Exact solution for a two-phase Stefan problem with variable latent heat and a convective boundary condition at the fixed face

NASA Astrophysics Data System (ADS)

Bollati, Julieta; Tarzia, Domingo A.

2018-04-01

Recently, in Tarzia (Thermal Sci 21A:1-11, 2017) for the classical two-phase Lamé-Clapeyron-Stefan problem an equivalence between the temperature and convective boundary conditions at the fixed face under a certain restriction was obtained. Motivated by this article we study the two-phase Stefan problem for a semi-infinite material with a latent heat defined as a power function of the position and a convective boundary condition at the fixed face. An exact solution is constructed using Kummer functions in case that an inequality for the convective transfer coefficient is satisfied generalizing recent works for the corresponding one-phase free boundary problem. We also consider the limit to our problem when that coefficient goes to infinity obtaining a new free boundary problem, which has been recently studied in Zhou et al. (J Eng Math 2017. https://doi.org/10.1007/s10665-017-9921-y).

Global stability of steady states in the classical Stefan problem for general boundary shapes

PubMed Central

Hadžić, Mahir; Shkoller, Steve

2015-01-01

The classical one-phase Stefan problem (without surface tension) allows for a continuum of steady-state solutions, given by an arbitrary (but sufficiently smooth) domain together with zero temperature. We prove global-in-time stability of such steady states, assuming a sufficient degree of smoothness on the initial domain, but without any a priori restriction on the convexity properties of the initial shape. This is an extension of our previous result (Hadžić & Shkoller 2014 Commun. Pure Appl. Math. 68, 689–757 (doi:10.1002/cpa.21522)) in which we studied nearly spherical shapes. PMID:26261359

[Intellectual exchange between Germany and Latin America: an interview with Stefan Rinke].

PubMed

Rinke, Stefan; da Silva, André Felipe Cândido; Junghans, Miriam; Cavalcanti, Juliana Manzoni; de Muñoz, Pedro Felipe Neves

2014-01-01

Current and former students of the Casa de Oswaldo Cruz/Fiocruz interviewed German historian Stefan Rinke, of the Freie Universität Berlin, who specializes in examining the historical development of Latin America as it fits into the international context. Rinke's work uses dimensions such as economic and diplomatic relations, migratory flows, and ethnic conflict as tools in his analyses of the networks of interdependence that have tied Latin America to Europe and the USA. His lens goes beyond the Latin American continent to approach globalization as a historical process, with national and regional contexts placed within a general framework. In this interview, Rinke talks about his academic career, global and transnational history, and joint projects between Germany and Latin America.

Maxwell-Stefan diffusion: a framework for predicting condensed phase diffusion and phase separation in atmospheric aerosol

NASA Astrophysics Data System (ADS)

Fowler, Kathryn; Connolly, Paul J.; Topping, David O.; O'Meara, Simon

2018-02-01

The composition of atmospheric aerosol particles has been found to influence their micro-physical properties and their interaction with water vapour in the atmosphere. Core-shell models have been used to investigate the relationship between composition, viscosity and equilibration timescales. These models have traditionally relied on the Fickian laws of diffusion with no explicit account of non-ideal interactions. We introduce the Maxwell-Stefan diffusion framework as an alternative method, which explicitly accounts for non-ideal interactions through activity coefficients. e-folding time is the time it takes for the difference in surface and bulk concentration to change by an exponential factor and was used to investigate the interplay between viscosity and solubility and the effect this has on equilibration timescales within individual aerosol particles. The e-folding time was estimated after instantaneous increases in relative humidity to binary systems of water and an organic component. At low water mole fractions, viscous effects were found to dominate mixing. However, at high water mole fractions, equilibration times were more sensitive to a range in solubility, shown through the greater variation in e-folding times. This is the first time the Maxwell-Stefan framework has been applied to an atmospheric aerosol core-shell model and shows that there is a complex interplay between the viscous and solubility effects on aerosol composition that requires further investigation.

Stefan-Maxwell Relations and Heat Flux with Anisotropic Transport Coefficients for Ionized Gases in a Magnetic Field with Application to the Problem of Ambipolar Diffusion

NASA Astrophysics Data System (ADS)

Kolesnichenko, A. V.; Marov, M. Ya.

2018-01-01

The defining relations for the thermodynamic diffusion and heat fluxes in a multicomponent, partially ionized gas mixture in an external electromagnetic field have been obtained by the methods of the kinetic theory. Generalized Stefan-Maxwell relations and algebraic equations for anisotropic transport coefficients (the multicomponent diffusion, thermal diffusion, electric and thermoelectric conductivity coefficients as well as the thermal diffusion ratios) associated with diffusion-thermal processes have been derived. The defining second-order equations are derived by the Chapman-Enskog procedure using Sonine polynomial expansions. The modified Stefan-Maxwell relations are used for the description of ambipolar diffusion in the Earth's ionospheric plasma (in the F region) composed of electrons, ions of many species, and neutral particles in a strong electromagnetic field.

On the Maxwell-Stefan approach to diffusion: a general resolution in the transient regime for one-dimensional systems.

PubMed

Leonardi, Erminia; Angeli, Celestino

2010-01-14

The diffusion process in a multicomponent system can be formulated in a general form by the generalized Maxwell-Stefan equations. This formulation is able to describe the diffusion process in different systems, such as, for instance, bulk diffusion (in the gas, liquid, and solid phase) and diffusion in microporous materials (membranes, zeolites, nanotubes, etc.). The Maxwell-Stefan equations can be solved analytically (only in special cases) or by numerical approaches. Different numerical strategies have been previously presented, but the number of diffusing species is normally restricted, with only few exceptions, to three in bulk diffusion and to two in microporous systems, unless simplifications of the Maxwell-Stefan equations are considered. In the literature, a large effort has been devoted to the derivation of the analytic expression of the elements of the Fick-like diffusion matrix and therefore to the symbolic inversion of a square matrix with dimensions n x n (n being the number of independent components). This step, which can be easily performed for n = 2 and remains reasonable for n = 3, becomes rapidly very complex in problems with a large number of components. This paper addresses the problem of the numerical resolution of the Maxwell-Stefan equations in the transient regime for a one-dimensional system with a generic number of components, avoiding the definition of the analytic expression of the elements of the Fick-like diffusion matrix. To this aim, two approaches have been implemented in a computational code; the first is the simple finite difference second-order accurate in time Crank-Nicolson scheme for which the full mathematical derivation and the relevant final equations are reported. The second is based on the more accurate backward differentiation formulas, BDF, or Gear's method (Shampine, L. F. ; Gear, C. W. SIAM Rev. 1979, 21, 1.), as implemented in the Livermore solver for ordinary differential equations, LSODE (Hindmarsh, A. C. Serial

Maxwell-Stefan diffusion coefficient estimation for ternary systems: an ideal ternary alcohol system.

PubMed

Allie-Ebrahim, Tariq; Zhu, Qingyu; Bräuer, Pierre; Moggridge, Geoff D; D'Agostino, Carmine

2017-06-21

The Maxwell-Stefan model is a popular diffusion model originally developed to model diffusion of gases, which can be considered thermodynamically ideal mixtures, although its application has been extended to model diffusion in non-ideal liquid mixtures as well. A drawback of the model is that it requires the Maxwell-Stefan diffusion coefficients, which are not based on measurable quantities but they have to be estimated. As a result, numerous estimation methods, such as the Darken model, have been proposed to estimate these diffusion coefficients. However, the Darken model was derived, and is only well defined, for binary systems. This model has been extended to ternary systems according to two proposed forms, one by R. Krishna and J. M. van Baten, Ind. Eng. Chem. Res., 2005, 44, 6939-6947 and the other by X. Liu, T. J. H. Vlugt and A. Bardow, Ind. Eng. Chem. Res., 2011, 50, 10350-10358. In this paper, the two forms have been analysed against the ideal ternary system of methanol/butan-1-ol/propan-1-ol and using experimental values of self-diffusion coefficients. In particular, using pulsed gradient stimulated echo nuclear magnetic resonance (PGSTE-NMR) we have measured the self-diffusion coefficients in various methanol/butan-1-ol/propan-1-ol mixtures. The experimental values of self-diffusion coefficients were then used as the input data required for the Darken model. The predictions of the two proposed multicomponent forms of this model were then compared to experimental values of mutual diffusion coefficients for the ideal alcohol ternary system. This experimental-based approach showed that the Liu's model gives better predictions compared to that of Krishna and van Baten, although it was only accurate to within 26%. Nonetheless, the multicomponent Darken model in conjunction with self-diffusion measurements from PGSTE-NMR represents an attractive method for a rapid estimation of mutual diffusion in multicomponent systems, especially when compared to exhaustive

Modeling gas displacement kinetics in coal with Maxwell-Stefan diffusion theory

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

Wei, X.R.; Wang, G.X.; Massarotto, P.

