.J.</p> <p>2009-01-01</p> <p>Vitrinite reflectance data from the International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) Eyreville deep cores in the centralcrater moat of the Chesapeake Bay impact structure and the Cape Charles test holes on the central uplift show patterns of postimpact maximum-temperature distribution that result from a combination of conductive and advective heat flow. Within the crater-fill sediment-clast breccia sequence at Eyreville, an isoreflectance (-0.44% Ro) section (525-1096 m depth) is higher than modeled background coastal-plain maturity and shows a pattern typical of advective fluid flow. Below an intervening granite slab, a short interval of sediment-clast breccia (1371-1397 m) shows a sharp increase in reflectance (0.47%-0.91% Ro) caused by conductive heat from the underlying suevite (1397-1474 m). Refl ectance data in the uppermost suevite range from 1.2% to 2.1% Ro. However, heat conduction alone is not sufficient to affect the temperature of sediments more than 100 m above the suevite. Thermal modeling of the Eyreville suevite as a 390 ??C cooling sill-like hot rock layer supplemented by compaction- driven vertical fluid flow (0.046 m/a) of cooling suevitic fluids and deeper basement brines (120 ??C) upward through the sediment breccias closely reproduces the measured reflectance data. This scenario would also replace any marine water trapped in the crater fill with more saline brine, similar to that currently in the crater, and it would produce temperatures sufficient to kill microbes in sediment breccias within 450 m above the synimsuevite. A similar downhole maturity pattern is present in the sediment-clast breccia over the central uplift. High-reflectance (5%-9%) black shale and siltstone clasts in the suevite and sediment-clast breccia record a pre-impact (Paleozoic?) metamorphic event. Previously published maturity data in the annular trough indicate no thermal effect there from impact-related processes. ?? 2009 The Geological Society of America.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940013889','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940013889"><span>High-performance multiprocessor architecture for a 3-D lattice gas model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, F.; Flynn, M.; Morf, M.</p> <p>1991-01-01</p> <p>The lattice gas method has recently emerged as a promising discrete particle simulation method in areas such as fluid dynamics. We present a very high-performance scalable multiprocessor architecture, called ALGE, proposed for the simulation of a realistic 3-D lattice gas model, Henon's 24-bit FCHC isometric model. Each of these VLSI processors is as powerful as a CRAY-2 for this application. ALGE is scalable in the sense that it achieves linear speedup for both fixed and increasing problem sizes with more processors. The core computation of a lattice gas model consists of many repetitions of two alternating phases: particle collision and propagation. Functional decomposition by symmetry group and virtual move are the respective keys to efficient implementation of collision and propagation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PEPI..275...19A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PEPI..275...19A"><span>Observation of core sensitive phases: Constraints on the velocity and attenuation profile in the vicinity of the inner-core boundary</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adam, J. M.-C.; Ibourichène, A.; Romanowicz, B.</p> <p>2018-02-01</p> <p>We measured more than three thousand differential travel-times and amplitude ratios of PKPBC , PKPBC-diff , PKPAB and PKPDF phases in the epicentral distance range [149°-171°], from high quality records of globally distributed broadband stations. In particular, this is the largest collection of differential measurements of PKPBC-diff compared to PKPDF , extending by ∼ 10 ° the epicentral distance range in which the diffracted PKPBC phase has been observed globally. We used forward modelling of waveforms using the Direct Solution Method combined with a grid-search approach to explore attenuation and P-velocity structure in the vicinity of the inner core boundary (ICB) that can explain our observations. We find that, in order to simultaneously explain differential travel times and amplitude ratios of PKPBC , PKPBC-diff with respect to PKPDF out to distances of 165 ° , while fitting PKPAB /PKPDF within measurement errors, it is necessary to introduce a ∼ 450km zone of reduced bulk quality factor (Qκ ∼ 600) at the base of the outer core, while Qκ is close to 200 in a layer ∼ 150km thick at the top of the inner core. Concurrently, the P-velocity in the last 100 km of the outer-core is on average about 0.5 % slower than in the reference model AK 135 , while it is about 0.5 % faster in the top 150 km of the inner-core, resulting in a P-velocity jump at the inner core boundary slightly higher than in model AK 135 . However, this model underpredicts PKPBC-diff /PKPDF amplitude ratios at distances larger than 165 ° . Reducing Qκ even further in the last 100 km of the outer-core (down to Qκ = 50) provides a good fit to these data but it is not compatible with measurements of PKiKP/PKPDF amplitude ratios in the distance range 120-140°. We also considered a previously assembled global collection of "M phase" data. The M phase is a large energy in the coda of the PKPBC and PKPBC-diff that is not predicted by current 1 D reference seismic models, but most likely originates at the base of the outer-core. Our preferred model predicts the presence of an M phase, but significantly underestimates its amplitude. In order to explain the large amplitude of the M-phase and that of PKPBC-diff at distances larger than 165 ° without significantly affecting PKiKP amplitudes, it seems necessary to invoke a process that would produce strong scattering for diffracted phases in the immediate vicinity of the ICB, on the outer core side. Clusters of solid particles suspended in the fluid core or topography of the ICB are possible candidates that should be explored further.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25208960','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25208960"><span>Guiding principles of fluid and volume therapy.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aditianingsih, Dita; George, Yohanes W H</p> <p>2014-09-01</p> <p>Fluid therapy is a core concept in the management of perioperative and critically ill patients for maintenance of intravascular volume and organ perfusion. Recent evidence regarding the vascular barrier and its role in terms of vascular leakage has led to a new concept for fluid administration. The choice of fluid used should be based on the fluid composition and the underlying pathophysiology of the patient. Avoidance of both hypo- and hypervolaemia is essential when treating circulatory failure. In daily practice, the assessment of individual thresholds in order to optimize cardiac preload and avoid hypovolaemia or deleterious fluid overload remains a challenge. Liberal versus restrictive fluid management has been challenged by recent evidence, and the ideal approach appears to be goal-directed fluid therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT........57C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT........57C"><span>Fluid Enhanced Deformation and Metamorphism in Exhumed Lower Crust from the Northern Madison Range, Southwestern Montana, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Condit, Cailey Brown</p> <p></p> <p>Deep crustal processes during collisional orogenesis exert first-order controls on the development, scale and behavior of an orogenic belt. The presence or absence of fluids play important roles in these processes by enhancing deformation, catalyzing chemical reactions, and facilitating wholesale alteration of lithologic properties. However, the scales over which these fluid-related interactions occur and the specific feedbacks among them remain poorly constrained. The late Paleoproterozoic Big Sky orogen, expressed as high-grade deep crust exposed in the Laramide basement-cored uplifts of SW Montana, USA, offers an exceptional natural laboratory to address some of these questions. New data are presented from field and structural analysis, petrology, geochemistry, and geochronology in the Northern Madison Range, a key locality for constraining the hinterland-foreland transition of the orogen. Combined with other regional data, the age of high-grade metamorphism youngs by 80-40 Myr across an 100 km transect suggesting propagation of the orogenic core towards its foreland over time. In the southeastern part of the Northern Madison Range, two domains separated by a km-scale ductile shear zone, were transformed by hydrous fluids at significantly different spatial scales. The Gallatin Peak terrane was widely metamorphosed, metasomatized, and penetratively deformed in the presence of fluids at upper amphibolite facies during the Big Sky orogeny. Together, these data suggest that this area was pervasively hydrated and deformed over scales of several kilometers during thermotectonism at 30-25 km paleodepths. In the Moon Lake block, fluid flow at similar crustal depths and temperatures played a more localized but equally important role. Discrete flow along brittle fractures in metagabbronorite dikes led to nucleation of cm-scale ductile shear zones and metasomatic alteration. A model for shear zone evolution is presented that requires feedbacks between mechanical and chemical processes for strain localization. Seismic anisotropy was calculated for one of these shear zones. Deformation-induced crystallographic preferred orientation (CPO) of anisotropic minerals typically produces seismic anisotropy in the deep crust. However, this shear zone deformed by mechanisms that yielded no significant CPO, in part due to the fluid-rich environment, and very low seismic anisotropy, suggesting that high anisotropy does not always correlate with high strain.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H53B1411O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H53B1411O"><span>IMPACT OF PHYSICAL AND CHEMICAL MUD CONTAMINATION ON WELLBORE CEMENT- FORMATION SHEAR BOND STRENGTH Authors: Arome Oyibo1 and Mileva Radonjic1 * 1. Craft and Hawkins Department of Petroleum Engineering, 2131 Patrick F. Taylor Hall, Louisiana State University, Baton Rouge, LA 70803, aoyibo1@tigers.lsu.edu, mileva@lsu.edu</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oyibo, A. E.</p> <p>2013-12-01</p> <p>Wellbore cement has been used to provide well integrity through zonal isolation in oil & gas wells and geothermal wells. Cementing is also used to provide mechanical support for the casing and protect the casing from corrosive fluids. Failure of cement could be caused by several factors ranging from poor cementing, failure to completely displace the drilling fluids to failure on the path of the casing. A failed cement job could result in creation of cracks and micro annulus through which produced fluids could migrate to the surface which could lead to sustained casing pressure, contamination of fresh water aquifer and blow out in some cases. In addition, cement failures could risk the release of chemicals substances from hydraulic fracturing into fresh water aquifer during the injection process. To achieve proper cementing, the drilling fluid should be completely displaced by the cement slurry. However, this is hard to achieve in practice, some mud is usually left on the wellbore which ends up contaminating the cement afterwards. The purpose of this experimental study is to investigate the impact of both physical and chemical mud contaminations on cement-formation bond strength for different types of formations. Physical contamination occurs when drilling fluids (mud) dries on the surface of the formation forming a mud cake. Chemical contamination on the other hand occurs when the drilling fluids which is still in the liquid form interacts chemically with the cement during a cementing job. We investigated the impact of the contamination on the shear bond strength and the changes in the mineralogy of the cement at the cement-formation interface to ascertain the impact of the contamination on the cement-formation bond strength. Berea sandstone and clay rich shale cores were bonded with cement cores with the cement-formation contaminated either physically or chemically. For the physically contaminated composite cores, we have 3 different sample designs: clean/not contaminated, scrapped and washed composite cores. Similarly, for the chemically contaminated samples we had 3 different sample designs: 0%, 5% and 10% mud contaminated composite cores. Shear test were performed on the composite cores to determine the shear bond strength and the results suggested that the detrimental impact of the contamination is higher when the cores are physically contaminated i.e. when we have mud cake present at the surface of the wellbore before a cement job is performed. Also, the results showed that shear bond strength is higher for sandstone formations as compared to shale formations. Material characterization analysis was carried out to determine the micro structural changes at the cement-formation interface. The results obtained from the SEM and micro CT images taken at the bond interface confirmed that chemical contamination caused substantial changes in the spatial distribution of minerals that impacted bond strength. Keywords: Cement-Formation bond strength, mud contamination, shale, sandstone and material characterization *Corresponding author</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19730961','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19730961"><span>Use of standard hypodermic needles for accessing laparoscopic adjustable gastric band ports.