Experimental and numerical analysis of parallel reactant flow and transverse mixing with mineral precipitation in homogeneous and heterogeneous porous media

DOE PAGES

Fox, Don T.; Guo, Luanjing; Fujita, Yoshiko; ...

2015-12-17

Formation of mineral precipitates in the mixing interface between two reactant solutions flowing in parallel in porous media is governed by reactant mixing by diffusion and dispersion and is coupled to changes in porosity/permeability due to precipitation. The spatial and temporal distribution of mixing-dependent precipitation of barium sulfate in porous media was investigated with side-by-side injection of barium chloride and sodium sulfate solutions in thin rectangular flow cells packed with quartz sand. The results for homogeneous sand beds were compared to beds with higher or lower permeability inclusions positioned in the path of the mixing zone. In the homogeneous andmore » high permeability inclusion experiments, BaSO 4 precipitate (barite) formed in a narrow deposit along the length and in the center of the solution–solution mixing zone even though dispersion was enhanced within, and downstream of, the high permeability inclusion. In the low permeability inclusion experiment, the deflected BaSO 4 precipitation zone broadened around one side and downstream of the inclusion and was observed to migrate laterally toward the sulfate solution. A continuum-scale fully coupled reactive transport model that simultaneously solves the nonlinear governing equations for fluid flow, transport of reactants and geochemical reactions was used to simulate the experiments and provide insight into mechanisms underlying the experimental observations. Lastly, migration of the precipitation zone in the low permeability inclusion experiment could be explained by the coupling effects among fluid flow, reactant transport and localized mineral precipitation reaction.« less

Airborne observation of mixing across the entrainment zone during PARADE 2011

NASA Astrophysics Data System (ADS)

Berkes, Florian; Hoor, Peter; Bozem, Heiko; Kunkel, Daniel; Sprenger, Michael; Henne, Stephan

2016-05-01

This study presents the analysis of the structure and air mass characteristics of the lower atmosphere during the field campaign PARADE (PArticles and RAdicals: Diel observations of the impact of urban and biogenic Emissions) on Mount Kleiner Feldberg in southwestern Germany during late summer 2011. We analysed measurements of meteorological variables (temperature, moisture, pressure, wind speed and direction) from radio soundings and of chemical tracers (carbon dioxide, ozone) from aircraft measurements. We focus on the thermodynamic and dynamic properties that control the chemical distribution of atmospheric constituents in the boundary layer. We show that the evolution of tracer profiles of CO2 and O3 indicate mixing across the inversion layer (or entrainment zone). This finding is supported by the analysis of tracer-tracer correlations which are indicative for mixing and the relation of tracer profiles in relation to the evolution of the boundary layer height deduced from radio soundings. The study shows the relevance of entrainment processes for the lower troposphere in general and specifically that the tracer-tracer correlation method can be used to identify mixing and irreversible exchange processes across the inversion layer.

Analysis of crash proportion by vehicle type at traffic analysis zone level: A mixed fractional split multinomial logit modeling approach with spatial effects.

PubMed

Lee, Jaeyoung; Yasmin, Shamsunnahar; Eluru, Naveen; Abdel-Aty, Mohamed; Cai, Qing

2018-02-01

In traffic safety literature, crash frequency variables are analyzed using univariate count models or multivariate count models. In this study, we propose an alternative approach to modeling multiple crash frequency dependent variables. Instead of modeling the frequency of crashes we propose to analyze the proportion of crashes by vehicle type. A flexible mixed multinomial logit fractional split model is employed for analyzing the proportions of crashes by vehicle type at the macro-level. In this model, the proportion allocated to an alternative is probabilistically determined based on the alternative propensity as well as the propensity of all other alternatives. Thus, exogenous variables directly affect all alternatives. The approach is well suited to accommodate for large number of alternatives without a sizable increase in computational burden. The model was estimated using crash data at Traffic Analysis Zone (TAZ) level from Florida. The modeling results clearly illustrate the applicability of the proposed framework for crash proportion analysis. Further, the Excess Predicted Proportion (EPP)-a screening performance measure analogous to Highway Safety Manual (HSM), Excess Predicted Average Crash Frequency is proposed for hot zone identification. Using EPP, a statewide screening exercise by the various vehicle types considered in our analysis was undertaken. The screening results revealed that the spatial pattern of hot zones is substantially different across the various vehicle types considered. Copyright © 2017 Elsevier Ltd. All rights reserved.

14C age reassessment of groundwater from the discharge zone due to cross-flow mixing in the deep confined aquifer

NASA Astrophysics Data System (ADS)

Mao, Xumei; Wang, Hua; Feng, Liang

2018-05-01

In a groundwater flow system, the age of groundwater should gradually increase from the recharge zone to the discharge zone within the same streamline. However, it is occasionally observed that the groundwater age becomes younger in the discharge zone in the piedmont alluvial plain, and the oldest age often appears in the middle of the plain. A new set of groundwater chemistry and isotopes was employed to reassess the groundwater 14C ages from the discharge zone in the North China Plain (NCP). Carbonate precipitation, organic matter oxidation and cross-flow mixing in the groundwater from the recharge zone to the discharge zone are recognized according to the corresponding changes of HCO3- (or DIC) and δ13C in the same streamline of the third aquifer of the NCP. The effects of carbonate precipitation and organic matter oxidation are calibrated with a 13C mixing model and DIC correction, but these corrected 14C ages seem unreasonable because they grow younger from the middle plain to the discharge zone in the NCP. The relationship of Cl- content and the recharge distance is used to estimate the expected Cl- content in the discharge zone, and ln(a14C)/Cl is proposed to correct the a14C in groundwater for the effect of cross-flow mixing. The 14C ages were reassessed with the corrected a14C due to the cross-flow mixing varying from 1.25 to 30.58 ka, and the groundwater becomes older gradually from the recharge zone to the discharge zone. The results suggest that the reassessed 14C ages are more reasonable for the groundwater from the discharge zone due to cross-flow mixing.

AN EXPERT SYSTEM FOR HYDRODYNAMIC MIXING ZONE ANAYLSIS OF CONVENTIONAL AND TOXIC SUBMERGED SINGLE PORT DISCHARGES (CORMIX1)

EPA Science Inventory

U.S. water quality policy includes the concept of a mixing zone, a limited area or volume of water where the initial dilution of a discharge occurs. he Cornell Mixing Zone Expert System (CORMIX1) was developed to predict the dilution and trajectory of a submerged single port disc...

Examining the Fieldwork Experience from the Site Supervisor Perspective: A Mixed-Methods Study Using Vygotsky's Zone of Proximal Development Theory

ERIC Educational Resources Information Center

Brannon, Sian

2013-01-01

The purpose of this study was to identify feelings and behaviors of fieldwork supervisors in public libraries using Lev Vygotsky's Zone of Proximal Development theory as a background for design, analysis, and discussion of results. This research sought to find out how fieldwork supervisors perform initial assessments of their fieldwork students,…

On the Structure of the Mixing Zone at an Unstable Contact Boundary

NASA Astrophysics Data System (ADS)

Meshkov, E. E.

2018-01-01

The interface between two media of different densities (contact boundary) moving with an acceleration directed from the less dense medium to the more dense one is unstable (Rayleigh-Taylor instability) [1, 2]. The initial perturbations of the interface grow indefinitely and, as a result, a medium mixing zone growing with time is formed at the interface. The structure of such a mixing zone at gas-gas and gas-liquid interfaces is discussed on the basis of laboratory experiments on shock tubes of various types. It is concluded that the regions of turbulent and laminar flows are combined in the mixing zone.

3D mapping, hydrodynamics and modelling of the freshwater-brine mixing zone in salt flats similar to the Salar de Atacama (Chile)

NASA Astrophysics Data System (ADS)

Marazuela, M. A.; Vázquez-Suñé, E.; Custodio, E.; Palma, T.; García-Gil, A.; Ayora, C.

2018-06-01

Salt flat brines are a major source of minerals and especially lithium. Moreover, valuable wetlands with delicate ecologies are also commonly present at the margins of salt flats. Therefore, the efficient and sustainable exploitation of the brines they contain requires detailed knowledge about the hydrogeology of the system. A critical issue is the freshwater-brine mixing zone, which develops as a result of the mass balance between the recharged freshwater and the evaporating brine. The complex processes occurring in salt flats require a three-dimensional (3D) approach to assess the mixing zone geometry. In this study, a 3D map of the mixing zone in a salt flat is presented, using the Salar de Atacama as an example. This mapping procedure is proposed as the basis of computationally efficient three-dimensional numerical models, provided that the hydraulic heads of freshwater and mixed waters are corrected based on their density variations to convert them into brine heads. After this correction, the locations of lagoons and wetlands that are characteristic of the marginal zones of the salt flats coincide with the regional minimum water (brine) heads. The different morphologies of the mixing zone resulting from this 3D mapping have been interpreted using a two-dimensional (2D) flow and transport numerical model of an idealized cross-section of the mixing zone. The result of the model shows a slope of the mixing zone that is similar to that obtained by 3D mapping and lower than in previous models. To explain this geometry, the 2D model was used to evaluate the effects of heterogeneity in the mixing zone geometry. The higher the permeability of the upper aquifer is, the lower the slope and the shallower the mixing zone become. This occurs because most of the freshwater lateral recharge flows through the upper aquifer due to its much higher transmissivity, thus reducing the freshwater head. The presence of a few meters of highly permeable materials in the upper part of these hydrogeological systems, such as alluvial fans or karstified evaporites that are frequently associated with the salt flats, is enough to greatly modify the geometry of the saline interface.

Multiple injected and natural conservative tracers quantify mixing in a stream confluence affected by acid mine drainage near Silverton, Colorado

NASA Astrophysics Data System (ADS)

Schemel, Laurence E.; Cox, Marisa H.; Runkel, Robert L.; Kimball, Briant A.

2006-08-01

The acidic discharge from Cement Creek, containing elevated concentrations of dissolved metals and sulphate, mixed with the circumneutral-pH Animas River over a several hundred metre reach (mixing zone) near Silverton, CO, during this study. Differences in concentrations of Ca, Mg, Si, Sr, and SO42- between the creek and the river were sufficiently large for these analytes to be used as natural tracers in the mixing zone. In addition, a sodium chloride (NaCl) tracer was injected into Cement Creek, which provided a Cl- reference tracer in the mixing zone. Conservative transport of the dissolved metals and sulphate through the mixing zone was verified by mass balances and by linear mixing plots relative to the injected reference tracer. At each of seven sites in the mixing zone, five samples were collected at evenly spaced increments of the observed across-channel gradients, as determined by specific conductance. This created sets of samples that adequately covered the ranges of mixtures (mixing ratios, in terms of the fraction of Animas River water, %AR). Concentratis measured in each mixing zone sample and in the upstream Animas River and Cement Creek were used to compute %AR for the reference and natural tracers. Values of %AR from natural tracers generally showed good agreement with values from the reference tracer, but variability in discharge and end-member concentrations and analytical errors contributed to unexpected outlier values for both injected and natural tracers. The median value (MV) %AR (calculated from all of the tracers) reduced scatter in the mixing plots for the dissolved metals, indicating that the MV estimate reduced the effects of various potential errors that could affect any tracer.

Freshwater-Brine Mixing Zone Hydrodynamics in Salt Flats (Salar de Atacama)

NASA Astrophysics Data System (ADS)

Marazuela, M. A.; Vázquez-Suñé, E.; Custodio, E.; Palma, T.; García-Gil, A.

2017-12-01

The increase in the demand of strategic minerals for the development of medicines and batteries require detailed knowledge of the salt flats freshwater-brine interface to make its exploitation efficient. The interface zone is the result of a physical balance between the recharged and evaporated water. The sharp interface approach assumes the immiscibility of the fluids and thus neglects the mixing between them. As a consequence, for miscible fluids it is more accurate and often needed to use the mixing zone concept, which results from the dynamic equilibrium of flowing freshwater and brine. In this study, we consider two and three-dimensional scale approaches for the management of the mixing zone. The two-dimensional approach is used to understand the dynamics and the characteristics of the salt flat mixing zone, especially in the Salar de Atacama (Atacama salt flat) case. By making use of this model we analyze and quantify the effects of the aquitards on the mixing zone geometry. However, the understanding of the complex physical processes occurring in the salt flats and the management of these environments requires the adoption of three-dimensional regional scale numerical models. The models that take into account the effects of variable density represent the best management tool, but they require large computational resources, especially in the three-dimensional case. In order to avoid these computational limitations in the modeling of salt flats and their valuable ecosystems, we propose a three-step methodology, consisting of: (1) collection, validation and interpretation of the hydrogeochemical data, (2) identification and three-dimensional mapping of the mixing zone on the land surface and in depth, and (3) application of a water head correction to the freshwater and mixed water heads in order to compensate the density variations and to transform them to brine water heads. Finally, an evaluation of the sensibility of the mixing zone to anthropogenic and climate changes is included.

Microstructure and Hydrogen-Induced Failure Mechanisms in Fe and Ni Alloy Weldments

NASA Astrophysics Data System (ADS)

Fenske, J. A.; Robertson, I. M.; Ayer, Raghavan; Hukle, Martin; Lillig, Dan; Newbury, Brian

2012-09-01

The microstructure and fracture morphology of AISI 8630-IN625 and ASTM A182-F22-IN625 dissimilar metal weld interfaces were compared and contrasted as a function of postweld heat treatment (PWHT) duration. For both systems, the microstructure along the weld interface consisted of a coarse grain heat-affected zone in the Fe-base metal followed by discontinuous martensitic partially mixed zones and a continuous partially mixed zone on the Ni side of the fusion line. Within the partially mixed zone on the Ni side, there exists a 200-nm-wide transition zone within a 20- μm-wide planar solidification region followed by a cellular dendritic region with Nb-Mo-rich carbides decorating the dendrite boundaries. Although there were differences in the volume of the partially mixed zones, the major difference in the metal weld interfaces was the presence of M7C3 precipitates in the planar solidification region, which had formed in AISI 8630-IN625 but not in ASTM A182-F22-IN625. These precipitates make the weldment more susceptible to hydrogen embrittlement and provide a low energy fracture path between the discontinuous partially mixed zones.

Dynamics and hydrodynamic mixing of reactive solutes at stable fresh-salt interfaces

NASA Astrophysics Data System (ADS)

van der Zee, Sjoerd E. A. T. M.; Eeman, Sara; Cirkel, Gijsbert; Leijnse, Toon

2014-05-01

In coastal zones with saline groundwater, but also in semi-arid regions, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. A similar situation is found in situations where groundwater is not saline, but has a different chemical signature than rainwater-affected groundwater. Then also, vegetation patches and botanic biodiversity may depend sensitively on the depth of the interface between different types of groundwater. In this presentation, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens properties by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominate on the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalised lens volume and the main lens and recharge characteristics, enabling an empirical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase and the increase of recharge frequency causes a decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the centre of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of irregularly varying daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens characteristics using basic lens and recharge parameters without the use of numerical models. This enables the assessment of the vulnerability of any thin fresh water lens on saline, upward seeping groundwater to salinity stress in the root zone.

Numerical solution of nonlinear partial differential equations of mixed type. [finite difference approximation

NASA Technical Reports Server (NTRS)

Jameson, A.

1976-01-01

A review is presented of some recently developed numerical methods for the solution of nonlinear equations of mixed type. The methods considered use finite difference approximations to the differential equation. Central difference formulas are employed in the subsonic zone and upwind difference formulas are used in the supersonic zone. The relaxation method for the small disturbance equation is discussed and a description is given of difference schemes for the potential flow equation in quasi-linear form. Attention is also given to difference schemes for the potential flow equation in conservation form, the analysis of relaxation schemes by the time dependent analogy, the accelerated iterative method, and three-dimensional calculations.

Phase transformations in an ascending adiabatic mixed-phase cloud volume

NASA Astrophysics Data System (ADS)

Pinsky, M.; Khain, A.; Korolev, A.

2015-04-01

Regimes of liquid-ice coexistence that may form in an adiabatic parcel ascending at constant velocity at freezing temperatures are investigated. Four zones with different microphysical structures succeeding one another along the vertical direction have been established. On the basis of a novel balance equation, analytical expressions are derived to determine the conditions specific for each of these zones. In particular, the necessary and sufficient conditions for formation of liquid water phase within an ascending parcel containing only ice particles are determined. The results are compared to findings reported in earlier studies. The role of the Wegener-Bergeron-Findeisen mechanism in the phase transformation is analyzed. The dependence of the phase relaxation time on height in the four zones is investigated on the basis of a novel analytical expression. The results obtained in the study can be instrumental for analysis and interpretation of observed mixed-phase clouds.

Mixing effects on nitrogen and oxygen concentrations and the relationship to mean residence time in a hyporheic zone of a riffle-pool sequence

USGS Publications Warehouse

Naranjo, Ramon C.; Niswonger, Richard G.; Clinton Davis,

2015-01-01

Flow paths and residence times in the hyporheic zone are known to influence biogeochemical processes such as nitrification and denitrification. The exchange across the sediment-water interface may involve mixing of surface water and groundwater through complex hyporheic flow paths that contribute to highly variable biogeochemically active zones. Despite the recognition of these patterns in the literature, conceptualization and analysis of flow paths and nitrogen transformations beneath riffle-pool sequences often neglect to consider bed form driven exchange along the entire reach. In this study, the spatial and temporal distribution of dissolved oxygen (DO), nitrate (NO3-) and ammonium (NH4+) were monitored in the hyporheic zone beneath a riffle-pool sequence on a losing section of the Truckee River, NV. Spatially-varying hyporheic exchange and the occurrence of multi-scale hyporheic mixing cells are shown to influence concentrations of DO and NO3- and the mean residence time (MRT) of riffle and pool areas. Distinct patterns observed in piezometers are shown to be influenced by the first large flow event following a steady 8 month period of low flow conditions. Increases in surface water discharge resulted in reversed hydraulic gradients and production of nitrate through nitrification at small vertical spatial scales (0.10 to 0.25 m) beneath the sediment-water interface. In areas with high downward flow rates and low MRT, denitrification may be limited. The use of a longitudinal two-dimensional flow model helped identify important mechanisms such as multi-scale hyporheic mixing cells and spatially varying MRT, an important driver for nitrogen transformation in the riverbed. Our observations of DO and NO3- concentrations and model simulations highlight the role of multi-scale hyporheic mixing cells on MRT and nitrogen transformations in the hyporheic zone of riffle-pool sequences. This article is protected by copyright. All rights reserved.

Inflow, Outflow, Yields, and Stellar Population Mixing in Chemical Evolution Models

NASA Astrophysics Data System (ADS)

Andrews, Brett H.; Weinberg, David H.; Schönrich, Ralph; Johnson, Jennifer A.

2017-02-01

Chemical evolution models are powerful tools for interpreting stellar abundance surveys and understanding galaxy evolution. However, their predictions depend heavily on the treatment of inflow, outflow, star formation efficiency (SFE), the stellar initial mass function, the SN Ia delay time distribution, stellar yields, and stellar population mixing. Using flexCE, a flexible one-zone chemical evolution code, we investigate the effects of and trade-offs between parameters. Two critical parameters are SFE and the outflow mass-loading parameter, which shift the knee in [O/Fe]-[Fe/H] and the equilibrium abundances that the simulations asymptotically approach, respectively. One-zone models with simple star formation histories follow narrow tracks in [O/Fe]-[Fe/H] unlike the observed bimodality (separate high-α and low-α sequences) in this plane. A mix of one-zone models with inflow timescale and outflow mass-loading parameter variations, motivated by the inside-out galaxy formation scenario with radial mixing, reproduces the two sequences better than a one-zone model with two infall epochs. We present [X/Fe]-[Fe/H] tracks for 20 elements assuming three different supernova yield models and find some significant discrepancies with solar neighborhood observations, especially for elements with strongly metallicity-dependent yields. We apply principal component abundance analysis to the simulations and existing data to reveal the main correlations among abundances and quantify their contributions to variation in abundance space. For the stellar population mixing scenario, the abundances of α-elements and elements with metallicity-dependent yields dominate the first and second principal components, respectively, and collectively explain 99% of the variance in the model. flexCE is a python package available at https://github.com/bretthandrews/flexCE.

Inflow, Outflow, Yields, and Stellar Population Mixing in Chemical Evolution Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, Brett H.; Weinberg, David H.; Schönrich, Ralph

Chemical evolution models are powerful tools for interpreting stellar abundance surveys and understanding galaxy evolution. However, their predictions depend heavily on the treatment of inflow, outflow, star formation efficiency (SFE), the stellar initial mass function, the SN Ia delay time distribution, stellar yields, and stellar population mixing. Using flexCE, a flexible one-zone chemical evolution code, we investigate the effects of and trade-offs between parameters. Two critical parameters are SFE and the outflow mass-loading parameter, which shift the knee in [O/Fe]–[Fe/H] and the equilibrium abundances that the simulations asymptotically approach, respectively. One-zone models with simple star formation histories follow narrow tracksmore » in [O/Fe]–[Fe/H] unlike the observed bimodality (separate high- α and low- α sequences) in this plane. A mix of one-zone models with inflow timescale and outflow mass-loading parameter variations, motivated by the inside-out galaxy formation scenario with radial mixing, reproduces the two sequences better than a one-zone model with two infall epochs. We present [X/Fe]–[Fe/H] tracks for 20 elements assuming three different supernova yield models and find some significant discrepancies with solar neighborhood observations, especially for elements with strongly metallicity-dependent yields. We apply principal component abundance analysis to the simulations and existing data to reveal the main correlations among abundances and quantify their contributions to variation in abundance space. For the stellar population mixing scenario, the abundances of α -elements and elements with metallicity-dependent yields dominate the first and second principal components, respectively, and collectively explain 99% of the variance in the model. flexCE is a python package available at https://github.com/bretthandrews/flexCE.« less

Impact of tropical cyclone Matmo on mixed zone of the Yellow and Bohai seas

NASA Astrophysics Data System (ADS)

Guo, Jie; Ji, Diansheng; Hou, Chawei; Guo, Kai; Ji, Ling

2017-12-01

The Bohai Sea is a low-lying semi-enclosed sea area that is linked to the Yellow Sea via the Bohai straits (mixed zone). Its off shore seabed is shallow, which makes it vulnerable to serious marine meteorological disasters associated with the northward passage of Pacifi c tropical cyclones. Analyses on data of remote sensing and buoy of the mixed zone of the Yellow and Bohai seas indicate that all the wind speed, signifi cant wave height, and salinity (SAL) increased, sea surface temperature decreased, and wind energy density changed considerably during the passage of tropical cyclone Matmo on July 25, 2014. It was found that the SAL inversion layer in the mixed zone of the Yellow and Bohai Seas was caused by the tropical cyclone. Furthermore, it was found that the tropical cyclone transported the northern Yellow Sea cold water mass (NYSCWM) into the mixed zone of the Yellow and Bohai Seas. The NYSCWM has direct infl uence on both the aquaculture and the ecological environment of the region. Therefore, further research is needed to establish the mechanism behind the formation of the SAL inversion layer in the mixed zone, and to determine the infl uence of tropical cyclones on the NYSCWM.

Recycling and recharge processes at the Hasandağ Stratovolcano, Central Anatolia: Insights on magma chamber systematics from plagioclase textures and zoning patterns

NASA Astrophysics Data System (ADS)

Gall, H. D.; Cipar, J. H.; Crispin, K. L.; Kürkçüoğlu, B.; Furman, T.

2017-12-01

We elucidate crystal recycling and magma recharge processes at Hasandağ by investigating compositional zoning patterns and textural variation in plagioclase crystals from Quaternary basaltic andesite through dacite lavas. Previous work on Hasandağ intermediate compositions identified thermochemical disequilibrium features and showed abundant evidence for magma mixing1,2. We expand on this work through detailed micro-texture and mineral diffusion analysis to explore the mechanisms and timescales of crystal transport and mixing processes. Thermobarometric calculations constrain the plumbing system to 1.2-2 kbar and 850-950°C, corresponding to a felsic magma chamber at 4.5 km. Electron microprobe results reveal plagioclase phenocrysts from all lava types have common core (An33-46) and rim (An36-64) compositions, with groundmass laths (An57-67) resembling the phenocryst rims. Low An cores are ubiquitous, regardless of bulk rock chemistry, and suggest a consistent composition within the magma reservoir prior to high An rim growth. High An rims are regularly enriched in Mg, Fe, Ti and Sr, which we attribute to mafic recharge and magma mixing. We assess mixing timescales by inverse diffusion modeling of Mg profiles across the core-rim boundaries. Initial results suggest mixing to eruption processes occur on the order of days to months. Heterogeneous calculated timescales within thin sections indicate crystal populations with different growth histories. Crystals often display prominent sieve-textured zones just inside the rim, as well as other disequilibrium features such as oscillatory zoning or resorbed and patchy-zoned cores. We interpret these textures to indicate mobilization of a homogeneous dacitic reservoir with abundant An35 plagioclase crystals by frequent injection of mafic magma. Variability in observed textures and calculated timescales manifests during defrosting of a highly crystalline felsic mush, through different degrees of magma mixing. This process results in distinct crystal populations, some of which record punctuated ascent and storage, while others are erupted rapidly after the influx of new magma. Aydar, E., & Gourgaud, A. (1998). J. Volcanol. Geotherm. Res., 85(1), 129-152. Ustunisik, G., & Kilinc, A. (2011). Lithos, 125(3), 984-993.

Investigation with an Interferometer of the Turbulent Mixing of a Free Supersonic Jet

NASA Technical Reports Server (NTRS)

Gooderum, Paul B; Wood, George P; Brevoort, Maurice J

1950-01-01

The free turbulent mixing of a supersonic jet of Mach number 1.6 has been experimentally investigated. An interferometer, of which a description is given, was used for the investigation. Density and velocity distributions through the mixing zone have been obtained. It was found that there was similarity in distribution at the cross sections investigated and that, in the subsonic portion of the mixing zone, the velocity distribution fitted the theoretical distribution for incompressible flow. It was found that the rates of spread of the mixing zone both into the jet and into the ambient air were less than those of subsonic jets.

Dynamics of the transition zone in coastal zone color scanner-sensed ocean color in the North Pacific during oceanographic spring

NASA Technical Reports Server (NTRS)

Glover, David M.; Wroblewski, J. S.; Mcclain, Charles R.

1994-01-01

A transition zone in phytoplankton concentration running across the North Pacific basin at 30 deg to 40 deg north latitude corresponds to a basin-wide front in surface chlorophyll observed in a composite of coastal zone color scanner (CZCS) images for May, June, and July 1979-1986. This transition zone with low chlorophyll to the south and higher chlorophyll to the north can be simulated by a simple model of the concentration of phytoplankton, zooplankton, and dissolved nutrient (nitrate) in the surface mixed layer of the ocean applied to the North Pacific basin for the climatological conditions during oceanographic springtime (May, June, and July). The model is initialized with a 1 deg x 1 deg gridded estimate of wintertime (February, March, and April) mixed layer nitrate concentrations calculated from an extensive nutrient database and a similarly gridded mixed layer depth data set. Comparison of model predictions with CZCS data provides a means of evaluating the dynamics of the transition zone. We conclude that in the North Pacific, away from major boundary currents and coastal upwelling zones, wintertime vertical mixing determines the total nutrient available to the plankton ecosystem in the spring. The transition zone seen in basin-scale CZCS images is a reflection of the geographic variation in the wintertime mixed layer depth and the nitracline, leading to a latitudinal gradient in phytoplankton chlorophyll.

Field-testing competing runoff source and hydrochemical conceptualisations

NASA Astrophysics Data System (ADS)

Western, A. W.; Saffarpour, S.; Adams, R.; Costelloe, J. F.; McDonnell, J.

2014-12-01

There are competing conceptualisations of heterogeneity in catchment systems. It is often convenient to divide catchments into zones, for example the soil profile, groundwater aquifers (saturated zone), riparian zones, etc. We also often divide flow sources into distinct categories such as surface runoff, interflow and baseflow, implying a few distinct stores of water. In tracer hydrology we typically assume water from such zones has distinct and invariant chemistry that is used to infer the runoff source mixture through conservative mixing model techniques such as End-Member Mixing Analysis (EMMA). An alternative conceptualisation is that catchments consist of a large number of stores with varying residence times. In this case individual stores contribute a variable proportion of flow and may have a temporally varying composition due to processes such as evapo-concentration. Hence they have a variable influence on the hydrochemistry of runoff. In this presentation, examples from two field studies in southern Australia will be presented that examine the relationships between hydrologic and hydrochemical conceptualisations and the relative variation within and between different hydrologic zones. The implications for water quality behaviour will be examined and the additional behavioural complexities associated with interactions between runoff pathways for non-conservative chemical species will be discussed.

Method for continuous synthesis of metal oxide powders

DOEpatents

Berry, David A.; Haynes, Daniel J.; Shekhawat, Dushyant; Smith, Mark W.

2015-09-08

A method for the rapid and continuous production of crystalline mixed-metal oxides from a precursor solution comprised of a polymerizing agent, chelated metal ions, and a solvent. The method discharges solution droplets of less than 500 .mu.m diameter using an atomizing or spray-type process into a reactor having multiple temperature zones. Rapid evaporation occurs in a first zone, followed by mixed-metal organic foam formation in a second zone, followed by amorphous and partially crystalline oxide precursor formation in a third zone, followed by formation of the substantially crystalline mixed-metal oxide in a fourth zone. The method operates in a continuous rather than batch manner and the use of small droplets as the starting material for the temperature-based process allows relatively high temperature processing. In a particular embodiment, the first zone operates at 100-300.degree. C., the second zone operates at 300-700.degree. C., and the third operates at 700-1000.degree. C., and fourth zone operates at at least 700.degree. C. The resulting crystalline mixed-metal oxides display a high degree of crystallinity and sphericity with typical diameters on the order of 50 .mu.m or less.

"The Woods Is a More Free Space for Children to Be Creative; Their Imagination Kind of Sparks out There": Exploring Young Children's Cognitive Play Opportunities in Natural, Manufactured and Mixed Outdoor Preschool Zones

ERIC Educational Resources Information Center

Zamani, Zahra

2016-01-01

Outdoor preschools are critical for children's play and development. Integrating observational and interview methods, this study examined four-to-five-year-old children's cognitive play experiences in an outdoor preschool with natural, mixed and manufactured zones. The observational results indicated that the natural and mixed zones offered a…

Shock induced Richtmyer-Meshkov instability in the presence of a wall boundary layer

NASA Astrophysics Data System (ADS)

Jourdan, G.; Billiotte, M.; Houas, L.

1996-06-01

An experimental investigation on gaseous mixing zones originated from the Richtmyer-Meshkov instability has been undertaken in a square cross section shock tube. Mass concentration fields, of one of the two mixing constituents, have been determined within the mixing zone when the shock wave passes from the heavy gas to the light one, from one gas to an other of close density, and from the light gas to the heavy one. Results have been obtained before and after the coming back of the reflected shock wave. The diagnostic method is based on the infrared absorption of one of the two constituents of the mixing zone. It is shown that the mixing zone is strongly deformed by the wall boundary layer. The consequence is the presence of strong gradients of concentration in the direction perpendicular to the shock wave propagation. Finally, it is pointed out that the mixing goes more homogeneous when the Atwood number tends to zero.

EXTRACTION OF URANIUM

DOEpatents

Schmieding, E.G.; Ruehle, A.E.

1961-04-11

A method is given for extracting metal values from an aqueous feed wherein the aqueous feed is passed countercurrent to an organic extractant through a plurality of decanting zones and a portion of the mixture contained in each decanting zone is recycled through a mixing zone associated therewith. The improvement consists of passing more solvent from the top of one decanting zone to the bottom of the preceding decanting zone than can rise to the top thereof and recycling that portion of the solvent that does not rise to the top back to the first named decanting zone through its associated mixing zone.

Modelling the vertical distribution of Prochlorococcus and Synechococcus in the North Pacific Subtropical Ocean.

PubMed

Rabouille, Sophie; Edwards, Christopher A; Zehr, Jonathan P

2007-10-01

A simple model was developed to examine the vertical distribution of Prochlorococcus and Synechococcus ecotypes in the water column, based on their adaptation to light intensity. Model simulations were compared with a 14-year time series of Prochlorococcus and Synechococcus cell abundances at Station ALOHA in the North Pacific Subtropical Gyre. Data were analysed to examine spatial and temporal patterns in abundances and their ranges of variability in the euphotic zone, the surface mixed layer and the layer in the euphotic zone but below the base of the mixed layer. Model simulations show that the apparent occupation of the whole euphotic zone by a genus can be the result of a co-occurrence of different ecotypes that segregate vertically. The segregation of ecotypes can result simply from differences in light response. A sensitivity analysis of the model, performed on the parameter alpha (initial slope of the light-response curve) and the DIN concentration in the upper water column, demonstrates that the model successfully reproduces the observed range of vertical distributions. Results support the idea that intermittent mixing events may have important ecological and geochemical impacts on the phytoplankton community at Station ALOHA.

Groundwater mixing at fracture intersections triggers massive iron-rich microbial mats

NASA Astrophysics Data System (ADS)

Bochet, O.; Le Borgne, T.; Bethencourt, L.; Aquilina, L.; Dufresne, A.; Pédrot, M.; Farasin, J.; Abbott, B. W.; Labasque, T.; Chatton, E.; Lavenant, N.; Petton, C.

2017-12-01

While most freshwater on Earth resides and flows in groundwater systems, these deep subsurface environments are often assumed to have little biogeochemical activity compared to surface environments. Here we report a massive microbial mat of iron-oxidizing bacteria, flourishing 60 meters below the surface, far below the mixing zone where most microbial activity is believed to occur. The abundance of microtubular structures in the mat hinted at the prevalence of of Leptothrix ochracea, but metagenomic analysis revealed a diverse consortium of iron-oxidizing bacteria dominated by unknown members of the Gallionellaceae family. This deep biogeochemical hot spot formed at the intersection of bedrock fractures, which maintain redox gradients by mixing water with different residence times and chemical compositions. Using measured fracture properties and hydrological conditions we developed a quantitative model to simulate the reactive zone where such deep hot spots could occur. While seasonal fluctuations are generally thought to decrease with depth, we found that meter-scale changes in water table level moved the depth of the reactive zone hundreds of meters because the microaerophilic threshold for ironoxidizers is highly sensitive to changes in mixing rates at fracture intersections. These results demonstrate that dynamic microbial communities can be sustained deep below the surface in bedrock fractures. Given the ubiquity of fractures at multiple scales in Earth's subsurface, such deep hot spots may strongly influence global biogeochemical cycles.

Fault architecture and deformation processes within poorly lithified rift sediments, Central Greece

NASA Astrophysics Data System (ADS)

Loveless, Sian; Bense, Victor; Turner, Jenni

2011-11-01

Deformation mechanisms and resultant fault architecture are primary controls on the permeability of faults in poorly lithified sediments. We characterise fault architecture using outcrop studies, hand samples, thin sections and grain-size data from a minor (1-10 m displacement) normal-fault array exposed within Gulf of Corinth rift sediments, Central Greece. These faults are dominated by mixed zones with poorly developed fault cores and damage zones. In poorly lithified sediment deformation is distributed across the mixed zone as beds are entrained and smeared. We find particulate flow aided by limited distributed cataclasis to be the primary deformation mechanism. Deformation may be localised in more competent sediments. Stratigraphic variations in sediment competency, and the subsequent alternating distributed and localised strain causes complexities within the mixed zone such as undeformed blocks or lenses of cohesive sediment, or asperities at the mixed zone/protolith boundary. Fault tip bifurcation and asperity removal are important processes in the evolution of these fault zones. Our results indicate that fault zone architecture and thus permeability is controlled by a range of factors including lithology, stratigraphy, cementation history and fault evolution, and that minor faults in poorly lithified sediment may significantly impact subsurface fluid flow.

Petrologic constraints on rift-zone processes - Results from episode 1 of the Puu Oo eruption of Kilauea volcano, Hawaii

USGS Publications Warehouse

Garcia, M.O.; Ho, R.A.; Rhodes, J.M.; Wolfe, E.W.

1989-01-01

The Puu Oo eruption in the middle of Kilauea volcano's east rift zone provides an excellent opportunity to utilize petrologic constraints to interpret rift-zone processes. Emplacement of a dike began 24 hours before the start of the eruption on 3 January 1983. Seismic and geodetic evidence indicates that the dike collided with a magma body in the rift zone. Most of the lava produced during the initial episode of the Puu Oo eruption is of hybrid composition, with petrographic and geochemical evidence of mixing magmas of highly evllved and more mafic compositions. Some olivine and plagioclase grains in the hybrid lavas show reverse zoning. Whole-rock compositional variations are linear even for normally compatible elements like Ni and Cr. Leastsquares mixing calculations yield good residuals for major and trace element analyses for magma mixing. Crystal fractionation calculations yield unsatisfactory residuals. The highly evolved magma is similar in composition to the lava from the 1977 eruption and, at one point, vents for these two eruptions are only 200 m apart. Possibly both the 1977 lava and the highly evolved component of the episode 1 Puu Oo lava were derived from a common body of rift-zone-stored magma. The more mafic mixing component may be represented by the most mafic lava from the January 1983 eruption; it shows no evidence of magma mixing. The dike that was intruded just prior to the start of the Puu Oo eruption may have acted as a hydraulic plunger causing mixing of the two rift-zone-stored magmas. ?? 1989 Springer-Verlag.

On the mechanism of the ring zone effect obtained with the mixed haemadsorption technique

PubMed Central

Jonsson, J.; Fagraeus, Astrid

1969-01-01

A ring zone effect noted with the radial diffusion disc test modification of the mixed haemadsorption technique has been studied using human anti-thyroid sera reacting with thyroid monolayer cultures. Results are presented which suggest that the `empty' centre of the ring zones is due to an excess of attached antibody. Sera giving the ring zone effect contain a larger number of antibody specificities than those producing filled zones. The appearance of ring zones is favoured by a low density of antigens on the culture. These findings and a number of synergistic effects produced by mixing ring and filled zone reactions are compatible with the hypothesis that the ring zone is produced when several antibodies of different specificities react with restricted antigenic areas carrying densely located clusters of antigenic determinants representing the different specificities contained in the ring zone sera. The crowding of antibodies on the clusters in the centre of the ring zones creates a steric hindrance for the indicator cells so that they are not firmly attached in this area. The antibody zone is therefore indicated as a peripheral haemadsorption ring. ImagesFIG. 1FIG. 2FIG. 4FIG. 6FIG. 7FIG. 9 PMID:5307718

Infrared imaging results of an excited planar jet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrington, R.B.

1991-12-01

Planar jets are used for many applications including heating, cooling, and ventilation. Generally such a jet is designed to provide good mixing within an enclosure. In building applications, the jet provides both thermal comfort and adequate indoor air quality. Increased mixing rates may lead to lower short-circuiting of conditioned air, elimination of dead zones within the occupied zone, reduced energy costs, increased occupant comfort, and higher indoor air quality. This paper discusses using an infrared imaging system to show the effect of excitation of a jet on the spread angle and on the jet mixing efficiency. Infrared imaging captures amore » large number of data points in real time (over 50,000 data points per image) providing significant advantages over single-point measurements. We used a screen mesh with a time constant of approximately 0.3 seconds as a target for the infrared camera to detect temperature variations in the jet. The infrared images show increased jet spread due to excitation of the jet. Digital data reduction and analysis show change in jet isotherms and quantify the increased mixing caused by excitation. 17 refs., 20 figs.« less

Refracted arrival waves in a zone of silence from a finite thickness mixing layer.

PubMed

Suzuki, Takao; Lele, Sanjiva K

2002-02-01

Refracted arrival waves which propagate in the zone of silence of a finite thickness mixing layer are analyzed using geometrical acoustics in two dimensions. Here, two simplifying assumptions are made: (i) the mean flow field is transversely sheared, and (ii) the mean velocity and temperature profiles approach the free-stream conditions exponentially. Under these assumptions, ray trajectories are analytically solved, and a formula for acoustic pressure amplitude in the far field is derived in the high-frequency limit. This formula is compared with the existing theory based on a vortex sheet corresponding to the low-frequency limit. The analysis covers the dependence on the Mach number as well as on the temperature ratio. The results show that both limits have some qualitative similarities, but the amplitude in the zone of silence at high frequencies is proportional to omega(-1/2), while that at low frequencies is proportional to omega(-3/2), omega being the angular frequency of the source.

Use of eddy current mixes to solve a weld examination application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, R.C.; LaBoissonniere, A.

1995-12-31

The augmentation of typical nondestructive (i.e., ultrasound) weld inspection techniques by the use of eddy current tools may significantly enhance the quality and reliability of weld inspections. One recent example is the development of an eddy current technique for use in the examination of BWR core shroud welds, where multi-frequency mixes are used to eliminate signals coming from the weld material so that the examination of the heat affected zone is enhanced. An analysis tool most commonly associated with ultrasound examinations, the C-Scan based on gated information, may be implemented with eddy current data to enhance analysis.

Process for blending coal with water immiscible liquid

DOEpatents

Heavin, Leonard J.; King, Edward E.; Milliron, Dennis L.

1982-10-26

A continuous process for blending coal with a water immiscible liquid produces a uniform, pumpable slurry. Pulverized raw feed coal and preferably a coal derived, water immiscible liquid are continuously fed to a blending zone (12 and 18) in which coal particles and liquid are intimately admixed and advanced in substantially plug flow to form a first slurry. The first slurry is withdrawn from the blending zone (12 and 18) and fed to a mixing zone (24) where it is mixed with a hot slurry to form the pumpable slurry. A portion of the pumpable slurry is continuously recycled to the blending zone (12 and 18) for mixing with the feed coal.

40 CFR Appendix E to Part 63 - Monitoring Procedure for Nonthoroughly Mixed Open Biological Treatment Systems at Kraft Pulp...

Code of Federal Regulations, 2012 CFR

2012-07-01

.... II. Definitions Biological treatment unit = wastewater treatment unit designed and operated to... last zone in the series and ending with the first zone. B. Data Collection Requirements This method is based upon modeling the nonthoroughly mixed open biological treatment unit as a series of well-mixed...

Optimization of Orifice Geometry for Cross-Flow Mixing in a Cylindrical Duct

NASA Technical Reports Server (NTRS)

Kroll, J. T.; Sowa, W. A.; Samuelsen, G. S.

1996-01-01

Mixing of gaseous jets in a cross-flow has significant applications in engineering, one example of which is the dilution zone of a gas turbine combustor. Despite years of study, the design of the jet injection in combustors is largely based on practical experience. The emergence of NO(x) regulations for stationary gas turbines and the anticipation of aero-engine regulations requires an improved understanding of jet mixing as new combustor concepts are introduced. For example, the success of the staged combustor to reduce the emission of NO(x) is almost entirely dependent upon the rapid and complete dilution of the rich zone products within the mixing section. It is these mixing challenges to which the present study is directed. A series of experiments was undertaken to delineate the optimal mixer orifice geometry. A cross-flow to core-flow momentum-flux ratio of 40 and a mass flow ratio of 2.5 were selected as representative of a conventional design. An experimental test matrix was designed around three variables: the number of orifices, the orifice length-to- width ratio, and the orifice angle. A regression analysis was performed on the data to arrive at an interpolating equation that predicted the mixing performance of orifice geometry combinations within the range of the test matrix parameters. Results indicate that the best mixing orifice geometry tested involves eight orifices with a long-to-short side aspect ratio of 3.5 at a twenty-three degree inclination from the center-line of the mixing section.

Appendix D: Use of wave scenarios to assess potential submerged oil mat (SOM) formation along the coast of Florida and Alabama

USGS Publications Warehouse

Dalyander, P. Soupy; Long, Joseph W.; Plant, Nathaniel G.; Thompson, David M.

2013-01-01

During the Deepwater Horizon oil spill, oil in the surf zone mixed with sediment in the surf zone to form heavier-than-water sediment oil agglomerates of various size, ranging from small (cm-scale) pieces (surface residual balls, SRBs) to large mats (100-m scale, surface residue mats, SR mats). Once SR mats formed in the nearshore or in the intertidal zone, they may have become buried by sand moving onshore or alongshore. To assist in locating possible sites of buried oil, wave scenarios previously developed by the U.S. Geological Survey (USGS) were used to determine the depths at which surface oil had the potential to mix with suspended sediment. For sediment to mix with floating oil and form an agglomerate of sufficient density to sink to the seafloor, either the water must be very shallow (e.g., within the swash zone) or sediment must be suspended to the water surface in sufficient concentrations to create a denser-than-sea water agglomerate. The focus of this study is to analyze suspended sediment mixing with surface oil in depths beyond the swash zone, in order to define the seaward limit of mat formation. A theoretical investigation of sediment dynamics in the nearshore zone revealed that non-breaking waves do not suspend enough sediment to the surface to form sinking sand/oil agglomerates. For this study, it was assumed that the cross-shore distribution of potential agglomerate formation is associated with the primary breaker line, and the presence of plunging breakers, over the time frame of oiling. The potential locations of submerged oil mats (SOMs) are sites where (1) possible agglomerate formation occurred, where (2) sediment accreted post-oiling and buried the SOM, and where (3) the bathymetry has not subsequently eroded to re-expose any mat that may have formed at that site. To facilitate identification of these locations, the range of water level variation over the time frame of oiling was also prescribed, which combined with the wave-breaking depth analysis and pre-oiling bathymetry would identify the potential geographic locations of SOMs.

Regulation of eutrophication susceptibility in oligohaline zones of a northern Gulf of Mexico estuary, Mobile Bay, Alabama

EPA Science Inventory

Variability in estuarine eutrophication susceptibility to nutrinets was examined in a comparative empirical analysis of 7 oligohaline tidal river regions. Eutrophication response, in terms of phytoplankton biomass (chlorophylla), was related to estuarine mixing times scales and ...

A New Mixing Diagnostic and Gulf Oil Spill Movement

NASA Astrophysics Data System (ADS)

Mezić, Igor; Loire, S.; Fonoberov, Vladimir A.; Hogan, P.

2010-10-01

Chaotic advection has served as the paradigm for mixing in fluid flows with simple time dependence. Its skeletal structure is based on analysis of invariant attracting and repelling manifolds in fluid flows. Here we develop a finite-time theory for two-dimensional incompressible fluid flows with arbitrary time dependence and introduce a new mixing diagnostic based on it. Besides stretching events around attracting and repelling manifolds, this allows us to detect hyperbolic mixing zones. We used the new diagnostic to forecast the spatial location and timing of oil washing ashore in Plaquemines Parish and Grand Isle, Louisiana, and Pensacola, Florida, in May 2010 and the flow of oil toward Panama City Beach, Florida, in June 2010.

Impacts of blending on dilution of negatively buoyant brine discharge in a shallow tidal sea.

PubMed

Kämpf, Jochen

2009-07-01

A fine-resolution three-dimensional hydrodynamic model is applied to study the dilution of desalination brine discharged into a tidal sea. Based on given inflow rate and salinity excess of discharge brine, this study explores variations in mid-field dilutions when other low-salinity wastewater is added to the discharge. Findings reveal that this blending leads to a decrease in dilution in the mixing zone and therefore to higher levels of pollutants in this zone, while, on the other hand, the mixing zone occupies a smaller area. The reason is that the discharge of brine creates a density-driven flow that operates to partially remove effluent from the discharge location. This removal is less efficient for the decrease in density excess of the discharge. Hence, in an ambient sea of moderate mixing, blending can be expected to increase the risk of marine pollution in the mixing zone.

Apparatus and method for continuous production of materials

DOEpatents

Chang, Chih-hung; Jin, Hyungdae

2014-08-12

Embodiments of a continuous-flow injection reactor and a method for continuous material synthesis are disclosed. The reactor includes a mixing zone unit and a residence time unit removably coupled to the mixing zone unit. The mixing zone unit includes at least one top inlet, a side inlet, and a bottom outlet. An injection tube, or plurality of injection tubes, is inserted through the top inlet and extends past the side inlet while terminating above the bottom outlet. A first reactant solution flows in through the side inlet, and a second reactant solution flows in through the injection tube(s). With reference to nanoparticle synthesis, the reactant solutions combine in a mixing zone and form nucleated nanoparticles. The nucleated nanoparticles flow through the residence time unit. The residence time unit may be a single conduit, or it may include an outer housing and a plurality of inner tubes within the outer housing.

Lidar measurements of the atmospheric entrainment zone and the potential temperature jump across the top of the mixed layer

NASA Technical Reports Server (NTRS)

Boers, R.; Eloranta, E. W.

1986-01-01

Lidar data of the atmospheric entrainment zone from six days of clear air convection obtained in central Illinois during July 1979 are presented. A new method to measure the potential temperature jump across the entrainment zone based on only one temperature sounding and continuous lidar measurements of the mixed layer height is developed. An almost linear dependence is found between the normalized entrainment rate and the normalized thickness of the entrainment zone.

Magma mixing in the 1100 AD Montaña Reventada composite lava flow, Tenerife, Canary Islands: interaction between rift zone and central volcano plumbing systems

NASA Astrophysics Data System (ADS)

Wiesmaier, S.; Deegan, F. M.; Troll, V. R.; Carracedo, J. C.; Chadwick, J. P.; Chew, D. M.

2011-09-01

Zoned eruption deposits commonly show a lower felsic and an upper mafic member, thought to reflect eruption from large, stratified magma chambers. In contrast, the Montaña Reventada composite flow (Tenerife) consists of a lower basanite and a much thicker upper phonolite. A sharp interface separates basanite and phonolite, and chilled margins at this contact indicate the basanite was still hot upon emplacement of the phonolite, i.e. the two magmas erupted in quick succession. Four types of mafic to intermediate inclusions are found in the phonolite. Inclusion textures comprise foamy quenched ones, others with chilled margins and yet others that are physically mingled, reflecting progressive mixing with a decreasing temperature contrast between the end-members. Analysis of basanite, phonolite and inclusions for majors, traces and Sr, Nd and Pb isotopes show the inclusions to be derived from binary mixing of basanite and phonolite end-members in ratios of 2:1 to 4:1. Although, basanite and phonolite magmas were in direct contact, contrasting 206Pb/204Pb ratios show that they are genetically distinct (19.7193(21)-19.7418(31) vs. 19.7671(18)-19.7807(23), respectively). We argue that the Montaña Reventada basanite and phonolite first met just prior to eruption and had limited interaction time only. Montaña Reventada erupted from the transition zone between two plumbing systems, the phonolitic Teide-Pico Viejo complex and the basanitic Northwest rift zone. A rift zone basanite dyke most likely intersected the previously emplaced phonolite magma chamber. This led to eruption of geochemically and texturally unaffected basanite, with the inclusion-rich phonolite subsequently following into the established conduit.

Landscape-scale food webs of fish nursery habitat along a river-coast mixing zone

EPA Science Inventory

We used carbon and nitrogen stable isotope analysis to study connections between allochthonous energy use and ecological connectivity of fish larvae in a complex coastal mosaic. We quantified fish larvae support by autochthonous and allochthonous material in three coastal river-w...

Rapid gas hydrate formation process

DOEpatents

Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

2013-01-15

The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

Litho-kinematic facies model for large landslide deposits in arid settings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yarnold, J.C.; Lombard, J.P.

1989-04-01

Reconnaissance field studies of six large landslide deposits in the S. Basin and Range suggest that a set of characteristic features is common to the deposits of large landslides in an arid setting. These include a coarse boulder cap, an upper massive zone, a lower disrupted zone, and a mixed zone overlying disturbed substrate. The upper massive zone is dominated by crackel breccia. This grades downward into a lower disrupted zone composed of a more matrix-rich breccia that is internally sheared, intruded by clastic dikes, and often contains a cataclasite layer at its base. An underlying discontinuous mixed zone ismore » composed of material from the overlying breccia mixed with material entrained from the underlying substrate. Bedding in the substrate sometimes displays folding and contortion that die out downward. The authors work suggests a spatial zonation of these characteristic features within many landslide deposits. In general, clastic dikes, the basal cataclasite, and folding in the substrate are observed mainly in distal parts of landslides. In most cases, total thickness, thickness of the basal disturbed and mixed zones, and the degree of internal shearing increase distally, whereas maximum clast size commonly decreases distally. Zonation of these features is interpreted to result from kinematics of emplacement that cause generally increased deformation in the distal regions of the landslide.« less

CORMIX1: AN EXPERT SYSTEM FOR MIXING ZONE ANALYSIS OF TOXIC AND CONVENTIONAL, SINGLE PORT AQUATIC DISCHARGES

EPA Science Inventory

An expert system, CORMIX1, was developed to predict the dilution and trajectory of a single buoyant discharge into an unstratified aquatic environment with and without crossflow. The system uses knowledge and inference rules obtained from hydrodynamic experts to classify and pred...

Quantifying urban river-aquifer fluid exchange processes: a multi-scale problem.

PubMed

Ellis, Paul A; Mackay, Rae; Rivett, Michael O

2007-04-01

Groundwater-river exchanges in an urban setting have been investigated through long term field monitoring and detailed modelling of a 7 km reach of the Tame river as it traverses the unconfined Triassic Sandstone aquifer that lies beneath the City of Birmingham, UK. Field investigations and numerical modelling have been completed at a range of spatial and temporal scales from the metre to the kilometre scale and from event (hourly) to multi-annual time scales. The objective has been to quantify the spatial and temporal flow distributions governing mixing processes at the aquifer-river interface that can affect the chemical activity in the hyporheic zone of this urbanised river. The hyporheic zone is defined to be the zone of physical mixing of river and aquifer water. The results highlight the multi-scale controls that govern the fluid exchange distributions that influence the thickness of the mixing zone between urban rivers and groundwater and the patterns of groundwater flow through the bed of the river. The morphologies of the urban river bed and the adjacent river bank sediments are found to be particularly influential in developing the mixing zone at the interface between river and groundwater. Pressure transients in the river are also found to exert an influence on velocity distribution in the bed material. Areas of significant mixing do not appear to be related to the areas of greatest groundwater discharge and therefore this relationship requires further investigation to quantify the actual remedial capacity of the physical hyporheic zone.

DIVERSE MODELS FOR SOLVING CONTRASTING OUTFALL PROBLEMS

EPA Science Inventory

Mixing zone initial dilution and far-field models are useful for assuring that water quality criteria will be met when specific outfall discharge criteria are applied. Presented here is a selective review of mixing zone initial dilution models and relatively simple far-field tran...

VISUAL PLUMES MIXING ZONE MODELING SOFTWARE

EPA Science Inventory

The U.S. Environmental Protection Agency has a long history of both supporting plume model development and providing mixing zone modeling software. The Visual Plumes model is the most recent addition to the suite of public-domain models available through the EPA-Athens Center f...

Groundwater–surface water mixing shifts ecological assembly processes and stimulates organic carbon turnover

PubMed Central

Stegen, James C.; Fredrickson, James K.; Wilkins, Michael J.; Konopka, Allan E.; Nelson, William C.; Arntzen, Evan V.; Chrisler, William B.; Chu, Rosalie K.; Danczak, Robert E.; Fansler, Sarah J.; Kennedy, David W.; Resch, Charles T.; Tfaily, Malak

2016-01-01

Environmental transitions often result in resource mixtures that overcome limitations to microbial metabolism, resulting in biogeochemical hotspots and moments. Riverine systems, where groundwater mixes with surface water (the hyporheic zone), are spatially complex and temporally dynamic, making development of predictive models challenging. Spatial and temporal variations in hyporheic zone microbial communities are a key, but understudied, component of riverine biogeochemical function. Here, to investigate the coupling among groundwater–surface water mixing, microbial communities and biogeochemistry, we apply ecological theory, aqueous biogeochemistry, DNA sequencing and ultra-high-resolution organic carbon profiling to field samples collected across times and locations representing a broad range of mixing conditions. Our results indicate that groundwater–surface water mixing in the hyporheic zone stimulates heterotrophic respiration, alters organic carbon composition, causes ecological processes to shift from stochastic to deterministic and is associated with elevated abundances of microbial taxa that may degrade a broad suite of organic compounds. PMID:27052662

Groundwater-surface water mixing shifts ecological assembly processes and stimulates organic carbon turnover.

PubMed

Stegen, James C; Fredrickson, James K; Wilkins, Michael J; Konopka, Allan E; Nelson, William C; Arntzen, Evan V; Chrisler, William B; Chu, Rosalie K; Danczak, Robert E; Fansler, Sarah J; Kennedy, David W; Resch, Charles T; Tfaily, Malak

2016-04-07

Environmental transitions often result in resource mixtures that overcome limitations to microbial metabolism, resulting in biogeochemical hotspots and moments. Riverine systems, where groundwater mixes with surface water (the hyporheic zone), are spatially complex and temporally dynamic, making development of predictive models challenging. Spatial and temporal variations in hyporheic zone microbial communities are a key, but understudied, component of riverine biogeochemical function. Here, to investigate the coupling among groundwater-surface water mixing, microbial communities and biogeochemistry, we apply ecological theory, aqueous biogeochemistry, DNA sequencing and ultra-high-resolution organic carbon profiling to field samples collected across times and locations representing a broad range of mixing conditions. Our results indicate that groundwater-surface water mixing in the hyporheic zone stimulates heterotrophic respiration, alters organic carbon composition, causes ecological processes to shift from stochastic to deterministic and is associated with elevated abundances of microbial taxa that may degrade a broad suite of organic compounds.

Magma hybridization in the Western Tatra Mts. granitoid intrusion (S-Poland, Western Carpathians).

PubMed

Burda, Jolanta; Gawęda, Aleksandra; Klötzli, Urs

In the Variscan Western Tatra granites hybridization phenomena such as mixing and mingling can be observed at the contact of mafic precursors of dioritic composition and more felsic granitic host rocks. The textural evidence of hybridization include: plagioclase-K-feldspar-sphene ocelli, hornblende- and biotite-rimmed quartz ocelli, plagioclase with Ca-rich spike zonation, inversely zoned K-feldspar crystals, mafic clots, poikilitic plagioclase and quartz crystals, mixed apatite morphologies, zoned K-feldspar phenocrysts. The apparent pressure range of the magma hybridization event was calculated at 6.1 kbar to 4.6 kbar, while the temperature, calculated by independent methods, is in the range of 810°C-770°C. U-Pb age data of the hybrid rocks were obtained by in-situ LA-MC-ICP-MS analysis of zircon. The oscillatory zoned zircon crystals yield a concordia age of 368 ± 8 Ma (MSWD = 1.1), interpreted as the age of magma hybridization and timing of formation of the magmatic precursors. It is the oldest Variscan magmatic event in that part of the Tatra Mountains.

Mixed stock analysis of Lake Michigan's Lake Whitefish Coregonus clupeaformis commercial fishery

USGS Publications Warehouse

Andvik, Ryan; Sloss, Brian L.; VanDeHey, Justin A.; Claramunt, Randall M.; Hansen, Scott P.; Isermann, Daniel A.

2016-01-01

Lake whitefish (Coregonus clupeaformis) support the primary commercial fishery in Lake Michigan. Discrete genetic stocks of lake whitefish have been identified and tagging data suggest stocks are mixed throughout much of the year. Our objectives were to determine if (1) differential stock harvest occurs in the commercial catch, (2) spatial differences in genetic composition of harvested fish were present, and (3) seasonal differences were present in the harvest by commercial fisheries that operate in management zones WI-2 and WFM-01 (Green Bay, Lake Michigan). Mixed stock analysis was conducted on 17 commercial harvest samples (n = 78–145/sample) collected from various ports lake-wide during 2009–2010. Results showed significant mixing with variability in stock composition across most samples. Samples consisted of two to four genetic stocks each accounting for ≥ 10% the catch. In 10 of 17 samples, the stock contributing the largest proportion made up < 60% of the harvest. In general, seasonal and annual differences existed in the proportional stock contribution at a single capture location. Samples from Wisconsin's primary commercial fishing management zone (WI-2) were composed predominately of fish from the Big Bay de Noc (Michigan) stock as opposed to the geographically proximate, North–Moonlight Bay (Wisconsin) stock. These findings have implications for management and allocation of fish to various quotas. Specifically, geographic location of harvest, the current means of allocating harvest quotas, is not the best predictor of genetic stock harvest.

Analysis of passenger-car crash injury severity in different work zone configurations.

PubMed

Osman, Mohamed; Paleti, Rajesh; Mishra, Sabyasachee

2018-02-01

Work zone safety remains a priority to the Federal Highway Administration, State Highway Departments, highway engineers, and the traveling public. Work zones create a hospitable environment for crashes; an issue that gained tremendous share of attention in recent years. Therefore, every effort should be sought out to reduce the injury severity of crashes in work zones. In this paper we attempt to investigate factors contributing to the injury severity of passenger-car crashes in different work zone configurations. Considering the discrete ordinal nature of injury severity categories, a Mixed Generalized Ordered Response Probit (MGORP) modeling framework was developed. The model estimation was undertaken by compiling a database consisting of 10 years of crashes that involved at least one passenger car, and occurred in a work zone. Revealing the underlying factors contributing to injury severity levels for different work zone configurations will allow for distinguishing mitigation methods for higher severity outcomes that best suit each of the depicted work zone layouts. This can be accomplished through the implementation of specific safety measures based on the specific configuration of a work zone as a potential crash location. Elasticity analysis suggests that partial control of access, roadways classified as rural, crashes during evening times, crashes during weekends, and curved roadways are key factors that increase the likelihood of severe outcomes. Also, the effects of several covariates were found to vary across the different work zone configurations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mixing of ultrasonic Lamb waves in thin plates with quadratic nonlinearity.

PubMed

Li, Feilong; Zhao, Youxuan; Cao, Peng; Hu, Ning

2018-07-01

This paper investigates the propagation of Lamb waves in thin plates with quadratic nonlinearity by one-way mixing method using numerical simulations. It is shown that an A 0 -mode wave can be generated by a pair of S 0 and A 0 mode waves only when mixing condition is satisfied, and mixing wave signals are capable of locating the damage zone. Additionally, it is manifested that the acoustic nonlinear parameter increases linearly with quadratic nonlinearity but monotonously with the size of mixing zone. Furthermore, because of frequency deviation, the waveform of the mixing wave changes significantly from a regular diamond shape to toneburst trains. Copyright © 2018 Elsevier B.V. All rights reserved.

Upper Ocean Response to Hurricanes Katrina and Rita (2005) from Multi-sensor Satellites

NASA Astrophysics Data System (ADS)

Gierach, M. M.; Bulusu, S.

2006-12-01

Analysis of satellite observations and model simulations of the mixed layer provided an opportunity to assess the biological and physical effects of hurricanes Katrina and Rita (2005) in the Gulf of Mexico. Oceanic cyclonic circulation was intensified by the hurricanes' wind field, maximizing upwelling, surface cooling, and deepening the mixed layer. Two areas of maximum surface chlorophyll-a concentration and sea surface cooling were detected with peak intensities ranging from 2-3 mg m-3 and 4-6°C, along the tracks of Katrina and Rita. The temperature of the mixed layer cooled approximately 2°C and the depth of the mixed layer deepened by approximately 33-52 m. The forced deepening of the mixed layer injected nutrients into the euphotic zone, generating phytoplankton blooms 3-5 days after the passage of Katrina and Rita (2005).

Condensation in Supernova Ejecta at High Spatial Resolution

NASA Astrophysics Data System (ADS)

Fedkin, A. V.; Meyer, B. S.; Grossman, L.; Desch, S. J.

2009-03-01

^44Ti-rich TiC condenses before graphite in SN ejecta only if thin sub-layers of the main burning zones mix together; such mixing is also needed to form Fe-olivine. High-T phases change from carbides to oxides along composition gradients within the He/N zone.

Tritium and 36Cl as constraints on fast fracture flow and percolation flux in the unsaturated zone at Yucca Mountain

NASA Astrophysics Data System (ADS)

Guerin, Marianne

2001-10-01

An analysis of tritium and 36Cl data collected at Yucca Mountain, Nevada suggests that fracture flow may occur at high velocities through the thick unsaturated zone. The mechanisms and extent of this "fast flow" in fractures at Yucca Mountain are investigated with data analysis, mixing models and several one-dimensional modeling scenarios. The model results and data analysis provide evidence substantiating the weeps model [Gauthier, J.H., Wilson, M.L., Lauffer, F.C., 1992. Proceedings of the Third Annual International High-level Radioactive Waste Management Conference, vol. 1, Las Vegas, NV. American Nuclear Society, La Grange Park, IL, pp. 891-989] and suggest that fast flow in fractures with minimal fracture-matrix interaction may comprise a substantial proportion of the total infiltration through Yucca Mountain. Mixing calculations suggest that bomb-pulse tritium measurements, in general, represent the tail end of travel times for thermonuclear-test-era (bomb-pulse) infiltration. The data analysis shows that bomb-pulse tritium and 36Cl measurements are correlated with discrete features such as horizontal fractures and areas where lateral flow may occur. The results presented here imply that fast flow in fractures may be ubiquitous at Yucca Mountain, occurring when transient infiltration (storms) generates flow in the connected fracture network.

Tritium and 36Cl as constraints on fast fracture flow and percolation flux in the unsaturated zone at Yucca Mountain.

PubMed

Guerin, M

2001-10-01

An analysis of tritium and 36Cl data collected at Yucca Mountain, Nevada suggests that fracture flow may occur at high velocities through the thick unsaturated zone. The mechanisms and extent of this "fast flow" in fractures at Yucca Mountain are investigated with data analysis, mixing models and several one-dimensional modeling scenarios. The model results and data analysis provide evidence substantiating the weeps model [Gauthier, J.H., Wilson, M.L., Lauffer, F.C., 1992. Proceedings of the Third Annual International High-level Radioactive Waste Management Conference, vol. 1, Las Vegas, NV. American Nuclear Society, La Grange Park, IL, pp. 891-989] and suggest that fast flow in fractures with minimal fracture-matrix interaction may comprise a substantial proportion of the total infiltration through Yucca Mountain. Mixing calculations suggest that bomb-pulse tritium measurements, in general, represent the tail end of travel times for thermonuclear-test-era (bomb-pulse) infiltration. The data analysis shows that bomb-pulse tritium and 36Cl measurements are correlated with discrete features such as horizontal fractures and areas where lateral flow may occur. The results presented here imply that fast flow in fractures may be ubiquitous at Yucca Mountain, occurring when transient infiltration (storms) generates flow in the connected fracture network.

Reproduction allocation and potential mechanism of individual allelopathic rice plants in the presence of competing barnyardgrass.

PubMed

Kong, Chui-Hua; Wang, Ming-Li; Wang, Peng; Ni, Han-Wen; Meng, Xiang-Rui

2013-01-01

In spite of increasing knowledge of allelopathic rice as an efficient component involved in paddy weed management, relatively little is known about its reproduction in response to competing weeds. Reproduction allocation of individual allelopathic rice plants in relation to monoculture and mixed culture with competing barnyardgrass in a paddy field was studied, along with analyses of soil nutrients and microbial communities to understand the potential mechanism. At a 1:1 barnyardgrass and rice mixture proportion identified from a replacement series study, biomass, grain yield and major parameters of individual allelopathic rice plants at the mature stage were increased by competing barnyardgrass. There was no difference in allelopathic rice root-zone soil ammonium N and Olsen P between monoculture and mixed culture. However, mixed culture altered soil microbial biomass C and communities. When mixed with barnyardgrass, allelopathic rice root zone had an 87% increase in soil microbial biomass C. Phospholipid fatty acid (PLFA) profiling indicated that the signature lipid biomarkers of bacteria, actinobacteria and fungi were affected by mixed culture. Principal component analysis clearly identified differences in the composition of PLFA in different soil samples. Allelopathic rice specific changes in soil microbial communities may generate a positive feedback on its own growth and reproduction in the presence of competing barnyardgrass in a given paddy system. Copyright © 2012 Society of Chemical Industry.

Entrainment Zone Characteristics and Entrainment Rates in Cloud-Topped Boundary Layers from DYCOMS-II

DTIC Science & Technology

2012-03-01

water and ozone across the EIL. The scalar variables from this flight (not shown) suggest significant horizontal variation in the free- troposphere ...near the cloud top where mixing occurs between dry free- troposphere air and moist turbulent air. Although the concept of the entrainment zone is...mixing occurs between dry free- troposphere air and moist turbulent air. Although the concept of the entrainment zone is clear, defining the top and

Achieving a Healthy Zoning Policy in Baltimore: Results of a Health Impact Assessment of the TransForm Baltimore Zoning Code Rewrite

PubMed Central

Greiner, Amelia; Fichtenberg, Caroline M.; Feingold, Beth J.; Ellen, Jonathan M.; Jennings, Jacky M.

2013-01-01

Objectives The social determinants of health (SDH) include factors apart from genes and biology that affect population health. Zoning is an urban planning tool that influences neighborhood built environments. We describe the methods and results of a health impact assessment (HIA) of a rezoning effort in Baltimore, Maryland, called TransForm Baltimore. We highlight findings specific to physical activity, violent crime, and obesity. Methods We conducted a multistage HIA of TransForm Baltimore using HIA practice guidelines. Key informant interviews identified focus areas for the quantitative assessment. A literature review and a zoning code analysis evaluated potential impacts on neighborhood factors including physical activity, violent crime, and obesity. We estimated potential impacts in high- and low-poverty neighborhoods. The findings resulted in recommendations to improve the health-promoting potential of TransForm Baltimore. Results Mixed-use and transit-oriented development were key goals of TransForm Baltimore. Health impacts identified by stakeholders included walkability and healthy communities. For Baltimore residents, we estimated that (1) the percentage of people living in districts allowing mixed-use and off-premise alcohol outlets would nearly triple, (2) 18% would live in transit-oriented development zones, and (3) all residents would live in districts with new lighting and landscaping guidelines. Limiting the concentration of off-premise alcohol outlets represented an opportunity to address health promotion. Conclusions Changes to Baltimore's zoning code could improve population health including decreasing violent crime. HIAs are an important platform for applying SDH to public health practice. This HIA specifically linked municipal zoning policy with promoting healthier neighborhoods. PMID:24179284

Multi-Scale Analysis for Characterizing Near-Field Constituent Concentrations in the Context of a Macro-Scale Semi-Lagrangian Numerical Model

NASA Astrophysics Data System (ADS)

Yearsley, J. R.

2017-12-01

The semi-Lagrangian numerical scheme employed by RBM, a model for simulating time-dependent, one-dimensional water quality constituents in advection-dominated rivers, is highly scalable both in time and space. Although the model has been used at length scales of 150 meters and time scales of three hours, the majority of applications have been at length scales of 1/16th degree latitude/longitude (about 5 km) or greater and time scales of one day. Applications of the method at these scales has proven successful for characterizing the impacts of climate change on water temperatures in global rivers and on the vulnerability of thermoelectric power plants to changes in cooling water temperatures in large river systems. However, local effects can be very important in terms of ecosystem impacts, particularly in the case of developing mixing zones for wastewater discharges with pollutant loadings limited by regulations imposed by the Federal Water Pollution Control Act (FWPCA). Mixing zone analyses have usually been decoupled from large-scale watershed influences by developing scenarios that represent critical scenarios for external processes associated with streamflow and weather conditions . By taking advantage of the particle-tracking characteristics of the numerical scheme, RBM can provide results at any point in time within the model domain. We develop a proof of concept for locations in the river network where local impacts such as mixing zones may be important. Simulated results from the semi-Lagrangian numerical scheme are treated as input to a finite difference model of the two-dimensional diffusion equation for water quality constituents such as water temperature or toxic substances. Simulations will provide time-dependent, two-dimensional constituent concentration in the near-field in response to long-term basin-wide processes. These results could provide decision support to water quality managers for evaluating mixing zone characteristics.

Temporally resolved planar measurements of transient phenomena in a partially pre-mixed swirl flame in a gas turbine model combustor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boxx, I.; Stoehr, M.; Meier, W.

This paper presents observations and analysis of the time-dependent behavior of a 10 kW partially pre-mixed, swirl-stabilized methane-air flame exhibiting self-excited thermo-acoustic oscillations. This analysis is based on a series of measurements wherein particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of the OH radical were performed simultaneously at 5 kHz repetition rate over durations of 0.8 s. Chemiluminescence imaging of the OH{sup *} radical was performed separately, also at 5 kHz over 0.8 s acquisition runs. These measurements were of sufficient sampling frequency and duration to extract usable spatial and temporal frequency information on the medium to large-scalemore » flow-field and heat-release characteristics of the flame. This analysis is used to more fully characterize the interaction between the self-excited thermo-acoustic oscillations and the dominant flow-field structure of this flame, a precessing vortex core (PVC) present in the inner recirculation zone. Interpretation of individual measurement sequences yielded insight into various physical phenomena and the underlying mechanisms driving flame dynamics. It is observed for this flame that location of the reaction zone tracks large-scale fluctuations in axial velocity and also conforms to the passage of large-scale vortical structures through the flow-field. Local extinction of the reaction zone in regions of persistently high principal compressive strain is observed. Such extinctions, however, are seen to be self healing and thus do not induce blowout. Indications of auto-ignition in regions of unburned gas near the exit are also observed. Probable auto-ignition events are frequently observed coincident with the centers of large-scale vortical structures, suggesting the phenomenon is linked to the enhanced mixing and longer residence times associated with fluid at the core of the PVC as it moves through the flame. (author)« less

Groundwater–surface water mixing shifts ecological assembly processes and stimulates organic carbon turnover

DOE PAGES

Stegen, James C.; Fredrickson, James K.; Wilkins, Michael J.; ...

2016-04-07

Environmental transition zones are associated with geochemical gradients that overcome energy limitations to microbial metabolism, resulting in biogeochemical hot spots and moments. Riverine systems where groundwater mixes with surface water (the hyporheic zone) are spatially complex and temporally dynamic, making development of predictive models challenging. Spatial and temporal variations in hyporheic zone microbial communities are a key, but understudied, component of riverine biogeochemical function. To investigate the coupling among groundwater-surface water mixing, microbial communities, and biogeochemistry we applied ecological theory, aqueous biogeochemistry, DNA sequencing, and ultra-high resolution organic carbon profiling to field samples collected across times and locations representing amore » broad range of mixing conditions. Mixing of groundwater and surface water resulted in a shift from transport-driven stochastic dynamics to a deterministic microbial structure associated with elevated biogeochemical rates. While the dynamics of the hyporheic make predictive modeling a challenge, we provide new knowledge that can improve the tractability of such models.« less

Experimental and numerical study on particle distribution in a two-zone chamber

NASA Astrophysics Data System (ADS)

Lai, Alvin C. K.; Wang, K.; Chen, F. Z.

Better understanding of aerosol dynamics is an important step for improving personal exposure assessments in indoor environments. Although the limitation of the assumptions in a well-mixed model is well known, there has been very little research reported in the published literature on the discrepancy of exposure assessments between numerical models which take account of gravitational effects and the well-mixed model. A new Eulerian-type drift-flux model has been developed to simulate particle dispersion and personal exposure in a two-zone geometry, which accounts for the drift velocity resulting from gravitational settling and diffusion. To validate the numerical model, a small-scale chamber was fabricated. The airflow characteristics and particle concentrations were measured by a phase Doppler Anemometer. Both simulated airflow and concentration profiles agree well with the experimental results. A strong inhomogeneous concentration was observed experimentally for 10 μm aerosols. The computational model was further applied to study a simple hypothetical, yet more realistic scenario. The aim was to explore different levels of exposure predicted by the new model and the well-mixed model. Aerosols are initially uniformly distributed in one zone and subsequently transported and dispersed to an adjacent zone through an opening. Owing to the significant difference in the rates of transport and dispersion between aerosols and gases, inferred from the results, the well-mixed model tends to overpredict the concentration in the source zone, and under-predict the concentration in the exposed zone. The results are very useful to illustrate that the well-mixed assumption must be applied cautiously for exposure assessments as such an ideal condition may not be applied for coarse particles.

Aerodynamic drag characterization and deposition studies of irregular particles. Part 3: Analysis of flow and temperature field inside the Combustion Deposition Entrained Reactor (CDER)

NASA Astrophysics Data System (ADS)

Celik, I.; Katragadda, S.; Nagarajan, R.

1990-01-01

An experimental and numerical analysis was performed of the temperature and flow field involved in co-axial, confined, non-reacting heated jets in a drop tube reactor. An electrically heated 2-inch (50.8 mm) diameter drop tube reactor was utilized to study the jet characteristics. Profiles of gas temperature, typically in the range of 800 to 1600 K were measured in the mixing zone of the jet with a K-Type thermocouple. Measured temperatures were corrected for conduction, convection, and radiation heat losses. Because of limited access to the mixing zone, characterization of the flow field at high temperatures with laser Doppler or hot wire anemometry were impractical. A computer program which solves the full equations of motion and energy was employed to simulate the temperature and flow fields. The location of the recirculation region, the flow regimes, and the mixing phenomena were studied. The wall heating, laminar and turbulent flow regimes were considered in the simulations. The predictions are in fairly good agreement with the corrected temperature measurements provided that the flow is turbulent. The results of this study demonstrate how a numerical method and measurement can be used together to analyze the flow conditions inside a reactor which has limited access because of very high temperatures.

Habitat Association and Seasonality in a Mosaic and Bimodal Hybrid Zone between Chorthippus brunneus and C. jacobsi (Orthoptera: Acrididae)

PubMed Central

Tatsuta, Haruki; Butlin, Roger K.

2012-01-01

Understanding why some hybrid zones are bimodal and others unimodal can aid in identifying barriers to gene exchange following secondary contact. The hybrid zone between the grasshoppers Chorthippus brunneus and C. jacobsi contains a mix of allopatric parental populations and inter-mingled bimodal and unimodal sympatric populations, and provides an ideal system to examine the roles of local selection and gene flow between populations in maintaining bimodality. However, it is first necessary to confirm, over a larger spatial scale, previously identified associations between population composition and season and habitat. Here we use cline-fitting of one morphological and one song trait along two valley transects, and intervening mountains, to confirm previously identified habitat associations (mountain versus valley) and seasonal changes in population composition. As expected from previous findings of studies on a smaller spatial scale, C. jacobsi dominated mountain habitats and mixed populations dominated valleys, and C. brunneus became more prevalent in August. Controlling for habitat and incorporating into the analysis seasonal changes in cline parameters and the standard errors of parental trait values revealed wider clines than previous studies (best estimates of 6.4 to 24.5 km in our study versus 2.8 to 4.7 km in previous studies) and increased percentage of trait variance explained (52.7% and 61.5% for transects 1 and 2 respectively, versus 17.6%). Revealing such strong and consistent patterns within a complex hybrid zone will allow more focused examination of the causes of variation in bimodality in mixed populations, in particular the roles of local selection versus habitat heterogeneity and gene flow between differentiated populations. PMID:22675485

Mechanisms governing brittle fault mechanics - a multi-scale study from the Permian Khao-Kwang fold-and-thrust belt, Thailand

NASA Astrophysics Data System (ADS)

von Hagke, Christoph; Morley, Chris; Kanitpanyacharoen, Waruntorn

2017-04-01

Despite our qualitative understanding of factors contributing to thrust and detachment weakness such as mineralogy, pore fluid pressure, or efficiency of structure localization, it is difficult to assess the contribution of the individual factors. Here we present multi-scale analysis of a mixed clay / carbonate high displacement (kms of heave) thrust zone, where it is possible to study structures formed within a similar temperature and pressure regime, and thus only varying due to lithological contrasts. We mapped the well-exposed thrust zone in a large quarry at outcrop scale in five separate sections present along a strike-distance of 1 km. The thrust zone shows considerable variations in structural style, as well as localization within different clay and limestone horizons. Zones of low and high strain have been identified. We investigate these changes in macroscopic deformation style using Virtual Polarizing Microscopy, and the combined methods of Broad Ion Beam milling and Scanning Electron Microscopy in addition with XRD analysis. We characterize structural and mineralogical variations in the thrust zone at all scales, from outcrop down to nano-meters. Results show strain localization is heterogeneous, with strong variations along strike. Within the clay package, strain localizes along zones rich in organic matter. Microstructures are complex, and show multiple deformation events, including crack-seal processes and reworking of vein material. Pressure solution is dominant. XRD analysis shows mineralogical differences between zones of high and low strain within the shale-dominated package. However, highest strain does not only occur in the clay units, but partly is accommodated in the surrounding limestone.

Mixing of Pure Air Jets with a Reacting Fuel-Rich Crossflow

NASA Technical Reports Server (NTRS)

Leong, M. Y.; Samuelsen, G. S.; Holdeman, J. D.

1997-01-01

Jets in a crossflow play an integral role in practical combustion systems such as can and annular gas turbine combustors in conventional systems, and the Rich-burn/Quick-mix/Lean-burn (RQL) combustor utilized in stationary applications and proposed for advanced subsonic and supersonic transports. The success of the RQL combustor rests with the performance of the quick-mixing section that bridges the rich and lean zones. The mixing of jet air with a rich crossflow to bring the reaction to completion in the lean zone must be performed rapidly and thoroughly in order to decrease the extent of near-stoichiometric fluid pocket formation. Fluid pockets at near-stoichiometric equivalence ratios are undesirable because the high temperatures attained accelerate pollutant formation kinetics associated with nitric oxide (NO). The present study develops a model experiment designed to reveal the processes that occur when jet air is introduced into hot effluent emanating from a fuel-rich reaction zone.

The sensitivity of primary productivity to intra-seasonal mixed layer variability in the sub-Antarctic Zone of the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Joubert, W. R.; Swart, S.; Tagliabue, A.; Thomalla, S. J.; Monteiro, P. M. S.