2007-12-15

The kinetics of binary gas counter-diffusion and Darcy flow in a large coal sample were modeled, and the results compared with data from experimental laboratory investigations. The study aimed for a better understanding of the CO{sub 2}-sequestration enhanced coalbed methane (ECBM) recovery process. The transport model used was based on the bidisperse diffusion mechanism and Maxwell-Stefan (MS) diffusion theory. This provides an alternative approach to simulate multicomponent gas diffusion and flow in bulk coals. A series of high-stress core flush tests were performed on a large coal sample sourced from a Bowen Basin coal mine in Queensland, Australia to investigatemore » the kinetics of one gas displacing another. These experimental results were used to derive gas diffusivities, and to examine the predictive capability of the diffusion model. The simulations show good agreements with the displacement experiments revealing that MS diffusion theory is superior for describing diffusion of mixed gases in coals compared with the constant Fick diffusivity model. The optimized effective micropore and macropore diffusivities are comparable with experimental measurements achieved by other researchers.« less

Multicomponent diffusion in molten salt NaF-ZrF4: Dynamical correlations and Maxwell-Stefan diffusivities

NASA Astrophysics Data System (ADS)

Baig, Mohammad Saad; Chakraborty, Brahmananda; Ramaniah, Lavanya M.

2016-05-01

NaF-ZrF4 is used as a waste incinerator and as a coolant in Generation IV reactors.Structural and dynamical properties of molten NaF-ZrF4 system were studied along with Onsagercoefficients and Maxwell-Stefan (MS) Diffusivities applying Green-Kubo formalism and molecular dynamics (MD) simulations. The zirconium ions are found to be 8 fold coordinated with fluoride ions for all temperatures and concentrations. All the diffusive flux correlations show back-scattering. Even though the MS diffusivities are expected to depend very lightly on the composition because of decoupling of thermodynamic factor, the diffusivity ĐNa-F shows interesting behavior with the increase in concentration of ZrF4. This is because of network formation in NaF-ZrF4. Positive entropy constraints have been plotted to authenticate negative diffusivities observed.

Multicomponent diffusion in molten salt LiF-BeF2: Dynamical correlations and Maxwell-Stefan diffusivities

NASA Astrophysics Data System (ADS)

Chakraborty, Brahmananda; Ramaniah, Lavanya M.

2015-06-01

Applying Green-Kubo formalism and equilibrium molecular dynamics (MD) simulations, we have studied the dynamic correlation, Onsager coeeficients and Maxwell-Stefan (MS) Diffusivities of molten salt LiF-BeF2, which is used as coolant in high temperature reactor. All the diffusive flux correlations show back-scattering or cage dynamics which becomes pronouced at higher temperature. Although the MS diffusivities are expected to depend very lightly on the composition due to decoupling of thermodynamic factor, the diffusivity ĐLi-F and ĐBe-F decreases sharply for higher concentration of LiF and BeF2 respectively. Interestingly, all three MS diffusivities have highest magnitude for eutectic mixture at 1000K (except ĐBe-F at lower LiF mole fraction) which is desirable from coolant point of view. Although the diffusivity for positive-positive ion pair is negative it is not in violation of the second law of thermodynamics as it satisfies the non-negative entropic constraints.

Enhanced Recovery in Tight Gas Reservoirs using Maxwell-Stefan Equations

NASA Astrophysics Data System (ADS)

Santiago, C. J. S.; Kantzas, A.

2017-12-01

Due to the steep production decline in unconventional gas reservoirs, enhanced recovery (ER) methods are receiving great attention from the industry. Wet gas or liquid rich reservoirs are the preferred ER candidates due to higher added value from natural gas liquids (NGL) production. ER in these reservoirs has the potential to add reserves by improving desorption and displacement of hydrocarbons through the medium. Nevertheless, analysis of gas transport at length scales of tight reservoirs is complicated because concomitant mechanisms are in place as pressure declines. In addition to viscous and Knudsen diffusion, multicomponent gas modeling includes competitive adsorption and molecular diffusion effects. Most models developed to address these mechanisms involve single component or binary mixtures. In this study, ER by gas injection is investigated in multicomponent (C1, C2, C3 and C4+, CO2 and N2) wet gas reservoirs. The competing effects of Knudsen and molecular diffusion are incorporated by using Maxwell-Stefan equations and the Dusty-Gas approach. This model was selected due to its superior properties on representing the physics of multicomponent gas flow, as demonstrated during the presented model validation. Sensitivity studies to evaluate adsorption, reservoir permeability and gas type effects are performed. The importance of competitive adsorption on production and displacement times is demonstrated. In the absence of adsorption, chromatographic separation is negligible. Production is merely dictated by competing effects between molecular and Knudsen diffusion. Displacement fronts travel rapidly across the medium. When adsorption effects are included, molecules with lower affinity to the adsorption sites will be produced faster. If the injected gas is inert (N2), an increase in heavier fraction composition occurs in the medium. During injection of adsorbing gases (CH4 and CO2), competitive adsorption effects will contribute to improved recovery of heavier

Continuum Model for Decontamination of Chemical Warfare Agent from a Rubbery Polymer using the Maxwell-Stefan Formulation

NASA Astrophysics Data System (ADS)

Varady, Mark; Bringuier, Stefan; Pearl, Thomas; Stevenson, Shawn; Mantooth, Brent

Decontamination of polymers exposed to chemical warfare agents (CWA) often proceeds by application of a liquid solution. Absorption of some decontaminant components proceed concurrently with extraction of the CWA, resulting in multicomponent diffusion in the polymer. In this work, the Maxwell-Stefan equations were used with the Flory-Huggins model of species activity to mathematically describe the transport of two species within a polymer. This model was used to predict the extraction of the nerve agent O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate (VX) from a silicone elastomer into both water and methanol. Comparisons with experimental results show good agreement with minimal fitting of model parameters from pure component uptake data. Reaction of the extracted VX with sodium hydroxide in the liquid-phase was also modeled and used to predict the overall rate of destruction of VX. Although the reaction proceeds more slowly in the methanol-based solution compared to the aqueous solution, the extraction rate is faster due to increasing VX mobility as methanol absorbs into the silicone, resulting in an overall faster rate of VX destruction.

Multicomponent diffusion in molten salt LiF-BeF{sub 2}: Dynamical correlations and Maxwell–Stefan diffusivities

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

Chakraborty, Brahmananda, E-mail: brahma@barc.gov.in; Ramaniah, Lavanya M.

2015-06-24

Applying Green–Kubo formalism and equilibrium molecular dynamics (MD) simulations, we have studied the dynamic correlation, Onsager coeeficients and Maxwell–Stefan (MS) Diffusivities of molten salt LiF-BeF{sub 2}, which is used as coolant in high temperature reactor. All the diffusive flux correlations show back-scattering or cage dynamics which becomes pronouced at higher temperature. Although the MS diffusivities are expected to depend very lightly on the composition due to decoupling of thermodynamic factor, the diffusivity Đ{sub Li-F} and Đ{sub Be-F} decreases sharply for higher concentration of LiF and BeF{sub 2} respectively. Interestingly, all three MS diffusivities have highest magnitude for eutectic mixture atmore » 1000K (except Đ{sub Be-F} at lower LiF mole fraction) which is desirable from coolant point of view. Although the diffusivity for positive-positive ion pair is negative it is not in violation of the second law of thermodynamics as it satisfies the non-negative entropic constraints.« less

Maxwell-Stefan diffusion and dynamical correlation in molten LiF-KF: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Jain, Richa Naja; Chakraborty, Brahmananda; Ramaniah, Lavanya M.

2016-05-01

In this work our main objective is to compute Dynamical correlations, Onsager coefficients and Maxwell-Stefan (MS) diffusivities for molten salt LiF-KF mixture at various thermodynamic states through Green-Kubo formalism for the first time. The equilibrium molecular dynamics (MD) simulations were performed using BHM potential for LiF-KF mixture. The velocity autocorrelations functions involving Li ions reflect the endurance of cage dynamics or backscattering with temperature. The magnitude of Onsager coefficients for all pairs increases with increase in temperature. Interestingly most of the Onsager coefficients has almost maximum magnitude at the eutectic composition indicating the most dynamic character of the eutectic mixture. MS diffusivity hence diffusion for all ion pairs increases in the system with increasing temperature. Smooth variation of the diffusivity values denies any network formation in the mixture. Also, the striking feature is the noticeable concentration dependence of MS diffusivity between cation-cation pair, ĐLi-K which remains negative for most of the concentration range but changes sign to become positive for higher LiF concentration. The negative MS diffusivity is acceptable as it satisfies the non-negative entropy constraint governed by 2nd law of thermodynamics. This high diffusivity also vouches the candidature of molten salt as a coolant.