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bewsher, Samuel Mark; Azzi, Anthony; Wright, Timothy</p> <p>2010-06-01</p> <p>Laparoscopic adjustable gastric banding is a common and successful method of surgically treating morbid obesity. A recipient will have to attend their surgeon's rooms a number of times to optimally adjust the amount of fluid in the band and hence the amount of restriction. Manufacturers suggest that the ports should be accessed with special non-coring needles that may not always be available in regional or remote centers, and this could create a safety risk in cases where urgent band deflation is required. Ports of two different brands were repeatedly accessed over 100 times in the same location while containing fluid under pressure, using a standard beveled 21 g hypodermic needle (SN) and a 20 g Huber tipped non-coring needle (NCN). The path the needles types took through the port septum was also examined. There was no leakage of fluid from any of the ports tested. Neither SN nor NCN passed through the port septum down their axis, but rather in a direction closer to that of their beveled surface. There is no more risk of "coring" the septum with a SN than with a NCN. SN can be used safely and routinely to access laparoscopic adjustable gastric band ports.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930083614','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930083614"><span>Study of secondary-flow patterns in an annular cascade of turbine nozzle blades with vortex design</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rohlik, Harold E; Allen, Hubert W; Herzig, Howard Z</p> <p>1953-01-01</p> <p>In order to increase understanding of the origin of losses in a turbine, the secondary-flow components in the boundary layers and the blade wakes of an annular cascade of turbine nozzle blades (vortex design) was investigated. A detailed study was made of the total-pressure contours and, particularly, of the inner-wall loss cores downstream of the blades. The inner-wall loss core associated with a blade of the turbine-nozzle cascade is largely the accumulation of low-momentum fluids originating elsewhere in the cascade. This accumulation is effected by a secondary-flow mechanism which acts to transport the low-momentum fluids across the channels on the walls and radially in the blade wakes and boundary layers. The patterns of secondary flow were determined by use of hydrogen sulfide traces, paint, flow fences, and total pressure surveys. At one flow condition investigated, the radial transport of low-momentum fluid in the blade wake and on the suction surface near the trailing edge accounted for 65 percent of the loss core; 30 percent resulted from flow in the thickened boundary layer on the suction surface and 35 percent from flow in the blade wake.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A11E1933T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A11E1933T"><span>Next Generation Community Based Unified Global Modeling System Development and Operational Implementation Strategies at NCEP</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tallapragada, V.</p> <p>2017-12-01</p> <p>NOAA's Next Generation Global Prediction System (NGGPS) has provided the unique opportunity to develop and implement a non-hydrostatic global model based on Geophysical Fluid Dynamics Laboratory (GFDL) Finite Volume Cubed Sphere (FV3) Dynamic Core at National Centers for Environmental Prediction (NCEP), making a leap-step advancement in seamless prediction capabilities across all spatial and temporal scales. Model development efforts are centralized with unified model development in the NOAA Environmental Modeling System (NEMS) infrastructure based on Earth System Modeling Framework (ESMF). A more sophisticated coupling among various earth system components is being enabled within NEMS following National Unified Operational Prediction Capability (NUOPC) standards. The eventual goal of unifying global and regional models will enable operational global models operating at convective resolving scales. Apart from the advanced non-hydrostatic dynamic core and coupling to various earth system components, advanced physics and data assimilation techniques are essential for improved forecast skill. NGGPS is spearheading ambitious physics and data assimilation strategies, concentrating on creation of a Common Community Physics Package (CCPP) and Joint Effort for Data Assimilation Integration (JEDI). Both initiatives are expected to be community developed, with emphasis on research transitioning to operations (R2O). The unified modeling system is being built to support the needs of both operations and research. Different layers of community partners are also established with specific roles/responsibilities for researchers, core development partners, trusted super-users, and operations. Stakeholders are engaged at all stages to help drive the direction of development, resources allocations and prioritization. This talk presents the current and future plans of unified model development at NCEP for weather, sub-seasonal, and seasonal climate prediction applications with special emphasis on implementation of NCEP FV3 Global Forecast System (GFS) and Global Ensemble Forecast System (GEFS) into operations by 2019.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.7351M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.7351M"><span>Internal structure of the Moon inferred from Apollo seismic data and selenodetic data from GRAIL and LLR</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsumoto, Koji; Yamada, Ryuhei; Kikuchi, Fuyuhiko; Kamata, Shunichi; Ishihara, Yoshiaki; Iwata, Takahiro; Hanada, Hideo; Sasaki, Sho</p> <p>2015-09-01</p> <p>The internal structure of the Moon is important for discussions on its origin and evolution. However, the deep structure of the Moon is still debated due to the absence of comprehensive seismic data. This study explores lunar interior models by complementing Apollo seismic travel time data with selenodetic data which have recently been improved by Gravity Recovery and Interior Laboratory (GRAIL) and Lunar Laser Ranging (LLR). The observed data can be explained by models including a deep-seated zone with a low velocity (S wave velocity = 2.9 ± 0.5 km/s) and a low viscosity (˜3 × 1016 Pa s). The thickness of this zone above the core-mantle boundary is larger than 170 km, showing a negative correlation with the radius of the fluid outer core. The inferred density of the lowermost mantle suggests a high TiO2 content (>11 wt.%) which prefers a mantle overturn scenario.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1064052','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1064052"><span>PARTICLE IMAGE VELOCIMETRY MEASUREMENTS IN A REPRESENTATIVE GAS-COOLED PRISMATIC REACTOR CORE MODEL: FLOW IN THE COOLANT CHANNELS AND INTERSTITIAL BYPASS GAPS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Thomas E. Conder; Richard Skifton; Ralph Budwig</p> <p></p> <p>Core bypass flow is one of the key issues with the prismatic Gas Turbine-Modular Helium Reactor, and it refers to the coolant that navigates through the interstitial, non-cooling passages between the graphite fuel blocks instead of traveling through the designated coolant channels. To determine the bypass flow, a double scale representative model was manufactured and installed in the Matched Index-of-Refraction flow facility; after which, stereo Particle Image Velocimetry (PIV) was employed to measure the flow field within. PIV images were analyzed to produce vector maps, and flow rates were calculated by numerically integrating over the velocity field. It was foundmore » that the bypass flow varied between 6.9-15.8% for channel Reynolds numbers of 1,746 and 4,618. The results were compared to computational fluid dynamic (CFD) pre-test simulations. When compared to these pretest calculations, the CFD analysis appeared to under predict the flow through the gap.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S43B0855C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S43B0855C"><span>Experimental Evidence of Volcanic Earthquakes Induced by Different Fluid Types</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clarke, J. A.; Adam, L.; Sarout, J.; van Wijk, K.; Dautriat, J. D.; Kennedy, B.</p> <p>2017-12-01</p> <p>Low Frequency volcanic seismicity has long been associated with resonance in fluid-filled cracks or conduits driven by pressure perturbations at depth. In volcano monitoring, fluid movement, fracturing and the conduit geometry are interpreted based on field observations, laboratory experiments, and numerical models. Fluids in a volcanic environment include gasses, brine and magmas with different viscosities. Magma viscosity is a key influence on eruptive behaviour. For example, increasing magma viscosity is known to favour explosive eruptions. How different fluids affect volcano seismicity is not well understood. Here, we explore the effects of fluid type on volcano seismic signals. Frequency content in the signal, frequency of the events, source mechanism and quality factor are studied. We simulate volcano tectonic (fracturing) and volcano seismic (fluid movement) signatures in a controlled laboratory environment using a range of rock samples, fluid types and pressure conditions. The viscosity of the fluids spans six orders of magnitude, representing realistic volcanic fluids. Microseismicity is generated by venting pressurised fluids through pre-generated fracture networks in cylindrical rock core samples and detected by an array of 18 ultrasonic transducers. We fracture samples of two lithologies: 1) low porosity impermeable granite samples and 2) a permeable volcanic ash tuff sample. Permeability and porosity in the granites are due to a fracture network, while in the tuff a high porosity matrix ( 40 %) and a fracture network interact. The fluids used are nitrogen gas, water, and mixtures of water and glycerol. We generate and detect a myriad of seismic event types, some of which resemble well-known families of volcano-tectonic, low-frequency, hybrid and tremor-type seismicity. Samples with fluids of lower density and viscosity generate a higher number of seismic events. We will present an integrated analysis of the event types, frequency content, source locations and mechanisms. In addition, we explore the importance of seismic wave attenuation by studying the relationship between wave path and event frequency content.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28893692','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28893692"><span>Formation of mannitol core microparticles for sustained release with lipid coating in a mini fluid bed system.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Bifeng; Friess, Wolfgang</p> <p>2017-11-01</p> <p>The goal of this study was to prepare sustained release microparticles for methyl blue and aspartame as sparingly and freely water-soluble model drugs by lipid film coating in a Mini-Glatt fluid bed, and to assess the effect of coating load of two of lipids, hard fat and glyceryl stearate, on the release rates. 30g drug-loaded mannitol carrier microparticles with average diameter of 500 or 300μm were coated with 5g, 10g, 20g and 30g lipids, respectively. The model drugs were completely released in vitro through pores which mainly resulted from dissolution of the polyol core beads. The release of methyl blue from microparticles based on 500μm carrier beads extended up to 25days, while aspartame release from microparticles formed from 300μm carrier beads was extended to 7days. Although glyceryl stearate exhibits higher wettability, burst and release rates were similar for the two lipid materials. Polymorphic transformation of the hart fat was observed upon release. The lipid-coated microparticles produced with 500μm carrier beads showed slightly lower burst release compared to the microparticles produced with 300μm carrier beads as they carried relatively thicker lipid layer based on an equivalent lipid to mannitol ratio. Aspartame microparticles showed a much faster release than methyl blue due to the higher water-solubility of aspartame. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyA..457..492P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyA..457..492P"><span>Characterization of the structural collapse undergone by an unstable system of ultrasoft particles</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prestipino, Santi; Malescio, Gianpietro</p> <p>2016-09-01</p> <p>The effective repulsion between macromolecules such as polymer chains or dendrimers is everywhere finite, implying that interaction centers can even coincide. If, in addition, the large-distance attraction is sufficiently strong, then the system is driven unstable. An unstable system lacks a conventional thermodynamics since, in the infinite-size limit, it eventually collapses to a finite-size cluster (for instance, a polymer dispersion undergoes irreversible coagulation when increasing the amount of dissolved salt beyond a certain limit). Using a double-Gaussian (DG) potential for demonstration, we study the phase behavior of a system of ultrasoft particles as a function of the attraction strength η. Above a critical threshold ηc, the DG system is unstable but its collective behavior is far from trivial since two separate regions of the thermodynamic plane can be identified, based on the value taken by the average waiting time for collapse: this is finite and small on one side of the boundary, while presumably infinite in the other region. In order to make sense of this evidence, we consider a stable system of particles interacting through a DG potential augmented with a hard core (stabilized DG, or SDG potential). We provide arguments supporting the view that the boundary line of the unstable DG model is the remnant of the spinodal line of a fluid-fluid phase transition occurring in the SDG model when the hard-core diameter is sent to zero.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V41A2749C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V41A2749C"><span>Sulfur Isotope Analysis of Minerals and Fluids in a Natural CO2 Reservoir, Green River, Utah</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, F.; Kampman, N.; Bickle, M. J.; Busch, A.; Turchyn, A. V.