2014-03-01

The seasonal cycle of primary productivity is impacted by seasonal and intra-seasonal dynamics of the mixed layer through the changing balance between mixing and buoyancy forcing, which regulates nutrient supply and light availability. Of particular recent interest is the role of synoptic scale events in supplying nutrients, particularly iron, to the euphotic zone in the Sub Antarctic Zone (SAZ), where phytoplankton blooms occur throughout summer. In this study, we present high resolution measurements of net community production (NCP) constrained by ΔO2/Ar ratios, and mixed layer depth (MLD) in the Atlantic SAZ. We found a non-linear relationship between NCP and MLD, with the highest and most variable NCP observed in shallow MLDs (< 45 m). We propose that NCP variability in the SAZ may be driven by alternating states of synoptic-scale deepening of the mixed layer, leading to the entrainment of iron (dFe), followed by restratification, allowing rapid growth in an iron replete, high light environment. Synoptic iron fluxes into the euphotic zone based on water column dFe profiles and high resolution glider MLD data, reveal a potentially significant contribution of "new iron" which could sustain NCP throughout summer. Future process studies will help elaborate these findings further.

Final Project Report, DE-SC0001280, Characterizing the Combined Roles of Iron and Transverse Mixing on Uranium Bioremediation in Groundwater using Microfluidic Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finneran, Kevin; Werth, Charles; Strathmann, Timothy

2015-01-10

In situ bioremediation of U(VI) involves amending groundwater with an appropriate electron donor and limiting nutrients to promote biological reduction to the less soluble and mobile U(IV) oxidation state. Groundwater flow is laminar; mixing is controlled by hydrodynamic dispersion. Recent studies indicate that transverse dispersion along plume margins can limit mixing of the amended electron donor and accepter (such as U(VI) in remediation applications). As a result, microbial growth, and subsequently contaminant reaction, may be limited to these transverse mixing zones during bioremediation. The primary objective of this work was to characterize the combined effects of hydrology, geochemistry, and biologymore » on the (bio)remediation of U(VI). Our underlying hypothesis was that U(VI) reaction in groundwater is controlled by transverse mixing with an electron donor along plume margins, and that iron bioavailability in these zones affects U(VI) reduction kinetics and U(IV) re-oxidation. Our specific objectives were to a) quantify reaction kinetics mediated by biological versus geochemical reactions leading to U(VI) reduction and U(IV) re-oxidation, b) understand the influence of bioavailable iron on U(VI) reduction and U(IV) re-oxidation along the transverse mixing zones, c) determine how transverse mixing limitations and the presence of biomass in pores affects these reactions, and d) identify how microbial populations that develop along transverse mixing zones are influenced by the presence of iron and the concentration of electron donor. In the completed work, transverse mixing zones along plume margins were re-created in microfluidic pore networks, referred to as micromodels. We conducted a series of experiments that allowed us to distinguish among the hydraulic, biological, and geochemical mechanisms that contribute to U(VI) reduction, U(IV) re-oxidation, and U(VI) abiotic reaction with the limiting biological nutrient HP042-. This systematic approach may lead to a better understanding of U(VI) remediation, and better strategies for groundwater amendments to maximize remediation efficiency.« less

Observational Evidence for Mixing and Dust Condensation in Core-Collapse Supernovae

NASA Technical Reports Server (NTRS)

Wooden, Diane; Young, Richard E. (Technical Monitor)

1997-01-01

Recent findings of isotopic anomalies of Ca-44 (the decay product of Ti-44) and the enhanced ratio of Si-28/Si-30 in SiC grains X, TiC subgrains, and graphite dust grains within primitive meteorites provides strong evidence that these presolar grains came from core-collapse supernovae. The chemical composition of the presolar grains requires macroscopic mixing of newly nucleo-synthesized elements from explosive silicon burning at the innermost zone of the ejects to higher velocities where C exists and where C/O > 1 in either the outer edge of the oxygen zone or in the He-C zone. To date, the only core-collapse supernova observed to form dust is the brightest supernova of the past four centuries, SN1987A in the Large Magellanic Cloud. Observations of SN1987A confirm large scale macroscopic mixing occurs in the explosions of massive stars. Rayleigh-Taylor instabilities macroscopically mix most of the ejects into regions which are still chemically homogeneous and which cool with different time scales. Only small clumps in the ejects are microscopically mixed. Observations show that dust condensed in the ejects of SN1987A after approx.500 days in the Fe-rich gas. Neither silicates nor SiC grains were seen in the dust emission spectrum of SN1987A. SN1987A, the Rosetta Stone of core-collapse supernovae, shows that while the mixing required to explain presolar grains occurs, the rapid cooling of the Fe zone and the sustained high temperatures of the O-Si, O-C, and He-C zones favor the formation of iron-rich rather than oxygen- or carbon-rich grains.

Compositional Zoning in Kilauea Olivine: A Geochemical Tool for Investigating Magmatic Processes at Hawaiian Volcanoes

NASA Astrophysics Data System (ADS)

Lynn, Kendra J.

Olivine compositions and zoning patterns have been widely used to investigate the evolution of magmas from their source to the Earthfs surface. Modeling the formation of compositional zoning in olivine crystals has been used to retrieve timescales of magma residence, mixing, and transit. This dissertation is composed of three projects that apply diffusion chronometry principles to investigate how zoned olivine phenocrysts record magmatic processes at Hawaiian volcanoes. Olivine phenocrysts from K.lauea, the most active and thoroughly studied volcano in Hawaiei, are used to develop a better understanding of how Hawaiian olivine crystals record magmatic histories. This work begins by examining how crustal processes such as magma mixing and diffusive reequilibration can modify olivine compositions inherited from growth in parental magmas (Chapter 2). Diffusive re-equilibration of Fe-Mg, Mn, and Ni in olivine crystals overprints the chemical relationships inherited during growth, which strongly impacts interpretations about mantle processes and source components. These issues are further complicated by sectioning effects, where small (400 ƒEm along the c-axis) olivine crystals are more susceptible to overprinting compared to large (800 ƒEm) crystals. Olivine compositions and zoning patterns are then used to show that magmas during K.laueafs explosive Keanak.koei Tephra period (1500-1823 C.E.) were mixed and stored in crustal reservoirs for weeks to months prior to eruption (Chapter 3). Fe-Mg disequilibrium between olivine rims and their surrounding glasses show that a late-stage mixing event likely occurred hours to days prior to eruption, but the exact timescale is difficult to quantify using Fe-Mg and Ni diffusion. Lithium, a rapidly diffusing trace element in olivine, is modeled for the first time in a natural volcanic system to quantify this late-stage, short-duration mixing event (Chapter 4). Lithium zoning in olivine records both growth and diffusion processes that are affected by charge balancing requirements with growth zoning of P. Timescales from modeling diffuse Li zoning range from a few hours to three weeks, but most record short storage durations of four days or less. These timescales correspond to short storage periods after mixing. Thus, Li probably records the final perturbation of a magmatic system prior to eruption.

Use of a mixing model to investigate groundwater-surface water mixing and nitrogen biogeochemistry in the bed of a groundwater-fed river

NASA Astrophysics Data System (ADS)

Lansdown, Katrina; Heppell, Kate; Ullah, Sami; Heathwaite, A. Louise; Trimmer, Mark; Binley, Andrew; Heaton, Tim; Zhang, Hao

2010-05-01

The dynamics of groundwater and surface water mixing and associated nitrogen transformations in the hyporheic zone have been investigated within a gaining reach of a groundwater-fed river (River Leith, Cumbria, UK). The regional aquifer consists of Permo-Triassic sandstone, which is overlain by varying depths of glaciofluvial sediments (~15 to 50 cm) to form the river bed. The reach investigated (~250m long) consists of a series of riffle and pool sequences (Käser et al. 2009), with other geomorphic features such as vegetated islands and marginal bars also present. A network of 17 piezometers, each with six depth-distributed pore water samplers based on the design of Rivett et al. (2008), was installed in the river bed in June 2009. An additional 18 piezometers with a single pore water sampler were installed in the riparian zone along the study reach. Water samples were collected from the pore water samplers on three occasions during summer 2009, a period of low flow. The zone of groundwater-surface water mixing within the river bed sediments was inferred from depth profiles (0 to 100 cm) of conservative chemical species and isotopes of water with the collected samples. Sediment cores collected during piezometer installation also enabled characterisation of grain size within the hyporheic zone. A multi-component mixing model was developed to quantify the relative contributions of different water sources (surface water, groundwater and bank exfiltration) to the hyporheic zone. Depth profiles of ‘predicted' nitrate concentration were constructed using the relative contribution of each water source to the hyporheic and the nitrate concentration of the end members. This approach assumes that the mixing of different sources of water is the only factor controlling the nitrate concentration of pore water in the river bed sediments. Comparison of predicted nitrate concentrations (which assume only mixing of waters with different nitrate concentrations) with actual nitrate concentrations (measured from samples collected in the field) then allows patches of biogeochemical activity to be identified. The depth of the groundwater-surface water mixing zone was not uniform along the study reach or over the three sampling periods, varying from <10 to 50 cm in depth. The influence of factors such as the strength of groundwater upwelling, channel geomorphology, substrate composition (permeability) and river discharge on the extent of groundwater-surface mixing have been investigated. During the three field campaigns conducted, groundwater nitrate concentrations (100 cm) were higher than surface water nitrate concentrations (3.7 ± 0.4 mg N/L versus 2.0 ± 0.03 mg N/L; p < 0.001; n = 27), indicating that throughout the reach investigated groundwater will supply nitrate to the overlying water column unless nitrate attenuation occurs along the upwelling flow path. Actual (measured) pore water nitrate concentrations often differed from concentrations predicted using the mixing model, which suggests that biogeochemical transformations also affected nitrate concentrations in the hyporheic zone. The initial field data suggested that there were regions of both nitrate production and nitrate consumption in the subsurface sediments, and that these zones may extend beyond the depths commonly associated with the hyporheic zone. This research demonstrates that a multi-component mixing model can be used to identify possible hotspots of nitrate production or consumption in the bed of a groundwater-fed river. Käser, DH, Binley, A, Heathwaite, AL and Krause, S (2009) Spatio-temporal variations of hyporheic flow in a riffle-pool sequence. Hydrological Processes 23: 2138 - 2149. Rivett, MO, Ellis, PA, Greswell, RB, Ward, RS, Roche, RS, Cleverly, MG, Walker, C, Conran, D, Fitzgerald, PJ, Willcox, T and Dowle, J (2008) Cost-effective mini drive-point piezometers and multilevel samplers for monitoring the hyporheic zone. Quarterly Journal of Engineering Geology and Hydrogeology 41: 49 - 60.

Local hyperspectral data multisharpening based on linear/linear-quadratic nonnegative matrix factorization by integrating lidar data

NASA Astrophysics Data System (ADS)

Benhalouche, Fatima Zohra; Karoui, Moussa Sofiane; Deville, Yannick; Ouamri, Abdelaziz

2015-10-01

In this paper, a new Spectral-Unmixing-based approach, using Nonnegative Matrix Factorization (NMF), is proposed to locally multi-sharpen hyperspectral data by integrating a Digital Surface Model (DSM) obtained from LIDAR data. In this new approach, the nature of the local mixing model is detected by using the local variance of the object elevations. The hyper/multispectral images are explored using small zones. In each zone, the variance of the object elevations is calculated from the DSM data in this zone. This variance is compared to a threshold value and the adequate linear/linearquadratic spectral unmixing technique is used in the considered zone to independently unmix hyperspectral and multispectral data, using an adequate linear/linear-quadratic NMF-based approach. The obtained spectral and spatial information thus respectively extracted from the hyper/multispectral images are then recombined in the considered zone, according to the selected mixing model. Experiments based on synthetic hyper/multispectral data are carried out to evaluate the performance of the proposed multi-sharpening approach and literature linear/linear-quadratic approaches used on the whole hyper/multispectral data. In these experiments, real DSM data are used to generate synthetic data containing linear and linear-quadratic mixed pixel zones. The DSM data are also used for locally detecting the nature of the mixing model in the proposed approach. Globally, the proposed approach yields good spatial and spectral fidelities for the multi-sharpened data and significantly outperforms the used literature methods.

Semidiurnal temperature changes caused by tidal front movements in the warm season in seabed habitats on the georges bank northern margin and their ecological implications.

PubMed

Guida, Vincent G; Valentine, Page C; Gallea, Leslie B

2013-01-01

Georges Bank is a large, shallow feature separating the Gulf of Maine from the Atlantic Ocean. Previous studies demonstrated a strong tidal-mixing front during the warm season on the northern bank margin between thermally stratified water in the Gulf of Maine and mixed water on the bank. Tides transport warm water off the bank during flood tide and cool gulf water onto the bank during ebb tide. During 10 days in August 2009, we mapped frontal temperatures in five study areas along ∼100 km of the bank margin. The seabed "frontal zone", where temperature changed with frontal movment, experienced semidiurnal temperature maxima and minima. The tidal excursion of the frontal boundary between stratified and mixed water ranged 6 to 10 km. This "frontal boundary zone" was narrower than the frontal zone. Along transects perpendicular to the bank margin, seabed temperature change at individual sites ranged from 7.0°C in the frontal zone to 0.0°C in mixed bank water. At time series in frontal zone stations, changes during tidal cycles ranged from 1.2 to 6.1°C. The greatest rate of change (-2.48°C hr(-1)) occurred at mid-ebb. Geographic plots of seabed temperature change allowed the mapping of up to 8 subareas in each study area. The magnitude of temperature change in a subarea depended on its location in the frontal zone. Frontal movement had the greatest effect on seabed temperature in the 40 to 80 m depth interval. Subareas experiencing maximum temperature change in the frontal zone were not in the frontal boundary zone, but rather several km gulfward (off-bank) of the frontal boundary zone. These results provide a new ecological framework for examining the effect of tidally-driven temperature variability on the distribution, food resources, and reproductive success of benthic invertebrate and demersal fish species living in tidal front habitats.

Comparing the capitalisation benefits of light-rail transit and overlay zoning for single-family houses and condos by neighbourhood type in metropolitan Phoenix, Arizona.

PubMed

Atkinson-Palombo, Carol

2010-01-01

Light rail transit (LRT) is increasingly accompanied by overlay zoning which specifies the density and type of future development to encourage landscapes conducive to transit use. Neighbourhood type (based on land use mix) is used to partition data and investigate how pre-existing land use, treatment with a park-and-ride (PAR) versus walk-and-ride (WAR) station and overlay zoning interrelate. Hedonic models estimate capitalisation effects of LRT-related accessibility and overlay zoning on single-family houses and condos in different neighbourhoods for the system in metropolitan Phoenix, Arizona. Impacts differ by housing and neighbourhood type. Amenity-dominated mixed-use neighbourhoods-predominantly WAR communities-experience premiums of 6 per cent for single-family houses and over 20 per cent for condos, the latter boosted an additional 37 per cent by overlay zoning. Residential neighbourhoods-predominantly PAR communities-experience no capitalisation benefits for single-family houses and a discount for condos. The results suggest that land use mix is an important variable to select comparable neighbourhoods.

Application of jet-shear-layer mixing and effervescent atomization to the development of a low-NO(x) combustor. Ph.D. Thesis - Purdue Univ.

NASA Technical Reports Server (NTRS)

Colantonio, Renato Olaf

1993-01-01

An investigation was conducted to develop appropriate technologies for a low-NO(x), liquid-fueled combustor. The combustor incorporates an effervescent atomizer used to inject fuel into a premixing duct. Only a fraction of the combustion air is used in the premixing process to avoid autoignition and flashback problems. This fuel-rich mixture is introduced into the remaining combustion air by a rapid jet-shear-layer-mixing process involving radial fuel-air jets impinging on axial air jets in the primary combustion zone. Computational analysis was used to provide a better understanding of the fluid dynamics that occur in jet-shear-layer mixing and to facilitate a parametric analysis appropriate to the design of an optimum low-NO(x) combustor. A number of combustor configurations were studied to assess the key combustor technologies and to validate the modeling code. The results from the experimental testing and computational analysis indicate a low-NO(x) potential for the jet-shear-layer combustor. Key parameters found to affect NO(x) emissions are the primary combustion zone fuel-air ratio, the number of axial and radial jets, the aspect ratio and radial location of the axial air jets, and the radial jet inlet hole diameter. Each of these key parameters exhibits a low-NO(x) point from which an optimized combustor was developed. Using the parametric analysis, NO(x) emissions were reduced by a factor of 3 as compared with the emissions from conventional, liquid-fueled combustors operating at cruise conditions. Further development promises even lower NO(x) with high combustion efficiency.

Strength of the San Andreas Fault Zone: Insight From SAFOD Cuttings and Core

NASA Astrophysics Data System (ADS)

Tembe, S.; Lockner, D. A.; Solum, J. G.; Morrow, C. A.; Wong, T.; Moore, D. E.

2005-12-01

Cuttings acquired during drilling of the SAFOD scientific hole near Parkfield, California offer a continuous physical record of the lithology across the San Andreas fault (SAF) zone and provide the only complete set of samples available for laboratory testing. Guided by XRD clay mineral analysis and velocity and gamma logs, we selected washed cuttings from depths spanning the main hole from 1.85 to 3.0 km true vertical depth. Cuttings were chosen to represent primary lithologic units as well as significant shear zones, including candidates for the currently active SAF. To determine frictional properties triaxial sliding tests were conducted on cylindrical granite blocks containing sawcuts inclined at 30° and filled with 1 mm-thick sample gouge layers. Tests were run at constant effective normal stresses of 10 and 40 MPa and constant pore pressure of 1 MPa. Samples were sheared up to 10.4 mm at room temperature and velocities of 1, 0.1 and 0.01 μm/s. Stable sliding behavior and overall strain hardening were observed in all tests. The coefficient of friction typically showed a modest decrease with increasing effective normal stress and mostly velocity strengthening was observed. Preliminary results yield coefficients of friction, μ, which generally fell into two clusters spanning the range of 0.45 to 0.8. The higher values of friction (~0.7 - 0.8) corresponded to quartzofeldspathic samples derived from granodiorites and arkoses encountered in the drill hole. Lower values of friction (0.45 - 0.55) were observed at depth intervals interpreted as shear zones based on enriched clay content, reduced seismic velocities and increased gamma radiation. Arguments for a weak SAF suggest coseismic frictional strength of μ = 0.1 to 0.2 yet the actual fault zone materials studied here appear consistently stronger. At least two important limitations exist for inferring in-situ fault strength from cuttings. (1) Clays and weak minerals are preferentially lost during drilling and therefore undersampled in the cuttings and (2) cuttings are mixed as they travel up the borehole. To test the validity of this approach sliding tests were conducted on core samples obtained from a prominent fault zone at 2.56 km (10062 ft measured depth). Coefficient of friction was measured to be 0.42-0.5, notably weaker than that for cuttings tested at this depth (~0.6) but similar to values obtained for other shear zones. This difference between core and cuttings from the equivalent depth is likely due to mixing, resulting in the averaging of mechanical properties over a 1 to 10 foot interval. Nevertheless, we find good agreement in the strength of materials obtained from shallow shear zones, an indication that some weak mineral phases are preserved in the cuttings. While our findings indicate that meaningful mechanical data can be derived from the cuttings, it should be noted that these observations do not represent an exhaustive study of SAF frictional strength. We continue to explore the effectiveness of the present technique by a variety of methods. For example, estimates of lost clay fractions determined from XRD analysis of unwashed cuttings can be used in the application of approximate mixing laws to correct friction measurements. In addition, comparisons of strength of cuttings and corresponding sidewall cores will help refine our results. While the analysis of cuttings provides the best fault zone strength data to date, unresolved questions show the importance of collecting continuous core in Phase 3 drilling planned for 2007.

Formation of intermetallics at the interface of explosively welded Ni-Al multilayered composites during annealing

NASA Astrophysics Data System (ADS)

Ogneva, T. S.; Lazurenko, D. V.; Bataev, I. A.; Mali, V. I.; Esikov, M. A.; Bataev, A. A.

2016-04-01

The Ni-Al multilayer composite was fabricated using explosive welding. The zones of mixing of Ni and Al are observed at the composite interfaces after the welding. The composition of these zones is inhomogeneous. Continuous homogeneous intermetallic layers are formed at the interface after heat treatment at 620 °C during 5 h These intermetallic layers consist of NiAl3 and Ni2Al3 phases. The presence of mixed zones significantly accelerates the growth rate of intermetallic phases at the initial stages of heating.

Catalytic distillation process

DOEpatents

Smith, Jr., Lawrence A.

1982-01-01

A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Catalytic distillation process

DOEpatents

Smith, L.A. Jr.

1982-06-22

A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Rich catalytic injection

DOEpatents

Veninger, Albert [Coventry, CT

2008-12-30

A gas turbine engine includes a compressor, a rich catalytic injector, a combustor, and a turbine. The rich catalytic injector includes a rich catalytic device, a mixing zone, and an injection assembly. The injection assembly provides an interface between the mixing zone and the combustor. The injection assembly can inject diffusion fuel into the combustor, provides flame aerodynamic stabilization in the combustor, and may include an ignition device.

The Lunar-wide Effects of the Formation of Basins on the Megaregolith

NASA Technical Reports Server (NTRS)

Petro, . E.; Pieters, C. M.

2005-01-01

The surface of the Moon underwent an intense bombardment during the first approx.700 my of it s history (e.g. [1]). During this time at least 43 basins [1,2] and countless smaller craters were formed across the entire surface [1,3]. A quantitative assessment of the regolith as formed and modified by basins is discussed here. The formation of the basins (craters >300km in diameter) caused a significant amount of material to be excavated and redistributed across the surface of the Moon [4,5,6,7]. The material excavated by each individual basin was deposited and laterally mixed with the surrounding surface. This resulted in the development of a lunar-wide mixed zone of fragmented material, several kilometers thick [5,8,9]. This mixed zone was developed further by subsequent impacts resulting in a fragmental zone 1-2km thick called the megaregolith [10]. The initial zone of mixed material formed by the basins is not expected to be uniform across the surface of the Moon because of the varied size and random distribution of the basins. The main topographic ring of the 43 basins discussed by Wilhelms and Spudis [1,2] are illustrated in Figure 1.

Remote sensing in the mixing zone. [water pollution in Wisconsin

NASA Technical Reports Server (NTRS)

Villemonte, J. R.; Hoopes, J. A.; Wu, D. S.; Lillesand, T. M.

1973-01-01

Characteristics of dispersion and diffusion as the mechanisms by which pollutants are transported in natural river courses were studied with the view of providing additional data for the establishment of water quality guidelines and effluent outfall design protocols. Work has been divided into four basic categories which are directed at the basic goal of developing relationships which will permit the estimation of the nature and extent of the mixing zone as a function of those variables which characterize the outfall structure, the effluent, and the river, as well as climatological conditions. The four basic categories of effort are: (1) the development of mathematical models; (2) laboratory studies of physical models; (3) field surveys involving ground and aerial sensing; and (4) correlation between aerial photographic imagery and mixing zone characteristics.

Apparatus for converting hydrocarbon fuel into hydrogen gas and carbon dioxide

DOEpatents

Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.

2002-01-01

Hydrocarbon fuel reformer 100 suitable for producing synthesis hydrogen gas from reactions with hydrocarbons fuels, oxygen, and steam. A first tube 108 has a first tube inlet 110 and a first tube outlet 112. The first tube inlet 110 is adapted for receiving a first mixture including an oxygen-containing gas and a first fuel. A partially oxidized first reaction reformate is directed out of the first tube 108 into a mixing zone 114. A second tube 116 is annularly disposed about the first tube 108 and has a second tube inlet 118 and a second tube outlet 120. The second tube inlet 118 is adapted for receiving a second mixture including steam and a second fuel. A steam reformed second reaction reformate is directed out of the second tube 116 and into the mixing zone 114. From the mixing zone 114, the first and second reaction reformates may be directed into a catalytic reforming zone 144 containing a reforming catalyst 147.

Microstructure and hydrogen induced failure mechanisms in iron-nickel weldments

NASA Astrophysics Data System (ADS)

Fenske, Jamey Alan

A recent series of inexplicable catastrophic failures of specific subsea dissimilar metal Fe-Ni butter welds has illuminated a fundamental lack of understanding of both the microstructure created along the fusion line as well as its impact on the hydrogen susceptibility of these interfaces. In order to remedy this, the present work compares and contrasts the microstructure and hydrogen-induced fracture morphology of AISI 8630-IN 625 and F22-IN 625 dissimilar metal weld interfaces as a function of post-weld heat treatment duration. A variety of techniques were used to study details of both the microstructure and fracture morphology including optical microscopy, scanning electron microscopy, secondary ion mass spectrometry, transmission electron microscopy, electron backscatter diffraction, and energy dispersive x-ray spectroscopy. For both systems, the microstructure along the weld interface consisted of a coarse grain heat-affected zone in the Fe-base metal followed by discontinuous martensitic partially-mixed zones and a continuous partially-mixed zone on the Ni-side of the fusion line. Within the partially mixed zone on the Ni-side there exists a 200 nm-wide transition zone within a 20 mum-wide planar solidification region followed by a cellular dendritic region with Nb-Mo rich carbides decorating the dendrite boundaries. The size, area fraction and composition of the discontinuous PMZ were determined to be controlled by uneven mixing in the liquid weld pool influenced by convection currents produced from the welding procedure. The virgin martensitic microstructure produced in these regions is formed as consequence of a both the local composition and the post-weld heat treatment. The local higher Ni content results in these regions being retransformed into austenite during the post-weld heat treatment and then virgin martensite while cooling to room temperature. Although there were differences in the volume of the discontinuous partially mixed-zones, the major difference in the weld metal interfaces was the presence of M 7C3 precipitates in the planar solidification region. The formation of these precipitates, which were found in what was previously referred to as the "featureless-zone," were determined to be dependent on the carbon content of the Fe-base metal and the duration of the post-weld heat treatment. A high density of these ordered 100 nm-long by 10 nm-wide needle-like precipitates were found in the AISI 8630-IN 625 weldment in the 10 hour post-weld heat treatment condition while only the initial stages of their nucleation were evident in the F22-IN 625 15 hour post-weld heat treatment specimen. The study of the fractured specimens revealed that the M7C 3 carbides play a key role in the susceptibility to hydrogen embrittlement of the Fe-Ni butter weldments. The fractures initially nucleate along the isolated Fe-base metal -- discontinuous partially mixed zone interfaces. The M7C3 carbides accumulate hydrogen and then provide a low energy fracture path between the discontinuous partially mixed zones leading to catastrophic failure. The result is a fracture morphology that alternates between flat regions produced by fracture along the discontinuous partially mixed zones and cleavage-like fracture regions produced by fracture along the ordered carbide matrix interfaces.

Antimicrobial efficacy of octenidine hydrochloride, MTAD and chlorhexidine gluconate mixed with calcium hydroxide.

PubMed

Tirali, Resmiye Ebru; Gulsahi, Kamran; Cehreli, Sevi Burcak; Karahan, Zeynep Ceren; Uzunoğlu, Emel; Elhan, Atilla

2013-05-01

The aim of this in vitro study was to investigate whether mixing with calcium hydroxide [Ca(OH)2] affects the antimicrobial action of Octenidine hydrochloride (Octenisept), MTAD and chlorhexidine against Enterococcus faecalis and Candida albicans. Freshly grown cultures of Enterococcus faecalis, Candida albicans and a mixture of both strains were incubated in agar plates containing brain-heart infusion broth (BHIB). Zones of inhibition were measured at 24 and 48 hours. Statistical analysis was performed using Mann-Whitney U test and Kruskal-Wallis one-way analysis of variance (ANOVA, both p=0.05). Mixing with Ca(OH)2 significantly increased the antibacterial effect of Octenisept (p<0.05), but did not alter its antifungal activity. Only chlorhexidine showed more antibacterial and antifungal efficiency compared to its Ca(OH)2-mixed version (both p<0.05). Mixing with Ca(OH)2 decreased the antibacterial efficacy of MTAD, but increased its antifungal effect (both p<0.05). These results demonstrate the differential effects of Ca(OH)2 addition on the antimicrobial action of the tested endodontic medicaments in vitro. Ca(OH)2 was as effective as its combination with all of the tested medicaments.

Environment of ore deposition in the creede mining district, San Juan Mountains, Colorado: Part V. Epithermal mineralization from fluid mixing in the OH vein

USGS Publications Warehouse

Hayba, D.O.

1997-01-01

Detailed fluid inclusion studies on coarse-grained sphalerite from the OH vein, Creede, Colorado, have shown that the abrupt color changes between growth zones correspond to abrupt changes in the nature of the ore fluids. Within each growth zone, however, the composition of the fluids remained constant. The base of a distinctive orange-brown growth zone marks a sharp increase in both temperature and salinity relative to the preceding yellow-white zone. The orange-brown growth zone can be correlated along much of the vein and is believed to represent a time-stratigraphic interval. Along the vein, temperatures and salinities of fluid inclusions within this interval show a systematic decrease from about 285??C and 11.5 wt percent NaCl equiv near the base of the vein to about 250??C and 8 wt percent NaCl equiv, respectively, near the top of the vein. The iron concentration of this sphalerite growth zone shows a similar pattern, decreasing from about 2.8 to 1.2 mole percent FeS. When plotted on an enthalpy-salinity diagram, the fluid inclusion data define a spatial trend indicating the progressive mixing of deeply circulating hydrothermal brines with overlying, dilute ground waters. The hydrothermal brines entered the OH vein from below at a temperature, salinity, and density of approximately 285??C, 11.5 wt percent NaCl equiv, and 860 kg/m3, respectively, whereas the overlying ground waters appear to have been preheated to roughly 150??C and had an assumed salinity of 0 wt percent and a density of 920 kg/m3. The greater density of the heated ground water promoted mixing with the hydrothermal brine within the open fractures, causing sphalerite deposition. Although there were also episodes of boiling during vein mineralization, boiling appears unimportant for this sphalerite. Isotopic evidence and geochemical modeling studies also indicate that mixing was the depositional mechanism for sphalerite. An important aspect of the mixing hydrology of the Creede system involves an aquitard overlying the OH vein. This low permeability zone restricted the flow of ground water into the vein from above and forced the upwelling hydrothermal fluids to flow laterally along the vein. The mixing environment thus occurred along the interface between a deeply circulating hydrothermal convection cell and a topographically driven shallow ground-water system.

Computational and experimental analysis of the flow in an annular centrifugal contactor

NASA Astrophysics Data System (ADS)

Wardle, Kent E.

The annular centrifugal contactor has been developed for solvent extraction processes for recycling used nuclear fuel. The compact size and high efficiency of these contactors have made them the choice for advanced reprocessing schemes and a key equipment for a proposed future advanced fuel cycle facility. While a sufficient base of experience exists to facilitate successful operation of current contactor technology, a more complete understanding of the fluid flow within the contactor would enable further advancements in design and operation of future units and greater confidence for use of such contactors in a variety of other solvent extraction applications. This research effort has coupled computational fluid dynamics modeling with a variety of experimental measurements and observations to provide a valid detailed analysis of the flow within the centrifugal contactor. CFD modeling of the free surface flow in the annular mixing zone using the Volume of Fluid (VOF) volume tracking method combined with Large Eddy Simulation (LES) of turbulence was found to have very good agreement with the experimental measurements and observations. A detailed study of the flow and mixing for different housing vane geometries was performed and it was found that the four straight mixing vane geometry had greater mixing for the flow rate simulated and more predictable operation over a range of low to moderate flow rates. The separation zone was also modeled providing a useful description of the flow in this region and identifying critical design features. It is anticipated that this work will form a foundation for additional efforts at improving the design and operation of centrifugal contactors and provide a framework for progress towards simulation of solvent extraction processes.

Comparison of Mixing Calculations for Reacting and Non-Reacting Flows in a Cylindrical Duct

NASA Technical Reports Server (NTRS)

Oechsle, V. L.; Mongia, H. C.; Holdeman, J. D.

1994-01-01

A production 3-D elliptic flow code has been used to calculate non-reacting and reacting flow fields in an experimental mixing section relevant to a rich burn/quick mix/lean burn (RQL) combustion system. A number of test cases have been run to assess the effects of the variation in the number of orifices, mass flow ratio, and rich-zone equivalence ratio on the flow field and mixing rates. The calculated normalized temperature profiles for the non-reacting flow field agree qualitatively well with the normalized conserved variable isopleths for the reacting flow field indicating that non-reacting mixing experiments are appropriate for screening and ranking potential rapid mixing concepts. For a given set of jet momentum-flux ratio, mass flow ratio, and density ratio (J, MR, and DR), the reacting flow calculations show a reduced level of mixing compared to the non-reacting cases. In addition, the rich-zone equivalence ratio has noticeable effect on the mixing flow characteristics for reacting flows.

a New Approach for Complete Mixing by Transverse and Streamwise Flow Motions in Micro-Channels

NASA Astrophysics Data System (ADS)

Wang, Muh-Rong; Dai, Chiau-Yi; Huang, Yang-Sheng

Mixing control is an important issue in micro-fluid chip applications, such as μTAS (Micro-Total Analysis System) or LOC (Lab-on-Chip) because the flow at micro-scale is highly laminar. Several flow control schemes had been developed for complete mixing in the micro-channels in the past decades. However, most of the mixing control schemes are performed by utilizing specific excitation devices, such as electrokinetic, magnetic or pressure drivers. This paper investigates a new control scheme which is composed of a series of flow manipulation by changing the pressure at the two inlets of the micromixer as the external excitation. The fluids from two inlets are introduced to a square mixing chamber, which provides a space where the streamwise and transverse flow motions take place. The results show that the micromixer can be used to produce a large recirculation zone with series of small transverse fringes under external excitations. It is found that this new flow pattern enhances mixing processes at the micro-scale. A complete mixing can be achieved under appropriate flow control with the corresponding design.

Correlation Between Intercritical Heat-Affected Zone and Type IV Creep Damage Zone in Grade 91 Steel

NASA Astrophysics Data System (ADS)

Wang, Yiyu; Kannan, Rangasayee; Li, Leijun

2018-04-01

A soft zone in Cr-Mo steel weldments has been reported to accompany the infamous Type IV cracking, the highly localized creep damage in the heat-affected zone of creep-resistant steels. However, the microstructural features and formation mechanism of this soft zone are not well understood. In this study, using microhardness profiling and microstructural verification, the initial soft zone in the as-welded condition was identified to be located in the intercritical heat-affected zone of P91 steel weldments. It has a mixed structure, consisting of Cr-rich re-austenitized prior austenite grains and fine Cr-depleted, tempered martensite grains retained from the base metal. The presence of these further-tempered retained grains, originating from the base metal, is directly responsible for the hardness reduction of the identified soft zone in the as-welded condition. The identified soft zone exhibits a high location consistency at three thermal stages. Local chemistry analysis and thermodynamic calculation show that the lower chromium concentrations inside these retained grains thermodynamically decrease their potentials for austenitic transformation during welding. Heterogeneous grain growth is observed in the soft zone during postweld heat treatment. The mismatch of strengths between the weak Cr-depleted grains and strong Cr-rich grains enhances the creep damage. Local deformation of the weaker Cr-depleted grains accelerates the formation of creep cavities.

Groundwater geochemistry of Isla de Mona, Puerto Rico

USGS Publications Warehouse

Wicks, C.M.; Troester, J.W.

1998-01-01

In this study, we explore the differences between the hydrogeochemical processes observed in a setting that is open to input from the land surface and in a setting that is closed with respect to input from the land surface. The closed setting was a water-filled passage in a cave. Samples of groundwater and of a solid that appeared to be suspended in the relatively fresh region of saline-freshwater mixing zone were collected. The solid was determined to be aragonite. Based on the analyses of the composition and saturation state of the groundwater, the mixing of fresh and saline water and precipitation of aragonite are the controlling geochemical processes in this mixing zone. We found no evidence of sulfate reduction. Thus, this mixing zone is similar to that observed in Caleta Xel Ha, Quintana Roo, also a system that is closed with respect to input from the land surface. The open setting was an unconfined aquifer underlying the coastal plain along which four hand-dug wells are located. Two wells are at the downgradient ends of inferred flowpaths and one is along a flowpath. The composition of the groundwater in the downgradient wells is sulfide-rich and brackish. In contrast, at the well located along a flow line, the groundwater is oxygenated and brackish. All groundwater is oversaturated with respect to calcite, aragonite, and dolomite. The composition is attributed to mixing of fresh and saline groundwater, CO2 outgassing, and sulfate reduction. This mixing zone is geochemically similar to that observed in blue holes and cenotes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsigabu Gebrehiwet; James R. Henriksen; Luanjing Guo

Multi-component mineral precipitation in porous, subsurface environments is challenging to simulate or engineer when in situ reactant mixing is controlled by diffusion. In contrast to well-mixed systems, the conditions that favor mineral precipitation in porous media are distributed along chemical gradients, which evolve spatially due to concurrent mineral precipitation and modification of solute transport in the media. The resulting physical and chemical characteristics of a mixing/precipitation zone are a consequence of coupling between transport and chemical processes, and the distinctive properties of individual chemical systems. We examined the spatial distribution of precipitates formed in “double diffusion” columns for two chemicalmore » systems, calcium carbonate and calcium phosphate. Polyacrylamide hydrogel was used as a low permeability, high porosity medium to maximize diffusive mixing and minimize pressure- and density-driven flow between reactant solutions. In the calcium phosphate system, multiple, visually dense and narrow bands of precipitates were observed that were reminiscent of previously reported Liesegang patterns. In the calcium carbonate system, wider precipitation zones characterized by more sparse distributions of precipitates and a more open channel structure were observed. In both cases, formation of precipitates inhibited, but did not necessarily eliminate, continued transport and mixing of the reactants. A reactive transport model with fully implicit coupling between diffusion, chemical speciation and precipitation kinetics, but where explicit details of nucleation processes were neglected, was able to qualitatively simulate properties of the precipitation zones. The results help to illustrate how changes in the physical properties of a precipitation zone depend on coupling between diffusion-controlled reactant mixing and chemistry-specific details of precipitation kinetics.« less

Diagenesis of the Oligocene-Miocene rocks of the Upper Floridan and Intermediate aquifer systems by meteoric and mixing-zone waters in southwest Florida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weedman, S.D.; McCartan, L.

1993-03-01

Optical and SEM of samples from 6 cores of Oligocene and Miocene rocks that compose portions of the Florida and Intermediate aquifers and the intervening semiconfining unit documents meteoric and mixing-zone (seawater and fresh carbonate ground water) diagenesis inferred to have occurred over several cycles of sea level change. Dolomite, limestone, sandstone, and claystone of the Suwannee Formation and the Arcadia Formation (Hawthorn Group) were examined. Core samples from time-equivalent strata in two E--W transects in Manatee, Hardee, Highlands, Sarasota, and DeSoto Counties are estimated to be 16--33 Ma on the basis of [sup 87]Sr/[sup 86]Sr ratios from unaltered molluskmore » shells and by molluscan biostratigraphy. Lithostratigraphic correlations are based on examination of 19 cores, 62 thin sections, 60 geophysical logs, and mineralogy determined by X-ray diffraction. Diagenetic indicators that the authors tracked petrographically include shell micritization, shell dissolution, equant and (or) fibrous CaCO[sub 3] cement, neomorphism, dolomite, etched phosphate grains, echinoderm fragment syntaxial overgrowths, and amorphous silica pore lining. Infiltration of meteoric water caused dissolution of carbonate minerals, especially aragonite, and precipitation of equant calcite crystals in voids of dissolved fossils and in pore spaces between grains. The silica was precipitated as pore linings in zones having soil textures. Observed replacement of calcite by limpid dolomite is consistent with modeling predictions of mixing-zone diagenesis. Etched crystals of limpid dolomite may indicate freshwater dissolution of a mixing-zone precipitate. Mapping of regional unconformities revealed pronounced thickening and thinning of some units. Evidence of meteoric water diagenesis is observed in the upper 600 ft of the transects examined. Evidence of mixing-zone diagenesis is observed at varying depths, but appears to increase in abundance and thickness toward the west.« less

Fast ground-water mixing and basal recharge in an unconfined, alluvial aquifer, Konza LTER Site, Northeastern Kansas

USGS Publications Warehouse

Macpherson, G.L.; Sophocleous, M.

2004-01-01

Ground-water chemistry and water levels at three levels in a well nest were monitored biweekly for two and a half years in a shallow unconfined floodplain aquifer in order to study the dynamics of such shallow aquifers. The aquifer, in northeastern Kansas, consists of high porosity, low hydraulic conductivity fine-grained sediments dominated by silt and bounded by fractured limestone and shale bedrock. Results show that the aquifer underwent chemical stratification followed by homogenization three times during the study period. The length of time between maximum stratification and complete homogenization was 3-5 months. The chemical parameters most useful for demonstrating the mixing trends were dissolved nitrate and sulfate. Higher nitrate concentrations were typical of unsaturated zone water and were sourced from fertilizer applied to the cultivated fields on the floodplain. Variations in sulfate concentrations are attributed to dissolution of rare gypsum in limestone bedrock and variable evapoconcentration in the unsaturated zone. The mixing of three chemically different waters (entrained, unsaturated-zone water; water entering the base of the floodplain aquifer; and water in residence before each mixing event) was simulated. The resident water component for each mixing event was a fixed composition based on measured water chemistry in the intermediate part of the aquifer. The entrained water composition was calculated using a measured composition of the shallow part of the aquifer and measurements of soil-water content in the unsaturated zone. The incoming basal water composition and the fractions of each mixing component were fitted to match the measured chemistry at the three levels in the aquifer. A conceptual model for this site explains: (1) rapid water-level rises, (2) water-chemistry changes at all levels in the aquifer coincident with the water-level rises, (3) low measured hydraulic conductivity of the valley fill and apparent lack of preferential flow pathways, (4) minuscule amounts of unsaturated-zone recharge, and (5) dissolved oxygen peaks in the saturated zone lagging water-level peaks. We postulate that rainfall enters fractures in bedrock adjacent to the floodplain. This recharge water moves rapidly through the fractured bedrock into the base of the floodplain aquifer. The recharge event through the bedrock causes a rapid rise in water level in the floodplain aquifer, and the chemistry of the deepest water in the floodplain aquifer changes at that time. The rising water also entrains slow-moving, nitrate-rich, unsaturated-zone water, altering the chemistry of water in the shallow part of the aquifer. Vertical chemical stratification in the aquifer is thus created by the change in water chemistry in the upper and lower parts of the saturated zone. As the water level begins to decline, the aquifer undergoes mixing that eventually results in homogeneous water chemistry. The rise in water level from the recharge event also displaces gas from the unsaturated zone that is then replaced as the water level declines following the recharge event. This new, oxygen-rich vadose-zone air equilibrates rapidly with saturated-zone water, resulting in a dissolved oxygen pulse in the ground water that peaks one-half to 2 months after the water-level peak. This oxygen pulse subsequently declines over a period of 2-6 months. ?? 2003 Elsevier B.V. All rights reserved.

The prediction of radiofrequency ablation zone volume using vascular indices of 3-dimensional volumetric colour Doppler ultrasound in an in vitro blood-perfused bovine liver model

PubMed Central

Lanctot, Anthony C; McCarter, Martin D; Roberts, Katherine M; Glueck, Deborah H; Dodd, Gerald D

2017-01-01

Objective: To determine the most reliable predictor of radiofrequency (RF) ablation zone volume among three-dimensional (3D) volumetric colour Doppler vascular indices in an in vitro blood-perfused bovine liver model. Methods: 3D colour Doppler volume data of the local hepatic parenchyma were acquired from 37 areas of 13 bovine livers connected to an in vitro oxygenated blood perfusion system. Doppler vascular indices of vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were obtained from the volume data using 3D volume analysis software. 37 RF ablations were performed at the same locations where the ultrasound data were obtained from. The relationship of these vascular indices and the ablation zone volumes measured from gross specimens were analyzed using a general linear mixed model fit with random effect for liver and backward stepwise regression analysis. Results: FI was significantly associated with ablation zone volumes measured on gross specimens (p = 0.0047), but explained little of the variance (Rβ2 = 0.21). Ablation zone volume decreased by 0.23 cm3 (95% confidence interval: −0.38, −0.08) for every 1 increase in FI. Neither VI nor VFI was significantly associated with ablation zone volumes (p > 0.05). Conclusion: Although FI was associated with ablation zone volumes, it could not sufficiently explain their variability, limiting its clinical applicability. VI, FI and VFI are not clinically useful in the prediction of RF ablation zone volume in the liver. Advances in knowledge: Despite a significant association of FI with ablation zone volumes, VI, FI and VFI cannot be used for their prediction. Different Doppler vascular indices need to be investigated for clinical use. PMID:27925468

Communities on the Move: Pedestrian-Oriented Zoning as a Facilitator of Adult Active Travel to Work in the United States.

PubMed

Chriqui, Jamie F; Leider, Julien; Thrun, Emily; Nicholson, Lisa M; Slater, Sandy

2016-01-01

Communities across the United States have been reforming their zoning codes to create pedestrian-friendly neighborhoods with increased street connectivity, mixed use and higher density, open space, transportation infrastructure, and a traditional neighborhood structure. Zoning code reforms include new urbanist zoning such as the SmartCode, form-based codes, transects, transportation and pedestrian-oriented developments, and traditional neighborhood developments. To examine the relationship of zoning code reforms and more active living--oriented zoning provisions with adult active travel to work via walking, biking, or by using public transit. Zoning codes effective as of 2010 were compiled for 3,914 municipal-level jurisdictions located in 471 counties and 2 consolidated cities in 48 states and the District of Columbia, and that collectively covered 72.9% of the U.S. population. Zoning codes were evaluated for the presence of code reform zoning and nine pedestrian-oriented zoning provisions (1 = yes): sidewalks, crosswalks, bike-pedestrian connectivity, street connectivity, bike lanes, bike parking, bike-pedestrian trails/paths, mixed-use development, and other walkability/pedestrian orientation. A zoning scale reflected the number of provisions addressed (out of 10). Five continuous outcome measures were constructed using 2010-2014 American Community Survey municipal-level 5-year estimates to assess the percentage of workers: walking, biking, walking or biking, or taking public transit to work OR engaged in any active travel to work. Regression models controlled for municipal-level socioeconomic characteristics and a GIS-constructed walkability scale and were clustered on county with robust standard errors. Adjusted models indicated that several pedestrian-oriented zoning provisions were statistically associated (p < 0.05 or lower) with increased rates of walking, biking, or engaging in any active travel (walking, biking, or any active travel) to work: code reform zoning, bike parking (street furniture), bike lanes, bike-pedestrian trails/paths, other walkability, mixed-use zoning, and a higher score on the zoning scale. Public transit use was associated with code reform zoning and a number of zoning measures in Southern jurisdictions but not in non-Southern jurisdictions. As jurisdictions revisit their zoning and land use policies, they may want to evaluate the pedestrian-orientation of their zoning codes so that they can plan for pedestrian improvements that will help to encourage active travel to work.

Regional Survey of Structural Properties and Cementation Patterns of Fault Zones in the Northern Part of the Albuquerque Basin, New Mexico - Implications for Ground-Water Flow

USGS Publications Warehouse

Minor, Scott A.; Hudson, Mark R.

2006-01-01

Motivated by the need to document and evaluate the types and variability of fault zone properties that potentially affect aquifer systems in basins of the middle Rio Grande rift, we systematically characterized structural and cementation properties of exposed fault zones at 176 sites in the northern Albuquerque Basin. A statistical analysis of measurements and observations evaluated four aspects of the fault zones: (1) attitude and displacement, (2) cement, (3) lithology of the host rock or sediment, and (4) character and width of distinctive structural architectural components at the outcrop scale. Three structural architectural components of the fault zones were observed: (1) outer damage zones related to fault growth; these zones typically contain deformation bands, shear fractures, and open extensional fractures, which strike subparallel to the fault and may promote ground-water flow along the fault zone; (2) inner mixed zones composed of variably entrained, disrupted, and dismembered blocks of host sediment; and (3) central fault cores that accommodate most shear strain and in which persistent low- permeability clay-rich rocks likely impede the flow of water across the fault. The lithology of the host rock or sediment influences the structure of the fault zone and the width of its components. Different grain-size distributions and degrees of induration of the host materials produce differences in material strength that lead to variations in width, degree, and style of fracturing and other fault-related deformation. In addition, lithology of the host sediment appears to strongly control the distribution of cement in fault zones. Most faults strike north to north-northeast and dip 55? - 77? east or west, toward the basin center. Most faults exhibit normal slip, and many of these faults have been reactivated by normal-oblique and strike slip. Although measured fault displacements have a broad range, from 0.9 to 4,000 m, most are <100 m, and fault zones appear to have formed mainly at depths less than 1,000 m. Fault zone widths do not exceed 40 m (median width = 15.5 m). The mean width of fault cores (0.1 m) is nearly one order of magnitude less than that of mixed zones (0.75 m) and two orders of magnitude less than that of damage zones (9.7 m). Cements, a proxy for localized flow of ancient ground water, are common along fault zones in the basin. Silica cements are limited to faults that are near and strike north to northwest toward the Jemez volcanic field north of the basin, whereas carbonate fault cements are widely distributed. Coarse sediments (gravel and sand) host the greatest concentrations of cement within fault zones. Cements fill some extension fractures and, to a lesser degree, are concentrated along shear fractures and deformation bands within inner damage zones. Cements are commonly concentrated in mixed zones and inner damage zones on one side of a fault and thus are asymmetrically distributed within a fault zone, but cement does not consistently lie on the basinward side of faults. From observed spatial patterns of asymmetrically distributed fault zone cements, we infer that ancient ground-water flow was commonly localized along, and bounded by, faults in the basin. It is apparent from our study that the Albuquerque Basin contains a high concentration of faults. The geometry of, internal structure of, and cement and clay distribution in fault zones have created and will continue to create considerable heterogeneity of permeability within the basin aquifers. The characteristics and statistical range of fault zone features appear to be predictable and consistent throughout the basin; this predictability can be used in ground-water flow simulations that consider the influence of faults.

Assessment of performing an MST strike in Tank 21H

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poirier, Michael R.

2014-09-29

Previous Savannah River National Laboratory (SRNL) tank mixing studies performed for the Small Column Ion Exchange (SCIX) project have shown that 3 Submersible Mixer Pumps (SMPs) installed in Tank 41 are sufficient to support actinide removal by MST sorption as well as subsequent resuspension and removal of settled solids. Savannah River Remediation (SRR) is pursuing MST addition into Tank 21 as part of the Large Tank Strike (LTS) project. The preliminary scope for LTS involves the use of three standard slurry pumps (installed in N, SE, and SW risers) in a Type IV tank. Due to the differences in tankmore » size, internal interferences, and pump design, a separate mixing evaluation is required to determine if the proposed configuration will allow for MST suspension and strontium and actinide sorption. The author performed the analysis by reviewing drawings for Tank 21 [W231023] and determining the required cleaning radius or zone of influence for the pumps. This requirement was compared with previous pilot-scale MST suspension data collected for SCIX that determined the cleaning radius, or zone of influence, as a function of pump operating parameters. The author also reviewed a previous Tank 50 mixing analysis that examined the ability of standard slurry pumps to suspend sludge particles. Based on a review of the pilot-scale SCIX mixing tests and Tank 50 pump operating experience, three standard slurry pumps should be able to suspend sludge and MST to effectively sorb strontium and actinides onto the MST. Using the SCIX data requires an assumption about the impact of cooling coils on slurry pump mixing. The basis for this assumption is described in this report. Using the Tank 50 operating experience shows three standard slurry pumps should be able to suspend solids if the shear strength of the settled solids is less than 160 Pa. Because Tank 21 does not contain cooling coils, the shear strength could be larger.« less

Performance of a Model Rich Burn-quick Mix-lean Burn Combustor at Elevated Temperature and Pressure

NASA Technical Reports Server (NTRS)

Peterson, Christopher O.; Sowa, William A.; Samuelsen, G. S.

2002-01-01

As interest in pollutant emission from stationary and aero-engine gas turbines increases, combustor engineers must consider various configurations. One configuration of increasing interest is the staged, rich burn - quick mix - lean burn (RQL) combustor. This report summarizes an investigation conducted in a recently developed high pressure gas turbine combustor facility. The model RQL combustor was plenum fed and modular in design. The fuel used for this study is Jet-A which was injected from a simplex atomizer. Emission (CO2, CO, O2, UHC, NOx) measurements were obtained using a stationary exit plane water-cooled probe and a traversing water-cooled probe which sampled from the rich zone exit and the lean zone entrance. The RQL combustor was operated at inlet temperatures ranging from 367 to 700 K, pressures ranging from 200 to 1000 kPa, and combustor reference velocities ranging from 10 to 20 m/s. Variations were also made in the rich zone and lean zone equivalence ratios. Several significant trends were observed. NOx production increased with reaction temperature, lean zone equivalence ratio and residence time and decreased with increased rich zone equivalence ratio. NOx production in the model RQL combustor increased to the 0.4 power with increased pressure. This correlation, compared to those obtained for non-staged combustors (0.5 to 0.7), suggests a reduced dependence on NOx on pressure for staged combustors. Emissions profiles suggest that rich zone mixing is not uniform and that the rich zone contributes on the order of 16 percent to the total NOx produced.

Effects of stratification, organic matter remineralization and bathymetry on summertime oxygen distribution in the Bohai Sea, China

NASA Astrophysics Data System (ADS)

Zhao, Hua-De; Kao, Shuh-Ji; Zhai, Wei-Dong; Zang, Kun-Peng; Zheng, Nan; Xu, Xue-Mei; Huo, Cheng; Wang, Ju-Ying

2017-02-01

The Bohai Sea, a semi-enclosed shallow coastal sea with increasing nutrient loads, is susceptible to seasonal oxygen deficiency in its bottom waters, similar to many other areas of the worlds' coastal oceans. We examined the dissolved oxygen (DO) distribution in the Bohai during August 2014. Two oxygen-deficient zones (DO<92 μmol O2 kg-1) with a minimum DO of 80 μmol O2 kg-1 were documented. The area and volume of bottom oxygen-deficient water were 756 km2 and 7820×106 m3, with a mean thickness of 10 m. Thus, the Bohai is second to the Changjiang estuary in its oxygen-deficient zone size among China's coastal waters. We classified three hydrographic areas that dictated the distribution of DO: 1) the shallow well-mixed zone; 2) the laterally-open stratified zone; and 3) the isolated stratified zone. Vertical mixing dominated the shallow well-mixed zone leading to homogeneous DO in the water column. The laterally-open stratified zone was influenced by high DO and low temperature inflow through the northern Bohai Strait. The isolated stratified zones, i.e., the low DO areas, were found in depressed regions. The stoichiometric relationship between DO consumption and the corresponding enrichment of dissolved inorganic carbon suggested that the aerobic respiration of organic matter contributed to the oxygen-depletion in the isolated stratified zone. Overall, the bottom DO distribution in the Bohai system was controlled largely by lateral DO exchange modified by bathymetric features, while superimposed on that was the build-up of stratification caused by summer heating and the remineralization of organics sourced from spring phytoplankton bloom.

Primitive andesites from the Taupo Volcanic Zone formed by magma mixing

NASA Astrophysics Data System (ADS)

Beier, Christoph; Haase, Karsten M.; Brandl, Philipp A.; Krumm, Stefan H.

2017-05-01

Andesites with Mg# >45 erupted at subduction zones form either by partial melting of metasomatized mantle or by mixing and assimilation processes during melt ascent. Primitive whole rock basaltic andesites from the Pukeonake vent in the Tongariro Volcanic Centre in New Zealand's Taupo Volcanic Zone contain olivine, clino- and orthopyroxene, and plagioclase xeno- and antecrysts in a partly glassy matrix. Glass pools interstitial between minerals and glass inclusions in clinopyroxene, orthopyroxene and plagioclase as well as matrix glasses are rhyolitic to dacitic indicating that the melts were more evolved than their andesitic bulk host rock analyses indicate. Olivine xenocrysts have high Fo contents up to 94%, δ18O(SMOW) of +5.1‰, and contain Cr-spinel inclusions, all of which imply an origin in equilibrium with primitive mantle-derived melts. Mineral zoning in olivine, clinopyroxene and plagioclase suggest that fractional crystallization occurred. Elevated O isotope ratios in clinopyroxene and glass indicate that the lavas assimilated sedimentary rocks during stagnation in the crust. Thus, the Pukeonake andesites formed by a combination of fractional crystallization, assimilation of crustal rocks, and mixing of dacite liquid with mantle-derived minerals in a complex crustal magma system. The disequilibrium textures and O isotope compositions of the minerals indicate mixing processes on timescales of less than a year prior to eruption. Similar processes may occur in other subduction zones and require careful study of the lavas to determine the origin of andesite magmas in arc volcanoes situated on continental crust.

Groundwater flow, nutrient, and stable isotope dynamics in the parafluvial-hyporheic zone of the regulated Lower Colorado River (Texas, USA) over the course of a small flood

NASA Astrophysics Data System (ADS)

Briody, Alyse C.; Cardenas, M. Bayani; Shuai, Pin; Knappett, Peter S. K.; Bennett, Philip C.

2016-06-01

Periodic releases from an upstream dam cause rapid stage fluctuations in the Lower Colorado River near Austin, Texas, USA. These daily pulses modulate fluid exchange and residence times in the hyporheic zone where biogeochemical reactions are typically pronounced. The effects of a small flood pulse under low-flow conditions on surface-water/groundwater exchange and biogeochemical processes were studied by monitoring and sampling from two dense transects of wells perpendicular to the river. The first transect recorded water levels and the second transect was used for water sample collection at three depths. Samples were collected from 12 wells every 2 h over a 24-h period which had a 16-cm flood pulse. Analyses included nutrients, carbon, major ions, and stable isotopes of water. The relatively small flood pulse did not cause significant mixing in the parafluvial zone. Under these conditions, the river and groundwater were decoupled, showed potentially minimal mixing at the interface, and did not exhibit any discernible denitrification of river-borne nitrate. The chemical patterns observed in the parafluvial zone can be explained by evaporation of groundwater with little mixing with river water. Thus, large pulses may be necessary in order for substantial hyporheic mixing and exchange to occur. The large regulated river under a low-flow and small flood pulse regime functioned mainly as a gaining river with little hydrologic connectivity beyond a narrow hyporheic zone.

Observation of zone folding induced acoustic topological insulators and the role of spin-mixing defects

NASA Astrophysics Data System (ADS)

Deng, Yuanchen; Ge, Hao; Tian, Yuan; Lu, Minghui; Jing, Yun

2017-11-01

This article reports on the experimental realization of a flow-free, pseudospin-based acoustic topological insulator designed using the strategy of zone folding. Robust sound one-way propagation is demonstrated with the presence of non-spin-mixing defects. On the other hand, it is shown that spin-mixing defects, which break the geometric symmetry and therefore the pseudo-time-reversal symmetry, can open up nontrivial band gaps within the edge state frequency band, and their width can be tailored by the extent of the defect. This provides a possible route for realizing tunable acoustic topological insulators.

Complex cytogeographical patterns reveal a dynamic tetraploid–octoploid contact zone

PubMed Central

Castro, Mariana; Castro, Sílvia; Figueiredo, Albano; Husband, Brian; Loureiro, João

2018-01-01

Abstract The distribution of cytotypes in mixed-ploidy species is crucial for evaluating ecological processes involved in the establishment and evolution of polyploid taxa. Here, we use flow cytometry and chromosome counts to explore cytotype diversity and distributions within a tetraploid–octoploid contact zone. We then use niche modelling and ploidy seed screening to assess the roles of niche differentiation among cytotypes and reproductive interactions, respectively, in promoting cytotype coexistence. Two cytotypes, tetraploids and octoploids, were dominant within the contact zone. They were most often distributed parapatrically or allopatrically, resulting in high geographic isolation. Still, 16.7 % of localities comprised two or more cytotypes, including the intermediate hexaploid cytotype. Tetraploids and octoploids had high environmental niche overlap and associated with similar climatic environments, suggesting they have similar ecological requirements. Given the geographical separation and habitat similarity among cytotypes, mixed-ploidy populations may be transitional and subject to the forces of minority cytotype exclusion which lead to pure-ploidy populations. However, seed ploidy analysis suggests that strong reproductive barriers may enforce assortative mating which favours stable cytotype coexistence. High cytogenetic diversity detected in the field suggests that unreduced gamete formation and hybridization events seem frequent in the studied polyploid complex and might be involved with the recurrent polyploid formation, governing, as well, the gene flow between cytogenetic entities. PMID:29593853

Complex cytogeographical patterns reveal a dynamic tetraploid-octoploid contact zone.

PubMed

Castro, Mariana; Castro, Sílvia; Figueiredo, Albano; Husband, Brian; Loureiro, João

2018-03-01

The distribution of cytotypes in mixed-ploidy species is crucial for evaluating ecological processes involved in the establishment and evolution of polyploid taxa. Here, we use flow cytometry and chromosome counts to explore cytotype diversity and distributions within a tetraploid-octoploid contact zone. We then use niche modelling and ploidy seed screening to assess the roles of niche differentiation among cytotypes and reproductive interactions, respectively, in promoting cytotype coexistence. Two cytotypes, tetraploids and octoploids, were dominant within the contact zone. They were most often distributed parapatrically or allopatrically, resulting in high geographic isolation. Still, 16.7 % of localities comprised two or more cytotypes, including the intermediate hexaploid cytotype. Tetraploids and octoploids had high environmental niche overlap and associated with similar climatic environments, suggesting they have similar ecological requirements. Given the geographical separation and habitat similarity among cytotypes, mixed-ploidy populations may be transitional and subject to the forces of minority cytotype exclusion which lead to pure-ploidy populations. However, seed ploidy analysis suggests that strong reproductive barriers may enforce assortative mating which favours stable cytotype coexistence. High cytogenetic diversity detected in the field suggests that unreduced gamete formation and hybridization events seem frequent in the studied polyploid complex and might be involved with the recurrent polyploid formation, governing, as well, the gene flow between cytogenetic entities.

A micro-kinematic framework for vorticity analysis in polyphase shear zones using integrated field, microstructural and crystallographic orientation-dispersion methods

NASA Astrophysics Data System (ADS)

Kruckenberg, S. C.; Michels, Z. D.; Parsons, M. M.

2017-12-01

We present results from integrated field, microstructural and textural analysis in the Burlington mylonite zone (BMZ) of eastern Massachusetts to establish a unified micro-kinematic framework for vorticity analysis in polyphase shear zones. Specifically, we define the vorticity-normal surface based on lattice-scale rotation axes calculated from electron backscatter diffraction data using orientation statistics. In doing so, we objectively identify a suitable reference frame for rigid grain methods of vorticity analysis that can be used in concert with textural studies to constrain field- to plate-scale deformation geometries without assumptions that may bias tectonic interpretations, such as relationships between kinematic axes and fabric forming elements or the nature of the deforming zone (e.g., monoclinic vs. triclinic shear zones). Rocks within the BMZ comprise a heterogeneous mix of quartzofeldspathic ± hornblende-bearing mylonitic gneisses and quartzites. Vorticity axes inferred from lattice rotations lie within the plane of mylonitic foliation perpendicular to lineation - a pattern consistent with monoclinic deformation geometries involving simple shear and/or wrench-dominated transpression. The kinematic vorticity number (Wk) is calculated using Rigid Grain Net analysis and ranges from 0.25-0.55, indicating dominant general shear. Using the calculated Wk values and the dominant geographic fabric orientation, we constrain the angle of paleotectonic convergence between the Nashoba and Avalon terranes to 56-75º with the convergence vector trending 142-160° and plunging 3-10°. Application of the quartz recrystallized grain size piezometer suggests differential stresses in the BMZ mylonites ranging from 44 to 92 MPa; quartz CPO patterns are consistent with deformation at greenschist- to amphibolite-facies conditions. We conclude that crustal strain localization in the BMZ involved a combination of pure and simple shear in a sinistral reverse transpressional shear zone formed at or near the brittle-ductile transition under relatively high stress conditions. Moreover, we demonstrate the utility of combined crystallographic and rigid grain methods of vorticity analysis for deducing deformation geometries, kinematics, and tectonic histories in polyphase shear zones.

Colloid formation and metal transport through two mixing zones affected by acid mine drainage near Silverton, Colorado

USGS Publications Warehouse

Schemel, L.E.; Kimball, B.A.; Bencala, K.E.

2000-01-01

Stream discharges and concentrations of dissolved and colloidal metals (Al, Ca, Cu, Fe, Mg, Mn, Pb, and Zn), SO4, and dissolved silica were measured to identify chemical transformations and determine mass transports through two mixing zones in the Animas River that receive the inflows from Cement and Mineral Creeks. The creeks were the dominant sources of Al, Cu, Fe, and Pb, whereas the upstream Animas River supplied about half of the Zn. With the exception of Fe, which was present in dissolved and colloidal forms, the metals were dissolved in the acidic, high-SO4 waters of Cement Creek (pH 3.8). Mixing of Cement Creek with the Animas River increased pH to near-neutral values and transformed Al and some additional Fe into colloids which also contained Cu and Pb. Aluminium and Fe colloids had already formed in the mildly acidic conditions in Mineral Creek (pH 6.6) upstream of the confluence with the Animas River. Colloidal Fe continued to form downstream of both mixing zones. The Fe- and Al-rich colloids were important for transport of Cu, Pb, and Zn, which appeared to have sorbed to them. Partitioning of Zn between dissolved and colloidal phases was dependent on pH and colloid concentration. Mass balances showed conservative transports for Ca, Mg, Mn, SO4, and dissolved silica through the two mixing zones and small losses (< 10%) of colloidal Al, Fe and Zn from the water column.

77 FR 50462 - Foreign-Trade Zone 59-Lincoln, NE, Notification of Proposed Production Activity; Novartis...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-21

... mixed medicines, including those containing penicillin, alkaloids, analgesics, antibiotics....; isradipine (USP); desiccant; croscarmellose sodium NF; microcellulose; bulk penicillin mixed medicines; bulk mixed drugs; including penicillins; antibiotics; hormones; and alkaloids; caffeine; dextrins and...

The public health roots of zoning: in search of active living's legal genealogy.

PubMed

Schilling, Joseph; Linton, Leslie S

2005-02-01

Improvements in the built environment and changes in land-use policy are promising approaches to increasing physical activity among a largely sedentary population. Opportunities for walking and cycling as part of daily life are important to increasing physical activity and improving health. Yet, local zoning codes and related land-use regulations have made it difficult to create vibrant, mixed-use neighborhoods with well-connected streets and more compact development-the infrastructure necessary to support healthier rates of walking and cycling for transportation. To better understand the dynamic nature of land-use law and policy, and how policymakers might accomplish zoning reform to encourage more physically active environments, this paper traces the public health roots of zoning through a family tree of land-use legal doctrines. Zoning and public health laws evolved from the same legal ancestors-the common law of public nuisance and the expansion of state police powers, both premised on protection of the public's health. When the U.S. Supreme Court approved zoning in the 1926 case of Ambler Realty v. Village of Euclid, it nominally recognized the health basis of zoning. But it went on to craft a new legal rationale focused more on protection of property rights and residential neighborhoods. Since Euclid, court decisions have given little consideration to the public health roots of zoning. Given an emerging body of research demonstrating the importance of walking-friendly environments and the deference shown by the courts to the passage of zoning laws, the courts are likely to support policymakers as they move to change zoning systems conceived long ago. Legal, historical, and policy rationales support the modernization of zoning and land use policies that allow sensible mixes of land uses. Mixed land uses make walking an attractive alternative to driving and support a more physically active and healthy citizenry.

Forest gradient response in Sierran landscapes: the physical template

USGS Publications Warehouse

Urban, Dean L.; Miller, Carol; Halpin, Patrick N.; Stephenson, Nathan L.

2000-01-01

Vegetation pattern on landscapes is the manifestation of physical gradients, biotic response to these gradients, and disturbances. Here we focus on the physical template as it governs the distribution of mixed-conifer forests in California's Sierra Nevada. We extended a forest simulation model to examine montane environmental gradients, emphasizing factors affecting the water balance in these summer-dry landscapes. The model simulates the soil moisture regime in terms of the interaction of water supply and demand: supply depends on precipitation and water storage, while evapotranspirational demand varies with solar radiation and temperature. The forest cover itself can affect the water balance via canopy interception and evapotranspiration. We simulated Sierran forests as slope facets, defined as gridded stands of homogeneous topographic exposure, and verified simulated gradient response against sample quadrats distributed across Sequoia National Park. We then performed a modified sensitivity analysis of abiotic factors governing the physical gradient. Importantly, the model's sensitivity to temperature, precipitation, and soil depth varies considerably over the physical template, particularly relative to elevation. The physical drivers of the water balance have characteristic spatial scales that differ by orders of magnitude. Across large spatial extents, temperature and precipitation as defined by elevation primarily govern the location of the mixed conifer zone. If the analysis is constrained to elevations within the mixed-conifer zone, local topography comes into play as it influences drainage. Soil depth varies considerably at all measured scales, and is especially dominant at fine (within-stand) scales. Physical site variables can influence soil moisture deficit either by affecting water supply or water demand; these effects have qualitatively different implications for forest response. These results have clear implications about purely inferential approaches to gradient analysis, and bear strongly on our ability to use correlative approaches in assessing the potential responses of montane forests to anthropogenic climatic change.

Earthquake Rupture at Focal Depth, Part I: Structure and Rupture of the Pretorius Fault, TauTona Mine, South Africa

NASA Astrophysics Data System (ADS)

Heesakkers, V.; Murphy, S.; Reches, Z.

2011-12-01

We analyze the structure of the Archaean Pretorius fault in TauTona mine, South Africa, as well as the rupture-zone that recently reactivated it. The analysis is part of the Natural Earthquake Laboratory in South African Mines (NELSAM) project that utilizes the access to 3.6 km depth provided by the mining operations. The Pretorius fault is a ~10 km long, oblique-strike-slip fault with displacement of up to 200 m that crosscuts fine to very coarse grain quartzitic rocks in TauTona mine. We identify here three structural zones within the fault-zone: (1) an outer damage zone, ~100 m wide, of brittle deformation manifested by multiple, widely spaced fractures and faults with slip up to 3 m; (2) an inner damage zone, 25-30 m wide, with high density of anastomosing conjugate sets of fault segments and fractures, many of which carry cataclasite zones; and (3) a dominant segment, with a cataclasite zone up to 50 cm thick that accommodated most of the Archaean slip of the Pretorius fault, and is regarded as the `principal slip zone' (PSZ). This fault-zone structure indicates that during its Archaean activity, the Pretorius fault entered the mature fault stage in which many slip events were localized along a single, PSZ. The mining operations continuously induce earthquakes, including the 2004, M2.2 event that rejuvenated the Pretorius fault in the NELSAM project area. Our analysis of the M2.2 rupture-zone shows that (1) slip occurred exclusively along four, pre-existing large, quasi-planer segments of the ancient fault-zone; (2) the slipping segments contain brittle cataclasite zones up to 0.5 m thick; (3) these segments are not parallel to each other; (4) gouge zones, 1-5 mm thick, composed of white `rock-flour' formed almost exclusively along the cataclasite-host rock contacts of the slipping segments; (5) locally, new, fresh fractures branched from the slipping segments and propagated in mixed shear-tensile mode; (6) the maximum observed shear displacement is 25 mm in oblique-normal slip. The mechanical analysis of this rupture-zone is presented in Part II (H eesakkers et al., Earthquake Rupture at Focal Depth, Part II: Mechanics of the 2004 M2.2 Earthquake Along the Pretorius Fault, TauTona mine, South Africa 2011, this volume).

Uncertainty analysis of accident notification time and emergency medical service response time in work zone traffic accidents.

PubMed

Meng, Qiang; Weng, Jinxian

2013-01-01

Taking into account the uncertainty caused by exogenous factors, the accident notification time (ANT) and emergency medical service (EMS) response time were modeled as 2 random variables following the lognormal distribution. Their mean values and standard deviations were respectively formulated as the functions of environmental variables including crash time, road type, weekend, holiday, light condition, weather, and work zone type. Work zone traffic accident data from the Fatality Analysis Report System between 2002 and 2009 were utilized to determine the distributions of the ANT and the EMS arrival time in the United States. A mixed logistic regression model, taking into account the uncertainty associated with the ANT and the EMS response time, was developed to estimate the risk of death. The results showed that the uncertainty of the ANT was primarily influenced by crash time and road type, whereas the uncertainty of EMS response time is greatly affected by road type, weather, and light conditions. In addition, work zone accidents occurring during a holiday and in poor light conditions were found to be statistically associated with a longer mean ANT and longer EMS response time. The results also show that shortening the ANT was a more effective approach in reducing the risk of death than the EMS response time in work zones. To shorten the ANT and the EMS response time, work zone activities are suggested to be undertaken during non-holidays, during the daytime, and in good weather and light conditions.

Validating Variance Similarity Functions in the Entrainment Zone

NASA Astrophysics Data System (ADS)

Osman, M.; Turner, D. D.; Heus, T.; Newsom, R. K.

2017-12-01

In previous work, the water vapor variance in the entrainment zone was proposed to be proportional to the convective velocity scale, gradient water vapor mixing ratio and the Brunt-Vaisala frequency in the interfacial layer, while the variance of the vertical wind at in the entrainment zone was defined in terms of the convective velocity scale. The variances in the entrainment zone have been hypothesized to depend on two distinct functions, which also depend on the Richardson number. To the best of our knowledge, these hypotheses have never been tested observationally. Simultaneous measurements of the Eddy correlation surface flux, wind shear profiles from wind profilers, and variance profile measurements of vertical motions and water vapor by Doppler and Raman lidars, respectively, provide a unique opportunity to thoroughly examine the functions used in defining the variances and validate them. These observations were made over the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site. We have identified about 30 cases from 2016 during which the convective boundary layer (CBL) is quasi-stationary and well mixed for at least 2 hours. The vertical profiles of turbulent fluctuations of the vertical wind and water vapor have been derived using an auto covariance technique to separate out the instrument random error to a set of 2-h period time series. The error analysis of the lidars observations demonstrates that the lidars are capable of resolving the vertical structure of turbulence around the entrainment zone. Therefore, utilizing this unique combination of observations, this study focuses on extensively testing the hypotheses that the second-order moments are indeed proportional to the functions which also depend on Richardson number. The coefficients that are used in defining the functions will also be determined observationally and compared against with the values suggested by Large eddy simulation (LES) studies.

Neighbourhood walkability, leisure-time and transport-related physical activity in a mixed urban-rural area.

PubMed

de Sa, Eric; Ardern, Chris I

2014-01-01

Objectives. To develop a walkability index specific to mixed rural/suburban areas, and to explore the relationship between walkability scores and leisure time physical activity. Methods. Respondents were geocoded with 500 m and 1,000 m buffer zones around each address. A walkability index was derived from intersections, residential density, and land-use mix according to built environment measures. Multivariable logistic regression models were used to quantify the association between the index and physical activity levels. Analyses used cross-sectional data from the 2007-2008 Canadian Community Health Survey (n = 1158; ≥18 y). Results. Respondents living in highly walkable 500 m buffer zones (upper quartiles of the walkability index) were more likely to walk or cycle for leisure than those living in low-walkable buffer zones (quartile 1). When a 1,000 m buffer zone was applied, respondents in more walkable neighbourhoods were more likely to walk or cycle for both leisure-time and transport-related purposes. Conclusion. Developing a walkability index can assist in exploring the associations between measures of the built environment and physical activity to prioritize neighborhood change.

Mixing with applications to inertial-confinement-fusion implosions

NASA Astrophysics Data System (ADS)

Rana, V.; Lim, H.; Melvin, J.; Glimm, J.; Cheng, B.; Sharp, D. H.

2017-01-01

Approximate one-dimensional (1D) as well as 2D and 3D simulations are playing an important supporting role in the design and analysis of future experiments at National Ignition Facility. This paper is mainly concerned with 1D simulations, used extensively in design and optimization. We couple a 1D buoyancy-drag mix model for the mixing zone edges with a 1D inertial confinement fusion simulation code. This analysis predicts that National Ignition Campaign (NIC) designs are located close to a performance cliff, so modeling errors, design features (fill tube and tent) and additional, unmodeled instabilities could lead to significant levels of mix. The performance cliff we identify is associated with multimode plastic ablator (CH) mix into the hot-spot deuterium and tritium (DT). The buoyancy-drag mix model is mode number independent and selects implicitly a range of maximum growth modes. Our main conclusion is that single effect instabilities are predicted not to lead to hot-spot mix, while combined mode mixing effects are predicted to affect hot-spot thermodynamics and possibly hot-spot mix. Combined with the stagnation Rayleigh-Taylor instability, we find the potential for mix effects in combination with the ice-to-gas DT boundary, numerical effects of Eulerian species CH concentration diffusion, and ablation-driven instabilities. With the help of a convenient package of plasma transport parameters developed here, we give an approximate determination of these quantities in the regime relevant to the NIC experiments, while ruling out a variety of mix possibilities. Plasma transport parameters affect the 1D buoyancy-drag mix model primarily through its phenomenological drag coefficient as well as the 1D hydro model to which the buoyancy-drag equation is coupled.

Mixing with applications to inertial-confinement-fusion implosions.

PubMed

Rana, V; Lim, H; Melvin, J; Glimm, J; Cheng, B; Sharp, D H

2017-01-01

Approximate one-dimensional (1D) as well as 2D and 3D simulations are playing an important supporting role in the design and analysis of future experiments at National Ignition Facility. This paper is mainly concerned with 1D simulations, used extensively in design and optimization. We couple a 1D buoyancy-drag mix model for the mixing zone edges with a 1D inertial confinement fusion simulation code. This analysis predicts that National Ignition Campaign (NIC) designs are located close to a performance cliff, so modeling errors, design features (fill tube and tent) and additional, unmodeled instabilities could lead to significant levels of mix. The performance cliff we identify is associated with multimode plastic ablator (CH) mix into the hot-spot deuterium and tritium (DT). The buoyancy-drag mix model is mode number independent and selects implicitly a range of maximum growth modes. Our main conclusion is that single effect instabilities are predicted not to lead to hot-spot mix, while combined mode mixing effects are predicted to affect hot-spot thermodynamics and possibly hot-spot mix. Combined with the stagnation Rayleigh-Taylor instability, we find the potential for mix effects in combination with the ice-to-gas DT boundary, numerical effects of Eulerian species CH concentration diffusion, and ablation-driven instabilities. With the help of a convenient package of plasma transport parameters developed here, we give an approximate determination of these quantities in the regime relevant to the NIC experiments, while ruling out a variety of mix possibilities. Plasma transport parameters affect the 1D buoyancy-drag mix model primarily through its phenomenological drag coefficient as well as the 1D hydro model to which the buoyancy-drag equation is coupled.

Semidiurnal temperature changes caused by tidal front movements in the warm season in seabed habitats on the Georges Bank northern margin and their ecological implications

USGS Publications Warehouse

Guida, Vincent G.; Valentine, Page C.; Gallea, Leslie B.

2013-01-01

Georges Bank is a large, shallow feature separating the Gulf of Maine from the Atlantic Ocean. Previous studies demonstrated a strong tidal-mixing front during the warm season on the northern bank margin between thermally stratified water in the Gulf of Maine and mixed water on the bank. Tides transport warm water off the bank during flood tide and cool gulf water onto the bank during ebb tide. During 10 days in August 2009, we mapped frontal temperatures in five study areas along ∼100 km of the bank margin. The seabed “frontal zone”, where temperature changed with frontal movment, experienced semidiurnal temperature maxima and minima. The tidal excursion of the frontal boundary between stratified and mixed water ranged 6 to 10 km. This “frontal boundary zone” was narrower than the frontal zone. Along transects perpendicular to the bank margin, seabed temperature change at individual sites ranged from 7.0°C in the frontal zone to 0.0°C in mixed bank water. At time series in frontal zone stations, changes during tidal cycles ranged from 1.2 to 6.1°C. The greatest rate of change (-2.48°C hr-1) occurred at mid-ebb. Geographic plots of seabed temperature change allowed the mapping of up to 8 subareas in each study area. The magnitude of temperature change in a subarea depended on its location in the frontal zone. Frontal movement had the greatest effect on seabed temperature in the 40 to 80 m depth interval. Subareas experiencing maximum temperature change in the frontal zone were not in the frontal boundary zone, but rather several km gulfward (off-bank) of the frontal boundary zone. These results provide a new ecological framework for examining the effect of tidally-driven temperature variability on the distribution, food resources, and reproductive success of benthic invertebrate and demersal fish species living in tidal front habitats.

Experimental constraints and theoretical bases for microstructural damage in plate boundary shear zones

NASA Astrophysics Data System (ADS)

Skemer, P. A.; Cross, A. J.; Bercovici, D.

2016-12-01

(Ultra)mylonites from plate boundary shear zones are characterized by severe grain-size reduction and well-mixed mineral phases. The evolution from relatively undeformed tectonite protoliths to highly deformed (ultra)mylonites via the formation of new grain and phase boundaries is described as microstructural `damage.' Microstructural damage is important for two reasons: grain-size reduction is thought to result in significant rheological weakening, while phase mixing inhibits mechanical recovery and preserves the zone of weakness to be reactivated repeatedly throughout the tectonic cycle. Grain-size reduction by dynamic recrystallization has been studied extensively in both geologic and engineered materials, yet the progressive mixing of mineral phases during high pressure/temperature shear - the other essential element of damage or mylonitization - is not well understood. In this contribution we present new experimental results and theory related to two distinct phase mixing processes. First, we describe high strain torsion experiments on calcite and anhydrite mixtures and a simple geometric mixing model related to the stretching and thinning of monophase domains. Second, we describe a grain-switching mechanism that is driven by the surface-tension driven migration of newly formed interphase triple junctions. Unlike dynamic recrystallization, which occurs at relatively small strains, both phase mixing mechanisms described here appear to require extremely large strains, a prediction that is consistent with geologic observations. These data suggest that ductile shear zones experience long, transient intervals of microstructural evolution during which rheology is not at steady state. Microstructural damage may be interpreted as the product of several interconnected physical processes, which are collectively essential to the preservation of long-lived, Earth-like plate tectonics.

Assessment of the environmental significance of nutrients and heavy metal pollution in the river network of Serbia.