Cognitive group therapy for depressive students: The case study

PubMed Central

Tiuraniemi, Juhani; Korhola, Jarno

2009-01-01

The aims of this study were to assess whether a course of cognitive group therapy could help depressed students and to assess whether assimilation analysis offers a useful way of analysing students' progress through therapy. “Johanna” was a patient in a group that was designed for depressive students who had difficulties with their studies. The assimilation of Johanna's problematic experience progressed as the meetings continued from level one (unpleasant thoughts) to level six (solving the problem). Johanna's problematic experience manifested itself as severe and excessive criticism towards herself and her study performance. As the group meetings progressed, Johanna found a new kind of tolerance that increased her determination and assertiveness regarding the studies. The dialogical structure of Johanna's problematic experience changed: she found hope and she was more assertive after the process. The results indicated that this kind of psycho-educational group therapy was an effective method for treating depression. The assimilation analysis offered a useful way of analysing the therapy process. PMID:20523883

The Stefan problem of solidification of ternary systems in the presence of moving phase transition regions

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

Alexandrov, D. V., E-mail: Dmitri.Alexandrov@usu.ru; Ivanov, A. A.

2009-05-15

The process of solidification of ternary systems in the presence of moving phase transition regions has been investigated theoretically in terms of the nonlinear equation of the liquidus surface. A mathematical model is developed and an approximate analytical solution to the Stefan problem is constructed for a linear temperature profile in two-phase zones. The temperature and impurity concentration distributions are determined, the solid-phase fractions in the phase transition regions are obtained, and the laws of motion of their boundaries are established. It is demonstrated that all boundaries move in accordance with the laws of direct proportionality to the square rootmore » of time, which is a general property of self-similar processes. It is substantiated that the concentration of an impurity of the substance undergoing a phase transition only in the cotectic zone increases in this zone and decreases in the main two-phase zone in which the other component of the substance undergoes a phase transition. In the process, the concentration reaches a maximum at the interface between the main two-phase zone and the cotectic two-phase zone. The revealed laws of motion of the outer boundaries of the entire phase transition region do not depend on the amount of the components under consideration and hold true for crystallization of a multicomponent system.« less

Stefan blowing effects on MHD bioconvection flow of a nanofluid in the presence of gyrotactic microorganisms with active and passive nanoparticles flux

NASA Astrophysics Data System (ADS)

Giri, Shib Sankar; Das, Kalidas; Kundu, Prabir Kumar

2017-02-01

The present paper investigates the effect of Stefan blowing on the hydro-magnetic bioconvection of a water-based nanofluid flow containing gyrotactic microorganisms through a permeable surface. Also we studied both actively and passively the controlled flux of nanoparticles and the effect of a surface slip at the wall. We adopt a similarity approach to reduce the leading partial differential equations into ordinary differential equations along with two separate boundary conditions (active and passive) and solve the resulting equations numerically by employing the RK-4 method through the shooting technique to perform the flow analysis. Discussions on the effect of emerging flow parameter on the flow characteristic are made properly through graphs and charts. We observed that the effects of the traditional Lewis number and suction/blowing parameter on temperature distribution and microorganism concentration are converse to each other. A fair result comparison of the present paper with formerly obtained results is given.

A high brightness proton injector for the Tandetron accelerator at Jožef Stefan Institute

NASA Astrophysics Data System (ADS)

Pelicon, Primož; Podaru, Nicolae C.; Vavpetič, Primož; Jeromel, Luka; Ogrinc Potocnik, Nina; Ondračka, Simon; Gottdang, Andreas; Mous, Dirk J. M.

2014-08-01

Jožef Stefan Institute recently commissioned a high brightness H- ion beam injection system for its existing tandem accelerator facility. Custom developed by High Voltage Engineering Europa, the multicusp ion source has been tuned to deliver at the entrance of the Tandetron™ accelerator H- ion beams with a measured brightness of 17.1 A m-2 rad-2 eV-1 at 170 μA, equivalent to an energy normalized beam emittance of 0.767 π mm mrad MeV1/2. Upgrading the accelerator facility with the new injection system provides two main advantages. First, the high brightness of the new ion source enables the reduction of object slit aperture and the reduction of acceptance angle at the nuclear microprobe, resulting in a reduced beam size at selected beam intensity, which significantly improves the probe resolution for micro-PIXE applications. Secondly, the upgrade strongly enhances the accelerator up-time since H and He beams are produced by independent ion sources, introducing a constant availability of 3He beam for fusion-related research with NRA. The ion beam particle losses and ion beam emittance growth imply that the aforementioned beam brightness is reduced by transport through the ion optical system. To obtain quantitative information on the available brightness at the high-energy side of the accelerator, the proton beam brightness is determined in the nuclear microprobe beamline. Based on the experience obtained during the first months of operation for micro-PIXE applications, further necessary steps are indicated to obtain optimal coupling of the new ion source with the accelerator to increase the normalized high-energy proton beam brightness at the JSI microprobe, currently at 14 A m-2 rad-2 eV-1, with the output current at 18% of its available maximum.

Determination of the phase transition in Pb{sub 0.88}Ln{sub 0.08}Ti{sub 0.98}Mn{sub 0.02}O{sub 3} (Ln=La, Sm, Eu) piezoceramics based on the Stefan-Boltzmann law

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

Suaste, Ernesto; Castillo, Victor; Gonzalez, Ruben

2004-07-15

A method for determination of the phase transition in piezoelectric ceramic based on the relationship expressed by the Stefan-Boltzmann law is reported, i.e., by means of the radiation that the piezoelectric ceramic emits when it is subjected to different temperatures. The experiment is performed in piezoelectric ceramic based on PbTiO{sub 3} modified by the partial substitution of rare earths for Pb in the Pb{sub 0.88}(Ln){sub 0.08}Ti{sub 0.98}Mn{sub 0.02}O{sub 3} system (Ln=La, Sm, Eu). From the measured emitted radiation, the value of the emissivity is calculated for each type of piezoelectric ceramic.

Sign Crossover in All Maxwell-Stefan Diffusivities for Molten Salt LiF-BeF2: A Molecular Dynamics Study.

PubMed

Chakraborty, Brahmananda

2015-08-20

Applying Green-Kubo formalism and equilibrium molecular dynamics (MD) simulations, we have studied for the first time the dynamic correlation, Onsager coefficients, and Maxwell-Stefan (MS) diffusivities of molten salt LiF-BeF2, which is a potential candidate for a coolant in a high temperature reactor. We observe an unusual composition dependence and strikingly a crossover in sign for all the MS diffusivities at a composition of around 7% of LiF where the MS diffusivity between cation-anion pair (Đ(BeF) and Đ(LiF)) jumps from positive to negative value while the MS diffusivity between cation-cation pair (Đ(LiBe)) becomes positive from a negative value. Even though the negative MS diffusivities have been observed for electrolyte solutions between cation-cation pair, here we report negative MS diffusivity between cation-anion pair where Đ(BeF) shows a sharp rise around 66% of BeF2, reaches maximum value at 70% of BeF2, and then decreases almost exponentially with a sign change for BeF2 around 93%. For low mole fraction of LiF, Đ(BeF) follows the Debye-Huckel theory and rises with the square root of LiF mole fraction similar to the MS diffusivity between cation-anion pair in aqueous solution of electrolyte salt. Negative MS diffusivities while unusual are, however, shown to satisfy the non-negative entropy constraints at all thermodynamic states as required by the second law of thermodynamics. We have established a strong correlation between the structure and dynamics and predict that the formation of flouride polyanion network between Be and F ions and coulomb interaction is responsible for sharp variation of the MS diffusivities which controls the multicomponent diffusion phenomenon in LiF-BeF2 which has a strong impact on the performance of the reactor.

Approximation and Numerical Analysis of Nonlinear Equations of Evolution.