</p> <p>2013-12-01</p> <p>Predicting the security of geological CO2 storage sites requires an understanding of the geochemical behavior of the stored CO2, especially of fluid-rock reactions in reservoirs, caprocks and fault zones. Factors that may influence geochemical behavior include co-injection of sulfur gases along with the CO2, either in acid-gas disposal or as contaminants in CO2 storage sites, and microbial activity, such as bacterial sulfate reduction. The latter may play an important role in buffering the redox chemistry of subsurface fluids, which could affect toxic trace metal mobilization and transport in acidic CO2-rich fluids. These processes involving sulfur are poorly understood. Natural CO2-reservoirs provide natural laboratories, where the flow and reactions of the CO2-charged fluids and the activity of microbial communities are integrated over sufficient time-scales to aid prediction of long-term CO2 storage. This study reports on sulfur isotope analyses of sulfate and sulfide minerals in rock core and in CO2-charged fluids collected from a stacked sequence of natural CO2 reservoirs at Green River, Utah. Scientific drilling adjacent to a CO2-degassing normal fault to a depth of 325m retrieved core and fluid samples from two CO2 reservoirs in the Entrada and Navajo Sandstones and from the intervening Carmel Formation caprock. Fluid samples were collected from CO2-charged springs that discharge through the faults. Sulfur exists as sulfate in the fluids, as sedimentary gypsum beds in the Carmel Formation, as remobilized gypsum veins within a fault damage zone in the Carmel Fm. and in the Entrada Sandstone, and as disseminated pyrite and pyrite-mineralized open fractures throughout the cored interval. We use the stable sulfur (δ34S) and oxygen (δ18OSO4) isotopes of the sulfate, gypsum, and pyrite to understand the source of sulfur in the reservoir as well as the timing of gypsum vein and pyrite formation. The hydration water of the gypsum is also reported to explore the different timing of gypsum vein formation. Macroscopic and microscopic gradients in the sulfur isotope composition of pyrite throughout the core and at discernible redox-reaction fronts were examined in detail to assess the role of bacteria in mediating sulfate reduction, sulfide mineralization and buffering of groundwater redox chemistry. The CO2 charged fluids and gypsum veins within the Entrada Sandstone have a narrow and very similar range in both δ34SSO4 and δ18OSO4, suggesting that the fluids (9.1-10.7‰) are the most likely source of the sulfate in the veins (11.4-12.8‰) and that the veins formed during recent fluid flow through the Entrada, with sulfate coming from remobilized gypsum beds in the Carmel. The Carmel also contains two isotopically distinct types of gypsum veins: one with δ34SSO4 values similar to the Entrada veins and one with much higher δ34SSO4 values (15.1-16.1‰). The latter are likely primary gypsum, while the former are likely secondary gypsum. Sulfur isotope fractionation between pyrite (-16.5‰ to -35.7‰) at the Carmel-Navajo interface and reservoir fluids (9.1-10.7‰) suggest that sulfur reducing bacteria play a role in producing the deposited sulfide. This data demonstrates active sulfur cycling in CO2 reservoirs with many different sulfur species cycled among various pools creating the wide isotope dispersion we observe.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1399093','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1399093"><span>Passive filtration of air egressing from nuclear containment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Malloy, III, John D</p> <p>2017-09-26</p> <p>A nuclear reactor includes a reactor core comprising fissile material disposed in a reactor pressure vessel. A radiological containment contains the nuclear reactor. A containment compartment contains the radiological containment. A heat sink includes a chimney configured to develop an upward-flowing draft in response to heated fluid flowing into a lower portion of the chimney. A fluid conduit is arranged to receive fluid from the containment compartment and to discharge into the chimney. A filter may be provided, with the fluid conduit including a first fluid conduit arranged to receive fluid from the containment compartment and to discharge into anmore » inlet of the filter, and a second fluid conduit arranged to receive fluid from an outlet of the filter and to discharge into the chimney. As the draft is developed passively, there is no need for a blower or pump configured to move fluid through the fluid conduit.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5923514','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5923514"><span>Electrospun Blank Nanocoating for Improved Sustained Release Profiles from Medicated Gliadin Nanofibers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Xinkuan; Shao, Wenyi; Luo, Mingyi; Bian, Jiayin</p> <p>2018-01-01</p> <p>Nanomaterials providing sustained release profiles are highly desired for efficacious drug delivery. Advanced nanotechnologies are useful tools for creating elaborate nanostructure-based nanomaterials to achieve the designed functional performances. In this research, a modified coaxial electrospinning was explored to fabricate a novel core-sheath nanostructure (nanofibers F2), in which a sheath drug-free gliadin layer was successfully coated on the core ketoprofen (KET)-gliadin nanocomposite. A monolithic nanocomposite (nanofibers F1) that was generated through traditional blending electrospinning of core fluid was utilized as a control. Scanning electron microscopy demonstrated that both nanofibers F1 and F2 were linear. Transmission electron microscopy verified that nanofibers F2 featured a clear core-sheath nanostructure with a thin sheath layer about 25 nm, whereas their cores and nanofibers F1 were homogeneous KET-gliadin nanocomposites. X-ray diffraction patterns verified that, as a result of fine compatibility, KET was dispersed in gliadin in an amorphous state. In vitro dissolution tests demonstrated that the thin blank nanocoating in nanofibers F2 significantly modified drug release kinetics from a traditional exponential equation of nanofibers F1 to a zero-order controlled release model, linearly freeing 95.7 ± 4.7% of the loaded cargoes over a time period of 16 h. PMID:29565280</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29565280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29565280"><span>Electrospun Blank Nanocoating for Improved Sustained Release Profiles from Medicated Gliadin Nanofibers.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Xinkuan; Shao, Wenyi; Luo, Mingyi; Bian, Jiayin; Yu, Deng-Guang</p> <p>2018-03-22</p> <p>Nanomaterials providing sustained release profiles are highly desired for efficacious drug delivery. Advanced nanotechnologies are useful tools for creating elaborate nanostructure-based nanomaterials to achieve the designed functional performances. In this research, a modified coaxial electrospinning was explored to fabricate a novel core-sheath nanostructure (nanofibers F2), in which a sheath drug-free gliadin layer was successfully coated on the core ketoprofen (KET)-gliadin nanocomposite. A monolithic nanocomposite (nanofibers F1) that was generated through traditional blending electrospinning of core fluid was utilized as a control. Scanning electron microscopy demonstrated that both nanofibers F1 and F2 were linear. Transmission electron microscopy verified that nanofibers F2 featured a clear core-sheath nanostructure with a thin sheath layer about 25 nm, whereas their cores and nanofibers F1 were homogeneous KET-gliadin nanocomposites. X-ray diffraction patterns verified that, as a result of fine compatibility, KET was dispersed in gliadin in an amorphous state. In vitro dissolution tests demonstrated that the thin blank nanocoating in nanofibers F2 significantly modified drug release kinetics from a traditional exponential equation of nanofibers F1 to a zero-order controlled release model, linearly freeing 95.7 ± 4.7% of the loaded cargoes over a time period of 16 h.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.207..934H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.207..934H"><span>Magnetic to magnetic and kinetic to magnetic energy transfers at the top of the Earth's core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huguet, Ludovic; Amit, Hagay; Alboussière, Thierry</p> <p>2016-11-01</p> <p>We develop the theory for the magnetic to magnetic and kinetic to magnetic energy transfer between different spherical harmonic degrees due to the interaction of fluid flow and radial magnetic field at the top of the Earth's core. We show that non-zero secular variation of the total magnetic energy could be significant and may provide evidence for the existence of stretching secular variation, which suggests the existence of radial motions at the top of the Earth's core-whole core convection or MAC waves. However, the uncertainties of the small scales of the geomagnetic field prevent a definite conclusion. Combining core field and flow models we calculate the detailed magnetic to magnetic and kinetic to magnetic energy transfer matrices. The magnetic to magnetic energy transfer shows a complex behaviour with local and non-local transfers. The spectra of magnetic to magnetic energy transfers show clear maxima and minima, suggesting an energy cascade. The kinetic to magnetic energy transfers, which are much weaker due to the weak poloidal flow, are either local or non-local between degree one and higher degrees. The patterns observed in the matrices resemble energy transfer patterns that are typically found in 3-D MHD numerical simulations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006APS..DFD.GD007D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006APS..DFD.GD007D"><span>Instability patterns in a miscible core annular flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Olce, Marguerite; Martin, Jerome; Rakotomalala, Nicole; Salin, Dominique; Talon, Laurent</p> <p>2006-11-01</p> <p>Laboratoire FAST, batiment 502, campus universitaire, 91405 Orsay Cedex (France). Experiments are performed with two miscible fluids of equal density but different viscosities. The fluids are injected co-currently and concentrically into a cylindrical pipe. The so-obtained base state is an axisymmetric parallel flow, for which the ratio of the flow rates of the two fluids monitors the relative amount (and so the radius) of the fluids. Depending on this relative amount and on the total flow rate of the fluids, unstable axisymmetric patterns such as mushrooms and pearls are observed. We delineate the diagram of occurrence of the two patterns and characterize the instabilities.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/876245','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/876245"><span>Characterization of Fuego for laminar and turbulent natural convection heat transfer.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Francis, Nicholas Donald, Jr.; .)</p> <p>2005-08-01</p> <p>A computational fluid dynamics (CFD) analysis is conducted for internal natural convection heat transfer using the low Mach number code Fuego. The flow conditions under investigation are primarily laminar, transitional, or low-intensity level turbulent flows. In the case of turbulent boundary layers at low-level turbulence or transitional Reynolds numbers, the use of standard wall functions no longer applies, in general, for wall-bounded flows. One must integrate all the way to the wall in order to account for gradients in the dependent variables in the viscous sublayer. Fuego provides two turbulence models in which resolution of the near-wall region is appropriate.more » These models are the v2-f turbulence model and a Launder-Sharma, low-Reynolds number turbulence model. Two standard geometries are considered: the annulus formed between horizontal concentric cylinders and a square enclosure. Each geometry emphasizes wall shear flow and complexities associated with turbulent or near turbulent boundary layers in contact with a motionless core fluid. Overall, the Fuego simulations for both laminar and turbulent flows compared well to measured data, for both geometries under investigation, and to a widely accepted commercial CFD code (FLUENT).« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1129934','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1129934"><span>Comparison of the PHISICS/RELAP5-3D Ring and Block Model Results for Phase I of the OECD MHTGR-350 Benchmark</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gerhard Strydom</p> <p>2014-04-01</p> <p>The INL PHISICS code system consists of three modules providing improved core simulation capability: INSTANT (performing 3D nodal transport core calculations), MRTAU (depletion and decay heat generation) and a perturbation/mixer module. Coupling of the PHISICS code suite to the thermal hydraulics system code RELAP5-3D has recently been finalized, and as part of the code verification and validation program the exercises defined for Phase I of the OECD/NEA MHTGR 350 MW Benchmark were completed. This paper provides an overview of the MHTGR Benchmark, and presents selected results of the three steady state exercises 1-3 defined for Phase I. For Exercise 1,more » a stand-alone steady-state neutronics solution for an End of Equilibrium Cycle Modular High Temperature Reactor (MHTGR) was calculated with INSTANT, using the provided geometry, material descriptions, and detailed cross-section libraries. Exercise 2 required the modeling of a stand-alone thermal fluids solution. The RELAP5-3D results of four sub-cases are discussed, consisting of various combinations of coolant bypass flows and material thermophysical properties. Exercise 3 combined the first two exercises in a coupled neutronics and thermal fluids solution, and the coupled code suite PHISICS/RELAP5-3D was used to calculate the results of two sub-cases. The main focus of the paper is a comparison of the traditional RELAP5-3D “ring” model approach vs. a much more detailed model that include kinetics feedback on individual block level and thermal feedbacks on a triangular sub-mesh. The higher fidelity of the block model is illustrated with comparison results on the temperature, power density and flux distributions, and the typical under-predictions produced by the ring model approach are highlighted.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25177717','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25177717"><span>Estimation of the iron loss in deep-sea permanent magnet motors considering seawater compressive stress.