PubMed

Dević, Gordana; Sakan, Sanja; Đorđević, Dragana

2016-01-01

In this paper, the data for ten water quality variables collected during 2009 at 75 monitoring sites along the river network of Serbia are considered. The results are alarming because 48% of the studied sites were contaminated by Ni, Mn, Pb, As, and nutrients, which are key factors impairing the water quality of the rivers in Serbia. Special attention should be paid to Zn and Cu, listed in the priority toxic pollutants of US EPA for aquatic life protection. The employed Q-model cluster analysis grouped the data into three major pollution zones (low, moderate, and high). Most sites classified as "low pollution zones" (LP) were in the main rivers, whereas those classified as "moderate and high pollution zones" (MP and HP, respectively) were in the large and small tributaries/hydro-system. Principal component analysis/factor analysis (PCA/FA) showed that the dissolved metals and nutrients in the Serbian rivers varied depending on the river, the heterogeneity of the anthropogenic activities in the basins (influenced primarily by industrial wastewater, agricultural activities, and urban runoff pollution), and natural environmental variability, such as geological characteristics. In LP dominated non-point source pollution, such as agricultural and urban runoff, whereas mixed source pollution dominated in the MP and HP zones. These results provide information to be used for developing better pollution control strategies for the river network of Serbia.

On the parameterization of interleaving and turbulent mixing using CTD data from the Azores Frontal Zone

NASA Astrophysics Data System (ADS)

Kuzmina, N. P.

2000-01-01

CTD-data obtained in the Azores Frontal Zone using a towed undulating vehicle are analyzed to study the relationship between characteristics of intrusions and mean parameters of the thermohaline field. A self-similar dependence between intrusion intensity and hydrological parameters is obtained. The most well-founded interpretation of the empirical dependence is as follows: (a) the main source supporting intrusive layering is the salt finger convection; (b) the abrupt decrease of intrusion intensity with the reduction of geostrophic Richardson number obtained from the analysis is explained by the beginning of turbulence when salt fingers do not work any longer, so the "driving force" for intrusive motion disappears. These results are consistent with the conclusions of the paper [Kuzmina N.P., Rodionov V.B., 1992. About the influence of baroclinicity upon generation of the thermohaline intrusions in the oceanic frontal zones. Izvestiya Akad. Nauk SSSR, Atmosperic and Oceanic Physics 28 (10-11), 1077-1086]. These conclusions imply that there are three main mechanisms of intrusive layering at oceanic fronts, namely the 2D baroclinic instability of geostrophic flow, the vertical shear instability and the thermohaline instability where the driving source of intrusive motion is double diffusive convection. The baroclinic and thermohaline instabilities can generate intrusions of large vertical scale, while vertical shear instability usually gives rise to thin turbulent layers. Turbulence in these thin layers can prevent salt finger convection and thus destroy the energy source of the intrusive motion conditioned by thermoclinicity. Therefore, the baroclinicity plays two parts in the processes of the intrusive layering: (1) it prevents double-diffusion interleaving by means of turbulence, and (2) it generates intrusions due to the 2D baroclinic instability of geostrophic current. Using features of thermohaline interleaving as a specific tracer of turbulent mixing, we have estimated turbulent mixing coefficient as k t˜ Ri-0.8 ( Ri>1), where Ri is the geostrophic Richardson number. Application of the proposed approach to other frontal zones is discussed.

AmeriFlux US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is a pine/fir forest; it historically experienced logging and wildfire, was thinned in ~2012, and experienced severe drought and ~20% canopy mortality in 2011-15.

A new unsteady mixing model to predict NO(x) production during rapid mixing in a dual-stage combustor

NASA Technical Reports Server (NTRS)

Menon, Suresh

1992-01-01

An advanced gas turbine engine to power supersonic transport aircraft is currently under study. In addition to high combustion efficiency requirements, environmental concerns have placed stringent restrictions on the pollutant emissions from these engines. A combustor design with the potential for minimizing pollutants such as NO(x) emissions is undergoing experimental evaluation. A major technical issue in the design of this combustor is how to rapidly mix the hot, fuel-rich primary zone product with the secondary diluent air to obtain a fuel-lean mixture for combustion in the second stage. Numerical predictions using steady-state methods cannot account for the unsteady phenomena in the mixing region. Therefore, to evaluate the effect of unsteady mixing and combustion processes, a novel unsteady mixing model is demonstrated here. This model has been used to study multispecies mixing as well as propane-air and hydrogen-air jet nonpremixed flames, and has been used to predict NO(x) production in the mixing region. Comparison with available experimental data show good agreement, thereby providing validation of the mixing model. With this demonstration, this mixing model is ready to be implemented in conjunction with steady-state prediction methods and provide an improved engineering design analysis tool.

Structure of turbulent non-premixed flames modeled with two-step chemistry

NASA Technical Reports Server (NTRS)

Chen, J. H.; Mahalingam, S.; Puri, I. K.; Vervisch, L.

1992-01-01

Direct numerical simulations of turbulent diffusion flames modeled with finite-rate, two-step chemistry, A + B yields I, A + I yields P, were carried out. A detailed analysis of the turbulent flame structure reveals the complex nature of the penetration of various reactive species across two reaction zones in mixture fraction space. Due to this two zone structure, these flames were found to be robust, resisting extinction over the parameter ranges investigated. As in single-step computations, mixture fraction dissipation rate and the mixture fraction were found to be statistically correlated. Simulations involving unequal molecular diffusivities suggest that the small scale mixing process and, hence, the turbulent flame structure is sensitive to the Schmidt number.

Microstructure and Plastic Deformation of the As-Welded Invar Fusion Zones

NASA Astrophysics Data System (ADS)

Yao, D. J.; Zhou, D. R.; Xu, P. Q.; Lu, F. G.

2017-05-01

The as-welded Invar fusion zones were fabricated between cemented carbides and carbon steel using a Fe-Ni Invar interlayer and laser welding method. Three regions in the as-welded Invar fusion zones were defined to compare microstructures, and these were characterized and confirmed by scanning electron microscopy and X-ray diffractometry. The structure and plastic deformation mechanism for initial Invar Fe-Ni alloys and the as-welded Invar fusion zones are discussed. (1) After undergoing high-temperature thermal cycles, the microstructure of the as-welded Invar fusion zones contains γ-(Fe, Ni) solid solution (nickel dissolving in γ-Fe) with a face-centered cubic (fcc) crystal structure and mixed carbides (eutectic colonies, mixed carbides between two adjacent grains). The mixed carbides exhibited larger, coarser eutectic microstructures with a decrease in welding speed and an increase in heat input. (2) The structure of the initial Invar and the as-welded Invar is face-centered cubic γ-(Fe, Ni). (3) The as-welded Invar has a larger plastic deformation than initial Invar with an increase in local strain field and dislocation density. Slip deformation is propagated along the (111) plane. This finding helps us to understand microstructure and the formation of dislocation and plastic deformation when the Invar Fe-Ni alloy undergoes a high-temperature process.

Scheduling work zones in multi-modal networks phase 1: scheduling work zones in transportation service networks.

DOT National Transportation Integrated Search

2016-06-01

The purpose of this project is to study the optimal scheduling of work zones so that they have minimum negative impact (e.g., travel delay, gas consumption, accidents, etc.) on transport service vehicle flows. In this project, a mixed integer linear ...

Lenalidomide And Rituximab as Maintenance Therapy in Treating Patients With B-Cell Non-Hodgkin Lymphoma

ClinicalTrials.gov

2015-11-25

Adult Non-Hodgkin Lymphoma; Adult Grade III Lymphomatoid Granulomatosis; Contiguous Stage II Adult Burkitt Lymphoma; Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Contiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Contiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Contiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Contiguous Stage II Adult Lymphoblastic Lymphoma; Contiguous Stage II Grade 1 Follicular Lymphoma; Contiguous Stage II Grade 2 Follicular Lymphoma; Contiguous Stage II Grade 3 Follicular Lymphoma; Contiguous Stage II Mantle Cell Lymphoma; Contiguous Stage II Marginal Zone Lymphoma; Contiguous Stage II Small Lymphocytic Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Burkitt Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Adult Lymphoblastic Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma; Stage I Adult Burkitt Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Mixed Cell Lymphoma; Stage I Adult Diffuse Small Cleaved Cell Lymphoma; Stage I Adult Immunoblastic Large Cell Lymphoma; Stage I Adult Lymphoblastic Lymphoma; Stage I Grade 1 Follicular Lymphoma; Stage I Grade 2 Follicular Lymphoma; Stage I Grade 3 Follicular Lymphoma; Stage I Mantle Cell Lymphoma; Stage I Marginal Zone Lymphoma; Stage I Small Lymphocytic Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma; Waldenstrom Macroglobulinemia

Large-scale Atmospheric Transport Processes

NASA Technical Reports Server (NTRS)

Plumb, R. Alan

2004-01-01

Continuing earlier work, we continued an investigation of the seasonal behavior of the edges of the stratospheric surf zone. These edges form a barrier between the rapidly mixed surf zone and the relatively isolated tropics. In collaboration with Dr Lynn Sparling at GSFC, we used a statistical analysis of HALOE and CLAES trace gas data from UARS to identify and locate these edges during each UARS observing period. We found that the edges on both sides of the equator are present all year (a fact that is important for conceptual models of stratospheric transport), though that on the summer side of the equator is much less sharp than the winter edge. The edges migrate seasonally into the summer hemisphere. Their location also shows influence of the QBO, together with the SAO at higher altitudes. Comparisons with effective diffusivities, and the edge locations, suggest that the edge is sustained by surf zone entrainment during winter, but by the residual circulation during summer.

Stable isotopic fingerprint of a hyporheic-hypolentic boundary in a reservoir

NASA Astrophysics Data System (ADS)

Aseltyne, Todd A.; Rowe, Harold D.; Fryar, Alan E.

2006-12-01

Stable isotopes of H2O are used to define the hyporheic-hypolentic boundary in Ledbetter Creek as it discharges to Kentucky Lake, a constructed reservoir in western Kentucky, USA. High-resolution (centimeter-scale) sample collection and analysis were utilized to determine one-dimensional variations in δ2H and δ18O of H2O and chloride (Cl-) across the boundary. During reservoir low stand in winter, the hyporheic-hypolentic zone contains water from Ledbetter Creek and groundwater separated by an interface at ~10 cm below the channel bottom. Following reservoir-stage increase in spring and summer, water from Kentucky Lake infiltrates into the hyporheic-hypolentic zone to a depth of at least 18 cm below the channel bottom. Reservoir-stage decline in autumn causes source-water mixing, largely obscuring the hyporheic-hypolentic boundary. Stable isotopes provide an effective complement to conventional tracers for delineation of water masses within the hyporheic-hypolentic zone.

Nitrate in groundwater and water sources used by riparian trees in an agricultural watershed: A chemical and isotopic investigation in southern Minnesota

USGS Publications Warehouse

Komor, Stephen C.; Magner, Joseph A.

1996-01-01

This study evaluates processes that affect nitrate concentrations in groundwater beneath riparian zones in an agricultural watershed. Nitrate pathways in the upper 2 m of groundwater were investigated beneath wooded and grass-shrub riparian zones next to cultivated fields. Because trees can be important components of the overall nitrate pathway in wooded riparian zones, water sources used by riparian trees and possible effects of trees on nitrate concentrations in groundwater were also investigated. Average nitrate concentrations in shallow groundwater beneath the cultivated fields were 5.5 mg/L upgradient of the wooded riparian zone and 3.5 mg/L upgradient of the grass-shrub zone. Shallow groundwater beneath the fields passed through the riparian zones and discharged into streams that had average nitrate concentrations of 8.5 mg/L (as N). Lateral variations of δD values in groundwater showed that mixing among different water sources occurred beneath the riparian zones. In the wooded riparian zone, nitrate concentrations in shallow groundwater were diluted by upwelling, nitrate-poor, deep groundwater. Upwelling deep groundwater contained ammonium with a δ15N of 5‰ that upon nitrification and mixing with nitrate in shallow groundwater caused nitrate δ15N values in shallow groundwater to decrease by as much as 19.5‰. Stream water penetrated laterally beneath the wooded riparian zone as far as 19 m from the stream's edge and beneath the grass-shrub zone as far as 27 m from the stream's edge. Nitrate concentrations in shallow groundwater immediately upgradient of where it mixed with stream water averaged 0.4 mg/L in the wooded riparian zone and 0.8 mg/L near the grass-shrub riparian zone. Nitrate concentrations increased toward the streams because of mixing with nitrate-rich stream water. Because nitrate concentrations were larger in stream water than shallow groundwater, concentrated nitrate in the streams cannot have come from shallow groundwater at these sites. Water sources of riparian trees were identified by comparing δD values of sap water, soil water, groundwater, and stream water. Soil water was the main water source for trees in the outer 4 to 6 m of one part of the wooded riparian zone and outer 10 m of another part. Groundwater was a significant water source for trees closer to the streams where the water table was less than about 2.1 to 2.7 m below the surface. No evidence was found in the nitrate concentration profiles that trees close to the streams that took up groundwater through their roots also took up nitrate from groundwater. The lack of such evidence is attributed to the nitrate concentration profiles being insufficiently sensitive indicators of nitrate removal by trees.

What controls landward vergence of the accretionary prism offshore northern Sumatra?

NASA Astrophysics Data System (ADS)

Frederik, M. C. G.; Gulick, S. P. S.; Austin, J. A., Jr.; Bangs, N. L.; Udrekh, U.

2014-12-01

The accretionary prism offshore northern Sumatra consists of steep outer slopes (5-12°), and a plateau ~100-120 km wide comprised of anticlinal folds of 2-16 km wavelength seaward of a steep slope adjacent to the Aceh (forearc) Basin. Our study area, 1-7°N and 92-97°E, covers the entire forearc from northwest of Aceh to west of Simeulue Island. Five 2D MCS seismic profiles transecting the prism from the Sunda Trench to the Aceh Basin, along with multibeam data, have been used to investigate wedge morphology and structure. Analysis of fold vergence along the profiles and areal classification of the predominant vergence reveal three structural zones: 1) predominantly landward-vergent folds near the Sunda Trench, 2) predominantly seaward-vergent folds near the Aceh Basin, and 3) mixed vergent folds between those two zones. Extensive landward vergence is uncommon in accretionary prisms worldwide. One explanation is the existence of a backstop with a seaward dipping edge, such that overlying younger sediments accreted to the prism form landward-vergent folds. We propose a backstop geometry that extends from under the Aceh Basin to under the mixed vergence zone, based on the observed structural zones and published velocity models of this margin. The backstop may consist either of older accreted sediment or the granitic Sunda Block. With the existence of a strong inner wedge acting as a backstop, together with suspected indurated sediments forming the landward vergence zone, rupture during major subduction zone earthquakes nucleating under the forearc basin or central plateau high can propagate farther seaward toward the Sunda Trench and displace greater volumes of water than a more landward rupture, yielding more hazardous tsunami. Using bathymetric data of before and after the 2004 earthquake, we are now testing the hypothesis that maximum slip occurs near the trench. These results will be presented.

Mixed-use development in a high-rise context

NASA Astrophysics Data System (ADS)

Generalova, Elena M.; Generalov, Viktor P.; Kuznetsova, Anna A.; Bobkova, Oksana N.

2018-03-01

The article deals with an actual problem of finding techniques and methods to create a comfortable urban environment. The authors emphasize that in the existing conditions of intensive urban development greater attention should be given to spatial concentration based on and more compact distribution of population in urban space. It is stressed that including mixed-use facilities into urban realm results in a significant improvement of living environment qualitative characteristics. The paper also examines modern approaches to constructing a «compact city» for comfortable and convenient living with a mixed-use tall building development. The authors explore the world's experience of designing tall mixed-use buildings and reveal modern trends in their construction. The statistics given is based on the data analysis of a group of tall mixed-use buildings consisting of more than 400 objects, constructed in 2007-2016. The research shows functional and architectural peculiarities of this typology of tall buildings and investigates a mechanism of creating zones of mixed-use tall building development in the urban structure. In conclusion, the authors consider prospects of development and major directions of improvement of mixed-use tall building parameters for a reasonable territorial urban growth and creation of high-density and comfortable building development.

Preparation, spectroscopic characterization and antimicrobial activities of mixed metal (Sb and Bi) bridged derivatives with mixed sulfur donor ligands

NASA Astrophysics Data System (ADS)

Joshi, Sapana; Chauhan, H. P. S.; Carpenter, Nitin

2017-01-01

This article explores the syntheses of six mixed metal derivatives of antimony(III) and bismuth(III) by the reaction of ethane-1,2-dithiol and metal bis derivatives of dithiocarbamates and/or dithiophosphates ligands in 1:1:1 M stoichiometry. These derivatives have been characterized by physicochemical [elemental analysis (C, H, N, S, Sb and Bi), molecular weight and melting point determinations], spectral [UV-Visible, FTIR, NMR (1H, 13C and 31P)], powder X-ray diffraction studies. These derivatives have nano-ranged crystallite size (8.18-18.04 nm) with monoclinic crystal system. All the synthesized derivatives have two metal centers (Sb and Bi) which elevate the zone of inhibition against four bacterial and two fungal species as compared to single metal species (metal precursors) as well as standard drugs.

Wave Climate and Wave Mixing in the Marginal Ice Zones of Arctic Seas, Observations and Modelling

DTIC Science & Technology

2014-09-30

At the same time, the PIs participate in Australian efforts of developing wave-ocean- ice coupled models for Antarctica . Specific new physics modules...Wave Mixing in the Marginal Ice Zones of Arctic Seas, Observations and Modelling Alexander V. Babanin Swinburne University of Technology, PO Box...operational forecast. Altimeter climatology and the wave models will be used to study the current and future wind/wave and ice trends. APPROACH

Evaluation of Superpave Gyratory Compaction of Hot Mix Asphalt

DOT National Transportation Integrated Search

1988-01-01

About 85 percent of hot mix asphalt (HMA) by volume consist of mineral aggregate. One of the most important properties of the aggregate in a HMA mix is the gradation. This study was carried out to evaluate the effect of restricted zone on volumetric ...

Descriptions of the Animas River-Cement Creek confluence and mixing zone near Silverton, Colorado, during the late summers of 1996 and 1997

USGS Publications Warehouse

Schemel, Laurence E.; Cox, Marisa H.

2005-01-01

Acidic waters from Cement Creek discharge into the circum-neutral Animas River in a high-elevation region of the San Juan Mountains near Silverton, Colorado. Cement Creek is acidic and enriched in metals and sulfate because it is fed by discharges from abandoned mines and natural mineral deposits. Mixing with the Animas River raises the pH and produces precipitates of iron and aluminum (oxy)hydroxides, which in turn can adsorb other metals. This confluence was studied in 1996 and 1997 to better understand mixing and sorption processes which are common during the neutralization of acidic streams. The photographs in this report show flow braiding and other features that influenced the way the two streams mixed during the late summers of the two years. They also show 'banding' due to incomplete mixing and 'opalescence' due to chemical reactions and the formation of colloidal-size particles in the mixing zone.

Centrifugal contactor with liquid mixing and flow control vanes and method of mixing liquids of different phases

DOEpatents

Jubin, Robert T.; Randolph, John D.

1991-01-01

The invention is directed to a centrifugal contactor for solvent extraction systems. The centrifugal contactor is provided with an annular vertically oriented mixing chamber between the rotor housing and the rotor for mixing process liquids such as the aqueous and organic phases of the solvent extraction process used for nuclear fuel reprocessing. A set of stationary helically disposed vanes carried by the housing is in the lower region of the mixing chamber at a location below the process-liquid inlets for the purpose of urging the liquids in an upward direction toward the inlets and enhancing the mixing of the liquids and mass transfer between the liquids. The upper region of the mixing vessel above the inlets for the process liquids is also provided with a set helically disposed vanes carried by the housing for urging the process liquids in a downward direction when the liquid flow rates through the inlets are relatively high and the liquids contact the vane set in the upper region. The use of these opposing vane sets in the mixing zone maintains the liquid in the mixing zone at suitable levels.

Statistical characterization of planar two-dimensional Rayleigh-Taylor mixing layers

NASA Astrophysics Data System (ADS)

Sendersky, Dmitry

2000-10-01

The statistical evolution of a planar, randomly perturbed fluid interface subject to Rayleigh-Taylor instability is explored through numerical simulation in two space dimensions. The data set, generated by the front-tracking code FronTier, is highly resolved and covers a large ensemble of initial perturbations, allowing a more refined analysis of closure issues pertinent to the stochastic modeling of chaotic fluid mixing. We closely approach a two-fold convergence of the mean two-phase flow: convergence of the numerical solution under computational mesh refinement, and statistical convergence under increasing ensemble size. Quantities that appear in the two-phase averaged Euler equations are computed directly and analyzed for numerical and statistical convergence. Bulk averages show a high degree of convergence, while interfacial averages are convergent only in the outer portions of the mixing zone, where there is a coherent array of bubble and spike tips. Comparison with the familiar bubble/spike penetration law h = alphaAgt 2 is complicated by the lack of scale invariance, inability to carry the simulations to late time, the increasing Mach numbers of the bubble/spike tips, and sensitivity to the method of data analysis. Finally, we use the simulation data to analyze some constitutive properties of the mixing process.

Building application of solar energy. Study no. 2: Representative buildings for solar energy performance analysis and market penetration

NASA Technical Reports Server (NTRS)

Hirshberg, A. S.

1975-01-01

The following topics are discussed: (1) Assignment of population to microclimatic zones; (2) specifications of the mix of buildings in the SCE territory; (3) specification of four typical buildings for thermal analysis and market penetration studies; (4) identification of the materials and energy conserving characteristics of these typical buildings; (5) specifications of the HVAC functions used in each typical building, and determination of the HVAC systems used in each building; and (6) identification of the type of fuel used in each building.

Revised interpretations of stable C and O patterns in carbonate rocks resulting from meteoric diagenesis

NASA Astrophysics Data System (ADS)

Swart, Peter K.; Oehlert, Amanda M.

2018-02-01

A positive correlation between the δ13C and δ18O values of carbonate rocks is a screening tool widely used to identify the overprint of meteoric diagenesis on the original isotopic composition of a sample. In particular, it has been suggested that systematic change from negative to positive δ13C and δ18O values with increasing depth in the core is an indicator of alteration within the zone of mixing between meteoric and marine waters. In this paper, we propose that such covariance is not generated within the traditionally defined mixing zone, and that positive correlations between δ13C and δ18O values in marine carbonates are not necessarily indicators of meteoric alteration. This new interpretation is based on data collected from the shallow sub-surface of the Bahamas, a region unequivocally influenced by meteoric waters to depths of at least 200 m below the current sediment-water interface. The classic interpretation of the diagenetic environments, based on changes in the δ13C and δ18O values, would suggest the maximum penetration of freshwater occurs between 65 and 100 m below seafloor. Below these depths, a strong positive covariation between the δ13C and δ18O values exists, and would traditionally be defined as the mixing zone. However, based upon known changes in sea level, the penetration of the freshwater lens extends significantly below this limit. We contend that the zone showing covariance of δ13C and δ18O values is actually altered within the freshwater lens, and not the mixing zone as previously proposed. The co-varying trend in δ13C and δ18O values is the result of diagenetic processes occurring at the interface between vadose and phreatic zones. Significantly greater rates of recrystallization and neomorphism are driven by the increased rates of oxidation of organic matter at this transition with progressively less alteration occurring with increasing depth. As sea level oscillates, the position of this interface moves through the deposit, causing cumulative alteration throughout the section. Hence, we propose that the covariation between δ13C and δ18O values is a consequence of varying degrees of alteration, rather than the result of diagenesis occurring within the zone where marine and freshwater fluids mix. Furthermore, within the pervasively altered vadose zone, there is little correlation between δ13C and δ18O values, and therefore covariation between δ13C and δ18O values is not an unequivocal indicator of meteoric diagenesis.

Vaporization and Zonal Mixing in Performance Modeling of Advanced LOX-Methane Rockets

NASA Technical Reports Server (NTRS)

Williams, George J., Jr.; Stiegemeier, Benjamin R.

2013-01-01

Initial modeling of LOX-Methane reaction control (RCE) 100 lbf thrusters and larger, 5500 lbf thrusters with the TDK/VIPER code has shown good agreement with sea-level and altitude test data. However, the vaporization and zonal mixing upstream of the compressible flow stage of the models leveraged empirical trends to match the sea-level data. This was necessary in part because the codes are designed primarily to handle the compressible part of the flow (i.e. contraction through expansion) and in part because there was limited data on the thrusters themselves on which to base a rigorous model. A more rigorous model has been developed which includes detailed vaporization trends based on element type and geometry, radial variations in mixture ratio within each of the "zones" associated with elements and not just between zones of different element types, and, to the extent possible, updated kinetic rates. The Spray Combustion Analysis Program (SCAP) was leveraged to support assumptions in the vaporization trends. Data of both thrusters is revisited and the model maintains a good predictive capability while addressing some of the major limitations of the previous version.

Forging the Link: Using a Conservative Mixing Framework to Characterize Connections between Rivers and Great Lakes in River-lake Transition Zones

EPA Science Inventory

River-to-Great Lake transition zones are hydrologically, biogeochemically and biologically dynamic areas that regulate nutrient and energy fluxes between rivers and Great Lakes. Our goal is to characterize the biogeochemical properties of the river-lake transition zones and under...

Temporal and vertical distributions of bacterioplankton at the Gray's Reef National Marine Sanctuary.

PubMed

Lu, Xinxin; Sun, Shulei; Zhang, Yu-Qin; Hollibaugh, James T; Mou, Xiaozhen

2015-02-01

Large spatial scales and long-term shifts of bacterial community composition (BCC) in the open ocean can often be reliably predicted based on the dynamics of physical-chemical variables. The power of abiotic factors in shaping BCC on shorter time scales in shallow estuarine mixing zones is less clear. We examined the diurnal variation in BCC at different water depths in the spring and fall of 2011 at a station in the Gray's Reef National Marine Sanctuary (GRNMS). This site is located in the transition zone between the estuarine plume and continental shelf waters of the South Atlantic Bight. A total of 234,516 pyrotag sequences of bacterial 16S rRNA genes were recovered; they were taxonomically affiliated with >200 families of 23 bacterial phyla. Nonmetric multidimensional scaling analysis revealed significant differences in BCC between spring and fall samples, likely due to seasonality in the concentrations of dissolved organic carbon and nitrate plus nitrite. Within each diurnal sampling, BCC differed significantly by depth only in the spring and differed significantly between day and night only in the fall. The former variation largely tracked changes in light availability, while the latter was most correlated with concentrations of polyamines and chlorophyll a. Our results suggest that at the GRNMS, a coastal mixing zone, diurnal variation in BCC is attributable to the mixing of local and imported bacterioplankton rather than to bacterial growth in response to environmental changes. Our results also indicate that, like members of the Roseobacter clade, SAR11 bacteria may play an important role in processing dissolved organic material in coastal oceans. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

DYNAMIC MIXING MODEL OF THE CHIGNAHUAPAN THERMAL SPRING IN THE GEOTHERMAL ZONE OF THE ACOCULCO CALDERA, PUEBLA, MEXICO

NASA Astrophysics Data System (ADS)

Gutierrez-Cirlos, A.; Torres-Rodriguez, V.

2009-12-01

The Acoculco Caldera, of Pliocenic age, is located within the limits of the Transmexican Volcanic Belt (CVT) and the Sierra Madre Oriental (SMOr). The Acoculco geothermal zone consists of a 790m thick igneous sequence, related to a volcanic complex formed by andesites and rhyolitic domes emplaced in an 18 Km diameter annular fracture. It unconformably overlies a 5000 m thick section of folded and faulted Jurassic-Cretaceous carbonate rocks. The Chignahuapan Spring, located in the extreme eastern part of the Geothermal Zone of the Acoculco Caldera, yields temperatures of 49°C and discharges an estimated of 98 lps from the karstified Lower Cretaceous limestone. Both major and trace element geochemical analysis were carried out, and results were interpreted using Piper and Stiff diagrams, as well as geothermometry. The results indicate that water belongs to the calcium-bicarbonate type and yield temperatures in a range of 70-80°C at depth, which suggest an extensive lateral flow from the main reservoir and mixing with shallow groundwaters. The spring suffers significant variations in its temperature throughout the year, especially during the rainy season, when water temperature decreases up to 10°C. Analyzing the hot spring water temperature data from of the last 10 years and comparing it with the precipitation and air temperature curves of the region, we expect to develop a dynamic mixing model which depicts the relation between these factors and the importance of each one in the water temperature variation. We also look forward to be able to forecast water temperature trends for the next several years and correlate it with climate change in the area.

The interplay between crystallization, replenishment and hybridization in large felsic magma chambers

NASA Astrophysics Data System (ADS)

Bateman, R.

1995-09-01

While hybridized granitoid magmas are readily identifiable, the mechanisms of hybridization in large crustal magma chambers are so not clearly understood. Characteristic features of hybrid granitoids are (1) both the granitoid and included enclaves are commonly hybrids, as shown by mineralogy, geochemistry and isotopes; (2) mixing seen in zoned plutons and synplutonic dykes and enclaves occurred early; (3) zoned plagioclase phenocrysts commonly show very complex life histories of growth and dissolution; (4) mafic end-members in hybrids are commonly fractionated magmas and (5) stratification in subvolcanic granitoid magma chambers is not uncommon, and stratification has been identified in some deeper level plutons. Hybridization must overcome the tendency to form a stable stratification of dense mafic magma underlying less dense felsic magma. Experimental work with magma analogues and theoretical considerations reveal very severe thermal, rheological and dynamical limitations on mixing: only very similar (composition, temperature) magmas are likely to mix to homogeneity, and only moderately silicic hybrids are likely to be produced. However, "impossibly" silicic hybrids do exist. Synchronous, interactive fractional crystallization and hybridization may provide a mechanism for hybridization of magmas, in the following manner. A mafic magma intrudes into the base of a stratified felsic magma and is cooled against it. Crystallization of the upper boundary layer of the mafic magma yields an eventually buoyant residual melt that overturns and mixes with an adjacent stratum of the felsic magma chamber. Subsequently, melt released by crystallization pf this, now-hybrid zone mixes with adjacent, more felsic zones. Thus, a suite of hybrid magmas are progressively formed. Density inhibitions are overcome by the generation of relatively low density residual melts. As crystallization proceeds, later injections are preserved as dykes and enclaves composed of hybrid magma. In this process, only physically adjacent and dynamically-thermally similar magmas directly interact, and so may mix to homogeneity. Finally, not simply felsic and mafic endmembers mix, but a whole suite of "intermediate" endmembers participate, ranging from relatively mafic through to felsic pairs of magmas. Direct mixing between the primary magmas only occurs at the beginning.

Understanding groundwater, surface water, and hyporheic zone biogeochemical processes in a Chalk catchment using fluorescence properties of dissolved and colloidal organic matter

NASA Astrophysics Data System (ADS)

Lapworth, D. J.; Gooddy, D. C.; Allen, D.; Old, G. H.

2009-09-01

Understanding groundwater-surface water (GW-SW) interaction in Chalk catchments is complicated by the degree of geological heterogeneity. At this study site, in southern United Kingdom, alluvial deposits in the riparian zone can be considered as a patchwork of varying grades and types with an equally varied lateral connectivity. Some display good connection with the river system and others good connection with the groundwater system and, by definition, poorer connectivity with the surface water. By coupling tangential flow fractionation (TFF) with fluorescence analysis we were able to characterize the organic matter in the river and hyporheic zone. There is a significant proportion of particulate and colloidal fluorescent organic matter (FOM) within the river system and at depth within the gravels beneath the river channel. At depth in the hyporheic zone, the surface water inputs are dampened by mixing with deeper groundwater FOM. The shallow (0-0.5 m below river bed) hyporheic zone is highly dynamic as a result of changing surface water inputs from upstream processes. Labile C in the form of protein-like FOM appears to be attenuated preferentially compared to fulvic-like fluorescence in the hyporheic zone compared to the adjacent gravel and sand deposits. These preliminary findings have important implications for understanding nutrient and trace element mobility and attenuation within the groundwater, surface water, and hyporheic zone of permeable Chalk catchments. Fluorescence analysis of dissolved organic matter has been shown to be a useful environmental tracer that can be used in conjunction with other methods to understand GW-SW processes within a permeable Chalk catchment.

Computational fluid dynamics assessment: Volume 2, Isothermal simulations of the METC bench-scale coal-water slurry combustor: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Celik, I.; Chattree, M.

1988-09-01

The isothermal turbulent, swirling flow inside the METC pressurized bench-scale combustor has been simulated using ISOPCGC-2. The effects of the swirl numbers, the momentum ratio of the primary to secondary streams, the annular wall thickness, and the quarl angle on the flow and mixing patterns have been investigated. The results that with the present configuration of the combustor, an annular recirculation zone is present up to secondary swirl number of four. A central (on axis) recirculation zone can be obtained by increasing the momentum of the secondary stream by decreasing the annular area at the reactor inlet. The mixing ofmore » the primary (fuel carrier) air with the secondary air improves only slightly due to swirl unless a central recirculation zone is present. Good mixing is achieved in the quarl region when a central recirculation zone is present. A preliminary investigation of the influence of placing flow regulators inside the the combustor shows that they influence the flow field significantly and that there is a potential of obtaining optimum flow conditions using these flow regulators. 58 refs., 47 figs., 12 tabs.« less

Nitrogen biogeochemistry of submarine groundwater discharge

USGS Publications Warehouse

Kroeger, K.D.; Charette, M.A.

2008-01-01

To investigate the role of the seepage zone in transport, chemical speciation, and attenuation of nitrogen loads carried by submarine groundwater discharge, we collected nearshore groundwater samples (n = 328) and examined the distribution and isotopic signature (δ15N) of nitrate and ammonium. In addition, we estimated nutrient fluxes from terrestrial and marine groundwater sources. We discuss our results in the context of three aquifer zones: a fresh groundwater zone, a shallow salinity transition zone (STZ), and a deep STZ. Groundwater plumes containing nitrate and ammonium occurred in the freshwater zone, whereas the deep STZ carried almost exclusively ammonium. The distributions of redox-cycled elements were consistent with theoretical thermodynamic stability of chemical species, with sharp interfaces between water masses of distinct oxidation : reduction potential, suggesting that microbial transformations of nitrogen were rapid relative to dispersive mixing. In limited locations in which overlap occurs between distribution of nitrate with that of ammonium and dissolved Fe2+, changes in concentration and in δ15N suggest loss of all species. Concurrent removal of NO3− and NH4+, both in freshwater and the deep STZ, might occur through a range of mechanisms, including heterotrophic or autotrophic denitrification, coupled nitrfication : denitrification, anammox, or Mn oxidation of NH4+. Loss of nitrogen was not apparent in the shallow STZ, perhaps because of short water residence time. Despite organic Cpoor conditions, the nearshore aquifer and subterranean estuary are biogeochemically active zones, where attenuation of N loads can occur. Extent of attenuation is controlled by the degree of mixing of biogeochemically dissimilar water masses, highlighting the critical role of hydrogeology in N biogeochemistry. Mixing is related in part to thinning of the freshwater lens before discharge and to dispersion at the fresh : saline groundwater interface, features common to all submarine groundwater discharge zones.

Regional Hydrogeochemistry of a Modern Coastal Mixing Zone

NASA Astrophysics Data System (ADS)

Wicks, Carol M.; Herman, Janet S.

1996-02-01

In west central Florida, groundwater samples were collected along flow paths in the unconfined upper Floridan aquifer that cross the inland, freshwater recharge area and the coastal discharge area. A groundwater flow and solute transport model was used to evaluate groundwater flow and mixing of fresh and saline groundwater along a cross section of the unconfined upper Floridan aquifer. Results show that between 8% and 15% of the fresh and 30-31% of the saline groundwater penetrates to the depth in the flow system where contact with and dissolution of gypsum is likely. The deeply circulating fresh and saline groundwater returns to the near-surface environment discharging CaSO4-rich water to the coastal area where it mixes with fresh CaHCO3 groundwater, resulting in a prediction of calcite precipitation in the modern mixing zone.

Convective Overshoot in Stellar Interior

NASA Astrophysics Data System (ADS)

Zhang, Q. S.

2015-07-01

In stellar interiors, the turbulent thermal convection transports matters and energy, and dominates the structure and evolution of stars. The convective overshoot, which results from the non-local convective transport from the convection zone to the radiative zone, is one of the most uncertain and difficult factors in stellar physics at present. The classical method for studying the convective overshoot is the non-local mixing-length theory (NMLT). However, the NMLT bases on phenomenological assumptions, and leads to contradictions, thus the NMLT was criticized in literature. At present, the helioseismic studies have shown that the NMLT cannot satisfy the helioseismic requirements, and have pointed out that only the turbulent convection models (TCMs) can be accepted. In the first part of this thesis, models and derivations of both the NMLT and the TCM were introduced. In the second part, i.e., the work part, the studies on the TCM (theoretical analysis and applications), and the development of a new model of the convective overshoot mixing were described in detail. In the work of theoretical analysis on the TCM, the approximate solution and the asymptotic solution were obtained based on some assumptions. The structure of the overshoot region was discussed. In a large space of the free parameters, the approximate/asymptotic solutions are in good agreement with the numerical results. We found an important result that the scale of the overshoot region in which the thermal energy transport is effective is 1 HK (HK is the scale height of turbulence kinetic energy), which does not depend on the free parameters of the TCM. We applied the TCM and a simple overshoot mixing model in three cases. In the solar case, it was found that the temperature gradient in the overshoot region is in agreement with the helioseismic requirements, and the profiles of the solar lithium abundance, sound speed, and density of the solar models are also improved. In the low-mass stars of open clusters Hyades, Praesepe, NGC6633, NGC752, NGC3680, and M67, using the model and parameter same to the solar case to deal with the convective envelope overshoot mixing, the lithium abundances on the surface of the stellar models were consistent with the observations. In the case of the binary HY Vir, the same model and parameter also make the radii and effective temperatures of HY Vir stars with convective cores be consistent with the observations. Based on the implications of the above results, we found that the simple overshoot mixing model may need to be improved significantly. Motivated by those implications, we established a new model of the overshoot mixing based on the fluid dynamic equations, and worked out the diffusion coefficient of convective mixing. The diffusion coefficient shows different behaviors in convection zone and overshoot region. In the overshoot region, the buoyancy does negative works on flows, thus the fluid flows around the equilibrium location, which leads to a small scale and low efficiency of overshoot mixing. The physical properties are significantly different from the classical NMLT, and consistent with the helioseismic studies and numerical simulations. The new model was tested in stellar evolution, and its parameter was calibrated.

Experimental and Modeling Investigation of the Effect of Air Preheat on the Formation of NOx in an RQL Combustor

NASA Technical Reports Server (NTRS)

Samuelsen, G. S.; Brouwer, J.; Vardakas, M. A.; Holderman, J. D.

2012-01-01

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor concept has been proposed to minimize the formation of oxides of nitrogen (NOx) in gas turbine systems. The success of this low-NOx combustor strategy is dependent upon the links between the formation of NOx, inlet air preheat temperature, and the mixing of the jet air and fuel-rich streams. Chemical equilibrium and kinetics modeling calculations and experiments were performed to further understand NOx emissions in an RQL combustor. The results indicate that as the temperature at the inlet to the mixing zone increases (due to preheating and/or operating conditions) the fuel-rich zone equivalence ratio must be increased to achieve minimum NOx formation in the primary zone of the combustor. The chemical kinetics model illustrates that there is sufficient residence time to produce NOx at concentrations that agree well with the NOx measurements. Air preheat was found to have very little effect on mixing, but preheating the air did increase NOx emissions significantly. By understanding the mechanisms governing NOx formation and the temperature dependence of key reactions in the RQL combustor, a strategy can be devised to further reduce NOx emissions using the RQL concept.

Species abundances, guild dominance patterns, and community structure of breeding riparian birds

Treesearch

Deborah M. Finch

1989-01-01

I investigated trends in bird species populations, guild structure, and bird communities along a riparian altitudinal cline in the Medicine Bow National Forest of southeastern Wyoming. Streamside habitats were divided into three elevational zones: low-elevation (2050 to 2260 m) cottonwood zone, mid-elevation (2290 to 2530 m) mixed shrub willow zone, and high elevation...

Flavopiridol in Treating Patients With Relapsed or Refractory Lymphoma or Multiple Myeloma

ClinicalTrials.gov

2016-06-27

Adult Lymphocyte Depletion Hodgkin Lymphoma; Adult Lymphocyte Predominant Hodgkin Lymphoma; Adult Mixed Cellularity Hodgkin Lymphoma; Adult Nodular Sclerosis Hodgkin Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Refractory Multiple Myeloma; Splenic Marginal Zone Lymphoma; Stage I Multiple Myeloma; Stage II Multiple Myeloma; Stage III Multiple Myeloma; Waldenström Macroglobulinemia

Predicting groundwater redox status on a regional scale using linear discriminant analysis.

PubMed

Close, M E; Abraham, P; Humphries, B; Lilburne, L; Cuthill, T; Wilson, S

2016-08-01

Reducing conditions are necessary for denitrification, thus the groundwater redox status can be used to identify subsurface zones where potentially significant nitrate reduction can occur. Groundwater chemistry in two contrasting regions of New Zealand was classified with respect to redox status and related to mappable factors, such as geology, topography and soil characteristics using discriminant analysis. Redox assignment was carried out for water sampled from 568 and 2223 wells in the Waikato and Canterbury regions, respectively. For the Waikato region 64% of wells sampled indicated oxic conditions in the water; 18% indicated reduced conditions and 18% had attributes indicating both reducing and oxic conditions termed "mixed". In Canterbury 84% of wells indicated oxic conditions; 10% were mixed; and only 5% indicated reduced conditions. The analysis was performed over three different well depths, <25m, 25 to 100 and >100m. For both regions, the percentage of oxidised groundwater decreased with increasing well depth. Linear discriminant analysis was used to develop models to differentiate between the three redox states. Models were derived for each depth and region using 67% of the data, and then subsequently validated on the remaining 33%. The average agreement between predicted and measured redox status was 63% and 70% for the Waikato and Canterbury regions, respectively. The models were incorporated into GIS and the prediction of redox status was extended over the whole region, excluding mountainous land. This knowledge improves spatial prediction of reduced groundwater zones, and therefore, when combined with groundwater flow paths, improves estimates of denitrification. Copyright © 2016 Elsevier B.V. All rights reserved.

Geophysical evaluation of sandstone aquifers in the Reconcavo-Tucano Basin, Bahia -- Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lima, O.A.L. de

1993-11-01

The upper clastic sediments in the Reconcavo-Tucano basin comprise a multilayer aquifer system of Jurassic age. Its groundwater is normally fresh down to depths of more than 1,000 m. Locally, however, there are zones producing high salinity or sulfur geothermal water. Analysis of electrical logs of more than 150 wells enabled the identification of the most typical sedimentary structures and the gross geometries for the sandstone units in selected areas of the basin. Based on this information, the thick sands are interpreted as coalescent point bars and the shales as flood plain deposits of a large fluvial environment. The resistivitymore » logs and core laboratory data are combined to develop empirical equations relating aquifer porosity and permeability to log-derived parameters such as formation factor and cementation exponent. Temperature logs of 15 wells were useful to quantify the water leakage through semiconfining shales. The groundwater quality was inferred from spontaneous potential (SP) log deflections under control of chemical analysis of water samples. An empirical chart is developed that relates the SP-derived water resistivity to the true water resistivity within the formations. The patterns of salinity variation with depth inferred from SP logs were helpful in identifying subsurface flows along major fault zones, where extensive mixing of water is taking place. A total of 49 vertical Schlumberger resistivity soundings aid in defining aquifer structures and in extrapolating the log derived results. Transition zones between fresh and saline waters have also been detected based on a combination of logging and surface sounding data. Ionic filtering by water leakage across regional shales, local convection and mixing along major faults and hydrodynamic dispersion away from lateral permeability contrasts are the main mechanisms controlling the observed distributions of salinity and temperature within the basin.« less

Semidiurnal Temperature Changes Caused by Tidal Front Movements in the Warm Season in Seabed Habitats on the Georges Bank Northern Margin and Their Ecological Implications

PubMed Central

Guida, Vincent G.; Valentine, Page C.; Gallea, Leslie B.

2013-01-01

Georges Bank is a large, shallow feature separating the Gulf of Maine from the Atlantic Ocean. Previous studies demonstrated a strong tidal-mixing front during the warm season on the northern bank margin between thermally stratified water in the Gulf of Maine and mixed water on the bank. Tides transport warm water off the bank during flood tide and cool gulf water onto the bank during ebb tide. During 10 days in August 2009, we mapped frontal temperatures in five study areas along ∼100 km of the bank margin. The seabed “frontal zone”, where temperature changed with frontal movment, experienced semidiurnal temperature maxima and minima. The tidal excursion of the frontal boundary between stratified and mixed water ranged 6 to 10 km. This “frontal boundary zone” was narrower than the frontal zone. Along transects perpendicular to the bank margin, seabed temperature change at individual sites ranged from 7.0°C in the frontal zone to 0.0°C in mixed bank water. At time series in frontal zone stations, changes during tidal cycles ranged from 1.2 to 6.1°C. The greatest rate of change (−2.48°C hr−1) occurred at mid-ebb. Geographic plots of seabed temperature change allowed the mapping of up to 8 subareas in each study area. The magnitude of temperature change in a subarea depended on its location in the frontal zone. Frontal movement had the greatest effect on seabed temperature in the 40 to 80 m depth interval. Subareas experiencing maximum temperature change in the frontal zone were not in the frontal boundary zone, but rather several km gulfward (off-bank) of the frontal boundary zone. These results provide a new ecological framework for examining the effect of tidally-driven temperature variability on the distribution, food resources, and reproductive success of benthic invertebrate and demersal fish species living in tidal front habitats. PMID:23405129

Differentiation and magma mixing on Kilauea's east rift zone: A further look at the eruptions of 1955 and 1960. Part II. The 1960 lavas

USGS Publications Warehouse

Wright, T.L.; Helz, R.T.

1996-01-01

New and detailed petrographic observations, mineral compositional data, and whole-rock vs glass compositional trends document magma mixing in lavas erupted from Kilauea's lower east rift zone in 1960. Evidence includes the occurrence of heterogeneous phenocryst assemblages, including resorbed and reversely zoned minerals in the lavas inferred to be hybrids. Calculations suggest that this mixing, which is shown to have taken place within magma reservoirs recharged at the end of the 1955 eruption, involved introduction of four different magmas. These magmas originated beneath Kilauea's summit and moved into the rift reservoirs beginning 10 days after the eruption began. We used microprobe analyses of glass to calculate temperatures of liquids erupted in 1955 and 1960. We then used the calculated proportions of stored and recharge components to estimate the temperature of the recharge components, and found those temperatures to be consistent with the temperature of the same magmas as they appeared at Kilauea's summit. Our studies reinforce conclusions reached in previous studies of Kilauea's magmatic plumbing. We infer that magma enters shallow storage beneath Kilauea's summit and also moves laterally into the fluid core of the East rift zone. During this process, if magmas of distinctive chemistry are present, they retain their chemical identity and the amount of cooling is comparable for magma transported either upward or laterally to eruption sites. Intrusions within a few kilometers of the surface cool and crystallize to produce fractionated magma. Magma mixing occurs both within bodies of previously fractionated magma and when new magma intersects a preexisting reservoir. Magma is otherwise prevented from mixing, either by wall-rock septa or by differing thermal and density characteristics of the successive magma batches.

Sorafenib in Treating Patients With Metastatic or Unresectable Solid Tumors, Multiple Myeloma, or Non-Hodgkin's Lymphoma With or Without Impaired Liver or Kidney Function

ClinicalTrials.gov

2013-01-04

Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Multiple Myeloma; Splenic Marginal Zone Lymphoma; Stage II Multiple Myeloma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Multiple Myeloma; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

An analytical model for non-conservative pollutants mixing in the surf zone.

PubMed

Ki, Seo Jin; Hwang, Jin Hwan; Kang, Joo-Hyon; Kim, Joon Ha

2009-01-01

Accurate simulation of the surf zone is a prerequisite to improve beach management as well as to understand the fundamentals of fate and transport of contaminants. In the present study, a diagnostic model modified from a classic solute model is provided to illuminate non-conservative pollutants behavior in the surf zone. To readily understand controlling processes in the surf zone, a new dimensionless quantity is employed with index of kappa number (K, a ratio of inactivation rate to transport rate of microbial pollutant in the surf zone), which was then evaluated under different environmental frames during a week simulation period. The sensitivity analysis showed that hydrodynamics and concentration gradients in the surf zone mostly depend on n (number of rip currents), indicating that n should be carefully adjusted in the model. The simulation results reveal, furthermore, that large deviation typically occurs in the daytime, signifying inactivation of fecal indicator bacteria is the main process to control surf zone water quality during the day. Overall, the analytical model shows a good agreement between predicted and synthetic data (R(2) = 0.51 and 0.67 for FC and ENT, respectively) for the simulated period, amplifying its potential use in the surf zone modelling. It is recommended that when the dimensionless index is much larger than 0.5, the present modified model can predict better than the conventional model, but if index is smaller than 0.5, the conventional model is more efficient with respect to time and cost.

High Winds and the Vertical Structure of Chl-a in the Southern Ocean: Insights from Remote Sensing and Novel in situ Sensors

NASA Astrophysics Data System (ADS)

Carranza, M. M.; Gille, S. T.; Franks, P. J. S.; Johnson, K. S.; Girton, J. B.

2016-02-01

The Southern Ocean is under the influence of strong atmospheric synoptic activity and contains some of the oceans deepest mixed layers. Deep mixed layers can transport phytoplankton below the euphotic zone, and phytoplankton growth is hypothesized to be co-limited by iron and light. Atmospheric forcing drives changes in the mixed-layer depth (MLD) that influence light levels and nutrient input to the euphotic zone. In summer, when the MLD is shallow and close to the euphotic depth, high satellite Chl-a correlate with high winds, consistent with wind-driven entrainment that can potentially increase nutrient concentrations in the euphotic zone. However, correlations between Chl-a and diurnal winds are largest at zero time lag. High winds can inject nutrients on short timescales (< 1 day), but in situ incubation experiments after iron addition indicate phytoplankton growth on slightly longer timescales (> 3-4 days), suggesting that the correlations are not a result of growth. High winds can also entrain Chl-a from a subsurface Chl-a maximum. Novel bio-optical sensors mounted on elephant seals and autonomous floats allow us to examine the vertical structure of Chl-a in the Southern Ocean. In this study, we investigate the occurrence of subsurface Chl-a maxima. We find that surface Chl-a is a relatively good proxy for depth-integrated Chl-a within the euphotic zone but gives an inadequate representation of biomass within the mixed layer, particularly in the summer. Subsurface Chl-a maxima are not uncommon and may occur in all seasons. Chl-a maxima that correlate with particle backscattering in summer and fall are found near the base of the mixed layer, closer to the nutrient maximum than the light maximum, suggesting that nutrient limitation (i.e., essentially iron) can play a greater role than light limitation in governing productivity, and that high winds potentially entrain a subsurface Chl-a maximum into the summer mixed layer.

An integral turbulent kinetic energy analysis of free shear flows

NASA Technical Reports Server (NTRS)

Peters, C. E.; Phares, W. J.

1973-01-01

Mixing of coaxial streams is analyzed by application of integral techniques. An integrated turbulent kinetic energy (TKE) equation is solved simultaneously with the integral equations for the mean flow. Normalized TKE profile shapes are obtained from incompressible jet and shear layer experiments and are assumed to be applicable to all free turbulent flows. The shear stress at the midpoint of the mixing zone is assumed to be directly proportional to the local TKE, and dissipation is treated with a generalization of the model developed for isotropic turbulence. Although the analysis was developed for ducted flows, constant-pressure flows were approximated with the duct much larger than the jet. The axisymmetric flows under consideration were predicted with reasonable accuracy. Fairly good results were also obtained for the fully developed two-dimensional shear layers, which were computed as thin layers at the boundary of a large circular jet.

Size matters: The effects of displacement magnitude on the fluid flow properties of faults in poorly lithified sediments

NASA Astrophysics Data System (ADS)

Loveless, S. E.; Bense, V.; Turner, J.

2011-12-01

Many aquifers worldwide occur in poorly lithified sediments, often in regions that experience active tectonic deformation. Faulting of these sediments introduces heterogeneities that may affect aquifer porosity and permeability, and consequently subsurface fluid flow and groundwater storage. The specific hydrogeological effects of faults depend upon the fault architecture and deformation mechanisms. These are controlled by factors such as rheology, stratigraphy and burial depth. Here, we analyse fault permeability in poorly lithified sediments as a function of fault displacement. We have carried out detailed outcrop studies of minor normal faults at five study sites within the rapidly extending Corinth rift, Central Greece. Gravel conglomerates of giant Gilbert delta facies form productive but localised shallow aquifers within the region. Exposures reveal dense (average 20 faults per 100 m) networks of minor (0.1 to 50 m displacement) normal faults within the uplifted sequences, proximal to many of the crustal-scale normal faults. Analysis of 42 faults shows that fault zones are primarily composed of smeared beds that can either retain their definition or mix with surrounding sediment. Lenses or blocks of sediment are common in fault zones that cut beds with contrasting rheology, and a few faults have a clay core and/or damage zone. Fault thickness increases at a rate of about 0.4 m per 10 m increase in displacement. Comparison of sediment micro-structures from the field, hand samples and thin sections show grain-scale sediment mixing, fracturing of clasts, and in some cases cementation, within fault zones. In faults with displacements >12 m we also find a number of roughly parallel, highly indurated shear planes, up to 20 mm in thickness, composed of highly fragmented clasts and a fine grained matrix. Image analysis of thin sections from hand samples collected in the field was used to quantify the porosity of fault zones and adjacent undeformed sediment. These data show a reduction in average porosity from 21% (± 4) in undisturbed sediments to 14% (± 8) within fault zones. We find that fault zone porosity decreases by approximately 5% per 1 m displacement (up to 2 m displacement), as sediments undergo greater micro-scale deformation. Porosity within the shear planes of larger displacement faults (> 12 m) is significantly less than 5%. In summary, with an increase in fault displacement there is an increase in fault thickness and decrease in fault zone porosity, in addition to the occurrence of extremely low porosity shear planes. Consequently, the impact of faults in poorly lithified sediment on fluid flow is, to a large degree, dependent upon the magnitude of fault displacement.

Center for the Built Environment: Research on Building Envelope Systems

Science.gov Websites

Studies Facade and Perimeter Zone Field Study Facades and Thermal Comfort Facade Symposium Mixed-Mode Research Adaptive Comfort Model Mixed-Mode Case Studies Operable Windows and Thermal Comfort Occupant thermal preferences in naturally ventilated as sealed buildings? Case Study Research of Mixed-Mode Office

Ocean stratification reduces melt rates at the grounding zone of the Ross Ice Shelf

NASA Astrophysics Data System (ADS)

Begeman, C. B.; Tulaczyk, S. M.; Marsh, O.; Mikucki, J.; Stanton, T. P.; Hodson, T. O.; Siegfried, M. R.; Powell, R. D.; Christianson, K. A.; King, M. A.

2017-12-01

Ocean-driven melting of ice shelves is often invoked as the primary mechanism for triggering ice loss from Antarctica. However, due to the difficulty in accessing the sub-ice-shelf ocean cavity, the relationship between ice-shelf melt rates and ocean conditions is poorly understood, particularly near the transition from grounded to floating ice, known as the grounding zone. Here we present the first borehole oceanographic observations from the grounding zone of Antarctica's largest ice shelf. Contrary to predictions that tidal currents near grounding zones should mix the water column, driving high ice-shelf melt rates, we find a stratified sub-ice-shelf water column. The vertical salinity gradient dominates stratification over a weakly unstable vertical temperature gradient; thus, stratification takes the form of a double-diffusive staircase. These conditions limit vertical heat fluxes and lead to low melt rates in the ice-shelf grounding zone. While modern grounding zone melt rates may presently be overestimated in models that assume efficient tidal mixing, the high sensitivity of double-diffusive staircases to ocean freshening and warming suggests future melt rates may be underestimated, biasing projections of global sea-level rise.

Element mixing distribution and structure feature of fusion zone in laser welding between different alloys and pure titanium.

PubMed

Wu, Haishu; Liu, Jihong; Liu, Xuecheng; Li, Changyi; Yu, Zhiwei

2002-07-01

To study micro morphology and element-mixing distribution of different alloys welded in laser and analyze the feasibility of laser welding different alloys. Alloys and titanium were matched into 4 groups: Au-Pt with Ni-Cr; Au-Pt with pure Ti; pure Ti with Ni-Cr; Ni-Cr with Co-Cr. They were welded in laser. Changes in metallography after hybridization of crystalline grain, ranges of heat-affected zone and pores were observed through SEM with ultra-thin windowed X-ray energy atlas. Meanwhile 10 testing points were chosen with area of 300 micro m x 900 micro m along the welding surface from the side A alloy to the side B alloy, than the element mixing distribution and tendency were analyzed with X-ray energy atlas. 1. Hybridization of different alloys: (l) in the group of Au-Pt with Ti, there was titanium element mixing into Au-Pt tissue gradually and evenly on the Au-Pt side of the interface without clear boundary and increasing in size of crystalline grain. However, there was titanium crystalline grain increasing in size, irregular morphology and small sacks on the titanium side with clear boundary. (2) in the group of Ni-Cr with Ti, there was mixing regularly, slow transition and interlocks between crystalline grains on the Ni-Cr side of the in terface. Poor transition, clear boundary and small cracks were observed on titanium side. (3) in the group of Co-Cr with Ni-Cr, there was good transition, obscure boundary on both sides resulting from network, cylinder and branch structure growing. 2. Element-mixing distribution of different alloys. In fusion zone, the metal elements in matched groups mixed well and hybridized into new alloys except titanium blocks. The location of wave peak depended on the composition of alloys. Most of elements were from the alloy far from the fusion zone. The hybridization between pure titanium and any other alloys is not good The effect of laser welding different alloys is ideal except with pure titanium.

Evaluation of joint probability density function models for turbulent nonpremixed combustion with complex chemistry

NASA Technical Reports Server (NTRS)

Smith, N. S. A.; Frolov, S. M.; Bowman, C. T.

1996-01-01

Two types of mixing sub-models are evaluated in connection with a joint-scalar probability density function method for turbulent nonpremixed combustion. Model calculations are made and compared to simulation results for homogeneously distributed methane-air reaction zones mixing and reacting in decaying turbulence within a two-dimensional enclosed domain. The comparison is arranged to ensure that both the simulation and model calculations a) make use of exactly the same chemical mechanism, b) do not involve non-unity Lewis number transport of species, and c) are free from radiation loss. The modified Curl mixing sub-model was found to provide superior predictive accuracy over the simple relaxation-to-mean submodel in the case studied. Accuracy to within 10-20% was found for global means of major species and temperature; however, nitric oxide prediction accuracy was lower and highly dependent on the choice of mixing sub-model. Both mixing submodels were found to produce non-physical mixing behavior for mixture fractions removed from the immediate reaction zone. A suggestion for a further modified Curl mixing sub-model is made in connection with earlier work done in the field.

Lenalidomide and Combination Chemotherapy (DA-EPOCH-R) in Treating Patients With MYC-Associated B-Cell Lymphomas

ClinicalTrials.gov

2017-09-28

Adult Grade III Lymphomatoid Granulomatosis; B-cell Chronic Lymphocytic Leukemia; Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Contiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Contiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Contiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Contiguous Stage II Grade 1 Follicular Lymphoma; Contiguous Stage II Grade 2 Follicular Lymphoma; Contiguous Stage II Grade 3 Follicular Lymphoma; Contiguous Stage II Mantle Cell Lymphoma; Contiguous Stage II Marginal Zone Lymphoma; Contiguous Stage II Small Lymphocytic Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Progressive Hairy Cell Leukemia, Initial Treatment; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage 0 Chronic Lymphocytic Leukemia; Stage I Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Mixed Cell Lymphoma; Stage I Adult Diffuse Small Cleaved Cell Lymphoma; Stage I Adult Hodgkin Lymphoma; Stage I Adult Immunoblastic Large Cell Lymphoma; Stage I Chronic Lymphocytic Leukemia; Stage I Grade 1 Follicular Lymphoma; Stage I Grade 2 Follicular Lymphoma; Stage I Grade 3 Follicular Lymphoma; Stage I Mantle Cell Lymphoma; Stage I Marginal Zone Lymphoma; Stage I Small Lymphocytic Lymphoma; Stage II Adult Hodgkin Lymphoma; Stage II Chronic Lymphocytic Leukemia; Stage II Small Lymphocytic Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Chronic Lymphocytic Leukemia; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Chronic Lymphocytic Leukemia; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma; Testicular Lymphoma; Untreated Hairy Cell Leukemia; Waldenström Macroglobulinemia

Fluctuations in the East Asian monsoon recorded by pollen assemblages in sediments from the Japan Sea off the southwestern coast of Hokkaido, Japan, from 4.3 Ma to the present

NASA Astrophysics Data System (ADS)

Igarashi, Yaeko; Irino, Tomohisa; Sawada, Ken; Song, Lu; Furota, Satoshi

2018-04-01

We reconstructed fluctuations in the East Asian monsoon and vegetation in the Japan Sea region since the middle Pliocene based on pollen data obtained from sediments collected by the Integrated Ocean Drilling Program off the southwestern coast of northern Japan. Taxodiaceae conifers Metasequoia and Cryptomeria and Sciadopityacere conifer Sciadopitys are excellent indicators of a humid climate during the monsoon. The pollen temperature index (Tp) can be used as a proxy for relative air temperature. Based on changes in vegetation and reconstructed climate over a period of 4.3 Ma, we classified the sediment sequence into six pollen zones. From 4.3 to 3.8 Ma (Zone 1), the climate fluctuated between cool/moist and warm/moist climatic conditions. Vegetation changed between warm temperate mixed forest and cool temperate conifer forest. The Neogene type tree Carya recovered under a warm/moist climate. The period from 3.8 to 2.5 Ma (Zone 2) was characterized by increased Metasequoia pollen concentration. Warm temperate mixed forest vegetation developed under a cool/moist climate. The period from 2.5 to 2.2 Ma (Zone 3) was characterized by an abrupt increase in Metasequoia and/or Cryptomeria pollen and a decrease in warm broadleaf tree pollen, indicating a cool/humid climate. The Zone 4 period (2.2-1.7 Ma) was characterized by a decrease in Metasequoia and/or Cryptomeria pollen and an increase in cool temperate conifer Picea and Tsuga pollen, indicating a cool/moist climate. The period from 1.7 to 0.3 Ma (Zone 5) was characterized by orbital-scale climate fluctuations. Cycles of abrupt increases and decreases in Cryptomeria and Picea pollen and in Tp values indicated changes between warm/humid and cold/dry climates. The alpine fern Selaginella selaginoides appeared as of 1.6 Ma. Vegetation alternated among warm mixed, cool mixed, and cool temperate conifer forests. Zone 6 (0.3 Ma to present) was characterized by a decrease in Cryptomeria pollen. The warm temperate broadleaf forest and cool temperate conifer forest developed alternately under warm/moist and cold/dry climate. Zone 2 corresponded to a weak Tsushima Current breaking through the Tsushima Strait, and the beginning of orbital-scale climatic changes at 1.7 Ma during Zone 5 corresponded to the strong inflow of the Tsushima Current into the Japan Sea during interglacial periods (Gallagher et al., 2015).

Metasomatic Evolution in Tectonically Mixed Zones (Mélange) and Significance for Geochemical Evolution of the Slab-Mantle Interface

NASA Astrophysics Data System (ADS)

Bebout, G. E.; King, R. L.

2012-12-01

Fluid flow focused in highly deformed zones (shear zones), and the physical juxtaposition of chemically disparate rocks (via mechanical mixing) in such zones, can lead to extensive metasomatism, including volume strain, and result in rocks with hybridized compositions little resembling the compositions of the incorporated rock types [1-5]. In the Catalina Schist (California), lawsonite-albite, lawsonite-blueschist, and amphibolite-facies units contain shear zones at scales of meters to kilometers, each containing "blocks" (with more spherical or more tabular dimensions) co-facial in grade with the "matrix" surrounding these blocks [1-3]. Oxygen isotope data for these "mélange" units, and adjacent more "coherent" expanses, indicate enhanced fluid flow in the more strongly deforming mélange zones while fluid flow in coherent domains was dominantly fracture-controlled and episodic. The amphibolite-facies mélange unit shows evidence for km-scale equilibration of varying mineral assemblages with H2O-rich fluids with uniform O and H isotope compositions consistent with a lower-grade metasedimentary source. This unit is believed to have formed largely by mechanical mixing of mafic and ultramafic compositions, partly because of the scarcity of sedimentary blocks. However, the mélange matrix in this unit preserves a number of sedimentary chemical/isotopic characteristics (e.g., Pb isotope compositions [3]) that could reflect the incorporation of sedimentary rocks, with or without fluid-related fractionation, and possibly fluid-mediated additions. Tectonically mixed zones such as these, if volumetrically significant at the slab-mantle interface, could exert disproportionate control on the compositions of hydrous fluids or silicate melts emanating from subducting slabs and entering the forearc to backarc mantle wedge, including those contributing to arc magmatism [1-5]. Geochemical studies of arc lavas should consider the possibility that the "fluids" contributed from slabs to arc source regions bear chemical/isotopic signatures reflecting their interaction with these hybridized zones produced by mixing of varying proportions of sedimentary, mafic, and ultramafic compositions. Also, the high-variance hydrous mineral assemblages created by these coeval mechanical and metasomatic processes (e.g., nearly monomineralic chlorite, talc, and amphibole schists) could play an important role in the volatiles budgets at subduction zones (i.e., having stabilities to P and T significantly higher than those for mineral assemblages in metabasaltic and metasedimentary rocks containing the same mineral phases [1,4]). Field, petrologic/geochemical, theoretical, and geophysical studies should work toward assessment of the volumetric significance, physical properties, and devolatilization histories of these hybridized compositions. [1] Bebout and Barton (2002) Chem. Geol. 187:79-106 [2] King et al. (2006) Ear. Planet. Sci. Lett. 246:288-304 [3] King et al. (2007) Chem. Geol. 239:305-322 [4] Spandler et al. (2008) Contrib. Mineral. Petrol. 155:181-198 [5] Miller et al. (2009) Lithos 107:53-67

Observational Data Analysis and Numerical Model Assessment of the Seafloor Interaction and Mobility of Sand and Weathered Oil Agglomerates (Surface Residual Balls) in the Surf Zone

NASA Astrophysics Data System (ADS)

Dalyander, S.; Long, J.; Plant, N. G.; Penko, A.; Calantoni, J.; Thompson, D.; Mclaughlin, M. K.

2014-12-01

When weathered oil is transported ashore, such as during the Deepwater Horizon oil spill, it can mix with suspended sediment in the surf zone to create heavier-than-water sand and oil agglomerates in the form of mats several centimeters thick and tens of meters long. Broken off pieces of these mats and smaller agglomerates formed in situ (called Surface Residual Balls, SRBs) can cause beach re-oiling months to years after the initial spill. The physical dynamics of these SRBs in the nearshore, where they are larger (cm-scale) and less dense than natural sediment, are poorly understood. In the current study, SRB mobility and seafloor interaction is investigated through a combination of laboratory and field experiments with pseudo-SRBs developed to be physically stable proxies for genuine agglomerates. Formulations for mobility prediction based on comparing estimated shear stress to the critical Shields and modified Shields parameters developed for mixed sediment beds are assessed against observations. Processes such as burial, exhumation, and interaction with bedforms (e.g., migrating ripples) are also explored. The observations suggest that incipient motion estimates based on a modified Shields parameter have some skill in predicting SRB movement, but that other forcing mechanisms such as pressure gradients may be important under some conditions. Additionally, burial and exhumation due to the relatively high mobility of sand grains are confirmed as key processes controlling SRB dynamics in the surf zone. This work has broad implications for understanding surf zone sediment transport at the short timescale associated with mobilizing sand grains and SRBs as well as at the longer timescales associated with net transport patterns, sediment budgets, and bed elevation changes.

Close-in characteristics of LH2/LOX reactions

NASA Technical Reports Server (NTRS)

Riehl, W. A.; Ullian, L. J.

1985-01-01

In deriving shock overpressures from space vehicles employing LH2 and LOX, separate methods of analyses and prediction are recommended, as a function of the distance. Three methods of treatment are recommended. For the Far Field - where the expected shock overpressure is less than 40 psi (lambda = 5) - use the classical PYRO approach to determine TNT yield, and employ classical ordnance (Kingery) curve to obtain the overall value. For the Close-In Range, a suggested limit is 3D, or a zone from a distance of three times the tank diameter to the tank wall. Rather than estimate a specific distance from the center of explosion to the target, it is only necessary to estimate whether this could be within one, two, or three diameters away from the wall; i.e., in the 1, 2, or 3D zone. Then assess whether mixing mode is by the PYRO CBGS (spill) mode or CBM (internal mixing) mode. From the zone and mixing mode, the probability of attaining various shock overpressures is determined from the plots provided herein. For the transition zone, between 40 psi and the 3D distance, it is tentatively recommended that both of the preceding methods be used, and to be conservative, the higher resulting value be used.

System dynamics of behaviour-evolutionary mix-game models

NASA Astrophysics Data System (ADS)

Gou, Cheng-Ling; Gao, Jie-Ping; Chen, Fang

2010-11-01

In real financial markets there are two kinds of traders: one is fundamentalist, and the other is a trend-follower. The mix-game model is proposed to mimic such phenomena. In a mix-game model there are two groups of agents: Group 1 plays the majority game and Group 2 plays the minority game. In this paper, we investigate such a case that some traders in real financial markets could change their investment behaviours by assigning the evolutionary abilities to agents: if the winning rates of agents are smaller than a threshold, they will join the other group; and agents will repeat such an evolution at certain time intervals. Through the simulations, we obtain the following findings: (i) the volatilities of systems increase with the increase of the number of agents in Group 1 and the times of behavioural changes of all agents; (ii) the performances of agents in both groups and the stabilities of systems become better if all agents take more time to observe their new investment behaviours; (iii) there are two-phase zones of market and non-market and two-phase zones of evolution and non-evolution; (iv) parameter configurations located within the cross areas between the zones of markets and the zones of evolution are suited for simulating the financial markets.

Quantifying Hydro-biogeochemical Model Sensitivity in Assessment of Climate Change Effect on Hyporheic Zone Processes

NASA Astrophysics Data System (ADS)

Song, X.; Chen, X.; Dai, H.; Hammond, G. E.; Song, H. S.; Stegen, J.

2016-12-01

The hyporheic zone is an active region for biogeochemical processes such as carbon and nitrogen cycling, where the groundwater and surface water mix and interact with each other with distinct biogeochemical and thermal properties. The biogeochemical dynamics within the hyporheic zone are driven by both river water and groundwater hydraulic dynamics, which are directly affected by climate change scenarios. Besides that, the hydraulic and thermal properties of local sediments and microbial and chemical processes also play important roles in biogeochemical dynamics. Thus for a comprehensive understanding of the biogeochemical processes in the hyporheic zone, a coupled thermo-hydro-biogeochemical model is needed. As multiple uncertainty sources are involved in the integrated model, it is important to identify its key modules/parameters through sensitivity analysis. In this study, we develop a 2D cross-section model in the hyporheic zone at the DOE Hanford site adjacent to Columbia River and use this model to quantify module and parametric sensitivity on assessment of climate change. To achieve this purpose, We 1) develop a facies-based groundwater flow and heat transfer model that incorporates facies geometry and heterogeneity characterized from a field data set, 2) derive multiple reaction networks/pathways from batch experiments with in-situ samples and integrate temperate dependent reactive transport modules to the flow model, 3) assign multiple climate change scenarios to the coupled model by analyzing historical river stage data, 4) apply a variance-based global sensitivity analysis to quantify scenario/module/parameter uncertainty in hierarchy level. The objectives of the research include: 1) identifing the key control factors of the coupled thermo-hydro-biogeochemical model in the assessment of climate change, and 2) quantify the carbon consumption in different climate change scenarios in the hyporheic zone.

Numerical simulation and comparison of two ventilation methods for a restaurant - displacement vs mixed flow ventilation

NASA Astrophysics Data System (ADS)

Chitaru, George; Berville, Charles; Dogeanu, Angel

2018-02-01

This paper presents a comparison between a displacement ventilation method and a mixed flow ventilation method using computational fluid dynamics (CFD) approach. The paper analyses different aspects of the two systems, like the draft effect in certain areas, the air temperatureand velocity distribution in the occupied zone. The results highlighted that the displacement ventilation system presents an advantage for the current scenario, due to the increased buoyancy driven flows caused by the interior heat sources. For the displacement ventilation case the draft effect was less prone to appear in the occupied zone but the high heat emissions from the interior sources have increased the temperature gradient in the occupied zone. Both systems have been studied in similar conditions, concentrating only on the flow patterns for each case.

Bortezomib and Filgrastim in Promoting Stem Cell Mobilization in Patients With Non-Hodgkin Lymphoma or Multiple Myeloma Undergoing Stem Cell Transplant

ClinicalTrials.gov

2017-05-23

Adult Grade III Lymphomatoid Granulomatosis; B-cell Chronic Lymphocytic Leukemia; Contiguous Stage II Adult Burkitt Lymphoma; Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Contiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Contiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Contiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Contiguous Stage II Adult Lymphoblastic Lymphoma; Contiguous Stage II Grade 1 Follicular Lymphoma; Contiguous Stage II Grade 2 Follicular Lymphoma; Contiguous Stage II Grade 3 Follicular Lymphoma; Contiguous Stage II Mantle Cell Lymphoma; Contiguous Stage II Marginal Zone Lymphoma; Contiguous Stage II Small Lymphocytic Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Burkitt Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Adult Lymphoblastic Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Progressive Hairy Cell Leukemia, Initial Treatment; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Hairy Cell Leukemia; Refractory Multiple Myeloma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage I Adult Burkitt Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Mixed Cell Lymphoma; Stage I Adult Diffuse Small Cleaved Cell Lymphoma; Stage I Adult Immunoblastic Large Cell Lymphoma; Stage I Adult Lymphoblastic Lymphoma; Stage I Grade 1 Follicular Lymphoma; Stage I Grade 2 Follicular Lymphoma; Stage I Grade 3 Follicular Lymphoma; Stage I Mantle Cell Lymphoma; Stage I Marginal Zone Lymphoma; Stage I Multiple Myeloma; Stage I Small Lymphocytic Lymphoma; Stage II Multiple Myeloma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Multiple Myeloma; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma; Untreated Hairy Cell Leukemia; Waldenström Macroglobulinemia

Bryostatin 1 Plus Vincristine in Treating Patients With Progressive or Relapsed Non-Hodgkin's Lymphoma After Bone Marrow or Stem Cell Transplantation

ClinicalTrials.gov

2013-01-09

Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma

Sensitive detection of malachite green and crystal violet by nonlinear laser wave mixing and capillary electrophoresis.

PubMed

Maxwell, Eric J; Tong, William G

2016-05-01

An ultrasensitive label-free antibody-free detection method for malachite green and crystal violet is presented using nonlinear laser wave-mixing spectroscopy and capillary zone electrophoresis. Wave-mixing spectroscopy provides a sensitive absorption-based detection method for trace analytes. This is accomplished by forming dynamic gratings within a sample cell, which diffracts light to create a coherent laser-like signal beam with high optical efficiency and high signal-to-noise ratio. A cubic dependence on laser power and square dependence on analyte concentration make wave mixing sensitive enough to detect molecules in their native form without the use of fluorescent labels for signal enhancement. A 532 nm laser and a 635 nm laser were used for malachite green and crystal violet sample excitation. The use of two lasers of different wavelengths allows the method to simultaneously detect both analytes. Selectivity is obtained through the capillary zone electrophoresis separation, which results in characteristic migration times. Measurement in capillary zone electrophoresis resulted in a limit of detection of 6.9 × 10(-10)M (2.5 × 10(-19) mol) for crystal violet and 8.3 × 10(-11)M (3.0 × 10(-20) mol) for malachite green at S/N of 2. Copyright © 2016. Published by Elsevier B.V.

Lenalidomide Maintenance Therapy After High Dose BEAM With or Without Rituximab

ClinicalTrials.gov

2018-01-13

Adult Nasal Type Extranodal NK/T-cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Peripheral T-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Mycosis Fungoides/Sezary Syndrome; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Waldenström Macroglobulinemia

Spatial Patterns of Groundwater Biogeochemical Reactivity in an Intertidal Beach Aquifer

NASA Astrophysics Data System (ADS)

Kim, Kyra H.; Heiss, James W.; Michael, Holly A.; Cai, Wei-Jun; Laattoe, Tariq; Post, Vincent E. A.; Ullman, William J.

2017-10-01

Beach aquifers host a dynamic and reactive mixing zone between fresh and saline groundwater of contrasting origin and composition. Seawater, driven up the beachface by waves and tides, infiltrates into the aquifer and meets the seaward-discharging fresh groundwater, creating and maintaining a reactive intertidal circulation cell. Within the cell, land-derived nutrients delivered by fresh groundwater are transformed or attenuated. We investigated this process by collecting pore water samples from multilevel wells along a shore-perpendicular transect on a beach near Cape Henlopen, Delaware, and analyzing solute and particulate concentrations. Pore water incubation experiments were conducted to determine rates of oxygen consumption and nitrogen gas production. A numerical model was employed to support field and laboratory interpretations. Results showed that chemically sensitive parameters such as pH and ORP diverged from salinity distribution patterns, indicating biogeochemical reactivity within the circulation cell. The highest respiration rates were found in the landward freshwater-saltwater mixing zone, supported by high dissolved inorganic carbon. Chlorophyll a, a proxy for phytoplankton, and particulate carbon did not co-occur with the highest respiration rates but were heterogeneously distributed in deeper and hypoxic areas of the cell. The highest rates of N2 production were also found in the mixing zone coinciding with elevated O2 consumption rates but closer to the lower discharge point. Model results were consistent with these observations, showing heightened denitrification in the mixing zone. The results of this work emphasize the relationship between the physical flow processes of the circulation cell and its biogeochemical reactivity and highlight the environmental significance of sandy beaches.

Do rivermouths alter nutrient and seston delivery to the nearshore?

USGS Publications Warehouse

Larson, James H.; Frost, Paul C.; Vallazza, Jon M.; Nelson, John; Richardson, William B.

2016-01-01

Tributary inputs to lakes and seas are often measured at riverine gages, upstream of lentic influence. Between these riverine gages and the nearshore zones of large waterbodies lie rivermouths, which may retain, transform and contribute materials to the nearshore zone. However, the magnitude and timing of these rivermouth effects have rarely been measured.During the summer of 2011, 23 tributary systems of the Laurentian Great Lakes were sampled from river to nearshore for dissolved and particulate carbon (C), nitrogen (N) and phosphorus (P) concentrations, as well as bulk seston and chlorophyll a concentrations. Three locations per system were sampled: in the upstream river, in the nearshore zone and at the outflow from the rivermouth to the lake. Using stable oxygen isotopes, a water-mixing model was developed to estimate the nutrient concentration that would occur at the rivermouth if mixing was strictly conservative (i.e. if no processing occurred within the rivermouth). Deviations between these conservative mixing estimates and measured nutrient concentrations were identified as rivermouth effects on nutrient concentrations.Rivermouths had higher concentration of C and P than nearshore areas and more chlorophyll athan upstream river waters. Compared to the conservative mixing model, rivermouths as a class appeared to be summer-time sources of N, P and chlorophyll a. Substantial among rivermouth variation occurred both in the effect size and direction for all constituents.Using principal component analysis, two groups of rivermouths were identified: rivermouths that had a large effect on most constituents and those that had very little effect on any of the measured constituents. ‘High-effect’ rivermouths had more abundant upstream croplands, which were presumably the sources of inorganic nutrients. Cross-validated models built using characteristics of the rivermouth were not good predictors of variation in rivermouth effects on most constituents.For consumers feeding on seston and microbes and vascular autotrophs directly taking up dissolved nutrients, rivermouths are more resource-rich than upstream riverine or nearby Great Lakes waters. Given declines over time in open-lake productivity within the Great Lakes, rivermouths may contribute more productivity than their size would suggest to the Great Lakes food web.

Hydrogeochemistry of sodium-bicarbonate type bedrock groundwater in the Pocheon spa area, South Korea: water rock interaction and hydrologic mixing

NASA Astrophysics Data System (ADS)

Chae, Gi-Tak; Yun, Seong-Taek; Kim, Kangjoo; Mayer, Bernhard

2006-04-01

The Pocheon spa-land area, South Korea occurs in a topographically steep, fault-bounded basin and is characterized by a hydraulic upwelling flow zone of thermal water (up to 44 °C) in its central part. Hydrogeochemical and environmental isotope data for groundwater in the study area suggested the occurrence of two distinct water types, a Ca-HCO 3 type and a Na-HCO 3 type. The former water type is characterized by relatively high concentrations of Ca, SO 4 and NO 3, which show significant temporal variation indicating a strong influence by surface processes. In contrast, the Na-HCO 3 type waters have high and temporally constant temperature, pH, TDS, Na, Cl, HCO 3 and F, indicating the attainment of a chemical steady state with respect to the host rocks (granite and gneiss). Oxygen, hydrogen and tritium isotope data also indicate the differences in hydrologic conditions between the two groups: the relatively lower δ 18O, δD and tritium values for Na-HCO 3 type waters suggest that they recharged at higher elevations and have comparatively long mean residence times. Considering the geologic and hydrogeologic conditions of the study area, Na-HCO 3 type waters possibly have evolved from Ca-HCO 3 type waters. Mass balance modeling revealed that the chemistry of Na-HCO 3 type water was regulated by dissolution of silicates and carbonates and concurrent ion exchange. Particularly, low Ca concentrations in Na-HCO 3 water was mainly caused by cation exchange. Multivariate mixing and mass balance modeling (M3 modeling) was performed to evaluate the hydrologic mixing and mass transfer between discrete water masses occurring in the shallow peripheral part of the central spa-land area, where hydraulic upwelling occurs. Based on Q-mode factor analysis and mixing modeling using PHREEQC, an ideal mixing among three major water masses (surface water, shallow groundwater of Ca-HCO 3 type, deep groundwater of Na-HCO 3 type) was proposed. M3 modeling suggests that all the groundwaters in the spa area can be described as mixtures of these end-members. After mixing, the net mole transfer by geochemical reaction was less than that without mixing. Therefore, it is likely that in the hydraulic mixing zone geochemical reactions are of minor importance and, therefore, that mixing regulates the groundwater geochemistry.