DTIC Science & Technology

1980-01-31

dominant convective terms, or Stefan type problems such as the flow of fluids through porous media or the melting and freezing of ice. Such problems...means of formulating time-dependent Stefan problems was initiated. Classes of problems considered here include the one-phase and two-phase Stefan ...some new numerical methods were 2 developed for two dimensional, two-phase Stefan problems with time dependent boundary conditions. A variety of example

Diet and Cancer Prevention: Chewing on the Human Complexities | Division of Cancer Prevention

Cancer.gov

Speaker Johanna W. Lampe, PhD, RD Research Professor University of Washington Full Member and Associate Division Director Cancer Prevention Program Public Health Sciences Division Fred Hutchinson Cancer Research Center Seattle, WA |

Conceptual Design of a Clinical BNCT Beam in an Adjacent Dry Cell of the Jozef Stefan Institute TRIGA Reactor

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

Maucec, Marko

2000-11-15

The MCNP4B Monte Carlo transport code is used in a feasibility study of the epithermal neutron boron neutron capture therapy facility in the thermalizing column of the 250-kW TRIGA Mark II reactor at the Jozef Stefan Institute (JSI). To boost the epithermal neutron flux at the reference irradiation point, the efficiency of a fission plate with almost 1.5 kg of 20% enriched uranium and 2.3 kW of thermal power is investigated. With the same purpose in mind, the TRIGA reactor core setup is optimized, and standard fresh fuel elements are concentrated partly in the outermost ring of the core. Further,more » a detailed parametric study of the materials and dimensions for all the relevant parts of the irradiation facility is carried out. Some of the standard epithermal neutron filter/moderator materials, as well as 'pressed-only' low-density Al{sub 2}O{sub 3} and AlF{sub 3}, are considered. The proposed version of the BNCT facility, with PbF{sub 2} as the epithermal neutron filter/moderator, provides an epithermal neutron flux of {approx}1.1 x 10{sup 9} n/cm{sup 2}.s, thus enabling patient irradiation times of <60 min. With reasonably low fast neutron and photon contamination ([overdot]D{sub nfast}/{phi}{sub epi} < 5 x 10{sup -13} Gy.cm{sup 2}/n and [overdot]D{sub {gamma}} /{phi}{sub epi} < 3 x 10{sup -13} Gy.cm{sup 2}/n), the in-air performances of the proposed beam are comparable to all existing epithermal BNCT facilities. The design presents an equally efficient alternative to the BNCT beams in TRIGA reactor thermal columns that are more commonly applied. The cavity of the dry cell, a former JSI TRIGA reactor spent-fuel storage facility, adjacent to the thermalizing column, could rather easily be rearranged into a suitable patient treatment room, which would substantially decrease the overall developmental costs.« less

Brookhaven Women in Science Lecture

ScienceCinema

Johanna Levelt Sengers

2017-12-09

Sponsored by Brookhaven Women in Science (BWIS), Johanna Levelt Sengers, Scientist Emeritus at the National Institute of Standards & Technology (NIST), presents a talk titled "The World's Science Academies Address the Under-Representation of Women in Science and Technology."

Erratum: Erratum to: The Quadrennial Ozone Symposium 2016

NASA Astrophysics Data System (ADS)

Godin-Beekmann, Sophie; Petropavlovskikh, Irina; Reis, Stefan; Newman, Paul; Steinbrecht, Wolfgang; Rex, Markus; Santee, Michelle L.; Eckman, Richard S.; Zheng, Xiangdong; Tully, Matthew B.; Stevenson, David S.; Young, Paul; Pyle, John; Weber, Mark; Tamminen, Johanna; Mills, Gina; Bais, Alkiviadis F.; Heaviside, Clare; Zerefos, Christos

2018-03-01

The Quadrennial Ozone Symposium 2016 Sophie GODIN-BEEKMANN*1, Irina PETROPAVLOVSKIKH2, Stefan REIS3,20, Paul NEWMAN4, Wolfgang STEINBRECHT5, Markus REX6, Michelle L. SANTEE7, Richard S. ECKMAN8, Xiangdong ZHENG9, Matthew B. TULLY10, David S. STEVENSON11, Paul YOUNG12, John PYLE13, Mark WEBER14, Johanna TAMMINEN15, Gina MILLS16, Alkiviadis F. BAIS17, Clare HEAVISIDE18, and Christos ZEREFOS19 1 Observatoire de Versailles Saint-Quentin en Yvelines, Université de Versailles Saint-Quentin-en-Yvelines, CNRS, 78280 Guyancourt, France 2 CIRES, University of Colorado, Boulder, CO 80309, USA 3 NERC Centre for Ecology & Hydrology, Edinburgh EH26 0QB, UK 4 Goddard Space Flight Center, NASA, Greenbelt, MD 20771, USA 5 Hohenpeissenberg Meteorological Observatory, Deutscher Wetterdienst, 82383 Hohenpeissenberg, Germany 6 Alfred Wegener Institute, 14401 Potsdam, Germany 7 Jet Propulsion Laboratory, California Institute of Technology, CA 91109, USA 8 NASA Headquarters, Earth Science Division, Washington, DC, USA 9 Chinese Academy of Meteorological Sciences, Beijing, 100081, China 10 Bureau of Meteorology, Melbourne, Victoria 3001, Australia 11 University of Edinburgh, School of GeoSciences, Edinburgh EH9 3FE, UK 12 Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK 13 University of Cambridge, Department of Chemistry, Cambridge CB2 1EW, UK 14 University of Bremen, Institute of Environmental Physics, 28359 Bremen, Germany 15 Finnish Meteorological Institute, Earth Observation, FI-00101 Helsinki, Finland 16 NERC Centre for Ecology and Hydrology, Bangor, Gwynedd LL57 2UW, Wales, UK 17 Aristotle University of Thessaloniki, Thessaloniki, Greece 18 Public Health England, Centre for Radiation, Chemical and Environmental Hazards, London, UK 19 Research Center for Atmospheric Physics & Climatology, Academy of Athens, Athens 10680, Greece 20 University of Exeter Medical School, Truro TR1 3HD, UK

Mathematical modeling of radiative-conductive heat transfer in semitransparent medium with phase change

NASA Astrophysics Data System (ADS)

Savvinova, Nadezhda A.; Sleptsov, Semen D.; Rubtsov, Nikolai A.

2017-11-01

A mathematical phase change model is a formulation of the Stefan problem. Various formulations of the Stefan problem modeling of radiative-conductive heat transfer during melting or solidification of a semitransparent material are presented. Analysis of numerical results show that the radiative heat transfer has a significant effect on temperature distributions during melting (solidification) of the semitransparent material. In this paper conditions for application of various statements of the Stefan problem are analyzed.

Analysis of the Performance of Heat Pipes and Phase-Change Materials with Multiple Localized Heat Sources for Space Applications

DTIC Science & Technology

1989-05-01

NUMERICAL ANALYSIS OF STEFAN PROBLEMS FOR GENERALIZED MULTI- DIMENSIONAL PHASE-CHANGE STRUCTURES USING THE ENTHALPY TRANSFORMING MODEL 4.1 Summary...equation St Stefan number, cs(Tm-Tw)/H or cs(Tm-Ti)/H s circumferential distance coordinate, m, Section III s dimensionless interface position along...fluid, kg/m 3 0 viscous dissipation term in the energy eqn. (1.4), Section I; dummy variable, Section IV r dimensionless time, ta/L 2 a Stefan -Boltzmann

SLAC All Access: X-ray Microscope

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

Nelson, Johanna; Liu, Yijin

2012-08-14

SLAC physicists Johanna Nelson and Yijin Liu give a brief overview of the X-ray microscope at the Stanford Synchrotron Radiation Lightsource (SSRL) that is helping improve rechargeable-battery technology by letting researchers peek into the inner workings of batteries as they operate.

SLAC All Access: X-ray Microscope

ScienceCinema

Nelson, Johanna; Liu, Yijin

2018-01-16

SLAC physicists Johanna Nelson and Yijin Liu give a brief overview of the X-ray microscope at the Stanford Synchrotron Radiation Lightsource (SSRL) that is helping improve rechargeable-battery technology by letting researchers peek into the inner workings of batteries as they operate.

Workforce Preparation in a Global Context. Occasional Papers 8.

ERIC Educational Resources Information Center

Lasonen, Johanna, Ed.

This document contains 21 papers and an introduction on work force preparation in a global context. The following papers are included: "Introduction" (Johanna Lasonen); "Access of Girls and Women to Vocational Education: Implications for the Workplace in Swaziland" (Comfort B. S. Mndebele); "Intersectoral Approaches to…

Contemporary Issues of Occupational Education in Finland.

ERIC Educational Resources Information Center

Lasonen, Johanna, Ed.; Stenstrom, Marja-Leena, Ed.

This book contains 28 papers about the current status of occupational education in Finland, with special emphasis on context factors, structural and pedagogical reform, and quality management. The following papers are included: "Introduction of Educational Structure in Finland" (Johanna Lasonen, Marja-Leena Stenstrom); "Vocational…

Software Development: A Product Life-Cycle Perspective

DTIC Science & Technology

1990-05-01

management came from these magazines and journals: Journal of Advertising Research , Business Marketing, Journal of Systems Manaament, nural Marketing...Johanna. "Price is More Sensitive." Software Magazine, March 1988, 44. Andrews, Kirby. "Communications Imperatives for New Products." Journal of Advertising Research , October

Strategies for Reforming Workforce Preparation Programs in Europe

ERIC Educational Resources Information Center

Stenstrom, Marja-Leena; Lasonen, Johanna

2004-01-01

The Post-16 Strategies project coordinated by Dr. Johanna Lasonen from 1996 to 1998 was chiefly concerned with four post-16 education strategies: (1) "vocational enhancement"; (2) "mutual enrichment"; (3) "linkages;" and (4) "unification." These four strategies to promote parity of esteem between vocational…

Lives within lives: hidden fungal biodiversity within insects, mammals, mites, and plants

USDA-ARS?s Scientific Manuscript database

Nothing is sterile. Insects, mammals, mites, and plants, all hide a vast fungal biodiversity whose role is for the most part unknown. From the work of Lynn Margulies, Miriam Rothschild and Johanna Westerdijk, we have gained a better understanding of how microbial associations pervade living systems ...