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Yongxiang; Wei, Yanyu; Zou, Jibin; Li, Jianjun; Qi, Wenjuan; Li, Yong</p> <p>2014-01-01</p> <p>Deep-sea permanent magnet motor equipped with fluid compensated pressure-tolerant system is compressed by the high pressure fluid both outside and inside. The induced stress distribution in stator core is significantly different from that in land type motor. Its effect on the magnetic properties of stator core is important for deep-sea motor designers but seldom reported. In this paper, the stress distribution in stator core, regarding the seawater compressive stress, is calculated by 2D finite element method (FEM). The effect of compressive stress on magnetic properties of electrical steel sheet, that is, permeability, BH curves, and BW curves, is also measured. Then, based on the measured magnetic properties and calculated stress distribution, the stator iron loss is estimated by stress-electromagnetics-coupling FEM. At last the estimation is verified by experiment. Both the calculated and measured results show that stator iron loss increases obviously with the seawater compressive stress.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.G33A..08W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.G33A..08W"><span>Lunar Rotation, Orientation and Science</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, J. G.; Ratcliff, J. T.; Boggs, D. H.</p> <p>2004-12-01</p> <p>The Moon is the most familiar example of the many satellites that exhibit synchronous rotation. For the Moon there is Lunar Laser Ranging measurements of tides and three-dimensional rotation variations plus supporting theoretical understanding of both effects. Compared to uniform rotation and precession the lunar rotational variations are up to 1 km, while tidal variations are about 0.1 m. Analysis of the lunar variations in pole direction and rotation about the pole gives moment of inertia differences, third-degree gravity harmonics, tidal Love number k2, tidal dissipation Q vs. frequency, dissipation at the fluid-core/solid-mantle boundary, and emerging evidence for an oblate boundary. The last two indicate a fluid core, but a solid inner core is not ruled out. Four retroreflectors provide very accurate positions on the Moon. The experience with the Moon is a starting point for exploring the tides, rotation and orientation of the other synchronous bodies of the solar system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss022e026221.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss022e026221.html"><span>Noguchi in the JPM during Expedition 22</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2010-01-15</p> <p>ISS022-E-026221 (15 Jan. 2010) --- Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, Expedition 22 flight engineer, services the Fluid Physics Experiment Facility/Marangoni Surface (FPEF MS) Core hardware in the Kibo laboratory of the International Space Station. The Marangoni convection experiment in the FPEF examines fluid tension flow in micro-G.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss022e025474.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss022e025474.html"><span>Noguchi in the JPM during Expedition 22</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2010-01-14</p> <p>ISS022-E-025474 (14 Jan. 2010) --- Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, Expedition 22 flight engineer, services the Fluid Physics Experiment Facility/Marangoni Surface (FPEF MS) Core hardware in the Kibo laboratory of the International Space Station. The Marangoni convection experiment in the FPEF examines fluid tension flow in micro-G.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DFD.A1002S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFD.A1002S"><span>Impact of drag reducing polymers on the onset of instability in a pipe with reverse flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shashank, H. J.; Sreenivas, K. R.</p> <p>2014-11-01</p> <p>The objective of this study is to understand the mechanism by which drag reducing polymer (DRP) additives modify turbulent flow, so as to reduce turbulent drag. Reverse flow in a pipe occurs when the fluid close to the wall moves in an opposite direction to that of the core fluid. Reverse flow is established by using a piston-cylinder mechanism, the programmed motion of which imparts a known impulse to the fluid. When the piston is stopped at the end of the stroke, fluid inertia makes the core of the flow to continue in the same direction. In order to conserve mass, reverse flow is established close to the wall. An inflection point is thus formed, leading to flow instability above a critical Reynolds number. Dye and streak flow visualization experiments are performed to highlight the impact of DRP additives (polyethylene oxide, PEO, dissolved in water). The time of onset of the instability and the wavelength of the observed instability are studied in systems with and without DRP additives. This study will provide further insight into the phenomenon of turbulent polymer drag reduction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22410083-characteristics-temperature-rise-variable-inductor-employing-magnetorheological-fluid-driven-high-frequency-pulsed-voltage-source','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22410083-characteristics-temperature-rise-variable-inductor-employing-magnetorheological-fluid-driven-high-frequency-pulsed-voltage-source"><span>Characteristics of temperature rise in variable inductor employing magnetorheological fluid driven by a high-frequency pulsed voltage source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lee, Ho-Young; Kang, In Man, E-mail: imkang@ee.knu.ac.kr; Shon, Chae-Hwa</p> <p>2015-05-07</p> <p>A variable inductor with magnetorheological (MR) fluid has been successfully applied to power electronics applications; however, its thermal characteristics have not been investigated. To evaluate the performance of the variable inductor with respect to temperature, we measured the characteristics of temperature rise and developed a numerical analysis technique. The characteristics of temperature rise were determined experimentally and verified numerically by adopting a multiphysics analysis technique. In order to accurately estimate the temperature distribution in a variable inductor with an MR fluid-gap, the thermal solver should import the heat source from the electromagnetic solver to solve the eddy current problem. Tomore » improve accuracy, the B–H curves of the MR fluid under operating temperature were obtained using the magnetic property measurement system. In addition, the Steinmetz equation was applied to evaluate the core loss in a ferrite core. The predicted temperature rise for a variable inductor showed good agreement with the experimental data and the developed numerical technique can be employed to design a variable inductor with a high-frequency pulsed voltage source.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B32C..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B32C..06D"><span>Geochemistry of pore-fluids related to the distribution of the biological communities on the giant Regab pockmark, off Gabon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Prunelé, A.; Caprais, J.; Ruffine, L.; Cassarino, L.; Guyader, V.; Bollinger, C.; Ondréas, H.; Donval, J.; Olu, K.; Geli, L. B.; Cunningham, K. L.; Cauquil, E.</p> <p>2013-12-01</p> <p>The Regab pockmark is a giant structure located at 3200 m water depth offshore Gabon and ~ 10 km north to the deep Congo channel (Zaïre canyon) (Gay et al. 2006; Ondréas et al. 2005). It has been visited for the first time in 2000 during the Zairov cruise. Since that time, several scientific cruises have allowed further investigations of this pockmark. The last cruise, WACS, for West Africa Cold Seeps, in January- February 2010, was undertaken on board the R/V ';Pourquoi Pas?' with the aim of identifying changes which can occur over time on this pockmark. Besides intensive ROV dives, three calypso cores and several push cores have been collected to better understand the relationships between the distribution of the living communities and the pore-fluids chemistry. In two calypso cores one collected within the pockmark and one outside, and both in areas without visible biological communities, pore-fluids profiles of dissolved elements (Alk, SO42-, Mn2+, Fe2+) show that degradation of organic matter is occurring and likely plays an important role in the sulfate reduction (Froelich et al. 1979). Methane was not detected. The Analysis of the pore-fluids by Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS) has shown the presence of alcohols, acid and phenol. These molecules are likely related to the degradation of organic matter and/or the production of the biological communities. Further investigations are ongoing to provide us with a clearer picture regarding the source of these molecules. The third calypso core collected in the northeast part of the pockmark containing gas hydrates. Sulfate profiles from the push cores show significant difference from one community to another. The analyses of both major and minor dissolved elements, along with molecular and isotopic methane concentration measurements are in progress for the push cores. The latter was done using a new analyzer G2201-i from Picarro for which new methods applied to pore-fluids has been developed. The resulting dataset will be discussed in the view of drawing relationships between the pore fluid chemistry and the distribution of the living communities. REFERENCE Gay A., Lopez M., Ondreas H., Charlou J-L., Sermondadaz G., Cochonat P. (2006) Seafloor facies related to upward methane flux within a Giant Pockmark of the Lower Congo Basin. Marine Geology, 226, 81-95. Ondréas H., Olu K., Fouquet Y., Charlou J., Gay A., Dennielou B., Donval J., Fifis A., Nadalig T., Cochonat P., Cauquil E., Bourillet J., Moigne M., and Sibuet M. (2005) ROV study of a giant pockmark on the Gabon continental margin. Geo-Marine Letters 25 : 281-292 Froelich, P.N., Klinkhammer, G.P., Bender, M.L., Luedtke, N.A., Heath, G.R., Cullen, D., Dauphin, P., Hammond, D., Hartman, B., and Maynard, V., 1979. Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic: Suboxic diagenesis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.2050E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2050E"><span>Simulating rotating fluid bodies: When is vorticity generation via density-stratification important?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evonuk, M.; Samuel, H.</p> <p>2012-04-01</p> <p>Differential rotation is one of the key components needed to maintain a magnetic dynamo, therefore it is important to understand the processes that generate differential rotation in rotating bodies. In a rotating density-stratified fluid, local vorticity generation occurs as fluid parcels move radially, expanding or contracting with respect to the background density stratification. The convergence of this vorticity forms zonal flow structures as a function of the radius and the slope of the background density profile. While this effect is thought to be of importance in bodies that are quickly rotating and highly turbulent with large density stratifications such as Jupiter, it is generally neglected in bodies such as the Earth's outer core, where the density change is small. Simulations of thermal convection in the 2D rotating equatorial plane are conducted to determine the parameter regime where local vorticity generation plays a significant role in organizing the fluid flow. Three regimes are found: a dipolar flow regime, where the flow is not organized by the rotation, a transitional flow regime, and a differential flow regime, where the flow is strongly organized into differential rotation with multiple jets. A scaling law is determined based on the convective Rossby number and the density contrast across the equatorial plane, providing a simple way to determine in which regime a given body lies. While a giant planet such as Jupiter lies firmly in the differential flow regime as expected, the Earth's outer core is also found to lie in the differential flow regime indicating that, even in the Earth's outer core, where the density contrast is small, vorticity contributions via fluid movement through the density stratification may be non-negligible.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGP21A1153E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGP21A1153E"><span>Simulating rotating fluid bodies: When is vorticity generation via density-stratification important?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evonuk, M.; Samuel, H.</p> <p>2012-12-01</p> <p>Differential rotation is one of the key components needed to maintain a magnetic dynamo, therefore it is important to understand the processes that generate differential rotation in rotating bodies. In a rotating density-stratified fluid, local vorticity generation occurs as fluid parcels move radially, expanding or contracting with respect to the background density stratification. The convergence of this vorticity forms zonal flow structures as a function of the radius and the slope of the background density profile. While this effect is thought to be of importance in bodies that are quickly rotating and highly turbulent with large density stratifications such as Jupiter, it is generally neglected in bodies such as the Earth's outer core, where the density change is small. Simulations of thermal convection in the 2D rotating equatorial plane are conducted to determine the parameter regime where local vorticity generation plays a significant role in organizing the fluid flow. Three regimes are found: a dipolar flow regime, where the flow is not organized by the rotation, a transitional flow regime, and a differential flow regime, where the flow is strongly organized into differential rotation with multiple jets. A scaling law is determined based on the convective Rossby number and the density contrast across the equatorial plane, providing a simple way to determine in which regime a given body lies. While a giant planet such as Jupiter lies firmly in the differential flow regime as expected, the Earth's outer core is also found to lie in the differential flow regime indicating that, even in the Earth's outer core, where the density contrast is small, vorticity contributions via fluid movement through the density stratification may be non-negligible.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012E%26PSL.317....1E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012E%26PSL.317....1E"><span>Simulating rotating fluid bodies: When is vorticity generation via density-stratification important?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evonuk, M.; Samuel, H.