In Situ NAPL Modification for Contaminant Source-Zone Passivation, Mass Flux Reduction, and Remediation

NASA Astrophysics Data System (ADS)

Mateas, D. J.; Tick, G.; Carroll, K. C.

2016-12-01

A remediation method was developed to reduce the aqueous solubility and mass-flux of target NAPL contaminants through the in-situ creation of a NAPL mixture source-zone. This method was tested in the laboratory using equilibrium batch tests and two-dimensional flow-cell experiments. The creation of two different NAPL mixture source zones were tested in which 1) volumes of relatively insoluble n-hexadecane (HEX) or vegetable oil (VO) were injected into a trichloroethene (TCE) contaminant source-zone; and 2) pre-determined HEX-TCE and VO-TCE mixture ratio source zones were emplaced into the flow cell prior to water flushing. NAPL-aqueous phase batch tests were conducted prior to the flow-cell experiments to evaluate the effects of various NAPL mixture ratios on equilibrium aqueous-phase concentrations of TCE and toluene (TOL) and to design optimal NAPL (HEX or VO) injection volumes for the flow-cell experiments. Uniform NAPL mixture source-zones were able to quickly decrease contaminant mass-flux, as demonstrated by the emplaced source-zone experiments. The success of the HEX and VO injections to also decrease mass flux was dependent on the ability of these injectants to homogeneously mix with TCE source-zone. Upon injection, both HEX and VO migrated away from the source-zone, to some extent. However, the lack of a steady-state dissolution phase and the inefficient mass-flux-reduction/mass-removal behavior produced after VO injection suggest that VO was more effective than HEX for mixing and partitioning within the source-zone region to form a more homogeneous NAPL mixture with TCE. VO appears to be a promising source-zone injectant-NAPL due to its negligible long-term toxicity and lower mobilization potential.

A new scaling law for temperature variance profile in the mixing zone of turbulent Rayleigh-Bénard convection

NASA Astrophysics Data System (ADS)

Wang, Yin; Xu, Wei; He, Xiao-Zhou; Yik, Hiu-Fai; Wang, Xiao-Ping; Schumacher, Jorg; Tong, Penger

2017-11-01

We report a combined experimental and numerical study of the scaling properties of the temperature variance profile η(z) along the central z axis of turbulent Rayleigh-Bénard convection in a thin disk cell and an upright cylinder of aspect ratio unity. In the mixing zone outside the thermal boundary layer region, the measured η(z) is found to scale with the cell height H in both cells and obey a power law, η(z) (z/H)ɛ, with the obtained values of ɛ being very close to -1. Based on the experimental and numerical findings, we derive a new equation for η(z) in the mixing zone, which has a power-law solution in good agreement with the experimental and numerical results. Our work thus provides a common framework for understanding the effect of boundary layer fluctuations on the scaling properties of the temperature variance profile in turbulent Rayleigh-Bénard convection. This work was supported in part by Hong Kong Research Grants Council.

Hot mix asphalt tender zone

DOT National Transportation Integrated Search

2000-04-01

Approximately 500 million tons of hot mix asphalt (HMA) are placed in the United States each year. With this large quantity of HMA, it is expected that some construction problems will occur from time to time. One problem that has been observed for ye...

Modeling tidal exchange and dispersion in Boston Harbor

USGS Publications Warehouse

Signell, Richard P.; Butman, Bradford

1992-01-01

Tidal dispersion and the horizontal exchange of water between Boston Harbor and the surrounding ocean are examined with a high-resolution (200 m) depth-averaged numerical model. The strongly varying bathymetry and coastline geometry of the harbor generate complex spatial patterns in the modeled tidal currents which are verified by shipboard acoustic Doppler surveys. Lagrangian exchange experiments demonstrate that tidal currents rapidly exchange and mix material near the inlets of the harbor due to asymmetry in the ebb/flood response. This tidal mixing zone extends roughly a tidal excursion from the inlets and plays an important role in the overall flushing of the harbor. Because the tides can only efficiently mix material in this limited region, however, harbor flushing must be considered a two step process: rapid exchange in the tidal mixing zone, followed by flushing of the tidal mixing zone by nontidal residual currents. Estimates of embayment flushing based on tidal calculations alone therefore can significantly overestimate the flushing time that would be expected under typical environmental conditions. Particle-release simulations from point sources also demonstrate that while the tides efficiently exchange material in the vicinity of the inlets, the exact nature of dispersion from point sources is extremely sensitive to the timing and location of the release, and the distribution of particles is streaky and patchlike. This suggests that high-resolution modeling of dispersion from point sources in these regions must be performed explicitly and cannot be parameterized as a plume with Gaussian-spreading in a larger scale flow field.

NUMERICAL SIMULATIONS OF THERMOHALINE CONVECTION: IMPLICATIONS FOR EXTRA-MIXING IN LOW-MASS RGB STARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denissenkov, Pavel A., E-mail: pavel.denisenkov@gmail.co

2010-11-01

Low-mass stars are known to experience extra-mixing in their radiative zones on the red giant branch (RGB) above the bump luminosity. To determine if the salt-fingering transport of chemical composition driven by {sup 3}He burning is efficient enough to produce RGB extra-mixing, two-dimensional numerical simulations of thermohaline convection for physical conditions corresponding to the RGB case have been carried out. We have found that the effective ratio of a salt finger's length to its diameter a{sub eff} {approx}< 0.5 is more than 10 times smaller than the value needed to reproduce observations (a{sub obs} {approx}> 7). On the other hand,more » using the thermohaline diffusion coefficient from linear stability analysis together with a = a{sub obs} is able to describe the RGB extra-mixing at all metallicities so well that it is tempting to believe that it may represent the true mechanism. In view of these results, follow-up three-dimensional numerical simulations of thermohaline convection for the RGB case are clearly needed.« less

Experimental study and simulation of phosphorus purification effects of bioretention systems on urban surface runoff

PubMed Central

Liang, Zheng; Li, Yajiao; Li, Peng; Jiang, Chunbo

2018-01-01

Excessive phosphorus (P) contributes to eutrophication by degrading water quality and limiting human use of water resources. Identifying economic and convenient methods to control soluble reactive phosphorus (SRP) pollution in urban runoff is the key point of rainwater management strategies. Through three series of different tests involving influencing factors, continuous operation and intermittent operation, this study explored the purification effects of bioretention tanks under different experimental conditions, it included nine intermittent tests, single field continuous test with three groups of different fillers (Fly ash mixed with sand, Blast furnace slag, and Soil), and eight intermittent tests with single filler (Blast furnace slag mixed with sand). Among the three filler combinations studied, the filler with fly ash mixed with sand achieved the best pollution reduction efficiency. The setting of the submerged zone exerted minimal influence on the P removal of the three filler combinations. An extension of the dry period slightly promoted the P purification effect. The combination of fly ash mixed with sand demonstrated a positive purification effect on SRP during short- or long-term simulated rainfall duration. Blast furnace slag also presented a positive purification effect in the short term, although its continuous purification effect on SRP was poor in the long term. The purification abilities of soil in the short and long terms were weak. Under intermittent operations across different seasons, SRP removal was unstable, and effluent concentration processes were different. The purification effect of the bioretention system on SRP was predicted through partial least squares regression (PLS) modeling analysis. The event mean concentration removal of SRP was positively related to the adsorption capacity of filler and rainfall interval time and negatively related to submerged zones, influent concentration and volume. PMID:29742120

Gas turbine premixing systems

DOEpatents

Kraemer, Gilbert Otto; Varatharajan, Balachandar; Evulet, Andrei Tristan; Yilmaz, Ertan; Lacy, Benjamin Paul

2013-12-31

Methods and systems are provided for premixing combustion fuel and air within gas turbines. In one embodiment, a combustor includes an upstream mixing panel configured to direct compressed air and combustion fuel through premixing zone to form a fuel-air mixture. The combustor includes a downstream mixing panel configured to mix additional combustion fuel with the fule-air mixture to form a combustion mixture.

Spatial and temporal variation of denitrification in the riparian zone during the hydrological year

NASA Astrophysics Data System (ADS)

Trauth, Nico; Musolff, Andreas; Knöller, Kay; Fleckenstein, Jan H.

2017-04-01

In the riparian zone, where stream water mixes with groundwater, biogeochemical reactions and solute transformations occur which may enhance the self-cleaning mechanisms of aquatic ecosystems. The water exchange and solute transport through the riparian zone is controlled by hydraulic gradients between stream and groundwater and thus varies seasonally and during stream discharge events. In this study, we focus on transport, mixing and the distribution of nitrate in the riparian zone of a gravelly alluvial aquifer with the aim to quantify its denitrification potential during the hydrological year. For this purpose, 25 groundwater wells were drilled along a 2 km stream section of the Selke river, a third-order stream in Germany. From the stream and the wells, water samples were taken 4-weekly over a period of 2 years. Water samples were analyzed to field parameters, major ions, dissolved organic carbon, and N-O isotopes. Results show a strong influence of the stream on the adjacent groundwater, which varies both in time and space. In general, we can distinguish between two endmembers: a) the stream water with low chloride (<30 mg/L) and nitrate (<10 mg/L) concentrations and b) the groundwater in 100m distance to the stream with high chloride (>70 mg/L) and nitrate (>50 mg/L) concentrations. Based on conservatively transported chloride, the mixing of the endmembers can be determined in the riparian zone. Deviations in nitrate concentrations from this mixing model may indicate nitrate degradation by e.g. denitrification. By combining this chloride-nitrate-ratio method with dissolved oxygen data and the isotopic signature of the nitrate molecule, we are able to determine the timing and the location of high denitrification patterns in the riparian aquifer. Highest variability of denitrification occurs over the year in terms of seasonality (temperature-driven) and is temporally fueled by additional organic carbon supply during discharge events.

Microstructural and mineral analysis on the fault gouge in the coseismic shear zone of the 2008 M w 7.9 Wenchuan earthquake

NASA Astrophysics Data System (ADS)

Yuan, Ren-mao; Zhang, Bing-liang; Xu, Xi-wei; Lin, Chuan-yong; Han, Zhu-jun

2015-07-01

The 2008 M w 7.9 Wenchuan earthquake formed two coseismic surface rupture zones with the trend of N35°E, known as the Beichuan-Yingxiu rupture and the Pengguan rupture. The Beichuan-Yingxiu rupture is the principle one with abundant fault gouge development along its length. In the exploratory trench at the Saba village along the Beichuan-Yingxiu rupture, the new fault gouge zone is only ~3 mm wide, which suggests that fault slip was constrained in a very narrow zone. In this study, we thus carried out detailed microstructural and mineral component analysis on the oriented fault gouge samples from the Saba exploratory trench to understand their features and geological implication. The results show that different microstructures of localized brittle deformation can be observed in the fault gouges, including Y-shear, R1-shear, R2-shear, P-shear as well as tension fracture, bookshelf glided structure and so on. These microstructures are commonly recognized as the product of seismic fault slipping. Furthermore, within the area between two parallel Y-shears of the fault gouge, a few of microstructures of distributed ductile deformations were developed, such as P-foliation, elongation and asymmetrical trailing structure of detrital particles. The microstructure features of fault gouges implicate the thrust movement of the fault during the Wenchuan earthquake. In addition, the fault gouge has less quartz and feldspar and more clay than the surrounding rocks, which indicates that some quartz and feldspar in the surrounding rocks were transformed into clay, whereas the fault gouge has more illite and less illite/montmorillonite mixed layers than the surrounding rocks, which shows that the illite/montmorillonite mixed layer was partly converted into illite due to temperature increasing induced by coseismic fault slipping friction (also being affected partly by the chemical action of solutions). Such microstructures features and mineral component changes recorded the information of fault slip and provide criterions for discussing the genesis of fault gouge and recognition of the direction of fault movement.

A study of the mixing state of black carbon in urban zone

NASA Astrophysics Data System (ADS)

Mallet, M.; Roger, J. C.; Despiau, S.; Putaud, J. P.; Dubovik, O.

2004-02-01

The knowledge of the mixing state of black carbon particle with other aerosol species is critical for adequate simulations of the direct radiative effect of black carbon particles and its effect on climate. This paper reports the investigation of the mixing state of black carbon aerosol in the urban zone. The study uses a combination of in situ and ground-based remote sensing observations conducted during the ESCOMPTE experiment, which took place in industrialized region in France in summer of 2001. The criteria we used for identifying mixing state relies on the known enhancement of absorption for aerosol composed by internal versus external mixtures of black carbon with weakly absorbing aerosol components. First, using in situ aerosol data, we performed Mie computations and reconstructed the single scattering albedo of aerosol for the two different mixing assumptions: black carbon mixed externally or internally with other aerosol species. Then, we compared the obtained values ωo,int and ωo,ext with the retrievals of ωo from independent AERONET Sun-photometric measurements. The aerosol single scattering albedo (ωo,aer.) derived from the AERONET photometer observations (with the mean value equal to 0.84 ± 0.04) was found to be close to ωo,ext reconstructed from in situ observation under assumptions of external mixture. This similarity between AERONET values and external mixture simulations was observed during all the days studied. Our conclusion on external mixture of black carbon aerosol with other particles in urban zone during ESCOMPTE (close to the pollution source) is coherent with observations made during other independent studies reported in a number of recent publications.

Experimental testing and modeling analysis of solute mixing at water distribution pipe junctions.

PubMed

Shao, Yu; Jeffrey Yang, Y; Jiang, Lijie; Yu, Tingchao; Shen, Cheng

2014-06-01

Flow dynamics at a pipe junction controls particle trajectories, solute mixing and concentrations in downstream pipes. The effect can lead to different outcomes of water quality modeling and, hence, drinking water management in a distribution network. Here we have investigated solute mixing behavior in pipe junctions of five hydraulic types, for which flow distribution factors and analytical equations for network modeling are proposed. First, based on experiments, the degree of mixing at a cross is found to be a function of flow momentum ratio that defines a junction flow distribution pattern and the degree of departure from complete mixing. Corresponding analytical solutions are also validated using computational-fluid-dynamics (CFD) simulations. Second, the analytical mixing model is further extended to double-Tee junctions. Correspondingly the flow distribution factor is modified to account for hydraulic departure from a cross configuration. For a double-Tee(A) junction, CFD simulations show that the solute mixing depends on flow momentum ratio and connection pipe length, whereas the mixing at double-Tee(B) is well represented by two independent single-Tee junctions with a potential water stagnation zone in between. Notably, double-Tee junctions differ significantly from a cross in solute mixing and transport. However, it is noted that these pipe connections are widely, but incorrectly, simplified as cross junctions of assumed complete solute mixing in network skeletonization and water quality modeling. For the studied pipe junction types, analytical solutions are proposed to characterize the incomplete mixing and hence may allow better water quality simulation in a distribution network. Published by Elsevier Ltd.

Flow analysis for efficient design of wavy structured microchannel mixing devices

NASA Astrophysics Data System (ADS)

Kanchan, Mithun; Maniyeri, Ranjith

2018-04-01

Microfluidics is a rapidly growing field of applied research which is strongly driven by demands of bio-technology and medical innovation. Lab-on-chip (LOC) is one such application which deals with integrating bio-laboratory on micro-channel based single fluidic chip. Since fluid flow in such devices is restricted to laminar regime, designing an efficient passive modulator to induce chaotic mixing for such diffusion based flow is a major challenge. In the present work two-dimensional numerical simulation of viscous incompressible flow is carried out using immersed boundary method (IBM) to obtain an efficient design for wavy structured micro-channel mixing devices. The continuity and Navier-Stokes equations governing the flow are solved by fractional step based finite volume method on a staggered Cartesian grid system. IBM uses Eulerian co-ordinates to describe fluid flow and Lagrangian co-ordinates to describe solid boundary. Dirac delta function is used to couple both these co-ordinate variables. A tether forcing term is used to impose the no-slip boundary condition on the wavy structure and fluid interface. Fluid flow analysis by varying Reynolds number is carried out for four wavy structure models and one straight line model. By analyzing fluid accumulation zones and flow velocities, it can be concluded that straight line structure performs better mixing for low Reynolds number and Model 2 for higher Reynolds number. Thus wavy structures can be incorporated in micro-channels to improve mixing efficiency.

Application of Microbeam Techniques to Identifying and Assessing Comagmatic Mixing Between Summit and Rift Eruptions at Kilauea Volcano (Invited)

NASA Astrophysics Data System (ADS)

Thornber, C. R.; Rowe, M. C.; Adams, D. T.; Orr, T. R.

2010-12-01

Near-continuous eruption of Kilauea Volcano since 1983 has yielded an extensive record of glass, phenocryst and melt-inclusion chemistry from well-quenched lava that can be correlated with geophysical and geological monitoring data. Eruption temperatures are determined using glass thermometry. Microbeam evaluation of phenocryst mineralogy, morphology, texture, zoning and melt inclusions helps to constrain magma storage and transport within the edifice and to track the evolution of shallow magmatic plumbing during this prolonged eruptive era. For most of this eruption up to April 2001, east rift lava was olivine-phyric and olivine-liquid relations indicated equilibrium crystallization during summit-to-rift magma transport. From 2001 to present, most lava erupted from vents near Pu`u O`o has been a relatively low-temperature “hybrid”, characterized by a disequilibrium low-pressure phenocryst assemblage. Olivine (Fo81.5-80.5) coexists with phenocrysts of lower temperature clinopyroxene (±plagioclase, ±Fe-rich olivine). Mixing between hotter and cooler magma is texturally documented by complex pyroxene zoning and resorption and olivine overgrowths on resorbed pyroxene. The co-magmatic mixing is not apparent in bulk lava analyses, since both components are fractionates of parent magmas with indistinguishable trace-element signatures. Post-2001 rift-zone lava indicates perpetual flushing of stored magma by hotter recharge magma rising from the mantle source. Geophysical and gas monitoring data confirm an increase in magma supply to Kilauea Volcano between 2001 and 2008, which we have interpreted as increasing the efficiency of the flushing process. Since March 2008, the petrology of the new summit lava lake and contemporaneously erupted rift zone lava provides new perspective on complexities of magma degassing, crystallization and mixing prior to rift eruption. Bulk lava chemistry, SIMS and LA-ICPMS analyses of matrix glasses and olivine melt-inclusions in both rift zone lava and summit tephra reveal identical trace-element concentrations, thus confirming that both eruption sites share a common magma source. Because Kilauea magma degasses all of its primary sulfur (~1200 to 1500 ppm) at pressures less than 100 bars, shallow summit-to-rift magma mixing and crystallization is quantified by study of relative sulfur concentrations in melt inclusions. For higher temperature magma at the summit, olivine (Fo82.0-83.5) contains melt inclusions with 600-1400 ppm S. A small population of rift zone phenocrysts have similar sulfur contents, while typical rift zone olivine inclusions contain 300-700 ppm S. Complex zoned pyroxene phenocrysts with multiple inclusions have trapped melts of low to high sulfur concentrations ranging from100 to 1000 ppm. Collectively, these microbeam observations provide evidence for dynamic pre-eruptive comingling between hotter, sulfur-rich magma rising beneath the summit with a denser, cooler and degassed pyroxene-bearing magma mush, prior to eruption on the east rift.

Fracture zones in the Mid Atlantic Ridge lead to alterations in prokaryotic and viral parameters in deep-water masses

PubMed Central

Muck, Simone; Griessler, Thomas; Köstner, Nicole; Klimiuk, Adam; Winter, Christian; Herndl, Gerhard J.

2014-01-01

We hypothesized that mixing zones of deep-water masses act as ecotones leading to alterations in microbial diversity and activity due to changes in the biogeochemical characteristics of these boundary systems. We determined the changes in prokaryotic and viral abundance and production in the Vema Fracture Zone (VFZ) of the subtropical North Atlantic Ocean, where North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) are funneled through this narrow canyon and therefore, are subjected to intense vertical mixing. Consequently, salinity, potential temperature, oxygen, PO4, SiO4, NO3 were altered in the NADW inside the VFZ as compared to the NADW outside of the VFZ. Also, viral abundance, lytic viral production (VP) and the virus-to-prokaryote ratio (VPR) were elevated in the NADW in the VFZ as compared to the NADW outside the VFZ. In contrast to lytic VP, lysogenic VP and both the frequency of lytically (FIC) and lysogenically infected cells (FLC) did not significantly differ between in- and outside the VFZ. Generally, FIC was higher than FLC throughout the water column. Prokaryotic (determined by T-RFLP) and viral (determined by RAPD-PCR) community composition was depth-stratified inside and outside the VFZ. The viral community was more modified both with depth and over distance inside the VFZ as compared to the northern section and to the prokaryotic communities. However, no clusters of prokaryotic and viral communities characteristic for the VFZ were identified. Based on our observations, we conclude that turbulent mixing of the deep water masses impacts not only the physico-chemical parameters of the mixing zone but also the interaction between viruses and prokaryotes due to a stimulation of the overall activity. However, only minor effects of deep water mixing were observed on the community composition of the dominant prokaryotes and viruses. PMID:24917857

Diversity and community composition of pico- and nanoplanktonic protists in the Vistula River estuary (Gulf of Gdańsk, Baltic Sea)

NASA Astrophysics Data System (ADS)

Piwosz, Kasia; Całkiewicz, Joanna; Gołębiewski, Marcin; Creer, Simon

2018-07-01

Pico- and nanoplanktonic protists (eukaryotic microorganisms with cell size of <3 μm and 3-20 μm, respectively) are the key component of plankton communities. However, their diversity and distribution patterns along environmental factors are still poorly recognized, largely due to their very large phylogenetic diversity that has been determined only via the application of molecular methods over the past two decades. Here, we compared diversity and composition of active communities of pico- and nanoplantonic protists from three zones of the Vistula River estuary (Gulf of Gdańsk): freshwater, mixing (salinity 3.5) and brackish (salinity 7), in four seasons, by pyrosequencing the V3-V4 fragment of 18S rRNA taxonomy marker gene libraries. Alpha diversity was the highest at the brackish site, but the OTU (Operational Taxonomic Units) richness was characteristic for specific protist groups at each site. The active protistan communities in the freshwater and mixing zones (salinity 0-3.5) were similar (sharing >72% of phylotypes) and included centric diatoms (Stephanodiscus minutulus), synurophytes from clades C, E and F, and cryptophytes. However, at salinity of 7 at the brackish site the communities were significantly different from those in freshwater/mixing zone, and showed higher contributions of Dinophyceae, Mamiellophyceae, Telonemia, and picobiliphytes. The high similarity between the freshwater and mixing site, as well as high dissimilarity of the brackish site was observed in all months, despite seasonal shifts in pico- and nanoplantonic protistan communities. Seventy five percent of the observed variability in the communities was explained by combinations of temperature, salinity, nutrients and geographical distance, indicating interplay between species sorting and mass effects in shaping the active protistan communities in the Vistula River estuary. Groups that were more active in freshwaters and the mixing zone seemed to be more affected by mass effects of mixing water masses, while those from the brackish site by environmental species sorting. Finally, we report, for the first time, presence of Radiolaria (Acantharea) from the Baltic Sea.

Spatial distributions of biogeochemical reactions in freshwater-saltwater mixing zones of sandy beach aquifers

NASA Astrophysics Data System (ADS)

Kim, K. H.; Michael, H. A.; Ullman, W. J.; Cai, W. J.

2017-12-01

Beach aquifers host biogeochemically dynamic mixing zones between fresh and saline groundwaters of contrasting origins, histories, and compositions. Seawater, driven up the beachface by waves and tides, infiltrates into the sand and meets the seaward-discharging fresh groundwater, creating and maintaining a highly reactive intertidal circulation cell well-defined by salinity. Seawater supplies oxygen and reactive carbon to the circulation cell, supporting biogeochemical reactions within the cell that transform and attenuate dissolved nutrient fluxes from terrestrial sources. We investigated the spatial distribution of chemical reaction zones within the intertidal circulation cell at Cape Shores, Lewes, Delaware. Porewater samples were collected from multi-level wells along a beach-perpendicular transect. Samples were analyzed for particulate carbon and reactive solutes, and incubated to obtain rates of oxic respiration and denitrification. High rates of oxic respiration were observed higher on the beach, in the landward freshwater-saline water mixing zone, where dissolved oxygen availability was high. Denitrification was dominant in lower areas of the beach, below the intertidal discharge point. High respiration rates did not correlate with particulate carbon concentrations entrained within porewater, suggesting that dissolved organic carbon or immobile particulate carbon trapped within the sediment can contribute to and alter bulk reactivity. A better understanding of the sources and sinks of carbon within the beach will improve our ability to predict nutrient fluxes to estuaries and oceans, aiding the management of coastal environments and ecosystems.

Oblimersen and Gemcitabine in Treating Patients With Advanced Solid Tumor or Lymphoma

ClinicalTrials.gov

2013-01-24

Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific

Evaluation of flow mixing in an ARID-HV algal raceway using statistics of temporal and spatial distribution of fluid particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Ben; Li, Peiwen; Waller, Peter

2015-02-27

This paper analyzes and evaluates the flow mixing in an open channel algal raceway for biofuel production. The flow mixing governs the frequency of how algae cells are exposed to sunlight, due to the fluid movement between the surface and the bottom of the algal raceway, thereby affecting algal growth rate. In this work, we investigated the flow mixing performance in a table-sized model of the High Velocity Algae Raceway Integrated Design (ARID-HV). Various geometries of the raceway channels and dams were considered in both the CFD analysis and experimental flowvisualization. In the CFD simulation, the pathlines of fluid particlesweremore » analyzed to obtain the distribution of the number of times that particles passed across a critical water depth, Dc, defined as a cycle count. In addition, the distribution of the time period fraction that the fluid particles stayed in the zones above and below Dc was recorded. Such information was used to evaluate the flow mixing in the raceway. The CFD evaluation of the flow mixing was validated using experimental flow visualization, which showed a good qualitative agreement with the numerical results. In conclusion, this CFD-based evaluation methodology is recommended for flow field optimization for open channel algal raceways, as well as for other engineering applications in which flow mixing is an important concern.« less

19 CFR 146.43 - Domestic status.

Code of Federal Regulations, 2010 CFR

2010-04-01

... mixed or combined with merchandise in another zone status, or (2) upon order of the Commissioner of Customs. When the Commissioner orders a permit to be required for domestic status merchandise, he may also... and repair material, to a zone, except upon order of the Commissioner of Customs. No application or...

Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis.

PubMed

Eggleton, Peter P; Dearborn, David S P; Lattanzio, John C

2006-12-08

Low-mass stars, approximately 1 to 2 solar masses, near the Main Sequence are efficient at producing the helium isotope 3He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of 3He with the predictions of both stellar and Big Bang nucleosynthesis. Here we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between the hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus, we are able to remove the threat that 3He production in low-mass stars poses to the Big Bang nucleosynthesis of 3He.

Determination of variability in leaf biomass densities of conifers and mixed conifers under different environmental conditions in the San Joaquin Valley air basin. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Temple, P.J.; Mutters, R.J.; Adams, C.

1995-06-01

Biomass sampling plots were established at 29 locations within the dominant vegetation zones of the study area. Estimates of foliar biomass were made for each plot by three independent methods: regression analysis on the basis of tree diameter, calculation of the amount of light intercepted by the leaf canopy, and extrapolation from branch leaf area. Multivariate regression analysis was used to relate these foliar biomass estimates for oak plots and conifer plots to several independent predictor variables, including elevation, slope, aspect, temperature, precipitation, and soil chemical characteristics.

Groundwater circulation and geochemistry of a karstified bank marginal fracture system, South Andros Island, Bahamas

NASA Astrophysics Data System (ADS)

Whitaker, Fiona F.; Smart, Peter L.

1997-10-01

On the east coast of South Andros Island, Bahamas, a major bank-marginal fracture system characterised by vertically extensive cavern systems (blue holes) is developed sub-parallel to the steep-sided deep-water re-entrant of the Tongue of the Ocean. In addition to providing a discharge route for meteoric, mixed and geochemically evolved saline groundwaters, a strong local circulation occurs along the fracture system. This generates enhanced vertical mixing within voids of the fracture system, evidenced by the increasing mixing zone thickness, and the thinning and increasing salinity of brackish lens waters from north to south along the fracture system. Furthermore, tidally driven pumping of groundwaters occurs between the fracture and adjacent carbonate aquifer affecting a zone up to 200 m either side of the fracture. The resultant mixing of groundwaters of contrasting salinity and PCO 2 within and along the fracture system and with the surrounding aquifer waters, together with bacterial oxidation of organic matter, generates significant potential for locally enhanced diagenesis. Undersaturation with respect to calcite within the fresh (or brackish)-salt water mixing zone is observed in the fracture system and predicted in the adjacent aquifer, while mixing between the brackish fracture lens and surrounding high PCO 2 fresh waters causes dissolution of aragonite but not calcite. The latter gives rise to considerable secondary porosity development, because active tidal pumping ensures continued renewal of dissolutional potential. This is evidenced by calcium and strontium enrichment in the brackish lens which indicates porosity generation by aragonite dissolution at a maximum rate of 0.35% ka -1, up to twice the average estimated for the fresh water lens. In contrast saline groundwaters are depleted in calcium relative to open ocean waters suggesting the formation of calcite cements. The development of a major laterally continuous cavernous fracture zone along the margin of the carbonate platform permits enhanced groundwater flow and mixing which may result in generation of a diagenetic `halo' at a scale larger than that generally recognised around syn-sedimentary fractures in fossil carbonates. This may be characterised by increased secondary porosity where a relative fall in sea-level results in exposure and formation of a meteoric groundwater system, or cementation by `marine' calcite both below this meteoric system, and where the bank surface is flooded by seawater.

Magma volumes and storage in the middle crust

NASA Astrophysics Data System (ADS)

Memeti, V.; Barnes, C. G.; Paterson, S. R.

2015-12-01

Quantifying magma volumes in magma plumbing systems is mostly done through geophysical means or based on volcanic eruptions. Detailed studies of plutons, however, are useful in revealing depths and evolving volumes of stored magmas over variable lifetimes of magma systems. Knowledge of the location, volume, and longevity of stored magma is critical for understanding where in the crust magmas attain their chemical signature, how these systems physically behave and how source, storage levels, and volcanoes are connected. Detailed field mapping, combined with single mineral geochemistry and geochronology of plutons, allow estimates of size and longevity of melt-interconnected magma batches that existed during the construction of magma storage sites. The Tuolumne intrusive complex (TIC) recorded a 10 myr magmatic history. Detailed maps of the major units in different parts of the TIC indicate overall smaller scale (cm- to <1 km) compositional variation in the oldest, outer Kuna Crest unit and mainly larger scale (>10 km) changes in the younger Half Dome and Cathedral Peak units. Mineral-scale trace element data from hornblende of granodiorites to gabbros from the Kuna Crest lobe show distinct hornblende compositions and zoning patterns. Mixed hornblende populations occur only at the transition to the main TIC. This compositional heterogeneity in the first 1-2 myr points to low volume magmatism resulting in smaller, discrete and not chemically interacting magma bodies. Trace element and Sr- and Pb-isotope data from growth zones of K-feldspar phenocrysts from the two younger granodiorites indicate complex mineral zoning, but general isotopic overlap, suggesting in-situ, inter-unit mixing and fractionation. This is supported by hybrid zones between units, mixing of zircon, hornblende, and K-feldspar populations and late leucogranites. Thus, magma body sizes increased later resulting in overall more homogeneous, but complexly mixing magma mushes that fractionated locally.

Groundwater withdrawal in randomly heterogeneous coastal aquifers

NASA Astrophysics Data System (ADS)

Siena, Martina; Riva, Monica

2018-05-01

We analyze the combined effects of aquifer heterogeneity and pumping operations on seawater intrusion (SWI), a phenomenon which is threatening coastal aquifers worldwide. Our investigation is set within a probabilistic framework and relies on a numerical Monte Carlo approach targeting transient variable-density flow and solute transport in a three-dimensional randomly heterogeneous porous domain. The geological setting is patterned after the Argentona river basin, in the Maresme region of Catalonia (Spain). Our numerical study is concerned with exploring the effects of (a) random heterogeneity of the domain on SWI in combination with (b) a variety of groundwater withdrawal schemes. The latter have been designed by varying the screen location along the vertical direction and the distance of the wellbore from the coastline and from the location of the freshwater-saltwater mixing zone which is in place prior to pumping. For each random realization of the aquifer permeability field and for each pumping scheme, a quantitative depiction of SWI phenomena is inferred from an original set of metrics characterizing (a) the inland penetration of the saltwater wedge and (b) the width of the mixing zone across the whole three-dimensional system. Our results indicate that the stochastic nature of the system heterogeneity significantly affects the statistical description of the main features of the seawater wedge either in the presence or in the absence of pumping, yielding a general reduction of toe penetration and an increase of the width of the mixing zone. Simultaneous extraction of fresh and saltwater from two screens along the same wellbore located, prior to pumping, within the freshwater-saltwater mixing zone is effective in limiting SWI in the context of groundwater resources exploitation.

Effects of digital countdown timer on intersection safety and efficiency: A systematic review.

PubMed

Fu, Chuanyun; Zhang, Yaping; Qi, Weiwei; Cheng, Shaowu

2016-01-01

To investigate the available evidence referring to the effectiveness of digital countdown timers (DCTs) in improving the safety and operational efficiency of signalized intersection. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines. Relevant literature was searched from electronic databases using key terms. Based on study selection and methodological quality assessment, 14 studies were included in the review. Findings of the studies were synthesized in a narrative analysis. Three types of DCT had different effects on intersection safety and operational efficiency. Green signal countdown timers (GSCTs) reduced red light violations, type I dilemma zone distributions, and rear-end collision likelihood but increased crossing after yellow onset and had mixed impacts on type II dilemma zone distributions and intersection capacity. In contrast, red signal countdown timers (RSCTs) increased intersection capacity, although their effectiveness in reducing red light violations dissipated over time. Likewise, continuous countdown timers (CCTs) significantly enhanced intersection capacity but had mixed influences on red light violations and crossing after yellow onset. Due to the limited and inconsistent evidence regarding DCTs' effects on intersection safety and efficiency, it is not sufficient to recommend any type of DCT to be installed at signalized intersections to improve safety and operational efficiency. Nevertheless, it is apparent that both RSCTs and CCTs enhance intersection capacity, though their impacts on intersection safety are unclear. Future studies need to further verify those anticipated safe and operational benefits of DCTs with enriched field observation data.

Observation and analysis of emergent coherent structures in a high-energy-density shock-driven planar mixing layer experiment

DOE PAGES

Doss, Forrest William; Flippo, Kirk Adler; Merritt, Elizabeth Catherine

2016-08-03

Coherent emergent structures have been observed in a high-energy-density supersonic mixing layer experiment. A millimeter-scale shock tube uses lasers to drive Mbar shocks into the tube volume. The shocks are driven into initially solid foam (60 mg/cm 3) hemicylinders separated by an Al or Ti metal tracer strip; the components are vaporized by the drive. Before the experiment disassembles, the shocks cross at the tube center, creating a very fast (ΔU > 200 km/s) shear-unstable zone. After several nanoseconds, an expanding mixing layer is measured, and after 10+ ns we observe the appearance of streamwise-periodic, spanwise-aligned rollers associated with themore » primary Kelvin-Helmholtz instability of mixing layers. We additionally image roller pairing and spanwise-periodic streamwise-aligned filaments associated with secondary instabilities. New closures are derived to connect length scales of these structures to estimates of fluctuating velocity data otherwise unobtainable in the high-energy-density environment. Finally, this analysis indicates shear-induced specific turbulent energies 10 3 – 10 4 times higher than the nearest conventional experiments. Because of difficulties in continuously driving systems under these conditions and the harshness of the experimental environment limiting the usable diagnostics, clear evidence of these developing structures has never before been observed in this regime.« less

Increasing FSW join strength by optimizing feed rate, rotating speed and pin angle

NASA Astrophysics Data System (ADS)

Darmadi, Djarot B.; Purnowidodo, Anindito; Siswanto, Eko

2017-10-01

Principally the join in Friction Stir Welding (FSW) is formed due to mechanical bonding. At least there are two factors determines the quality of this join, first is the temperature in the area around the interface and secondly the intense of mixing forces in nugget zone to create the mechanical bonding. The adequate temperature creates good flowability of the nugget zone and an intensive mixing force produces homogeneous strong bonding. Based on those two factors in this research the effects of feed rate, rotating speed and pin angle of the FSW process to the tensile strength of resulted join are studied. The true experimental method was used. Feed rate was varied at 24, 42, 55 and 74 mm/minutes and from the experimental results, it can be concluded that the higher feed rate decreases the tensile strength of weld join and it is believed due to the lower heat embedded in the material. Inversely, the higher rotating speed increases the join’s tensile strength as a result of higher heat embedded in base metal and higher mixing force in the nugget zone. The rotating speed were 1842, 2257 and 2904 RPMs. The pin angle determines the direction of mixing force. With variation of pin angle: 0°, 4°, 8° and 12° the higher pin angle generally increases the tensile strength because of more intensive mixing force. For 12° pin angle the lower tensile strength is found since the force tends to push out the nugget area from the joint gap.

Seasonal Stream Partitioning and Critical Zone Feedbacks within a Colorado River Headwater Basin

NASA Astrophysics Data System (ADS)

Carroll, R. W. H.; Bearup, L. A.; Williams, K. H.; Brown, W. S.; Dong, W.; Bill, M.

2017-12-01

Groundwater contribution to streams can modulate discharge response to climate extremes, thereby protecting ecosystem health and water supply for downstream users. However, much uncertainty exists on the role of groundwater contribution in snow-dominated, mountainous systems. To better understand seasonal stream source, we employ the empirical approach of end-member mixing analysis (EMMA) using a suite of natural chemical and isotopic observations within the East River; a headwater catchment of the Colorado River and recently designated as a Science Focus Area with Lawrence Berkeley National Laboratory. EMMA relies on principal component analysis to reduce the number of dimensions of variability (U-space) for use in hydrograph separation. The mixing model was constructed for the furthest downstream and most heavily characterized stream gauge in the study site (PH; 84.7 km2). Potential tracers were identified from PH discharge as near linear (Mg, Ca, Sr, U, SO4, DIC, δ2H and δ18O) with alternative groupings evaluated. The best model was able to describe 97% of the tracer variance in 2-dimensions with low error and lack of residual structure. U-space positioning resulted in seasonal stream water source contributions of rain (8-16%), snow (48-74%) and groundwater (18-42%). EMMA developed for PH did not scale across 10 nested sub-basins (ranging from 0.38 km2 to 69.9 km2). Differences in mixing ratios are attributable to feedbacks in the critical zone with a focus on (1) source rock contributions of SO4 and U; (2) biogeochemical processes of enhanced SO4 reduction in the floodplain sediments, (3) flow path length as expressed by carbonate weathering, and (4) enhanced groundwater contributions as related to snow distribution and ecosystem structure. EMMA is an initial step to elucidate source contributions to streamflow and address scalability and applicability of mixing processes in a complex, highly heterogeneous, snow-dominated catchment. Work will aid hydrologic conceptualization of the East River, guide future observation, and inform numerical model development over a range of scales and across key system subcomponents, such as hillslopes, floodplains, and deep groundwater.

Effect of fuel composition and differential diffusion on flame stabilization in reacting syngas jets in turbulent cross-flow

DOE PAGES

Minamoto, Yuki; Kolla, Hemanth; Grout, Ray W.; ...

2015-07-24

Here, three-dimensional direct numerical simulation results of a transverse syngas fuel jet in turbulent cross-flow of air are analyzed to study the influence of varying volume fractions of CO relative to H 2 in the fuel composition on the near field flame stabilization. The mean flame stabilizes at a similar location for CO-lean and CO-rich cases despite the trend suggested by their laminar flame speed, which is higher for the CO-lean condition. To identify local mixtures having favorable mixture conditions for flame stabilization, explosive zones are defined using a chemical explosive mode timescale. The explosive zones related to flame stabilizationmore » are located in relatively low velocity regions. The explosive zones are characterized by excess hydrogen transported solely by differential diffusion, in the absence of intense turbulent mixing or scalar dissipation rate. The conditional averages show that differential diffusion is negatively correlated with turbulent mixing. Moreover, the local turbulent Reynolds number is insufficient to estimate the magnitude of the differential diffusion effect. Alternatively, the Karlovitz number provides a better indicator of the importance of differential diffusion. A comparison of the variations of differential diffusion, turbulent mixing, heat release rate and probability of encountering explosive zones demonstrates that differential diffusion predominantly plays an important role for mixture preparation and initiation of chemical reactions, closely followed by intense chemical reactions sustained by sufficient downstream turbulent mixing. The mechanism by which differential diffusion contributes to mixture preparation is investigated using the Takeno Flame Index. The mean Flame Index, based on the combined fuel species, shows that the overall extent of premixing is not intense in the upstream regions. However, the Flame Index computed based on individual contribution of H 2 or CO species reveals that hydrogen contributes significantly to premixing, particularly in explosive zones in the upstream leeward region, i.e. at the preferred flame stabilization location. Therefore, a small amount of H 2 diffuses much faster than CO, creating relatively homogeneous mixture pockets depending on the competition with turbulent mixing. These pockets, together with high H 2 reactivity, contribute to stabilizing the flame at a consistent location regardless of the CO concentration in the fuel for the present range of DNS conditions.« less

Geochemical Characterization of Shallow and Deep Aquifer Mixing in the East Newport Mesa Area, Orange County, CA

NASA Astrophysics Data System (ADS)

Neel, B.; Hagedorn, B.; Xu, X.; Walker, J. C.

2016-12-01

Groundwater flow in the East Newport Mesa has not been extensively studied due to the lack of sufficiently deep production or monitoring wells in the area. In this study, a conceptual hydrogeologic model of the area is developed to characterize lateral and vertical flow patterns between the shallow-most semi-perched, semi-confined aquifer and the underlying regional, potable, confined aquifer. Groundwaters from 12 newly constructed monitoring wells throughout the region, screened at depths ranging from 6.5 to 110 meters below ground surface were sampled and analyzed once for 222Rn, 14C, 13C, 18O, and 2H, and one year quarterly for major ion composition. Additionally, water levels in each well were monitored weekly and adjacent surface waters were analyzed once for 222Rn activity. Geochemical analysis and groundwater level trends were used to test against a model developed based on correlation of downhole logs and known regional geologic structure from basin-wide reports. Major ion analysis revealed endmember groundwaters of NaHCO3, CaHCO3, and NaCl character, and others that fall along endmember mixing lines, while time-series data show that groundwaters in the shallow eastern-most portion of the mesa varied up to 20% in Ca:Na ratio throughout the year. 13C values range from -26.3 to -12.4‰, while 14C age dates range from 485 to 10,280 years before present, and in some cases show an age-inversion, where waters of younger apparent age lie below those of older. Groundwaters sampled throughout the mesa showed 222Rn values ranging from 8 to 1,501 pCi/L. A primary feature of the preliminary conceptual model is the presence of an aquifer mergence zone, i.e., an angular or erosional unconformity in which the intervening aquitard between the two zones is eroded away, thus hydraulically joining the two aquifers. Mixing patterns inferred by major ion data and asymptotic decay of 14C support the existence of a mergence zone and also highlight a potential seasonal intrusion of seawater from the Upper Newport Back Bay into the mesa. This conceptual model will potentially serve as the foundation for a numerical flow model, and related contaminant transport model, with implications for managing and protecting drinking water production wells in the Orange County Groundwater Basin.

Structure of hydrogen-rich transverse jets in a vitiated turbulent flow

DOE PAGES

Lyra, Sgouria; Wilde, Benjamin; Kolla, Hemanth; ...

2014-11-24

Our paper reports the results of a joint experimental and numerical study of the flow characteristics and flame structure of a hydrogen rich jet injected normal to a turbulent, vitiated crossflow of lean methane combustion products. Simultaneous high-speed stereoscopic PIV and OH PLIF measurements were obtained and analyzed alongside three-dimensional direct numerical simulations of inert and reacting JICF with detailed H2/COH2/CO chemistry. Both the experiment and the simulation reveal that, contrary to most previous studies of reacting JICF stabilized in low-to-moderate temperature air crossflow, the present conditions lead to a burner-attached flame that initiates uniformly around the burner edge. Significantmore » asymmetry is observed, however, between the reaction zones located on the windward and leeward sides of the jet, due to the substantially different scalar dissipation rates. The windward reaction zone is much thinner in the near field, while also exhibiting significantly higher local and global heat release than the much broader reaction zone found on the leeward side of the jet. The unsteady dynamics of the windward shear layer, which largely control the important jet/crossflow mixing processes in that region, are explored in order to elucidate the important flow stability implications arising in the inert and reacting JICF. The paper concludes with an analysis of the ignition, flame characteristics, and global structure of the burner-attached flame. FurthermoreChemical explosive mode analysis (CEMA) shows that the entire windward shear layer, and a large region on the leeward side of the jet, are highly explosive prior to ignition and are dominated by non-premixed flame structures after ignition. The predominantly mixing limited nature of the flow after ignition is examined by computing the Takeno flame index, which shows that ~70% of the heat release occurs in non-premixed regions.« less

Measurement of Refractive Index Gradients by Deflection of a Laser Beam

ERIC Educational Resources Information Center

Barnard, A. J.; Ahlborn, B.

1975-01-01

In this simple experiment for an undergraduate laboratory a laser beam is passed through the mixing zone of two liquids with different refractive indices. The spatial variation of the refractive index, at different times during the mixing, can be determined from the observed deflection of the beam. (Author)

Differentiation of chocolates according to the cocoa's geographical origin using chemometrics.

PubMed

Cambrai, Amandine; Marcic, Christophe; Morville, Stéphane; Sae Houer, Pierre; Bindler, Françoise; Marchioni, Eric

2010-02-10

The determination of the geographical origin of cocoa used to produce chocolate has been assessed through the analysis of the volatile compounds of chocolate samples. The analysis of the volatile content and their statistical processing by multivariate analyses tended to form independent groups for both Africa and Madagascar, even if some of the chocolate samples analyzed appeared in a mixed zone together with those from America. This analysis also allowed a clear separation between Caribbean chocolates and those from other origins. Height compounds (such as linalool or (E,E)-2,4-decadienal) characteristic of chocolate's different geographical origins were also identified. The method described in this work (hydrodistillation, GC analysis, and statistic treatment) may improve the control of the geographical origin of chocolate during its long production process.

A variable mixing-length ratio for convection theory

NASA Technical Reports Server (NTRS)

Chan, K. L.; Wolff, C. L.; Sofia, S.

1981-01-01

It is argued that a natural choice for the local mixing length in the mixing-length theory of convection has a value proportional to the local density scale height of the convective bubbles. The resultant variable mixing-length ratio (the ratio between the mixing length and the pressure scale height) of this theory is enhanced in the superadiabatic region and approaches a constant in deeper layers. Numerical tests comparing the new mixing length successfully eliminate most of the density inversion that typically plagues conventional results. The new approach also seems to indicate the existence of granular motion at the top of the convection zone.

Plasma-Based Mixing Actuation in Airflow, Quantitated by Probe Breakdown Fluorescence

NASA Astrophysics Data System (ADS)

Leonov, Sergey; Firsov, Alexander; Shurupov, Michail; Yarantsev, Dmitry; Ohio State University Team; JIHT RAS Team

2013-09-01

Effective mixing of fuel and oxidizer in air-breathing engine at compressible conditions is an essential problem of high-speed combustion due to short residence time of gas mixture in the combustor of limited length. The effect of the mixing actuation by plasma is observed because of the gasdynamic instability arisen after the long filamentary discharge of submicrosecond duration generated along the contact zone of two co-flown gases. The work is focused on detail consideration of the mechanism of gas instability, promoted by plasma, on effect of the discharge specific localization, and on diagnostics development for qualitative and quantitative estimation of the mixing efficiency. The dynamics of relative concentration of gas components is examined quantitatively by means of Probe Discharge Breakdown Fluorescence (PBF). In this method an optical emission spectra of weak filamentary high-voltage nanosecond probe discharge are collected from local zone of interest in airflow. The first measurements of the mixing efficiency in vicinity of wall-injected secondary gas are presented. It is shown that the method of PBF could deliver experimental data on state of the two-component medium with <1 mcs and <5 mm of time and spatial resolution, correspondingly. Funded by AFOSR under Dr Chiping Li supervision

Dynamics of tropical oxygen minium zones (OMZ): The role of vertical mixing and eddy stirring in ventilating the OMZ in the tropical Atlantic

NASA Astrophysics Data System (ADS)

Visbeck, M.; Banyte, D.; Brandt, P.; Dengler, M.; Fischer, T.; Karstensen, J.; Krahmann, G.; Tanhua, T. S.; Stramma, L.

2013-12-01

Equatorial Dynamics provide an essential influence on the ventilation pathways of well oxygenated surface water on their route to tropical oxygen minimum zones (OMZ). The large scale wind driven circulation shield OMZs from the direct ventilation pathways. They are located in the so called ';shadow zones' equator ward of the subtropical gyres. From what is known most of the oxygen is supplied via pathways from the western boundary modulated by the complex zonal equatorial current system and marginally by vertical mixing. What was less clear is which of the possible pathways are most effective in transporting dissolved oxygen towards the OMZ. A collaborative research program focused on the dynamics of oxygen minimum zones, called SFB754 "Climate - Biogeochemistry Interactions in the Tropical Ocean", allowed us to conduct two ocean tracer release experiments to investigate the vertical and horizontal mixing rates and associated oxygen transports. Specifically we report on the first deliberate tracer release experiment (GUTRE, Guinea Upwelling Tracer Release Experiment) in the tropical northeast Atlantic carried out in order to determine the diapycnal diffusivity coefficient in the upper layer of the OMZ. A tracer (CF3SF5) was injected in spring of 2008 and subsequently measured during three designated tracer survey cruises until the end of 2010. We found that, generally, the diffusivity is larger than expected for low latitudes and similar in magnitude to what has previously been experimentally determined in the Canary Basin. When combining the tracer study with estimates of diapycnal mixing based on microstructure profiling and a newly developed method using ship board ADCPs we were able to compute the vertical oxygen flux and its divergence for the OMZ. To our surprise, the vertical flux of oxygen by diapycnal mixing provides about 30% of the total ventilation. The estimate was derived from the simple advection-diffusion model taking into account moored and ship based velocity observations of the equatorial current systems along 23°W in the tropical Atlantic. However, the advective pathways are less certain and possibly more variable. Firstly, the strength of lateral eddy stirring and the role in oxygen transport is less well known, and is the focus of the ongoing second tracer release experiment (OSTRE, Oxygen Supply Tracer Release Experiment). Secondly, the analysis of historical data from the equatorial regime suggests that the observed decline in dissolved oxygen in the tropical North Atlantic might in part be a consequence of reduced horizontal ventilation by equatorial intermediate current systems. The uncertainty of the long-term variability of the circulation in the equatorial systems and additional uncertainty in the biogeochemical consumption rates provide a challenge for estimates of the future of the OMZ regimes. Model prediction of future oxygen changes depend on the models ability to reproduce the observed oxygen ventilation pathways and processes, which might limit the prediction's accuracy.

Estimation of bias with the single-zone assumption in measurement of residential air exchange using the perfluorocarbon tracer gas method.

PubMed

Van Ryswyk, K; Wallace, L; Fugler, D; MacNeill, M; Héroux, M È; Gibson, M D; Guernsey, J R; Kindzierski, W; Wheeler, A J

2015-12-01

Residential air exchange rates (AERs) are vital in understanding the temporal and spatial drivers of indoor air quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed air zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER(1z)). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER(2z)). In total, 287 daily pairs of AER(2z) and AER(1z) estimates were made from 35 homes across three cities. In 87% of the cases, AER(2z) was higher than AER(1z). Overall, the AER(1z) estimates underestimated AER(2z) by approximately 16% (IQR: 5-32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential air exchange using a single PFT gas, the assumption of a single well-mixed air zone very likely results in an under prediction of the AER. The results of this study suggest that the long-standing assumption that a home represents a single well-mixed air zone may result in a substantial negative bias in air exchange estimates. Indoor air quality professionals should take this finding into consideration when developing study designs or making decisions related to the recommendation and installation of residential ventilation systems. © 2014 Her Majesty the Queen in Right of Canada. Indoor Air published by John Wiley & Sons Ltd Reproduced with the permission of the Minister of Health Canada.

Simultaneous injection effective mixing flow analysis of urinary albumin using dye-binding reaction.

PubMed

Ratanawimarnwong, Nuanlaor; Ponhong, Kraingkrai; Teshima, Norio; Nacapricha, Duangjai; Grudpan, Kate; Sakai, Tadao; Motomizu, Shoji

2012-07-15

A new four-channel simultaneous injection effective mixing flow analysis (SIEMA) system has been assembled for the determination of urinary albumin. The SIEMA system consisted of a syringe pump, two 5-way cross connectors, four holding coils, five 3-way solenoid valves, a 50-cm long mixing coil and a spectrophotometer. Tetrabromophenol blue anion (TBPB) in Triton X-100 micelle reacted with albumin at pH 3.2 to form a blue ion complex with a λ(max) 625nm. TBPB, Triton X-100, acetate buffer and albumin standard solutions were aspirated into four individual holding coils by a syringe pump and then the aspirated zones were simultaneously pushed in the reverse direction to the detector flow cell. Baseline drift, due to adsorption of TBPB-albumin complex on the wall of the hydrophobic PTFE tubing, was minimized by aspiration of Triton X-100 and acetate buffer solutions between samples. The calibration graph was linear in the range of 10-50μg/mL and the detection limit for albumin (3σ) was 0.53μg/mL. The RSD (n=11) at 30μg/mL was 1.35%. The sample throughput was 37/h. With a 10-fold dilution, interference from urine matrix was removed. The proposed method has advantages in terms of simple automation operation and short analysis time. Copyright © 2012 Elsevier B.V. All rights reserved.

Autotrophic denitrification supported by biotite dissolution in crystalline aquifers: (2) transient mixing and denitrification dynamic during long-term pumping.

PubMed

Roques, Clément; Aquilina, Luc; Boisson, Alexandre; Vergnaud-Ayraud, Virginie; Labasque, Thierry; Longuevergne, Laurent; Laurencelle, Marc; Dufresne, Alexis; de Dreuzy, Jean-Raynald; Pauwels, Hélène; Bour, Olivier

2018-04-01

We investigated the mixing and dynamic of denitrification processes induced by long-term pumping in the crystalline aquifer of Ploemeur (Brittany, France). Hydrological and geochemical parameters have been continuously recorded over 15 boreholes in 5km 2 on a 25-year period. This extensive spatial and temporal monitoring of conservative as well as reactive compounds is a key opportunity to identify aquifer-scale transport and reactive processes in crystalline aquifers. Time series analysis of the conservative elements recorded at the pumped well were used to determine mixing fractions from different compartments of the aquifer on the basis of a Principal Component Analysis approach coupled with an end-member mixing analysis. We could reveal that pumping thus induces a thorough reorganization of fluxes known as capture, favoring infiltration and vertical fluxes in the recharge zone, and upwelling of deep and distant water at long-term time scales. These mixing fractions were then used to quantify the extent of denitrification linked to pumping. Based on the results from batch experiments described in a companion paper, our computations revealed that i) autotrophic denitrification processes are dominant in this context where carbon sources are limited, that ii) nitrate reduction does not only come from the oxidation of pyrite as classically described in previous studies analyzing denitrification processes in similar contexts, and that iii) biotite plays a critical role in sustaining the nitrate reduction process. Both nitrate reduction, sulfate production as well as fluor release ratios support the hypothesis that biotite plays a key role of electron donor in this context. The batch-to-site similarities support biotite availability and the role by bacterial communities as key controls of nitrate removal in such crystalline aquifers. However, the long term data monitoring also indicates that mixing and reactive processes evolve extremely slowly at the scale of the decade. Copyright © 2017 Elsevier B.V. All rights reserved.

Iodine I 131 Tositumomab and Fludarabine Phosphate in Treating Older Patients Who Are Undergoing an Autologous or Syngeneic Stem Cell Transplant for Relapsed or Refractory Non-Hodgkin's Lymphoma

ClinicalTrials.gov

2014-08-04

Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Splenic Marginal Zone Lymphoma; Waldenström Macroglobulinemia

Interleukin-12 in Treating Patients With Previously Treated Non-Hodgkin's Lymphoma or Hodgkin's Disease

ClinicalTrials.gov

2015-04-14

Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma; Waldenström Macroglobulinemia

CCI-779 in Treating Patients With Recurrent or Refractory B-Cell Non-Hodgkin's Lymphoma or Chronic Lymphocytic Leukemia

ClinicalTrials.gov

2014-05-07

B-cell Chronic Lymphocytic Leukemia; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Malignant Neoplasm; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Splenic Marginal Zone Lymphoma; Waldenström Macroglobulinemia

Dissolved carbon dynamics in the freshwater-saltwater mixing zone of a coastal river entering the Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

He, S.; Xu, Y. J.

2017-12-01

Estuaries play an important role in the dynamics of dissolved carbon from freshwater to marine systems. This study aims to determine how dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations change along an 88-km long estuarine river with salinity ranging from 0.02 to 29.50. The study is expected to elucidate which processes most likely control carbon dynamics in a freshwater-saltwater mixing system, and to evaluate the net metabolism of this estuary using mixing curves and stable isotope analyses. From November 2014 to February 2016, water samples were collected and in-situ measurements on ambient water conditions were performed during eighteen field trips at six sites from upstream to downstream of the Calcasieu River, which enters the Northern Gulf of Mexico in the southern United States. δ13CDIC and δ13CDOC were measured from May 2015 to February 2017 during five of the field trips. The DIC concentration and δ13CDIC increased rapidly with increasing salinity in the mixing zone. The DIC concentrations appeared to be largely influenced by conservative mixing. The δ13CDIC values were close to those suggested by the conservative mixing model for May 2015, June 2015 and November 2015, but lower than those for July 2015 and February 2016, suggesting that an estuarine river can fluctuate from a balanced to a heterotrophic system (i.e., production/respiration < 1) seasonally. Unlike the DIC longitudinal trend, the DOC concentrations in the river estuary decreased from upstream to downstream, but to a much smaller degree. This river estuary consistently showed depleted δ13CDOC values (-30.56‰ to -25.92‰), suggesting that the DOC source in the mixing zone was highly terrestrially derived. However, in this relatively small isotopic range, δ13CDOC alone has limitations in differentiating carbon produced by aquatic photosynthesis from carbon produced by terrestrial photosynthesis in a river-ocean continuum. These findings suggest that riverine dissolved carbon undergoes a rapid change in freshwater-saltwater mixing, and that these dynamics should be taken into account in carbon processing and budgeting in the world's estuarine systems.

Recent Advances in Hyporheic Zone Science

NASA Astrophysics Data System (ADS)

Hester, E. T.

2017-12-01

The hyporheic zone exists beneath and adjacent to streams and rivers where surface water and groundwater interact. It provides unique habitat for aquatic organisms, can buffer surface water temperatures, and can be highly reactive, processing nutrients and improving water quality. The hyporheic zone is the subject of considerable research and the past year in WRR witnessed important conceptual advances. A key focus was rigorous evaluation of mixing between surface water and groundwater that occurs within hyporheic sediments. Field observations indicate that greater mixing occurs in the hyporheic zone than in deeper groundwater, and this distinction has been explored by recent numerical modeling studies, but more research is needed to fully understand the causes. A commentary this year in WRR proposed that hyporheic mixing is enhanced by a combination of fluctuating boundary conditions and multiscale physical and chemical spatial heterogeneity but confirmation is left to future research. This year also witnessed the boundaries of knowledge pushed back in a number of other key areas. Field quantification of hyporheic exchange and reactions benefited from advances including the use and interpretation of high frequency nutrient sensors, actively heater fiber optic sensors, isotope tracers, and geophysical methods such as electrical resistivity imaging. Conceptual advances were made in understanding the effects of unsteady environmental conditions (e.g., tides and storms) and preferential flow on hyporheic processes. Finally, hyporheic science is being brought increasingly to bear on applied issues such as informing nutrient removal crediting for stream restoration practices, for example in the Chesapeake Bay watershed.

An Investigation of a Hybrid Mixing Model for PDF Simulations of Turbulent Premixed Flames

NASA Astrophysics Data System (ADS)

Zhou, Hua; Li, Shan; Wang, Hu; Ren, Zhuyin

2015-11-01

Predictive simulations of turbulent premixed flames over a wide range of Damköhler numbers in the framework of Probability Density Function (PDF) method still remain challenging due to the deficiency in current micro-mixing models. In this work, a hybrid micro-mixing model, valid in both the flamelet regime and broken reaction zone regime, is proposed. A priori testing of this model is first performed by examining the conditional scalar dissipation rate and conditional scalar diffusion in a 3-D direct numerical simulation dataset of a temporally evolving turbulent slot jet flame of lean premixed H2-air in the thin reaction zone regime. Then, this new model is applied to PDF simulations of the Piloted Premixed Jet Burner (PPJB) flames, which are a set of highly shear turbulent premixed flames and feature strong turbulence-chemistry interaction at high Reynolds and Karlovitz numbers. Supported by NSFC 51476087 and NSFC 91441202.

Pulverized coal burner

DOEpatents

Sivy, J.L.; Rodgers, L.W.; Koslosy, J.V.; LaRue, A.D.; Kaufman, K.C.; Sarv, H.

1998-11-03

A burner is described having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO{sub x} burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO{sub x} back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing. 8 figs.

Pulverized coal burner

DOEpatents

Sivy, Jennifer L.; Rodgers, Larry W.; Koslosy, John V.; LaRue, Albert D.; Kaufman, Keith C.; Sarv, Hamid

1998-01-01

A burner having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO.sub.x burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO.sub.x back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing.

A textural and compositional investigation on the source and timing of iron oxidation and titanium enrichment in high-pressure serpentinites

NASA Astrophysics Data System (ADS)

Crossley, R.; Evans, K. A.; Reddy, S.; Lester, G. W.

2016-12-01

The redox state, quantity and composition of subduction zone fluids influence the transport and precipitation of elements including those which are redox-sensitive, of economic importance such as Cu, Au and Ag, and those considered to be immobile, which include Fe3+. However, subduction zone fluids remain poorly understood. The redox state of Fe in high-pressure ultramafic rocks, which host a significant proportion of Fe3+, can be used to provide an insight into Fe cycling and constrain the composition and possible source of subduction zone fluids. In this work, we use a combination of oxide mineral textures, mineral parageneses, mineral composition data, and whole rock geochemistry of high-pressure retrogressed ultramafic rocks from the Zermatt-Saas Zone to constrain the distribution and oxidation state of iron, and to provide insights on the nature of fluids at depth within subduction zones. Oxide minerals host the bulk of the iron, particularly Fe3+. The increase in mode of magnetite during initial retrogression is most consistent with oxidation of existing iron via the infiltration of an oxidising fluids since it is difficult to reconcile addition of Fe3+ with the known limited solubility of this species. In addition, fluid-mediated or mechanical mixing with other lithologies in the slab could introduce elements and alter the bulk composition of serpentinites. However, the high Ti content of one sample cannot be explained by simple mixing of a depleted mantle protolith with the nearby Allalin gabbros, and provides the tantalising possibility that Ti, an element generally perceived as immobile, has been added to the rock. While we cannot completely exclude the possibility of pre-subduction Ti addition, textural analysis of Ti-rich minerals suggest mobilisation of Ti during subduction on at least a centimetre scale. If Ti addition has occurred, then the introduction of Fe3+, also generally considered to be immobile, cannot be disregarded. The Al-rich nature of the sample may be consistent with aluminosilicate complexing as the transport vector for Ti and/or Fe3+.

Physical and thermal strain of firefighters according to the firefighting tactics used to suppress wildfires.

PubMed

Rodríguez-Marroyo, J A; Villa, J G; López-Satue, J; Pernía, R; Carballo, B; García-López, J; Foster, C

2011-11-01

The aim of this study was to analyse the physiological strain of firefighters, using heart rate (HR) and core temperature, during real wildfire suppression according to the type of attack performed (direct, indirect or mixed). Three intensity zones were established according to the HR corresponding to the ventilatory threshold (VT) and respiratory compensation threshold (RCT): zone 1, RCT. The exercise workload (training impulse (TRIMP)), the physiological strain index (PSI) and the cumulative heat strain index(CHSI) were calculated using the time spent in each zone, and the HR and core temperature, respectively. Significantly higher mean HR, time spent in Z2 and Z3 and TRIMP h(-1) were found in direct and mixed versus indirect attacks. The highest PSI and CHSI were observed in the direct attack. In conclusion, exercise strain and combined thermal strain, but not core temperature during wildfire suppression, are related to the type of attack performed. STATEMENT OF RELEVANCE: Our findings demonstrated that wildfire firefighting is associated with high physiological demands, which vary significantly depending on the tactics chosen for performing the task. These results should be kept in mind when planning programmes to improve wildland firefighters' physical fitness, which will allow improvement in their performance.

Convective mixing of air in firn at four polar sites

NASA Astrophysics Data System (ADS)

Kawamura, Kenji; Severinghaus, Jeffrey P.; Ishidoya, Shigeyuki; Sugawara, Satoshi; Hashida, Gen; Motoyama, Hideaki; Fujii, Yoshiyuki; Aoki, Shuji; Nakazawa, Takakiyo

2006-04-01

Air withdrawn from the firn at four polar sites (Dome Fuji, H72 and YM85, Antarctica and North GRIP, Greenland) was measured for δ15N of N 2 and δ18O of O 2 to test for the presence of convective air mixing in the top part of the firn, known as the "convective zone". Understanding the convective zone and its possible relationship to surface conditions is important for constructing accurate ice-core greenhouse gas chronologies and their phasing with respect to climate change. The thickness of the convective zone was inferred from a regression line with barometric slope of the data in the deep firn. It is less than a few meters at H72 and NGRIP, whereas a substantial convective zone is found at Dome Fuji (8.6 ± 2.6 m) and YM85 (14.0 ± 1.8 m). By matching the outputs of a diffusion model to the data, effective eddy diffusivities required to mix the firn air are found. At the surface of Dome Fuji and YM85, these are found to be several times greater than the molecular diffusivity in free air. The crossover from dominance of convection to molecular diffusion takes place at 7 ± 2, 11 ± 2 and 0.5 ± 0.5 m at Dome Fuji, YM85 and NGRIP, respectively. These depths can be used as an alternative definition of the convective zone thickness. The firn permeability at Dome Fuji is expected to be high because of intense firn metamorphism due to the low accumulation rate and large seasonal air temperature variation at the site. The firn layers in the top several meters are exposed to strong temperature gradients for several decades, leading to large firn grains and depth hoar that enhance permeability. The thick convective zone at YM85 is unexpected because the temperature, accumulation rate and near-surface density are comparable to NGRIP. The strong katabatic wind at YM85 is probably responsible for creating the deep convection. The largest convective zone found in this study is still only half of the current inconsistency implied from the deep ice core gas isotopes and firn densification models.

Linkages among geophysical facies, microbial composition, biogeochemical rates, and seasonal hydrology in the hyporheic zone

NASA Astrophysics Data System (ADS)

Stegen, J.

2016-12-01

The hyporheic zone is a critical ecosystem transition that links terrestrial, aquatic, and subsurface domains. To understand connections among physical, microbial, and biogeochemical components of the hyporheic zone, we obtained freeze cores along the Columbia River in the Hanford 300 Area and performed geologic, molecular, and microbial assays. Mud and sand content were found to be the primary drivers of microbial community attributes (in particular, of nitrite and carbon oxidizers). Microbial community analysis revealed an abundance of nitrifying Archaea (Thaumarchaea) and an absence of nitrifiying Bacteria. Network analysis revealed significant negative correlations between sand content and some statistical modules of microbial taxa, perhaps indicating the importance of pore water residence time on community composition. A similar set of microbial modules was positively correlated with total organic carbon. One such module that also positively correlated with aerobic metabolic rates was dominated by Thaumarchaea and Nitrospira, suggesting that ammonia oxidation was the dominant aerobic process. We also examined temporal changes in hyporheic microbial structure and activity through repeated sampling of attached and pore water microbes across a spatial gradient. We found that microbial communities remained distinct in river, hyporheic, and inland zones across seasonal variation in hydrologic mixing conditions. One reason was temperature-driven increases in microbial species richness in the hyporheic zone. We show that the relative importance of ecological selection and dispersal varied across environments and across geographic zones. Our results also indicated that while selection imposed short-term constraints on microbial community structure, hyporheic sediment communities did not respond to short-term hydrologic variation. Importantly, we demonstrated that the influence of selective pressures varied with phylogenetic affiliation, which may have been responsible for seasonal increases in Thaumarchaea and aerobic activity. Our results elucidate spatiotemporal shifts in composition and activity of hyporheic microbes across sedimentary and seasonal gradients in pore water environments that correlate with the contribution of Thaumarchaea to aerobic processes.

Selective transport of palynomorphs in marine turbiditic deposits: An example from the Ascension-Monterey Canyon system offshore central California

USGS Publications Warehouse

McGann, Mary

2017-01-01

The pollen assemblage of a deep-sea core (15G) collected at lower bathyal depths (3491 m) on a levee of Monterey Canyon off central California was investigated to gain insights into the delivery processes of terrigenous material to submarine fans and the effect this transport has on the palynological record. Thirty-two samples were obtained down the length of the core, 19 from hemipelagic and mixed mud deposits considered to be the background record, and 13 others from displaced flow deposits. The pollen record obtained from the background samples documents variations in the terrestrial flora as it adapted to changing climatic conditions over the last 19,000 cal yrs BP. A Q-mode cluster analysis defined three pollen zones: a Glacial Pollen Zone (ca. 20,000–17,000 cal yr BP), an overlying Transitional Pollen Zone (ca. 17,000–11,500 cal yr BP), and an Interglacial Pollen Zone (ca. 11,500 cal yr BP to present). Another Q-mode cluster analysis, of both the background mud and flow deposits, also defined these three pollen zones, but four of the 13 turbiditic deposits were assigned to pollen zones older than expected by their stratigraphic position. This was due to these samples containing statistically significant fewer palynomorphs than the background muds as well as being enriched (∼10–35% in some cases) in hydraulically-efficient Pinus pollen. A selective bias in the pollen assemblage, such as demonstrated here, may result in incorrect interpretations (e.g., climatic shifts or environmental perturbations) based on the floral record, indicating turbiditic deposits should be avoided in marine palynological studies. Particularly in the case of fine-grained flow deposits that may not be visually distinct, granulometry and grain size frequency distribution curves may not be enough to identify these biased deposits. Determining the relative abundance and source of displaced shallow-water benthic foraminifera entrained in these sediments serves as an excellent additional tool to do so.

Using heat as a tracer to estimate spatially distributed mean residence times in the hyporheic zone

NASA Astrophysics Data System (ADS)

Naranjo, R. C.; Pohll, G. M.; Stone, M. C.; Niswonger, R. G.; McKay, W. A.

2013-12-01

Biogeochemical reactions that occur in the hyporheic zone are highly dependent on the time solutes are in contact with riverbed sediments. In this investigation, we developed a two-dimensional longitudinal flow and solute transport model to estimate the spatial distribution of mean residence time in the hyporheic zone along a riffle-pool sequence to gain a better understanding of nitrogen reactions. A flow and transport model was developed to estimate spatially distributed mean residence times and was calibrated using observations of temperature and pressure. The approach used in this investigation accounts for the mixing of ages given advection and dispersion. Uncertainty of flow and transport parameters was evaluated using standard Monte-Carlo analysis and the generalized likelihood uncertainty estimation method. Results of parameter estimation indicate the presence of a low-permeable zone in the riffle area that induced horizontal flow at shallow depth within the riffle area. This establishes shallow and localized flow paths and limits deep vertical exchange. From the optimal model, mean residence times were found to be relatively long (9 - 40 days). The uncertainty of hydraulic conductivity resulted in a mean interquartile range of 13 days across all piezometers and was reduced by 24% with the inclusion of temperature and pressure observations. To a lesser extent, uncertainty in streambed porosity and dispersivity resulted in a mean interquartile range of 2.2- and 4.7 days, respectively. Alternative conceptual models demonstrate the importance of accounting for the spatial distribution of hydraulic conductivity in simulating mean residence times in a riffle-pool sequence. It is demonstrated that spatially variable mean residence time beneath a riffle-pool system does not conform to simple conceptual models of hyporheic flow through a riffle-pool sequence. Rather, the mixing behavior between the river and the hyporheic flow are largely controlled by layered heterogeneity and anisotropy of the subsurface.

Long-term mass transfer and mixing-controlled reactions of a DNAPL plume from persistent residuals

NASA Astrophysics Data System (ADS)

Liu, Yuan; Illangasekare, Tissa H.; Kitanidis, Peter K.

2014-02-01

Understanding and being able to predict the long-term behavior of DNAPL (i.e., PCE and TCE) residuals after active remediation has ceased have become increasingly important as attention at many sites turns from aggressive remediation to monitored natural attenuation and long-term stewardship. However, plume behavior due to mass loading and reactions during these later phases is less studied as they involve large spatial and temporal scales. We apply both theoretical analysis and pore-scale simulations to investigate mass transfer from DNAPL residuals and subsequent reactions within the generated plume, and, in particular, to show the differences between early- and late-time behaviors of the plume. In the zone of entry of the DNAPL entrapment zone where the concentration boundary layer in the flowing groundwater has not fully developed, the pore-scale simulations confirm the past findings based on laboratory studies that the mass transfer increases as a power-law function of the Peclét number, and is enhanced due to reactions in the plume. Away from the entry zone and further down gradient, the long-term reactions are limited by the available additive and mixing in the porous medium, thereby behave considerably differently from the entry zone. For the reaction between the contaminant and an additive with intrinsic second-order bimolecular kinetics, the late-time reaction demonstrates a first-order decay macroscopically with respect to the mass of the limiting additive, not with respect to that of the contaminant. The late-time decay rate only depends on the intrinsic reaction rate and the solubility of the entrapped DNAPL. At the intermediate time, the additive decays exponentially with the square of time (t2), instead of time (t). Moreover, the intermediate decay rate also depends on the initial conditions, the spatial distribution of DNAPL residuals, and the effective dispersion coefficient.

Solute Transport Dynamics in a Large Hyporheic Corridor System

NASA Astrophysics Data System (ADS)

Zachara, J. M.; Chen, X.; Murray, C. J.; Shuai, P.; Rizzo, C.; Song, X.; Dai, H.

2016-12-01

A hyporheic corridor is an extended zone of groundwater surface water-interaction that occurs within permeable aquifer sediments in hydrologic continuity with a river. These systems are dynamic and tightly coupled to river stage variations that may occur over variable time scales. Here we describe the behavior of a persistent uranium (U) contaminant plume that exists within the hyporheic corridor of a large, managed river system - the Columbia River. Temporally dense monitoring data were collected for a two year period from wells located within the plume at varying distances up to 400 m from the river shore. Groundwater U originates from desorption of residual U in the lower vadose zone during periods of high river stage and associated elevated water table. U is weakly adsorbed to aquifer sediments because of coarse texture, and along with specific conductance, serves as a tracer of vadose zone source terms, solute transport pathways, and groundwater-surface water mixing. Complex U concentration and specific conductance trends were observed for all wells that varied with distance from the river shoreline and the river hydrograph, although trends for each well were generally repeatable for each year during the monitoring period. Statistical clustering analysis was used to identify four groups of wells that exhibited common trends in dissolved U and specific conductance. A flow and reactive transport code, PFLOTRAN, was implemented within a hydrogeologic model of the groundwater-surface water interaction zone to provide insights on hydrologic processes controlling monitoring trends and cluster behavior. The hydrogeologic model was informed by extensive subsurface characterization, with the spatially variable topography of a basal aquitard being one of several key parameters. Numerical tracer experiments using PFLOTRAN revealed the presence of temporally complex flow trajectories, spatially variable domains of groundwater - river water mixing, and locations of enhanced groundwater - river exchange that helped to explain monitoring trends. Observations and modeling results are integrated into a conceptual model of this highly complex and dynamic system with applicability to hyporheic corridor systems elsewhere.

A zonal computational procedure adapted to the optimization of two-dimensional thrust augmentor inlets

NASA Technical Reports Server (NTRS)

Lund, T. S.; Tavella, D. A.; Roberts, L.

1985-01-01

A viscous-inviscid interaction methodology based on a zonal description of the flowfield is developed as a mean of predicting the performance of two-dimensional thrust augmenting ejectors. An inviscid zone comprising the irrotational flow about the device is patched together with a viscous zone containing the turbulent mixing flow. The inviscid region is computed by a higher order panel method, while an integral method is used for the description of the viscous part. A non-linear, constrained optimization study is undertaken for the design of the inlet region. In this study, the viscous-inviscid analysis is complemented with a boundary layer calculation to account for flow separation from the walls of the inlet region. The thrust-based Reynolds number as well as the free stream velocity are shown to be important parameters in the design of a thrust augmentor inlet.

Riparian control of stream-water chemistry: Implications for hydrochemical basin models

USGS Publications Warehouse

Hooper, R.P.; Aulenbach, Brent T.; Burns, Douglas A.; McDonnell, J.; Freer, J.; Kendall, C.; Beven, K.

1998-01-01

End-member mixing analysis has been used to determine the hydrological structure for basin hydrochemical models at several catchments. Implicit in this use is the assumption that controlling end members have been identified, and that these end members represent distinct landscape locations. At the Panola Mountain Research Watershed, the choice of controlling end members was supported when a large change in the calcium and sulphate concentration of one of the end members was reflected in the stream water. More extensive sampling of groundwater and soil water indicated, however, that the geographic extent of the contributing end members was limited to the riparian zone. Hillslope solutions were chemically distinct from the riparian solutions and did not appear to make a large contribution to streamflow. The dominant control of the riparian zone on stream-water chemistry suggests that hydrological flow paths cannot be inferred from stream-water chemical dynamics.

CALIBRATION OF THE MIXING-LENGTH THEORY FOR CONVECTIVE WHITE DWARF ENVELOPES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tremblay, P.-E.; Ludwig, H.-G.; Freytag, B.

2015-02-01

A calibration of the mixing-length parameter in the local mixing-length theory (MLT) is presented for the lower part of the convection zone in pure-hydrogen-atmosphere white dwarfs. The parameterization is performed from a comparison of three-dimensional (3D) CO5BOLD simulations with a grid of one-dimensional (1D) envelopes with a varying mixing-length parameter. In many instances, the 3D simulations are restricted to the upper part of the convection zone. The hydrodynamical calculations suggest, in those cases, that the entropy of the upflows does not change significantly from the bottom of the convection zone to regions immediately below the photosphere. We rely on thismore » asymptotic entropy value, characteristic of the deep and adiabatically stratified layers, to calibrate 1D envelopes. The calibration encompasses the convective hydrogen-line (DA) white dwarfs in the effective temperature range 6000 ≤ T {sub eff} (K) ≤15, 000 and the surface gravity range 7.0 ≤ log g ≤ 9.0. It is established that the local MLT is unable to reproduce simultaneously the thermodynamical, flux, and dynamical properties of the 3D simulations. We therefore propose three different parameterizations for these quantities. The resulting calibration can be applied to structure and envelope calculations, in particular for pulsation, chemical diffusion, and convective mixing studies. On the other hand, convection has no effect on the white dwarf cooling rates until there is a convective coupling with the degenerate core below T {sub eff} ∼ 5000 K. In this regime, the 1D structures are insensitive to the MLT parameterization and converge to the mean 3D results, hence they remain fully appropriate for age determinations.« less

Evidence for magma mixing within the Laacher See magma chamber (East Eifel, Germany)

USGS Publications Warehouse

Worner, G.; Wright, T.L.

1984-01-01

The final pyroclastic products of the late Quaternary phonolitic Laacher See volcano (East Eifel, W.-Germany) range from feldspar-rich gray phonolite to dark olivine-bearing rocks with variable amounts of feldspar and Al-augite megacrysts. Petrographically and chemically homogeneous clasts occur along with composite lapilli spanning the compositional range from phonolite (MgO 0.9%) to mafic hybrid rock (MgO 7.0%) for all major and trace elements. Both a basanitic and a phonolitic phenocryst paragenesis occur within individual clasts. The phonolite-derived phenocrysts are characterized by glass inclusions of evolved composition, rare inverse zoning and strong resorption indicating disequilibrium with the mafic hybrid matrix. Basanitic (magnesian) clinopyroxene and olivine, in contrast, show skeletal (normally zoned) overgrowths indicative of post-mixing crystallization. In accord with petrographical and other chemical evidence, mass balance calculations suggest mixing of an evolved Laacher See phonolite containing variable amounts of mineral cumulates and a megacryst-bearing basanite magma. Magma mixing occurred just prior to eruption (hours) of the lowermost magma layer of the Laacher See magma chamber but did not trigger the volcanic activity. ?? 1984.