75 FR 19952 - Proposed Agency Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-16

..., expenditures, and results, to ensure that program funds are being used appropriately, effectively and expeditiously (especially important for Recovery Act funds); (5) Annual Estimated Number of Respondents: 56; (6... Independence and Security Act (EISA), Pub. L. 110-140. Issued in Washington, DC, on April 12, 2010. Johanna...

Reflections on Post-16 Strategies in European Countries. Interim Report of the Leonardo da Vinci/Multiplier Effect Project III.3.a. Priority 2: Forging Links between Educational Establishments and Enterprises (1997-2000) ID 27009. Working Papers, No. 9.

ERIC Educational Resources Information Center

Stenstrom, Marja-Leena, Ed.

This four-part publication contains 19 papers on educational practices and promises for post-16 education in European countries. Part I, the introduction, contains these three papers: "Sharpening Post-16 Education Strategies: Building on the Results of the Previous Projects" (Johanna Lasonen); "'Parity of Esteem' and 'Integrated…

Monetary and Fiscal Policy Interactions in the Euro Area

DTIC Science & Technology

2004-03-01

Balassa - Samuelson -Effekt, Nr. 3/2002, erschienen in: Stefan Reitz (Hg.): Theoretische und wirtschaftspolitische Aspekte der internatio- nalen Integration...156, 2000, S. 646-660. Friihere Diskussionsbeitriige zur Finanzwissenschaft Josten, Stefan, Crime, Inequality, and Economic Growth. A Classical Argument

Of Big Hegemonies and Little Tigers: Ecocentrism and Environmental Justice

ERIC Educational Resources Information Center

Kopnina, Helen

2016-01-01

Stefan Bengtsson's commentary about policy hegemony discusses the alternative discourses of socialism, nationalism, and globalism. However, Stefan does not adequately demonstrate how these discourses can overcome the Dominant Western Worldview (DWW), which is imbued with anthropocentrism. It will be argued here that most policy choices promoting…

Heating Parameter Estimation Using Coaxial Thermocouple Gages in Wind Tunnel Test Articles.

DTIC Science & Technology

1984-12-01

Attack a Emissivity G Parameter Vector Pn Measurement Vector at nth Time Point p Density 0 Stefan-Boltzmann Constant 6 Transition Matrix APc Scaling...for. The radiation is modeled using the Stefan-Boltzmann Law, q = 60(U 4 - U, 4 ) (A-9) where 8 radiative emissivity a Stefan-Bol tzmann constant U...w00 I- 000 0 0111c :0 i zZ Z-4lwr I- E . - t J K - IL HHO "W 6i 0WZWZWO&000OW *0 . 0 - .- - -4 4 1"- 1 Lii w LiiU Li LI Li Lij Liw w ~ o 0 0wm ~wW6~w d

Family Learning Nights Raise Scientific Interest

ERIC Educational Resources Information Center

Greygoose, Kirsten

2014-01-01

How can pupils and parents be engaged in science? This author describes holding an astronomy evening with Dr. Johanna Jarvis to coincide with the BBC's "Stargazing Live." The author briefly shares an account of the success of this first of many evening events. Engaging pupils in science at an early age has the potential to change social…

Global Phenomena from Local Rules: Peer-to-Peer Networks and Crystal Steps

DTIC Science & Technology

2007-01-01

2005. http://www.cachelogic.com, August 2005. [43] Vern Paxson and Sally Floyd. Wide area traffic: The failure of poisson modeling. IEEE/ACM...International Workshop on Peer-to-Peer Systems (IPTPS), Cambridge, Massachusetts, USA, March 2002. [45] Stefan Saroiu, Krishna P. Gummadi, Richard J...Implementation (ODSI), Boston, Mas- sachusetts, USA, December 2002. [46] Stefan Saroiu, P. Krishna Gummadi, and Steven D. Gribble. A measurement study of peer

Experimental Investigation of Irregular Wave Cancellation Using a Cycloidal Wave Energy Converter

DTIC Science & Technology

2012-07-01

83388 EXPERIMENTAL INVESTIGATION OF IRREGULAR WAVE CANCELLATION USING A CYCLOIDAL WAVE ENERGY CONVERTER Stefan G. Siegel∗ Department of Aeronautics...United States Air Force Academy Air Force Academy, Colorado, 80840 USA Email: stefan @siegels.us Casey Fagley Department of Aeronautics United States Air...would like to acknowledge fruitful discussion with Dr. Jürgen Seidel and Dr. Tiger Jeans. This material is based upon activities supported by the

Exploiting Inhibitory Siglecs to Combat Food Allergies

DTIC Science & Technology

2017-10-01

project including mouse handling, liposome preparation, and in vitro assays, such as ELISAs . Shiteng and Kevin Worrell participated in groups...h 2. She also contributed by running some ELISA experiments. Funding Support: N/A Name: Kelly Orgel Project Role: Graduate Student (UNC...flow cytometry, and ELISA . Kelly performed the human CD33 basophil assays as well. Funding Support: N/A Name: Johanna Smeekens, PhD Project

Trapping of Li(+) Ions by [ThFn](4-n) Clusters Leading to Oscillating Maxwell-Stefan Diffusivity in the Molten Salt LiF-ThF4.

PubMed

Chakraborty, Brahmananda; Kidwai, Sharif; Ramaniah, Lavanya M

2016-08-18

A molten salt mixture of lithium fluoride and thorium fluoride (LiF-ThF4) serves as a fuel as well as a coolant in the most sophisticated molten salt reactor (MSR). Here, we report for the first time dynamic correlations, Onsager coefficients, Maxwell-Stefan (MS) diffusivities, and the concentration dependence of density and enthalpy of the molten salt mixture LiF-ThF4 at 1200 K in the composition range of 2-45% ThF4 and also at eutectic composition in the temperature range of 1123-1600 K using Green-Kubo formalism and equilibrium molecular dynamics simulations. We have observed an interesting oscillating pattern for the MS diffusivity for the cation-cation pair, in which ĐLi-Th oscillates between positive and negative values with the amplitude of the oscillation reducing as the system becomes rich in ThF4. Through the velocity autocorrelation function, vibrational density of states, radial distribution function analysis, and structural snapshots, we establish an interplay between the local structure and multicomponent dynamics and predict that formation of negatively charged [ThFn](4-n) clusters at a higher ThF4 mole % makes positively charged Li(+) ions oscillate between different clusters, with their range of motion reducing as the number of [ThFn](4-n) clusters increases, and finally Li(+) ions almost get trapped at a higher ThF4% when the electrostatic force on Li(+) exerted by various surrounding clusters gets balanced. Although reports on variations of density and enthalpy with temperature exist in the literature, for the first time we report variations of the density and enthalpy of LiF-ThF4 with the concentration of ThF4 (mole %) and fit them with the square root function of ThF4 concentration, which will be very useful for experimentalists to obtain data over a range of concentrations from fitting the formula for design purposes. The formation of [ThFn](4-n) clusters and the reduction in the diffusivity of the ions at a higher ThF4% may limit the

RENDEZVOUS: Self-Organizing Services in an Active Network

DTIC Science & Technology

2004-02-01

http://www.cs.washington.edu/research/networking/ants/, and http://www.cs.utah.edu/flux/janos/ants.html, 2001. [2] Krishna P. Gummadi, “King...Proceedings of the Tenth ACM SIGOPS European Workshop, September 2002. [9] Stefan Saroiu, P. Krishna Gummadi, Steven D. Gribble: A Measurement Study...Davis, Eric Lemar, and Brian Bershad. “Migration for Pervasive Applications.” Submitted to OSDI, June 2002. Gummadi, P. Krishna , Stefan Saroiu, and

Computational Fluid Dynamic Solutions of Optimized Heat Shields Designed for Earth Entry

DTIC Science & Technology

2010-01-01

domain ρ = Density (kg/m3) σ = Stefan Boltzmann constant τ = Shear stress tensor τT−V = T-V relaxation time τe−V = e-V relaxation time xi φ = Sweep angle...Vehicle DES = Differential evolutionary Scheme DOR = Design Optimization Tools DPLR = Data Parallel Line Relaxation GSLR = Gauss- Seidel Line... Stefan - Boltzmann constant. This model provides accurate heating predictions, especially for the non-ablating heat-shields explored in this work. Various

Finite-Size Effects of Binary Mutual Diffusion Coefficients from Molecular Dynamics