</p> <p>2012-02-01</p> <p>Differential rotation is one of the key components needed to maintain a magnetic dynamo, therefore it is important to understand the processes that generate differential rotation in rotating bodies. In a rotating density-stratified fluid, local vorticity generation occurs as fluid parcels move radially, expanding or contracting with respect to the background density stratification. The convergence of this vorticity forms zonal flow structures as a function of the radius and the slope of the background density profile. While this effect is thought to be of importance in bodies that are quickly rotating and highly turbulent with large density stratifications such as Jupiter, it is generally neglected in bodies such as the Earth's outer core, where the density change is small. Simulations of thermal convection in the 2D rotating equatorial plane are conducted to determine the parameter regime where local vorticity generation plays a significant role in organizing the fluid flow. Three regimes are found: a dipolar flow regime, where the flow is not organized by the rotation, a transitional flow regime, and a differential flow regime, where the flow is strongly organized into differential rotation with multiple jets. A scaling law is determined based on the convective Rossby number and the density contrast across the equatorial plane, providing a simple way to determine in which regime a given body lies. While a giant planet such as Jupiter lies firmly in the differential flow regime as expected, the Earth's outer core is also found to lie in the differential flow regime indicating that, even in the Earth's outer core, where the density contrast is small, vorticity contributions via fluid movement through the density stratificationmay be non-negligible.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150000127','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150000127"><span>Flow Field and Acoustic Predictions for Three-Stream Jets</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simmons, Shaun Patrick; Henderson, Brenda S.; Khavaran, Abbas</p> <p>2014-01-01</p> <p>Computational fluid dynamics was used to analyze a three-stream nozzle parametric design space. The study varied bypass-to-core area ratio, tertiary-to-core area ratio and jet operating conditions. The flowfield solutions from the Reynolds-Averaged Navier-Stokes (RANS) code Overflow 2.2e were used to pre-screen experimental models for a future test in the Aero-Acoustic Propulsion Laboratory (AAPL) at the NASA Glenn Research Center (GRC). Flowfield solutions were considered in conjunction with the jet-noise-prediction code JeNo to screen the design concepts. A two-stream versus three-stream computation based on equal mass flow rates showed a reduction in peak turbulent kinetic energy (TKE) for the three-stream jet relative to that for the two-stream jet which resulted in reduced acoustic emission. Additional three-stream solutions were analyzed for salient flowfield features expected to impact farfield noise. As tertiary power settings were increased there was a corresponding near nozzle increase in shear rate that resulted in an increase in high frequency noise and a reduction in peak TKE. As tertiary-to-core area ratio was increased the tertiary potential core elongated and the peak TKE was reduced. The most noticeable change occurred as secondary-to-core area ratio was increased thickening the secondary potential core, elongating the primary potential core and reducing peak TKE. As forward flight Mach number was increased the jet plume region decreased and reduced peak TKE.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9276B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9276B"><span>Precession of a two-layer Earth: contributions of the core and elasticity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baenas, Tomás; Ferrándiz, José M.; Escapa, Alberto; Getino, Juan; Navarro, Juan F.</p> <p>2016-04-01</p> <p>The Earth's internal structure contributes to the precession rate in a small but non-negligible amount, given the current accuracy goals demanded by IAG/GGOS to the reference frames, namely 30 μas and 3 μas/yr. These contributions come from a variety of sources. One of those not yet accounted for in current IAU models is associated to the crossed effects of certain nutation-rising terms of a two-layer Earth model; intuitively, it gathers an 'indirect' effect of the core via the NDFW, or FCN, resonance as well as a 'direct' effect arising from terms that account for energy variations depending on the elasticity of the core. Similar order of magnitude reaches the direct effect of the departure of the Earth's rheology from linear elasticity. To compute those effects we work out the problem in a unified way within the Hamiltonian framework developed by Getino and Ferrándiz (2001). It allows a consistent treatment of the problem since all the perturbations are derived from the same tide generating expansion and the crossing effects are rigorously obtained through Hori's canonical perturbation method. The problem admits an asymptotic analytical solution. The Hamiltonian is constructed by considering a two-layer Earth model made up of an anelastic mantle and a fluid core, perturbed by the gravitational action of the Moon and the Sun. The former effects reach some tens of μas/yr in the longitude rate, hence above the target accuracy level. We outline their influence in the estimation of the Earth's dynamical ellipticity, a main parameter factorizing both precession and nutation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRB..122..560C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRB..122..560C"><span>Dynamics of axial torsional libration under the mantle-inner core gravitational interaction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chao, B. F.</p> <p>2017-01-01</p> <p>The aims of this paper are (i) formulating the dynamics of the mantle-inner core gravitational (MICG) interaction in terms of the spherical-harmonic multipoles of mass density. The modeled MICG system is composed of two concentric rigid bodies (mantle and inner core) of near-spherical but otherwise heterogeneous configuration, with a fluid outer core in between playing a passive role. We derive the general equation of motion for the vector rotation but only focus on the polar component that describes the MICG axial torsional libration. The torsion constant and hence the square of the natural frequency of the libration is proportional to the product of the equatorial ellipticities of the mantle and inner-core geoid embodied in their multipoles (of two different types) of degree 2 and order 2 (such as the Large Low-Shear-Velocity Provinces above the core-mantle boundary) and (ii) studying the geophysical implications upon equating the said MICG libration to the steady 6 year oscillation that are observed in the Earth's spin rate or the length-of-day variation (ΔLOD). In particular, the MICG torsion constant is found to be Γ>˜z = CIC σz2 ≈ 6.5 × 1019 N m, while the inner core's (BIC - AIC) ≈ 1.08 × 1031 kg m2 gives the inner core triaxiality (BIC - AIC)/CIC ≈ 1.8 × 10-4, about 8 times the whole-Earth value. It is also asserted that the required inner-core ellipticity amounts to no more than 140 m in geoid height, much smaller than the sensitivity required for the seismic wave travel time to resolve the variation of the inner core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16060164','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16060164"><span>Supercritical fluid technology of nanoparticle coating for new ceramic materials.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aymonier, Cyril; Elissalde, Catherine; Reveron, Helen; Weill, François; Maglione, Mario; Cansell, François</p> <p>2005-06-01</p> <p>This work highlights, for the first time, the coating of ferroelectric nanoparticles with a chemical fluid deposition process in supercritical fluids. BaTiO3 nanoparticles of about 50 nm are coated with a shell of a few nanometers of amorphous alumina and can be recovered as a dry powder for processing. The sintering of these core-shell nanoparticles gives access to a ceramic material with very interesting ferroelectric properties, in particular, dielectric losses below 1%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5116551','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5116551"><span>Vortex Analysis of Intra-Aneurismal Flow in Cerebral Aneurysms</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sunderland, Kevin; Haferman, Christopher; Chintalapani, Gouthami</p> <p>2016-01-01</p> <p>This study aims to develop an alternative vortex analysis method by measuring structure ofIntracranial aneurysm (IA) flow vortexes across the cardiac cycle, to quantify temporal stability of aneurismal flow. Hemodynamics were modeled in “patient-specific” geometries, using computational fluid dynamics (CFD) simulations. Modified versions of known λ 2 and Q-criterion methods identified vortex regions; then regions were segmented out using the classical marching cube algorithm. Temporal stability was measured by the degree of vortex overlap (DVO) at each step of a cardiac cycle against a cycle-averaged vortex and by the change in number of cores over the cycle. No statistical differences exist in DVO or number of vortex cores between 5 terminal IAs and 5 sidewall IAs. No strong correlation exists between vortex core characteristics and geometric or hemodynamic characteristics of IAs. Statistical independence suggests this proposed method may provide novel IA information. However, threshold values used to determine the vortex core regions and resolution of velocity data influenced analysis outcomes and have to be addressed in future studies. In conclusions, preliminary results show that the proposed methodology may help give novel insight toward aneurismal flow characteristic and help in future risk assessment given more developments. PMID:27891172</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27891172','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27891172"><span>Vortex Analysis of Intra-Aneurismal Flow in Cerebral Aneurysms.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sunderland, Kevin; Haferman, Christopher; Chintalapani, Gouthami; Jiang, Jingfeng</p> <p>2016-01-01</p> <p>This study aims to develop an alternative vortex analysis method by measuring structure ofIntracranial aneurysm (IA) flow vortexes across the cardiac cycle, to quantify temporal stability of aneurismal flow. Hemodynamics were modeled in "patient-specific" geometries, using computational fluid dynamics (CFD) simulations. Modified versions of known λ 2 and Q -criterion methods identified vortex regions; then regions were segmented out using the classical marching cube algorithm. Temporal stability was measured by the degree of vortex overlap (DVO) at each step of a cardiac cycle against a cycle-averaged vortex and by the change in number of cores over the cycle. No statistical differences exist in DVO or number of vortex cores between 5 terminal IAs and 5 sidewall IAs. No strong correlation exists between vortex core characteristics and geometric or hemodynamic characteristics of IAs. Statistical independence suggests this proposed method may provide novel IA information. However, threshold values used to determine the vortex core regions and resolution of velocity data influenced analysis outcomes and have to be addressed in future studies. In conclusions, preliminary results show that the proposed methodology may help give novel insight toward aneurismal flow characteristic and help in future risk assessment given more developments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS53C1229Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS53C1229Y"><span>Sulfur Isotope Fractionation in Marine Pore waters from the Offshore Southwestern Taiwan</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, T. L.; Chen, N. C.; Wang, B. S.; Lin, L. H.; Yang, T. F.; Chen, Y. G.; Shen, C. C.</p> <p>2017-12-01</p> <p>In this study, we selected two marine sediment cores, 474cm C11 and 252cm EN1, with different sulfate reduction rate due to anaerobic oxidation of methane (AOM) in offshore southwestern Taiwan, to clarify the regional sulfur biogeochemical process. Sulfur isotopic composition in pore waters was determined on a multi-collector inductively coupled mass spectrometer, Thermo NEPTUNE, with 2-sigma reproducibility of ±0.18‰. Our results show that correlation between δ34S values of 21.7-40.6‰ and 21.5-54.3‰, and sulfate contents of 7.1-26.6 and 1.2-27.6mM follows a closed system Rayleigh fractionation model above the sulfate-methane transition zone (SMTZ) at depths of 172.5 cm for core C11 and 212.5 cm for core EN1 below sea floor. At the SMTZ, δ34S reaches the summit of 40.6 ‰, followed by a decreasing trend to 16-20‰ at depth of 172.5-470.0 cm for core C11. Our results suggest that sulfur in pore fluids offshore southwestern Taiwan is controlled by multiple processes including microbial sulfate reduction, barite dissolution and clay dehydration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130011183','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130011183"><span>Deleterious Thermal Effects Due To Randomized Flow Paths in Pebble Bed, and Particle Bed Style Reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moran, Robert P.</p> <p>2013-01-01</p> <p>A review of literature associated with Pebble Bed and Particle Bed reactor core research has revealed a systemic problem inherent to reactor core concepts which utilize randomized rather than structured coolant channel flow paths. For both the Pebble Bed and Particle Bed Reactor designs; case studies reveal that for indeterminate reasons, regions within the core would suffer from excessive heating leading to thermal runaway and localized fuel melting. A thermal Computational Fluid Dynamics model was utilized to verify that In both the Pebble Bed and Particle Bed Reactor concepts randomized coolant channel pathways combined with localized high temperature regions would work together to resist the flow of coolant diverting it away from where it is needed the most to cooler less resistive pathways where it is needed the least. In other words given the choice via randomized coolant pathways the reactor coolant will take the path of least resistance, and hot zones offer the highest resistance. Having identified the relationship between randomized coolant channel pathways and localized fuel melting it is now safe to assume that other reactor concepts that utilize randomized coolant pathways such as the foam core reactor are also susceptible to this phenomenon.