Deep Mixing of 3He: Reconciling Big Bang and Stellar Nucleosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eggleton, P P; Dearborn, D P; Lattanzio, J

2006-07-26

Low-mass stars, {approx} 1-2 solar masses, near the Main Sequence are efficient at producing {sup 3}He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of {sup 3}He with the predictions of both stellar and Big Bang nucleosynthesis. In this paper we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between themore » hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus we are able to remove the threat that {sup 3}He production in low-mass stars poses to the Big Bang nucleosynthesis of {sup 3}He.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chong

We present a simple approach for determining ion, electron, and radiation temperatures of heterogeneous plasma-photon mixtures, in which temperatures depend on both material type and morphology of the mixture. The solution technique is composed of solving ion, electron, and radiation energy equations for both mixed and pure phases of each material in zones containing random mixture and solving pure material energy equations in subdivided zones using interface reconstruction. Application of interface reconstruction is determined by the material configuration in the surrounding zones. In subdivided zones, subzonal inter-material energy exchanges are calculated by heat fluxes across the material interfaces. Inter-material energymore » exchange in zones with random mixtures is modeled using the length scale and contact surface area models. In those zones, inter-zonal heat flux in each material is determined using the volume fractions.« less

Assessing the concentration, speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine, Vermont, USA

USGS Publications Warehouse

Balistrieri, L.S.; Seal, R.R.; Piatak, N.M.; Paul, B.

2007-01-01

The authors determine the composition of a river that is impacted by acid-mine drainage, evaluate dominant physical and geochemical processes controlling the composition, and assess dissolved metal speciation and toxicity using a combination of laboratory, field and modeling studies. Values of pH increase from 3.3 to 7.6 and the sum of dissolved base metal (Cd + Co + Cu + Ni + Pb + Zn) concentrations decreases from 6270 to 100 ??g/L in the dynamic mixing and reaction zone that is downstream of the river's confluence with acid-mine drainage. Mixing diagrams and PHREEQC calculations indicate that mixing and dilution affect the concentrations of all dissolved elements in the reach, and are the dominant processes controlling dissolved Ca, K, Li, Mn and SO4 concentrations. Additionally, dissolved Al and Fe concentrations decrease due to mineral precipitation (gibbsite, schwertmannite and ferrihydrite), whereas dissolved concentrations of Cd, Co, Cu, Ni, Pb and Zn decrease due to adsorption onto newly formed Fe precipitates. The uptake of dissolved metals by aquatic organisms is dependent on the aqueous speciation of the metals and kinetics of complexation reactions between metals, ligands and solid surfaces. Dissolved speciation of Cd, Cu, Ni and Zn in the mixing and reaction zone is assessed using the diffusive gradients in thin films (DGT) technique and results of speciation calculations using the Biotic Ligand Model (BLM). Data from open and restricted pore DGT units indicate that almost all dissolved metal species are inorganic and that aqueous labile or DGT available metal concentrations are generally equal to total dissolved concentrations in the mixing zone. Exceptions occur when labile metal concentrations are underestimated due to competition between H+ and metal ions for Chelex-100 binding sites in the DGT units at low pH values. Calculations using the BLM indicate that dissolved Cd and Zn species in the mixing and reaction zone are predominantly inorganic, which is consistent with the DGT results. Although the DGT method indicates that the majority of aqueous Cu species are inorganic, BLM calculations indicate that dissolved Cu is inorganic at pH 5.5. Integrated dissolved labile concentrations of Cd, Cu and Zn in the mixing and reaction zone are compared to calculated acute toxicity concentrations (LC50 values) for fathead minnows (Pimephales promelas) (Cd, Cu and Zn) and water fleas (Ceriodaphnia dubia) (Cd and Cu) using the BLM, and to national recommended water quality criteria [i.e., criteria maximum concentration (CMC) and criterion continuous concentration (CCC)]. Observed labile concentrations of Cd and Zn are below LC50 values and CMC for Cd, but above CCC and CMC for Zn at sites <30 m downstream of the confluence. In contrast, labile Cu concentrations exceed LC50 values for the organisms as well as CCC and CMC at sites <30 m downstream of the confluence. These results suggest that environmental conditions at sites closest to the confluence of the river and acid-mine drainage should not support healthy aquatic organisms. ?? 2007 Elsevier Ltd. All rights reserved.

Control of topography gradients on residence time distributions, mixing dynamics and reactive hotspot development

NASA Astrophysics Data System (ADS)

Bandopadhyay, Aditya; Le Borgne, Tanguy; Davy, Philippe

2017-04-01

Topography-driven subsurface flows are thought to play a central role in determining solute turnover and biogeochemical processes at different scales in the critical zone, including river-hyporheic zone exchanges, hillslope solute transport and reactions, and catchment biogeochemical cycles. Hydraulic head gradients, induced by topography gradients at different scales, generate a distribution of streamlines at depth, dictating the spatial distribution of redox sensitive species, the magnitude of surface water - ground water exchanges and ultimately the source/sink function of the subsurface. Flow velocities generally decrease with depth, leading to broad residence time distributions, which have been shown to affect river chemistry and geochemical reactions in catchments. In this presentation, we discuss the impact of topography-driven flows on mixing processes and the formation of localized reactive hotspots. For this, we solve analytically the coupled flow, mixing and reaction equations in two-dimensional vertical cross-sections of subsurface domains with different topography gradients. For a given topography gradient, we derive the spatial distribution of subsurface velocities, the rates of solute mixing accross streamlines and the induced kinetics of redox, precipitation and dissolution reactions using a Lagrangian approach (Le Borgne et al. 2014). We demonstrate that vertical velocity profiles driven by topography variations, act effectively as shear flows, hence stretching continuously the mixing fronts between recently infiltrated and resident water (Bandopadhyay et al. 2017). We thus derive analytical expressions for residence time distributions, mixing rates and kinetics of chemical reactions as a function of the topography gradients. We show that the rates dissolution and precipitation reactions are significantly enhanced by the existence of vertical velocity gradients and that reaction rates reach a maximum in a localized subsurface reactive layer, whose location and intensity depends on topography gradients. As a consequence of these findings, we discuss the links between topography variations, subsurface velocity gradients and biogeochemical processes in the critical zone. References: Bandopadhyay A., T. Le Borgne, Y. Méheust and M. Dentz (2017) Enhanced reaction kinetics and reactive mixing scale dynamics in mixing fronts under shear flow for arbitrary Damkohler numbers, Adv. in Water Resour. Vol. 100, p. 78-95 Le Borgne T., T. Ginn and M. Dentz (2014) Impact of Fluid Deformation on Mixing-Induced Chemical Reactions in Heterogeneous Flows, Geophys. Res. Lett., Vol. 41, 22, p. 7898-790

Towards Understanding Soil Forming in Santa Clotilde Critical Zone Observatory: Modelling Soil Mixing Processes in a Hillslope using Luminescence Techniques

NASA Astrophysics Data System (ADS)

Sanchez, A. R.; Laguna, A.; Reimann, T.; Giráldez, J. V.; Peña, A.; Wallinga, J.; Vanwalleghem, T.

2017-12-01

Different geomorphological processes such as bioturbation and erosion-deposition intervene in soil formation and landscape evolution. The latter processes produce the alteration and degradation of the materials that compose the rocks. The degree to which the bedrock is weathered is estimated through the fraction of the bedrock which is mixing in the soil either vertically or laterally. This study presents an analytical solution for the diffusion-advection equation to quantify bioturbation and erosion-depositions rates in profiles along a catena. The model is calibrated with age-depth data obtained from profiles using the luminescence dating based on single grain Infrared Stimulated Luminescence (IRSL). Luminescence techniques contribute to a direct measurement of the bioturbation and erosion-deposition processes. Single-grain IRSL techniques is applied to feldspar minerals of fifteen samples which were collected from four soil profiles at different depths along a catena in Santa Clotilde Critical Zone Observatory, Cordoba province, SE Spain. A sensitivity analysis is studied to know the importance of the parameters in the analytical model. An uncertainty analysis is carried out to stablish the better fit of the parameters to the measured age-depth data. The results indicate a diffusion constant at 20 cm in depth of 47 (mm2/year) in the hill-base profile and 4.8 (mm2/year) in the hilltop profile. The model has high uncertainty in the estimation of erosion and deposition rates. This study reveals the potential of luminescence single-grain techniques to quantify pedoturbation processes.

Liquid–liquid mixing studies in annular centrifugal contactors comparing stationary mixing vane options

DOE PAGES

Wardle, Kent E.

2015-09-11

Comparative studies of multiphase operation of an annular centrifugal contactor show the impact of housing stationary mixing vane configuration. A number of experimental results for several different mixing vane options are reported for operation of a 12.5 cm engineering-scale contactor unit. Fewer straight vanes give greater mixing-zone hold-up compared to curved vanes. Quantitative comparison of droplet size distribution also showed a significant decrease in mean diameter for four straight vanes versus eight curved vanes. This set of measurements gives a compelling case for careful consideration of mixing vane geometry when evaluating hydraulic operation and extraction process efficiency of annular centrifugalmore » contactors.« less

Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico.

PubMed

Goldstein, Steven J; Abdel-Fattah, Amr I; Murrell, Michael T; Dobson, Patrick F; Norman, Deborah E; Amato, Ronald S; Nunn, Andrew J

2010-03-01

Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ( approximately 10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that (230)Th/(238)U activity ratios range from 0.005 to 0.48 and (226)Ra/(238)U activity ratios range from 0.006 to 113. (239)Pu/(238)U mass ratios for the saturated zone are <2 x 10(-14), and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order (238)U approximately (226)Ra > (230)Th approximately (239)Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

Modeling hyporheic zone processes

USGS Publications Warehouse

Runkel, Robert L.; McKnight, Diane M.; Rajaram, Harihar

2003-01-01

Stream biogeochemistry is influenced by the physical and chemical processes that occur in the surrounding watershed. These processes include the mass loading of solutes from terrestrial and atmospheric sources, the physical transport of solutes within the watershed, and the transformation of solutes due to biogeochemical reactions. Research over the last two decades has identified the hyporheic zone as an important part of the stream system in which these processes occur. The hyporheic zone may be loosely defined as the porous areas of the stream bed and stream bank in which stream water mixes with shallow groundwater. Exchange of water and solutes between the stream proper and the hyporheic zone has many biogeochemical implications, due to differences in the chemical composition of surface and groundwater. For example, surface waters are typically oxidized environments with relatively high dissolved oxygen concentrations. In contrast, reducing conditions are often present in groundwater systems leading to low dissolved oxygen concentrations. Further, microbial oxidation of organic materials in groundwater leads to supersaturated concentrations of dissolved carbon dioxide relative to the atmosphere. Differences in surface and groundwater pH and temperature are also common. The hyporheic zone is therefore a mixing zone in which there are gradients in the concentrations of dissolved gasses, the concentrations of oxidized and reduced species, pH, and temperature. These gradients lead to biogeochemical reactions that ultimately affect stream water quality. Due to the complexity of these natural systems, modeling techniques are frequently employed to quantify process dynamics.

Design of a new static micromixer having simple structure and excellent mixing performance.

PubMed

Kamio, Eiji; Ono, Tsutomu; Yoshizawa, Hidekazu

2009-06-21

A novel micromixer with simple construction and excellent mixing performance is developed. The micromixer is composed of two stainless steel tubes with different diameters: one is an outer tube and another is an inner tube which fits in the outer tube. In this micromixer, one reactant fluid flows in the mixing zone from the inner tube and the other flows from the outer tube. The excellent mixing performance is confirmed by comparing the results of a Villermaux/Dushman reaction with those for the other micromixers. The developed micromixer has a mixing cascade with multiple means and an asymmetric structure to achieve effective mixing. The excellent mixing performance of the developed micromixer suggests that serial addition of multiple phenomena for mixing will give us an efficient micromixing.

Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray Characteristics

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

2014-01-01

Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 deg is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.

Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray Characteristics

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

2015-01-01

Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 degrees is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.

Iodine I 131 Tositumomab, Etoposide and Cyclophosphamide Followed by Autologous Stem Cell Transplant in Treating Patients With Relapsed or Refractory Non-Hodgkin's Lymphoma

ClinicalTrials.gov

2017-07-21

Anaplastic Large Cell Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Splenic Marginal Zone Lymphoma; Waldenström Macroglobulinemia

Borehole geophysical, fluid, and hydraulic properties within and surrounding the freshwater/saline-water transition zone, San Antonio segment of the Edwards aquifer, south-central Texas, 2010-11

USGS Publications Warehouse

Thomas, Jonathan V.; Stanton, Gregory P.; Lambert, Rebecca B.

2012-01-01

Although analyses of daily mean equivalent freshwater heads for the East Uvalde transect indicated that the gradient across the freshwater/saline-water interface varied between into and out of the freshwater zone, the data indicate that there was a slightly longer period during which the gradient was out of the freshwater zone. Analyses of all daily mean equivalent freshwater heads for the Tri-County transect indicated that the lateral-head gradients across the freshwater/saline-water interface were typically mixed (not indicative of flow into or out of freshwater zone). Assessment of the daily mean equivalent freshwater heads indicated that, although the lateral-head gradient at the Kyle transect varied between into and out of the freshwater zone, the lateral-head gradient was typically from the transition zone into the freshwater zone.

Novelty and its ecological implications to dry forest functioning and conservation

Treesearch

Ariel Lugo; Heather Erickson

2017-01-01

Tropical and subtropical dry forest life zones support forests with lower stature and species richness than do tropical and subtropical life zones with greater water availability. The number of naturalized species that can thrive and mix with native species to form novel forests in dry forest conditions in Puerto Rico and the US Virgin Islands is lower than in other...

Prevention of deleterious deposits in a coal liquefaction system

DOEpatents

Carr, Norman L.; Prudich, Michael E.; King, Jr., William E.; Moon, William G.

1984-07-03

A process for preventing the formation of deleterious coke deposits on the walls of coal liquefaction reactor vessels involves passing hydrogen and a feed slurry comprising feed coal and recycle liquid solvent to a coal liquefaction reaction zone while imparting a critical mixing energy of at least 3500 ergs per cubic centimeter of reaction zone volume per second to the reacting slurry.

Widespread introgression in deep-sea hydrothermal vent mussels.

PubMed

Breusing, Corinna; Vrijenhoek, Robert C; Reusch, Thorsten B H

2017-01-13

The analysis of hybrid zones is crucial for gaining a mechanistic understanding of the process of speciation and the maintenance of species boundaries. Hybrid zones have been studied intensively in terrestrial and shallow-water ecosystems, but very little is known about their occurrence in deep-sea environments. Here we used diagnostic, single nucleotide polymorphisms in combination with one mitochondrial gene to re-examine prior hypotheses about a contact zone involving deep-sea hydrothermal vent mussels, Bathymodiolus azoricus and B. puteoserpentis, living along the Mid-Atlantic Ridge. Admixture was found to be asymmetric with respect to the parental species, while introgression was more widespread geographically than previously recognized. Admixed individuals with a majority of alleles from one of the parental species were most frequent in habitats corresponding to that species. Mussels found at a geographically intermediate vent field constituted a genetically mixed population that showed no evidence for hybrid incompatibilities, a finding that does not support a previously inferred tension zone model. Our analyses indicate that B. azoricus and B. puteoserpentis hybridize introgressively across a large geographic area without evidence for general hybrid incompatibilities. While these findings shed new light onto the genetic structure of this hybrid zone, many aspects about its nature still remain obscure. Our study sets a baseline for further research that should primarily focus on the acquisition of additional mussel samples and environmental data, a detailed exploration of vent areas and hidden populations as well as genomic analyses in both mussel hosts and their bacterial symbionts.

Ground cover, erosion risk and production implications of targeted management practices in Australian mixed farming systems: lessons from the Grain and Graze program

USDA-ARS?s Scientific Manuscript database

Maintaining the productive capacity of the agricultural soils of Australia's broadacre cropping zone requires careful management, given a highly variable climate and soils that are susceptible to degradation. Mixed croplivestock farming systems are the predominant land use across these regions and m...

Downhole material injector for lost circulation control

DOEpatents

Glowka, D.A.

1991-01-01

This invention is comprised of an apparatus and method for simultaneously and separately emplacing two streams of different materials through a drillstring in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drillstring at the desired downhole location and harden only after mixing for control of a lost circulation zone.

Downhole material injector for lost circulation control

DOEpatents

Glowka, D.A.

1994-09-06

Apparatus and method are disclosed for simultaneously and separately emplacing two streams of different materials through a drill string in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drill string at the desired downhole location and harden only after mixing for control of a lost circulation zone. 6 figs.

Hygrothermal Anaylsis of Wood-Frame Wall Assemblies in a Mixed-Humid Climate

Treesearch

Samuel V. Glass

2013-01-01

This study uses a one-dimensional hygrothermal model to investigate the moisture performance of 10 residential wood-frame wall assemblies in a representative mixed-humid climate location of Baltimore, Maryland (climate zone 4A). All the assemblies include oriented strandboard (OSB) sheathing and vinyl siding. The walls differ in stud cavity thickness, level of cavity...

Alongshore momentum transfer to the nearshore zone from energetic ocean waves generated by passing hurricanes

NASA Astrophysics Data System (ADS)

Mulligan, Ryan P.; Hanson, Jeffrey L.

2016-06-01

Wave and current measurements from a cross-shore array of nearshore sensors in Duck, NC, are used to elucidate the balance of alongshore momentum under energetic wave conditions with wide surf zones, generated by passing hurricanes that are close to and far from to the coast. The observations indicate that a distant storm (Hurricane Bill, 2009) with large waves has low variability in directional wave characteristics resulting in alongshore currents that are driven mainly by the changes in wave energy. A storm close to the coast (Hurricane Earl, 2010), with strong local wind stress and combined sea and swell components in wave energy spectra, has high variability in wave direction and wave period that influence wave breaking and nearshore circulation as the storm passes. During both large wave events, the horizontal current shear is strong and radiation stress gradients, bottom stress, wind stress, horizontal mixing, and cross-shore advection contribute to alongshore momentum at different spatial locations across the nearshore region. Horizontal mixing during Hurricane Earl, estimated from rotational velocities, was particularly strong suggesting that intense eddies were generated by the high horizontal shear from opposing wind-driven and wave-driven currents. The results provide insight into the cross-shore distribution of the alongshore current and the connection between flows inside and outside the surf zone during major storms, indicating that the current shear and mixing at the interface between the surf zone and shallow inner shelf is strongly dependent on the distance from the storm center to the coast.

Scalar mixing in LES/PDF of a high-Ka premixed turbulent jet flame

NASA Astrophysics Data System (ADS)

You, Jiaping; Yang, Yue

2016-11-01

We report a large-eddy simulation (LES)/probability density function (PDF) study of a high-Ka premixed turbulent flame in the Lund University Piloted Jet (LUPJ) flame series, which has been investigated using direct numerical simulation (DNS) and experiments. The target flame, featuring broadened preheat and reaction zones, is categorized into the broken reaction zone regime. In the present study, three widely used mixing modes, namely the Interaction by Exchange with the Mean (IEM), Modified Curl (MC), and Euclidean Minimum Spanning Tree (EMST) models are applied to assess their performance through detailed a posteriori comparisons with DNS. A dynamic model for the time scale of scalar mixing is formulated to describe the turbulent mixing of scalars at small scales. Better quantitative agreement for the mean temperature and mean mass fractions of major and minor species are obtained with the MC and EMST models than with the IEM model. The multi-scalar mixing in composition space with the three models are analyzed to assess the modeling of the conditional molecular diffusion term. In addition, we demonstrate that the product of OH and CH2O concentrations can be a good surrogate of the local heat release rate in this flame. This work is supported by the National Natural Science Foundation of China (Grant Nos. 11521091 and 91541204).

Coastal mining

NASA Astrophysics Data System (ADS)

Bell, Peter M.

The Exclusive Economic Zone (EEZ) declared by President Reagan in March 1983 has met with a mixed response from those who would benefit from a guaranteed, 200-nautical-mile (370-km) protected underwater mining zone off the coasts of the United States and its possessions. On the one hand, the U.S. Department of the Interior is looking ahead and has been very successful in safeguarding important natural resources that will be needed in the coming decades. On the other hand, the mining industry is faced with a depressed metals and mining market.A report of the Exclusive Economic Zone Symposium held in November 1983 by the U.S. Geological Survey, the Mineral Management Service, and the Bureau of Mines described the mixed response as: “ … The Department of Interior … raring to go into promotion of deep-seal mining but industrial consortia being very pessimistic about the program, at least for the next 30 or so years.” (Chemical & Engineering News, February 5, 1983).

Development of the technique of terahertz pulse spectroscopy for diagnostic malignant tumors during gastrointestinal surgeries

NASA Astrophysics Data System (ADS)

Goryachuk, A. A.; Khodzitsky, M. K.; Borovkova, M. A.; Khamid, A. K.; Dutkinskii, P. S.; Shishlo, D. A.

2016-08-01

Samples of fresh excised tissues obtained from patients who had undergone gastric cancer have been investigated. Samples were consisted of cancer zone, normal zone and zone mixed of normal and cancer tissues. Their optical properties and spectral features were investigated by terahertz time-domain spectroscopy (TDS) in reflection mode. It was found that waveforms of reflected signals from normal and cancer tissues were well distinguished so it can be concluded that it is easy to discriminate gastric cancer tissue from normal by using THz TDS.

Radon and radium in the ice-covered Arctic Ocean, and what they reveal about gas exchange in the sea ice zone.

NASA Astrophysics Data System (ADS)

Loose, B.; Kelly, R. P.; Bigdeli, A.; Moran, S. B.

2014-12-01

The polar sea ice zones are regions of high primary productivity and interior water mass formation. Consequently, the seasonal sea ice cycle appears important to both the solubility and biological carbon pumps. To estimate net CO2 transfer in the sea ice zone, we require accurate estimates of the air-sea gas transfer velocity. In the open ocean, the gas transfer velocity is driven by wind, waves and bubbles - all of which are strongly altered by the presence of sea ice, making it difficult to translate open ocean estimates of gas transfer to the ice zone. In this study, we present profiles of 222Rn and 226Ra throughout the mixed-layer and euphotic zone. Profiles were collected spanning a range of sea ice cover conditions from 40 to 100%. The profiles of Rn/Ra can be used to estimate the gas transfer velocity, but the 3.8 day half-life of 222Rn implies that mixed layer radon will have a memory of the past ~20 days of gas exchange forcing, which may include a range of sea ice cover conditions. Here, we compare individual estimates of the gas transfer velocity to the turbulent forcing conditions constrained from shipboard and regional reanalysis data to more appropriately capture the time history upper ocean Rn/Ra.

Estimation of bias with the single-zone assumption in measurement of residential air exchange using the perfluorocarbon tracer gas method

PubMed Central

Van Ryswyk, K; Wallace, L; Fugler, D; MacNeill, M; Héroux, M È; Gibson, M D; Guernsey, J R; Kindzierski, W; Wheeler, A J

2015-01-01

Residential air exchange rates (AERs) are vital in understanding the temporal and spatial drivers of indoor air quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed air zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER1z). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER2z). In total, 287 daily pairs of AER2z and AER1z estimates were made from 35 homes across three cities. In 87% of the cases, AER2z was higher than AER1z. Overall, the AER1z estimates underestimated AER2z by approximately 16% (IQR: 5–32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential air exchange using a single PFT gas, the assumption of a single well-mixed air zone very likely results in an under prediction of the AER. PMID:25399878

Computational models for the viscous/inviscid analysis of jet aircraft exhaust plumes

NASA Astrophysics Data System (ADS)

Dash, S. M.; Pergament, H. S.; Thorpe, R. D.

1980-05-01

Computational models which analyze viscous/inviscid flow processes in jet aircraft exhaust plumes are discussed. These models are component parts of an NASA-LaRC method for the prediction of nozzle afterbody drag. Inviscid/shock processes are analyzed by the SCIPAC code which is a compact version of a generalized shock capturing, inviscid plume code (SCIPPY). The SCIPAC code analyzes underexpanded jet exhaust gas mixtures with a self-contained thermodynamic package for hydrocarbon exhaust products and air. A detailed and automated treatment of the embedded subsonic zones behind Mach discs is provided in this analysis. Mixing processes along the plume interface are analyzed by two upgraded versions of an overlaid, turbulent mixing code (BOAT) developed previously for calculating nearfield jet entrainment. The BOATAC program is a frozen chemistry version of BOAT containing the aircraft thermodynamic package as SCIPAC; BOATAB is an afterburning version with a self-contained aircraft (hydrocarbon/air) finite-rate chemistry package. The coupling of viscous and inviscid flow processes is achieved by an overlaid procedure with interactive effects accounted for by a displacement thickness type correction to the inviscid plume interface.

Computational models for the viscous/inviscid analysis of jet aircraft exhaust plumes. [predicting afterbody drag

NASA Technical Reports Server (NTRS)

Dash, S. M.; Pergament, H. S.; Thorpe, R. D.

1980-01-01

Computational models which analyze viscous/inviscid flow processes in jet aircraft exhaust plumes are discussed. These models are component parts of an NASA-LaRC method for the prediction of nozzle afterbody drag. Inviscid/shock processes are analyzed by the SCIPAC code which is a compact version of a generalized shock capturing, inviscid plume code (SCIPPY). The SCIPAC code analyzes underexpanded jet exhaust gas mixtures with a self-contained thermodynamic package for hydrocarbon exhaust products and air. A detailed and automated treatment of the embedded subsonic zones behind Mach discs is provided in this analysis. Mixing processes along the plume interface are analyzed by two upgraded versions of an overlaid, turbulent mixing code (BOAT) developed previously for calculating nearfield jet entrainment. The BOATAC program is a frozen chemistry version of BOAT containing the aircraft thermodynamic package as SCIPAC; BOATAB is an afterburning version with a self-contained aircraft (hydrocarbon/air) finite-rate chemistry package. The coupling of viscous and inviscid flow processes is achieved by an overlaid procedure with interactive effects accounted for by a displacement thickness type correction to the inviscid plume interface.

Chemical and Hydrologic Data From the Cement Creek and Upper Animas River Confluence and Mixing Zone, Silverton, Colorado, September 1997

USGS Publications Warehouse

Schemel, Laurence E.; Cox, Marisa H.

2007-01-01

Cement Creek, an acidic tributary, discharges into the circum-neutral Animas River (pH>7) in Silverton, Colorado located in the high-elevation San Juan Mountains. Mixing of Animas River water with acidic metal rich Cement Creek water raises water pH and produces metal precipitates. This report presents selected anion, cation, chloride, and sulfate data along with hydrologic data highlighting the mixing of these streams during the low-flow period in late summer 1997.

Centrifugal pyrocontactor

DOEpatents

Chow, Lorac S.; Leonard, Ralph A.

1993-01-01

A method for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor.

Centrifugal pyrocontactor

DOEpatents

Chow, L.S.; Leonard, R.A.

1993-10-19

A method is described for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor. 6 figures.

Structural architecture and petrophysical properties of the Rocca di Neto extensional fault zone developed in the shallow marine sediments of the Crotone Basin (Southern Apennines, Italy).

NASA Astrophysics Data System (ADS)

Pizzati, Mattia; Balsamo, Fabrizio; Iacumin, Paola; Swennen, Rudy; Storti, Fabrizio

2017-04-01

In this contribution we describe the architecture and petrophysical properties of the Rocca di Neto extensional fault zone in loose and poorly lithified sediments, located in the Crotone forearc basin (south Italy). To this end, we combined fieldwork with microstructural observations, grain size analysis, and in situ permeability measurements. The studied fault zone has an estimated maximum displacement of 80-90 m and separates early Pleistocene age (Gelasian) sands in the footwall from middle Pleistocene (Calabrian) silty clay in the hangingwall. The analysed outcrop consists of about 70 m section through the fault zone mostly developed in the footwall block. Fault zone consists of four different structural domains characterized by distinctive features: (1) <1 m-thick fault core (where the majority of the displacement is accommodated) in which bedding is transposed into foliation imparted by grain preferential orientation and some black gouges decorate the main slip surfaces; (2) zone of tectonic mixing characterized by a set of closely spaced and anastomosed deformation bands parallel to the main slip surface; (3) about 8 m-thick footwall damage zone characterized by synthetic and antithetic sets of deformation bands; (4) zone of background deformation with a few, widely-spaced conjugate minor faults and deformation bands. The boundary between the relatively undeformed sediments and the damage zone is not sharp and it is characterized by a progressive decrease in deformation intensity. The silty clay in the hangingwall damage zone is characterized by minor faults. Grain size and microstructural data indicate that particulate flow with little amount of cataclasis is the dominant deformation mechanism in both fault core rocks and deformation bands. Permeability of undeformed sediments is about 70000 mD, whereas the permeability in deformation bands ranges from 1000 to 18000 mD; within the fault core rocks permeability is reduced up to 3-4 orders of magnitude respect to the undeformed domains. Structural and petrophysical data suggest that the Rocca di Neto fault zone may compartmentalize the footwall block due to both juxtaposition of clay-rich lithology in the hangingwall and the development of low permeability fault core rocks.

Relating rheology to geometry in large-scale natural shear zones

NASA Astrophysics Data System (ADS)

Platt, John

2016-04-01

The geometry and width of the ductile roots of plate boundary scale faults are very poorly understood. Some field and geophysical data suggests widths of tens of km in the lower crust, possibly more in the upper mantle. Other observations suggest they are much narrower. Dip slip shear zones may flatten out and merge into zones of subhorizontal lower crustal or asthenospheric flow. The width of a ductile shear zone is simply related to relative velocity and strain rate. Strain rate is related to stress through the constitutive relationship. Can we constrain the stress, and do we understand the rheology of materials in ductile shear zones? A lot depends on how shear zones are initiated. If they are localized by pre-existing structures, width and/or rheology may be inherited, and we have too many variables. If shear zones are localized primarily by shear heating, initial shear stress has to be very high (> 1 GPa) to overcome conductive heat loss, and very large feedbacks (both positive and negative) make the system highly unstable. Microstructural weakening requires a minimum level of stress to cause deformation and damage in surrounding rock, thereby buffering the stress. Microstructural weakening leads to grain-size sensitive creep, for which we have constitutive laws, but these are complicated by phase mixing in polyphase materials, by viscous anisotropy, by hydration, and by changes in mineral assemblage. Here are some questions that need to be addressed. (1) If grain-size reduction by dynamic recrystallization results in a switch to grain-size sensitive creep (GSSC) in a stress-buffered shear zone, does dynamic recrystallization stop? Does grain growth set in? If grain-size is still controlled by dislocation processes, then the effective stress exponent for GSSC is 4-5, even though the dominant mechanism may be diffusion and/or grain-boundary sliding (GBS). (2) Is phase mixing in ultramylonites primarily a result of GBS + neighbour switching, creep cavitation and diffusion, or metamorphic reactions? (3) In two-phase / polyphase mixtures, does the strong phase generally form a load-bearing framework, favoring constant strain-rate (Voigt) bound behavior, or does the weak phase form through-going strain pathways, favoring constant stress (Reuss) bound behavior, or do the phases remain well mixed, favoring an intermediate behavior (e.g., Tullis et al model)? (4) How do we deal with the rheological effect of water? Is it simply an unconstrained variable in nature? Is the water fugacity model in flow laws adequate? (5) How can we better relate experimental results (often carried out at constant strain-rate, and not reaching microstructural steady state) to deformation in natural shear zones? Rheological observations on well-constrained natural shear zones are helping us answer some of these questions.

Chemistry, isotopic composition, and origin of a methane-hydrogen sulfide hydrate at the Cascadia subduction zone

USGS Publications Warehouse

Kastner, M.; Kvenvolden, K.A.; Lorenson, T.D.

1998-01-01

Although the presence of extensive gas hydrate on the Cascadia margin, offshore from the western U.S. and Canada, has been inferred from marine seismic records and pore water chemistry, solid gas hydrate has only been found at one location. At Ocean Drilling Program (ODP) Site 892, offshore from central Oregon, gas hydrate was recovered close to the sediment - water interface at 2-19 m below the seafloor, (mbsf) at 670 m water depth. The gas hydrate occurs as elongated platy crystals or crystal aggregates, mostly disseminated irregularly, with higher concentrations occurring in discrete zones, thin layers, and/or veinlets parallel or oblique to the bedding. A 2-to 3-cm thick massive gas hydrate layer, parallel to bedding, was recovered at ???17 mbsf. Gas from a sample of this layer was composed of both CH4 and H2S. This sample is the first mixed-gas hydrate of CH4-H2S documented in ODP; it also contains ethane and minor amounts of CO2. Measured temperature of the recovered core ranged from 2 to - 18??C and are 6 to 8 degrees lower than in-situ temperatures. These temperature anomalies were caused by the partial dissociation of the CH4-H2S hydrate during recovery without a pressure core sampler. During this dissociation, toxic levels of H2S (??34S, +27.4???) were released. The ??13C values of the CH4 in the gas hydrate, -64.5 to -67.5???(PDB), together with ??D values of - 197 to - 199???(SMOW) indicate a primarily microbial source for the CH4. The ??18O value of the hydrate H2O is +2.9???(SMOW), comparable with the experimental fractionation factor for sea-ice. The unusual composition (CH4-H2S) and depth distribution (2-19 mbsf) of this gas hydrate indicate mixing between a methane-rich fluid with a pore fluid enriched in sulfide; at this site the former is advecting along an inclined fault into the active sulfate reduction zone. The facts that the CH4-H2S hydrate is primarily confined to the present day active sulfate reduction zone (2-19 mbsf), and that from here down to the BSR depth (19-68 mbsf) the gas hydrate inferred to exist is a ???99% CH4 hydrate, suggest that the mixing of CH4 and H2S is a geologically young process. Because the existence of a mixed CH4-H2S hydrate is indicative of moderate to intense advection of a methane-rich fluid into a near surface active sulfate reduction zone, technically active (faulted) margins with organic-rich sediments and moderate to high sedimentation rates are the most likely regions of occurrence. The extension of such a mixed hydrate below the sulfate reduction zone should reflect the time-span of methane advection into the sulfate reduction zone. ?? 1998 Elsevier Science B.V. All rights reserved.

Turbidity as a control on phytoplankton biomass and productivity in estuaries

USGS Publications Warehouse

Cloern, J.E.

1987-01-01

In many coastal plain estuaries light attenuation by suspended sediments confines the photic zone to a small fraction of the water column, such that light limitation is a major control on phytoplankon production and turnover rate. For a variety of estuarine systems (e.g. San Francisco Bay, Puget Sound, Delaware Bay, Hudson River plume), photic-zone productivity can be estimated as a function of phytoplankton biomass times mean irradiance of the photic zone. Net water column productivity also varies with light availability, and in San Francisco Bay net productivity is zero (estimated respiratory loss of phytoplankton balances photosynthesis) when the ratio of photic depth (Zp) to mixed depth (Zm) is less than about 0.2. Thus whenever Zp:Zm < 0.2, the water column is a sink for phytoplankton production. Much of the spatial and temporal variability of phytoplankton biomass or productivity in estuaries is explained by variations in the ratio of photic depth to mixed depth. For example, phytoplankton blooms often coincide with stratification events that reduce the depth of the surface mixed layer (increase Zp:Zm). Shallow estuarine embayments (high Zp:Zm) are often characterized by high phytoplankton biomass relative to adjacent channels (low Zp:Zm). Many estuaries have longitudinal gradients in productivity that mirror the distribution of suspended sediments: productivity is low near the riverine source of sediments (low Zp:Zm) and increases toward the estuary mouth where turbidity decreases. Some of these generalizations are qualitative in nature, and detailed understanding of the interaction between turbidity and estuarine phytoplankton dynamics requires improved understanding of vertical mixing rates and phytoplankton respiration. ?? 1987.

Speed of sound measurements and mixing characterization of underexpanded fuel jets with supercritical reservoir condition using laser-induced thermal acoustics

NASA Astrophysics Data System (ADS)

Baab, S.; Förster, F. J.; Lamanna, G.; Weigand, B.

2016-11-01

The four-wave mixing technique laser-induced thermal acoustics was used to measure the local speed of sound in the farfield zone of extremely underexpanded jets. N-hexane at supercritical injection temperature and pressure (supercritical reservoir condition) was injected into quiescent subcritical nitrogen (with respect to the injectant). The technique's capability to quantify the nonisothermal, turbulent mixing zone of small-scale jets is demonstrated for the first time. Consistent radially resolved speed of sound profiles are presented for different axial positions and varying injection temperatures. Furthermore, an adiabatic mixing model based on nonideal thermodynamic properties is presented to extract mixture composition and temperature from the experimental speed of sound data. High fuel mass fractions of up to 94 % are found for the centerline at an axial distance of 55 diameters from the nozzle followed by a rapid decay in axial direction. This is attributed to a supercritical fuel state at the nozzle exit resulting in the injection of a high-density fluid. The obtained concentration data are complemented by existing measurements and collapsed in a similarity law. It allows for mixture prediction of underexpanded jets with supercritical reservoir condition provided that nonideal thermodynamic behavior is considered for the nozzle flow. Specifically, it is shown that the fuel concentration in the farfield zone is very sensitive to the thermodynamic state at the nozzle exit. Here, a transition from supercritical fluid to subcritical vapor state results in strongly varying fuel concentrations, which implies high impact on the mixture formation and, consequently, on the combustion characteristics.

Fault fluid evolution at the outermost edges of the southern Apennines fold-and-thrust belt, Italy

NASA Astrophysics Data System (ADS)

Agosta, Fabrizio; Belviso, Claudia; Cavalcante, Francesco; Vita Petrullo, Angela

2017-04-01

This work focuses on the structural architecture and mineralization of a high-angle, extensional fault zone that crosscuts the Middle Pleistocene tuffs and pyroclastites of the Vulture Volcano, southern Italy. This fault zone is topped by a few m-thick travertine deposit formed by precipitation, in a typical lacustrine depositional environment, from a fault fluid that included a mixed, biogenic- and mantle-derived CO2. The detailed analysis of its different mineralization can shed new lights into the shallow crustal fluid flow that took place during deformation of the outer edge of the southern Apennines fold-and-thrust belt. In fact, the study fault zone is interpreted as a shallow-seated, tear fault associated with a shallow thrust fault displacing the most inner portion of the Bradano foredeep basin infill, and was thus active during the latest stages of contractional deformation. Far from the fault zone, the fracture network is made up of three high-angle joint sets striking N-S, E-W and NW-SE, respectively. The former two sets can be interpreted as the older structural elements that pre-dated the latter one, which is likely due to the current stress state that affects the whole Italian peninsula. In the vicinity of the fault zone, a fourth joint high-angle set striking NE-SW is also present, which becomes the most dominant fracture set within the study footwall fault damage zone. Detailed X-ray diffraction analysis of the powder obtained from hand specimens representative of the multiple mineralization present within the fault zone, and in the surrounding volcanites, are consistent with circulation of a fault fluid that modified its composition with time during the latest stages of volcanic activity and contractional deformation. Specifically, veins infilled with and slickenside coated by jarosite, Opal A and/or goethite are found in the footwall fault damage zone. Based upon the relative timing of formation of the aforementioned joint sets, deciphered after an accurate analysis of their abutting and crosscutting relationships, we envision that the fault fluid was first likely derived from a deep-seated, acid fluid, which interacted with either Triassic or Messinian in age evaporitic rocks during its ascendance from depth. From such a fluid, jarosite precipitated within N-S and NE-SW joints and sheared joints located both away and within the fault damage zone. Then, very warm fluids similar to the lahars that were channeled along the eastern flank of the Vulture Volcano caused the precipitation of Opal A within the dense fracture network of the footwall damage zone, likely causing its hydraulic fracturing, and in the N-S striking veins present in the vicinity of the fault zone. Finally, gotheite coated the major slickensides and sealed the NE-SW fractures, postdating all previous mineralization. Gothetite precipitate from a fault fluid, meteoric in origin, which interacted with the volcanic aquifer causing oxidation of the iron-rich minerals.

The chemically zoned 1949 eruption on La Palma (Canary Islands): Petrologic evolution and magma supply dynamics of a rift zone eruption

NASA Astrophysics Data System (ADS)

Klügel, Andreas; Hoernle, Kaj A.; Schmincke, Hans-Ulrich; White, James D. L.

2000-03-01

The 1949 rift zone eruption along the Cumbre Vieja ridge on La Palma involved three eruptive centers, 3 km spaced apart, and was chemically and mineralogically zoned. Duraznero crater erupted tephrite for 14 days and shut down upon the opening of Llano del Banco, a fissure that issued first tephrite and, after 3 days, basanite. Hoyo Negro crater opened 4 days later and erupted basanite, tephrite, and phonotephrite, while Llano del Banco continued to issue basanite. The eruption ended with Duraznero erupting basanite with abundant crustal and mantle xenoliths. The tephrites and basanites from Duraznero and Llano del Banco show narrow compositional ranges and define a bimodal suite. Each batch ascended and evolved separately without significant intermixing, as did the Hoyo Negro basanite, which formed at lower degrees of melting. The magmas fractionated clinopyroxene +olivine±kaersutite±Ti-magnetite at 600-800 MPa and possibly 800-1100 MPa. Abundant reversely zoned phenocrysts reflect mixing with evolved melts at mantle depths. Probably as early as 1936, Hoyo Negro basanite entered the deep rift system at 200-350 MPa. Some shallower pockets of this basanite evolved to phonotephrite through differentiation and assimilation of wall rock. A few months prior to eruption, a mixing event in the mantle may have triggered the final ascent of the magmas. Most of the erupted tephrite and basanite ascended from mantle depths within hours to days without prolonged storage in crustal reservoirs. The Cumbre Vieja rift zone differs from the rift zones of Kilauea volcano (Hawaii) in lacking a summit caldera or a summit reservoir feeding the rift system and in being smaller and less active with most of the rift magma solidifying between eruptions.

Development of k-300 concrete mix for earthquake-resistant Housing infrastructure in indonesia

NASA Astrophysics Data System (ADS)

Zulkarnain, Fahrizal

2018-03-01

In determining the strength of K-300 concrete mix that is suitable for earthquake-resistant housing infrastructure, it is necessary to research the materials to be used for proper quality and quantity so that the mixture can be directly applied to the resident’s housing, in the quake zone. In the first stage, the examination/sieve analysis of the fine aggregate or sand, and the sieve analysis of the coarse aggregate or gravel will be carried out on the provided sample weighing approximately 40 kilograms. Furthermore, the specific gravity and absorbance of aggregates, the examination of the sludge content of aggregates passing the sieve no. 200, and finally, examination of the weight of the aggregate content. In the second stage, the planned concrete mix by means of the Mix Design K-300 is suitable for use in Indonesia, with implementation steps: Planning of the cement water factor (CWF), Planning of concrete free water (Liters / m3), Planning of cement quantity, Planning of minimum cement content, Planning of adjusted cement water factor, Planning of estimated aggregate composition, Planning of estimated weight of concrete content, Calculation of composition of concrete mixture, Calculation of mixed correction for various water content. Implementation of the above tests also estimates the correction of moisture content and the need for materials of mixture in kilograms for the K-300 mixture, so that the slump inspection result will be achieved in planned 8-12 cm. In the final stage, a compressive strength test of the K-300 experimental mixture is carried out, and subsequently the composition of the K-300 concrete mixture suitable for one sack of cement of 50 kg is obtained for the foundation of the proper dwelling. The composition is consists of use of Cement, Sand, Gravel, and Water.

Shipboard measurements and modeling of the distribution of CH4 and 13CH4 in the western Pacific

NASA Astrophysics Data System (ADS)

Bromley, T.; Allan, W.; Martin, R.; Mikaloff Fletcher, S. E.; Lowe, D. C.; Struthers, H.; Moss, R.

2012-02-01

We present observations of methane (CH4) mixing ratio and 13C/12C isotopic ratios in CH4 (δ13C) data from a collaborative shipboard project using bulk carrier ships sailing between Nelson, New Zealand, and Osaka, Japan, in the western Pacific Ocean. Measurements of the CH4 mixing ratio and δ13C in CH4were obtained from large clean-air samples collected in each 2.5° to 5° of latitude between 30°S and 30°N on eight voyages from 2004 to 2007. The data show large variations in CH4 mixing ratio in the tropical western Pacific, and data analysis suggests that these large variations are related to the positions and strengths of the South Pacific Convergence Zone and the Intertropical Convergence Zone, with variability in the sources playing a much smaller role. These measurements are compared with results from a modified version of the Unified Model (UMeth) general circulation model along two transects, one similar to the ship transects and another 18.75° to the east. Although UMeth was run to a steady state with the same sources and sinks each year, the gradient structures varied considerably from year to year, supporting our conclusion that variability in transport is a major driver for the observed variations in CH4. Simulations forced with an idealized representation of the El Niño-Southern Oscillation (ENSO) suggest that a large component of the observed variability in latitudinal gradients of CH4 and its δ13C arises from intrinsic variability in the climate system that does not occur on ENSO time scales.

Ground-water flow simulation and chemical and isotopic mixing equation analysis to determine source contributions to the Missouri River alluvial aquifer in the vicinity of the Independence, Missouri, well field

USGS Publications Warehouse

Kelly, Brian P.

2002-01-01

The city of Independence, Missouri, operates a well field in the Missouri River alluvial aquifer. Steady-state ground-water flow simulation, particle tracking, and the use of chemical and isotopic composition of river water, ground water, and well-field pumpage in a two-component mixing equation were used to determine the source contributions of induced inflow from the Missouri River and recharge to ground water from precipitation in well-field pumpage. Steady-state flow-budget analysis for the simulation-defined zone of contribution to the Independence well field indicates that 86.7 percent of well-field pumpage is from induced inflow from the river, and 6.7 percent is from ground-water recharge from precipitation. The 6.6 percent of flow from outside the simulation-defined zone of contribution is a measure of the uncertainty of the estimation, and occurs because model cells are too large to uniquely define the actual zone of contribution. Flow-budget calculations indicate that the largest source of water to most wells is the Missouri River. Particle-tracking techniques indicate that the Missouri River supplies 82.3 percent of the water to the Independence well field, ground-water recharge from precipitation supplies 9.7 percent, and flow from outside defined zones of contribution supplies 8.0 percent. Particle tracking was used to determine the relative amounts of source water to total well-field pumpage as a function of traveltime from the source. Well-field pumpage that traveled 1 year or less from the source was 8.8 percent, with 0.6 percent from the Missouri River, none from precipitation, and 8.2 percent between starting cells. Well-field pumpage that traveled 2 years or less from the source was 10.3 percent, with 1.8 percent from the Missouri River, 0.2 percent from precipitation, and 8.3 percent between starting cells. Well-field pumpage that traveled 5 years or less from the source was 36.5 percent, with 27.1 percent from the Missouri River, 1.1 percent from precipitation, and 8.3 percent between starting cells. Well-field pumpage that traveled 10 years or less from the source was 42.7 percent, with 32.6 percent from the Missouri River, 1.8 percent from precipitation, and 8.3 percent between starting cells. Well-field pumpage that traveled 25 years or less from the source was 71.9 percent, with 58.9 percent from the Missouri River, 4.7 percent from precipitation, and 8.3 percent between starting cells. Results of chemical (calcium, sodium, iron, and fluoride) and isotopic (oxygen and hydrogen) analyses of water samples collected from the Missouri River, selected monitoring wells around the Independence well field, and combined well-field pumpage were used in a two component mixing equation to estimate the relative amount of Missouri River water in total well-field pumpage. The relative amounts of induced inflow from the Missouri River in well-field pumpage ranged from 49 percent for sodium to 80 percent for calcium, and sensitivities ranged from 0 percent for iron to plus or minus 35 percent for naturally occurring stable isotope (18O). The average of all mixing equation results indicated that 61 percent of well-field pumpage was from induced inflow from the Missouri River. All methods used in the study indicate that more than one-half of the water in well-field pumpage was inflow from the Missouri River. River inflow estimates from ground-water simulation methods are larger and error values are smaller than those using chemical and isotopic data in the mixing equation, although substantial uncertainties exist for both estimation methods. Because of the complex hydrology of the aquifer near the Independence well field, the source estimates using particle tracking probably are the most reliable of the ground-water simulation methods. Mixing equation results are less reliable than those of the ground-water simulation for this study. However, more reliable results can be obtained from the mixing equatio

Phonon anomalies in intermediate valent TmXSe and TmSe1 - yTey

NASA Astrophysics Data System (ADS)

Boppart, H.; Treindl, A.; Wachter, P.

1981-03-01

In TmxSe and TmSe1-yTey the degree of valence mixing can be adjusted between nearly 3+ for Tm0.87Se and 2.55+ for TmSe0.7Te0.3. The measurement of sound velocities vL, vTl and vT2 and the evaluation of the Raman effect for various compositions permit the derivation of LA [111] phonon dispersion at critical points in the Brillouin zone. vL decreases with increasing valence mixing. Near the middle of the zone the LA branch gets a dip for intermediate valent compositions, resulting in a characteristic peak in the Ramn spectrum at about 60 cm-1. The elastic constant c12 has been found negative for Tm0.99Se, also at 4.2 K. For uniaxial pressures c12 exhibits strong nonlinearities and even changes sign with pressure in an intermediate valent composition. The optical phonon frequencies, LO (L) also soften proportional with the degree of valence mixing.

Relationships Between Quantitative Pulse-Echo Ultrasound Parameters from the Superficial Zone of the Human Articular Cartilage and Changes in Surface Roughness, Collagen Content or Collagen Orientation Caused by Early Degeneration.

PubMed

Kiyan, Wataru; Ito, Akira; Nakagawa, Yasuaki; Mukai, Shogo; Mori, Koji; Arai, Tatsuo; Uchino, Eiichiro; Okuno, Yasushi; Kuroki, Hiroshi

2017-08-01

We aimed to quantitatively investigate the relationship between amplitude-based pulse-echo ultrasound parameters and early degeneration of the knee articular cartilage. Twenty samples from six human femoral condyles judged as grade 0 or 1 according to International Cartilage Repair Society grading were assessed using a 15-MHz pulsed-ultrasound 3-D scanning system ex vivo. Surface roughness (R q ), average collagen content (A 1 ) and collagen orientation (A 12 ) in the superficial zone of the cartilage were measured via laser microscopy and Fourier transform infrared imaging spectroscopy. Multiple regression analysis with a linear mixed-effects model (LMM) revealed that a time-domain reflection coefficient at the cartilage surface (R c ) had a significant coefficient of determination with R q and A 12 (R LMMm 2 =0.79); however, R c did not correlate with A 1 . Concerning the collagen characteristic in the superficial zone, R c was found to be a sensitive indicator reflecting collagen disorganization, not collagen content, for the early degeneration samples. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Effect of pin tool design on the material flow of dissimilar AA7075-AA6061 friction stir welds

NASA Astrophysics Data System (ADS)

Hasan, Mohammed M.; Ishak, M.; Rejab, M. R. M.

2017-10-01

Tool design is the most influential aspect in the friction stir welding (FSW) technology. Influence of pin tool geometry on material flow pattern are studied in this work during the FSW of dissimilar AA7075 and AA6061 aluminium alloys. Three truncated pin tool profiles (threaded, threaded with single flat, and unthreaded with single flat) were used to prepare the weldments. The workpieces were joined using a custom-made clamping system under 1100 rpm of spindle speed, 300 mm/min of traverse rate and 3° of tilt angle. The metallographic analysis showed that defect-free welds can be produced using the three pin tools with significant changes in the mixing stir zone structure. The results declared that the introducing of the flat on the cone of the probe deviates the pattern of the onion rings without changing the chemical composition of the created layers. This in turn improves the hardness distribution and tensile strength of the welded joint. It was also noted that both heat affected zone (HAZ) and thermal-mechanical affected zone (TMAZ) are similar in composition to their corresponding base materials (BM).

UPb ages of zircon rims: A new analytical method using the air-abrasion technique

USGS Publications Warehouse

Aleinikoff, J.N.; Winegarden, D.L.; Walter, M.

1990-01-01

We present a new technique for directly dating, by conventional techniques, the rims of zircons. Several circumstances, such as a xenocrystic or inherited component in igneous zircon and metamorphic overgrowths on igneous cores, can result in grains with physically distinct age components. Pneumatic abrasion has been previously shown by Krogh to remove overgrowths and damaged areas of zircon, leaving more resistant and isotopically less disturbed parts available for analysis. A new abrader design, which is capable of very gently grinding only tips and interfacial edges of even needle-like grains, permits easy collection of abraded material for dating. Five examples demonstrate the utility of the "dust-collecting" technique, including two studies that compare conventional, ion microprobe and abrader data. Common Pb may be strongly concentrated in the outermost zones of many zircons and this Pb is not easily removed by leaching (even in weak HF). Thus, the benefit of removing only the outermost zones (and avoiding mixing of age components) is somewhat compromised by the much higher common Pb contents which result in less precise age determinations. A very brief abrasion to remove the high common Pb zones prior to collection of material for dating is selected. ?? 1990.

Genetic Testing Plus Irinotecan in Treating Patients With Solid Tumors or Lymphoma

ClinicalTrials.gov

2013-01-23

AIDS-related Peripheral/Systemic Lymphoma; AIDS-related Primary CNS Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Adult T-cell Leukemia/Lymphoma; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Mycosis Fungoides/Sezary Syndrome; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific

Vorinostat in Treating Patients With Metastatic or Unresectable Solid Tumors or Lymphoma and Liver Dysfunction

ClinicalTrials.gov

2014-02-21

Adult Grade III Lymphomatoid Granulomatosis; Adult Nasal Type Extranodal NK/T-cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Primary Central Nervous System Hodgkin Lymphoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Adult T-cell Leukemia/Lymphoma; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Mycosis Fungoides/Sezary Syndrome; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

PXD101 and 17-N-Allylamino-17-Demethoxygeldanamycin in Treating Patients With Metastatic or Unresectable Solid Tumors or Lymphoma

ClinicalTrials.gov

2013-05-15

Adult Nasal Type Extranodal NK/T-cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Post-transplant Lymphoproliferative Disorder; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Adult T-cell Leukemia/Lymphoma; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Mycosis Fungoides/Sezary Syndrome; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

Tanespimycin and Bortezomib in Treating Patients With Advanced Solid Tumors or Lymphomas

ClinicalTrials.gov

2014-02-21

Adult Grade III Lymphomatoid Granulomatosis; AIDS-related Peripheral/Systemic Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Adult T-cell Leukemia/Lymphoma; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Mycosis Fungoides/Sezary Syndrome; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

Gas dynamics of reactive gases in swirling-type furnace

NASA Astrophysics Data System (ADS)

Akhmetshina, A. I.; Pavlov, G. I.; Sabirzyanov, A. N.; Tikhonov, O. A.

2017-09-01

It is known from the literature that for the complete reaction of two gases (fuel and oxidizer), it is necessary to fulfill three basic conditions: the stoichiometric ratio of reactive gases, qualitative mixing and ensuring the cooling of combustion products without "quenching". Of the above-stated conditions it is more difficult to organize a qualitative mixture formation. This physical process requires additional expenditure of energy flow. In this work we present the results of experimental and theoretical studies of the gas dynamics of a reactive gas mixture in a swirling-type furnace. The design scheme of the furnace includes two reaction zones for combustible components: the first zone is the zone of generation of combustible gases which composition is constant; the second zone of the furnace - zone of a homogeneous combustion reaction.

Cooling of a magmatic system under thermal chaotic mixing

NASA Astrophysics Data System (ADS)

Petrelli, Maurizio; El Omari, Kamal; Le Guer, Yves; Perugini, Diego

2015-04-01

The cooling of a melt undergoing chaotic advection is studied numerically for a magma with a temperature-dependent viscosity in a 2D cavity with moving boundary. Different statistical mixing and energy indicators are used to characterize the efficiency of cooling by thermal chaotic mixing. We show that different cooling rates can be obtained during the thermal mixing even of a single basaltic magmatic batch undergoing chaotic advection. This process can induce complex temperature patterns inside the magma chamber. The emergence of chaotic dynamics strongly affects the temperature field during time and greatly increases the cooling rates. This mechanism has implications for the lifetime of a magmatic body and may favor the appearance of chemical heterogeneities in igneous systems as a result of different crystallization rates. Results from this study also highlight that even a single magma batch can develop, under chaotic thermal advection, complex thermal and therefore compositional patterns resulting from different cooling rates, which can account for some natural features that, to date, have received unsatisfactory explanations. Among them, the production of magmatic enclaves showing completely different cooling histories compared with the host magma, compositional zoning in mineral phases, and the generation of large-scale compositionally zoning observed in many plutons worldwide.

Gas-Enhanced Ultra-High Shear Mixing: A Concept and Applications

NASA Astrophysics Data System (ADS)

Czerwinski, Frank; Birsan, Gabriel

2017-04-01

The processes of mixing, homogenizing, and deagglomeration are of paramount importance in many industries for modifying properties of liquids or liquid-based dispersions at room temperature and treatment of molten or semi-molten alloys at high temperatures, prior to their solidification. To implement treatments, a variety of technologies based on mechanical, electromagnetic, and ultrasonic principles are used commercially or tested at the laboratory scale. In a large number of techniques, especially those tailored toward metallurgical applications, the vital role is played by cavitation, generation of gas bubbles, and their interaction with the melt. This paper describes a novel concept exploring an integration of gas injection into the shear zone with ultra-high shear mixing. As revealed via experiments with a prototype of the cylindrical rotor-stator apparatus and transparent media, gases injected radially through the high-speed rotor generate highly refined bubbles of high concentration directly in the shear zone of the mixer. It is believed that an interaction of large volume of fine gas bubbles with the liquid, superimposed on ultra-high shear, will enhance mixing capabilities and cause superior refining and homogenizing of the liquids or solid-liquid slurries, thus allowing their effective property modification.

Tower reactors for bioconversion of lignocellulosic material

DOEpatents

Nguyen, Quang A.

1999-01-01

An apparatus for enzymatic hydrolysis and fermentation of pretreated lignocellulosic material, in the form of a tower bioreactor, having mixers to achieve intermittent mixing of the material. Precise mixing of the material is important for effective heat and mass transfer requirements without damaging or denaturing the enzymes or fermenting microorganisms. The pretreated material, generally in the form of a slurry, is pumped through the bioreactor, either upwards or downwards, and is mixed periodically as it passes through the mixing zones where the mixers are located. For a thin slurry, alternate mixing can be achieved by a pumping loop which also serves as a heat transfer device. Additional heat transfer takes place through the reactor heat transfer jackets.

Tower reactors for bioconversion of lignocellulosic material

DOEpatents

Nguyen, Quang A.

1998-01-01

An apparatus for enzymatic hydrolysis and fermentation of pretreated lignocellulosic material, in the form of a tower bioreactor, having mixers to achieve intermittent mixing of the material. Precise mixing of the material is important for effective heat and mass transfer requirements without damaging or denaturing the enzymes or fermenting microorganisms. The pretreated material, generally in the form of a slurry, is pumped through the bioreactor, either upwards of downwards, and is mixed periodically as it passes through the mixing zones where the mixers are located. For a thin slurry, alternate mixing can be achieved by a pumping loop which also serves as a heat transfer device. Additional heat transfer takes place through the reactor heat transfer jackets.

Low NO sub x heavy fuel combustor concept program

NASA Technical Reports Server (NTRS)

Russell, P.; Beal, G.; Hinton, B.

1981-01-01

A gas turbine technology program to improve and optimize the staged rich lean low NOx combustor concept is described. Subscale combustor tests to develop the design information for optimization of the fuel preparation, rich burn, quick air quench, and lean burn steps of the combustion process were run. The program provides information for the design of high pressure full scale gas turbine combustors capable of providing environmentally clean combustion of minimally of minimally processed and synthetic fuels. It is concluded that liquid fuel atomization and mixing, rich zone stoichiometry, rich zone liner cooling, rich zone residence time, and quench zone stoichiometry are important considerations in the design and scale up of the rich lean combustor.

MDX-010 in Treating Patients With Recurrent or Refractory Lymphoma

ClinicalTrials.gov

2014-05-22

Adult Grade III Lymphomatoid Granulomatosis; B-cell Chronic Lymphocytic Leukemia; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Testicular Lymphoma; Waldenström Macroglobulinemia

Single-particle characterization of the High Arctic summertime aerosol

NASA Astrophysics Data System (ADS)

Sierau, B.; Chang, R. Y.-W.; Leck, C.; Paatero, J.; Lohmann, U.

2014-01-01

Single-particle mass spectrometric measurements were carried out in the High Arctic north of 80° during summer 2008. The campaign took place onboard the icebreaker Oden and was part of the Arctic Summer Cloud Ocean Study (ASCOS). The instrument deployed was an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) that provides information on the chemical composition of individual particles and their mixing state in real-time. Aerosols were sampled in the marine boundary layer at stations in the open ocean, in the marginal ice zone, and in the pack ice region. The largest fraction of particles detected for subsequent analysis in the size range of the ATOFMS between approximately 200 nm to 3000 nm in diameter showed mass spectrometric patterns indicating an internal mixing state and a biomass burning and/or biofuel source. The majority of these particles were connected to an air mass layer of elevated particle concentration mixed into the surface mixed layer from the upper part of the marine boundary layer. The second largest fraction was represented by sea salt particles. The chemical analysis of the over-ice sea salt aerosol revealed tracer compounds that reflect chemical aging of the particles during their long-range advection from the marginal ice zone, or open waters south thereof prior to detection at the ship. From our findings we conclude that long-range transport of particles is one source of aerosols in the High Arctic. To assess the importance of long-range particle sources for aerosol-cloud interactions over the inner Arctic in comparison to local and regional biogenic primary aerosol sources, the chemical composition of the detected particles was analyzed for indicators of marine biological origin. Only a~minor fraction showed chemical signatures of potentially ocean-derived primary particles of that kind. However, a chemical bias in the ATOFMS's detection capabilities observed during ASCOS might suggest a presence of a particle type of unknown composition and source. In general, the study suffered from low counting statistics due to the overall small number of particles found in this pristine environment, the small sizes of the prevailing aerosol below the detection limit of the ATOFMS and its low hit rate. To our knowledge, this study reports on the first in-situ single-particle mass spectrometric measurements in the marine boundary layer of the High-Arctic pack-ice region.

Single-particle characterization of the high-Arctic summertime aerosol

NASA Astrophysics Data System (ADS)

Sierau, B.; Chang, R. Y.-W.; Leck, C.; Paatero, J.; Lohmann, U.

2014-07-01

Single-particle mass-spectrometric measurements were carried out in the high Arctic north of 80° during summer 2008. The campaign took place onboard the icebreaker Oden and was part of the Arctic Summer Cloud Ocean Study (ASCOS). The instrument deployed was an aerosol time-of-flight mass spectrometer (ATOFMS) that provides information on the chemical composition of individual particles and their mixing state in real time. Aerosols were sampled in the marine boundary layer at stations in the open ocean, in the marginal ice zone, and in the pack ice region. The largest fraction of particles detected for subsequent analysis in the size range of the ATOFMS between approximately 200 and 3000 nm in diameter showed mass-spectrometric patterns, indicating an internal mixing state and a biomass burning and/or biofuel source. The majority of these particles were connected to an air mass layer of elevated particle concentration mixed into the surface mixed layer from the upper part of the marine boundary layer. The second largest fraction was represented by sea salt particles. The chemical analysis of the over-ice sea salt aerosol revealed tracer compounds that reflect chemical aging of the particles during their long-range advection from the marginal ice zone, or open waters south thereof prior to detection at the ship. From our findings we conclude that long-range transport of particles is one source of aerosols in the high Arctic. To assess the importance of long-range particle sources for aerosol-cloud interactions over the inner Arctic in comparison to local and regional biogenic primary aerosol sources, the chemical composition of the detected particles was analyzed for indicators of marine biological origin. Only a minor fraction showed chemical signatures of potentially ocean-derived primary particles of that kind. However, a chemical bias in the ATOFMS's detection capabilities observed during ASCOS might suggest the presence of a particle type of unknown composition and source. In general, the study suffered from low counting statistics due to the overall small number of particles found in this pristine environment, the small sizes of the prevailing aerosol below the detection limit of the ATOFMS, and its low hit rate. To our knowledge, this study reports on the first in situ single-particle mass-spectrometric measurements in the marine boundary layer of the high-Arctic pack ice region.

Whole watershed quantification of net carbon fluxes by erosion and deposition within the Christina River Basin Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Aufdenkampe, A. K.; Karwan, D. L.; Aalto, R. E.; Marquard, J.; Yoo, K.; Wenell, B.; Chen, C.

2012-12-01

We have proposed that the rate at which fresh, carbon-free minerals are delivered to and mix with fresh organic matter determines the rate of carbon preservation at a watershed scale (Aufdenkampe et al. 2011). Although many studies have examined the role of erosion in carbon balances, none consider that fresh carbon and fresh minerals interact. We believe that this mechanism may be a dominant sequestration process in watersheds with strong anthropogenic impacts. Our hypothesis - that the rate of mixing fresh carbon with fresh, carbon-free minerals is a primary control on watershed-scale carbon sequestration - is central to our Christina River Basin Critical Zone Observatory project (CRB-CZO, http://www.udel.edu/czo/). The Christina River Basin spans 1440 km2 from piedmont to Atlantic coastal plain physiographic provinces in the states of Pennsylvania and Delaware, and experienced intensive deforestation and land use beginning in the colonial period of the USA. Here we present a synthesis of multi-disciplinary data from the CRB-CZO on materials as they are transported from sapprolite to topsoils to colluvium to suspended solids to floodplains, wetlands and eventually to the Delaware Bay estuary. At the heart of our analysis is a spatially-integrated, flux-weighted comparison of the organic carbon to mineral surface area ratio (OC/SA) of erosion source materials versus transported and deposited materials. Because source end-members - such as forest topsoils, farmed topsoils, gullied subsoils and stream banks - represent a wide distribution of initial, pre-erosion OC/SA, we quantify source contributions using geochemical sediment fingerprinting approaches (Walling 2005). Analytes used for sediment fingerprinting include: total mineral elemental composition (including rare earth elements), fallout radioisotope activity for common erosion tracers (beryllium-7, beryllium-10, lead-210, cesium-137), particle size distribution and mineral specific surface area, in addition to organic carbon and nitrogen content with stable isotope (13C, 15N) and radiocarbon (14C) abundance to quantify OC/SA and organic carbon sources and mean age. We then use multivariate mixing model analysis to quantify the fractional contribution of each source end-member to each sample of suspended or deposited sediments. Last, we calculate a predicted OC/SA based on source end-member mixing and compare to the measured OC/SA to quantify net change in mineral complexed carbon.

Responses of infaunal populations to benthoscape structure and the potential importance of transition zones

USGS Publications Warehouse

Zajac, R.N.; Lewis, R.S.; Poppe, L.J.; Twichell, D.C.; Vozarik, J.; DiGiacomo-Cohen, M. L.

2003-01-01

Relationships between population abundance and seafloor landscape, or benthoscape, structure were examined for 16 infaunal taxa in eastern Long Island Sound. Based on analyses of a side-scan sonar mosaic, the 19.4-km2 study area was comprised of six distinct large-scale (> km2) benthoscape elements, with varying levels of mesoscale (km2-m2) and small-scale (2) physical and biological habitat heterogeneity. Transition zones among elements varied from ~50 to 200 m in width, comprised ~32% of the benthoscape, and added to overall benthoscape heterogeneity. Population abundances of nine taxa varied significantly among the large-scale elements. Most species were found at high abundances only in one benthoscape element, but three had several foci of elevated abundances. Analyses of population responses to habitat heterogeneity at different spatial scales indicated that abundances of eight taxa varied significantly among spatial scales, but the significant scales were mixed among these species. Relatively large residual variations suggest significant amounts of mesoscale spatial variation were unaccounted for, varying from ~1 km2 to several m2. Responses to transition zones were mixed as well. Abundances of nine taxa varied significantly among transition zones and interiors of benthoscape elements, most with elevated abundances in transition zones. Our results show that infaunal populations exhibit complex and spatially varying patterns of abundance in relation to benthoscape structure and suggest that mesoscale variation may be particularly critical in this regard. Also, transition zones among benthoscape features add considerably to this variation and may be ecological important areas in seafloor environments.

Size-selective mortality of steelhead during freshwater and marine life stages related to freshwater growth in the Skagit River, Washington

USGS Publications Warehouse

Thompson, Jamie N.; Beauchamp, David A.

2014-01-01

We evaluated freshwater growth and survival from juvenile (ages 0–3) to smolt (ages 1–5) and adult stages in wild steelhead Oncorhynchus mykiss sampled in different precipitation zones of the Skagit River basin, Washington. Our objectives were to determine whether significant size-selective mortality (SSM) in steelhead could be detected between early and later freshwater stages and between each of these freshwater stages and returning adults and, if so, how SSM varied between these life stages and mixed and snow precipitation zones. Scale-based size-at-annulus comparisons indicated that steelhead in the snow zone were significantly larger at annulus 1 than those in the mixed rain–snow zone. Size at annuli 2 and 3 did not differ between precipitation zones, and we found no precipitation zone × life stage interaction effect on size at annulus. Significant freshwater and marine SSM was evident between the juvenile and adult samples at annulus 1 and between each life stage at annuli 2 and 3. Rapid growth between the final freshwater annulus and the smolt migration did not improve survival to adulthood; rather, it appears that survival in the marine environment may be driven by an overall higher growth rate set earlier in life, which results in a larger size at smolt migration. Efforts for recovery of threatened Puget Sound steelhead could benefit by considering that SSM between freshwater and marine life stages can be partially attributed to growth attained in freshwater habitats and by identifying those factors that limit growth during early life stages.

Characterizing Three-Dimensional Mixing Process in a River Confluence using Hydro-acoustical Backscatter and Flow Measurement

NASA Astrophysics Data System (ADS)

Son, Geunsoo; Kim, Dongsu; Kim, YoungDo; Lyu, Siwan; Kim, Seojun

2017-04-01

River confluences are zones where two rivers with different geomorphic and hydraulic characteristics amalgamate, resulting in rapid change in terms of flow regime, sediment entrainment and hydraulic geometry. In these confluence zones, the flow structure is basically complicated responded with concurrent mixing of physical and chemical aquatic properties, and continuous channel morphology could be changed due to erosion and sedimentation. In addition, the confluences are regions in which two rivers join and play an important role in river ecology. In order to characterize the mixing process of confluence for understanding the impacts of a river on the other river, therefore, it has been crucial to analyze the spatial mixing patterns for main streams depending on various inflow conditions of tributaries. However, most conventional studies have mostly relied upon hydraulic or water quality numerical models for understanding mixing pattern analysis of confluences, due to the difficulties to acquire a wide spatial range of in-situ data especially for characterizing this kind of mixing process. Even with intensive in-situ measurements, those researches tended to focus mainly on the hydraulic characteristics such as the flow and morphological complexity of confluence, so that very few studies comprehensively included sediment variation with flow at the same time. In this study, subsequently, flow and sediment mixing characteristics were concurrently investigated in the confluence between Nakdong and Nam river in South Korea, where it has been frequently questioned to determine how Nam river affects Nakdong river that recently have suffered various environmental problems such as green algae bloom and erosion/deposition in the confluence. We basically examined the mixing characteristics of confluence by using acoustic Doppler current profilers (ADCPs) which were used to measure hydraulic factors such as flow rate and depth, as well as measuring the suspended sediment concentration by using acoustic backscatter. Cross-sectional ADCP measurements in a confluence were collected with high spatial resolution in order to analyze the details of spatial distribution in the perspective of the three-dimensional mixing patterns of flow and sediment, where backscatters (or SNR) measured from ADCPs were used to track sediment mixing assuming that it could be a surrogate to estimate the suspended sediment concentration. Raw backscatter data were corrected by considering the beam spreading and absorption by water. Also, an optical Laser diffraction instrument (LISST) was used to verify the method of acoustic backscatter and to collect the particle size distribution of main stream and tributary. In addition, image-based spatial distributions of sediment mixture in the confluence were monitored in various flow conditions by using an unmanned aerial vehicle (UAV), which were compared with the spatial distribution of acoustic backscatter. As results, we found that when acoustic backscatter and flow measurements by ADCPs were well processed, they could be proper indicators to identify the spatial patterns of the three-dimensional mixing process between two rivers.

The Causes and Evolutionary Consequences of Mixed Singing in Two Hybridizing Songbird Species (Luscinia spp.)

PubMed Central

Vokurková, Jana; Petrusková, Tereza; Reifová, Radka; Kozman, Alexandra; Mořkovský, Libor; Kipper, Silke; Weiss, Michael; Reif, Jiří; Dolata, Paweł T.; Petrusek, Adam

2013-01-01

Bird song plays an important role in the establishment and maintenance of prezygotic reproductive barriers. When two closely related species come into secondary contact, song convergence caused by acquisition of heterospecific songs into the birds’ repertoires is often observed. The proximate mechanisms responsible for such mixed singing, and its effect on the speciation process, are poorly understood. We used a combination of genetic and bioacoustic analyses to test whether mixed singing observed in the secondary contact zone of two passerine birds, the Thrush Nightingale (Luscinia luscinia) and the Common Nightingale (L. megarhynchos), is caused by introgressive hybridization. We analysed song recordings of both species from allopatric and sympatric populations together with genotype data from one mitochondrial and seven nuclear loci. Semi-automated comparisons of our recordings with an extensive catalogue of Common Nightingale song types confirmed that most of the analysed sympatric Thrush Nightingale males were ‘mixed singers’ that use heterospecific song types in their repertoires. None of these ‘mixed singers’ possessed any alleles introgressed from the Common Nightingale, suggesting that they were not backcross hybrids. We also analysed songs of five individuals with intermediate phenotype, which were identified as F1 hybrids between the Thrush Nightingale female and the Common Nightingale male by genetic analysis. Songs of three of these hybrids corresponded to the paternal species (Common Nightingale) but the remaining two sung a mixed song. Our results suggest that although hybridization might increase the tendency for learning songs from both parental species, interspecific cultural transmission is the major proximate mechanism explaining the occurrence of mixed singers among the sympatric Thrush Nightingales. We also provide evidence that mixed singing does not substantially increase the rate of interspecific hybridization and discuss the possible adaptive value of this phenomenon in nightingales. PMID:23577089

Denitrification in the Arabian Sea: A 3D ecosystem modelling study

NASA Astrophysics Data System (ADS)

Anderson, Thomas R.; Ryabchenko, Vladimir A.; Fasham, Michael J. R.; Gorchakov, Victor A.

2007-12-01

A three-dimensional hydrodynamic-ecosystem model was used to examine the factors determining the spatio-temporal distribution of denitrification in the Arabian Sea. The ecosystem model includes carbon and nitrogen as currencies, cycling of organic matter via detritus and dissolved organic matter, and both remineralization and denitrification as sinks for material exported below the euphotic zone. Model results captured the marked seasonality in plankton dynamics of the region, with characteristic blooms of chlorophyll in the coastal upwelling regions and central Arabian Sea during the southwest monsoon, and also in the northern Arabian Sea during the northeast monsoon as the mixed layer shoals. Predicted denitrification was 26.2 Tg N yr -1,the greatest seasonal contribution being during the northeast monsoon when primary production is co-located with the zone of anoxia. Detritus was the primary organic substrate consumed in denitrification (97%), with a small (3%) contribution by dissolved organic matter. Denitrification in the oxygen minimum zone was predicted to be fuelled almost entirely by organic matter supplied by particles sinking vertically from the euphotic zone above (0.73 mmol N m -2 d -1) rather than from lateral transport of organic matter from elsewhere in the Arabian Sea (less than 0.01 mmol N m -2 d -1). Analysis of the carbon budget in the zone of denitrification (north of 10°N and east of 55°E) indicates that the modelled vertical export flux of detritus, which is similar in magnitude to estimates from field data based on the 234Th method, is sufficient to account for measured bacterial production below the euphotic zone in the Arabian Sea.

Solute mixing regulates heterogeneity of mineral precipitation in porous media: Effect of Solute Mixing on Precipitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cil, Mehmet B.; Xie, Minwei; Packman, Aaron I.

Synchrotron X-ray microtomography was used to track the spatiotemporal evolution of mineral precipitation and the consequent alteration of the pore structure. Column experiments were conducted by injecting CaCl2 and NaHCO3 solutions into granular porous media either as a premixed supersaturated solution (external mixing) or as separate solutions that mixed within the specimen (internal mixing). The two mixing modes produced distinct mineral growth patterns. While internal mixing promoted transverse heterogeneity with precipitation at the mixing zone, external mixing favored relatively homogeneous precipitation along the flow direction. The impact of precipitation on pore water flow and permeability was assessed via 3-D flowmore » simulations, which indicated anisotropic permeability evolution for both mixing modes. Under both mixing modes, precipitation decreased the median pore size and increased the skewness of the pore size distribution. Such similar pore-scale evolution patterns suggest that the clogging of individual pores depends primarily on local supersaturation state and pore geometry.« less

Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets.

PubMed

Pantelic, J; Tham, K W; Licina, D

2015-12-01

The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal manikin at distances between 1 and 4 m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure. Exposure to cough droplets was reduced with increasing distance between cough source and exposed occupant. The results from this study show that an advanced air distribution system such as personalized ventilation reduces exposure to cough-released droplets better than commonly applied overhead mixing ventilation. This work can inform HVAC engineers about different aspects of air distribution systems’ performance and can serve as an aid in making critical design decisions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comments on the Parameters and Processes that Affect the Preservation Potential and Style of Oblique-Divergent Plate Boundaries

NASA Astrophysics Data System (ADS)

Umhoefer, P. J.

2014-12-01

Oblique-divergent or transtensional zones present particular challenges in ancient belts because of the poor preservation potential of the thinned continental crust and young oceanic crust. Many oblique belts will preferentially preserve their boundary zones that lie within continents rather than the main plate boundary zone, which will be at a much lower elevation and composed of denser crust. Zones of tectonic escape or strike-slip overprinting of arcs or plateaus deform continental crust and may be better preserved. Here I highlight parameters and processes that have major effects on oblique divergent belts. Strain partitioning is common, but not ubiquitous, along and across oblique boundaries; the causes of partitioning are not always clear and make this especially vexing for work in ancient belts. Partitioning causes complexity in the patterns of structures at all scales. Inherited structures commonly determine the orientation and style of structures along oblique boundaries and can control the pattern of faults across transtensional belts. Regionally, inherited trends of arcs or other 1000-km-scale features can control boundary structures. Experiments and natural examples suggest that oblique boundary zones contain less of a record of strike-slip faulting and more extensional structures. The obliquity of divergence produces predictable families of structures that typify (i) strike-slip dominated zones (obliquity <~20°), (ii) mixed zones (~20° - ~35°), and (iii) extension dominated zones (>~35°). The combination of partitioning and mixed structures in oblique zones means that the boundaries of belts with large-magnitude strike-slip faulting will commonly preserve little of no record of that faulting history. Plate boundaries localize strain onto the main plate boundary structures from the broader plate boundary and therefore the boundary zones commonly preserve the earlier structures more than later structures, a major problem in interpreting ancient belts. Sediment input is critical in some oblique plate boundaries because these belts become more pronounced sediment sinks over time. The evolving topography of oblique boundaries means that they have great variability of sediment flux into differing parts of the system; large rivers enter these belts only in special circumstances.