PubMed Central

2018-01-01

Molecular dynamics simulations were performed for the prediction of the finite-size effects of Maxwell-Stefan diffusion coefficients of molecular mixtures and a wide variety of binary Lennard–Jones systems. A strong dependency of computed diffusivities on the system size was observed. Computed diffusivities were found to increase with the number of molecules. We propose a correction for the extrapolation of Maxwell–Stefan diffusion coefficients to the thermodynamic limit, based on the study by Yeh and Hummer (J. Phys. Chem. B, 2004, 108, 15873−15879). The proposed correction is a function of the viscosity of the system, the size of the simulation box, and the thermodynamic factor, which is a measure for the nonideality of the mixture. Verification is carried out for more than 200 distinct binary Lennard–Jones systems, as well as 9 binary systems of methanol, water, ethanol, acetone, methylamine, and carbon tetrachloride. Significant deviations between finite-size Maxwell–Stefan diffusivities and the corresponding diffusivities at the thermodynamic limit were found for mixtures close to demixing. In these cases, the finite-size correction can be even larger than the simulated (finite-size) Maxwell–Stefan diffusivity. Our results show that considering these finite-size effects is crucial and that the suggested correction allows for reliable computations. PMID:29664633

A Responsible De-Identification Of The Real Data Corpus: Building A Framework For PII Management

DTIC Science & Technology

2016-09-01

MANAGEMENT by Johanna An September 2016 Thesis Co-Advisors: Michael R. McCarrin Dorothy E. Denning Approved for public release. Distribution is unlimited. THIS...and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202–4302, and to the Office of Management and Budget, Paperwork Reduction Project...2016 to 9-10-2016 4. TITLE AND SUBTITLE ARESPONSIBLEDE-IDENTIFICATIONOFTHEREALDATACORPUS:BUILDING A FRAMEWORK FOR PII MANAGEMENT 5. FUNDING NUMBERS 6

[Medical institutions and physicians in the district of Garwolin during the period the II Republic of Poland].

PubMed

Kocon, T

2001-01-01

Presentation of the District Hospital in Garwolin and the Regional Council Hospital in Maciejowice. List of names of physicians working in hospitals, public health centers and sick-fund centers. Biographies of physicians proceeding from the district and related somehow with it during the period of the II Republic, namely: Feliks Malinowski, Czesłow Bogucki, Józef Kenig, Stefan Niziński, Stefan Soszka, Władysław Galasiński, Józef Mazurek.

Solid–Liquid Phase Change Driven by Internal Heat Generation

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

John Crepeau; Ali s. Siahpush

2012-07-01

This article presents results of solid-liquid phase change, the Stefan Problem, where melting is driven internal heat generation, in a cylindrical geometry. The comparison between a quasi-static analytical solution for Stefan numbers less than one and numerical solutions shows good agreement. The computational results of phase change with internal heat generation show how convection cells form in the liquid region. A scale analysis of the same problem shows four distinct regions of the melting process.

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

Gim, Yongwan; Kim, Wontae, E-mail: yongwan89@sogang.ac.kr, E-mail: wtkim@sogang.ac.kr

In warm inflation scenarios, radiation always exists, so that the radiation energy density is also assumed to be finite when inflation starts. To find out the origin of the non-vanishing initial radiation energy density, we revisit thermodynamic analysis for a warm inflation model and then derive an effective Stefan-Boltzmann law which is commensurate with the temperature-dependent effective potential by taking into account the non-vanishing trace of the total energy-momentum tensors. The effective Stefan-Boltzmann law shows that the zero energy density for radiation at the Grand Unification epoch increases until the inflation starts and it becomes eventually finite at the initialmore » stage of warm inflation. By using the above effective Stefan-Boltzmann law, we also study the cosmological scalar perturbation, and obtain the sufficient radiation energy density in order for GUT baryogenesis at the end of inflation.« less

Dendrite-Free Electrodeposition and Reoxidation of Lithium-Sodium Alloy for Metal-Anode Battery

DTIC Science & Technology

2011-11-01

Dendrite-Free Electrodeposition and Reoxidation of Lithium-Sodium Alloy for Metal-Anode Battery Johanna K. Star 1 , Yi Ding 2 , and Paul A. Kohl ,1, * 1...Journal Article 3. DATES COVERED 01-11-2011 to 01-11-2011 4. TITLE AND SUBTITLE DENDRITE-FREE ELECTRODEPOSITION AND REOXIDATION OF LITHIUM-SODIUM...Results and Discussion The initial ionic liquid selection was driven by the need to electrodeposit sodium and lithium from the same electrolyte

3D Navier-Stokes Flow Analysis for Shared and Distributed Memory MIMD Computers

DTIC Science & Technology

1992-09-15

arithmetical averaged density or Stefan -Boltzmann constant (= 5.67032 x 10-8 ) Oai+1/2 intermediate term for Harten-Yee fluxes - k, O’ constants for k...system of algebraic equations. These equations I are solved using point Gauss- Seidel relaxation. This relaxation scheme is modified to be a lower-upper...interaction of the radiation with the gas. The radiative heat flux per unit area is then I = -(T [EwT - awTdb] (19) Here a is the Stefan Boltzmann

Laser-Neuron Interaction with Femtosecond Beat-Modulated 800-1200 nm Photon Beams, as the Treatment of Brain Cancer Tissue. Laser Neurophysics

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2011-03-01

I propose a novel mechanism for the brain cancer tissue treatment: nonlinear interaction of ultrashort pulses of beat-photon, (ω1 -- ω2) , or double-photon, (ω1 +ω2) , beams with the cancer tissue. The multiphoton scattering is described via photon diffusion equation. The open-scull cerebral tissue can be irradiated with the beat-modulated photon pulses with the laser irradiances in the range of a few mW/cm2 , and repetition rate of a few 100s Hz generated in the beat-wave driven free electron laser. V. Stefan, B. I. Cohen, and C. Joshi, Nonlinear Mixing of Electromagnetic Waves in PlasmasScience 27 January 1989: V. Alexander Stefan, Genomic Medical Physics: A New Physics in the Making, (S-U-Press, 2008).} This highly accurate cancer tissue ablation removal may prove to be an efficient method for the treatment of brain cancer. Work supported in part by Nikola Tesla Laboratories (Stefan University), La Jolla, CA.

Program 6 Technical Interchange Meeting Proceedings

DTIC Science & Technology

1992-10-01

Buteau PRC (703)556-1355 Gary R. Dolson PRC (703) 5561859 David J. Gray Sterling (315)336-0500 Noreen S. Heyda Harris (407)984-6384 Jay Jesse GTE (719)570...Reed Sterling John Sautter Sterling (315)336-0500 Kevin Sculley PRC (402)291-5533 Stefan Shrier MRJ (703)934-9249 Peter Soliz Orion (505)262-2260...4730 Howard A. Melching GTE (719)570-8898 Noreen S. Heyda Harris (407)984-6384 Jonathan H. Reed Harris (407)984-6008 Stefan Shrier MRJ (703) 934-9249

Cohesion and coordination effects on transition metal surface energies

NASA Astrophysics Data System (ADS)

Ruvireta, Judit; Vega, Lorena; Viñes, Francesc

2017-10-01

Here we explore the accuracy of Stefan equation and broken-bond model semiempirical approaches to obtain surface energies on transition metals. Cohesive factors are accounted for either via the vaporization enthalpies, as proposed in Stefan equation, or via cohesive energies, as employed in the broken-bond model. Coordination effects are considered including the saturation degree, as suggested in Stefan equation, employing Coordination Numbers (CN), or as the ratio of broken bonds, according to the bond-cutting model, considering as well the square root dependency of the bond strength on CN. Further, generalized coordination numbers CN bar are contemplated as well, exploring a total number of 12 semiempirical formulations on the three most densely packed surfaces of 3d, 4d, and 5d Transition Metals (TMs) displaying face-centered cubic (fcc), body-centered cubic (bcc), or hexagonal close-packed (hcp) crystallographic structures. Estimates are compared to available experimental surface energies obtained extrapolated to zero temperature. Results reveal that Stefan formula cohesive and coordination dependencies are only qualitative suited, but unadvised for quantitative discussion, as surface energies are highly overestimated, favoring in addition the stability of under-coordinated surfaces. Broken-bond cohesion and coordination dependencies are a suited basis for quantitative comparison, where square-root dependencies on CN to account for bond weakening are sensibly worse. An analysis using Wulff shaped averaged surface energies suggests the employment of broken-bond model using CN to gain surface energies for TMs, likely applicable to other metals.