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V24E..05T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V24E..05T"><span>Tethyan Anhydrite Preserved in the Lower Ocean Crust of the Samail Ophiolite? Evidence from Oman Drilling Project Holes GT1A and 2A</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Teagle, D. A. H.; Harris, M.; Crispini, L.; Deans, J. R.; Cooper, M. J.; Kelemen, P. B.; Alt, J.; Banerjee, N.; Shanks, W. C., III</p> <p>2017-12-01</p> <p>Anhydrite is important in mid-ocean ridge hydrothermal systems because of the high concentrations of calcium and sulfate in modern seawater and anhydrite's retrograde solubility. Because anhydrite hosts many powerful tracers of fluid-rock interactions (87Sr/86Sr, δ18O, δ34S, trace elements, fluid inclusions) it is useful for tracing the chemical evolution of hydrothermal recharge fluids and estimating time-integrated fluid fluxes. Anhydrite can form from heated seawater (>100°C), through water-rock reaction, or by mixing of seawater and hydrothermal fluids. Although abundant in active hydrothermal mounds, and predicted to form from downwelling, warming fluids during convection, anhydrite is rare in drill core from seafloor lavas, sheeted dikes and upper gabbros, with only minor amounts in ODP Holes 504B and 1256D. Because anhydrite can dissolve during weathering, its occurrence in ophiolites is unexpected. Instead, gypsum is present in Macquarie Island lavas and Miocene gypsum fills cavities within the Cretaceous Troodos ore deposits. Thus, the occurrence of numerous anhydrite veins in cores from the gabbroic lower crust of the Samail ophiolite in Oman was unanticipated. To our knowledge, anhydrite in Oman gabbros has not been previously reported. Oman Drilling Project Holes GT1A and GT2A were drilled into the Wadi Gideah section of the Wadi Tayin massif. Both recovered 400 m of continuous core from sections of layered gabbros (GT1) and the foliated-layered gabbro transition (GT2). Anhydrite is present throughout both holes, some in vein networks but more commonly as isolated 1-110 mm veins (>60 mm ave). Anhydrite is mostly the sole vein filling but can occur with greenschist minerals such as epidote, quartz, chlorite and prehnite. Anhydrite commonly exhibits prismatic and bladed textures but can also be capriciously microcrystalline. Though definitive cross cutting relationships are elusive, anhydrite veins cut across some greenschist veins. Anhydrite is deformed in faults with asymmetries consistent with normal senses of shear, suggestive of formation near the ridge, or at least before obduction. Gypsum is also present in both holes, but is clearly late stage and cuts across all earlier vein sets and deformation features. Notably, anhydrite was not observed in core from Hole GT3, in the dike-gabbro transition.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSAES..80..272L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSAES..80..272L"><span>Tourmaline orbicules in peraluminous monzogranites of Argentina: A study case of fluid-rock interaction between leucogranite and country-rock metasediments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lira, Raúl; Poklepovic, María F.</p> <p>2017-12-01</p> <p>Tourmaline orbicules hosted in peraluminous granites are documented worldwide. Seven occurrences were identified in Argentina. Petrography, mineral chemistry, whole-rock geochemistry mass balance and microthermometric studies were performed in orbicules formed at the cupola of a peraluminous A-type leucogranite (Los Riojanos pluton), as well as complementary investigation was achieved in other orbicules of similar geological setting. Mass balance computations in zoned orbicules consistently confirmed immobility of Si both in core and halo, immobility of K and little loss of Al during halo reactions. Elements gained and lost in the schorl-rich core are Fe, Al, Mg, Ti, Ba, Sr, Y and Zr, and Na, K, Rb and Nb, respectively; in the halo, K, Ba, Sr, Y, Zr and locally CaO, were gained, and Fe, Mg, Na, Al, Rb and Nb were lost. The schorl-rich core is enriched in LREE relative to the leucogranite host. A temperature-salinity plot from fluid inclusion data delineates a magmatic-meteoric mixing trend of diluting salinity with descending temperature. Computed δDH20 values from Los Riojanos orbicule schorl suggest magmatic and magmatic-meteoric mixed origins. In Los Riojanos, mass balance constraints suggest that Fe, Mg, Ba, Sr and metallic traces like Zn and V (±Pb) were most likely derived from country-rock schists and gneisses through fluid-rock exchange reactions. A late magmatic-, volatile-rich- fluid exsolution scenario for the formation of orbicules is envisaged. Schorl crystallization was likely delayed to the latest stages of leucogranite consolidation, not only favored by the high diffusivity of B2O3 preferentially partitioned into the exsolved aqueous-rich fluid, but also likely limited to the low availability of Fe and Mg from the scarce granitic biotite, and to the high F- content of the melt. The spatial confination of orbicules to the contact zone granite-metasediments suggests that orbicules were not formed until exsolved fluids reached the boundary with the biotite-rich country-rock.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNG14A..08L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNG14A..08L"><span>Laboratory experiments on liquid fragmentation during Earth's core formation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Landeau, M.; Deguen, R.; Olson, P.</p> <p>2013-12-01</p> <p>Buoyancy-driven fragmentation of one liquid in another immiscible liquid likely occurred on a massive scale during the formation of the Earth, when dense liquid metal blobs were released within deep molten silicate magma oceans. Another example of this phenomenon is the sudden release of petroleum into the ocean during the Deepwater Horizon disaster (Gulf of Mexico, 2010). We present experiments on the instability and fragmentation of blobs of a heavy liquid released into a lighter immiscible liquid. During the fragmentation process, we observe deformation of the released fluid, formation of filamentary structures, capillary instability, and eventually drop formation. We find that, at low and intermediate Weber numbers (which measures the importance of inertia versus surface tension), the fragmentation regime mainly results from the competition between a Rayleigh-Taylor instability and the roll-up of a vortex ring. At sufficiently high Weber numbers (the relevant regime for core formation), the fragmentation process becomes turbulent. The large-scale flow then behaves as a turbulent vortex ring or a turbulent thermal: it forms a coherent structure whose shape remains self-similar during the fall and which grows by turbulent entrainment of ambient fluid. An integral model based on the entrainment assumption, and adapted to buoyant vortex rings with initial momentum, is consistent with our experimental data. This indicates that the concept of turbulent entrainment is valid for non-dispersed immiscible fluids at large Weber and Reynolds numbers. Series of photographs, turbulent fragmentation regime, time intervals of about 0.2 s. Portions (red boxes) have been magnified (on the right).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024813','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024813"><span>Pockmarks off Big Sur, California</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Paull, C.; Ussler, W.; Maher, N.; Greene, H. Gary; Rehder, G.; Lorenson, T.; Lee, H.</p> <p>2002-01-01</p> <p>A pockmark field was discovered during EM-300 multi-beam bathymetric surveys on the lower continental slope off the Big Sur coast of California. The field contains ??? 1500 pockmarks which are between 130 and 260 m in diameter, and typically are 8-12 m deep located within a 560 km2 area. To investigate the origin of these features, piston cores were collected from both the interior and the flanks of the pockmarks, and remotely operated vehicle observation (ROV) video and sampling transects were conducted which passed through 19 of the pockmarks. The water column within and above the pockmarks was sampled for methane concentration. Piston cores and ROV collected push cores show that the pockmark field is composed of monotonous fine silts and clays and the cores within the pockmarks are indistinguishable from those outside the pockmarks. No evidence for either sediment winnowing or diagenetic alteration suggestive of fluid venting was obtained. 14C measurements of the organic carbon in the sediments indicate continuous sedimentation throughout the time resolution of the radiocarbon technique ( ??? 45000 yr BP), with a sedimentation rate of ??? 10 cm per 1000 yr both within and between the pockmarks. Concentrations of methane, dissolved inorganic carbon, sulfate, chloride, and ammonium in pore water extracted from within the cores are generally similar in composition to seawater and show little change with depth, suggesting low biogeochemical activity. These pore water chemical gradients indicate that neither significant accumulations of gas are likely to exist in the shallow subsurface ( ??? 100 m) nor is active fluid advection occurring within the sampled sediments. Taken together the data indicate that these pockmarks are more than 45000 yr old, are presently inactive, and contain no indications of earlier fluid or gas venting events. ?? 2002 Elsevier Science B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JIEIC..98..595M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JIEIC..98..595M"><span>Optimization of Simplex Atomizer Inlet Port Configuration through Computational Fluid Dynamics and Experimental Study for Aero-Gas Turbine Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marudhappan, Raja; Chandrasekhar, Udayagiri; Hemachandra Reddy, Koni</p> <p>2017-10-01</p> <p>The design of plain orifice simplex atomizer for use in the annular combustion system of 1100 kW turbo shaft engine is optimized. The discrete flow field of jet fuel inside the swirl chamber of the atomizer and up to 1.0 mm downstream of the atomizer exit are simulated using commercial Computational Fluid Dynamics (CFD) software. The Euler-Euler multiphase model is used to solve two sets of momentum equations for liquid and gaseous phases and the volume fraction of each phase is tracked throughout the computational domain. The atomizer design is optimized after performing several 2D axis symmetric analyses with swirl and the optimized inlet port design parameters are used for 3D simulation. The Volume Of Fluid (VOF) multiphase model is used in the simulation. The orifice exit diameter is 0.6 mm. The atomizer is fabricated with the optimized geometric parameters. The performance of the atomizer is tested in the laboratory. The experimental observations are compared with the results obtained from 2D and 3D CFD simulations. The simulated velocity components, pressure field, streamlines and air core dynamics along the atomizer axis are compared to previous research works and found satisfactory. The work has led to a novel approach in the design of pressure swirl atomizer.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H23C1292M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H23C1292M"><span>The Pore-scale modeling of multiphase flows in reservoir rocks using the lattice Boltzmann method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mu, Y.; Baldwin, C. H.; Toelke, J.; Grader, A.</p> <p>2011-12-01</p> <p>Digital rock physics (DRP) is a new technology to compute the physical and fluid flow properties of reservoir rocks. In this approach, pore scale images of the porous rock are obtained and processed to create highly accurate 3D digital rock sample, and then the rock properties are evaluated by advanced numerical methods at the pore scale. Ingrain's DRP technology is a breakthrough for oil and gas companies that need large volumes of accurate results faster than the current special core analysis (SCAL) laboratories can normally deliver. In this work, we compute the multiphase fluid flow properties of 3D digital rocks using D3Q19 immiscible LBM with two relaxation times (TRT). For efficient implementation on GPU, we improved and reformulated color-gradient model proposed by Gunstensen and Rothmann. Furthermore, we only use one-lattice with the sparse data structure: only allocate memory for pore nodes on GPU. We achieved more than 100 million fluid lattice updates per second (MFLUPS) for two-phase LBM on single Fermi-GPU and high parallel efficiency on Multi-GPUs. We present and discuss our simulation results of important two-phase fluid flow properties, such as capillary pressure and relative permeabilities. We also investigate the effects of resolution and wettability on multiphase flows. Comparison of direct measurement results with the LBM-based simulations shows practical ability of DRP to predict two-phase flow properties of reservoir rock.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S21A2668A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S21A2668A"><span>Are seismic velocity time-lapse changes due to fluid substitution or matrix dissolution? A CO2 sequestration study at Pohokura Field, New Zealand</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adam, L.; Sim, C. Y.; Macfarlane, J.; van Wijk, K.; Shragge, J. C.; Higgs, K.