Brentuximab Vedotin + Rituximab as Frontline Therapy for Pts w/ CD30+ and/or EBV+ Lymphomas

ClinicalTrials.gov

2015-04-28

Adult Grade III Lymphomatoid Granulomatosis; Adult Nasal Type Extranodal NK/T-cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Contiguous Stage II Adult Burkitt Lymphoma; Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Contiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Contiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Contiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Contiguous Stage II Adult Lymphoblastic Lymphoma; Contiguous Stage II Grade 1 Follicular Lymphoma; Contiguous Stage II Grade 2 Follicular Lymphoma; Contiguous Stage II Grade 3 Follicular Lymphoma; Contiguous Stage II Mantle Cell Lymphoma; Contiguous Stage II Marginal Zone Lymphoma; Contiguous Stage II Small Lymphocytic Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Epstein-Barr Virus Infection; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Hepatosplenic T-cell Lymphoma; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Burkitt Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Adult Lymphoblastic Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Noncutaneous Extranodal Lymphoma; Peripheral T-cell Lymphoma; Post-transplant Lymphoproliferative Disorder; Progressive Hairy Cell Leukemia, Initial Treatment; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage I Adult Burkitt Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Mixed Cell Lymphoma; Stage I Adult Diffuse Small Cleaved Cell Lymphoma; Stage I Adult Hodgkin Lymphoma; Stage I Adult Immunoblastic Large Cell Lymphoma; Stage I Adult Lymphoblastic Lymphoma; Stage I Adult T-cell Leukemia/Lymphoma; Stage I Cutaneous T-cell Non-Hodgkin Lymphoma; Stage I Grade 1 Follicular Lymphoma; Stage I Grade 2 Follicular Lymphoma; Stage I Grade 3 Follicular Lymphoma; Stage I Mantle Cell Lymphoma; Stage I Marginal Zone Lymphoma; Stage I Small Lymphocytic Lymphoma; Stage IA Mycosis Fungoides/Sezary Syndrome; Stage IB Mycosis Fungoides/Sezary Syndrome; Stage II Adult Hodgkin Lymphoma; Stage II Adult T-cell Leukemia/Lymphoma; Stage II Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IIA Mycosis Fungoides/Sezary Syndrome; Stage IIB Mycosis Fungoides/Sezary Syndrome; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Adult T-cell Leukemia/Lymphoma; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Small Lymphocytic Lymphoma; Stage IIIA Mycosis Fungoides/Sezary Syndrome; Stage IIIB Mycosis Fungoides/Sezary Syndrome; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma; Stage IVA Mycosis Fungoides/Sezary Syndrome; Stage IVB Mycosis Fungoides/Sezary Syndrome; T-cell Large Granular Lymphocyte Leukemia; Testicular Lymphoma; Untreated Hairy Cell Leukemia; Waldenström Macroglobulinemia

Rituximab in Preventing Acute Graft-Versus-Host Disease in Patients Undergoing a Donor Stem Cell Transplant for Hematologic Cancer

ClinicalTrials.gov

2017-09-29

Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Nasal Type Extranodal NK/T-cell Lymphoma; Blastic Phase Chronic Myelogenous Leukemia; Contiguous Stage II Adult Burkitt Lymphoma; Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Contiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Contiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Contiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Contiguous Stage II Adult Lymphoblastic Lymphoma; Contiguous Stage II Grade 1 Follicular Lymphoma; Contiguous Stage II Grade 2 Follicular Lymphoma; Contiguous Stage II Grade 3 Follicular Lymphoma; Contiguous Stage II Mantle Cell Lymphoma; Contiguous Stage II Marginal Zone Lymphoma; Contiguous Stage II Small Lymphocytic Lymphoma; de Novo Myelodysplastic Syndromes; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Graft Versus Host Disease; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Burkitt Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Adult Lymphoblastic Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Relapsing Chronic Myelogenous Leukemia; Secondary Myelodysplastic Syndromes; Splenic Marginal Zone Lymphoma; Stage I Adult Burkitt Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Mixed Cell Lymphoma; Stage I Adult Diffuse Small Cleaved Cell Lymphoma; Stage I Adult Immunoblastic Large Cell Lymphoma; Stage I Adult Lymphoblastic Lymphoma; Stage I Adult T-cell Leukemia/Lymphoma; Stage I Chronic Lymphocytic Leukemia; Stage I Cutaneous T-cell Non-Hodgkin Lymphoma; Stage I Grade 1 Follicular Lymphoma; Stage I Grade 2 Follicular Lymphoma; Stage I Grade 3 Follicular Lymphoma; Stage I Mantle Cell Lymphoma; Stage I Marginal Zone Lymphoma; Stage I Mycosis Fungoides/Sezary Syndrome; Stage I Small Lymphocytic Lymphoma; Stage II Adult T-cell Leukemia/Lymphoma; Stage II Chronic Lymphocytic Leukemia; Stage II Cutaneous T-cell Non-Hodgkin Lymphoma; Stage II Mycosis Fungoides/Sezary Syndrome; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Adult T-cell Leukemia/Lymphoma; Stage III Chronic Lymphocytic Leukemia; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Mycosis Fungoides/Sezary Syndrome; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Chronic Lymphocytic Leukemia; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Myeloid Leukemia; Waldenström Macroglobulinemia

Vorinostat, Tacrolimus, and Methotrexate in Preventing GVHD After Stem Cell Transplant in Patients With Hematological Malignancies

ClinicalTrials.gov

2015-10-13

Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Grade III Lymphomatoid Granulomatosis; B-cell Chronic Lymphocytic Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Myelomonocytic Leukemia; Chronic Phase Chronic Myelogenous Leukemia; Contiguous Stage II Adult Burkitt Lymphoma; Contiguous Stage II Adult Diffuse Large Cell Lymphoma; Contiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Contiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Contiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Contiguous Stage II Adult Lymphoblastic Lymphoma; Contiguous Stage II Grade 1 Follicular Lymphoma; Contiguous Stage II Grade 2 Follicular Lymphoma; Contiguous Stage II Grade 3 Follicular Lymphoma; Contiguous Stage II Mantle Cell Lymphoma; Contiguous Stage II Marginal Zone Lymphoma; Contiguous Stage II Small Lymphocytic Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Graft Versus Host Disease; Intraocular Lymphoma; Myelodysplastic Syndrome With Isolated Del(5q); Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Burkitt Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Adult Lymphoblastic Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Post-transplant Lymphoproliferative Disorder; Primary Central Nervous System Hodgkin Lymphoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Anemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Ringed Sideroblasts; Refractory Chronic Lymphocytic Leukemia; Refractory Cytopenia With Multilineage Dysplasia; Refractory Hairy Cell Leukemia; Relapsing Chronic Myelogenous Leukemia; Secondary Central Nervous System Hodgkin Lymphoma; Secondary Central Nervous System Non-Hodgkin Lymphoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage I Adult Burkitt Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Mixed Cell Lymphoma; Stage I Adult Diffuse Small Cleaved Cell Lymphoma; Stage I Adult Hodgkin Lymphoma; Stage I Adult Immunoblastic Large Cell Lymphoma; Stage I Adult Lymphoblastic Lymphoma; Stage I Chronic Lymphocytic Leukemia; Stage I Grade 1 Follicular Lymphoma; Stage I Grade 2 Follicular Lymphoma; Stage I Grade 3 Follicular Lymphoma; Stage I Mantle Cell Lymphoma; Stage I Marginal Zone Lymphoma; Stage I Small Lymphocytic Lymphoma; Stage II Adult Hodgkin Lymphoma; Stage II Chronic Lymphocytic Leukemia; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Chronic Lymphocytic Leukemia; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Chronic Lymphocytic Leukemia; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma; Testicular Lymphoma; Waldenström Macroglobulinemia

Groundwater ages from the freshwater zone of the Edwards aquifer, Uvalde County, Texas—Insights into groundwater flow and recharge

USGS Publications Warehouse

Hunt, Andrew G.; Landis, Gary P.; Faith, Jason R.

2016-02-23

Tritium–helium-3 groundwater ages of the Edwards aquifer in south-central Texas were determined as part of a long-term study of groundwater flow and recharge in the Edwards and Trinity aquifers. These ages help to define groundwater residence times and to provide constraints for calibration of groundwater flow models. A suite of 17 samples from public and private supply wells within Uvalde County were collected for active and noble gases, and for tritium–helium-3 analyses from the confined and unconfined parts of the Edwards aquifer. Samples were collected from monitoring wells at discrete depths in open boreholes as well as from integrated pumped well-head samples. The data indicate a fairly uniform groundwater flow system within an otherwise structurally complex geologic environment comprised of regionally and locally faulted rock units, igneous intrusions, and karst features within carbonate rocks. Apparent ages show moderate, downward average, linear velocities in the Uvalde area with increasing age to the east along a regional groundwater flow path. Though the apparent age data show a fairly consistent distribution across the study area, many apparent ages indicate mixing of both modern (less than 60 years) and premodern (greater than 60 years) waters. This mixing is most evident along the “bad water” line, an arbitrary delineation of 1,000 milligrams per liter dissolved solids that separates the freshwater zone of the Edwards aquifer from the downdip saline water zone. Mixing of modern and premodern waters also is indicated within the unconfined zone of the aquifer by high excess helium concentrations in young waters. Excess helium anomalies in the unconfined aquifer are consistent with possible subsurface discharge of premodern groundwater from the underlying Trinity aquifer into the younger groundwater of the Edwards aquifer.

Spatial variability of primary organic sources regulates ichthyofauna distribution despite seasonal influence in Terminos lagoon and continental shelf of Campeche, Mexico

NASA Astrophysics Data System (ADS)

Romo Rios, J. A.; Aguíñiga-García, S.; Sanchez, A.; Zetina-Rejón, M.; Arreguín-Sánchez, F.; Tripp-Valdéz, A.; Galeana-Cortazár, A.

2013-05-01

Human activities have strong impacts on coastal ecosystems functioning through their effect on primary organic sources distributions and resulting biodiversity. Hence, it appears to be of utmost importance to quantify contribution of primary producers to sediment organic matter (SOM) spatial variability and its associated ichthyofauna. The Terminos lagoon (Gulf of Mexico) is a tropical estuary severely impacted by human activities even though of primary concern for its biodiversity, its habitats, and its resource supply. Stable isotope data (d13C, d15N) from mangrove, seaweed, seagrass, phytoplankton, ichthyofauna and SOM were sampled in four zones of the lagoon and the continental shelf through windy (November to February), dry (March to June) and rainy (July to October) seasons. Stable Isotope Analysis in R (SIAR) mixing model were used to determine relative contributions of the autotrophic sources to the ichthyofauna and SOM. Analysis of variance of ichthyofauna isotopic values showed significant differences (P < 0.001) in the four zones of lagoon despite the variability introduced by the windy, dry and rainy seasons. In lagoons rivers discharge zone, the mangrove contribution to ichthyofauna was 40% and 84% to SOM. Alternative use of habitat by ichthyofauna was evidenced since in the deep area of the lagoon (4 m), the contribution of mangrove to fish is 50%, and meanwhile contribution to SOM is only 77%. Although phytoplankton (43%) and seaweed (41%) contributions to the adjacent continental shelf ichthyofauna were the main organic sources, there was 37% mangrove contribution to SOM, demonstrating conspicuous terrigenous influence from lagoon ecosystem. Our results point toward organic sources spatial variations that regulate fish distribution. In Terminos lagoon, significant correlation (p-value = 0.2141 and r=0.79) of Ariopsis felis and Sphoeroides testudineus abundances and seaweed and seagrasses contributions (30-35%) during both dry and rainy seasons, evidence that spatial variability organic sources could be central for the state of equilibrium of ecosystems. Keywords: sediment organic matter, mangrove, ecosystems, mixing model, trophic structure

Genetic implications of the trace element distribution pattern in the upper knox carbonate rocks, copper ridge district, East Tennessee

NASA Astrophysics Data System (ADS)

Churnet, Habte G.; Misra, Kula C.

1981-11-01

The Lower Ordovician, Upper Knox Group rocks (the Kingsport and Mascot formations) in the Copper Ridge district consist predominantly of fine-grained dolostones, medium and coarser grained dolostones, and limestones. Dolomite crystals of medium and coarser grained dolostones show up to eight cathodoluminescent zones of variable width and intensity. Electron microprobe analyses indicate that the zoning is related to variation in Fe/Mn ratios, the brighter luminescent zones corresponding to lower ratios. Superposed on this growth zoning is a compositional zoning characterized by a general increase in Fe from core to rim of individual dolomite crystals. Field and petrographic studies (Churnet, 1979; Churnet et al., 1981) indicate that the fine-grained dolostones formed in supratidal to upper intratidal environments, whereas the precursor lime muds of the limestones as well as of the medium and coarser grained dolostones formed in shallow subtidal to lower intertidal environments. The large areal extent of the dolostones must have required a regionally abundant source of Mg such as marine water. Yet, both limestones and dolostones have low Na and Sr contents suggestive of their formation in solutions more dilute than normal marine water. It is proposed that the fine-grained dolostones formed by aggradation of initially very fine-grained dolostones in presence of fresh water, and that the limestones stabilized and the medium and coarser grained dolostones formed in environments of mixed marine and fresh waters. Considered in the light of ordering of partition coefficients, such a mixing model can account for the observed correlation pattern of trace elements (especially, SMn and SrFe) as well as the Fe distribution in the zoned dolomite crystals. Variation of the partition coefficient of Mn due to fluctuations in the relative proportions of fresh and marine waters in the diagenetic solution may explain the different Fe/Mn ratios observed in the growth zones (luminescence bands) of zoned dolomite crystals.

Effects of Temperature and Air Density Profiles on Ozone Lidar Retrievals

NASA Astrophysics Data System (ADS)

Kirgis, G.; Langford, A. O.; Senff, C. J.; Alvarez, R. J. _II, II

2017-12-01

The recent reduction in the primary U.S. National Ambient Air Quality Standard (NAAQS) for ozone (O3) from 75 to 70 parts-per-billion by volume (ppbv) adds urgency to the need for better understanding of the processes that control ground-level concentrations in the United States. While ground-based in situ sensors are capable of measuring ozone levels, they don't give any insight into upper air transport and mixing. Differential absorption lidars such as the NOAA/ESRL Tunable Optical Profiler for Aerosol and oZone (TOPAZ) measure continuous vertical ozone profiles with high spatial and temporal resolution. However, the retrieved ozone mixing ratios depend on the temperature and air density profiles used in the analysis. This study analyzes the ozone concentrations for seven field campaigns from 2013 to 2016 to evaluate the impact of the assumed pressure and temperature profiles on the ozone mixing ratio retrieval. Pressure and temperature profiles from various spatial and temporal resolution models (Modern Era Retrospective-Analysis for Research and Applications, NCEP/NCAR Reanalysis, NCEP North American Regional Reanalysis, Rapid Refresh, and High-Resolution Rapid Refresh) are compared to reference ozone profiles created with pressure and temperature profiles from ozonesondes launched close to the TOPAZ measurement site. The results show significant biases with respect to time of day and season, altitude, and location of the model-extracted profiles. Limitations and advantages of all datasets used will also be discussed.

Efficacy of bayer suspend poly zone against stable flies and house flies when applied to trigger royal cloth

USDA-ARS?s Scientific Manuscript database

METHODS: PolyZone (PZ)(Deltamethrin 4.75% AI) was mixed with water according to label instructions (45.4 ml per 3.79 liters H2O = 0.06% solution) for application to 10 x 10 cm squares of blue Trigger-Royal Box fabric (65% polyester and 35% cotton, Galey & Lord, Inc., New York). PZ was applied to run...

The assessment of waters ecological state of the Crimea coastal near high-rise construction zones

NASA Astrophysics Data System (ADS)

Vetrova, Natalya; Ivanenko, Tatyana; Mannanov, Emran

2018-03-01

The relevance of our study is determined by the significant level of coastal sea waters pollution by sewage near high-rise construction zones, which determines the violation of the sanitary and hygienic of sea waters `characteristics and limits the possibilities for organizing recreational activities. The purpose of this study is to identify the ecological state of the marine aquatic area by the example of the Western Crimea near high-rise construction zones. The studies confirmed that the recreational and coastal area wastewater is intensely mixed with seawater, as a result, the pollution in the coastal strip of the sea in the area of deep water discharges sharply decrease. This happens because of water rapid rise to the surface and under the influence of the continuous movement of sea water huge masses with deep-water discharge, fresh wastewater is actively mixed with sea water. However, with no doubt, it is inadmissible to discharge sewage into the sea directly from the shore, but only at the estimated distance from the coast. The materials of the article can be useful for the management bodies and organizations involved in monitoring the quality of the coastal zone of the sea, teachers and students of higher educational institutions when assessing the ecological situation of the territories.

Transient Liquid-Phase Diffusion Bonding of Aluminum Metal Matrix Composite Using a Mixed Cu-Ni Powder Interlayer

NASA Astrophysics Data System (ADS)

Maity, Joydeep; Pal, Tapan Kumar

2012-07-01

In the present study, the transient liquid-phase diffusion bonding of an aluminum metal matrix composite (6061-15 wt.% SiCp) has been investigated for the first time using a mixed Cu-Ni powder interlayer at 560 °C, 0.2 MPa, for different holding times up to 6 h. The microstructure of the isothermally solidified zone contains equilibrium precipitate CuAl2, metastable precipitate Al9Ni2 in the matrix of α-solid solution along with the reinforcement particles (SiC). On the other hand, the microstructure of the central bond zone consists of equilibrium phases such as NiAl3, Al7Cu4Ni and α-solid solution along with SiC particles (without any segregation) and the presence of microporosities. During shear test, the crack originates from microporosities and propagates along the interphase interfaces resulting in poor bond strength for lower holding times. As the bonding time increases, with continual diffusion, the structural heterogeneity is diminished, and the microporosities are eliminated at the central bond zone. Accordingly, after 6-h holding, the microstructure of the central bond zone mainly consists of NiAl3 without any visible microporosity. This provides a joint efficiency of 84% with failure primarily occurring through decohesion at the SiC particle/matrix interface.

Petrologic and chemical changes in ductile shear zones as a function of depth in the continental crust

NASA Astrophysics Data System (ADS)

Yang, Xin-Yue

Petrologic and geochemical changes in ductile shear zones are important for understanding deformational and geochemical processes of the continental crust. This study examines three shear zones that formed under conditions varying from lower greenschist facies to upper amphibolite facies in order to document the petrologic and geochemical changes of deformed rocks at various metamorphic grades. The studied shear zones include two greenschist facies shear zones in the southern Appalachians and an upper amphibolite facies shear zone in southern Ontario. The mylonitic gneisses and mylonites in the Roses Mill shear zone of central Virginia are derived from a ferrodiorite protolith and characterized by a lower greenschist facies mineral assemblage. Both pressure solution and recrystallization were operative deformation mechanisms during mylonitization in this shear zone. Strain-driven dissolution and solution transfer played an important role in the mobilization of felsic components (Si, Al, K, Na, and Ca). During mylonitization, 17% to 32% bulk rock volume losses of mylonites are mainly attributed to removal of these mobile felsic components by a fluid phase. Mafic components (Fe, Mg, Ti, Mn and P) and trace elements, REE, Y, V and Sc, were immobile. At Rosman, North Carolina, the Brevard shear zone (BSZ) shows a deformational transition from the coarse-grained Henderson augen gneiss (HAG) to proto-mylonite, mylonite and ultra-mylonite. The mylonites contain a retrograde mineral assemblage as a product of fluid-assisted chemical breakdown of K-feldspar and biotite at higher greenschist facies conditions. Recrystallization and intra-crystalline plastic deformation are major deformation mechanisms in the BSZ. Fluid-assisted mylonitization in the BSZ led to 6% to 23% bulk volume losses in mylonites. During mylonitization, both major felsic and mafic elements and trace elements, Rb, Sr, Zr, V, Sc, and LREE were mobile; however, the HREEs were likely immobile. A shear zone in the Parry Sound domain, Ontario, formed at upper amphibolite facies conditions. The deformation process of the shear zone involves fully plastic deformation and high-temperature dynamic recrystallization and annealing recovery of both quartz and plagioclase. Geochemical evidence indicates that the chemical changes in the deformed rocks resulted from mixing of mafic and felsic layers together with fluid-assisted mass transfer within the shear zone. A geochemical model that incorporates closed-system two-component mixing with open-system mass transfer can well explain the observed major and trace element data.

Mixing and mingling in Iceland: The origin of a diverse suite of Tertiary lavas

NASA Astrophysics Data System (ADS)

Jordan, B. T.

2006-12-01

A sequence of intermediate and silicic volcanic units occurs within a stratigraphic package dominated by moderately evolved tholeiitic basalts in the mountains Laxardalsfjoll and Langadalsfjall in the southern Skagi Peninsula of north-central Iceland. This sequence consists of several minor rhyolite and dacite lavas directly overlain by a voluminous (>3 km3) litholigically diverse andesite to rhyolite lava flow Above this flow is a basaltic andesite to dacite lava, or lavas (mapping not complete), and the sequence is capped by an extensive rhyolite lava. Pyroclastic deposits, including one welded tuff, occur within the sequence. The sequence was erupted at 7.8 Ma, not long before the abandonment of the Skagi-Snaefellsnes rift zone in which it was erupted. The rhyolite lavas are generally aphyric. The lower rhyolites are of variable composition (71-75% SiO2) and the upper is a high-silica rhyolite (75-76% SiO2). The lower dacite and upper basaltic andesite to dacite lava(s) are aphyric and plot on a linear mixing trend between well defined end-members, a moderately evolved basalt and a high-silica rhyolite. The most anomalous unit is the andesite-rhyolite lava. It is lithologically heterogeneous with <<1% to 20% coarse (up to 3 cm) nearly equant plagioclase phenocrysts. Lithologies commonly vary across sharp borders within the flow, with domains of different lithologies being up to 10s of m in extent. The coarse plagioclase phenocrysts are calcic, up to An87 indicating an origin in basaltic magma. The whole rock composition varies from andesite (58% SiO2) to rhyolite (70% SiO2). Silica content is inversely correlated with phenocryst abundance, but can not be explained by phenocrysts alone. A wide range of mixing and mingling textures are observed at mesoscopic and microscopic scales. Major and trace element variations are quite distinct from the other mixed unit and indicate that the end members of mixing are a plagioclase-rich basalt and a range of silicic compositions from dacite to low-silica rhyolite. A candidate for the mafic end member of mixing is a plagioclase-ultraphyric basalt mapped in Vatnsdalsfjall (~10 km away). It has similar coarse equant plagioclase phenocrysts (up to 35%), with identical An-contents and distinctive patterns of inclusions. I propose that a dike that fed this lava also propagated at depth into a zoned dacite-rhyolite magma chamber, similar to the AD 1480 propagation of the Veidivotn fissure into the Torfajokull caldera. This triggered a large eruption from the zone of mingling/mixing, followed by a significant eruption from the evolved upper portion of the magma chamber. The diverse underlying small-volume rhyolites had been the normal products erupted from the zoned silicic magma chamber. The origin of the second, basaltic andesite to dacite, mixing trend is equivocal. The lavas constituting this trend occur immediately below and above the porphyritic lava suggesting that mixing between normal tholeiite and high-silica rhyolite magmas was ongoing in the upper part of the magma chamber at the time of the main eruption.

Characterization and impact of "dead-zone" eddies in the tropical Northeast Atlantic Ocean

NASA Astrophysics Data System (ADS)

Schuette, Florian; Karstensen, Johannes; Krahmann, Gerd; Hauss, Helena; Fiedler, Björn; Brandt, Peter; Visbeck, Martin; Körtzinger, Arne

2016-04-01

Localized open-ocean low-oxygen dead-zones in the tropical Northeast Atlantic are recently discovered ocean features that can develop in dynamically isolated water masses within cyclonic eddies (CE) and anticyclonic modewater eddies (ACME). Analysis of a comprehensive oxygen dataset obtained from gliders, moorings, research vessels and Argo floats shows that eddies with low oxygen concentrations at 50-150 m depths can be found in surprisingly high numbers and in a large area (from about 5°N to 20°N, from the shelf at the eastern boundary to 30°W). Minimum oxygen concentrations of about 9 μmol/kg in CEs and close to anoxic concentrations (< 1 μmol/kg) in ACMEs were observed. In total, 495 profiles with oxygen concentrations below the minimum background concentration of 40 μmol/kg could be associated with 27 independent "dead-zone" eddies (10 CEs; 17 ACMEs). The low oxygen concentration right beneath the mixed layer has been attributed to the combination of high productivity in the surface waters of the eddies and the isolation of the eddies' cores. Indeed eddies of both types feature a cold sea surface temperature anomaly and enhanced chlorophyll concentrations in their center. The oxygen minimum is located in the eddy core beneath the mixed layer at around 80 m depth. The mean oxygen anomaly between 50 to 150 m depth for CEs (ACMEs) is -49 (-81) μmol/kg. Eddies south of 12°N carry weak hydrographic anomalies in their cores and seem to be generated in the open ocean away from the boundary. North of 12°N, eddies of both types carry anomalously low salinity water of South Atlantic Central Water origin from the eastern boundary upwelling region into the open ocean. This points to an eddy generation near the eastern boundary. A conservative estimate yields that around 5 dead-zone eddies (4 CEs; 1 ACME) per year entering the area north of 12°N between the Cap Verde Islands and 19°W. The associated contribution to the oxygen budget of the shallow oxygen minimum zone in that area is about -10.3 (-3.0) μmol/kg/yr for CEs (ACMEs). The consumption within these eddies represents an essential part of the total consumption in the open tropical Northeast Atlantic Ocean and might be partly responsible for the formation of the shallow oxygen minimum zone.

Yttrium Y 90 Ibritumomab Tiuxetan, Fludarabine, Radiation Therapy, and Donor Stem Cell Transplant in Treating Patients With Relapsed or Refractory Non-Hodgkin's Lymphoma

ClinicalTrials.gov

2017-04-17

B-cell Chronic Lymphocytic Leukemia; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma; Waldenström Macroglobulinemia

Porosity development in coastal carbonate aquifers

USGS Publications Warehouse

Sanford, W.E.; Konikow, Leonard F.

1989-01-01

Combines geochemical mixing theory with the hydrodynamics of fresh-water-salt-water mixing zones in a coupled reaction-transport model. Results from the reaction-path model PHREEQE are used with a variable-density groundwater flow and solute-transport model to simulate an idealized cross section of a coastal carbonate aquifer. The dissolution process is sensitive to fresh-water chemistry, groundwater velocities, and sea-level movement. -from Authors

Preferential flow and mixing process in the chemical recharge in subsurface catchments: observations and modeling

NASA Astrophysics Data System (ADS)

Gascuel-Odoux, C.; Rouxel, M.; Molenat, J.; Ruiz, L.; Aquilina, L.; Faucheux, M.; Labasque, T.; Sebilo, M.

2012-04-01

Shallow groundwater that develops on hillslopes is the main compartment in headwater catchments for flow and solute transport to rivers. Although spatial and temporal variations in its chemical composition are reported in the literature, there is no coherent description of the way these variations are organized, nor is there an accepted conceptual model for the recharge mechanisms and flows in the groundwater involved. We instrumented an intensive farming and subsurface dominant catchment located in Oceanic Western Europe (Kerbernez, Brittany, France), a headwater catchment included in the Observatory for Research on Environment AgrHyS (Agro-Hydro-System) and a part of the French Network of catchments for environmental research (SOERE RBV focused on the Critical Zone). These systems are strongly constrained by anthropogenic pressures (agriculture) and are characterized by a clear non-equilibrium status. A network of 42 nested piezometers was installed along a 200 m hillslope allowing water sampling along two transects in the permanent water table as well as in what we call the "fluctuating zone", characterized by seasonal alternance of saturated and unsaturated conditions. Water composition was monitored at high frequency (weekly) over a 3-year period for major anion composition and over a one year period for detailed 15N, CFC, SF6 and other dissolved gases. The results demonstrated that (i) the anionic composition in water table fluctuation zone varied significantly compared to deeper portions of the aquifer on the hillslope, confirming that this layer constitutes a main compartment for the mixing of new recharge water and old groundwater, (ii) seasonally, the variations of 15N and CFC are much higher during the recharge period than during the recession period, confirming the preferential flow during early recharge events, iii) variations of nitrate 15N and O18 composition was suggesting any significant denitrification process in the fluctuating zone, confirming the dominance of the mixing processes in the fluctuating zone, iv) deeper parts of the aquifer exhibited seasonal variations with structured hysteretic patterns, suggesting that mixing process also occurred at greater depths and v) these hysteretic patterns were dampered from upslope to downslope, indicating an increased influence of lateral flow downslope. A first modeling approach has been tested adding to a convection-dispersion model a mobile-immobile model, representing a mixing process between the pre-recharge water and the recharge water, and therefore taken into account the mixing processes varying from the surface to depth.As of now, we can deduce from these results that the residence times calculated from end member approaches considering the groundwater as homogeneous lumped reservoir are likely to be highly underestimated. We can also dedude that the water sampled in the shallow groundwater during the first part of the recharge period is chemically different from the water sampled after. Instrumented observatories including spatial and temporal monitoring of the hillslope groundwater are required to understand the anthropogenic and environmental processes and their interactions, to model and predict the effect and the response time of such systems under different constraints. This work is funded by AN-08-STRA-01 (National research Agency). Legout, C.; Molenat, J.; Aquilina, L.; Gascuel-Odoux, C.; Faucheux, M.; Fauvel, Y.; Bariac, T. 2007. Solute transfer in the unsaturated zone-groundwater continuum of a headwater catchment. Journal of Hydrology. 332 (2-4), 427-441. Rouxel, M., Molenat, J., Ruiz, L., Legout C., Faucheux, M., Gascuel-Odoux C., 2011. Seasonal and spatial variation in groundwater quality at the hillslope scale: study in an agricultural headwater catchment in Brittany (France). Hydrological Processes, 25, 831-841.

Timescales of mixing and storage for Keanakāko`i Tephra magmas (1500-1820 C.E.), Kīlauea Volcano, Hawai`i

NASA Astrophysics Data System (ADS)

Lynn, Kendra J.; Garcia, Michael O.; Shea, Thomas; Costa, Fidel; Swanson, Donald A.

2017-09-01

The last 2500 years of activity at Kīlauea Volcano (Hawai`i) have been characterized by centuries-long periods dominated by either effusive or explosive eruptions. The most recent period of explosive activity produced the Keanakāko`i Tephra (KT; ca. 1500-1820 C.E.) and occurred after the collapse of the summit caldera (1470-1510 C.E.). Previous studies suggest that KT magmas may have ascended rapidly to the surface, bypassing storage in crustal reservoirs. The storage conditions and rapid ascent hypothesis are tested here using chemical zoning in olivine crystals and thermodynamic modeling. Forsterite contents (Fo; [Mg/(Mg + Fe) × 100]) of olivine core and rim populations are used to identify melt components in Kīlauea's prehistoric (i.e., pre-1823) plumbing system. Primitive (≥Fo88) cores occur throughout the 300+ years of the KT period; they originated from mantle-derived magmas that were first mixed and stored in a deep crustal reservoir. Bimodal olivine populations (≥Fo88 and Fo83-84) record repeated mixing of primitive magmas and more differentiated reservoir components shallower in the system, producing a hybrid composition (Fo85-87). Phase equilibria modeling using MELTS shows that liquidus olivine is not stable at depths >17 km. Thus, calculated timescales likely record mixing and storage within the crust. Modeling of Fe-Mg and Ni zoning patterns (normal, reverse, complex) reveal that KT magmas were mixed and stored for a few weeks to several years before eruption, illustrating a more complex storage history than direct and rapid ascent from the mantle as previously inferred for KT magmas. Complexly zoned crystals also have smoothed compositional reversals in the outer 5-20 µm rims that are out of Fe-Mg equilibrium with surrounding glasses. Diffusion models suggest that these rims formed within a few hours to a few days, indicating that at least one additional, late-stage mixing event may have occurred shortly prior to eruption. Our study illustrates that the lifetimes of KT magmas are more complex than previously proposed, and that most KT magmas did not rise rapidly from the mantle without modification during shallow crustal storage.

Large eddy simulation of premixed and non-premixed combustion in a Stagnation Point Reverse Flow combustor

NASA Astrophysics Data System (ADS)

Undapalli, Satish

A new combustor referred to as Stagnation Point Reverse Flow (SPRF) combustor has been developed at Georgia Tech to meet the increasingly stringent emission regulations. The combustor incorporates a novel design to meet the conflicting requirements of low pollution and high stability in both premixed and non-premixed modes. The objective of this thesis work is to perform Large Eddy Simulations (LES) on this lab-scale combustor and elucidate the underlying physics that has resulted in its excellent performance. To achieve this, numerical simulations have been performed in both the premixed and non-premixed combustion modes, and velocity field, species field, entrainment characteristics, flame structure, emissions, and mixing characteristics have been analyzed. Simulations have been carried out first for a non-reactive case to resolve relevant fluid mechanics without heat release by the computational grid. The computed mean and RMS quantities in the non-reacting case compared well with the experimental data. Next, the simulations were extended for the premixed reactive case by employing different sub-grid scale combustion chemistry closures: Eddy Break Up (EBU), Artificially Thickened Flame (TF) and Linear Eddy Mixing (LEM) models. Results from the EBU and TF models exhibit reasonable agreement with the experimental velocity field. However, the computed thermal and species fields have noticeable discrepancies. Only LEM with LES (LEMLES), which is an advanced scalar approach, has been able to accurately predict both the velocity and species fields. Scalar mixing plays an important role in combustion, and this is solved directly at the sub-grid scales in LEM. As a result, LEM accurately predicts the scalar fields. Due to the two way coupling between the super-grid and sub-grid quantities, the velocity predictions also compare very well with the experiments. In other approaches, the sub-grid effects have been either modeled using conventional approaches (EBU) or need some ad hoc adjustments to account these effects accurately (TF). The results from LEMLES, using a reduced chemical mechanism, have been analyzed in the premixed mode. The results show that mass entrainment occurs along the shear layer in the combustor. The entrained mass carries products into the reactant stream and provides reactant preheating. Thus, product entrainment enhances the reaction rates and help stabilize the flame even at very lean conditions. These products have been shown to enter into the flame through local extinction zones present on the flame surface. The flame structure has been further analyzed, and the combustion mode was found to be primarily in thin reaction zones. Closer to the injector, there are isolated regions, where the combustion mode is in broken reaction zones, while the downstream flame structure is closer to a flamelet regime. The emissions in the combustor have been studied using simple global mechanisms for NO x. Computations have shown extremely low NOx values, comparable to the measured emissions. These low emissions have been shown to be primarily due to the low temperatures in the combustor. LEMLES computations have also been performed with a detailed chemistry to capture more accurate flame structure. The flame in the detailed chemistry case shows more extinction zones close to the injector than that in the reduced chemical mechanism. The LEMLES approach has also been used to resolve the combustion mode in the non-premixed case. The studies have indicated that the mixing of the fuel and air close to the injector controls the combustion process. The predictions in the near field have been shown to be very sensitive to the inflow conditions. Analysis has shown that the fuel and air mixing occurs to lean proportions in the combustor before any burning takes place. The flame structure in the non-premixed mode was very similar to the premixed mode. Along with the fuel air mixing, the products also mixed with the reactants and provided the preheating effects to stabilize the flame in the downstream region of the combustor.

MS-275 and Isotretinoin in Treating Patients With Metastatic or Advanced Solid Tumors or Lymphomas

ClinicalTrials.gov

2013-01-23

Adult Grade III Lymphomatoid Granulomatosis; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

The Li And Be Dips Revisited: The Role Of Gyroscopic Pumping.

NASA Astrophysics Data System (ADS)

Garaud, Pascale; Bodenheimer, P.

2011-01-01

The existence of a dip in the observed abundances of Li and Be in young stars in the mass range 1.3 to 1.5 solar masses strongly suggests the presence of an additional mixing mechanism to transport these elements from the outer convection zone down to the region where they are destroyed. However, no simple model to date has been able to reproduce simultaneously the respective amplitudes of the Li and the Be dips, as well as their shapes. We study here the effect of an important new mechanism for rotational mixing called "gyroscopic pumping", first noted for its importance in the dynamics of the solar interior, and find that it does indeed provide an elegant answer to this long-standing problem. Gyroscopic pumping is a simple and very generic consequence of angular momentum conservation in differentially rotating convective regions. The perpetual azimuthal force driving the differential rotation also drives a large-scale meridional circulation through angular momentum conservation. We show here how, specifically for the mass range of the Li-dip stars, the flows thus pumped form a slow, large-scale "conveyor belt" between the inner convective core and the outer convection zone. Li- and Be-rich material flowing down from the outer regions is slowly replaced by Li- and Be-poor material flowing up from the inner regions. Meanwhile, turbulent mixing in the thin overshoot layer also replenishes the outer convection zone with Li- and Be-rich material. Overall, the balance between advection by gyroscopic pumping and turbulent mixing by overshooting motions is found to provide a rather good agreement with observations of Li and Be, within a single and very simple framework. This work was funded by an NSF CAREER award of the presenting author.

Internal architecture, permeability structure, and hydrologic significance of contrasting fault-zone types

NASA Astrophysics Data System (ADS)

Rawling, Geoffrey C.; Goodwin, Laurel B.; Wilson, John L.

2001-01-01

The Sand Hill fault is a steeply dipping, large-displacement normal fault that cuts poorly lithified Tertiary sediments of the Albuquerque basin, New Mexico, United States. The fault zone does not contain macroscopic fractures; the basic structural element is the deformation band. The fault core is composed of foliated clay flanked by structurally and lithologically heterogeneous mixed zones, in turn flanked by damage zones. Structures present within these fault-zone architectural elements are different from those in brittle faults formed in lithified sedimentary and crystalline rocks that do contain fractures. These differences are reflected in the permeability structure of the Sand Hill fault. Equivalent permeability calculations indicate that large-displacement faults in poorly lithified sediments have little potential to act as vertical-flow conduits and have a much greater effect on horizontal flow than faults with fractures.

Magnetic ground state and magnon-phonon interaction in multiferroic h -YMnO3

NASA Astrophysics Data System (ADS)

Holm, S. L.; Kreisel, A.; Schäffer, T. K.; Bakke, A.; Bertelsen, M.; Hansen, U. B.; Retuerto, M.; Larsen, J.; Prabhakaran, D.; Deen, P. P.; Yamani, Z.; Birk, J. O.; Stuhr, U.; Niedermayer, Ch.; Fennell, A. L.; Andersen, B. M.; Lefmann, K.

2018-04-01

Inelastic neutron scattering has been used to study the magnetoelastic excitations in the multiferroic manganite hexagonal YMnO3. An avoided crossing is found between magnon and phonon modes close to the Brillouin zone boundary in the (a ,b ) plane. Neutron polarization analysis reveals that this mode has mixed magnon-phonon character. An external magnetic field along the c axis is observed to cause a linear field-induced splitting of one of the spin-wave branches. A theoretical description is performed, using a Heisenberg model of localized spins, acoustic phonon modes, and a magnetoelastic coupling via the single-ion magnetostriction. The model quantitatively reproduces the dispersion and intensities of all modes in the full Brillouin zone, describes the observed magnon-phonon hybridized modes, and quantifies the magnetoelastic coupling. The combined information, including the field-induced magnon splitting, allows us to exclude several of the earlier proposed models and point to the correct magnetic ground state symmetry, and provides an effective dynamic model relevant for the multiferroic hexagonal manganites.

Tower reactors for bioconversion of lignocellulosic material

DOEpatents

Nguyen, Q.A.

1998-03-31

An apparatus is disclosed for enzymatic hydrolysis and fermentation of pretreated lignocellulosic material. The apparatus consists of a tower bioreactor which has mixers to achieve intermittent mixing of the material. Precise mixing of the material is important for effective heat and mass transfer requirements without damaging or denaturing the enzymes or fermenting microorganisms. The pretreated material, generally in the form of a slurry, is pumped through the bioreactor, either upwards or downwards, and is mixed periodically as it passes through the mixing zones where the mixers are located. For a thin slurry, alternate mixing can be achieved by a pumping loop which also serves as a heat transfer device. Additional heat transfer takes place through the reactor heat transfer jackets. 5 figs.

Tower reactors for bioconversion of lignocellulosic material

DOEpatents

Nguyen, Q.A.

1999-03-30

An apparatus is described for enzymatic hydrolysis and fermentation of pretreated lignocellulosic material, in the form of a tower bioreactor, having mixers to achieve intermittent mixing of the material. Precise mixing of the material is important for effective heat and mass transfer requirements without damaging or denaturing the enzymes or fermenting microorganisms. The pretreated material, generally in the form of a slurry, is pumped through the bioreactor, either upwards or downwards, and is mixed periodically as it passes through the mixing zones where the mixers are located. For a thin slurry, alternate mixing can be achieved by a pumping loop which also serves as a heat transfer device. Additional heat transfer takes place through the reactor heat transfer jackets. 5 figs.

Aspects of Turbulent / Non-Turbulent Interfaces

NASA Technical Reports Server (NTRS)

Bisset, D. K.; Hunt, J. C. R.; Rogers, M. M.; Koen, Dennis (Technical Monitor)

1999-01-01

A distinct boundary between turbulent and non-turbulent regions in a fluid of otherwise constant properties is found in many laboratory and engineering turbulent flows, including jets, mixing layers, boundary layers and wakes. Generally, the flow has mean shear in at least one direction within t he turbulent zone, but the non-turbulent zones have no shear (adjacent laminar shear is a different case, e.g. transition in a boundary layer). There may be purely passive differences between the turbulent and non-turbulent zones, e.g. small variations in temperature or scalar concentration, for which turbulent mixing is an important issue. The boundary has several major characteristics of interest for the present study. Firstly, the boundary advances into the non-turbulent fluid, or in other words, nonturbulent fluid is entrained. Secondly, the change in turbulence properties across the boundary is remarkably abrupt; strong turbulent motions come close to the nonturbulent fluid, promoting entrainment. Thirdly, the boundary is irregular with a continually changing convoluted shape, which produces statistical intermittency. Its shape is contorted at all scales of the turbulent motion.

Green biosynthesis of magnetic iron oxide (Fe3O4) nanoparticles using the aqueous extracts of food processing wastes under photo-catalyzed condition and investigation of their antimicrobial and antioxidant activity.

PubMed

Patra, Jayanta Kumar; Baek, Kwang-Hyun

2017-08-01

In this study, a simple, rapid, and eco-friendly green method was introduced to synthesize magnetite iron oxide nanoparticles (Fe 3 O 4 NPs) using the aqueous extracts of two food processing wastes, namely silky hairs of corn (Zea mays L.) and outer leaves of Chinese cabbage (Brassica rapa L. subsp. pekinensis). The boiled solutions of silky hairs (MH) and outer leaves of Chinese cabbage (CCP) were used to synthesize Fe 3 O 4 NPs under photo exposed condition. The MH-FeNPs and CCP-FeNPs synthesized via green route were characterized by UV-Vis spectroscopy, field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential thermogravimetric (TG/DTG) analysis, and vibrating sample magnetometer (VSM) analysis. The UV-Visible spectra displayed two absorption bands at 325nm and 375mm for the MH-FeNPs, and 325mm and 365mm for the CCP-FeNPs, respectively. The estimated absolute crystallite sizes of the MH-FeNPs and CCP-FeNPs were calculated to be 84.81 and 48.91nm, respectively. VSM analysis revealed that both FeNPs were superparamagnetic in nature. Both FeNPs mixed with kanamycin and rifampicin displayed positive synergistic antibacterial activity against pathogenic foodborne bacteria (9.36-24.42mm inhibition zones), and those mixed with amphotericin b also exerted synergistic anticandidal activity against five different pathogenic Candida species (9.81-17.68mm inhibition zones). Both FeNPs exhibited strong antioxidant activities; therefore, all the properties of the green synthesized MH-FeNPs and CCP-FeNPs using food processing wastes could be beneficial for their potential applications in various fields such as drug delivery, antibacterial and anticandidal drugs, and biomedical fields. Copyright © 2017. Published by Elsevier B.V.

Geomorphic and hydraulic controls on large-scale riverbank failure on a mixed bedrock-alluvial river system, the River Murray, South Australia: a bathymetric analysis.

NASA Astrophysics Data System (ADS)

De Carli, E.; Hubble, T.

2014-12-01

During the peak of the Millennium Drought (1997-2010) pool-levels in the lower River Murray in South Australia dropped 1.5 metres below sea level, resulting in large-scale mass failure of the alluvial banks. The largest of these failures occurred without signs of prior instability at Long Island Marina whereby a 270 metre length of populated and vegetated riverbank collapsed in a series of rotational failures. Analysis of long-reach bathymetric surveys of the river channel revealed a strong relationship between geomorphic and hydraulic controls on channel width and downstream alluvial failure. As the entrenched channel planform meanders within and encroaches upon its bedrock valley confines the channel width is 'pinched' and decreases by up to half, resulting in a deepening thalweg and channel bed incision. The authors posit that flow and shear velocities increase at these geomorphically controlled 'pinch-points' resulting in complex and variable hydraulic patterns such as erosional scour eddies, which act to scour the toe of the slope over-steepening and destabilising the alluvial margins. Analysis of bathymetric datasets between 2009 and 2014 revealed signs of active incision and erosional scour of the channel bed. This is counter to conceptual models which deem the backwater zone of a river to be one of decelerating flow and thus sediment deposition. Complex and variable flow patterns have been observed in other mixed alluvial-bedrock river systems, and signs of active incision observed in the backwater zone of the Mississippi River, United States. The incision and widening of the lower Murray River suggests the channel is in an erosional phase of channel readjustment which has implications for riverbank collapse on the alluvial margins. The prevention of seawater ingress due to barrage construction at the Murray mouth and Southern Ocean confluence, allowed pool-levels to drop significantly during the Millennium Drought reducing lateral confining support to the over-steepened channel margins triggering large-scale riverbank failure.

Rituximab, Romidepsin, and Lenalidomide in Treating Patients With Recurrent or Refractory B-cell Non-Hodgkin Lymphoma

ClinicalTrials.gov

2016-08-09

B-cell Adult Acute Lymphoblastic Leukemia; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Testicular Lymphoma; Waldenström Macroglobulinemia

Formation of Intermediate Plutonic Rocks by Magma Mixing: the Shoshonite Suite of Timna, Southern Israel.

NASA Astrophysics Data System (ADS)

Fox, S.; Katzir, Y.

2017-12-01

In magmatic series considered to form by crystal fractionation intermediate rocks are usually much less abundant than expected. Yet, intermediate plutonic rocks, predominantly monzodiorites, are very abundant in the Neoproterozoic Timna igneous complex, S. Israel. A previously unnoticed plutonic shoshonitic suite was recently defined and mapped in Timna (Litvinovsky et al., 2015). It mostly comprises intermediate rocks in a seemingly 'continuous' trend from monzodiorite through monzonite to quartz syenite. Macroscale textures including gradational boundaries of mafic and felsic rocks and MME suggest that magma mixing is central in forming intermediate rocks in Timna. Our petrographic, microtextural and mineral chemistry study delineates the mode of incipient mixing, ultimate mingling and crystal equilibration in hybrid melts. An EMP study of plagioclase from rocks across the suite provides a quantitative evaluation of textures indicative of magma mixing/mingling, including recurrent/patchy zoning, Ca spike, boxy/sponge cellular texture and anti-Rapakivi texture. Each texture has an affinity to a particular mixing region. A modal count of these textures leads to a kinetic mixing model involving multi temporal and spatial scales necessary to form the hybrid intermediate rocks. A `shell'-like model for varying degrees of mixing is developed with the more intensive mixing at the core and more abundant felsic and mafic end-members towards the outer layer. REE patterns in zircon shows that it originated from both mafic and felsic parent melts. Whole rock Fe vs Sr plot suggests a two-stage mixing between the monzogabbro and quartz-syenite producing first mesocratic syenite, and subsequent mixing with a fractionating monzogabbro resulting in monzonitic compositions. A fractionating monzogabbro intruded into a syenitic melt sequentially. While slowly cooling, the monzogabbro heated the immediate syenitic melt, lowering the viscosity and rheological obstruction to overturn the boundary, and thus facilitated mixing. Increasing melt hybridization, tandem with crystallization, produced mixing textures in the turbulent crystal mush zone, synchronously with `pure end-member' crystallization. As a result, a large volume of intermediate rock was created through a hybridization process.

Gravity mode offset and properties of the evanescent zone in red-giant stars

NASA Astrophysics Data System (ADS)

Hekker, S.; Elsworth, Y.; Angelou, G. C.

2018-03-01

Context. The wealth of asteroseismic data for red-giant stars and the precision with which these data have been observed over the last decade calls for investigations to further understand the internal structures of these stars. Aim. The aim of this work is to validate a method to measure the underlying period spacing, coupling term, and mode offset of pure gravity modes that are present in the deep interiors of red-giant stars. We subsequently investigate the physical conditions of the evanescent zone between the gravity mode cavity and the pressure mode cavity. Methods: We implement an alternative mathematical description compared to what is used in the literature to analyse observational data and to extract the underlying physical parameters that determine the frequencies of mixed modes. This description takes the radial order of the modes explicitly into account, which reduces its sensitivity to aliases. Additionally, and for the first time, this method allows us to constrain the gravity mode offset ɛg for red-giant stars. Results: We find that this alternative mathematical description allows us to determine the period spacing ΔΠ and the coupling term q for the dipole modes within a few percent of values found in the literature. Additionally, we find that ɛg varies on a star-by-star basis and should not be kept fixed in the analysis. Furthermore, we find that the coupling factor is logarithmically related to the physical width of the evanescent region normalised by the radius at which the evanescent zone is located. Finally, the local density contrast at the edge of the core of red-giant branch models shows a tentative correlation with the offset ɛg. Conclusions: We are continuing to exploit the full potential of the mixed modes to investigate the internal structures of red-giant stars; in this case we focus on the evanescent zone. It remains, however, important to perform comparisons between observations and models with great care as the methods employed are sensitive to the range of input frequencies.

Universal microfluidic automaton for autonomous sample processing: application to the Mars Organic Analyzer.

PubMed

Kim, Jungkyu; Jensen, Erik C; Stockton, Amanda M; Mathies, Richard A

2013-08-20

A fully integrated multilayer microfluidic chemical analyzer for automated sample processing and labeling, as well as analysis using capillary zone electrophoresis is developed and characterized. Using lifting gate microfluidic control valve technology, a microfluidic automaton consisting of a two-dimensional microvalve cellular array is fabricated with soft lithography in a format that enables facile integration with a microfluidic capillary electrophoresis device. The programmable sample processor performs precise mixing, metering, and routing operations that can be combined to achieve automation of complex and diverse assay protocols. Sample labeling protocols for amino acid, aldehyde/ketone and carboxylic acid analysis are performed automatically followed by automated transfer and analysis by the integrated microfluidic capillary electrophoresis chip. Equivalent performance to off-chip sample processing is demonstrated for each compound class; the automated analysis resulted in a limit of detection of ~16 nM for amino acids. Our microfluidic automaton provides a fully automated, portable microfluidic analysis system capable of autonomous analysis of diverse compound classes in challenging environments.

Tests of two convection theories for red giant and red supergiant envelopes

NASA Technical Reports Server (NTRS)

Stothers, Richard B.; Chin, Chao-Wen

1995-01-01

Two theories of stellar envelope convection are considered here in the context of red giants and red supergiants of intermediate to high mass: Boehm-Vitense's standard mixing-length theory (MLT) and Canuto & Mazzitelli's new theory incorporating the full spectrum of turbulence (FST). Both theories assume incompressible convection. Two formulations of the convective mixing length are also evaluated: l proportional to the local pressure scale height (H(sub P)) and l proportional to the distance from the upper boundary of the convection zone (z). Applications to test both theories are made by calculating stellar evolutionary sequences into the red zone (z). Applications to test both theories are made by calculating stellar evolutionary sequences into the red phase of core helium burning. Since the theoretically predicted effective temperatures for cool stars are known to be sensitive to the assigned value of the mixing length, this quantity has been individually calibrated for each evolutionary sequence. The calibration is done in a composite Hertzsprung-Russell diagram for the red giant and red supergiant members of well-observed Galactic open clusters. The MLT model requires the constant of proportionality for the convective mixing length to vary by a small but statistically significant amount with stellar mass, whereas the FST model succeeds in all cases with the mixing lenghth simply set equal to z. The structure of the deep stellar interior, however, remains very nearly unaffected by the choices of convection theory and mixing lenghth. Inside the convective envelope itself, a density inversion always occurs, but is somewhat smaller for the convectively more efficient MLT model. On physical grounds the FST model is preferable, and seems to alleviate the problem of finding the proper mixing length.

Multi `omics reveals role of phenotypic plasticity in governing biogeochemical hotspots within the groundwater-surface water (hyporheic) mixing zone

NASA Astrophysics Data System (ADS)

Graham, E.; Tfaily, M. M.; Crump, A.; Arntzen, E.; Romero, E. B.; Goldman, A. E.; Resch, T.; Kennedy, D.; Nelson, W. C.; Stegen, J.

2017-12-01

Subsurface groundwater-surface water mixing zones (hyporheic zones) contain spatially heterogeneous hotspots of enhanced biogeochemical activity that contribute disproportionately to river corridor function. We have a poor understanding of the processes governing hotspots, but recent advances have enabled greater mechanistic understanding. We employ a suite of ultra-high resolution measurements to investigate the mechanisms underlying biogeochemical cycles in hyporheic zone hotspots. We use Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), metagenomic shotgun sequencing, and mass spectrometry of metaproteomes to characterize metabolite structure and metabolic transformations, microbiome structure and functional potential, and expressed microbiome functions in hyporheic sediments from the Columbia River in central Washington State. Surprisingly, microbiome structure and function in biogeochemical hotspots were indistinguishable from low-activity sediments. Metabolites were uncorrelated to protein expression but strongly related to aerobic respiration. Hotspot metabolites were distinguished by high molecular weight compounds and protein-, lignin-, and lipid-like molecules. Although the most common metabolic transformations were similar between hotspots and low-activity samples, hotspots contained a greater proportion of rare pathways, which in turn were correlated to metabolism. Our results contradicted our expectations that hotspots would be characterized by a unique microbiome with distinct physiology. Instead, our results indicate that microbial phenotypic plasticity underlies elevated hyporheic zone function, whereby the activity of rare pathways is stimulated by substrate availability. We therefore hypothesize that microbiome plasticity couples meso- (e.g., local root distribution) and macro-scale (e.g., landscape vegetation) resource heterogeneity to ecosystem-scale function. This indicates a need to mechanistically understand and represent microbiome physiological plasticity in predictive hydrobiogeochemical models that include the hyporheic zone.

Cortisol, Testosterone, and Prospective Risk for War-zone Stress-Evoked Depression.

PubMed

Cobb, Adam R; Josephs, Robert A; Lancaster, Cynthia L; Lee, Han-Joo; Telch, Michael J

2018-04-27

The major challenges of efforts to reveal biological risk factors and biomarkers of depression include the complexity of underlying systems, interactions with other systems, and contextual factors governing their expression. Altered endocrine function is believed to be a central contributor to depressive illness, but across studies, evidence for a link between endocrine markers and depression has been mixed, inconclusive, or conditional in nature. In the present study, we evaluated basal testosterone (T), cortisol (C), and CO2 inhalation-stress-reactivity measures of these hormones (TR, CR) as pre-deployment moderators of the later impact of war-zone stressors on depression symptoms in-theater. At pre-deployment, U.S. soldiers (N = 120) completed demographic, clinical and hormone measures, and during deployment, they completed monthly, web-based assessments of war-zone stressors and depression symptoms (N = 533 observations). Mixed effects models estimated the effects of the pre-deployment hormone profiles in moderating war-zone stressors' impact on in-theater depression. Models also tested whether hormonally linked risk for later stress-evoked depression depends on pre-existing depression. Controlling for pre-deployment depression, high T was protective; whereas TR had depressogenic effects that were amplified by pre-deployment depression. Further, high C was protective, but heightened CR was depressogenic, but only among those with elevated pre-deployment depression. Findings highlight the importance of examining basal and reactivity measures of endocrine function, and use of prospective, longitudinal models to test hypothesized causal pathways associated with depression vulnerability in the war-zone. Results also suggest that pre-existing depression and cortisol may work in tandem to increase vulnerability for later stress-evoked depression in the war-zone.

Coalbed methane accumulation and dissipation patterns: A Case study of the Junggar Basin, NW China

NASA Astrophysics Data System (ADS)

Li, Xin; Fu, Xuehai; Yang, Xuesong; Ge, Yanyan; Quan, Fangkai

2018-07-01

The Junggar Basin is a potential replacement area of coalbed methane (CBM) development in China. To improve the efficiency of CBM exploration, we investigated CBM accumulation and dissipation patterns of coal profiles located in the northwestern, southern, eastern, and central Junggar Basin based on the following criteria: burial depth, hydrogeological zone, CBM origin, CBM phase, and CBM migration type. We identified four types of CBM accumulation patterns: (1) a self-sourcing CBM pattern containing adsorbed gas of biogenic origin from shallow-depth coal within a weak runoff zone; (2) an endogenic migration pattern containing adsorbed gas of thermogenic origin from the medium and deep coals within a stagnant zone; (3) an exogenic migration pattern containing adsorbed gas of thermogenic origin from deep coal within a stagnant zone; and (4) an exogenic migration pattern containing adsorbed and free gas of thermogenic origin from ultra-deep coal within a stagnant zone. We also identified two types of CBM dissipation patterns: (1) shallow-depth coal within a runoff zone with mixed origin CBM; and (2) shallow and medium-deep coal seams with mixed origin CBM. CBM migration in low-rank coals was more substantial than that adsorbed in high-rank coal. CBM in shallow coal could easily escape, in the absence of closed structures or hydrogeological seals. CBM reservoirs occurred in deep coal where oversaturated gas may accumulate. Future exploration should focus on gas-water sealing structures in shallow coalbeds. CBM that occurred in adsorbed and free phases and other unconventional natural gas dominated by free gas in the coal stratum should be co-explored and co-developed.

Implementing the Aquidneck Island West Side Master Plan

EPA Pesticide Factsheets

This report describes a technical assistance project with Aquidneck Island to develop approaches for mixed-use zoning standards, design guidelines, and review processes to implement the West Side Master Plan.

Magma Mixing, Mingling and Its Accompanying Isotopic and Elemental Partitioning: Records from Titanites in Guojialing-type Granodiorites and Dioritic Enclaves, Jiaodong, North China

NASA Astrophysics Data System (ADS)

Jiang, P.; Yang, K. F.; Fan, H. R.; Liu, X.

2016-12-01

The grain-scale textural and in-situ compositional analyses on accessory minerals (such as titanite, rutile, apatite, monazite, etc.) have recently been a hot topic for geologists, through which a detailed information on magmatic, metamorphic or hydrothermal process can be extracted. As an attempt to unravel the petrogenesis of Early Cretaceous Guojialing-type granodiorites and their bearing dioritic enclaves, we accomplished an integrated geochronological and geochemical study on titanites within these rocks. Three types of titanites, with distinguishable textural and geochemical features, are identified. G-type titanites (from granodiorites) and E-type-I titanites (from plagioclase-rich dioritic enclaves) yield identical U-Pb age of 130 Ma, but reveal distinct back-scattered electron (BSE) zonings. G-type titanites are characterized by oscillatory zonings whereas E-type-I titanites are marked by core-mantle-rim zonings, exhibiting drastic but contrary variation trends for several key elements (such as LREEs, Zr, Hf and F) among their transition BSE zones. These two types of titanites are interpreted to crystallize coevally, and record a notable temperature and compositional change of two corresponding melts, as a response to magma mixing. E-type-II titanites (from plagioclase-poor dioritic enclaves) yield a relatively younger U-Pb age at 128 Ma, and show typical interstitial growth with narrower and lower range of Zr, total REEs contents, but higher F content and Nb/Ta ratios. Such titanites are perceived to record late-stage mingling, during which F-rich and REE-poor hybrid granodioritic magma squeezed into the incompletely consolidated dioritic enclaves with accompanying fluid-rock interaction. Unlike the dramatic elemental changes in these differentiated titanites, in-situ Nd isotopic compositions are relatively homogeneous, which in our view is a good sign of showing that isotopic equilibrium among two magma systems was more easily reached compared to elemental homogenization during the process of magma mixing and mingling. Our titanite work provides new and solid evidence to support a magma mixing genesis for Guojialing intrusion, and also presents a good case study of utilizing accessory titanite to decipher a detailed magmatic chamber process.

Mighty Microbes Where Rivers Run

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stegen, James

2016-04-07

Microbes and their influential role in Earth’s climate take center stage in the area where river water and groundwater mix – an area known as the hyporheic zone. PNNL ecologist James Stegen discusses his team’s research in his “laboratory” – the zone along the Columbia, one of the nation’s largest rivers. It’s a squishy, porous lab, better known for soaking feet than serving as the “river’s liver.”

Analysis of the geochemical gradient created by surface-groundwater interactions within riverbanks of the East River in Crested Butte, Colorado

NASA Astrophysics Data System (ADS)

Lunzer, J.; Williams, K. H.; Malenda, H. F.; Nararne-Sitchler, A.

2016-12-01

An improved understanding of the geochemical gradient created by the mixing of surface and groundwater of a river system will have considerable impact on our understanding of microorganisms, organic cycling and biogeochemical processes within these zones. In this study, the geochemical gradient in the hyporheic zone is described using a variety of geochemical properties. A system of shallow groundwater wells were installed in a series of transects along a stream bank. Each transect consists of several wells that progress away from the river bank in a perpendicular fashion. From these wells, temperature, conductivity and pH of water samples were obtained via hand pumping or bailing. These data show a clear geochemical gradient that displays a distinct zone in the subsurface where the geochemical conditions change from surface water dominated to groundwater dominated. For this study, the East River near Crested Butte, Colorado has been selected as the river of interest due the river being a relatively undisturbed floodplain. Additionally, the specific section chosen on the East River displays relatively high sinuosity meaning that these meandering sections will produce hyporheic zones that are more laterally expansive than what would be expected on a river of lower sinuosity. This increase in lateral extension of the hyporheic zone will make depicting the subtle changes in the geochemical gradient much easier than that of a river system in which the hyporheic zone is not as laterally extensive. Data has been and will be continued to be collected at different river discharges to evaluate the geochemical gradient at differing rates. Overall, this characterization of the geochemical gradient along stream banks will produce results that will aid in the further use of geochemical methods to classify and understand hyporheic exchange zones and the potential expansion of these techniques to river systems of differing geologic and geographic conditions.

Under-Ice Phytoplankton Blooms Inhibited by Spring Convective Mixing in Refreezing Leads

NASA Astrophysics Data System (ADS)

Lowry, Kate E.; Pickart, Robert S.; Selz, Virginia; Mills, Matthew M.; Pacini, Astrid; Lewis, Kate M.; Joy-Warren, Hannah L.; Nobre, Carolina; van Dijken, Gert L.; Grondin, Pierre-Luc; Ferland, Joannie; Arrigo, Kevin R.

2018-01-01

Spring phytoplankton growth in polar marine ecosystems is limited by light availability beneath ice-covered waters, particularly early in the season prior to snowmelt and melt pond formation. Leads of open water increase light transmission to the ice-covered ocean and are sites of air-sea exchange. We explore the role of leads in controlling phytoplankton bloom dynamics within the sea ice zone of the Arctic Ocean. Data are presented from spring measurements in the Chukchi Sea during the Study of Under-ice Blooms In the Chukchi Ecosystem (SUBICE) program in May and June 2014. We observed that fully consolidated sea ice supported modest under-ice blooms, while waters beneath sea ice with leads had significantly lower phytoplankton biomass, despite high nutrient availability. Through an analysis of hydrographic and biological properties, we attribute this counterintuitive finding to springtime convective mixing in refreezing leads of open water. Our results demonstrate that waters beneath loosely consolidated sea ice (84-95% ice concentration) had weak stratification and were frequently mixed below the critical depth (the depth at which depth-integrated production balances depth-integrated respiration). These findings are supported by theoretical model calculations of under-ice light, primary production, and critical depth at varied lead fractions. The model demonstrates that under-ice blooms can form even beneath snow-covered sea ice in the absence of mixing but not in more deeply mixed waters beneath sea ice with refreezing leads. Future estimates of primary production should account for these phytoplankton dynamics in ice-covered waters.

Combustor with two stage primary fuel tube with concentric members and flow regulating

DOEpatents

Parker, David Marchant; Whidden, Graydon Lane; Zolyomi, Wendel

1999-01-01

A combustor for a gas turbine having a centrally located fuel nozzle and inner, middle and outer concentric cylindrical liners, the inner liner enclosing a primary combustion zone. The combustor has an air inlet that forms two passages for pre-mixing primary fuel and air to be supplied to the primary combustion zone. Each of the pre-mixing passages has a circumferential array of swirl vanes. A plurality of primary fuel tube assemblies extend through both pre-mixing passages, with each primary fuel tube assembly located between a pair of swirl vanes. Each primary fuel tube assembly is comprised of two tubular members. The first member supplies fuel to the first pre-mixing passage, while the second member, which extends through the first member, supplies fuel to the second pre-mixing passage. An annular fuel manifold is divided into first and second chambers by a circumferentially extending baffle. The proximal end of the first member is attached to the manifold itself while the proximal end of the second member is attached to the baffle. The distal end of the first member is attached directly to the second member at around its mid-point. The inlets of the first and second members are in flow communication with the first and second manifold chambers, respectively. Control valves separately regulate the flow of fuel to the two chambers and, therefore, to the two members of the fuel tube assemblies, thereby allowing the flow of fuel to the first and second pre-mixing passages to be separately controlled.

Experimental study on effects of geologic heterogeneity in enhancing dissolution trapping of supercritical CO2

NASA Astrophysics Data System (ADS)

Agartan, Elif; Trevisan, Luca; Cihan, Abdullah; Birkholzer, Jens; Zhou, Quanlin; Illangasekare, Tissa H.

2015-03-01

Dissolution trapping is one of the primary mechanisms that enhance the storage security of supercritical carbon dioxide (scCO2) in saline geologic formations. When scCO2 dissolves in formation brine produces an aqueous solution that is denser than formation brine, which leads to convective mixing driven by gravitational instabilities. Convective mixing can enhance the dissolution of CO2 and thus it can contribute to stable trapping of dissolved CO2. However, in the presence of geologic heterogeneities, diffusive mixing may also contribute to dissolution trapping. The effects of heterogeneity on mixing and its contribution to stable trapping are not well understood. The goal of this experimental study is to investigate the effects of geologic heterogeneity on mixing and stable trapping of dissolved CO2. Homogeneous and heterogeneous media experiments were conducted in a two-dimensional test tank with various packing configurations using surrogates for scCO2 (water) and brine (propylene glycol) under ambient pressure and temperature conditions. The results show that the density-driven flow in heterogeneous formations may not always cause significant convective mixing especially in layered systems containing low-permeability zones. In homogeneous formations, density-driven fingering enhances both storage in the deeper parts of the formation and contact between the host rock and dissolved CO2 for the potential mineralization. On the other hand, for layered systems, dissolved CO2 becomes immobilized in low-permeability zones with low-diffusion rates, which reduces the risk of leakage through any fault or fracture. Both cases contribute to the permanence of the dissolved plume in the formation.

Shallow Water UXO Technology Demonstration Site Scoring Record No. 6

DTIC Science & Technology

2007-03-01

ferrous, nonferrous , and mixed metals . The ferrous and nonferrous items have been further divided into three weight zones as presented in Table 1...items are present as well. The mixed- metals clutter is composed of scrap ordnance items or fragments that have both a ferrous and nonferrous ...underwater system using Geonics EM61 High Power (underwater coils) electromagnetic metal detectors (one transmitter coil, three receiver coils). The

Dolomitization of Quaternary reef limestones, Aitutaki, Cook Islands

USGS Publications Warehouse

Hein, J.R.; Gray, S.C.; Richmond, B.M.; White, L.D.

1992-01-01

The primary reef framework is considered to have been deposited during several highstands of sea level. Following partial to local recrystallization of the limestone, a signle episode of dolomitization occurred. Both tidal and thermal pumping drove large quantities of seawater through the porous rocks and perhaps maintained a wide mixing zone. However, the isotopic, geochemical and petrographic data do not clearly indicate the extent of seawater mixing. -from Authors

Cooling of a Magmatic System Under Thermal Chaotic Mixing

NASA Astrophysics Data System (ADS)

El Omari, Kamal; Le Guer, Yves; Perugini, Diego; Petrelli, Maurizio

2015-07-01

The cooling of a basaltic melt undergoing chaotic advection is studied numerically for a magma with a temperature-dependent viscosity in a two-dimensional (2D) cavity with moving boundary. Different statistical mixing and energy indicators are used to characterize the efficiency of cooling by thermal chaotic mixing. We show that different cooling rates can be obtained during the thermal mixing of a single basaltic magmatic batch undergoing chaotic advection. This process can induce complex temperature patterns inside the magma chamber. The emergence of chaotic dynamics strongly modulates the temperature fields over time and greatly increases the cooling rates. This mechanism has implications for the thermal lifetime of the magmatic body and may favor the appearance of chemical heterogeneities in the igneous system as a result of different crystallization rates. Results from this study also highlight that even a single magma batch can develop, under chaotic thermal advection, complex thermal and therefore compositional patterns resulting from different cooling rates, which can account for some natural features that, to date, have received unsatisfactory explanations, including the production of magmatic enclaves showing completely different cooling histories compared with the host magma, compositional zoning in mineral phases, and the generation of large-scale compositional zoning observed in many plutons worldwide.

Effect of Jet Injection Angle and Number of Jets on Mixing and Emissions From a Reacting Crossflow at Atmospheric Pressure

NASA Technical Reports Server (NTRS)

St.John, D.; Samuelsen, G. S.

2000-01-01

The mixing of air jets into hot, fuel-rich products of a gas turbine primary zone is an important step in staged combustion. Often referred to as "quick quench," the mixing occurs with chemical conversion and substantial heat release. An experiment has been designed to simulate and study this process, and the effect of varying the entry angle (0 deg, 22.5 deg and 45 deg from normal) and number of the air jets (7, 9, and 11) into the main flow, while holding the jet-to-crossflow mass-low ratio, MR, and momentum-flux ratio, J, constant (MR = 2.5;J = 25). The geometry is a crossflow confined in a cylindrical duct with side-wall injection of jets issuing from orifices equally spaced around the perimeter. A specially designed reactor, operating on propane, presents a uniform mixture to a module containing air jet injection tubes that can be changed to vary orifice geometry. Species concentrations of O2, CO, CO2, NO(x) and HC were obtained one duct diameter upstream (in the rich zone), and primarily one duct radius downstream. From this information, penetration of the jet, the spatial extent of chemical reaction, mixing, and the optimum jet injection angle and number of jets can be deduced.

Dynamics and fates of trace metals chronically input in a Mediterranean coastal zone impacted by a large urban area.

PubMed

Oursel, B; Garnier, C; Durrieu, G; Mounier, S; Omanović, D; Lucas, Y

2013-04-15

Quantification and characterization of chronic inputs of trace metals and organic carbon in a coastal Mediterranean area (the city of Marseille) during the dry season was carried out. The 625 km(2) watershed includes two small coastal rivers whose waters are mixed with treated wastewater (TWW) just before their outlet into the sea. Dissolved and particulate Cu, Pb, Cd, Zn, Co, Ni and organic carbon concentrations in the rivers were comparable to those in other Mediterranean coastal areas, whereas at the outlet, 2- to 18-fold higher concentrations reflected the impact of the TWW. A non-conservative behavior observed for most of the studied metals in the mixing zone was validated by a remobilization experiment performed in the laboratory. The results showed that sorption/desorption processes could occur with slow kinetics with respect to the mixing time in the plume, indicating non-equilibrium in the dissolved/particulate metal distribution. Thus, a sample filtration immediately after sampling is strictly required. Copyright © 2013 Elsevier Ltd. All rights reserved.

System and method for generating 3D images of non-linear properties of rock formation using surface seismic or surface to borehole seismic or both

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vu, Cung Khac; Nihei, Kurt Toshimi; Johnson, Paul A.

A system and method of characterizing properties of a medium from a non-linear interaction are include generating, by first and second acoustic sources disposed on a surface of the medium on a first line, first and second acoustic waves. The first and second acoustic sources are controllable such that trajectories of the first and second acoustic waves intersect in a mixing zone within the medium. The method further includes receiving, by a receiver positioned in a plane containing the first and second acoustic sources, a third acoustic wave generated by a non-linear mixing process from the first and second acousticmore » waves in the mixing zone; and creating a first two-dimensional image of non-linear properties or a first ratio of compressional velocity and shear velocity, or both, of the medium in a first plane generally perpendicular to the surface and containing the first line, based on the received third acoustic wave.« less

Applications of electrical resistivity imaging for characterizing groundwater-surface water interactions from local to regional scales

NASA Astrophysics Data System (ADS)

Cardenas, M. B.; Befus, K. M.; Zamora, P. B.; Ong, J.; Zlotnik, V. A.; Cook, P. L.; Tait, D. R.; Erler, D.; Santos, I. R.; Siringan, F. P.

2012-12-01

Surface water (SW) and groundwater (GW) interact across multiple spatial and temporal scales and their interaction is important for ecological and biogeochemical functions. The mixing of GW and SW has been challenging to simultaneously map with sufficient detail and coverage. Fortunately, ambient differences in salinity of waters occupying geologic formations and sediment are an ideal target for electrical resistivity imaging (ERI). We present examples of the application of ERI for mapping GW discharge and for understanding GW-SW interactions at: (1) a large regulated river, (2) neighboring lakes with differing salinity, (3) fringing coral reefs and lagoons, (4) beaches, and (5) estuaries. In all these cases, the ER tomograms were critical for improving conceptual understanding of GW-SW interactions. At the Lower Colorado River in Austin, Texas (USA), time-lapse ERI was conducted across a 12-hour dam-release cycle when the river stage varied by 0.7 m. Using temporal variability in electrical resistivity (ER) signatures, we identified a shallow well-flushed hyporheic zone, a transition zone where SW and GW mix, and a stable deep zone hosting only GW. In alkaline lakes in the Nebraska Sand Hills (Nebraska, USA), ER surveys using boat-towed cables allowed for mapping the 3D electrical structure underneath the lake. The tomograms were used to distinguish flow-through lakes, which have decreasing subsurface ER from GW inflow to outflow area, from pure GW discharge lakes, which have uniformly stratified increasing-with-depth ER profiles. Moreover, GW plumes in both discharge and recharge zones were clearly outlined underneath the lake. More than 30 km of ER profiles collected via boat-towed surveys over a fringing coral reef in the Philippines identified areas of high ER within the reef that coincide with resistive zones in the seawater. Analysis of 222Rn of bottom waters and vertical conductivity-temperature-depth measurements show the persistence of fresh GW input into the ocean where low salinity and high 222Rn areas coincided with high ER areas. In Muri Lagoon in Rarotonga Island of the Cook Islands, boat-towed ER surveys similarly showed areas underneath the lagoon that have groundwater that is fresher than seawater. Likewise, there was 222Rn high concentrations throughout the lagoon. Closer to shore, ER surveys using fixed electrodes showed complex 3D mixing processes between seawater and terrestrial-sourced fresh groundwater in beach sediment. Lastly, both boat-towed and fixed surveys across the salt wedge of Werribee Estuary west of Melbourne, Australia, outlined the estuarine salt wedge and its relationship with and effect on fresh and nutrient-laden groundwater discharging to the estuary. The examples discussed illustrate that ERI is a powerful and convenient tool for mapping GW discharge and GW-SW interactions across different scales and diverse environments.

Multiple Sulfate Isotopic Evidence on the Formation of Oxide Copper Ore at Spence, Atacama Desert, Northern Chile

NASA Astrophysics Data System (ADS)

Sun, T.; Bao, H.; Reich, M.; Palacios, C.

2007-12-01

In the Atacama Desert of northern Chile, one of the world's richest metallogenic provinces, porphyry copper deposits are characterized by the unique occurrence of atacamite in their oxidized zones. The origin and formation of the oxide zone of these copper deposits is, however, controversial. It was proposed that Cl-rich deep formation water pumping-up events along faults by earthquakes, after onset of the hyperaridity, were required (Cameron et al., 2007). Their model would imply that supplies of saline deep formation water from fractures to the surface should have left behind a homogeneous or fracture-controlled salt profile from surface down to the oxide zone. While no excluding the deep formation water model in other deposit, here we propose that, in our sampling region, the alternative saline source, which is critical for atacamite formation, could be locally evaporated groundwater, Cl-rich salts leached from arid surface by meteoric water, or brines from eastern salar basins at a time when the climate in northern Chile was changing from arid to hyperarid. At this climate transition, arid- requiring minerals such as atacamite in the oxide zone were formed and, more importantly, preserved upon evaporation beneath the surface alluvial deposits. Since salt accumulation at the surface remain active during hyperarid condition, our model would predict that water-soluble salt profile from surface to the oxide zone should have a characteristic pattern: salts with an atmospheric component on the surface gradually transitioning to salts of the oxide ore zone on the bottom and a mixing zone in between. To test these two alternative models, we focus on sulfate salts, one of the common water-soluble salts in arid environments. An added advantage is that sulfate accumulated on desert surface has a secondary atmospheric component that bears a unique triple oxygen isotope signature, easily distinguishable from sulfate formed by the oxidation of sulfide minerals at the oxide ore zone. Samples were collected from a drill core that extends from surface soil to an oxide zone where gypsum and jarosite coexist with atacamite at Spence, a supergene enriched copper porphyry deposit located between Calama and Antofagasta. We found that at 15 to ~100 m depths, the Δ17O and δ34S both decrease while the δ18O increases steadily with depths, suggesting a binary mixing of two distinct sulfate sources, with the surface sulfate having Δ17O, δ34S, and δ18O at +0.55‰, +5.80‰, and +10.80‰, while the deep oxide-ore- zone sulfate at -0.23‰, +3.6‰, and+19.8‰, respectively. The surface sulfate has reached a maximum depth of ~ 50 meters, as marked by the disappearance of positive Δ17O signals at that depth. The intact preservation of this transitional sulfate mixing profile supports our model, a model that does not require a deep formation water source for atacamite formation in oxide zone of Spence copper porphyry deposit.

How does conversion from peat swamp forest to oil palm plantation affect emissions of nitrous oxide from the soil? A case study in Jambi, Indonesia

NASA Astrophysics Data System (ADS)

Hartill, Jodie; Hergoualc'h, Kristell; Comeau, Louis-Pierre; Jo, Smith; Lou, Verchot

2017-04-01

Half of the peatlands across Peninsular Malaysia, Borneo and Sumatra are 'managed'. Conversion of peat swamp forest to workable oil palm plantation requires a drastic, potentially irreversible, change to the landscape, to which fertilizers are then routinely applied. A combination of these factors is now widely thought to increase soil nitrous oxide (N2O) emissions, although there is high uncertainty due to gaps in the knowledge, both regionally and nationally. Despite the widespread use of fertilizers in plantations on peats, studies observing their effects remain very limited. Therefore, there is a need for in situ studies to evaluate how environmental parameters (edaphic properties, climate, soil moisture and N availability indicators) influence soil emissions. This 18 month study was located in plots local to each other, representing the start, intermediate and end of the land conversion process; namely mixed peat swamp forest, drained and logged forest and industrial oil palm plantation. Spatial variability was taken into account by differentiating the hollows and hummocks in the mixed peat swamp forest, and the fertilized zone and the zone without fertilizer addition in the oil palm plantation. Gas samples were collected each month from static chambers at the same time as key environmental parameters were measured. Intensive sampling was performed during a 35 day period following two fertilizer applications, in which urea was applied to palms at rates of 0.5 and 1 kg urea palm-1. Soil N2O emissions (kg N ha-1 y-1 ± SE) were low overall, but they were greater in the oil palm plantation (0.8 ± 0.1) than in the mixed peat swamp forest (0.3 ± 0.0) and the drained/logged forest (0.2 ± 0.0). In the mixed peat swamp forest, monthly average fluxes of N2O (g N ha-1 d-1 ± SE) were similar in the hollows (0.6 ± 0.2) and the hummocks (0.3 ± 0.1), whereas in the oil palm plantation they were consistently higher in the zone without fertilizer (2.5 ± 0.4) than in the fertilized zone (0.5 ± 0.1), even after fertilizer application. In the fertilized zones, the N2O fluxes following the two fertilizer applications were 2.4 and 4.5 times higher respectively than fluxes observed in the absence of fertilizers. No change in emissions was observed in the neighboring unfertilized zone at the time of fertilizer application. Soil N2O emissions were related to changes in air and soil temperature in the mixed peat swamp forest, air temperature and water table depth in the drained and logged forest, and rainfall on the day of measurement in the oil palm plantation. This research confirms that peat forest conversion to oil palm plantation has negative consequences on the emissions of N2O. It also corroborates an increase in emission due to fertilizer application, with a magnitude comparable to the emission factor provided by the IPCC guidelines, but this is restricted to the limited area of fertilizer application.

Role of medium heterogeneity and viscosity contrast in miscible flow regimes and mixing zone growth: A computational pore-scale approach

NASA Astrophysics Data System (ADS)

Afshari, Saied; Hejazi, S. Hossein; Kantzas, Apostolos

2018-05-01

Miscible displacement of fluids in porous media is often characterized by the scaling of the mixing zone length with displacement time. Depending on the viscosity contrast of fluids, the scaling law varies between the square root relationship, a sign for dispersive transport regime during stable displacement, and the linear relationship, which represents the viscous fingering regime during an unstable displacement. The presence of heterogeneities in a porous medium significantly affects the scaling behavior of the mixing length as it interacts with the viscosity contrast to control the mixing of fluids in the pore space. In this study, the dynamics of the flow and transport during both unit and adverse viscosity ratio miscible displacements are investigated in heterogeneous packings of circular grains using pore-scale numerical simulations. The pore-scale heterogeneity level is characterized by the variations of the grain diameter and velocity field. The growth of mixing length is employed to identify the nature of the miscible transport regime at different viscosity ratios and heterogeneity levels. It is shown that as the viscosity ratio increases to higher adverse values, the scaling law of mixing length gradually shifts from dispersive to fingering nature up to a certain viscosity ratio and remains almost the same afterwards. In heterogeneous media, the mixing length scaling law is observed to be generally governed by the variations of the velocity field rather than the grain size. Furthermore, the normalization of mixing length temporal plots with respect to the governing parameters of viscosity ratio, heterogeneity, medium length, and medium aspect ratio is performed. The results indicate that mixing length scales exponentially with log-viscosity ratio and grain size standard deviation while the impact of aspect ratio is insignificant. For stable flows, mixing length scales with the square root of medium length, whereas it changes linearly with length during unstable flows. This scaling procedure allows us to describe the temporal variation of mixing length using a generalized curve for various combinations of the flow conditions and porous medium properties.

Variability in pigment concentration in warm-core rings as determined by coastal zone color scanner satellite imagery from the Mid-Atlantic Bight

NASA Technical Reports Server (NTRS)

Garcia-Moliner, Graciela; Yoder, James A.

1994-01-01

A time series of coastal zone color scanner (CZCS) derived chlorophyll (CZCS-chl) and sea surface temperature (SST) satellite imagery was developed for the Mid-Atlantic Bight (MAB). Warm-core rings (WCR) were identified by both the warmer SST signal as well as the low pigment concentrations of their cores. The variation in pigment concentrations and SST observed in satellite imagery over the geographic range and life span of four WCRs is investigated. The hypotheses are that pigment concentration increase during the lifetime of the WCR is a response to processes such as convective overturn, upwelling, edge enhancement due to increased vertical mixing, active convergence, or lateral exchange. Empirical orthogonal function analysis (EOF) is used to investigate the relationship between SST and pigment patterns observed in the presence of a WCR. The first two EOF modes explain more than 80% of the variability observed in all four WCRs and in both (SST and pigment) data sets. The results of this study show that, at the synoptic scales of staellite data, the variability observed in the WCRs is greater at the periphery of the rings. These results show that advective entrainment, rather than processes at ring center (e.g., shoaling of the pycnocline/nutricline in response to frictional decay) or at the periphery due to other processes such as vertical mixing, is the mechanism responsible for the observed variability.

Biomass characteristics of two types of submerged membrane bioreactors for nitrogen removal from wastewater.