Application of Rapid Solidification Techniques to Aluminum Alloys

DTIC Science & Technology

1980-10-01

relatkonship h e 4r eoTs/(T5 TG) (3.7) 32 where e is the surface emissivity, a is the Stefan Boltzmann constant, Ts and TG are the droplet and cooling...their fully implicit form and solved by a Gauss Seidel iteration routine. The results are I I 40I compared with the equivalent Newtonian case and...temperature respectively, Fo is the Fourier number or dimensionless time, Fo = aLt/r2 (5.2) and Ste is the Stefan number, Ste = CL (TM - TG)/AHM (5.3) which

Laser Stimulated Genomic Exchange in Stem Cells. Laser Non-cloning Techniques

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2012-02-01

I propose a novel technique for a pluripotent stem cell generation. Genomic exchange is stimulated by the beat-wave free electron laser, (B-W FEL), frequency matching with the frequencies of the DNAootnotetextJ.D. Watson and F. H. C. Crick, Nature, 171, 737-738 (1953). eigen-oscillations. B-W FEL-1ootnotetextV. Stefan, B.I.Cohen, C. Joshi Science, 243,4890, (Jan 27,1989); Stefan, et al., Bull. APS. 32, No. 9, 1713 (1987); Stefan, APS March-2011, #S1.143; APS- March-2009, #K1.276. scans entire stem cell; B-W FEL-2 probes the chromosomes. The scanning and probing lasers: 300-500nm and 100-300nm, respectively; irradiances: the order-of-10s mW/cm^2 (above the threshold value for a particular gene structure); repetition rate of few-100s Hz. A variety of genetic-matching conditions can be arranged. Genomic glitches, (the cell nucleus transferootnotetextScott Noggle et al. Nature, 478, 70-75 (06 October 2011).), can be hedged by the use of lasers.

Multi-Component Diffusion with Application To Computational Aerothermodynamics

NASA Technical Reports Server (NTRS)

Sutton, Kenneth; Gnoffo, Peter A.

1998-01-01

The accuracy and complexity of solving multicomponent gaseous diffusion using the detailed multicomponent equations, the Stefan-Maxwell equations, and two commonly used approximate equations have been examined in a two part study. Part I examined the equations in a basic study with specified inputs in which the results are applicable for many applications. Part II addressed the application of the equations in the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) computational code for high-speed entries in Earth's atmosphere. The results showed that the presented iterative scheme for solving the Stefan-Maxwell equations is an accurate and effective method as compared with solutions of the detailed equations. In general, good accuracy with the approximate equations cannot be guaranteed for a species or all species in a multi-component mixture. 'Corrected' forms of the approximate equations that ensured the diffusion mass fluxes sum to zero, as required, were more accurate than the uncorrected forms. Good accuracy, as compared with the Stefan- Maxwell results, were obtained with the 'corrected' approximate equations in defining the heating rates for the three Earth entries considered in Part II.

Johanna and Tommy: Two Preschoolers in Sweden with Brittle Bones.

ERIC Educational Resources Information Center

Millde, Kristina; Brodin, Jane

Information is presented for caregivers of Swedish children with osteogenesis imperfecta (brittle bones) and their families. Approximately five children with brittle bones are born in Sweden annually. Two main types of brittle bone disease have been identified: congenita and tarda. Typical symptoms include numerous and unexpected fractures, bluish…

[Jesuits Chemists of Hapsburg Monarchy].

PubMed

Južnič, Stanislav

2016-01-01

The achievements of the Jesuits from the Austrian and Bohemian provinces, who have published books on chemistry are focused. Their links with the area of today's Slovenia are particularly exposed. The guidelines which have enabled prompt victories of the ideas about the structure of matter of Jesuit Ru|er Bokovi are indicated. Inconceivable fast spread of Bošković's adherents in the Hapsburg monarchy is compared with a similar rapid introduction of the kinetic theories of atoms of Slovene Jožef Stefan and Ludwig Boltzmann in the same geographical area. Boltzmann was not only Stefan's best student, but he also married a half Slovenian maid.

Self-Organized Criticality Systems

NASA Astrophysics Data System (ADS)

Aschwanden, M. J.

2013-07-01

Contents: (1) Introduction - Norma B. Crosby --- (2) Theoretical Models of SOC Systems - Markus J. Aschwanden --- (3) SOC and Fractal Geometry - R. T. James McAteer --- (4) Percolation Models of Self-Organized Critical Phenomena - Alexander V. Milovanov --- (5) Criticality and Self-Organization in Branching Processes: Application to Natural Hazards - Álvaro Corral, Francesc Font-Clos --- (6) Power Laws of Recurrence Networks - Yong Zou, Jobst Heitzig, Jürgen Kurths --- (7) SOC computer simolations - Gunnar Pruessner --- (8) SOC Laboratory Experiments - Gunnar Pruessner --- (9) Self-Organizing Complex Earthquakes: Scaling in Data, Models, and Forecasting - Michael K. Sachs et al. --- (10) Wildfires and the Forest-Fire Model - Stefan Hergarten --- (11) SOC in Landslides - Stefan Hergarten --- (12) SOC and Solar Flares - Paul Charbonneau --- (13) SOC Systems in Astrophysics - Markus J. Aschwanden ---

Hawking radiation, the Stefan-Boltzmann law, and unitarization

NASA Astrophysics Data System (ADS)

Giddings, Steven B.

2016-03-01

Where does Hawking radiation originate? A common picture is that it arises from excitations very near or at the horizon, and this viewpoint has supported the ;firewall; argument and arguments for a key role for the UV-dependent entanglement entropy in describing the quantum mechanics of black holes. However, closer investigation of both the total emission rate and the stress tensor of Hawking radiation supports the statement that its source is a near-horizon quantum region, or ;atmosphere,; whose radial extent is set by the horizon radius scale. This is potentially important, since Hawking radiation needs to be modified to restore unitarity, and a natural assumption is that the scales relevant to such modifications are comparable to those governing the Hawking radiation. Moreover, related discussion suggests a resolution to questions regarding extra energy flux in ;nonviolent; scenarios, that does not spoil black hole thermodynamics as governed by the Bekenstein-Hawking entropy.

Senior Research Fellow Wins Major International Science Award | News | NREL

Science.gov Websites

generation (MEG) in semiconductor nanocrystals, also called quantum dots, and recently found efficient MEG in silicon quantum dots. He shares the award with Stefan W. Glunz of the Fraunhofer Institute in Germany

Notes on Experiments.

ERIC Educational Resources Information Center

Physics Education, 1982

1982-01-01

Describes: (1) an apparatus which provides a simple method for measuring Stefan's constant; (2) a simple phase shifting circuit; (3) a radioactive decay computer program (for ZX81); and (4) phase difference between transformer voltages. (Author/JN)

An inverse model for a free-boundary problem with a contact line: Steady case

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

Volkov, Oleg; Protas, Bartosz

2009-07-20

This paper reformulates the two-phase solidification problem (i.e., the Stefan problem) as an inverse problem in which a cost functional is minimized with respect to the position of the interface and subject to PDE constraints. An advantage of this formulation is that it allows for a thermodynamically consistent treatment of the interface conditions in the presence of a contact point involving a third phase. It is argued that such an approach in fact represents a closure model for the original system and some of its key properties are investigated. We describe an efficient iterative solution method for the Stefan problemmore » formulated in this way which uses shape differentiation and adjoint equations to determine the gradient of the cost functional. Performance of the proposed approach is illustrated with sample computations concerning 2D steady solidification phenomena.« less

Heavy Fermion Materials and Quantum Phase Transitions Workshop on Frontiers of the Kondo Effect

DTIC Science & Technology

2016-02-12

Stefan Kirchner (Max Planck) discussed the role of quantum criticality on the superconducting condensation in heavy-fermion superconductors , and...Collin Broholm (Johns Hopkins) discussed magnetic excitations of heavy fermion superconductors . The workshop concluded with a wide-ranging talk by

Ice-­Ocean Thermodynamic Interface and Small-­Scale Issues

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

Turner, Adrian K.

2012-07-02

This presentation discusses: (1) Stefan condition, (2) lower boundary condition of mushy layers, (3) salt flux to ocean from gravity drainage, (4) distribution of salt flux in the ocean, (5) under ice melt ponds and false bottoms, and (6) basal ablation.

Dune recovery after storm erosion on a high-energy beach: Vougot Beach, Brittany (France)

NASA Astrophysics Data System (ADS)

Suanez, Serge; Cariolet, Jean-Marie; Cancouët, Romain; Ardhuin, Fabrice; Delacourt, Christophe

2012-02-01

On 10th March 2008, the high energy storm Johanna hit the French Atlantic coast, generating severe dune erosion on Vougot Beach (Brittany, France). In this paper, the recovery of the dune of Vougot Beach is analysed through a survey of morphological changes and hydrodynamic conditions. Data collection focused on the period immediately following storm Johanna until July 2010, i.e. over two and a half years. Results showed that the dune retreated by a maximum of almost 6 m where storm surge and wave attack were the most energetic. Dune retreat led to the creation of accommodation space for the storage of sediment by widening and elevating space between the pre- and post-storm dune toe, and reducing impacts of the storm surge. Dune recovery started in the month following the storm event and is still ongoing. It is characterised by the construction of "secondary" embryo dunes, which recovered at an average rate of 4-4.5 cm per month, although average monthly volume changes varied from - 1 to 2 m 3.m - 1 . These embryo dunes accreted due to a large aeolian sand supply from the upper tidal beach to the existing foredune. These dune-construction processes were facilitated by growth of vegetation on low-profile embryo dunes promoting backshore accretion. After more than two years of survey, the sediment budget of the beach/dune system showed that more than 10,000 m 3 has been lost by the upper tidal beach. We suggest that seaward return currents generated during the storm of 10th March 2008 are responsible for offshore sediment transport. Reconstitution of the equilibrium beach profile following the storm event may therefore have generated cross-shore sediment redistribution inducing net erosion in the tidal zone.