</p> <p>2015-12-01</p> <p>Time-lapse seismic signatures can be used to quantify fluid saturation and pressure changes in a reservoir undergoing CO2 sequestration. However, the injection of CO2 acidifies the water, which may dissolve and/or precipitate minerals. Understanding the impact on the rock frame from field seismic time-lapse changes remains an outstanding challenge. Here, we study the effects of carbonate-CO2-water reactions on the physical and elastic properties of rock samples with variable volumes of carbonate cementation. The effects of fluid substitution alone (brine to CO2) and those due to the combination of fluid substitution and mineral dissolution on time-lapse seismic signatures are studied by combining laboratory data, geophysical well-log data and 1-D seismic modeling. Nine rocks from Pohokura Field (New Zealand) are reacted with carbonic acid. The elastic properties are measured using a high-density laser-ultrasonic setup. We observe that P-wave velocity changes up to -19% and correlate with sandstone grain size. Coarse-grained sandstones show greater changes in elastic wave velocities due to dissolution than fine-grained sandstones. To put this in perspective, this velocity change is comparable to the effect of fluid substitution from brine to CO2. This can potentially create an ambiguity in the interpretation of the physical processes responsible for time-lapse signatures in a CO2injection scenario. The laboratory information is applied onto well-log data to model changes in elastic properties of sandstones at the well-log scale. Well-logs and core petrographic analyses are used to find an elastic model that best describes the observed elastic waves velocities in the cemented reservoir sandstones. The Constant-cement rock physics model is found to predict the elastic behaviour of the cemented sandstones. A possible late-time sequestration scenario is that both mineral dissolution and fluid substitution occur in the reservoir. 1-D synthetic seismograms show that seismic amplitudes can change up to 126% in such a scenario. Our work shows that it is important to consider that time-lapse seismic signatures in carbonate-cemented reservoirs can result not only from fluid and pressure changes but also potentially from chemical reaction between CO2-water mixtures and carbonate cemented sandstones.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ThEng..64..372Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ThEng..64..372Z"><span>Modeling of natural acoustic frequencies of a gas-turbine plant combustion chamber</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zubrilin, I. A.; Gurakov, N. I.; Zubrilin, R. A.; Matveev, S. G.</p> <p>2017-05-01</p> <p>The paper presents results of determination of natural acoustic frequencies of a gas-turbine plant annular combustion chamber model using 3D-simulation. At the beginning, a calculation procedure for determining natural acoustic frequencies of the gas-turbine plant combustion chamber was worked out. The effect of spatial inhomogeneity of the flow parameters (fluid composition, pressure, temperature) arising in combustion and some geometrical parameters (cooling holes of the flame tube walls) on the calculation results is studied. It is found that the change of the fluid composition in combustion affects the acoustic velocity not more than 5%; therefore, the air with a volume variable temperature can be taken as a working fluid in the calculation of natural acoustic frequencies. It is also shown that the cooling holes of the flame tube walls with diameter less than 2 mm can be neglected in the determination of the acoustic modes in the frequency range of up to 1000 Hz. This reduces the number of the grid-model elements by a factor of six in comparison with a model that considers all of the holes. Furthermore, a method of export of spatial inhomogeneity of the flow parameters from a CFD solver sector model to the annular combustion chamber model in a modal solver is presented. As a result of the obtained model calculation, acoustic modes of the combustion chamber in the frequency range of up to 1000 Hz are determined. For a standard engine condition, a potentially dangerous acoustic mode with a frequency close to the ripple frequency of the precessing vortex core, which is formed behind the burner device of this combustion chamber, is detected.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CoPhC.219..121H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CoPhC.219..121H"><span>Cost efficient CFD simulations: Proper selection of domain partitioning strategies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haddadi, Bahram; Jordan, Christian; Harasek, Michael</p> <p>2017-10-01</p> <p>Computational Fluid Dynamics (CFD) is one of the most powerful simulation methods, which is used for temporally and spatially resolved solutions of fluid flow, heat transfer, mass transfer, etc. One of the challenges of Computational Fluid Dynamics is the extreme hardware demand. Nowadays super-computers (e.g. High Performance Computing, HPC) featuring multiple CPU cores are applied for solving-the simulation domain is split into partitions for each core. Some of the different methods for partitioning are investigated in this paper. As a practical example, a new open source based solver was utilized for simulating packed bed adsorption, a common separation method within the field of thermal process engineering. Adsorption can for example be applied for removal of trace gases from a gas stream or pure gases production like Hydrogen. For comparing the performance of the partitioning methods, a 60 million cell mesh for a packed bed of spherical adsorbents was created; one second of the adsorption process was simulated. Different partitioning methods available in OpenFOAM® (Scotch, Simple, and Hierarchical) have been used with different numbers of sub-domains. The effect of the different methods and number of processor cores on the simulation speedup and also energy consumption were investigated for two different hardware infrastructures (Vienna Scientific Clusters VSC 2 and VSC 3). As a general recommendation an optimum number of cells per processor core was calculated. Optimized simulation speed, lower energy consumption and consequently the cost effects are reported here.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019035','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019035"><span>San Andreas fault zone drilling project: scientific objectives and technological challenges</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hickman, S.H.; Younker, L.W.; Zoback, M.D.</p> <p>1995-01-01</p> <p>We are leading a new international initiative to conduct scientific drilling within the San Andreas fault zone at depths of up to 10 km. This project is motivated by the need to understand the physical and chemical processes operating within the fault zone and to answer fundamental questions about earthquake generation along major plate-boundary faults. Through a comprehensive program of coring, fluid sampling, downhole measurements, laboratory experimentation, and long-term monitoring, we hope to obtain critical information on the structure, composition, mechanical behavior and physical state of the San Andreas fault system at depths comparable to the nucleation zones of great earthquakes. The drilling, sampling and observational requirements needed to ensure the success of this project are stringent. These include: 1) drilling stable vertical holes to depths of about 9 km in fractured rock at temperatures of up to 300°C; 2) continuous coring and completion of inclined holes branched off these vertical boreholes to intersect the fault at depths of 3, 6, and 9 km; 3) conducting sophisticated borehole geophysical measurements and fluid/rock sampling at high temperatures and pressures; and 4) instrumenting some or all of these inclined core holes for continuous monitoring of earthquake activity, fluid pressure, deformation and other parameters for periods of up to several decades. For all of these tasks, because of the overpressured clay-rich formations anticipated within the fault zone at depth, we expect to encounter difficult drilling, coring and hole-completion conditions in the region of greatest scientific interest.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhyA..314..539Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhyA..314..539Z"><span>Competition between crystallization and glassification for particles with short-ranged attraction. Possible applications to protein crystallization</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zaccarelli, E.; Sciortino, F.; Tartaglia, P.; Foffi, G.; McCullagh, G. D.; Lawlor, A.; Dawson, K. A.</p> <p>2002-11-01</p> <p>We discuss the phase behaviour of spherical hard-core particles, with an attractive potential, as described by a hard-core Yukawa model. The ratio of the range of the attraction to the diameter of the particles is an important control parameter of the problem. Upon decreasing the range of the attraction, the phase diagram changes quite significantly, with the liquid-gas transition becoming metastable, and the crystal being in equilibrium with the fluid, with no intervening liquid. We also study the glass transition lines and, crucially, find that the situation, being very simple for pure repulsive potentials, becomes much richer in competition between glass and crystal phases for short-range attractions. Also a transition between attractive and repulsive glass appears somewhat in analogy with the isostructural equilibrium transition between two crystals.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T41B0620R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T41B0620R"><span>On the Role of Subduction Dynamics on Emplacement of Metamorphic Core Complexes and Geothermal Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roche, V. M.; Sternai, P.; Guillou-Frottier, L.; Menant, A.; Jolivet, L.; Bouchot, V.; Gerya, T.</p> <p>2017-12-01</p> <p>Subduction-induced extensional tectonics in back-arc domains results in the development of metamorphic core complexes (MCCs) and low-angle normal faults (detachments) that also control magma ascent and fluid circulation. However, possible links with the genesis of high-enthalpy geothermal resources (HEGRs) remain barely explored, and no unifying mechanism responsible for both the generation of MCCs and emplacement of HEGRs has yet been recognized. Although discussions on the possible role of magmatic intrusions beneath these systems are still active, another source of heat is required when one considers the scale of a geothermal Province. An additional source of heat, for instance, could arise from the deep dynamics implied by large-scale tectonic processes such as subduction. Firstly, we investigate subduction dynamics through 3D numerical geodynamic models involving slab rollback and tearing constrained primarily by, geothermal anomaly measurements from western Turkey. Our results show that subduction-induced extensional tectonics controls the genesis and distribution of crustal-scale thermal domes, analogous to crustal and lithospheric boudinage. The thermal domes weaken the crust, localize deformation and enhance development of crustal-scale detachments. Thus, these thermo-mechanical instabilities primarily trigger and control the distribution of MCCs. In addition, subduction-related asthenospheric return flow and shear heating in the mantle increase the temperature of the Moho by up to 250°C. Such forcing is observed in natural settings such as the Menderes (western Anatolia) and the Basin and Range (Western United States). Secondly, the numerically-obtained subduction-induced thermal signature at the base of the continental crust is then imposed as basal thermal condition for 2D high-resolution crustal models dedicated to the understanding of fluid flow around detachments. Our results show that permeable detachments control the bulk of the heat transport and fluid circulation patterns at shallow depth, thus creating favourable zones for HEGRS, as illustrated in the Menderes Massif and in the Basin & Range province.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999APS..DFD..JD09M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999APS..DFD..JD09M"><span>Spiral Convection Columns: Improved Estimate Of Apparent Rotation Period(=1333.6 yr) Of Earth's Solid Inner Core</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDonald, Keith L.</p> <p>1999-11-01</p> <p>In 1974, an est. was made of turbulence driven rot. period of Earth's inner core(r=R_ic), neglecting forced precession, nutation and assuming core fluid's turbulent differential rot., (T_1c^o)_α, alone drives inner core and has achieved steady state so that viscous boundary condition, Υ_φ(R_ic,θ)=ɛ Υ = Υ_ic - Υ = Υ_φ(R_ic), is closely achieved.^1 Υ is mantle's const. sidereal angular velocity, Υ_ic is inner core's, and Υ_φ(r,θ) is fluid's appar., about Z-axis. In 1st est.^1 we assumed velocity and magnetic modes T_α,P_α and T_β,P_β are stationary random functions of time and deleted classes of modes in simplifying toroidal component eq. of transformed amplification eq.,^2 evaluated for mode (T_2c^o)_β to compute radial function (T_1c^o)_α thru a single integration with respect to r. In making integration we assumed toroidal and poloidal B-field intensities have same radial dependency thru core fluid, R_ic <= r <= 0.9R_c, whereas toroidal mag. field declines monotonely as rarrow 0, where it vanishes. To correct discrepancy, divide T_2c^o(r)_β by f(r) and multiply dr by f(r) and integrate over R_ic,..., R_c; define f(r)=150 gauss × (r/0.9R_c), 0 <= r <= 0.9Rc and f(r)=1500(1-r/R_c) gauss for 0.9Rc <= r <= R_c. Repeating computations^1 gives, for νm = 0.2 × 10^5 esu, rot. period of τ _φ(R_ic)=1768.77 yr, instead of former 812 yr.^1 However, we adopted later Elsasser's 1956 est. electrical conductivity of core fluid, σ = 3 × 10-6 emu, which yields τ_φ=1333.6 yr, as close lower limit since σ continues to increase with depth below mantle's base, R_c. Adopting 0.03 cm sec-1 for upwelling motions we see that spiral motions result that do not influence lifetimes of polar heat sources at Rc but shorten to near 10^3 yr near equator. B_T-,B_P-field replaces turbulance theory to compute τ _φ. ^1 Keith L McDonald, Bul. Am. Phys. Soc., 19(10), 1148, 1974. ^2 K L McDonald, On The Planetary Dynamo Theory, ESSA Tech. Report ERL 64-ESL 3 (Govt. Printing Office, 1968), Eq. 21.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1015249','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1015249"><span>Nuclear reactor downcomer flow deflector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gilmore, Charles B [Greensburg, PA; Altman, David A [Pittsburgh, PA; Singleton, Norman R [Murrysville, PA</p> <p>2011-02-15</p> <p>A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGP23A0910E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGP23A0910E"><span>Paleomagnetism and alteration of lower Paleozoic rocks and Precambrian basement in the SHADS No. 4 drill core, Oklahoma</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evans, S. C.; Hamilton, M.; Hardwick, J.; Terrell, C.; Elmore, R. D.