PubMed

Liang, Zhihua; Das, Atreyee; Beerman, Daniel; Hu, Zhiqiang

2010-06-01

Biomass characteristics and microbial community diversity between a submerged membrane bioreactor with mixed liquor recirculation (MLE/MBR) and a membrane bioreactor with the addition of integrated fixed biofilm medium (IFMBR) were compared for organic carbon and nitrogen removal from wastewater. The two bench-scale MBRs were continuously operated in parallel at a hydraulic retention time (HRT) of 24h and solids retention time (SRT) of 20d. Both MBRs demonstrated good COD removal efficiencies (>97.7%) at incremental inflow organic loading rates. The total nitrogen removal efficiencies were 67% for MLE/MBR and 41% for IFMBR. The recirculation of mixed liquor from aerobic zone to anoxic zone in the MLE/MBR resulted in higher microbial activities of heterotrophic (46.96mgO(2)/gVSSh) and autotrophic bacteria (30.37mgO(2)/gVSSh) in the MLE/MBR compared to those from IFMBR. Terminal Restriction Fragment Length Polymorphism analysis indicated that the higher nitrifying activities were correlated with more diversity of nitrifying bacterial populations in the MLE/MBR. Membrane fouling due to bacterial growth was evident in both the reactors. Even though the trans-membrane pressure and flux profiles of MLE/MBR and IFMBR were different, the patterns of total membrane resistance changes had no considerable difference under the same operating conditions. The results suggest that metabolic selection via alternating anoxic/aerobic processes has the potential of having higher bacterial activities and improved nutrient removal in MBR systems. Copyright 2010 Elsevier Ltd. All rights reserved.

Stable isotope analysis of vertebrae reveals ontogenetic changes in habitat in an endothermic pelagic shark

PubMed Central

Carlisle, Aaron B.; Goldman, Kenneth J.; Litvin, Steven Y.; Madigan, Daniel J.; Bigman, Jennifer S.; Swithenbank, Alan M.; Kline, Thomas C.; Block, Barbara A.

2015-01-01

Ontogenetic changes in habitat are driven by shifting life-history requirements and play an important role in population dynamics. However, large portions of the life history of many pelagic species are still poorly understood or unknown. We used a novel combination of stable isotope analysis of vertebral annuli, Bayesian mixing models, isoscapes and electronic tag data to reconstruct ontogenetic patterns of habitat and resource use in a pelagic apex predator, the salmon shark (Lamna ditropis). Results identified the North Pacific Transition Zone as the major nursery area for salmon sharks and revealed an ontogenetic shift around the age of maturity from oceanic to increased use of neritic habitats. The nursery habitat may reflect trade-offs between prey availability, predation pressure and thermal constraints on juvenile endothermic sharks. The ontogenetic shift in habitat coincided with a reduction of isotopic niche, possibly reflecting specialization upon particular prey or habitats. Using tagging data to inform Bayesian isotopic mixing models revealed that adult sharks primarily use neritic habitats of Alaska yet receive a trophic subsidy from oceanic habitats. Integrating the multiple methods used here provides a powerful approach to retrospectively study the ecology and life history of migratory species throughout their ontogeny. PMID:25621332

The crustal magma storage system of Volcán Quizapu, Chile, and the effects of magma mixing on magma diversity

USGS Publications Warehouse

Bergantz, George W.; Cooper, Kari M.; Hildreth, Edward; Ruprecht, Phillipp

2012-01-01

Crystal zoning as well as temperature and pressure estimates from phenocryst phase equilibria are used to constrain the architecture of the intermediate-sized magmatic system (some tens of km3) of Volcán Quizapu, Chile, and to document the textural and compositional effects of magma mixing. In contrast to most arc magma systems, where multiple episodes of open-system behavior obscure the evidence of major magma chamber events (e.g. melt extraction, magma mixing), the Quizapu magma system shows limited petrographic complexity in two large historical eruptions (1846–1847 and 1932) that have contrasting eruptive styles. Quizapu magmas and peripheral mafic magmas exhibit a simple binary mixing relationship. At the mafic end, basaltic andesite to andesite recharge magmas complement the record from peripheral cones and show the same limited range of compositions. The silicic end-member composition is almost identical in both eruptions of Quizapu. The effusive 1846–1847 eruption records significant mixing between the mafic and silicic end-members, resulting in hybridized andesites and mingled dacites. These two compositionally simple eruptions at Volcán Quizapu present a rare opportunity to isolate particular aspects of magma evolution—formation of homogeneous dacite magma and late-stage magma mixing—from other magma chamber processes. Crystal zoning, trace element compositions, and crystal-size distributions provide evidence for spatial separation of the mafic and silicic magmas. Dacite-derived plagioclase phenocrysts (i.e. An25–40) show a narrow range in composition and limited zonation, suggesting growth from a compositionally restricted melt. Dacite-derived amphibole phenocrysts show similar restricted compositions and furthermore constrain, together with more mafic amphibole phenocrysts, the architecture of the magmatic system at Volcán Quizapu to be compositionally and thermally zoned, in which an andesitic mush is overlain by a homogeneous dacitic magma that is the source for most of the 1846–1847 and 1932 erupted magmas. Dacite formation is best explained by mineral–melt separation (crystal fractionation) from an andesitic mush, which is inferred to have thermally and compositionally buffered the dacite magma thereby keeping it at relatively low crystallinity (<30 vol. %). The dominant cause of compositional diversity is melt separation. Back-mixing of mush (i.e. crystals with signatures of growth both in the andesitic mush and in the dacite magma) into the overlying dacite magma is rarely observed. Recharge events that increase crystal and magma diversity in the dacite magma are limited to an episode of mafic recharge and mixing just prior to the 1846–1847 eruption, where evidence for magma mixing is present on all scales. Chamber-wide mixing was incomplete (mixing efficiency of ∼0·53–0·85) as flow lobes vary significantly in composition along the proposed mixing array. Estimates of viscosity variations during the course of magma mixing suggest that mixing dynamics and the degree of magma interaction on all scales were established at the beginning of the recharge event.

Fatigue crack closure behavior at high stress ratios

NASA Technical Reports Server (NTRS)

Turner, C. Christopher; Carman, C. Davis; Hillberry, Ben M.

1988-01-01

Fatigue crack delay behavior at high stress ratio caused by single peak overloads was investigated in two thicknesses of 7475-T731 aluminum alloy. Closure measurements indicated no closure occurred before or throughout the overload plastic zones following the overload. This was further substantiated by comparing the specimen compliance following the overload with the compliance of a low R ratio test when the crack was fully open. Scanning electron microscope studies revealed that crack tunneling and possibly reinitiation of the crack occurred, most likely a result of crack-tip blunting. The number of delay cycles was greater for the thinner mixed mode stress state specimen than for the thicker plane strain stress state specimen, which is similar to low R ratio test results and may be due to a larger plastic zone for the mixed mode cased.

Quasi-horizontal transport and mixing in the Antarctic stratosphre

NASA Technical Reports Server (NTRS)

Chen, Ping; Holton, James R.; O'Neill, Alan; Swinbank, Richard

1994-01-01

The quasi-horizontal transport and mixing properties of the Antarctic stratosphere are investigated with a simi-Lagrangian transport model and a 'contour advection' technique for the winter and spring of 1992 using analyzed winds from the United Kingdom Meteorological Office data assimiliation system. Transport calculations show that passive tracers are well mixed inside the polar vortex as well as in the midlatitude 'surf zone.' A the vortex edge, strong radial gradients in the tracer fields are well preserved, and their evolutions follow that of the potential vorticity until some time after the breakdown of the polar vortex. In the middle stratosphere there is little tracer exchange across the vortex edge in August and September. Some vortex air is eroded into the surf zone in filamentary form in October, and very strong exchange of air occurs between high and middle latitudes in November. In the lower stratosphere the vortex is not so isolated from the midlatitudes as in the middle stratosphere, and there is more mass exchange across the vortex edge. Calculations of the lengthening of material contours using the contour advection technique show that in the middle stratosphere, strong stirring (i.e., stretching and folding of material elements) occurs in the inner vortex, while the strongest stirring occurs in the midlatitude surf zone and the weakest occurs at the vortex edge. In the lower strtosphere, strong stirring occurs in the inner vortex. Stirring is moderate at the vortex edge and in the midlatitudes.

Lithofacies Associations and Depositional Environments of the Neogene Molasse succession, Pishin Belt, northwestern Pakistan

NASA Astrophysics Data System (ADS)

Kasi, A.; Kassi, A.; Friis, H.; Umar, M.

2013-12-01

The Pishin Belt is a NE-SW trending mixed flysch and molasse basin, situated at the northwestern part of Pakistan, bordered by Afghan Block of the Eurasian Plate in the west and Indian Plate in the east. Western boundary of the belt is marked by the well-known Chaman Transform Fault, whereas the Zhob Valley Thrust and Muslim Bagh-Zhob Ophiolite mark the eastern boundary. The Belt is divisible into six tectono-stratigraphic zones bounded by major thrusts. Muslim Bagh-Zhob Ophiolite is the base and Zone-I of this belt. Zone-II comprises shallow marine and flysch successions of the Eocene Nisai Formation and Oligocene Khojak Formation. The Early to Middle Miocene Dasht Murgha group comprises Zone-III, the Late Miocene-Pliocene Malthanai formation comprises Zone-IV, the Pleistocene Bostan Formation makes Zone-V, and the flat-laying Holocene deposits of the Zhob Valley comprise Zone-VI. The Neogene molasse successions of the Pishin Belt include the Dasht Murgha group, Malthanai formation and Bostan Formation; these are mostly composed of sandstone, claystone and conglomerate lithologies. Sandstones have been classified as lithic arenites and their QFL values suggest quartzolithic composition. Twelve distinct lithofacies have been recognized in the succession and thus grouped into four types of facies associations. Lithofacies include clast-supported massive gravel (Gcm), clast-supported crudely bedded gravel (Gh), cross-stratified conglomerate (Gt and Gp), trough cross-stratified sandstone (St), planar cross-stratified sandstone (Sp), ripple cross-laminated sandstone (Sr), horizontally stratified sandstone (Sh), low-angle cross-stratified sandstone (Sl), massive sandstones (Sm), massive mudstone and siltstone (Fm) and paleosol carbonate (P). The lithofacies associations include channel facies association (CHA), crevasse-splay facies association (CSA), natural-levee facies association (LVA) and floodplain facies association (FPA). The lithofacies associations suggest that the Dasht Murgha group was deposited by a sandy braided to mixed-load high-sinuosity fluvial system, the Malthanai formation by a mixed-load high-sinuosity fluvial system and Bostan Formation by gravelly braided channels of a coalescing alluvial fan system. We propose that prolonged and continued collision of the Indian Plate with the Afghan Block of the Eurasian Plate resulted in the closure of the Katawaz Remnant Ocean (the southwestern extension of the Neo-Tethys) in the Early Miocene. Uplifted orogens of the Muslim Bagh-Zhob Ophiolite and marine successions of the Nisai and Khojak formations served as the major source terrains for the Miocene through Holocene molasse succession in the south and southeast verging successive thrust-bound foreland basins at the outer most extremity of the Pishin Belt.

Reconstruction of far-field tsunami amplitude distributions from earthquake sources

USGS Publications Warehouse

Geist, Eric L.; Parsons, Thomas E.

2016-01-01

The probability distribution of far-field tsunami amplitudes is explained in relation to the distribution of seismic moment at subduction zones. Tsunami amplitude distributions at tide gauge stations follow a similar functional form, well described by a tapered Pareto distribution that is parameterized by a power-law exponent and a corner amplitude. Distribution parameters are first established for eight tide gauge stations in the Pacific, using maximum likelihood estimation. A procedure is then developed to reconstruct the tsunami amplitude distribution that consists of four steps: (1) define the distribution of seismic moment at subduction zones; (2) establish a source-station scaling relation from regression analysis; (3) transform the seismic moment distribution to a tsunami amplitude distribution for each subduction zone; and (4) mix the transformed distribution for all subduction zones to an aggregate tsunami amplitude distribution specific to the tide gauge station. The tsunami amplitude distribution is adequately reconstructed for four tide gauge stations using globally constant seismic moment distribution parameters established in previous studies. In comparisons to empirical tsunami amplitude distributions from maximum likelihood estimation, the reconstructed distributions consistently exhibit higher corner amplitude values, implying that in most cases, the empirical catalogs are too short to include the largest amplitudes. Because the reconstructed distribution is based on a catalog of earthquakes that is much larger than the tsunami catalog, it is less susceptible to the effects of record-breaking events and more indicative of the actual distribution of tsunami amplitudes.

Localized zones of denitrification in a floodplain aquifer in southern Wisconsin, USA

NASA Astrophysics Data System (ADS)

Craig, Laura; Bahr, Jean M.; Roden, Eric E.

2010-12-01

A floodplain aquifer within an agricultural watershed near Madison, Wisconsin (USA), was studied to determine whether denitrification was occurring below the surface organic layer. Groundwater levels and concentrations of O2, Cl-, NO{3/-}, SO{4/2-}, dissolved organic carbon (DOC), and major cations were monitored over a 1-year period along a 230-m transect between an agricultural field and a stream discharge point. Seventeen groundwater samples were analyzed for δ15NNO3 and δ18ONO3 composition. Samples in which NO{3/-} was too low for stable isotope analysis were analyzed for excess dissolved N2. Groundwater NO{3/-} concentrations declined between the agricultural field and the discharge point. Chloride and δ15NNO3/δ18ONO3 data indicated that the drop in NO{3/-} was caused primarily by dilution of shallow NO{3/-}-rich water with deeper, NO{3/-}-depleted groundwater. Two localized zones of denitrification were identified in the upland-wetland transition by their δ15NNO3 and δ18ONO3 signatures, and two in the stream hyporheic zone by the presence of excess dissolved N2. The combined stratigraphic, hydrologic, and geochemical data in these locations correspond to groundwater mixing zones where NO{3/-} is delivered to subsurface layers that support denitrification fueled by dissolved (e.g. DOC or dissolved Fe(II)) and/or solid-phase (e.g. particulate organic carbon, solid-associated Fe(II), or pyrite) electron donors.

Redistribution of Iron and Titanium in High-Pressure Ultramafic Rocks

NASA Astrophysics Data System (ADS)

Crossley, Rosalind J.; Evans, Katy A.; Reddy, Steven M.; Lester, Gregory W.

2017-11-01

The redox state of iron in high-pressure serpentinites, which host a significant proportion of Fe3+ in subduction zones, can be used to provide an insight into iron cycling and constrain the composition of subduction zone fluids. In this study, we use oxide and silicate mineral textures, interpretation of mineral parageneses, mineral composition data, and whole rock geochemistry of high-pressure retrogressed ultramafic rocks from the Zermatt-Saas Zone to constrain the distribution of iron and titanium, and iron oxidation state. These data provide an insight on the oxidation state and composition of fluids at depth in subduction zones. Oxide minerals host the bulk of iron, particularly Fe3+. The increase in mode of magnetite and observation of magnetite within antigorite veins in the investigated ultramafic samples during initial retrogression is most consistent with oxidation of existing iron within the samples during the infiltration of an oxidizing fluid since it is difficult to reconcile addition of Fe3+ with the known limited solubility of this species. However, high Ti contents are not typical of serpentinites and also cannot be accounted for by simple mixing of a depleted mantle protolith with the nearby Allalin gabbro. Titanium-rich phases coincide with prograde metamorphism and initial exhumation, implying the early seafloor and/or prograde addition and late mobilization of Ti. If Ti addition has occurred, then the introduction of Fe3+, also generally considered to be immobile, cannot be disregarded. We explore possible transport vectors for Ti and Fe through mineral texture analysis.

Evaluation of ultrastructural hepatic response to environmental toxicants in wild cotton rats (Sigmodon hispidus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elangbam, C.S.; Qualls, C.W.; Confer, A.W.

1991-08-01

Hepatic lobules are composed of hepatocytes organized in three microcirculatory zones (periportal, midzonal, and centrilobular). The hepatocytes in each of these zones contain enzymes which are involved in various biochemical reactions. The predominant location of the mixed-function oxidation system in the liver lobule is the centrilobular zone. Ultrastructural changes in the hepatocytes not only correlate with biochemical events of detoxification but also with toxic effects of a parent compound or its metabolites. The objectives of this study was to characterize the ultrastructural alterations in the liver of wild cotton rats (Sigmodon hispidus) following exposure to polychlorinated biphenyls (PCB) contaminated habitat.

Combustion chamber and thermal vapor stream producing apparatus and method

DOEpatents

Sperry, John S.; Krajicek, Richard W.; Cradeur, Robert R.

1978-01-01

A new and improved method and apparatus for burning a hydrocarbon fuel for producing a high pressure thermal vapor stream comprising steam and combustion gases for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, wherein a high pressure combustion chamber having multiple refractory lined combustion zones of varying diameters is provided for burning a hydrocarbon fuel and pressurized air in predetermined ratios injected into the chamber for producing hot combustion gases essentially free of oxidizing components and solid carbonaceous particles. The combustion zones are formed by zones of increasing diameters up a final zone of decreasing diameter to provide expansion zones which cause turbulence through controlled thorough mixing of the air and fuel to facilitate complete combustion. The high pressure air and fuel is injected into the first of the multiple zones where ignition occurs with a portion of the air injected at or near the point of ignition to further provide turbulence and more complete combustion.

Viewing zones in three-dimensional imaging systems based on lenticular, parallax-barrier, and microlens-array plates.

PubMed

Son, Jung-Young; Saveljev, Vladmir V; Kim, Jae-Soon; Kim, Sung-Sik; Javidi, Bahram

2004-09-10

The viewing zone of autostereoscopic imaging systems that use lenticular, parallax-barrier, and microlens-array plates as the viewing-zone-forming optics is analyzed in order to verify the image-quality differences between different locations of the zone. The viewing zone consists of many subzones. The images seen at most of these subzones are composed of at least one image strip selected from the total number of different view images displayed. These different view images are not mixed but patched to form a complete image. This image patching deteriorates the quality of the image seen at different subzones. We attempt to quantify the quality of the image seen at these viewing subzones by taking the inverse of the number of different view images patched together at different subzones. Although the combined viewing zone can be extended to almost all of the front space of the imaging system, in reality it is limited mainly by the image quality.

Yield gap analyses to estimate attainable bovine milk yields and evaluate options to increase production in Ethiopia and India.

PubMed

Mayberry, Dianne; Ash, Andrew; Prestwidge, Di; Godde, Cécile M; Henderson, Ben; Duncan, Alan; Blummel, Michael; Ramana Reddy, Y; Herrero, Mario

2017-07-01

Livestock provides an important source of income and nourishment for around one billion rural households worldwide. Demand for livestock food products is increasing, especially in developing countries, and there are opportunities to increase production to meet local demand and increase farm incomes. Estimating the scale of livestock yield gaps and better understanding factors limiting current production will help to define the technological and investment needs in each livestock sector. The aim of this paper is to quantify livestock yield gaps and evaluate opportunities to increase dairy production in Sub-Saharan Africa and South Asia, using case studies from Ethiopia and India. We combined three different methods in our approach. Benchmarking and a frontier analysis were used to estimate attainable milk yields based on survey data. Household modelling was then used to simulate the effects of various interventions on dairy production and income. We tested interventions based on improved livestock nutrition and genetics in the extensive lowland grazing zone and highland mixed crop-livestock zones of Ethiopia, and the intensive irrigated and rainfed zones of India. Our analyses indicate that there are considerable yield gaps for dairy production in both countries, and opportunities to increase production using the interventions tested. In some cases, combined interventions could increase production past currently attainable livestock yields.

Performance comparison of single-stage mixed-refrigerant Joule-Thomson cycle and reverse Brayton cycle for cooling 80 to 120 K temperature-distributed heat loads

NASA Astrophysics Data System (ADS)

Wang, H. C.; Chen, G. F.; Gong, M. Q.; Li, X.

2017-12-01

Thermodynamic performance comparison of single-stage mixed-refrigerant Joule-Thomson cycle (MJTR) and pure refrigerant reverse Brayton cycle (RBC) for cooling 80 to 120 K temperature-distributed heat loads was conducted in this paper. Nitrogen under various liquefaction pressures was employed as the heat load. The research was conducted under nonideal conditions by exergy analysis methods. Exergy efficiency and volumetric cooling capacity are two main evaluation parameters. Exergy loss distribution in each process of refrigeration cycle was also investigated. The exergy efficiency and volumetric cooling capacity of MJTR were obviously superior to RBC in 90 to 120 K temperature zone, but still inferior to RBC at 80 K. The performance degradation of MJTR was caused by two main reasons: The high fraction of neon resulted in large entropy generation and exergy loss in throttling process. Larger duty and WLMTD lead to larger exergy losses in recuperator.

Counterintuitive effect of fall mixed layer deepening on eukaryotic new production in the Sargasso Sea

NASA Astrophysics Data System (ADS)

Fawcett, S. E.; Lomas, M. W.; Ward, B. B.; Sigman, D. M.

2012-12-01

The Sargasso Sea is characterized by a short period of deep vertical mixing in the late winter and early spring, followed by strong thermal stratification during the summer. Stratification persists into the fall, impeding the upward flux of nitrate from depth so that recycled forms of nitrogen (N) such as ammonium are thought to support most primary production. We collected particles from surface waters during March, July, October, and December, used flow cytometry to separate the prokaryotic and eukaryotic phytoplankton, and analyzed their respective 15N/14N. In all months, the 15N/14N of the prokaryotic genera, Prochlorococcus and Synechococcus, was low, indicative of reliance on recycled N throughout the year. In July, the 15N/14N of eukaryotic phytoplankton was variable but consistently higher than that of the prokaryotes, reflecting eukaryotic consumption of subsurface nitrate. Two eukaryotic profiles from October and December were similar to those from July. In three other fall profiles, the eukaryotes had a 15N/14N similar to that of the prokaryotes, suggesting a switch toward greater reliance on recycled N. This change in the dominant N source supporting eukaryotic production appears to be driven by the density structure of the upper water column. The very shallow low-density surface "mixed layer" (≤20 m) that develops in early-to-mid summer does not contribute to stratification at the base of the euphotic zone, and subsurface nitrate can mix up into the lower euphotic zone, facilitating continued production. The deepening of the mixed layer into the fall, typically taken as an indication of weaker overall stratification, actually strengthens the isolation of the euphotic zone as a whole, reducing the upward supply of nitrate to the photosynthetically active layer. The same counterintuitive dynamic explains the latitudinal patterns in a set of three October depth profiles. Two northern stations (32°N and 27°N) were characterized by a thick, low-density surface layer, and the 15N/14N of all phytoplankton was low, consistent with assimilation of recycled N. The southernmost station (23°N) had a shallower mixed layer, and eukaryote 15N/14N reflects growth on nitrate. In the subtropics, evidence for the direct supply of nitrate into surface waters in the face of the strong upper ocean stratification has long been sought. Our N isotope results suggest a mechanism by which subsurface nitrate is imported into shallow waters. This interpretation offers a new perspective on the relationship between euphotic zone stratification and nitrate assimilation, implying that significant new production occurs under conditions previously assumed to drive oligotrophy.

Ibrutinib in Treating Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma in Patients With HIV Infection

ClinicalTrials.gov

2015-08-18

Adult B Acute Lymphoblastic Leukemia; Chronic Lymphocytic Leukemia; Cutaneous B-Cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue; HIV Infection; Intraocular Lymphoma; Multicentric Angiofollicular Lymphoid Hyperplasia; Nodal Marginal Zone Lymphoma; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; Refractory Plasma Cell Myeloma; Small Intestinal Lymphoma; Splenic Marginal Zone Lymphoma; Testicular Lymphoma; Waldenstrom Macroglobulinemia

Free-zone electrophoresis of animal cells. 1: Experiments on cell-cell interactions

NASA Technical Reports Server (NTRS)

Todd, P. W.; Hjerten, S.

1985-01-01

The electrophoretically migrating zones wasa monitored. The absence of fluid flows in the direction of migration permits direct measurement of electrophoretic velocities of any material. Sedimentation is orthogonal to electrokinetic motion and the effects of particle-particle interaction on electrophoretic mobility is studied by free zone electrophoresis. Fixed erythrocytes at high concentrations, mixtures of fixed erythrocytes from different animal species, and mixtures of cultured human cells were studied in low ionic strength buffers. The electrophoretic velocity of fixed erythrocytes was not altered by increasing cell concentration or by the mixing of erythrocytes from different species. When zones containing cultured human glial cells and neuroblastoma cells are permitted to interact during electrophoresis, altered migration patterns occur. It is found that cell-cell interactions depends upon cell type.

Water chemistry at Snowshoe Mountain, Colorado: mixed processes in a common bedrock

USGS Publications Warehouse

Hoch, A.R.; Reddy, M.M.

2001-01-01

At Snowshoe Mountain the primary bedrock is quite homogeneous, but weathering processes vary as waters moves through the soils, vadose zone and phreatic zone of the subsurface. In the thin soil, physical degradation of tuff facilitates preferential dissolution of potassium ion from glass within the rock matrix, while other silicate minerals remain unaltered. In the vadose zone, in the upper few meters of fractured bedrock, dilute water infiltrates during spring snowmelt and summer storms, leading to preferential dissolution of augite exposed on fracture surfaces. Deeper yet, in the phreatic zone of the fractured bedrock, Pleistocene calcite fracture fillings dissolve, and dioctahedral and trioctahedral clays form as penetrative weathering alters feldspar and pyroxene. Alkalinity is generated and silica concentrations are buffered by mineral alteration reactions.

Comparisons between thermodynamic and one-dimensional combustion models of spark-ignition engines

NASA Technical Reports Server (NTRS)

Ramos, J. I.

1986-01-01

Results from a one-dimensional combustion model employing a constant eddy diffusivity and a one-step chemical reaction are compared with those of one-zone and two-zone thermodynamic models to study the flame propagation in a spark-ignition engine. One-dimensional model predictions are found to be very sensitive to the eddy diffusivity and reaction rate data. The average mixing temperature found using the one-zone thermodynamic model is higher than those of the two-zone and one-dimensional models during the compression stroke, and that of the one-dimensional model is higher than those predicted by both thermodynamic models during the expansion stroke. The one-dimensional model is shown to predict an accelerating flame even when the front approaches the cold cylinder wall.

Genetically Modified T-cell Infusion Following Peripheral Blood Stem Cell Transplant in Treating Patients With Recurrent or High-Risk Non-Hodgkin Lymphoma

ClinicalTrials.gov

2018-01-26

Adult Grade III Lymphomatoid Granulomatosis; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Post-transplant Lymphoproliferative Disorder; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Testicular Lymphoma; Waldenström Macroglobulinemia

East Pacific rise at 21°N: the volcanic, tectonic, and hydrothermal processes of the central axis

USGS Publications Warehouse

Ballard, Richard D.; Francheteau, Jean; Juteau, Tierre; Rangan, Claude; Normark, William

1981-01-01

Photographs obtained by the ANGUS survey system at 21°N reveal many similarities to the geological processes delineated at other spreading centers and in particular those observed in the Galapagos Rift at 86°W. The region of recent volcanism is restricted to a narrow zone (Zone 1) approximately 1 km wide. This suggests that the width of the magma chamber feeding these flows is also narrow at the top. Variations in sediment cover are used to subdivide the flows within Zone 1 into three sheet-flow/pillow-flow pairs. The youngest pair appears to have erupted form a linear fissure 8 km long running parallel to the valley axis. This fissure is part of a larger en echelon pattern of eruptive fissures. Active hydrothermal vents associated with the youngest flows are situated directly above the apparent eruptive fissure. The high (350°C) temperature for some of the fluids exiting from the vents suggests a highly restricted circulation system involving, at times, little to no mixing with cold seawater. The lava terrain in the remainder of Zone 1 and bordering regions is characterized by extensive fracturing, further suggesting a narrow upper dimension to the magma chamber and also that subsurface hydrothermal deposition of massive sulfides may lead to a reduction in the mixing processes.

East Pacific Rise at 21 °N: The volcanic, tectonic, and hydrothermal processes of the central axis

USGS Publications Warehouse

Ballard, Richard D.; Francheteau, Jean; Juteau, Tierre; Rangan, Claude; Normark, William R.

1981-01-01

Photographs obtained by the ANGUS survey system at 21°N reveal many similarities to the geological processes delineated at other spreading centers and in particular those observed in the Galapagos Rift at 86°W. The region of recent volcanism is restricted to a narrow zone (Zone l) approximately l km wide. This suggests that the width of the magma chamber feeding these flows is also narrow at the top. Variations in sediment cover are used to subdivide the flows within Zone 1 into three sheet-flow/pillow-flow pairs. The youngest pair appears to have erupted form a linear fissure 8 km long running parallel to the valley axis. This fissure is part of a larger en echelon pattern of eruptive fissures. Active hydrothermal vents associated with the youngest flows are situated directly above the apparent eruptive fissure. The high (350°C) temperature for some of the fluids exiting from the vents suggests a highly restricted circulation system involving, at times, little to no mixing with cold seawater. The lava terrain in the remainder of Zone l and bordering regions is characterized by extensive fracturing, further suggesting a narrow upper dimension to the magma chamber and also that subsurface hydrothermal deposition of massive sulfides may lead to a reduction in the mixing processes.

Speculations on the dynamics of Jupiter's atmosphere from 1 to 100 bars

NASA Astrophysics Data System (ADS)

Ingersoll, A. P.

2017-12-01

The latitude-altitude map of ammonia mixing ratio shows an ammonia-rich zone at 0-5°N, with mixing ratios of 320-340 ppm, extending from 40-60 bars up to the ammonia cloud base at 0.7 bars. Ammonia-poor air occupies a belt from 5-20°N. We argue that downdrafts as well as updrafts are needed in the 0-5°N zone to balance the upward ammonia flux. Outside the 0-20°N region, the belt-zone signature is weaker. At latitudes out to ±40°, there is an ammonia-rich layer from cloud base down to 2 bars which we argue is caused by falling precipitation. Below, there is an ammonia-poor layer with a minimum at 6 bars. Unanswered questions include how the ammonia-poor layer is maintained, why the belt-zone structure is barely evident in the ammonia distribution outside 0-20°N, and how the internal heat is transported through the ammonia-poor layer to the ammonia cloud base. Here we speculate on possible answers, including double-diffusive convection, deep abyssal overturning, and mass loading of heavy condensates in a hydrogen/helium atmosphere. Ingersoll, A. P. et al. (2017). Implications of the ammonia distribution on Jupiter from 1 to 100 bars as measured by the Juno microwave radiometer. Geophys. Res. Lett., in press, doi: 10.1002/2017GL074277.

East Pacific rise at 21°N: The volcanic, tectonic, and hydrothermal processes of the central axis

NASA Astrophysics Data System (ADS)

Ballard, Robert D.; Francheteau, Jean; Juteau, Tierre; Rangan, Claude; Normark, William

1981-09-01

Photographs obtained by the ANGUS survey system at 21°N reveal many similarities to the geological processes delineated at other spreading centers and in particular those observed in the Galapagos Rift at 86°W. The region of recent volcanism is restricted to a narrow zone (Zone 1) approximately 1 km wide. This suggests that the width of the magma chamber feeding these flows is also narrow at the top. Variations in sediment cover are used to subdivide the flows within Zone 1 into three sheet-flow/pillow-flow pairs. The youngest pair appears to have erupted form a linear fissure 8 km long running parallel to the valley axis. This fissure is part of a larger en echelon pattern of eruptive fissures. Active hydrothermal vents associated with the youngest flows are situated directly above the apparent eruptive fissure. The high (350°C) temperature for some of the fluids exiting from the vents suggests a highly restricted circulation system involving, at times, little to no mixing with cold seawater. The lava terrain in the remainder of Zone 1 and bordering regions is characterized by extensive fracturing, further suggesting a narrow upper dimension to the magma chamber and also that subsurface hydrothermal deposition of massive sulfides may lead to a reduction in the mixing processes.

Genetically Modified Peripheral Blood Stem Cell Transplant in Treating Patients With HIV-Associated Non-Hodgkin or Hodgkin Lymphoma

ClinicalTrials.gov

2015-05-06

Adult Nasal Type Extranodal NK/T-cell Lymphoma; AIDS-related Diffuse Large Cell Lymphoma; AIDS-related Diffuse Mixed Cell Lymphoma; AIDS-related Diffuse Small Cleaved Cell Lymphoma; AIDS-related Immunoblastic Large Cell Lymphoma; AIDS-related Lymphoblastic Lymphoma; AIDS-related Peripheral/Systemic Lymphoma; AIDS-related Small Noncleaved Cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Hepatosplenic T-cell Lymphoma; HIV-associated Hodgkin Lymphoma; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Noncutaneous Extranodal Lymphoma; Peripheral T-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage I AIDS-related Lymphoma; Stage II AIDS-related Lymphoma; Stage III AIDS-related Lymphoma; Stage IV AIDS-related Lymphoma; T-cell Large Granular Lymphocyte Leukemia; Testicular Lymphoma; Waldenström Macroglobulinemia

Overview of surface measurements and spatial characterization of submicrometer particulate matter during the DISCOVER-AQ 2013 campaign in Houston, TX.

PubMed

Leong, Y J; Sanchez, N P; Wallace, H W; Karakurt Cevik, B; Hernandez, C S; Han, Y; Flynn, J H; Massoli, P; Floerchinger, C; Fortner, E C; Herndon, S; Bean, J K; Hildebrandt Ruiz, L; Jeon, W; Choi, Y; Lefer, B; Griffin, R J

2017-08-01

The sources of submicrometer particulate matter (PM 1 ) remain poorly characterized in the industrialized city of Houston, TX. A mobile sampling approach was used to characterize PM 1 composition and concentration across Houston based on high-time-resolution measurements of nonrefractory PM 1 and trace gases during the DISCOVER-AQ Texas 2013 campaign. Two pollution zones with marked differences in PM 1 levels, character, and dynamics were established based on cluster analysis of organic aerosol mass loadings sampled at 16 sites. The highest PM 1 mass concentrations (average 11.6 ± 5.7 µg/m 3 ) were observed to the northwest of Houston (zone 1), dominated by secondary organic aerosol (SOA) mass likely driven by nighttime biogenic organonitrate formation. Zone 2, an industrial/urban area south/east of Houston, exhibited lower concentrations of PM 1 (average 4.4 ± 3.3 µg/m 3 ), significant organic aerosol (OA) aging, and evidence of primary sulfate emissions. Diurnal patterns and backward-trajectory analyses enable the classification of airmass clusters characterized by distinct PM sources: biogenic SOA, photochemical aged SOA, and primary sulfate emissions from the Houston Ship Channel. Principal component analysis (PCA) indicates that secondary biogenic organonitrates primarily related with monoterpenes are predominant in zone 1 (accounting for 34% of the variability in the data set). The relevance of photochemical processes and industrial and traffic emission sources in zone 2 also is highlighted by PCA, which identifies three factors related with these processes/sources (~50% of the aerosol/trace gas concentration variability). PCA reveals a relatively minor contribution of isoprene to SOA formation in zone 1 and the absence of isoprene-derived aerosol in zone 2. The relevance of industrial amine emissions and the likely contribution of chloride-displaced sea salt aerosol to the observed variability in pollution levels in zone 2 also are captured by PCA. This article describes an urban-scale mobile study to characterize spatial variations in submicrometer particulate matter (PM 1 ) in greater Houston. The data set indicates substantial spatial variations in PM 1 sources/chemistry and elucidates the importance of photochemistry and nighttime oxidant chemistry in producing secondary PM 1 . These results emphasize the potential benefits of effective control strategies throughout the region, not only to reduce primary emissions of PM 1 from automobiles and industry but also to reduce the emissions of important secondary PM 1 precursors, including sulfur oxides, nitrogen oxides, ammonia, and volatile organic compounds. Such efforts also could aid in efforts to reduce mixing ratios of ozone.

When does eruption run-up begin? Multidisciplinary insight from the 1999 eruption of Shishaldin volcano

NASA Astrophysics Data System (ADS)

Rasmussen, Daniel J.; Plank, Terry A.; Roman, Diana C.; Power, John A.; Bodnar, Robert J.; Hauri, Erik H.

2018-03-01

During the run-up to eruption, volcanoes often show geophysically detectable signs of unrest. However, there are long-standing challenges in interpreting the signals and evaluating the likelihood of eruption, especially during the early stages of volcanic unrest. Considerable insight can be gained from combined geochemical and geophysical studies. Here we take such an approach to better understand the beginning of eruption run-up, viewed through the lens of the 1999 sub-Plinian basaltic eruption of Shishaldin volcano, Alaska. The eruption is of interest due to its lack of observed deformation and its apparent long run-up time (9 months), following a deep long-period earthquake swarm. We evaluate the nature and timing of recharge by examining the composition of 138 olivine macrocrysts and 53 olivine-hosted melt inclusions and through shear-wave splitting analysis of regional earthquakes. Magma mixing is recorded in three crystal populations: a dominant population of evolved olivines (Fo60-69) that are mostly reversely zoned, an intermediate population (Fo69-76) with mixed zonation, and a small population of normally zoned more primitive olivines (Fo76-80). Mixing-to-eruption timescales are obtained through modeling of Fe-Mg interdiffusion in 78 olivines. The large number of resultant timescales provides a thorough record of mixing, demonstrating at least three mixing events: a minor event ∼11 months prior to eruption, overlapping within uncertainty with the onset of deep long-period seismicity; a major event ∼50 days before eruption, coincident with a large (M5.2) shallow earthquake; and a final event about a week prior to eruption. Shear-wave splitting analysis shows a change in the orientation of the local stress field about a month after the deep long-period swarm and around the time of the M5.2 event. Earthquake depths and vapor saturation pressures of Raman-reconstructed melt inclusions indicate that the recharge magma originated from depths of at least 20 km, and that mixing with a shallow magma or olivine cumulates occurred in or just below the edifice (<3 km depth). Deformation was likely outside the spatial and temporal resolution of the satellite measurements. Prior to eruption magma was stored over a large range of depths (∼0-2.5 km below the summit), suggesting a shallow, vertical reservoir that could provide another explanation for the lack of detectable deformation. The earliest sign of unrest (deep long-period seismicity) coincides temporally with magmatic activity (magma mixing and a change in the local stress state), possibly indicating the beginning of eruption run-up. The more immediate run-up began with the major recharge event ∼50 days prior to eruption, after which the signs of unrest became continuous. This timescale is long compared to the seismic run-up to other basaltic eruptions (typically hours to days). Other volcanoes classified as open-system, based on their lack of precursory deformation, also tend to have relatively long run-up durations, which may be related to the time required to fill the shallow reservoir with magmas sourced from greater depth.

Shallow Water UXO Technology Demonstration Site Scoring Record No. 7

DTIC Science & Technology

2007-05-01

categories: ferrous, nonferrous , and mixed metals . The ferrous and nonferrous items are further divided into the three weight zones as presented in... nonferrous component and could reasonably be encountered in a range area. The mixed- metals clutter was placed in the open water area only. TABLE 1-3...Table 1-4, and distributed throughout all test areas. Most of this clutter is composed of ordnance components; however, industrial scrap metal and

The nucleation of "fast" and "slow" stick slip instabilities in sheared granular aggregates

NASA Astrophysics Data System (ADS)

Korkolis, Evangelos; Ampuero, Jean-Paul; Niemeijer, André

2017-04-01

Seismological observations in the past few decades have revealed a diversity of slip behaviors of faults, involving interactions and transition between slow to fast slip phenomena. Field studies show that exhumed fault zones comprise mixtures of materials with variable frictional strength and stability. Emergent models of slip diversity emphasize the role of heterogeneities of fault zone properties and the potential interactions between seismic and aseismic deformation. Here, we develop analog laboratory experiments to study the mechanics of heterogeneous faults with the goal to identify factors controlling their slip stability and rupture style. We report on results from room temperature sliding experiments using a rotary shear apparatus. We simulated gouge heterogeneity by using materials with different frictional strength and stability. At room temperature conditions, dry glass beads typically stick slip, whereas dry granular calcite exhibits stable sliding. The peak strength of glass beads aggregates is typically lower than that of granular calcite aggregates. Our samples consisted of a layer of glass beads sandwiched between two layers of granular calcite. The initial particle size was between 100 and 200 μm for both materials and the initial thickness of each layer was about 1.5 mm. We tested our layered aggregates under 1 to 7 MPa normal stress and at sliding velocities between 1 and 100 μm/s. Within that range of conditions, high normal stress and slow sliding velocities promoted fast, regular stick slip. For normal stress values of less than about 4 MPa, the recurrence time and stress drop of stick slips became irregular, particularly at sliding rates above 20 μm/s. As the accumulated shear displacement increased, slip events became slower and the magnitudes of their stress drop, compaction and slip distance decreased. We recorded acoustic emissions (AEs) associated with each slip event (fast and slow) and estimated their source azimuth. AE activity was distributed in several clusters, some of which remained stationary, whereas others appeared to migrate with increasing shear displacement. We performed post-mortem microstructural analysis (tabletop SEM) of select AE nucleation sites and found significant mixing of glass beads with the calcite layer abutting the rotating piston ring. No mixing was observed between the glass beads and the calcite layer on the opposite side, nor any features that would indicate strain localization along the interface of the calcite and the adjacent stationary piston. These results show that the frictional behavior of our aggregates changed from fast to slow slip as the amount of glass beads mixed with granular calcite increased. Migrating AE clusters imply that nucleation occurred within the mixed calcite-glass beads layer, where most of the shear strain appears to have been accommodated, whereas stationary clusters probably originated within the adjacent, more slowly deforming layer of glass beads. This suggests that AEs belonging to migrating clusters were perhaps triggered by stress changes due to the gradual mixing of the two sample constituents. This process may explain migrating seismicity in natural fault zones.

Sand Island WWTP, Honolulu, HI: HI0020117

EPA Pesticide Factsheets

Authorization to Discharge under the National Pollutant Discharge Elimination System and Zone of Mixing for the City and County of Honolulu Department of Environmental Services Sand Island Wastewater Treatment PlantNPDES Permit No. HI0020117

Microscale Characterization and Trace Element Distribution in Bacteriogenic Ferromanganese Coatings on Sand Grains from an Intertidal Zone of the East China Sea

PubMed Central

Yuan, Linxi; Sun, Liguang; Fortin, Danielle; Wang, Yuhong; Yin, Xuebin

2015-01-01

An ancient wood layer dated at about 5600 yr BP by accelerator mass spectrometry (AMS) 14C was discovered in an intertidal zone of the East China Sea. Extensive and horizontally stratified sediments with black color on the top and yellowish-red at the bottom, and some nodule-cemented concretions with brown surface and black inclusions occurred in this intertidal zone. Microscale analysis methods were employed to study the microscale characterization and trace element distribution in the stratified sediments and concretions. Light microscopy, scanning electron microscopy (SEM) and backscattered electron imaging (BSE) revealed the presence of different coatings on the sand grains. The main mineral compositions of the coatings were ferrihydrite and goethite in the yellowish-red parts, and birnessite in the black parts using X-ray powder diffraction (XRD). SEM observations showed that bacteriogenic products and bacterial remnants extensively occurred in the coatings, indicating that bacteria likely played an important role in the formation of ferromanganese coatings. Post-Archean Australian Shale (PAAS)-normalized middle rare earth element (MREE) enrichment patterns of the coatings indicated that they were caused by two sub-sequential processes: (1) preferentially release of Fe-Mn from the beach rocks by fermentation of ancient woods and colloidal flocculation in the mixing water zone and (2) preferential adsorption of MREE by Fe-Mn oxyhydroxides from the seawater. The chemical results indicated that the coatings were enriched with Sc, V, Cr, Co, Ni, Cu, Zn, Ba, especially with respect to Co, Ni. The findings of the present study provide an insight in the microscale features of ferromanganese coatings and the Fe-Mn biogeochemical cycling during the degradation of buried organic matter in intertidal zones or shallow coasts. PMID:25786213

Biogeochemical flux and phytoplankton succession: A year-long sediment trap record in the Australian sector of the Subantarctic Zone

NASA Astrophysics Data System (ADS)

Wilks, Jessica V.; Rigual-Hernández, Andrés S.; Trull, Thomas W.; Bray, Stephen G.; Flores, José-Abel; Armand, Leanne K.

2017-03-01

The Subantarctic Zone (SAZ) plays a crucial role in global carbon cycling as a significant sink for atmospheric CO2. In the Australian sector, the SAZ exports large quantities of organic carbon from the surface ocean, despite lower algal biomass accumulation in surface waters than other Southern Ocean sectors. We present the first analysis of diatom and coccolithophore assemblages and seasonality, as well as the first annual quantification of bulk organic components of captured material at the base of the mixed layer (500 m depth) in the SAZ. Sediment traps were moored in the SAZ southwest of Tasmania as part of the long-term SAZ Project for one year (September 2003 to September 2004). Annual mass flux at 500 m and 2000 m was composed mainly of calcium carbonate, while biogenic silica made up on average <10% of material captured in the traps. Organic carbon flux was estimated at 1.1 g m-2 y-1 at 500 m, close to the estimated global mean carbon flux. Low diatom fluxes and high fluxes of coccoliths were consistent with low biogenic silica and high calcium carbonate fluxes, respectively. Diatoms and coccoliths were identified to species level. Diatom and coccolithophore sinking assemblages reflected some seasonal ecological succession. A theoretical scheme of diatom succession in live assemblages is compared to successional patterns presented in sediment traps. This study provides a unique, direct measurement of the biogeochemical fluxes and their main biological carbon vectors just below the winter mixed layer depth at which effective sequestration of carbon occurs. Comparison of these results with previous sediment trap deployments at the same site at deeper depths (i.e. 1000, 2000 and 3800 m) documents the changes particle fluxes experience in the lower "twilight zone" where biological processes and remineralisation of carbon reduce the efficiency of carbon sequestration.

Hydrological connectivity in the karst critical zone: an integrated approach

NASA Astrophysics Data System (ADS)

Chen, X.; Zhang, Z.; Soulsby, C.; Cheng, Q.; Binley, A. M.; Tao, M.

2017-12-01

Spatial heterogeneity in the subsurface is high, evidenced by specific landform features (sinkholes, caves etc.) and resulting in high variability of hydrological processes in space and time. This includes complex exchange of various flow sources (e.g. hillslope springs and depression aquifers) and fast conduit flow and slow fracture flow. In this paper we integrate various "state-of-the-art" methods to understand the structure and function of this understudied critical zone environment. Geophysical, hydrometric and hydrogeochemical tools are used to characterize the hydrological connectivity of the cockpit karst critical zone in a small catchment of Chenqi, Guizhou province, China. Geophysical surveys, using electrical resistivity tomography (ERT), identified the complex conduit networks that link flows between hillslopes and depressions. Statistical time series analysis of water tables and discharge responses at hillslope springs and in depression wells and underground channels showed different threshold responses of hillslope and depression flows. This reflected the differing relative contribution of fast and slow flow paths during rainfall events of varying magnitude in the hillslope epikarst and depression aquifer in dry and wet periods. This showed that the hillslope epikarst receives a high proportion of rainfall recharge and is thus a main water resource in the catchment during the drought period. In contrast, the depression aquifer receives fast, concentrated hillslope flows during large rainfall events during the wet period, resulting in the filling of depression conduits and frequent flooding. Hydrological tracer studies using water temperatures and stable water isotopes (δD and δ18O) corroborated this and provided quantitative information of the mixing proportions of various flow sources and insights into water travel times. This revealed how higher contributions of event "new" water (from hillslope springs and depression conduits displaces "old" pre-event water primarily from low permeability fissures and fractures), particularly during heavy rainfall. As the various water sources have contrasting water quality characteristics, these mixing and exchange processes have important implications for understanding and managing water quality in karst waters.

Hydrologic functioning of the deep Critical Zone and contributions to streamflow in a high elevation catchment: testing of multiple conceptual models

NASA Astrophysics Data System (ADS)

Dwivedi, R.; Meixner, T.; McIntosh, J. C.; Ferre, T. P. A.; Eastoe, C. J.; Minor, R. L.; Barron-Gafford, G.; Chorover, J.

2017-12-01

The composition of natural mountainous waters maintains important control over the water quality available to downstream users. Furthermore, the geochemical constituents of stream water in the mountainous catchments represent the result of the spatial and temporal evolution of critical zone structure and processes. A key problem is that high elevation catchments involve rugged terrain and are subject to extreme climate and landscape gradients; therefore, high density or high spatial resolution hydro-geochemical observations are rare. Despite such difficulties, the Santa Catalina Mountains Critical Zone Observatory (SCM-CZO), Tucson, AZ, generates long-term hydrogeochemical data for understanding not only hydrological processes and their seasonal characters, but also the geochemical impacts of such processes on streamflow chemical composition. Using existing instrumentation and hydrogeochemical observations from the last 9+ years (2009 through 2016 and an initial part of 2017), we employed a multi-tracer approach along with principal component analysis to identify water sources and their seasonal character. We used our results to inform hydrological process understanding (flow paths, residence times, and water sources) for our study site. Our results indicate that soil water is the largest contributor to streamflow, which is ephemeral in nature. Although a 3-dimensional mixing space involving precipitation, soil water, interflow, and deep groundwater end-members could explain most of the streamflow chemistry, geochemical complexity was observed to grow with catchment storage. In terms of processes and their seasonal character, we found soil water and interflow were the primary end-member contributors to streamflow in all seasons. Deep groundwater only contributes to streamflow at high catchment storage conditions, but it provides major ions such as Na, Mg, and Ca that are lacking in other water types. In this way, our results indicate that any future efforts aimed at explaining concentration-discharge behavior of our field site should consider at least three-dimensional mixing space or 4 end-members.

Salinization of groundwater around underground LPG storage caverns, Korea : statistical interpretation

NASA Astrophysics Data System (ADS)

Lee, J.; Chang, H.

2001-12-01

In this research, we investigate the reciprocal influence between groundwater flow and its salinization occurred in two underground cavern sites, using major ion chemistry, PCA for chemical analysis data, and cross-correlation for various hydraulic data. The study areas are two underground LPG storage facilities constructed in South Sea coast, Yosu, and West Sea coastal regions, Pyeongtaek, Korea. Considerably high concentration of major cations and anions of groundwaters at both sites showed brackish or saline water types. In Yosu site, some great chemical difference of groundwater samples between rainy and dry season was caused by temporal intrusion of high-saline water into propane and butane cavern zone, but not in Pyeongtaek site. Cl/Br ratios and δ 18O- δ D distribution for tracing of salinization source water in both sites revealed that two kind of saline water (seawater and halite-dissolved solution) could influence the groundwater salinization in Yosu site, whereas only seawater intrusion could affect the groundwater chemistry of the observation wells in Pyeongtaek site. PCA performed by 8 and 10 chemical ions as statistical variables in both sites showed that intensive intrusion of seawater through butane cavern was occurred at Yosu site while seawater-groundwater mixing was observed at some observation wells located in the marginal part of Pyeongtaek site. Cross-correlation results revealed that the positive relationship between hydraulic head and cavern operating pressure was far more conspicuous at propane cavern zone in both sites (65 ~90% of correlation coefficients). According to the cross-correlation results of Yosu site, small change of head could provoke massive influx of halite-dissolved solution from surface through vertically developed fracture networks. However in Pyeongtaek site, the pressure-sensitive observation wells are not completely consistent with seawater-mixed wells, and the hydraulic change of heads at these wells related to the operating pressure is highly associated with horizontal fault developed along the east-west line of propane cavern zone.

Radon as a natural tracer for underwater cave exploration and hypogenic cave formation

NASA Astrophysics Data System (ADS)

Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

2017-04-01

Using 222Rn as a natural tracer is a novel approach in underwater cave exploration and in the research of active hypogenic caves. The research area, the Molnár János cave is one of the largest caves of an unique hypogenic karst system, the Buda Thermal Karst (Budapest, Hungary). The cave system is mainly characterized by water-filled passages. The cave is located at one of the main discharge areas of the Buda Thermal Karst and the major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous complex hydrogeological studies and radon measurements in the cave system and in the spring established the highest radon concentration (71 Bq/L, where the average is 44 Bq/L) in the springwater. The origin of radon was identified in the form of iron-hydroxide containing biofilms, which form by mixing of waters and efficiently adsorb radium from the thermal water component and cause local radon anomalies. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and consequently high radon concentrations mark the active cave forming zones. The aim of the study was to use the radon as a natural tracer to locate active mixing and cave forming zones. Based on previous radon measurements it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore, the radon activity concentration mapping was carried out with the help of divers and involving that part of the cave which closest to the spring. Based on our measurements the highest radon concentration (84 Bq/L) ever was achieved in the springwater. Based on the radon concentration distribution direct connection and active karst conduit was established between the spring and the deepest room of the researched part of the cave, which was verified by artificial tracer as well. However, the distribution of radon in the cave passages shows lower concentrations (18-46 Bq/L) compared to the spring, therefore an addition deep inflow from a hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are supposed to be in the active cave formation (mixing) zone. The Buda Thermal Karst research was funded by the Hungarian Scientific Research Fund under the grant agreement no. NK 101356.

Underground structures increasing the intrinsic vulnerability of urban groundwater: Sensitivity analysis and development of an empirical law based on a groundwater age modelling approach

NASA Astrophysics Data System (ADS)

Attard, Guillaume; Rossier, Yvan; Eisenlohr, Laurent

2017-09-01

In a previous paper published in Journal of Hydrology, it was shown that underground structures are responsible for a mixing process between shallow and deep groundwater that can favour the spreading of urban contamination. In this paper, the impact of underground structures on the intrinsic vulnerability of urban aquifers was investigated. A sensitivity analysis was performed using a 2D deterministic modelling approach based on the reservoir theory generalized to hydrodispersive systems to better understand this mixing phenomenon and the mixing affected zone (MAZ) caused by underground structures. It was shown that the maximal extent of the MAZ caused by an underground structure is reached approximately 20 years after construction. Consequently, underground structures represent a long-term threat for deep aquifer reservoirs. Regarding the construction process, draining operations have a major impact and favour large-scale mixing between shallow and deep groundwater. Consequently, dewatering should be reduced and enclosed as much as possible. The role played by underground structures' dimensions was assessed. The obstruction of the first aquifer layer caused by construction has the greatest influence on the MAZ. The cumulative impact of several underground structures was assessed. It was shown that the total MAZ area increases linearly with underground structures' density. The role played by materials' properties and hydraulic gradient were assessed. Hydraulic conductivity, anisotropy and porosity have the strongest influence on the development of MAZ. Finally, an empirical law was derived to estimate the MAZ caused by an underground structure in a bi-layered aquifer under unconfined conditions. This empirical law, based on the results of the sensitivity analysis developed in this paper, allows for the estimation of MAZ dimensions under known material properties and underground structure dimensions. This empirical law can help urban planners assess the area of influence of underground structures and protect urban strategic reservoirs.

Rapakivi texture formation via disequilibrium melting in a contact partial melt zone, Antarctica

NASA Astrophysics Data System (ADS)

Currier, R. M.

2017-12-01

In the McMurdo Dry Valleys of Antarctica, a Jurassic aged dolerite sill induced partial melting of granite in the shallow crust. The melt zone can be traced in full, from high degrees of melting (>60%) along the dolerite contact, to no apparent signs of melting, 10s of meters above the contact. Within this melt zone, the well-known rapakivi texture is found, arrested in various stages of development. High above the contact, and at low degrees of melting, K-feldspar crystals are slightly rounded and unmantled. In the lower half of the melt zone, mantles of cellular textured plagioclase appear on K-feldspar, and thicken towards the contact heat source. At the highest degrees of melting, cellular-textured plagioclase completely replaces restitic K-feldspar. Because of the complete exposure and intact context, the leading models of rapakivi texture formation can be tested against this system. The previously proposed mechanisms of subisothermal decompression, magma-mixing, and hydrothermal exsolution all fail to adequately describe rapakivi generation in this melt zone. Preferred here is a closed system model that invokes the production of a heterogeneous, disequilibrium melt through rapid heating, followed by calcium and sodium rich melt reacting in a peritectic fashion with restitic K-feldspar crystals. This peritectic reaction results in the production of plagioclase of andesine-oligoclase composition—which is consistent with not just mantles in the melt zone, but globally as well. The thickness of the mantle is diffusion limited, and thus a measure of the diffusive length scale of sodium and calcium over the time scale of melting. Thermal modeling provides a time scale of melting that is consistent with the thickness of observed mantles. Lastly, the distribution of mantled feldspars is highly ordered in this melt zone, but if it were mobilized and homogenized—mixing together cellular plagioclase, mantled feldspars, and unmantled feldspars—the result would be akin to rapakivi granites observed globally in Proterozoic systems. In essence, the melt zone is an embryonic rapakivi granite; not yet fully developed and displaying clear ties to its parental rock.

Drilling into a present-day migration pathway for hydrocarbons within a fault zone conduit in the Eugene Island 330 field, offshore Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, R.N.

1995-11-01

Within the Global Basins Research Network, we have developed 4-D seismic analysis techniques that, when integrated with pressure and temperature mapping, production history, geochemical monitoring, and finite element modeling, allow for the imaging of active fluid migration in the subsurface. We have imaged fluid flow pathways that are actively recharging shallower hydrocarbon reservoirs in the Eugene Island 330 field, offshore Louisiana. The hydrocarbons appear to be sourcing from turbidite stacks within the salt-withdrawal mini-basin buried deep within geopressure. Fault zone conduits provide transient migration pathways out of geopressure. To accomplish this 4-D imaging, we use multiple 3-D seismic surveys donemore » several years apart over the same blocks. 3-D volume processing and attribute analysis algorithms are used to identify significant seismic amplitude interconnectivity and changes over time that result from active fluid migration. Pressures and temperatures are then mapped and modeled to pro- vide rate and timing constraints for the fluid movement. Geochemical variability observed in the shallow reservoirs is attributed to the mixing of new with old oils. The Department of Energy has funded an industry cost-sharing project to drill into one of these active conduits in Eugene Island Block 330. Active fluid flow was encountered within the fault zone in the field demonstration experiment, and hydrocarbons were recovered. The active migration events connecting shallow reservoirs to deep sourcing regions imply that large, heretofore undiscovered hydrocarbon reserves exist deep within geopressures along the deep continental shelf of the northern Gulf of Mexico.« less

Characterizing hyporheic exchange processes using high-frequency electrical conductivity-discharge relationships on subhourly to interannual timescales

NASA Astrophysics Data System (ADS)

Singley, Joel G.; Wlostowski, Adam N.; Bergstrom, Anna J.; Sokol, Eric R.; Torrens, Christa L.; Jaros, Chris; Wilson, Colleen E.; Hendrickson, Patrick J.; Gooseff, Michael N.

2017-05-01

Concentration-discharge (C-Q) relationships are often used to quantify source water contributions and biogeochemical processes occurring within catchments, especially during discrete hydrological events. Yet, the interpretation of C-Q hysteresis is often confounded by complexity of the critical zone, such as numerous source waters and hydrochemical nonstationarity. Consequently, researchers must often ignore important runoff pathways and geochemical sources/sinks, especially the hyporheic zone because it lacks a distinct hydrochemical signature. Such simplifications limit efforts to identify processes responsible for the transience of C-Q hysteresis over time. To address these limitations, we leverage the hydrologic simplicity and long-term, high-frequency Q and electrical conductivity (EC) data from streams in the McMurdo Dry Valleys, Antarctica. In this two end-member system, EC can serve as a proxy for the concentration of solutes derived from the hyporheic zone. We utilize a novel approach to decompose loops into subhysteretic EC-Q dynamics to identify individual mechanisms governing hysteresis across a wide range of timescales. We find that hydrologic and hydraulic processes govern EC response to diel and seasonal Q variability and that the effects of hyporheic mixing processes on C-Q transience differ in short and long streams. We also observe that variable hyporheic turnover rates govern EC-Q patterns at daily to interannual timescales. Last, subhysteretic analysis reveals a period of interannual freshening of glacial meltwater streams related to the effects of unsteady flow on hyporheic exchange. The subhysteretic analysis framework we introduce may be applied more broadly to constrain the processes controlling C-Q transience and advance understanding of catchment evolution.

Reconciling Gases With Glasses: Magma Degassing, Overturn and Mixing at Kilauea Volcano, Hawai`i

NASA Astrophysics Data System (ADS)

Edmonds, M.; Gerlach, T. M.

2006-12-01

Our understanding of the volatile budget at Kilauea Volcano is based on measurements of the abundance of volatile elements in volcanic glasses and gases. Observations of volcanic gases gave rise to a fundamental model describing volatile fractionation between the summit and rift zone during the current eruption [Gerlach and Graeber, 1985]. Other workers' analysis of glasses from the Puna Ridge, Kilauea Iki and Pu`u `O`o indicate that magma degassing, drain-back, mixing and assimilation are important processes at Kilauea Volcano. Volcanic gases have not illustrated these kinds of processes clearly in the past, owing to infrequent and poorly resolved data. New, detailed studies of volcanic gas emissions have refined our understanding of volatile degassing and magma budgets at Kilauea Volcano. Open Path Fourier Transform Infra-Red spectroscopy measurements carried out during 2004-2005 allow retrieval of the relative abundances of the major volatile species H2O, CO2 and SO2, which together make up >99 vol% of the magmatic vapor phase. The proportions of these gases vary over time and space and can be used to infer magma transport, ascent, degassing, overturn and mixing and gas segregation processes within the plumbing system of Kilauea Volcano. Gases from Pu`u `O`o in 2004-2005 display a range in composition. A trend relates molar C/S to the total H2O content of the gases over time and space; total H2O ranges from 60-98 mol %, while molar C/S ranges from <0.01 to >50. The range in volcanic gas composition over time and space is caused by magma degassing, overturn and mixing of partially degassed magma with fresh primary magma beneath Pu`u `O`o. Measurements of the mean rate of magma degassing (from SO2 emissions) and mean lava effusion rate (from geophysical measurements of lava tube flux) suggest that a larger volume (DRE) of magma is degassing than is being erupted, on average. This analysis suggests that magma storage in the Rift Zone might be important during eruptions as well as between them; this has important implications for volcano monitoring. Application of this new, remote and accurate technique to measure volcanic gases allows data concerning the volatile budget, both from glasses and from gases, to be reconciled and used in tandem to provide more detailed and complete models for magma migration, storage and transport at Kilauea Volcano.

Plerixafor and Filgrastim For Mobilization of Donor Peripheral Blood Stem Cells Before A Donor Peripheral Blood Stem Cell Transplant in Treating Patients With Hematologic Malignancies

ClinicalTrials.gov

2017-06-26

Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Atypical Chronic Myeloid Leukemia, BCR-ABL Negative; Blastic Phase Chronic Myelogenous Leukemia; Chronic Phase Chronic Myelogenous Leukemia; de Novo Myelodysplastic Syndromes; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Burkitt Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Adult Lymphoblastic Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; Refractory Multiple Myeloma; Relapsing Chronic Myelogenous Leukemia; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndromes; Splenic Marginal Zone Lymphoma; Stage I Multiple Myeloma; Stage II Multiple Myeloma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Chronic Lymphocytic Leukemia; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Multiple Myeloma; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Chronic Lymphocytic Leukemia; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma

Potential for ground-water contamination from movement of wastewater through the unsaturated zone, upper Mojave River Basin, California

USGS Publications Warehouse

Umari, A.M.; Martin, P.M.; Schroeder, R.A.; Duell, L.F.; Fay, R.G.

1993-01-01

Septic-tank wastewater disposed in 30-foot-deep seepage pits (dry wells) at 46,000 residences is estimated to equal 18 percent of the natural recharge to the sole-source aquifer in the rapidly developing upper Mojave River Basin (Victor Valley) in the high desert northeast of Los Angeles. Vertical rates of movement of the wastewater wetting front through the unsaturated zone at three newly occupied residences ranged from 0.07 to 1.0 foot per day. These rates translate to traveltimes of several months to several years for the wastewater wetting front to reach the water table and imply that wastewater from many disposal systems already has reached the water table, which averages about 150 feet below land surface in the Victor Valley. As wastewater percolates from seepage pits into the adjacent unsaturated zone, the nitrogen present in reduced form is rapidly converted to nitrate. Analyses on soil-core extracts and soil moisturefrom suction lysimeters installed beneath the seepage pits at eight residences showed that nitrate concentrations and nitrate/ chloride ratios generally become lower with increasing depth. The intervals of greatest decline seemed to coincide with finer soil texture or were near the water table. Nitrate-reducing bacteria were tested for and found to be present in soil cores from two residences. Sparse nitrogen-15 data from suction lysimeters at one of these residences, where thenitrate concentration decreased by about one-half at a depth of 200 feet, indicate that the nitrate decline was accompanied by nitrogen-15 enrichment in the residual nitrate with an isotope-separation factor of about -10 permil. Despite the potential input of abundant nitrogen with the domestic wastewater recharge, nitrate concentrations in the area's ground water are generally low. The absence of high nitrate concentrations in the ground water is consistent with the existence of denitrification, a microbial nitrogen-removal mechanism, as wastewater moves through the thick unsaturated zone and mixes with the ground water. The observed low nitrate concentrations also could be explained by a dilution by vertical mixing in the saturated zone and retention of the wastewater in the unsaturated zone. Results of a single-cell mixing model that allows nitrate from wastewater to be mixedinstantaneously with the underlying ground water suggest that measurable increases in nitrate concentration should be expected within 5 to 10 years after wastewater reaches the water table if the mixing depth is less than 100 feet. Although high fecal-coliform densities were measured in wastewater from septic tanks and seepage pits, removal of these enteric bacteria in the unsaturated zone is very effective, as was indicated by their absence in soil only a few feet from the seepage pits. In testing for organic priority pollutants in wastewater, 17 of 85 compounds were detected. Most compounds detected were present in low concentrations, except at one residence where the concentration of three compounds exceeded 100 micrograms per liter. These high concentrations may be a consequence of disposal practices unique to this residence. Extractable organic priority pollutants were not found in any soil cores taken adjacent to seepage pits and, therefore, are not of concern.

Comparing Flow Mechanism Hypothesis with Mobility Data of Natural Tracers

NASA Astrophysics Data System (ADS)

Sanda, M.; Chárová, Z.; Zumr, D.; Císlerová, M.

2009-04-01

Hillslope rainfall-outflow interactions, groundwater fluxes and hydrological balance have been examined in the small mountainous headwater catchment Uhlířská (1.78 km2), Jizera Mountains, Czech Republic. The hillslope soil profile is formed by paleozolic crystalline bedrock overlaid by shallow highly permeable Cambisol, whereas the thick saturated glacial deposits in the valley are overlaid by Histosols. Quick communication of the vadose zone with the granite bedrock via preferential subsurface flowpaths is hypothesized, in agreement with the observation of instant water transformation through the permeable Cambisols, to outflow caused by storms. There is regularly a quick response of high magnitude, although surface runoff occurs very rarely. Standard climatic and hydrological monitoring is supplemented by measurements of the soil moisture, soil pore water suction, hillslope stormflow in the vadose zone and water table fluctuation in the saturated subsurface. Water sampling for analysis of the isotopes 18O and 2H and geochemical tracer silica in the form of SiO2 is performed throughout the catchment. The episode based isotopic data serve for the separation of the particular components of the outflow hydrograph and for the determination of the contribution of event and pre-event water in the hypodermic hillslope outflow and in the catchment outflow as a whole. Variation of silica content in the water cycle components was examined to assess contributions from the soil profile and the aquifer. Significant portion of event catchment runoff was assigned to pre-event water, partly stored in the shallow soil layers on hillslopes and partly in the valley aquifer. Here, a significant mixing (in form of attenuation of the input signal of 18O or 2H measured for precipitation) occurs as proven by sampling and modeling by means of physically based models for vadose and saturated zones. Hydrological balance of the catchment shows only minor discrepancies in averaged value of the either isotope in the whole balanced mass on the input (precipitation) and the output (streamflow). There is a strong mixing of water already in the root zone, where transpiration takes place. Preferential flow in the soil profile proved to be a major transporting mechanism for water in the form of quick subsurface runoff. The hypothesis that the hillslope soil layers controls the distribution of the flow into the groundwater recharge and/or the shallow subsurface flow during the rainfall-runoff episode, was confirmed. Porous structures of the catchment play dominant role in initial mixing of the water. We want to acknowledge projects GACR 205/09/0831 and 205/08/1174 of the Grant Agency of the Czech Republic for support of this contribution.

Linking optical properties of dissolved organic matter to multiple processes at the coastal plume zone in the East China Sea.

PubMed

Jiang, Yulin; Zhao, Jianfu; Li, Penghui; Huang, Qinghui

2016-10-12

Because of the significance in photosynthesis, nutrient dynamics, trophodynamics and biological activity, dissolved organic matter (DOM) is important to the microbial community in the coastal plume zone. In this study, we investigated the hydrodynamic processes, photodegradation and biodegradation of DOM at the Yangtze River plume in the East China Sea through analyzing water quality and optical properties of DOM. Surface water samples were collected to examine water quality and fluorescence properties of fluorescent dissolved organic matter (FDOM). The results indicated that dilution was the key factor in the multiple processes, and the mixing process gradually increased from nearshore to offshore in coastal water. Four components of FDOM representing humic-like substances (C1 & C4) and protein-like substances (C2 & C3) were identified, and all components showed nearly conservative behaviors. Protein-like substances were more mutable compared to humic-like substances. The photodegradation of humic-like substances caused brown algae blooms to some extent. The molecular weight of humic substances gradually decreased along the mixing process. FDOM in the plume zone was both of terrigenous and autochthonous origins, and the characteristic of terrigenous origin was obvious compared to that of autochthonous origin.

Coupled Spatiotemporal Dynamics of Microbial Community Ecology, Biogeochemistry, and Hydrologic Mixing

NASA Astrophysics Data System (ADS)

Stegen, J.; Johnson, T. C.; Fredrickson, J.; Wilkins, M.; Konopka, A.; Nelson, W.; Arntzen, E.; Chrisler, W.; Chu, R. K.; Fansler, S.; Kennedy, D.; Resch, T.; Tfaily, M. M.

2015-12-01

The hyporheic zone (HZ) is a critical ecosystem component that links terrestrial, surface water, and groundwater ecosystems. A dominant feature of the HZ is groundwater-surface water mixing and the input of terrestrially—as well as aquatically—derived organic carbon. In many systems the HZ has a relatively small spatial extent, but in larger riverine systems groundwater-surface water mixing can occur 100s of meters beyond the surface water shoreline; we consider these more distal locations to be within the 'subsurface interaction zone' (SIZ) as they are beyond the traditional HZ. Microbial communities in the HZ and SIZ drive biogeochemical processes in these system components, yet relatively little is known about the ecological processes that drive HZ and SIZ microbial communities. Here, we applied ecological theory, aqueous biogeochemistry, DNA sequencing, and ultra-high resolution organic carbon profiling to field samples collected through space (400m spatial extent) and time (7 month temporal extent) within the Hanford Site 300 Area. These data streams were integrated to evaluate how the influence of groundwater-surface water mixing on microbial communities changes when moving from the HZ to the broader SIZ. Our results indicate that groundwater-surface water mixing (i) consistently stimulated heterotrophic respiration, but only above a threshold of surface water intrusion, (ii) did not stimulate denitrification, (iii) caused deterministic shifts in HZ microbial communities due to changes in organic carbon composition, and (iv) did not cause shifts in SIZ microbial communities. These results suggest that microbial communities and the biogeochemical processes they drive are impacted by groundwater-surface water mixing primarily in the HZ and to a lesser extent in the SIZ.

Fluid mixing and the deep biosphere of a fossil Lost City-type hydrothermal system at the Iberia Margin.

PubMed

Klein, Frieder; Humphris, Susan E; Guo, Weifu; Schubotz, Florence; Schwarzenbach, Esther M; Orsi, William D

2015-09-29

Subseafloor mixing of reduced hydrothermal fluids with seawater is believed to provide the energy and substrates needed to support deep chemolithoautotrophic life in the hydrated oceanic mantle (i.e., serpentinite). However, geosphere-biosphere interactions in serpentinite-hosted subseafloor mixing zones remain poorly constrained. Here we examine fossil microbial communities and fluid mixing processes in the subseafloor of a Cretaceous Lost City-type hydrothermal system at the magma-poor passive Iberia Margin (Ocean Drilling Program Leg 149, Hole 897D). Brucite-calcite mineral assemblages precipitated from mixed fluids ca. 65 m below the Cretaceous paleo-seafloor at temperatures of 31.7 ± 4.3 °C within steep chemical gradients between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing hydrothermal fluid at moderate temperatures created conditions capable of supporting microbial activity. Dense microbial colonies are fossilized in brucite-calcite veins that are strongly enriched in organic carbon (up to 0.5 wt.% of the total carbon) but depleted in (13)C (δ(13)C(TOC) = -19.4‰). We detected a combination of bacterial diether lipid biomarkers, archaeol, and archaeal tetraethers analogous to those found in carbonate chimneys at the active Lost City hydrothermal field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin, possibly before the onset of seafloor spreading. Lost City-type serpentinization systems have been discovered at midocean ridges, in forearc settings of subduction zones, and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments.

Fluid mixing and the deep biosphere of a fossil Lost City-type hydrothermal system at the Iberia Margin

PubMed Central

Klein, Frieder; Humphris, Susan E.; Guo, Weifu; Schubotz, Florence; Schwarzenbach, Esther M.; Orsi, William D.

2015-01-01

Subseafloor mixing of reduced hydrothermal fluids with seawater is believed to provide the energy and substrates needed to support deep chemolithoautotrophic life in the hydrated oceanic mantle (i.e., serpentinite). However, geosphere-biosphere interactions in serpentinite-hosted subseafloor mixing zones remain poorly constrained. Here we examine fossil microbial communities and fluid mixing processes in the subseafloor of a Cretaceous Lost City-type hydrothermal system at the magma-poor passive Iberia Margin (Ocean Drilling Program Leg 149, Hole 897D). Brucite−calcite mineral assemblages precipitated from mixed fluids ca. 65 m below the Cretaceous paleo-seafloor at temperatures of 31.7 ± 4.3 °C within steep chemical gradients between weathered, carbonate-rich serpentinite breccia and serpentinite. Mixing of oxidized seawater and strongly reducing hydrothermal fluid at moderate temperatures created conditions capable of supporting microbial activity. Dense microbial colonies are fossilized in brucite−calcite veins that are strongly enriched in organic carbon (up to 0.5 wt.% of the total carbon) but depleted in 13C (δ13CTOC = −19.4‰). We detected a combination of bacterial diether lipid biomarkers, archaeol, and archaeal tetraethers analogous to those found in carbonate chimneys at the active Lost City hydrothermal field. The exposure of mantle rocks to seawater during the breakup of Pangaea fueled chemolithoautotrophic microbial communities at the Iberia Margin, possibly before the onset of seafloor spreading. Lost City-type serpentinization systems have been discovered at midocean ridges, in forearc settings of subduction zones, and at continental margins. It appears that, wherever they occur, they can support microbial life, even in deep subseafloor environments. PMID:26324888

The role of tributary mixing in chemical variations at a karst spring, Milandre, Switzerland

NASA Astrophysics Data System (ADS)

Perrin, J.; Jeannin, P.-Y.; Cornaton, F.

2007-01-01

SummarySolute concentration variations during flood events were investigated in a karst aquifer of the Swiss Jura. Observations were made at the spring, and at the three main subterraneous tributaries feeding the spring. A simple transient flow and transport numerical model was able to reproduce chemographs and hydrographs observed at the spring, as a result of a mixing of the concentration and discharge of the respective tributaries. Sensitivity analysis carried out with the model showed that it is possible to produce chemical variations at the spring even if all tributaries have constant (but different for each of them) solute concentrations. This process is called tributary mixing. The good match between observed and modelled curves indicate that, in the phreatic zone, tributary mixing is probably an important process that shapes spring chemographs. Chemical reactions and other mixing components (e.g. from low permeability volumes) have a limited influence. Dissolution-related (calcium, bicarbonate, specific conductance) and pollution-related parameters (nitrate, chloride, potassium) displayed slightly different behaviours: during moderate flood events, the former showed limited variations compared to the latter. During large flood events, both presented chemographs with significant changes. No significant event water participates in moderate flood events and tributary mixing will be the major process shaping chemographs. Variations are greater for parameters with higher spatial variability (e.g. pollution-related). Whereas for large flood events, the contribution of event water becomes significant and influences the chemographs of all the parameters. As a result, spring water vulnerability to an accidental pollution is low during moderate flood events and under base flow conditions. It strongly increases during large flood events, because event water contributes to the spring discharge.

Magmatic inclusions in rhyolites, contaminated basalts, and compositional zonation beneath the Coso volcanic field, California

USGS Publications Warehouse

Bacon, C.R.; Metz, J.

1984-01-01

Basaltic lava flows and high-silica rhyolite domes form the Pleistocene part of the Coso volcanic field in southeastern California. The distribution of vents maps the areal zonation inferred for the upper parts of the Coso magmatic system. Subalkalic basalts (<50% SiO2) were erupted well away from the rhyolite field at any given time. Compositional variation among these basalts can be ascribed to crystal fractionation. Erupted volumes of these basalts decrease with increasing differentiation. Mafic lavas containing up to 58% SiO2, erupted adjacent to the rhyolite field, formed by mixing of basaltic and silicic magma. Basaltic magma interacted with crustal rocks to form other SiO2-rich mafic lavas erupted near the Sierra Nevada fault zone. Several rhyolite domes in the Coso volcanic field contain sparse andesitic inclusions (55-61% SiO2). Pillow-like forms, intricate commingling and local diffusive mixing of andesite and rhyolite at contacts, concentric vesicle distribution, and crystal morphologies indicative of undercooling show that inclusions were incorporated in their rhyolitic hosts as blobs of magma. Inclusions were probably dispersed throughout small volumes of rhyolitic magma by convective (mechanical) mixing. Inclusion magma was formed by mixing (hybridization) at the interface between basaltic and rhyolitic magmas that coexisted in vertically zoned igneous systems. Relict phenocrysts and the bulk compositions of inclusions suggest that silicic endmembers were less differentiated than erupted high-silica rhyolite. Changes in inferred endmembers of magma mixtures with time suggest that the steepness of chemical gradients near the silicic/mafic interface in the zoned reservoir may have decreased as the system matured, although a high-silica rhyolitic cap persisted. The Coso example is an extreme case of large thermal and compositional contrast between inclusion and host magmas; lesser differences between intermediate composition magmas and inclusions lead to undercooling phenomena that suggest smaller ??T. Vertical compositional zonation in magma chambers has been documented through study of products of voluminous pyroclastic eruptions. Magmatic inclusions in volcanic rocks provide evidence for compositional zonation and mixing processes in igneous systems when only lava is erupted. ?? 1984 Springer-Verlag.

Dolomitization in a mixing zone of near-seawater composition, Late Pleistocene, northeastern Yucatan Peninsula

USGS Publications Warehouse

Ward, W. C.; Halley, Robert B.

1985-01-01

18O compositions of Yucatecan dolomite and of modern ground water suggest dolomite precipitation from mixed water ranging from about 75% seawater, 25% freshwater to nearly all seawater. (Isotope analyses are for the most stable calcian dolomites; more soluble, calcium-rich dolomite presumably is analyzed with calcite and thought to be isotopically lighter than the less soluble dolomite.) In the cement sequence, the most stable dolomite is followed by more soluble dolomite as ground water becomes less saline. Isotope analyses, together with position of dolomite in the cement sequence, suggest the most stable calcian dolomite (including limpid dolomite) precipitated from mixed water with large proportions of seawater, and the less stable, more calcian dolomite precipitated from fresher mixed water.

Mixing geometric and radiometric features for change classification

NASA Astrophysics Data System (ADS)

Fournier, Alexandre; Descombes, Xavier; Zerubia, Josiane

2008-02-01

Most basic change detection algorithms use a pixel-based approach. Whereas such approach is quite well defined for monitoring important area changes (such as urban growth monitoring) in low resolution images, an object based approach seems more relevant when the change detection is specifically aimed toward targets (such as small buildings and vehicles). In this paper, we present an approach that mixes radiometric and geometric features to qualify the changed zones. The goal is to establish bounds (appearance, disappearance, substitution ...) between the detected changes and the underlying objects. We proceed by first clustering the change map (containing each pixel bitemporal radiosity) in different classes using the entropy-kmeans algorithm. Assuming that most man-made objects have a polygonal shape, a polygonal approximation algorithm is then used in order to characterize the resulting zone shapes. Hence allowing us to refine the primary rough classification, by integrating the polygon orientations in the state space. Tests are currently conducted on Quickbird data.

Nearshore dynamics of artificial sand and oil agglomerates

USGS Publications Warehouse

Dalyander, P. Soupy; Plant, Nathaniel G.; Long, Joseph W.; McLaughlin, Molly R.

2015-01-01

Weathered oil can mix with sediment to form heavier-than-water sand and oil agglomerates (SOAs) that can cause beach re-oiling for years after a spill. Few studies have focused on the physical dynamics of SOAs. In this study, artificial SOAs (aSOAs) were created and deployed in the nearshore, and shear stress-based mobility formulations were assessed to predict SOA response. Prediction sensitivity to uncertainty in hydrodynamic conditions and shear stress parameterizations were explored. Critical stress estimates accounting for large particle exposure in a mixed bed gave the best predictions of mobility under shoaling and breaking waves. In the surf zone, the 10-cm aSOA was immobile and began to bury in the seafloor while smaller size classes dispersed alongshore. aSOAs up to 5 cm in diameter were frequently mobilized in the swash zone. The uncertainty in predicting aSOA dynamics reflects a broader uncertainty in applying mobility and transport formulations to cm-sized particles.

Estimation of uncertainty in tracer gas measurement of air change rates.

PubMed

Iizuka, Atsushi; Okuizumi, Yumiko; Yanagisawa, Yukio

2010-12-01

Simple and economical measurement of air change rates can be achieved with a passive-type tracer gas doser and sampler. However, this is made more complex by the fact many buildings are not a single fully mixed zone. This means many measurements are required to obtain information on ventilation conditions. In this study, we evaluated the uncertainty of tracer gas measurement of air change rate in n completely mixed zones. A single measurement with one tracer gas could be used to simply estimate the air change rate when n = 2. Accurate air change rates could not be obtained for n ≥ 2 due to a lack of information. However, the proposed method can be used to estimate an air change rate with an accuracy of <33%. Using this method, overestimation of air change rate can be avoided. The proposed estimation method will be useful in practical ventilation measurements.