</p> <p>2017-12-01</p> <p>The chacterization of the lower Paleozoic sedimentary rock and the underlying Precambrian basement in northern Oklahoma is currently the subject of research to better understand induced seismicity in Oklahoma. We are investigating approximately 140 meters of igneous basement and over 300 meters of Ordovician Arbuckle Group carbonates and underlying sandstone in the Amoco SHADS No. 4 drill core from Rogers Co., Oklahoma, to better understand the nature, origin, and timing of fluid alteration and the relationship between fluid flow in the Arbuckle Group and the basement. Preliminary attempts to orient the core using the viscous remanent magnetization (VRM) method were unsuccessful, probably due to a steep drilling-induced component. The dolomitized Arbuckle Group contains a characteristic remanent magnetization (ChRM) with shallow inclinations (-5°) and variable declinations that, based on unblocking temperatures, is interpreted to reside in magnetite. This ChRM is interpreted as a chemical remanent magnetization (CRM) acquired in the Permian based on the shallow inclinations. The CRM could be related to hydrothermal fluids which migrated into the rocks in the late Paleozoic, as other studies in northern Oklahoma have reported. The Arbuckle Group dolomites are porous and extensively altered and consist of several generations of dolomite, including baroque dolomite. The basement rock is andesitic to trachytic ignimbrite that exhibits extensive alteration. There are many near-vertical fractures mineralized with epidote that are cross cut by calcite-filled fractures. Anisotropy of magnetic susceptibility (AMS) measurements indicate an oblate fabric in the top of the basement and the overlying sandstones. At greater depths, the AMS is variable and may include both alteration and primary fabrics. Demagnetization of the basement rocks is in the initial stages. We are currently investigating if and how far the alteration in the Arbuckle Group extended into the basement. The results suggest basement and sedimentary rock in the core were altered by multiple fluids, and the pervasive fracturing in the igneous section could provide conduits for fluids to get from the porous Arbuckle Group into the basement.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3017490','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3017490"><span>Core Temperature and Sweat Responses in Professional Women's Tennis Players During Tournament Play in the Heat</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tippet, Melissa L.; Stofan, John R.; Lacambra, Magie; Horswill, Craig A.</p> <p>2011-01-01</p> <p>Abstract Context: Tennis is often played in hot, humid environments, intensifying the thermoregulatory strain placed on the athletes. As a safety measure, some tennis organizations allow for a 10-minute break in play between the second and third sets when environmental conditions are extreme. However, the actual effect of these breaks in reducing core temperature is unknown. Objective: To determine change in core temperature after a 10-minute break in play and assess fluid balance in professional female tennis players during tournament matches in the heat. Design: Cross-sectional study. Setting: A Women's Tennis Association Tour–sanctioned outdoor tournament on hard courts under hot conditions (30.3°C ± 2.3°C). Patients or Other Participants: Seven professional tennis players. Main Outcome Measure(s): Change in core temperature after a 10-minute break in tournament play, fluid intake, and sweat losses during match play. Results: Core temperature was reduced from 38.92°C to 38.67°C (change of −0.25°C ± 0.20°C) when a break was taken (P = .02). Mean sweat rate during match play was 2.0 ± 0.5 L/h. During that time, mean fluid intake was 1.5 ± 0.5 L/h, resulting in a 1.2% ± 1.0% reduction in body mass. Conclusions: Female professional tennis players are subjected to high heat loads during match play in hot environments. However, a 10-minute break in play decreased core temperature in 6 of 7 players by an average of 0.25°C, indicating that the break provides practical benefits in the field. Furthermore, although mean sweat rate in this group of female tennis players was high, most athletes were still able to minimize mass loss to less than 2% of their prematch weight. PMID:21214351</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T52B..01H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T52B..01H"><span>The microstructural character and evolution of fault rocks from the SAFOD core and potential weakening mechanisms along the San Andreas Fault (Invited)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holdsworth, R. E.; van Diggelen, E.; Spiers, C.; de Bresser, J. H.; Smith, S. A.</p> <p>2009-12-01</p> <p>In the region of the SAFOD borehole, the San Andreas Fault (SAF) separates two very different geological terranes referred to here as the Salinian and Great Valley blocks (SB, GVB). The three sections of core preserve a diverse range of fault rocks and pass through the two currently active, highly localised slipping sections, the so-called ‘10480’ and ‘10830’ fault zones . These coincide with a broader region - perhaps as much as 100m wide - of high strain fault rocks formed at some time in the geological past, but now currently inactive. Both the slipping segments and older high strain zone(s) are developed in the GVB located NE of the terrane boundary. This is likely influenced by the phyllosilicate-rich protolith of the GVB and the large volume of trapped fluid known to exist NE and below the SAF in this region. Microstructurally, lower strain domains (most of Core 1 cutting the SB, significant parts of Core 3 cutting the GVB) preserve clear evidence for classic upper crustal cataclastic brittle faulting processes and associated fluid flow. The GVB in particular shows clear geological evidence for both fluid pressure and differential stress cycling (variable modes of hydrofacture associated with faults) during seismicity. There is also some evidence in all minor faults for the operation of limited amounts of solution-precipitation creep. High strain domains (much of Core 2 cutting the GVB, parts of Core 3 adjacent to the 10830 fault) are characterised by the development of foliated cataclasites and gouge largely due to the new growth of fine-grained phyllosilicate networks (predominantly smectite-bearing mixed layer clays, locally serpentinite, but not talc). The most deformed sections are characterised by the development of shear band fabrics and asymmetric folds. Reworking and reactivation is widespread manifested by: i) the preservation of one or more earlier generations of gouge preserved as clasts; and ii) by the development of later interconnected, polished and striated slip surfaces at low angles or sub-parallel to the foliation. These are coated with thin phyllosilicate films and are closely associated with the development of lozenge, arrow-head and triangular mineral veins (mostly calcite) inferred to be precipitated in dilation sites during slip. The largest displacement gouges also preserve numerous rounded ‘exotic’ clasts. These include serpentinite, crystalline carbonate, anhydrite and quartzofeldspathic units that texturally look very similar to clasts found in the SB. The SAFOD core fault rocks highlight the fundamental role played by fluid-rock interactions in upper crustal fault zones. There is clear evidence for the development of high pore fluid pressures (hydrofracture development), reaction weakening (phyllosilicate growth following cataclasis) and geometric weakening due to the development of weak interconnected layers (foliations, polished striated slip surfaces). There are also very significant similarities between the fault rocks seen here and those preserved along other deeply exhumed weak fault elsewhere in the world.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992JChPh..96.1507Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992JChPh..96.1507Z"><span>Chemical association in simple models of molecular and ionic fluids. III. The cavity function</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Yaoqi; Stell, George</p> <p>1992-01-01</p> <p>Exact equations which relate the cavity function to excess solvation free energies and equilibrium association constants are rederived by using a thermodynamic cycle. A zeroth-order approximation, derived previously by us as a simple interpolation scheme, is found to be very accurate if the associative bonding occurs on or near the surface of the repulsive core of the interaction potential. If the bonding radius is substantially less than the core radius, the approximation overestimates the association degree and the association constant. For binary association, the zeroth-order approximation is equivalent to the first-order thermodynamic perturbation theory (TPT) of Wertheim. For n-particle association, the combination of the zeroth-order approximation with a ``linear'' approximation (for n-particle distribution functions in terms of the two-particle function) yields the first-order TPT result. Using our exact equations to go beyond TPT, near-exact analytic results for binary hard-sphere association are obtained. Solvent effects on binary hard-sphere association and ionic association are also investigated. A new rule which generalizes Le Chatelier's principle is used to describe the three distinct forms of behaviors involving solvent effects that we find. The replacement of the dielectric-continuum solvent model by a dipolar hard-sphere model leads to improved agreement with an experimental observation. Finally, equation of state for an n-particle flexible linear-chain fluid is derived on the basis of a one-parameter approximation that interpolates between the generalized Kirkwood superposition approximation and the linear approximation. A value of the parameter that appears to be near optimal in the context of this application is obtained from comparison with computer-simulation data.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JCoPh.327..700D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JCoPh.327..700D"><span>FaCSI: A block parallel preconditioner for fluid-structure interaction in hemodynamics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deparis, Simone; Forti, Davide; Grandperrin, Gwenol; Quarteroni, Alfio</p> <p>2016-12-01</p> <p>Modeling Fluid-Structure Interaction (FSI) in the vascular system is mandatory to reliably compute mechanical indicators in vessels undergoing large deformations. In order to cope with the computational complexity of the coupled 3D FSI problem after discretizations in space and time, a parallel solution is often mandatory. In this paper we propose a new block parallel preconditioner for the coupled linearized FSI system obtained after space and time discretization. We name it FaCSI to indicate that it exploits the Factorized form of the linearized FSI matrix, the use of static Condensation to formally eliminate the interface degrees of freedom of the fluid equations, and the use of a SIMPLE preconditioner for saddle-point problems. FaCSI is built upon a block Gauss-Seidel factorization of the FSI Jacobian matrix and it uses ad-hoc preconditioners for each physical component of the coupled problem, namely the fluid, the structure and the geometry. In the fluid subproblem, after operating static condensation of the interface fluid variables, we use a SIMPLE preconditioner on the reduced fluid matrix. Moreover, to efficiently deal with a large number of processes, FaCSI exploits efficient single field preconditioners, e.g., based on domain decomposition or the multigrid method. We measure the parallel performances of FaCSI on a benchmark cylindrical geometry and on a problem of physiological interest, namely the blood flow through a patient-specific femoropopliteal bypass. We analyze the dependence of the number of linear solver iterations on the cores count (scalability of the preconditioner) and on the mesh size (optimality).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhLA..382.1024E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhLA..382.1024E"><span>Plasma coating of nanoparticles in the presence of an external electric field</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ebadi, Zahra; Pourali, Nima; Mohammadzadeh, Hosein</p> <p>2018-04-01</p> <p>Film deposition onto nanoparticles by low-pressure plasma in the presence of an external electric field is studied numerically. The plasma discharge fluid model along with surface deposition and heating models for nanoparticles, as well as a dynamics model considering the motion of nanoparticles, are employed for this study. The results of the simulation show that applying external field during the process increases the uniformity of the film deposited onto nanoparticles and leads to that nanoparticles grow in a spherical shape. Increase in film uniformity and particles sphericity is related to particle dynamics that is controlled by parameters of the external field like frequency and amplitude. The results of this work can be helpful to produce spherical core-shell nanoparticles in nanomaterial industry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1207..760P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1207..760P"><span>CFD Modeling of a CFB Riser Using Improved Inlet Boundary Conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peng, B. T.; Zhang, C.; Zhu, J. X.; Qi, X. B.</p> <p>2010-03-01</p> <p>A computational fluid dynamics (CFD) model based on Eulerian-Eulerian approach coupled with granular kinetics theory was adopted to investigate the hydrodynamics and flow structures in a circulating fluidized bed (CFB) riser column. A new approach to specify the inlet boundary conditions was proposed in this study to simulate gas-solids flow in CFB risers more accurately. Simulation results were compared with the experimental data, and good agreement between the numerical results and experimental data was observed under different operating conditions, which indicates the effectiveness and accuracy of the CFD model with the proposed inlet boundary conditions. The results also illustrate a clear core annulus structure in the CFB riser under all operating conditions both experimentally and numerically.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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