System and method for generating micro-seismic events and characterizing properties of a medium with non-linear acoustic interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vu, Cung Khac; Nihei, Kurt; Johnson, Paul A.

2015-12-29

A method and system includes generating a first coded acoustic signal including pulses each having a modulated signal at a central frequency; and a second coded acoustic signal each pulse of which includes a modulated signal a central frequency of which is a fraction d of the central frequency of the modulated signal for the corresponding pulse in the first plurality of pulses. A receiver detects a third signal generated by a non-linear mixing process in the mixing zone and the signal is processed to extract the third signal to obtain an emulated micro-seismic event signal occurring at the mixingmore » zone; and to characterize properties of the medium or creating a 3D image of the properties of the medium, or both, based on the emulated micro-seismic event signal.« less

Exploring the Inner Edge of the Habitable Zone with Fully Coupled Oceans

NASA Technical Reports Server (NTRS)

Way, M.J; Del Genio, A.D.; Kelley, M.; Aleinov, I.; Clune, T.

2015-01-01

The role of rotation in planetary atmospheres plays an important role in regulating atmospheric and oceanic heat flow, cloud formation and precipitation. Using the Goddard Institute for Space Studies (GISS) three dimension General Circulation Model (3D-GCM) we demonstrate how varying rotation rate and increasing the incident solar flux on a planet are related to each other and may allow the inner edge of the habitable zone to be much closer than many previous habitable zone studies have indicated. This is shown in particular for fully coupled ocean runs -- some of the first that have been utilized in this context. Results with a 100m mixed layer depth and our fully coupled ocean runs are compared with those of Yang et al. 2014, which demonstrates consistency across models. However, there are clear differences for rotations rates of 1-16x present earth day lengths between the mixed layer and fully couple ocean models, which points to the necessity of using fully coupled oceans whenever possible. The latter was recently demonstrated quite clearly by Hu & Yang 2014 in their aquaworld study with a fully coupled ocean when compared with similar mixed layer ocean studies and by Cullum et al. 2014. Atmospheric constituent amounts were also varied alongside adjustments to cloud parameterizations (results not shown here). While the latter have an effect on what a planet's global mean temperature is once the oceans reach equilibrium they do not qualitatively change the overall relationship between the globally averaged surface temperature and incident solar flux for rotation rates ranging from 1 to 256 times the present Earth day length. At the same time this study demonstrates that given the lack of knowledge about the atmospheric constituents and clouds on exoplanets there is still a large uncertainty as to where a planet will sit in a given star's habitable zone.

Coupled Hf-Nd-Pb isotope co-variations of HIMU oceanic island basalts from Mangaia, Cook-Austral islands, suggest an Archean source component in the mantle transition zone

NASA Astrophysics Data System (ADS)

Nebel, Oliver; Arculus, Richard J.; van Westrenen, Wim; Woodhead, Jon D.; Jenner, Frances E.; Nebel-Jacobsen, Yona J.; Wille, Martin; Eggins, Stephen M.

2013-07-01

Although it is widely accepted that oceanic island basalts (OIB) sample geochemically distinct mantle reservoirs including recycled oceanic crust, the composition, age, and locus of these reservoirs remain uncertain. OIB with highly radiogenic Pb isotope signatures are grouped as HIMU (high-μ, with μ = 238U/204Pb), and exhibit unique Hf-Nd isotopic characteristics, defined as ΔɛHf, deviant from a terrestrial igneous rock array that includes all other OIB types. Here we combine new Hf isotope data with previous Nd-Pb isotope measurements to assess the coupled, time-integrated Hf-Nd-Pb isotope evolution of the most extreme HIMU location (Mangaia, French Polynesia). In comparison with global MORB and other OIB types, Mangaia samples define a unique trend in coupled Hf-Nd-Pb isotope co-variations (expressed in 207Pb/206Pb vs. ΔɛHf). In a model employing subducted, dehydrated oceanic crust, mixing between present-day depleted MORB mantle (DMM) and small proportions (˜5%) of a HIMU mantle endmember can re-produce the Hf-Nd-Pb isotope systematics of global HIMU basalts (sensu stricto; i.e., without EM-1/EM-2/FOZO components). An age range of 3.5 to <2 Ga is required for HIMU endmember(s) that mix with DMM to account for the observed present-day HIMU isotope compositions, suggesting a range of age distributions rather than a single component in the mantle. Our data suggest that mixing of HIMU mantle endmembers and DMM occurs in the mantle transition zone by entrainment in secondary plumes that rise at the edge of the Pacific Large Low Seismic Velocity Zone (LLSVP). These create either pure HIMU (sensu stricto) or HIMU affected by other enriched mantle endmembers (sensu lato). If correct, this requires isolation of parts of the mantle transition zone for >3 Gyr and implies that OIB chemistry can be used to test geodynamic models.

Calibrating damping rates with LEGACY linewidths

NASA Astrophysics Data System (ADS)

Houdek, Günter

2017-10-01

Linear damping rates of radial oscillation modes in selected Kepler stars are estimated with the help of a nonadiabatic stability analysis. The convective fluxes are obtained from a nonlocal, time-dependent convection model. The mixing-length parameter is calibrated to the surface-convection-zone depth of a stellar model obtained from fitting adiabatic frequencies to the LEGACY* observations, and two of the three nonlocal convection parameters are calibrated to the corresponding LEGACY* linewidth measurements. The atmospheric structure in the 1D stability analysis adopts a temperature-optical-depth relation derived from 3D hydrodynamical simulations. Results from 3D simulations are also used to calibrate the turbulent pressure and to guide the functional form of the depth-dependence of the anisotropy of the turbulent velocity field in the 1D stability computations.

Spatial distribution, enrichment, and source of environmentally important elements in Batticaloa lagoon, Sri Lanka.

PubMed

Adikaram, Madurya; Pitawala, Amarasooriya; Ishiga, Hiroaki; Jayawardana, Daham

2017-01-01

The present paper is the first documentation of distribution and contamination status of environmentally important elements of superficial sediments in the Batticaloa lagoon that is connected to the largest bay of the world. Surface sediment samples were collected from 34 sites covering all over the lagoon. Concentrations of elements such as As, Cr, Cu, Fe, Nb, Ni, Pb, Sc, Sr, Th, V, Y, Zn, and Zr were measured by X-ray florescence analysis. Geochemically, the lagoon has three different zones that were influenced mainly by fresh water sources, marine fronts, and intermediate mixing zones. The marine sediment quality standards indicate that Zr and Th values are exceeded throughout the lagoon. According to the freshwater sediment quality standards, Cr levels of all sampling sites exceed the threshold effect level (TEL) and 17 % of them are even above the probable effect level (PEL). Most sampling sites of the channel discharging areas show minor enrichment of Cu, Ni, and Zn with respect to the TEL. Contamination indices show that the lagoon mouth area is enriched with As. Statistical analysis implies that discharges from agricultural channel and marine fluxes of the lagoon effects on the spatial distribution of measured elements. Further research is required to understand the rate of contamination in the studied marine system.

Assessing dissolved carbon transport and transformation along an estuarine river with stable isotope analyses

NASA Astrophysics Data System (ADS)

He, Songjie; Xu, Y. Jun

2017-10-01

Estuaries play an important role in the dynamics of dissolved carbon from rivers to coastal oceans. However, our knowledge of dissolved carbon transport and transformation in mixing zones of the world's coastal rivers is still limited. This study aims to determine how dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations and stable isotopes (δ13CDIC and δ13CDOC) change along an 88-km long estuarine river, the Calcasieu River in Louisiana, southern USA, with salinity ranging from 0.02 to 21.92. The study is expected to elucidate which processes most likely control carbon dynamics in a freshwater-saltwater mixing system, and to evaluate the net metabolism of this estuary. Between May 2015 and February 2016, water samples were collected and in-situ measurements on ambient water conditions were performed during five field trips at six sites from upstream to downstream of the Calcasieu River, which enters the Northern Gulf of Mexico (NGOM). The DIC concentration and δ13CDIC increased rapidly with increasing salinity in the mixing zone. The average DIC concentration and δ13CDIC at the site closest to the NGOM (site 6) were 1.31 mM and -6.34‰, respectively, much higher than those at the site furthest upstream (site 1, 0.42 mM and -20.83‰). The DIC concentrations appeared to be largely influenced by conservative mixing, while high water temperature may have played a role in deviating DIC concentration from the conservative line due likely to increased respiration and decomposition. The δ13CDIC values were close to those suggested by the conservative mixing model for May, June and November, but lower than those for July and February, suggesting that an estuarine river can fluctuate from a balanced to a heterotrophic system (i.e., production/respiration (P/R) < 1) seasonally. Unlike the DIC longitudinal trend, the DOC concentrations in the river estuary decreased from upstream to downstream, but to a much smaller degree. The DOC concentrations consistently showed a deviation from those suggested by the conservative mixing model, which may have been a consequence of in-stream photosynthesis. This river estuary consistently showed depleted δ13CDOC values (i.e., from -30.56‰ to -25.92‰), suggesting that the DOC source in the mixing zone was highly terrestrially derived. However, in this relatively small isotopic range, δ13CDOC alone has limitations in differentiating carbon produced by aquatic photosynthesis from carbon produced by terrestrial photosynthesis in a river-ocean continuum.

Provider payment methods and health worker motivation in community-based health insurance: a mixed-methods study.

PubMed

Robyn, Paul Jacob; Bärnighausen, Till; Souares, Aurélia; Traoré, Adama; Bicaba, Brice; Sié, Ali; Sauerborn, Rainer

2014-05-01

In a community-based health insurance (CBHI) introduced in 2004 in Nouna health district, Burkina Faso, poor perceived quality of care by CBHI enrollees has been a key factor in observed high drop-out rates. The poor quality perceptions have been previously attributed to health worker dissatisfaction with the provider payment method used by the scheme and the resulting financial risk of health centers. This study applied a mixed-methods approach to investigate how health workers working in facilities contracted by the CBHI view the methods of provider payment used by the CBHI. In order to analyze these relationships, we conducted 23 in-depth interviews and a quantitative survey with 98 health workers working in the CBHI intervention zone. The qualitative in-depth interviews identified that insufficient levels of capitation payments, the infrequent schedule of capitation payment, and lack of a payment mechanism for reimbursing service fees were perceived as significant sources of health worker dissatisfaction and loss of work-related motivation. Combining qualitative interview and quantitative survey data in a mixed-methods analysis, this study identified that the declining quality of care due to the CBHI provider payment method was a source of significant professional stress and role strain for health workers. Health workers felt that the following five changes due to the provider payment methods introduced by the CBHI impeded their ability to fulfill professional roles and responsibilities: (i) increased financial volatility of health facilities, (ii) dissatisfaction with eligible costs to be covered by capitation; (iii) increased pharmacy stock-outs; (iv) limited financial and material support from the CBHI; and (v) the lack of mechanisms to increase provider motivation to support the CBHI. To address these challenges and improve CBHI uptake and health outcomes in the targeted populations, the health care financing and delivery model in the study zone should be reformed. We discuss concrete options for reform based on the study findings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of mixed-host organic light emitting diodes

NASA Astrophysics Data System (ADS)

Yeh Yee, Kee

One of the limiting factors to the OLED stability or lifetime is the charge buildup at the bilayer heterojunction (HJ) between the hole transport layer (HTL) and electron transport layer (ETL). In recent years, this abrupt interface has been moderated by mixing HTL and ETL to form a single mixed-host, light emitting layer. For uniformly mixed-host (UM) OLED, the device lifetime and also the efficiency were improved due to the spatial broadening of the recombination zone. Similar device architectures, such as the step-wise graded mixed-host (SGM-OLED) and the continuously graded mixed-host (CGM-OLED) have also been implemented by a number of researchers. In this work, a premix of hole transport material (HTM) and electron transport material (ETM), namely TPD and Alq, is prepared for one-step thermal evaporation of the mixed-host light emitting layer (EML). Depending on the evaporation rate, the CGM-OLEDs with different concentration profiles of HTM and ETM in the EML are obtained, which are inversely proportional to each other.

Mixing and reactions in multiphase flow through porous media

NASA Astrophysics Data System (ADS)

Jimenez-Martinez, J.; Le Borgne, T.; Meheust, Y.; Porter, M. L.; De Anna, P.; Hyman, J.; Tabuteau, H.; Turuban, R.; Carey, J. W.; Viswanathan, H. S.

2016-12-01

The understanding and quantification of flow and transport processes in multiphase systems remains a grand scientific and engineering challenge in natural and industrial systems (e.g., soils and vadose zone, CO2 sequestration, unconventional oil and gas extraction, enhanced oil recovery). Beyond the kinetic of the chemical reactions, mixing processes in porous media play a key role in controlling both fluid-fluid and fluid-solid reactions. However, conventional continuum-scale models and theories oversimplify and/or ignore many important pore-scale processes. Multiphase flows, with the creation of highly heterogeneous fluid velocity fields (i.e., low velocities regions or stagnation zones, and high velocity regions or preferential paths), makes conservative and reactive transport more complex. We present recent multi-scale experimental developments and theoretical approaches to quantify transport, mixing, and reaction and their coupling with multiphase flows. We discuss our main findings: i) the sustained concentration gradients and enhanced reactivity in a two-phase system for a continuous injection, and the comparison with a pulse line injection; ii) the enhanced mixing by a third mobile-immiscible phase; and iii) the role that capillary forces play in the localization of the fluid-solid reactions. These experimental results are for highly-idealized geometries, however, the proposed models are related to basic porous media and unsaturated flow properties, and could be tested on more complex systems.

CPI-613, Bendamustine Hydrochloride, and Rituximab in Treating Patients With Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma

ClinicalTrials.gov

2017-05-25

B-cell Adult Acute Lymphoblastic Leukemia; B-cell Chronic Lymphocytic Leukemia; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Testicular Lymphoma; Waldenström Macroglobulinemia

Primary zone dynamics in a gas turbine combustor

NASA Technical Reports Server (NTRS)

Sullivan, J. P.; Barron, D.; Seal, M.; Morgan, D.; Murthy, S. N. B.

1989-01-01

Fluid mechanical investigations simulating the flow in the primary zone of a gas turbine combustor are presented using three generic test rigs: (1) rotating pipe yielding a swirling jet of air; (2) primary zone model with a single swirler and various primary jet configurations, operated with air; and (3) two rectangular models of a (stretched-out) annular combustor with five swirlers in the backwall and with various primary jet configurations, one operated with air and the other with water. Concentration measurements are obtained using laser sheet imaging techniques and velocity measurements using a laser Doppler velocimeter. The results show recirculation zones, intense mixing, instabilities of the interacting jets and the presence of large random vortical motions. The flowfields are shown to exhibit bimodal behavior, have asymmetries despite symmetrical geometry and inlet conditions and display strong jet/swirler and swirler/swirler interactions.

Hydrogenation of carbonaceous materials

DOEpatents

Friedman, Joseph; Oberg, Carl L.; Russell, Larry H.

1980-01-01

A method for reacting pulverized coal with heated hydrogen-rich gas to form hydrocarbon liquids suitable for conversion to fuels wherein the reaction involves injection of pulverized coal entrained in a minimum amount of gas and mixing the entrained coal at ambient temperature with a separate source of heated hydrogen. In accordance with the present invention, the hydrogen is heated by reacting a small portion of the hydrogen-rich gas with oxygen in a first reaction zone to form a gas stream having a temperature in excess of about 1000.degree. C. and comprising a major amount of hydrogen and a minor amount of water vapor. The coal particles then are reacted with the hydrogen in a second reaction zone downstream of the first reaction zone. The products of reaction may be rapidly quenched as they exit the second reaction zone and are subsequently collected.

Experimental study of stratified jet by simultaneous measurements of velocity and density fields

NASA Astrophysics Data System (ADS)

Xu, Duo; Chen, Jun

2012-07-01

Stratified flows with small density difference commonly exist in geophysical and engineering applications, which often involve interaction of turbulence and buoyancy effect. A combined particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) system is developed to measure the velocity and density fields in a dense jet discharged horizontally into a tank filled with light fluid. The illumination of PIV particles and excitation of PLIF dye are achieved by a dual-head pulsed Nd:YAG laser and two CCD cameras with a set of optical filters. The procedure for matching refractive indexes of two fluids and calibration of the combined system are presented, as well as a quantitative analysis of the measurement uncertainties. The flow structures and mixing dynamics within the central vertical plane are studied by examining the averaged parameters, turbulent kinetic energy budget, and modeling of momentum flux and buoyancy flux. At downstream, profiles of velocity and density display strong asymmetry with respect to its center. This is attributed to the fact that stable stratification reduces mixing and unstable stratification enhances mixing. In stable stratification region, most of turbulence production is consumed by mean-flow convection, whereas in unstable stratification region, turbulence production is nearly balanced by viscous dissipation. Experimental data also indicate that at downstream locations, mixing length model performs better in mixing zone of stable stratification regions, whereas in other regions, eddy viscosity/diffusivity models with static model coefficients represent effectively momentum and buoyancy flux terms. The measured turbulent Prandtl number displays strong spatial variation in the stratified jet.

Optimization of Orifice Geometry for Cross-Flow Mixing in a Cylindrical Duct

NASA Technical Reports Server (NTRS)

Sowa, W. A.; Kroll, J. T.; Samuelsen, G. S.; Holdeman, J. D.

1994-01-01

Mixing of gaseous jets in a cross-flow has significant applications in engineering, one example of which is the dilution zone of a gas turbine combustor. Despite years of study, the design of jet injection in combustors is largely based on practical experience. A series of experiments was undertaken to delineate the optimal mixer orifice geometry. A cross-flow to core-flow momentum-flux ratio of 40 and a mass flow ratio of 2.5 were selected as representative of an advanced design. An experimental test matrix was designed around three variables: the number of orifices, the orifice aspect ratio (long-to-short dimension), and the orifice angle. A regression analysis was performed on the data to arrive at an interpolating equation that predicted the mixing performance of orifice geometry combinations within the range of the test matrix parameters. Results indicate that mixture uniformity is a non-linear function of the number of orifices, the orifice aspect ratio, and the orifice angle. Optimum mixing occurs when the asymptotic mean jet trajectories are in the range of 0.35 less than r/R less than 0.5 (where r = 0 is at the mixer wall) at z/R = 1.0. At the optimum number of orifices, the difference between shallow-angled slots with large aspect ratios and round holes is minimal and either approach will lead to good mixing performance. At the optimum number of orifices, it appears possible to have two local optimums where one corresponds to an aspect ratio of 1.0 and the other to a high aspect ratio.

The in vivo performance of a novel thermal accelerant agent used for augmentation of microwave energy delivery within biologic tissues during image-guided thermal ablation: a porcine study.

PubMed

Park, William Keun Chan; Maxwell, Aaron Wilhelm Palmer; Frank, Victoria Elizabeth; Primmer, Michael Patrick; Paul, Jarod Brian; Collins, Scott Andrew; Lombardo, Kara Anne; Lu, Shaolei; Borjeson, Tiffany Marie; Baird, Grayson Luderman; Dupuy, Damian Edward

2018-02-01

To investigate the effects of a novel caesium-based thermal accelerant (TA) agent on ablation zone volumes following in vivo microwave ablation of porcine liver and skeletal muscle, and to correlate the effects of TA with target organ perfusion. This prospective study was performed following institutional animal care and use committee approval. Microwave ablation was performed in liver and resting skeletal muscle in eight Sus scrofa domesticus swine following administration of TA at concentrations of 0 mg/mL (control), 100 mg/mL and 250 mg/mL. Treated tissues were explanted and stained with triphenyltetrazolium chloride (TTC) for quantification of ablation zone volumes, which were compared between TA and control conditions. Hematoxylin and eosin (H&E) staining was also performed for histologic analysis. General mixed modelling with a log-normal distribution was used for all quantitative comparisons (p = 0.05). A total of 28 ablations were performed in the liver and 18 in the skeletal muscle. The use of TA significantly increased ablation zone volumes in a dose-dependent manner in both the porcine muscle and liver (p < 0.01). Both the absolute mean ablation zone volume and percentage increase in ablation zone volume were greater in the resting skeletal muscle than in the liver. In one swine, a qualitative mitigation of heat sink effects was observed by TTC and H&E staining. Non-lethal polymorphic ventricular tachycardia was identified in one swine, treated with intravenous amiodarone. The use of a novel TA agent significantly increased mean ablation zone volumes following microwave ablation using a porcine model. The relationship between TA administration and ablation size was dose-dependent and inversely proportional to the degree of target organ perfusion, and a qualitative reduction in heat-sink effects was observed.

Frictional behavior of carbonate-rich sediments in subduction zones

NASA Astrophysics Data System (ADS)

Rabinowitz, H. S.; Savage, H. M.; Carpenter, B. M.; Collettini, C.

2016-12-01

Deformation in rocks and sediments is controlled by multiple mechanisms, each governed by its own pressure- (P), temperature- (T), and slip velocity- (v) dependent kinetics. Frictional behavior depends on which of these mechanisms are dominant, and, thus, varies with P, T, and v. Carbonates are a useful material with which to interrogate the PTv controls on friction due to the fact that a wide range of mechanisms can be easily accessed in the lab at geologically relevant conditions. In addition, carbonate-rich layers make up a significant component of subducting sediments around the world and may impact the frictional behavior of shallow subduction zones. In order to investigate the effect of carbonate subduction and the evolution of friction at subduction zone conditions, we conducted deformation experiments on input sediments for two subduction zones, the Hikurangi trench, New Zealand (ODP Site 1124) and the Peru trench (DSDP Site 321), which have carbonate/clay contents of 40/60 wt% and 80/20 wt%, respectively. Samples were saturated with distilled water mixed with 35g/l sea salt and deformed at room temperature. Experiments were conducted at σeff = 1-100 MPa and T = 20-100 °C with sliding velocities of 1-300 μm/s and hold times of 1-1000 s. We test the changes in velocity dependence and healing over these PT conditions to elucidate the frictional behavior of carbonates in subduction zone settings. The mechanical results are complemented by microstructural analysis. In lower stress experiments, there is no obvious shear localization; however, by 25 MPa, pervasive boundary-parallel shears become dominant, particularly in the Peru samples. Optical observations of these shear zones under cross-polarized light show evidence of plastic deformation (CPO development) while SEM-EDS observations indicate phase segregation in the boundary shears. Degree of microstructural localization appears to correspond with the trends observed in velocity-dependence. Our preliminary results indicate that carbonate/clay compositions could have a significant impact on the frictional behavior of subducting sediments.

RO4929097 and Capecitabine in Treating Patients With Refractory Solid Tumors

ClinicalTrials.gov

2014-11-06

Adult Grade III Lymphomatoid Granulomatosis; Adult Nasal Type Extranodal NK/T-cell Lymphoma; AIDS-related Diffuse Large Cell Lymphoma; AIDS-related Diffuse Mixed Cell Lymphoma; AIDS-related Diffuse Small Cleaved Cell Lymphoma; AIDS-related Immunoblastic Large Cell Lymphoma; AIDS-related Lymphoblastic Lymphoma; AIDS-related Peripheral/Systemic Lymphoma; AIDS-related Primary CNS Lymphoma; AIDS-related Small Noncleaved Cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; HER2-negative Breast Cancer; HIV-associated Hodgkin Lymphoma; Intraocular Lymphoma; Male Breast Cancer; Nodal Marginal Zone B-cell Lymphoma; Post-transplant Lymphoproliferative Disorder; Primary Central Nervous System Hodgkin Lymphoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Breast Cancer; Recurrent Colon Cancer; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Rectal Cancer; Recurrent Small Lymphocytic Lymphoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Hodgkin Lymphoma; Stage III Adult Immunoblastic Large Cell Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Adult T-cell Leukemia/Lymphoma; Stage III Colon Cancer; Stage III Cutaneous T-cell Non-Hodgkin Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Mycosis Fungoides/Sezary Syndrome; Stage III Rectal Cancer; Stage III Small Lymphocytic Lymphoma; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Breast Cancer; Stage IV Colon Cancer; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Rectal Cancer; Stage IV Small Lymphocytic Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

MR thermometry analysis of sonication accuracy and safety margin of volumetric MR imaging-guided high-intensity focused ultrasound ablation of symptomatic uterine fibroids.

PubMed

Kim, Young-sun; Trillaud, Hervé; Rhim, Hyunchul; Lim, Hyo K; Mali, Willem; Voogt, Marianne; Barkhausen, Jörg; Eckey, Thomas; Köhler, Max O; Keserci, Bilgin; Mougenot, Charles; Sokka, Shunmugavelu D; Soini, Jouko; Nieminen, Heikki J

2012-11-01

To evaluate the accuracy of the size and location of the ablation zone produced by volumetric magnetic resonance (MR) imaging-guided high-intensity focused ultrasound ablation of uterine fibroids on the basis of MR thermometric analysis and to assess the effects of a feedback control technique. This prospective study was approved by the institutional review board, and written informed consent was obtained. Thirty-three women with 38 uterine fibroids were treated with an MR imaging-guided high-intensity focused ultrasound system capable of volumetric feedback ablation. Size (diameter times length) and location (three-dimensional displacements) of each ablation zone induced by 527 sonications (with [n=471] and without [n=56] feedback) were analyzed according to the thermal dose obtained with MR thermometry. Prospectively defined acceptance ranges of targeting accuracy were ±5 mm in left-right (LR) and craniocaudal (CC) directions and ±12 mm in anteroposterior (AP) direction. Effects of feedback control in 8- and 12-mm treatment cells were evaluated by using a mixed model with repeated observations within patients. Overall mean sizes of ablation zones produced by 4-, 8-, 12-, and 16-mm treatment cells (with and without feedback) were 4.6 mm±1.4 (standard deviation)×4.4 mm±4.8 (n=13), 8.9 mm±1.9×20.2 mm±6.5 (n=248), 13.0 mm±1.2×29.1 mm±5.6 (n=234), and 18.1 mm±1.4×38.2 mm±7.6 (n=32), respectively. Targeting accuracy values (displacements in absolute values) were 0.9 mm±0.7, 1.2 mm±0.9, and 2.8 mm±2.2 in LR, CC, and AP directions, respectively. Of 527 sonications, 99.8% (526 of 527) were within acceptance ranges. Feedback control had no statistically significant effect on targeting accuracy or ablation zone size. However, variations in ablation zone size were smaller in the feedback control group. Sonication accuracy of volumetric MR imaging-guided high-intensity focused ultrasound ablation of uterine fibroids appears clinically acceptable and may be further improved by feedback control to produce more consistent ablation zones. © RSNA, 2012

Enrichment of rare earth elements as environmental tracers of contamination by acid mine drainage in salt marshes: a new perspective.

PubMed

Delgado, Joaquín; Pérez-López, Rafael; Galván, Laura; Nieto, José Miguel; Boski, Tomasz

2012-09-01

Rare earth elements (REE) were analyzed in surface sediments from the Guadiana Estuary (SW Iberian Pyrite Belt). NASC (North American Shale Composite) normalized REE patterns show clearly convex curvatures in middle-REE (MREE) with respect to light- and heavy-REE, indicating acid-mixing processes between fluvial waters affected by acid mine drainage (AMD) and seawater. However, REE distributions in the mouth (closer to the coastal area) show slightly LREE-enriched and flat patterns, indicating saline-mixing processes typical of the coastal zone. NASC-normalized ratios (La/Gd and La/Yb) do not discriminate between both mixing processes in the estuary. Instead, a new parameter (E(MREE)) has been applied to measure the curvature in the MREE segment. The values of E(MREE)>0 are indicative of acid signatures and their spatial distribution reveal the existence of two decantation zones from flocculation processes related to drought periods and flood events. Studying REE fractionation through the E(MREE) may serve as a good proxy for AMD-pollution in estuarine environments in relation to the traditional methods. Copyright © 2012 Elsevier Ltd. All rights reserved.

Protected areas and agricultural expansion: Biodiversity conservation versus economic growth in the Southeast of Brazil.

PubMed

Moraes, Mayra Cristina Prado de; Mello, Kaline de; Toppa, Rogério Hartung

2017-03-01

The conversion of natural ecosystems to agricultural land and urban areas plays a threat to the protected areas and the natural ecosystems conservation. The aim of this paper is to provide an analysis of the agricultural expansion and its impact on the landscape spatial and temporal patterns in a buffer zone of a protected area located in the transition zone between the Atlantic Forest and Cerrado, in the State of São Paulo, Brazil. The land use and land cover were mapped between 1971 and 2008 and landscape metrics were calculated to provide a spatiotemporal analysis of the forest structure and the expansion of the croplands. The results showed that the landscape patterns were affected by the economic cycles. The predominant crop surrounding the protected area is sugar cane, which increased by 39% during this period, followed by citrus. This landscape change is connected to the Brazilian oil crisis in 1973. The rapid expansion of sugar cane was largely driven by Brazil's biofuel program, the "Proálcool" (pro-alcohol), a project in 1975 that mixed ethanol with gas for automotive fuel. The forest loss occurred mainly between 1971 and 1988, decreasing the forest cover from 17% in 1971 to 12.7% in 2008. Most of the forest patches are smaller than 50 ha and has low connectivity. Throughout the years, the fragments in the buffer zone have become smaller and with an elongated shape, and the park has become isolated. This forest fragmentation process and the predominance of monoculture lands in the buffer zone threaten the protected areas, and can represent a barrier for these areas to provide the effective biodiversity conservation. The measures proposed are necessary to ensure the capability of this ecosystem to sustain its original biodiversity. Copyright © 2016 Elsevier Ltd. All rights reserved.

On the origin of period changes in RR Lyrae stars

NASA Technical Reports Server (NTRS)

Renzini, A.; Sweigart, A. V.

1980-01-01

The observed period changes are explained with respect to the behavior of the semiconductive zone (SCZ) within the core of an RR Lyrae star. General consideration are given which suggest that the composition changes occuring within the SCZ during the horizontal-branch evolution result from many small mixing events, each of which slightly perturbs the pulsation period. Results indicate that small mixing events within the core of an RR Lyrae star can produce changes in the pulsation period comparable with those typically observed. It is further indicated that these mixing events together with the nuclear burning between them can produce period changes of both signs.

The mixing of particle clouds plunging into water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Angelini, S.; Theofanous, T.G.; Yuen, W.W.

This work addresses certain fundamental aspects of the premixing phase of steam explosions, At issue are the multifield interaction aspects under highly transient, multidimensional conditions, and in presence of strong phase changes. They are addressed in an experiment (the MAGICO-2000) involving well-characterized particle clouds mixing with water, and detailed measurements on both external and internal characteristics of the mixing zone. Both cold and hot (up to 1500{degrees}C) particle clouds are considered in conjunction with saturated and subcooled water pools. The PMALPHA code is used as an aid in interpreting the experimental results, and the exercise reveals good predictive capabilities formore » it.« less

Swirl effect on flow structure and mixing in a turbulent jet

NASA Astrophysics Data System (ADS)

Kravtsov, Z. D.; Sharaborin, D. K.; Dulin, V. M.

2018-03-01

The paper reports on experimental study of turbulent transport in the initial region of swirling turbulent jets. The particle image velocimetry and planar laser-induced fluorescence techniques are used to investigate the flow structure and passive scalar concentration, respectively, in free air jet with acetone vapor. Three flow cases are considered, viz., non-swirling jets and swirling jets with and without vortex breakdown and central recirculation zone. Without vortex breakdown, the swirl is shown to promote jet mixing with surrounding air and to decrease the jet core length. The vortex core breakdown further enhances mixing as the jet core disintegrates at the nozzle exit.

Implications of soil mixing for NAPL source zone remediation: Column studies and modeling of field-scale systems

NASA Astrophysics Data System (ADS)

Olson, Mitchell R.; Sale, Tom C.

2015-06-01

Soil remediation is often inhibited by subsurface heterogeneity, which constrains contaminant/reagent contact. Use of soil mixing techniques for reagent delivery provides a means to overcome contaminant/reagent contact limitations. Furthermore, soil mixing reduces the permeability of treated soils, thus extending the time for reactions to proceed. This paper describes research conducted to evaluate implications of soil mixing on remediation of non-aqueous phase liquid (NAPL) source zones. The research consisted of column studies and subsequent modeling of field-scale systems. For column studies, clean influent water was flushed through columns containing homogenized soils, granular zero valent iron (ZVI), and trichloroethene (TCE) NAPL. Within the columns, NAPL depletion occurred due to dissolution, followed by either column-effluent discharge or ZVI-mediated degradation. Complete removal of TCE NAPL from the columns occurred in 6-8 pore volumes of flow. However, most of the TCE (> 96%) was discharged in the column effluent; less than 4% of TCE was degraded. The low fraction of TCE degraded is attributed to the short hydraulic residence time (< 4 days) in the columns. Subsequently, modeling was conducted to scale up column results. By scaling up to field-relevant system sizes (> 10 m) and reducing permeability by one-or-more orders of magnitude, the residence time could be greatly extended, potentially for periods of years to decades. Model output indicates that the fraction of TCE degraded can be increased to > 99.9%, given typical post-mixing soil permeability values. These results suggest that remediation performance can be greatly enhanced by combining contaminant degradation with an extended residence time.

Seasonal changes in the chemistry and biology of a meromictic lake (Big Soda Lake, Nevada, U.S.A.)

USGS Publications Warehouse

Cloern, J.E.; Cole, B.E.; Oremland, R.S.

1983-01-01

Big Soda Lake is an alkaline, saline lake with a permanent chemocline at 34.5 m and a mixolimnion that undergoes seasonal changes in temperature structure. During the period of thermal stratification, from summer through fall, the epilimnion has low concentrations of dissolved inorganic nutrients (N, Si) and CH4, and low biomass of phytoplankton (chlorophyll a ca. 1 mgm -3). Dissolved oxygen disappears near the compensation depth for algal photosynthesis (ca. 20 m). Surface water is transparent so that light is present in the anoxic hypolimnion, and a dense plate of purple sulfur photosynthetic bacteria (Ectothiorhodospira vacuolata) is present just below 20 m (Bchl a ca. 200 mgm-3). Concentrations of N H4+, Si, and CH4 are higher in the hypolimnion than in the epilimnion. As the mixolimnion becomes isothermal in winter, oxygen is mixed down to 28 m. Nutrients (NH4+, Si) and CH4 are released from the hypolimnion and mix to the surface, and a diatom bloom develops in the upper 20 m (chlorophyll a > 40 mgm-3). The deeper mixing of oxygen and enhanced light attenuation by phytoplankton uncouple the anoxic zone and photic zone, and the plate of photosynthetic bacteria disappears (Bchl a ca.10mgm-3). Hence, seasonal changes in temperature distribution and mixing create conditions such that the primary producer community is alternately dominated by phytoplankton and photosynthetic bacteria: the phytoplankton may be nutrient-limited during periods of stratification and the photosynthetic bacteria are light-limited during periods of mixing. ?? 1983 Dr W. Junk Publishers.

Decadal change of the south Atlantic ocean Angola-Benguela frontal zone since 1980

NASA Astrophysics Data System (ADS)

Vizy, Edward K.; Cook, Kerry H.; Sun, Xiaoming

2018-01-01

High-resolution simulations with a regional atmospheric model coupled to an intermediate-level mixed layer ocean model along with multiple atmospheric and oceanic reanalyses are analyzed to understand how and why the Angola-Benguela frontal Zone (ABFZ) has changed since 1980. A southward shift of 0.05°-0.55° latitude decade-1 in the annual mean ABFZ position accompanied by an intensification of + 0.05 to + 0.13 K/100-km decade-1 has occurred as ocean mixed layer temperatures have warmed (cooled) equatorward (poleward) of the front over the 1980-2014 period. These changes are captured in a 35-year model integration. The oceanic warming north of the ABFZ is associated with a weakening of vertical entrainment, reduced cooling associated with vertical diffusion, and a deepening of the mixed layer along the Angola coast. These changes coincide with a steady weakening of the onshore atmospheric flow as the zonal pressure gradient between the eastern equatorial Atlantic and the Congo Basin weakens. Oceanic cooling poleward of the ABFZ is primarily due to enhanced advection of cooler water from the south and east, increased cooling by vertical diffusion, and shoaling of the mixed layer depth. In the atmosphere, these changes are related to an intensification and poleward shift of the South Atlantic sub-tropical anticyclone as surface winds, hence the westward mixed layer ocean currents, intensify in the Benguela upwelling region along the Namibian coast. With a few caveats, these findings demonstrate that air/sea interactions play a prominent role in influencing the observed decadal variability of the ABFZ over the southeastern Atlantic since 1980.

Characterizing shallow secondary clarifier performance where conventional flux theory over-estimates allowable solids loading rate.

PubMed

Daigger, Glen T; Siczka, John S; Smith, Thomas F; Frank, David A; McCorquodale, J A

The performance characteristics of relatively shallow (3.3 and 3.7 m sidewater depth in 30.5 m diameter) activated sludge secondary clarifiers were extensively evaluated during a 2-year testing program at the City of Akron Water Reclamation Facility (WRF), Ohio, USA. Testing included hydraulic and solids loading stress tests, and measurement of sludge characteristics (zone settling velocity (ZSV), dispersed and flocculated total suspended solids), and the results were used to calibrate computational fluid dynamic (CFD) models of the various clarifiers tested. The results demonstrated that good performance could be sustained at surface overflow rates in excess of 3 m/h, as long as the clarifier influent mixed liquor suspended solids (MLSS) concentration was controlled to below critical values. The limiting solids loading rate (SLR) was significantly lower than the value predicted by conventional solids flux analysis based on the measured ZSV/MLSS relationship. CFD analysis suggested that this resulted because mixed liquor entering the clarifier was being directed into the settled sludge blanket, diluting it and also creating a 'thin' concentration sludge blanket that overlays the thicker concentration sludge blanket typically expected. These results indicate the need to determine the allowable SLR for shallow clarifiers using approaches other than traditional solids flux analysis. A combination of actual testing and CFD analyses are demonstrated here to be effective in doing so.

Single-cell computational analysis of light harvesting in a flat-panel photo-bioreactor.

PubMed

Loomba, Varun; Huber, Gregor; von Lieres, Eric

2018-01-01

Flat-panel photo-bioreactors (PBRs) are customarily applied for investigating growth of microalgae. Optimal design and operation of such reactors is still a challenge due to complex non-linear combinations of various impact factors, particularly hydrodynamics, light irradiation, and cell metabolism. A detailed analysis of single-cell light reception can lead to novel insights into the complex interactions of light exposure and algae movement in the reactor. The combined impacts of hydrodynamics and light irradiation on algae cultivation in a flat-panel PBR were studied by tracing the light exposure of individual cells over time. Hydrodynamics and turbulent mixing in this air-sparged bioreactor were simulated using the Eulerian approach for the liquid phase and a slip model for the gas phase velocity profiles. The liquid velocity was then used for tracing single cells and their light exposure, using light intensity profiles obtained from solving the radiative transfer equation at different wavelengths. The residence times of algae cells in defined dark and light zones of the PBR were statistically analyzed for different algal concentrations and sparging rates. The results indicate poor mixing caused by the reactor design which can be only partially improved by increased sparging rates. The results provide important information for optimizing algal biomass productivity by improving bioreactor design and operation and can further be utilized for an in-depth analysis of algal growth by using advanced models of cell metabolism.

Inhalation exposure to cleaning products: application of a two-zone model.

PubMed

Earnest, C Matt; Corsi, Richard L

2013-01-01

In this study, modifications were made to previously applied two-zone models to address important factors that can affect exposures during cleaning tasks. Specifically, we expand on previous applications of the two-zone model by (1) introducing the source in discrete elements (source-cells) as opposed to a complete instantaneous release, (2) placing source cells in both the inner (near person) and outer zones concurrently, (3) treating each source cell as an independent mixture of multiple constituents, and (4) tracking the time-varying liquid concentration and emission rate of each constituent in each source cell. Three experiments were performed in an environmentally controlled chamber with a thermal mannequin and a simplified pure chemical source to simulate emissions from a cleaning product. Gas phase concentration measurements were taken in the bulk air and in the breathing zone of the mannequin to evaluate the model. The mean ratio of the integrated concentration in the mannequin's breathing zone to the concentration in the outer zone was 4.3 (standard deviation, σ = 1.6). The mean ratio of measured concentration in the breathing zone to predicted concentrations in the inner zone was 0.81 (σ = 0.16). Intake fractions ranged from 1.9 × 10(-3) to 2.7 × 10(-3). Model results reasonably predict those of previous exposure monitoring studies and indicate the inadequacy of well-mixed single-zone model applications for some but not all cleaning events.

Effect of different filler wires on weld formation for fiber laser welding 6A02 Aluminum alloy

NASA Astrophysics Data System (ADS)

Xu, F.; Chen, L.; Lu, W.; He, E. G.

2017-12-01

6A02 aluminum alloy was welded by fibre laser welding with two different filler wires (ER4043 and ER5356). The weld apperance, microstructure and mechanical properties were analysed. The results show the welding course with ER4043 is more stable than that with ER5356, and the welding spatters of the former are smaller than that of the latter. The microsturtrue of the weld zone, including columnar-grains near the fusion zone and mixed microstructures (columnar grains and equiaxed grains) in the weld center zone, is finer with ER5356 than that with ER4043. So the average microhardness value of the former is higher than the latter. A great number of low melting point eutectic phases disperse in grains boundary. Due to the eutectic phases distributing more in two zones (overheat zone near the fusion zone and the weld center zone) than other zones, the welded joints have these two low hardness and weak strength zones. The ultimate strength and the elongations after fracture of the welded joints with ER4043 are lower than that with ER5356 slihgtly. However, the former are improved obviously and higher than the latter after heat treatment. The tensile properties of all joints can reach to the base material level. And the tensile fractures always occur near the fusion zone.

Summer Stratification and Fall Overturn--In a Jar.

ERIC Educational Resources Information Center

Foley, Arlene F.

1984-01-01

Provided are procedures for a demonstration which illustrates the concept of summer stratification of lakes in the temperate zone as maintained by thermal resistance to mixing. The demonstration requires only food coloring, water, and common laboratory equipment. (JN)

Enhanced air/fuel mixing for automotive stirling engine turbulator-type combustors

DOEpatents

Riecke, George T.; Stotts, Robert E.

1992-01-01

The invention relates to the improved combustion of fuel in a combustion chamber of a stirling engine and the like by dividing combustion into primary and secondary combustion zones through the use of a diverter plate.

Seasonal changes in the spatial distribution of phytoplankton in small, temperate-zone lakes

USGS Publications Warehouse

Cloern, J.E.; Alpine, A.E.; Cole, B.E.; Heller, T.

1992-01-01

Sampling across two N Minnesota small lakes shows that phytoplankton patchiness is greatly enhanced during winter ice-cover relative to the open-water seasons of exposure to wind stress and rapid turbulent mixing. -Authors

Closing the Loop on Space Waste

NASA Astrophysics Data System (ADS)

Meier, A. J.; Hintze, P. E.

2018-02-01

A heat transfer study of mission mixed waste streams in a reactor hot zone, along with solid, tar, and water recovery. This research enables reliability and benefit on waste conversion systems to manage our environmental impact, on- and off-Earth.

17-N-Allylamino-17-Demethoxygeldanamycin in Treating Patients With Advanced Epithelial Cancer, Malignant Lymphoma, or Sarcoma

ClinicalTrials.gov

2013-02-06

AIDS-related Peripheral/Systemic Lymphoma; AIDS-related Primary CNS Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Chondrosarcoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Osteosarcoma; Nodal Marginal Zone B-cell Lymphoma; Ovarian Sarcoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Osteosarcoma; Recurrent Small Lymphocytic Lymphoma; Recurrent Uterine Sarcoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult Soft Tissue Sarcoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Stage IV Uterine Sarcoma; Unspecified Adult Solid Tumor, Protocol Specific

Hydrothermal alteration in oceanic ridge volcanics: A detailed study at the Galapagos Fossil Hydrothermal Field

USGS Publications Warehouse

Ridley, W.I.; Perfit, M.R.; Josnasson, I.R.; Smith, M.F.

1994-01-01

The Galapagos Fossil Hydrothermal Field is composed of altered oceanic crust and extinct hydrothermal vents within the eastern Galapagos Rift between 85??49???W and 85??55???W. The discharge zone of the hydrothermal system is revealed along scarps, thus providing an opportunity to examine the uppermost mineralized, and highly altered interior parts of the crust. Altered rocks collected in situ by the submersible ALVIN show complex concentric alteration zones. Microsamples of individual zones have been analysed for major/minor, trace elements, and strontium isotopes in order to describe the complex compositional details of the hydrothermal alteration. Interlayered chlorite-smectite and chlorite with disequilibrium compositions dominate the secondary mineralogy as replacement phases of primary glass and acicular pyroxene. Phenocrysts and matrix grains of plagioclase are unaffected during alteration. Using a modification of the Gresens' equation we demonstrate that the trivalent rare earth elements (REEs) are relatively immobile, and calculate degrees of enrichment and depletion in other elements. Strontium isotopic ratios increase as Sr concentrations decrease from least-altered cores to most-altered rims and cross-cutting veins in individual samples, and can be modeled by open system behaviour under low fluid-rock ratio (< 10) conditions following a period of lower-temperature weathering of volcanics within the rift zone. The complex patterns of element enrichment and depletion and strontium isotope variations indicate mixing between pristine seawater and ascending hot fluids to produce a compositional spectrum of fluids. The precipitation of base-metal sulfides beneath the seafloor is probably a result of fluid mixing and cooling. If, as suggested here, the discharge zone alteration occurred under relatively low fluid-rock ratios, then this shallow region must play an important role in determining the exit composition of vent fluids in marine hydrothermal systems. ?? 1994.

Mixing zone hydrodynamics in a large confluence: a case study of the Snake and Clearwater Rivers confluence

NASA Astrophysics Data System (ADS)

Shehata, M. M.; Petrie, J.

2015-12-01

Confluences are a basic component in all fluvial systems, which are often characterized by complex flow and sediment transport patterns. Addressing confluences, however, started only recently in parallel with new advances of flow measurement tools and computational techniques. A limited number of field studies exist investigating flow hydrodynamics through confluences, particularly for large confluences with central zone widths of 100 m or greater. Previous studies have indicated that the size of the confluent rivers and the post-confluence zone may impact flow and sediment transport processes in the confluence zone, which consequently could impact the biodiversity within the river network. This study presents the results of a field study conducted at the confluence of the Snake and the Clearwater rivers near the towns of Clarkston, WA and Lewiston, ID (average width of 700 m at the confluence center). This confluence supports many different and, sometimes, conflicting purposes including commercial navigation, recreation, and fish and wildlife conservation. The confluence properties are affected by dredging operations carried out periodically to maintain the minimum water depth required for safe flow conveyance and navigation purposes. Also, a levee system was constructed on the confluence banks as an extra flood control measure. In the recent field work, an Acoustic Doppler Current Profiler was used to measure water velocity profiles at cross sections in the confluence region. Fixed and moving vessel measurements were taken at selected locations to evaluate both the spatial and temporal variation in velocity throughout the confluence. The confluence bathymetry was surveyed with a multi-beam sonar to investigate existent bed morphological elements. The results identify the velocity pattern in the mixing zone between the two rivers. The present findings are compared to previous studies on small confluences to demonstrate the influence of scale on flow processes.

PMP Estimations at Sparsely Controlled Andinian Basins and Climate Change Projections

NASA Astrophysics Data System (ADS)

Lagos Zúñiga, M. A.; Vargas, X.

2012-12-01

Probable Maximum Precipitation (PMP) estimation implies an extensive review of hydrometeorological data and understandig of precipitation formation processes. There exists different methodology processes that apply for their estimations and all of them require a good spatial and temporal representation of storms. The estimation of hydrometeorological PMP on sparsely controlled basins is a difficult task, specially if the studied area has an important orographic effect due to mountains and the mixed precipitation occurrence in the most several storms time period, the main task of this study is to propose and estimate PMP in a sparsely controlled basin, affected by abrupt topography and mixed hidrology basin; also analyzing statystic uncertainties estimations and possible climate changes effects in its estimation. In this study the PMP estimation under statistical and hydrometeorological aproaches (watershed-based and traditional depth area duration analysis) was done in a semi arid zone at Puclaro dam in north Chile. Due to the lack of good spatial meteorological representation at the study zone, we propose a methodology to consider the orographic effects of Los Andes due to orographic effects patterns based in a RCM PRECIS-DGF and annual isoyetal maps. Estimations were validated with precipitation patterns for given winters, considering snow route and rainfall gauges at the preferencial wind direction, finding good results. The estimations are also compared with the highest areal storms in USA, Australia, India and China and with frequency analysis in local rain gauge stations in order to decide about the most adequate approach for the study zone. Climate change projections were evaluated with ECHAM5 GCM model, due to its good quality representation in the seasonality and the magnitude of meteorological variables. Temperature projections, for 2040-2065 period, show that there would be a rise in the catchment contributing area that would lead to an increase of the average liquid precipitation over the basin. Temperature projections would also affect the maximization factors in the calculation of the PMP, increasing it up to 126.6% and 62.5% in scenarios A2 and B1, respectively. These projections are important to be studied due to the implications of PMP in hydrologic design of great hydraulic works as Probable Maximum Flood (PMF). We propose that the methodology presented in this study could be also used in other basins of similar characteristics.

Marginal Ice Zone Processes Observed from Unmanned Aerial Systems

NASA Astrophysics Data System (ADS)

Zappa, C. J.

2015-12-01

Recent years have seen extreme changes in the Arctic. Marginal ice zones (MIZ), or areas where the "ice-albedo feedback" driven by solar warming is highest and ice melt is extensive, may provide insights into the extent of these changes. Furthermore, MIZ play a central role in setting the air-sea CO2 balance making them a critical component of the global carbon cycle. Incomplete understanding of how the sea-ice modulates gas fluxes renders it difficult to estimate the carbon budget in MIZ. Here, we investigate the turbulent mechanisms driving mixing and gas exchange in leads, polynyas and in the presence of ice floes using both field and laboratory measurements. Measurements from unmanned aerial systems (UAS) in the marginal ice zone were made during 2 experiments: 1) North of Oliktok Point AK in the Beaufort Sea were made during the Marginal Ice Zone Ocean and Ice Observations and Processes EXperiment (MIZOPEX) in July-August 2013 and 2) Fram Strait and Greenland Sea northwest of Ny-Ålesund, Svalbard, Norway during the Air-Sea-Ice Physics and Biogeochemistry Experiment (ASIPBEX) April - May 2015. We developed a number of new payloads that include: i) hyperspectral imaging spectrometers to measure VNIR (400-1000 nm) and NIR (900-1700 nm) spectral radiance; ii) net longwave and net shortwave radiation for ice-ocean albedo studies; iii) air-sea-ice turbulent fluxes as well as wave height, ice freeboard, and surface roughness with a LIDAR; and iv) drone-deployed micro-drifters (DDµD) deployed from the UAS that telemeter temperature, pressure, and RH as it descends through the atmosphere and temperature and salinity of the upper meter of the ocean once it lands on the ocean's surface. Visible and IR imagery of melting ice floes clearly defines the scale of the ice floes. The IR imagery show distinct cooling of the skin sea surface temperature (SST) as well as an intricate circulation and mixing pattern that depends on the surface current, wind speed, and near-surface vertical temperature/salinity structure. Individual ice floes develop turbulent wakes as they drift and cause transient mixing of an influx of colder surface (fresh) melt water. We capture a melting and mixing event that explains the changing pattern observed in skin SST and is substantiated using laboratory experiments.

Gas sampling method for determining pollutant concentrations in the flame zone of two swirl-can combustor modules

NASA Technical Reports Server (NTRS)

Duerr, R. A.

1975-01-01

A gas sampling probe and traversing mechanism were developed to obtain detailed measurements of gaseous pollutant concentrations in the primary and mixing regions of combustors in order to better understand how pollutants are formed. The gas sampling probe was actuated by a three-degree-of-freedom traversing mechanism and the samples obtained were analyzed by an on-line gas analysis system. The pollutants in the flame zone of two different swirl-can combustor modules were measured at an inlet-air temperature of 590 K, pressure of 6 atmospheres, and reference velocities of 23 and 30 meters per second at a fuel-air ratio of 0.02. Typical results show large spatial gradients in the gaseous pollutant concentration close to the swirl-can module. Average concentrations of unburned hydrocarbons and carbon monoxide decrease rapidly in the downstream wake regions of each module. By careful and detailed probing, the effect of various module design features on pollutant formation can be assessed. The techniques presently developed seem adequate to obtain the desired information.

Assessment of land influence on a high-latitude marine coastal system: Tierra del Fuego, southernmost Argentina.

PubMed

Amin, Oscar; Comoglio, Laura; Spetter, Carla; Duarte, Claudia; Asteasuain, Raúl; Freije, Rubén Hugo; Marcovecchio, Jorge

2011-04-01

The study deals with the determination of physico-chemical parameters, inorganic nutrients, particulate organic matter, and photosynthetic pigments on a monthly basis during an annual cycle from nine sampling sites of the coastal zone of a high-latitude ecosystem (Tierra del Fuego, Argentina). Nitrites and phosphates concentrations were similar to other systems of the south Atlantic coast (median, 0.30 and 1.02 μM, respectively), while nitrates were higher in all sampling periods (median, 45.37 μM), and silicates were significantly smaller (median, 7.76 μM). Chlorophyll a and phaeopigments have shown median values of 0.38 and 0.85 mg m(-3), respectively, while saturated values of dissolved oxygen were recorded throughout the study. The analysis reflected that nutrient enrichment seems to be linked to an anthropogenic source, the presence of peatlands areas, and a sink of Nothofagus pumilio woods. The area could be characterized in three zones related to (1) high urban influence, (2) natural inputs of freshwater, and (3) mixed inputs coming from moderate urban impacts.

Example study for granular bioreactor stratification: Three-dimensional evaluation of a sulfate-reducing granular bioreactor

PubMed Central

Hao, Tian-wei; Luo, Jing-hai; Su, Kui-zu; Wei, Li; Mackey, Hamish R.; Chi, Kun; Chen, Guang-Hao

2016-01-01

Recently, sulfate-reducing granular sludge has been developed for application in sulfate-laden water and wastewater treatment. However, little is known about biomass stratification and its effects on the bioprocesses inside the granular bioreactor. A comprehensive investigation followed by a verification trial was therefore conducted in the present work. The investigation focused on the performance of each sludge layer, the internal hydrodynamics and microbial community structures along the height of the reactor. The reactor substratum (the section below baffle 1) was identified as the main acidification zone based on microbial analysis and reactor performance. Two baffle installations increased mixing intensity but at the same time introduced dead zones. Computational fluid dynamics simulation was employed to visualize the internal hydrodynamics. The 16S rRNA gene of the organisms further revealed that more diverse communities of sulfate-reducing bacteria (SRB) and acidogens were detected in the reactor substratum than in the superstratum (the section above baffle 1). The findings of this study shed light on biomass stratification in an SRB granular bioreactor to aid in the design and optimization of such reactors. PMID:27539264

Intra- and inter-group coordination patterns reveal collective behaviors of football players near the scoring zone.

PubMed

Duarte, Ricardo; Araújo, Duarte; Freire, Luís; Folgado, Hugo; Fernandes, Orlando; Davids, Keith

2012-12-01

This study examined emergent coordination processes in collective patterns of behavior in 3 vs 3 sub-phases of the team sport of association football near the scoring zone. We identified coordination tendencies for the centroid (i.e., team center) and surface area (i.e., occupied space) of each sub-group of performers (n=20 plays). We also compared these kinematic variables at three key moments of play using mixed-model ANOVAs. The centroids demonstrated a strong symmetric relation that described the coordinated attacking/defending actions of performers in this sub-phase of play. Conversely, analysis of the surface area of each team did not reveal a clear coordination pattern between sub-groups. But the difference in the occupied area between the attacking and defending sub-groups significantly increased over time. Findings emphasized that major changes in sub-group behaviors occurred just before an assisted pass was made (i.e., leading to a loss of stability in the 3 vs 3 sub-phases). Copyright © 2012 Elsevier B.V. All rights reserved.

Asteroid taxonomy and the distribution of the compositional types

NASA Technical Reports Server (NTRS)

Zellner, B.

1979-01-01

Physical observations of minor planets documented in the TRIAD computer file are used to classify 752 objects into the broad compositional types C, S, M, E, R, and U (unclassifiable) according to the prescriptions adopted by Bowell et al. (1978). Diameters are computed from the photometric magnitude using radiometric and/or polarimetric data where available, or else from albedos characteristic of the indicated type. An analysis of the observational selection effects leads to tabulation of the actual number of asteroids, as a function of type and diameter, in each of 15 orbital element zones. For the whole main belt the population is 75% of type C, 15% of type S, and 10% of other types, with no belt-wide dependence of the mixing ratios on diameter. In some zones the logarithmic diameter-frequency relations are decidedly nonlinear. The relative frequency of S-type objects decreases smoothly outward through the main belt, with exponential scale length 0.5 AU. The rarer types show a more chaotic, but generally flatter, distribution over distance. Characteristic type distributions, contrasting with the background population, are found for the Eos, Koronis, Nysa and Themis families.

Direct numerical simulations of flow-chemistry interactions in statistically turbulent premixed flames

NASA Astrophysics Data System (ADS)

Arias, Paul; Uranakar, Harshavardhana; Chaudhuri, Swetaprovo; Im, Hong

2015-11-01

The effects of Damköhler number and Karlovitz number on the flame dynamics of three-dimensional statistically planar turbulent premixed flames are investigated by direct numerical simulation incorporating detailed chemistry and transport for a hydrogen-air mixture. The mean inlet velocity was dynamically adjusted to ensure a stable flame within the computational domain, allowing the investigation of time-averaged quantities of interest. A particular interest was on understanding the effects of turbulence on the displacement speed of the flame relative to the local fluid flow. Results show a linear dependence on the displacement speed as a function of total strain, consistent with earlier work on premixed-laminar flames. Additional analysis on the local flame thickness reveals that the effect of turbulence is twofold: (1) the increase in mixing results in flame thinning due to the enhancement of combustion at early onset of the flame, and (2) for large Reynolds number flows, the penetration of the turbulence far into the preheat zone and into the reaction zone results in localized flame broadening.

The Effects of Borides on the Mechanical Properties of TLPB Repaired Inconel 738 Superalloy

NASA Astrophysics Data System (ADS)

Wei, J.; Ye, Y.; Sun, Z.; Zou, G.; Bai, H.; Wu, A.; Liu, L.

2017-10-01

The transient liquid phase diffusion bonding (TLPB) method was used to repair an artificial crack in Inconel 738, which was notched by a femtosecond laser. Mixed ratios of BNi-1a:DF-4B were investigated at the bonding temperature of 1373 K (1100 °C) for 2 to 36 hours. The effect of borides on the mechanical properties of TLPB repaired joints was studied through analysis of the microstructure, fracture path, and morphology observations. The borides formation, morphology, distribution, and joints strength were studied in detail. The results showed that the diffusion of B can either increase or decrease the joint strength, depending on its distribution and morphology. The amount of large blocky Ni-B compounds in the precipitate zone were reduced with increasing holding time, which resulted in an increase in joint strength. Nevertheless, further increasing the holding time led to a decrease in joint strength because of the formation of continuous acicular borides in the diffusion-affected zone. The fracture modes of TLPB joints were also discussed on the basis of the microstructure and fractography.

On sound generation by turbulent convection: A new look at old results

NASA Technical Reports Server (NTRS)

Musielak, Z. E.; Rosner, R.; Stein, R. F.; Ulmschneider, P.

1994-01-01

We have revisited the problem of acoustic wave generation by turbulent convection in stellar atmospheres. The theory of aerodynamically generated sound, originally developed by Lighthill and later modified by Stein to include the effects of stratification, has been used to estimate the acoustic wave energy flux generated in solar and stellar convection zones. We correct the earlier computations by incorporating an improved description of the spatial and temporal spectrum of the turbulent convection. We show the dependence of the resulting wave fluxes on the nature of the turbulence, and compute the wave energy spectra and wave energy fluxes generated in the Sun on the basis of a mixing-length model of the solar convection zone. In contrast to the previous results, we show that the acoustic energy generation does not depend very sensitively on the turbulent energy spectrum. However, typical total acoustic fluxes of order F(sub A) = 5 x 10(exp 7) ergs/sq cm/s with a peak of the acoustic frequency spectrum near omega = 100 mHz are found to be comparable to those previously calculated. The acoustic flux turns out to be strongly dependent on the solar model, scaling with the mixing-length parameter alpha as alpha(exp 3.8). The computed fluxes most likely constitute a lower limit on the acoustic energy produced in the solar convection zone if recent convection simulations suggesting the presence of shocks near the upper layers of the convection zone apply to the Sun.

LED-driven backlights for automotive displays

NASA Astrophysics Data System (ADS)

Strauch, Frank

2007-09-01

As a light source the LED has some advantage over the traditionally used fluorescence tube such as longer life or lower space consumption. Consequently customers are asking for the LED lighting design in their products. We introduced in a company owned backlight the white LED technology. This step opens the possibility to have access to the components in the display market. Instead of having a finalized display product which needs to be integrated in the head unit of a car we assemble the backlight, the glass, own electronics and the housing. A major advantage of this concept is the better control of the heat flow generated by the LEDs to the outer side because only a common housing is used for all the components. Also the requirement for slim products can be fulfilled. As always a new technology doesn't come with advantages only. An LED represents a point source compared to the well-known tube thus requiring a mixing zone for the multiple point sources when they enter a light guide. This zone can't be used in displays because of the lack of homogeneity. It's a design goal to minimize this zone which can be helped by the right choice of the LED in terms of slimness. A step ahead is the implementation of RGB LEDs because of their higher color rendering abilities. This allows for the control of the chromaticity point under temperature change but as a drawback needs a larger mixing zone.

Microstructure and Hardness Profiles of Bifocal Laser-Welded DP-HSLA Steel Overlap Joints

NASA Astrophysics Data System (ADS)

Grajcar, A.; Matter, P.; Stano, S.; Wilk, Z.; Różański, M.

2017-04-01

The article presents results related to the bifocal laser welding of overlap joints made of HSLA and DP high-strength steels. The joints were made using a disk laser and a head enabling the 50-50% distribution of laser power. The effects of the laser welding rates and the distance between laser spots on morphological features and hardness profiles were analyzed. It was established that the positioning of beams at angles of 0° or 90° determined the hardness of the individual zones of the joints, without causing significant differences in microstructures of the steels. Microstructural features were inspected using scanning electron microscopy. Both steels revealed primarily martensitic-bainitic microstructures in the fusion zone and in the heat-affected zone. Mixed multiphase microstructures were revealed in the inter-critical heat-affected zone of the joint. The research involved the determination of parameters making it possible to reduce the hardness of joints and prevent the formation of the soft zone in the dual-phase steel.

Method for converting hydrocarbon fuel into hydrogen gas and carbon dioxide

DOEpatents

Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.

2000-01-01

A method for converting hydrocarbon fuel into hydrogen gas and carbon dioxide within a reformer 10 is disclosed. According to the method, a stream including an oxygen-containing gas is directed adjacent to a first vessel 18 and the oxygen-containing gas is heated. A stream including unburned fuel is introduced into the oxygen-containing gas stream to form a mixture including oxygen-containing gas and fuel. The mixture of oxygen-containing gas and unburned fuel is directed tangentially into a partial oxidation reaction zone 24 within the first vessel 18. The mixture of oxygen-containing gas and fuel is further directed through the partial oxidation reaction zone 24 to produce a heated reformate stream including hydrogen gas and carbon monoxide. Steam may also be mixed with the oxygen-containing gas and fuel, and the reformate stream from the partial oxidation reaction zone 24 directed into a steam reforming zone 26. High- and low-temperature shift reaction zones 64,76 may be employed for further fuel processing.

Effects of Eu3+ concentration on structural, optical and vibrational properties of multifunctional Ce(1-x)Eu(x)O2-delta) nanoparticles synthesized by thermolysis of 2,4-pentanedione complexes.

PubMed

Kremenovic, A; Bozanic, D K; Welsch, A M; Jancar, B; Nikolic, A S; Boskovic, M; Colomban, Ph; Fabian, Martin; Antic, B

2012-12-01

The 5-10 nm Ce(1-x)Eu(x)O(2-delta) (0 < or = x < or = 0.30) nanoparticles with fluorite structure were synthesized by thermal decomposition of Eu- and Ce-2,4-pentanedione complexes mixtures. X-ray line broadening analysis of mixed samples Ce(1-x)Eu(x)O(2-delta) (0.05 < or = x < or = 0.30) showed that the crystallite size was lower and root mean square strain higher than in pure ceria. However, within mixed samples Ce(1-x)Eu(x)O(2-delta) (0.05 < or = x < or = 0.30) crystallite size and root mean square strain were independent of Eu3+ concentration. Raman spectroscopy results indicated that europium ions yield disorder by breaking the phonon propagation and therefore making the non-centre Brillouin zone modes Raman active. The absorption bands in the spectra of mixed oxides were blue-shifted in comparison to pure CeO(2-delta) nanopowder. The samples show red emission typical for Eu ions. The biggest photoluminescent intensity was observed for the highest Eu3+ concentration (x = 0.30) and further enhanced with the increase in crystallinity.

Tunable transport property of oxygen ion in metal oxide thin film: Impact of electrolyte orientation on conductivity.

PubMed

Arunkumar, P; Ramaseshan, R; Dash, S; Babu, K Suresh

2017-06-14

Quest for efficient ion conducting electrolyte thin film operating at intermediate temperature (~600 °C) holds promise for the real-world utilization of solid oxide fuel cells. Here, we report the correlation between mixed as well as preferentially oriented samarium doped cerium oxide electrolyte films fabricated by varying the substrate temperatures (100, 300 and 500 °C) over anode/ quartz by electron beam physical vapor deposition. Pole figure analysis of films deposited at 300 °C demonstrated a preferential (111) orientation in out-off plane direction, while a mixed orientation was observed at 100 and 500 °C. As per extended structural zone model, the growth mechanism of film differs with surface mobility of adatom. Preferential orientation resulted in higher ionic conductivity than the films with mixed orientation, demonstrating the role of growth on electrochemical properties. The superior ionic conductivity upon preferential orientation arises from the effective reduction of anisotropic nature and grain boundary density in highly oriented thin films in out-of-plane direction, which facilitates the hopping of oxygen ion at a lower activation energy. This unique feature of growing an oriented electrolyte over the anode material opens a new approach to solving the grain boundary limitation and makes it as a promising solution for efficient power generation.

Classified and clustered data constellation: An efficient approach of 3D urban data management

NASA Astrophysics Data System (ADS)

Azri, Suhaibah; Ujang, Uznir; Castro, Francesc Antón; Rahman, Alias Abdul; Mioc, Darka

2016-03-01

The growth of urban areas has resulted in massive urban datasets and difficulties handling and managing issues related to urban areas. Huge and massive datasets can degrade data retrieval and information analysis performance. In addition, the urban environment is very difficult to manage because it involves various types of data, such as multiple types of zoning themes in the case of urban mixed-use development. Thus, a special technique for efficient handling and management of urban data is necessary. This paper proposes a structure called Classified and Clustered Data Constellation (CCDC) for urban data management. CCDC operates on the basis of two filters: classification and clustering. To boost up the performance of information retrieval, CCDC offers a minimal percentage of overlap among nodes and coverage area to avoid repetitive data entry and multipath query. The results of tests conducted on several urban mixed-use development datasets using CCDC verify that it efficiently retrieves their semantic and spatial information. Further, comparisons conducted between CCDC and existing clustering and data constellation techniques, from the aspect of preservation of minimal overlap and coverage, confirm that the proposed structure is capable of preserving the minimum overlap and coverage area among nodes. Our overall results indicate that CCDC is efficient in handling and managing urban data, especially urban mixed-use development applications.

[Spatial pattern of forest biomass and its influencing factors in the Great Xing'an Mountains, Heilongjiang Province, China].

PubMed

Wang, Xiao-Li; Chang, Yu; Chen, Hong-Wei; Hu, Yuan-Man; Jiao, Lin-Lin; Feng, Yu-Ting; Wu, Wen; Wu, Hai-Feng

2014-04-01

Based on field inventory data and vegetation index EVI (enhanced vegetation index), the spatial pattern of the forest biomass in the Great Xing'an Mountains, Heilongjiang Province was quantitatively analyzed. Using the spatial analysis and statistics tools in ArcGIS software, the impacts of climatic zone, elevation, slope, aspect and vegetation type on the spatial pattern of forest biomass were explored. The results showed that the forest biomass in the Great Xing'an Mountains was 350 Tg and spatially aggregated with great increasing potentials. Forest biomass density in the cold temperate humid zone (64.02 t x hm(-2)) was higher than that in the temperate humid zone (60.26 t x hm(-2)). The biomass density of each vegetation type was in the order of mixed coniferous forest (65.13 t x hm(-2)) > spruce-fir forest (63.92 t x hm(-2)) > Pinus pumila-Larix gmelinii forest (63.79 t x hm(-2)) > Pinus sylvestris var. mongolica forest (61.97 t x hm(-2)) > Larix gmelinii forest (61.40 t x hm(-2)) > deciduous broadleaf forest (58.96 t x hm(-2)). With the increasing elevation and slope, the forest biomass density first decreased and then increased. The forest biomass density in the shady slopes was greater than that in the sunny slopes. The spatial pattern of forest biomass in the Great Xing' an Mountains exhibited a heterogeneous pattern due to the variation of climatic zone, vegetation type and topographical factor. This spatial heterogeneity needs to be accounted when evaluating forest biomass at regional scales.

In-depth analysis of drivers' merging behavior and rear-end crash risks in work zone merging areas.

PubMed

Weng, Jinxian; Xue, Shan; Yang, Ying; Yan, Xuedong; Qu, Xiaobo

2015-04-01

This study investigates the drivers' merging behavior and the rear-end crash risk in work zone merging areas during the entire merging implementation period from the time of starting a merging maneuver to that of completing the maneuver. With the merging traffic data from a work zone site in Singapore, a mixed probit model is developed to describe the merging behavior, and two surrogate safety measures including the time to collision (TTC) and deceleration rate to avoid the crash (DRAC) are adopted to compute the rear-end crash risk between the merging vehicle and its neighboring vehicles. Results show that the merging vehicle has a bigger probability of completing a merging maneuver quickly under one of the following situations: (i) the merging vehicle moves relatively fast; (ii) the merging lead vehicle is a heavy vehicle; and (iii) there is a sizable gap in the adjacent through lane. Results indicate that the rear-end crash risk does not monotonically increase as the merging vehicle speed increases. The merging vehicle's rear-end crash risk is also affected by the vehicle type. There is a biggest increment of rear-end crash risk if the merging lead vehicle belongs to a heavy vehicle. Although the reduced remaining distance to work zone could urge the merging vehicle to complete a merging maneuver quickly, it might lead to an increased rear-end crash risk. Interestingly, it is found that the rear-end crash risk could be generally increased over the elapsed time after the merging maneuver being triggered. Copyright © 2015 Elsevier Ltd. All rights reserved.

Determination of anisotropic karst features in the Biscayne Aquifer using multi electrical resistivity imaging techniques

NASA Astrophysics Data System (ADS)

Yeboah-Forson, A.; Whitman, D.

2012-12-01

The Biscayne Aquifer of Southeast Florida is characterized by limestone cavities and solution hole features that are often beneath the surface and are difficult to detect and quantify accurately. Electrical resistivity imaging (ERI) is often used to image the subsurface for detection of cavities and other karst features. A recent regional study of electrical anisotropy derived from rotated square array measurements measured coefficients of anisotropy of 1.12 or less. At one particular site however, the coefficient of anisotropy was found to be as high as 1.36 with the average minimum resistivity direction trending 105°. The highest values of anisotropy are found at squares array sizes equivalent to effective depths of 4-9m. The cause of this higher anisotropy and its associated orientation was investigated using a combination of azimuthal 2-D profiles and a 3-D tomography survey using a mixed dipole gradient array. Results indicate a low resistivity zone at a depth of 5-10 m in the saturated zone (10-40Ωm) trending 109° in the 2-D profiles and the presence of low resistivity zone (14-43Ωm) trending 90-105° in the 3-D model. This observed lower resistivity zone is at least 50% lower than the surrounding resistivity. Although further geophysical studies are planned at the site, the primary analysis from these three contrasting ERI techniques indicates that the cause of higher anisotropy might be due to the presence of a solution cavity oriented in the E-SE direction.

Integrated synoptic surveys of the hydrodynamics and water-quality distributions in two Lake Michigan rivermouth mixing zones using an autonomous underwater vehicle and a manned boat

USGS Publications Warehouse

Jackson, P. Ryan; Reneau, Paul C.

2014-01-01

The U.S. Geological Survey (USGS), in cooperation with the National Monitoring Network for U.S. Coastal Waters and Tributaries, launched a pilot project in 2010 to determine the value of integrated synoptic surveys of rivermouths using autonomous underwater vehicle technology in response to a call for rivermouth research, which includes study domains that envelop both the fluvial and lacustrine boundaries of the rivermouth mixing zone. The pilot project was implemented at two Lake Michigan rivermouths with largely different scales, hydrodynamics, and settings, but employing primarily the same survey techniques and methods. The Milwaukee River Estuary Area of Concern (AOC) survey included measurements in the lower 2 to 3 miles of the Milwaukee, Menomonee, and Kinnickinnic Rivers and inner and outer Milwaukee Harbor. This estuary is situated in downtown Milwaukee, Wisconsin, and is the most populated basin that flows directly into Lake Michigan. In contrast, the Manitowoc rivermouth has a relatively small harbor separating the rivermouth from Lake Michigan, and the Manitowoc River Watershed is primarily agricultural. Both the Milwaukee and Manitowoc rivermouths are unregulated and allow free exchange of water with Lake Michigan. This pilot study of the Milwaukee River Estuary and Manitowoc rivermouth using an autonomous underwater vehicle (AUV) paired with a manned survey boat resulted in high spatial and temporal resolution datasets of basic water-quality parameter distributions and hydrodynamics. The AUV performed well in these environments and was found primarily well-suited for harbor and nearshore surveys of three-dimensional water-quality distributions. Both case studies revealed that the use of a manned boat equipped with an acoustic Doppler current profiler (ADCP) and multiparameter sonde (and an optional flow-through water-quality sampling system) was the best option for riverine surveys. To ensure that the most accurate and highest resolution velocity data were collected concurrently with the AUV surveys, the pilot study used a manned boat equipped with an ADCP. Combining the AUV and manned boat datasets resulted in datasets that are essentially continuous from the fluvial through the lacustrine zones of a rivermouth. Whereas the pilot studies were completed during low flows on the tributaries, completion of surveys at higher flows using the same techniques is possible, but the use of the AUV would be limited to areas with relatively low velocities (less than 2 feet per second) such as the harbors and nearshore zones of Lake Michigan. Overall, this pilot study aimed at evaluation of AUV technology for integrated synoptic surveys of rivermouth mixing zones was successful, and the techniques and methods employed in this pilot study should be transferrable to other sites with similar success. The use of the AUV provided significant time savings compared to traditional sampling techniques. For example, the survey of outer Milwaukee Harbor using the AUV required less than 7 hours for approximately 600 profiles compared to the 150 hours it would have taken using traditional methods in a manned boat (a 95 percent reduction in man-hours). The integrated datasets resulting from the AUV and manned survey boat are of high value and present a picture of the mixing and hydrodynamics of these highly dynamic, highly variable rivermouth mixing zones from the relatively well-mixed fluvial environment through the rivermouth to the stratified lacustrine receiving body of Lake Michigan. Such datasets not only allow researchers to understand more about the physical processes occurring in these rivermouths, but they provide high spatial resolution data required for interpretation of relations between disparate point samples and calibration and validation of numerical models.

The Physical, Geochemical and Microbial Conditions and Processes in the Hyporheic Zone of a Large Tidally Influenced River: The Fraser River, British Columbia, Canada

NASA Astrophysics Data System (ADS)

Bianchin, M.; Roschinski, T.; Ross, K.; Leslie, S.; William, M.; Beckie, R.

2006-12-01

The objective of this research is to investigate the physical, chemical and biological conditions and processes that occur in the hyporheic zone of the lower Fraser River, British Columbia. The large flows of between 2000 and 10000 cubic meters per second, the 10 15 m deep, 250 m wide channel, the 1 m tidal fluctuations, the localized scour and redeposition of sediments during freshet and the strong geochemical contrast between groundwater and surface water distinguish this investigation from studies on smaller channels and streams and required the development of novel characterization tools and strategies. The geochemistry of water samples collected with a push-in profiler, bulk electrical conductivity (EC) measurements collected with a push-in tool and hydraulic head measurements indicate that groundwater principally discharges into the river approximately 100 m offshore in a 10 m wide band. River water and groundwater mix to a maximum depth of between 0.75 and 1.5 m. While hydraulic heads show strong tidal reversals, bulk EC profiles show only moderate changes during the tidal cycle. It was hypothesized that high iron (10's mg/L of Fe(II)) in reduced groundwater would precipitate from solution as secondary iron-oxide phases in the zone where groundwater mixes with aerobic river water. Sediments were collected with a freeze-shoe corer and depth profiles through the hyporheic zone and into the underlying aquifer were analyzed by selective extractions. The 15-30 mg/g of total extractable iron in both the aquifer and hyporheic zone is relatively high. The lack of noticeable iron accumulation in the hyporheic zone may indicate that iron precipitates on shallow sediments that are subsequently scoured from the river bed during freshet. Microbial DNA from sediments was analyzed using denaturing gradient gel electrophoresis and showed a relatively diverse community structure but an overall low biomass.

Application of multivariate analysis to investigate the trace element contamination in top soil of coal mining district in Jorong, South Kalimantan, Indonesia

NASA Astrophysics Data System (ADS)

Pujiwati, Arie; Nakamura, K.; Watanabe, N.; Komai, T.

2018-02-01

Multivariate analysis is applied to investigate geochemistry of several trace elements in top soils and their relation with the contamination source as the influence of coal mines in Jorong, South Kalimantan. Total concentration of Cd, V, Co, Ni, Cr, Zn, As, Pb, Sb, Cu and Ba was determined in 20 soil samples by the bulk analysis. Pearson correlation is applied to specify the linear correlation among the elements. Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied to observe the classification of trace elements and contamination sources. The results suggest that contamination loading is contributed by Cr, Cu, Ni, Zn, As, and Pb. The elemental loading mostly affects the non-coal mining area, for instances the area near settlement and agricultural land use. Moreover, the contamination source is classified into the areas that are influenced by the coal mining activity, the agricultural types, and the river mixing zone. Multivariate analysis could elucidate the elemental loading and the contamination sources of trace elements in the vicinity of coal mine area.

Evolution of mixing width induced by general Rayleigh-Taylor instability.

PubMed

Zhang, You-Sheng; He, Zhi-Wei; Gao, Fu-Jie; Li, Xin-Liang; Tian, Bao-Lin

2016-06-01

Turbulent mixing induced by Rayleigh-Taylor (RT) instability occurs ubiquitously in many natural phenomena and engineering applications. As the simplest and primary descriptor of the mixing process, the evolution of mixing width of the mixing zone plays a notable role in the flows. The flows generally involve complex varying acceleration histories and widely varying density ratios, two dominant factors affecting the evolution of mixing width. However, no satisfactory theory for predicting the evolution has yet been established. Here a theory determining the evolution of mixing width in general RT flows is established to reproduce, first, all of the documented experiments conducted for diverse (i.e., constant, impulsive, oscillating, decreasing, increasing, and complex) acceleration histories and all density ratios. The theory is established in terms of the conservation principle, with special consideration given to the asymmetry of the volume-averaged density fields occurring in actual flows. The results reveal the sensitivity or insensitivity of the evolution of a mixing front of a neighboring light or heavy fluid to the degree of asymmetry and thus explain the distinct evolutions in two experiments with the same configurations.

Organic contaminant transport and fate in the subsurface: Evolution of knowledge and understanding

NASA Astrophysics Data System (ADS)

Essaid, Hedeff I.; Bekins, Barbara A.; Cozzarelli, Isabelle M.

2015-07-01

Toxic organic contaminants may enter the subsurface as slightly soluble and volatile nonaqueous phase liquids (NAPLs) or as dissolved solutes resulting in contaminant plumes emanating from the source zone. A large body of research published in Water Resources Research has been devoted to characterizing and understanding processes controlling the transport and fate of these organic contaminants and the effectiveness of natural attenuation, bioremediation, and other remedial technologies. These contributions include studies of NAPL flow, entrapment, and interphase mass transfer that have advanced from the analysis of simple systems with uniform properties and equilibrium contaminant phase partitioning to complex systems with pore-scale and macroscale heterogeneity and rate-limited interphase mass transfer. Understanding of the fate of dissolved organic plumes has advanced from when biodegradation was thought to require oxygen to recognition of the importance of anaerobic biodegradation, multiple redox zones, microbial enzyme kinetics, and mixing of organic contaminants and electron acceptors at plume fringes. Challenges remain in understanding the impacts of physical, chemical, biological, and hydrogeological heterogeneity, pore-scale interactions, and mixing on the fate of organic contaminants. Further effort is needed to successfully incorporate these processes into field-scale predictions of transport and fate. Regulations have greatly reduced the frequency of new point-source contamination problems; however, remediation at many legacy plumes remains challenging. A number of fields of current relevance are benefiting from research advances from point-source contaminant research. These include geologic carbon sequestration, nonpoint-source contamination, aquifer storage and recovery, the fate of contaminants from oil and gas development, and enhanced bioremediation.