Authorship Correction: Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling.

PubMed

Rao, Amrita; Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

2018-01-15

[This corrects the article DOI: 10.2196/publichealth.8116.]. ©Amrita Rao, Shauna Stahlman, James Hargreaves, Sharon Weir, Jessie Edwards, Brian Rice, Duncan Kochelani, Mpumelelo Mavimbela, Stefan Baral. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 15.01.2018.

Language Crossings: Negotiating the Self in a Multicultural World. Language and Literacy Series.

ERIC Educational Resources Information Center

Ogulnick, Karen, Ed.

This book includes 25 papers in 5 parts. Part 1, "Dislocations," includes (1) "Puzzle" (Myrna Nieves); (2) "No Language To Die In" (Greta Hofmann Nemiroff); (3) "Here's Your Change 'N Enjoy the Show" (Verena Stefan); (4) "The Vagabond Years" (Elizabeth Dykman); (5) "From Bayamon to…

The Cybersecurity Challenge in Acquisition

DTIC Science & Technology

2016-04-30

problems. Scarier yet, another group took control of a car’s computers through a cellular telephone and Bluetooth connections and could access...did more extensive work, hacking their way into a 2009 midsize car through its cellular, Bluetooth , and other wireless connections. Stefan Savage, a

Aporias, Politics of Ontology, Ethics, and "We"?

ERIC Educational Resources Information Center

Bengtsson, Stefan Lars

2016-01-01

The different responses, interpretations, and consequent critiques of Stefan Lars Bengtsson's "Hegemony and the Politics of Policy Making for Education for Sustainable Development" highlight how the various critical outlooks are framed by, seemingly, incommensurable positions, or figures of reasoning, that inform their thinking.…

A World Where All Worlds Cohabit

ERIC Educational Resources Information Center

Teamey, Kelly; Mandel, Udi

2016-01-01

In response to Stefan Bengtsson's search for alternatives to Education for Sustainable Development practices outside the mainstream of the state and its policy formulations, this response outlines how our journey, experiences, and approaches reflect a de-professionalizing encounter with autonomous places of learning emerging from indigenous…

High-Performing Primary Care Teams: Creating The Air Force Medical Home Advantage

DTIC Science & Technology

2015-02-17

Geneau, Claudio Del Grande, Jean-Louis Denis, Eveline Hudon, Jeannie Haggerty, Lucie Bonin, Rejean Duplain, Johanne Goudrea and William Hogg . "Providing...Eisen, Stefan. Practical Guide to Negotiating in the Military. 2nd. Montgomery, AL: USAF Negotiation Center of Excellence, 2013. Green, Charles B. "The

Losing Traction and the Art of Slip-Sliding Away: Or, Getting over Education for Sustainable Development

ERIC Educational Resources Information Center

Jickling, Bob

2016-01-01

This response problematizes Stefan Bengtsson's (2016) defense of education for sustainable development. He argues that sustainable development and education for sustainable development are not globalizing and hegemonic discourses, as some have claimed, and uses case-study analysis of Vietnamese policy documents to support his claims. He observes…

Bayesian Authentication: Quantifying Security of the Hancke-Kuhn Protocol

DTIC Science & Technology

2010-01-01

Conference on Advances in Cryptology, pages 169–177, London, UK, 1991. Springer-Verlag. [6] Stefan Brands and David Chaum . Distance-bounding protocols. In...Lecture Notes in Computer Science, pages 371–388. Springer, 2004. [30] Patrick Schaller, Benedikt Schmidt, David Basin, and Srdjan Capkun. Modeling and

77 FR 5308 - Quarterly Publication of Individuals, Who Have Chosen To Expatriate, as Required by Section 6039G

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-02

............ GRIMM KATJA GROENEN FRANK GRONER ELIYAHU DAVID GRONING MARC E GUNNARSSON GUNNAR-THOR....... BJORNSSON... ARTHUR HANSSON KARL STEFAN HARPER-VANDAMME BRENDA CHRISTIAN HARVEY BRUCE E HARVEY RALPH DIETER HASLER... HILLIARD ELAINE GARDINER WELCH HO LESLIE SAI KIT HOCHHEIMER SUZANNE TRUDY HOLUB BARBARA RENE HRYNIUK LYNN E...

Strengthening US DoD Cyber Security with the Vulnerability Market

DTIC Science & Technology

2013-06-01

is with their constant assurance that I find strength. I would also like to acknowledge my cyber- colleagues, Maj Ronald “Rusty” Clark, Maj Vanessa ...Michel J.G. van Eeten, Delft University of Technology; Michael Levi, Cardiff University; Tyler Moore, Southern Methodist University; and Stefan Savage

Kinetics Modeling of Hypergolic Propellants

DTIC Science & Technology

2013-07-01

comprehensive preconditioning and employs the line Gauss Seidel algorithm for the solution of the linear system. A multi-block unstructured mesh is...Explosives, Pyrotechnics, 33(3):209–212, 2008. 24Wei-Guang Liu, Shiqing Wang, Siddharth Dasgupta, Stefan T Thynell, William A Goddard III, Sergey Zybin

Translations on Eastern Europe Political, Sociological, and Military Affairs No. 1572.

DTIC Science & Technology

1978-08-01

they are subordinated. Stefan Leskovjansky, a member of management of the construction group at the Unified Agricultural Cooperative Klatov, gained...German relations. The first step was not easy for Honecker. Only a short time ago the SED chief had asked Karl Seidel , department head in the GDR

Pulsed electric field processing for fruit and vegetables

USDA-ARS?s Scientific Manuscript database

This month’s column reviews the theory and current applications of pulsed electric field (PEF) processing for fruits and vegetables to improve their safety and quality. This month’s column coauthor, Stefan Toepfl, is advanced research manager at the German Institute of Food Technologies and professo...

Teaching as a Reflective Practice: The German Didaktik Tradition. Studies in Curriculum Theory Series.

ERIC Educational Resources Information Center

Westbury, Ian, Ed.; Hopmann, Stefan, Ed.; Riquarts, Kurt, Ed.

This collection of papers presents essays by German scholars and practitioners writing from within the German Didaktik tradition and interpretive essays by U.S. scholars. After an introduction, "Starting a Dialogue: A Beginning Conversation between Didaktik and the Curriculum Traditions" (Stefan Hopmann and Kurt Riquarts), there are 18…

Ruling Relationships in Sustainable Development and Education for Sustainable Development

ERIC Educational Resources Information Center

Berryman, Tom; Sauvé, Lucie

2016-01-01

It is from historical perspectives on more than 40 years of environment related education theories, practices, and policies that we revisit what might otherwise become a tired conversation about environmental education and sustainable development. Our contemporary critical analysis of Stefan Bengtsson's research about policy making leads us to…

Protein diffusiophoresis and salt osmotic diffusion in aqueous solutions.

PubMed

Annunziata, Onofrio; Buzatu, Daniela; Albright, John G

2012-10-25

Diffusion of a solute can be induced by the concentration gradient of another solute in solution. This transport mechanism is known as cross-diffusion. We have investigated cross-diffusion in a ternary protein-salt-water system. Specifically, we measured the two cross-diffusion coefficients for the lysozyme-NaCl-water system at 25 °C and pH 4.5 as a function of protein and salt concentrations by Rayleigh interferometry. One cross-diffusion coefficient characterizes salt osmotic diffusion induced by a protein concentration gradient, and is related to protein-salt thermodynamic interactions as described by the theories of Donnan membrane equilibrium and protein preferential hydration. The other cross-diffusion coefficient characterizes protein diffusiophoresis induced by a salt concentration gradient, and is described as the difference between a preferential-interaction coefficient and a transport parameter. We first relate our experimental results to the protein net charge and the thermodynamic excess of water near the protein surface. We then extract the Stefan-Maxwell diffusion coefficient describing protein-salt interactions in water. We find that the value of this coefficient is negative, contrary to the friction interpretation of Stefan-Maxwell equations. This result is explained by considering protein hydration. Finally, protein diffusiophoresis is quantitatively examined by considering electrophoretic and hydration effects on protein migration and utilized to accurately estimate lysozyme electrophoretic mobility. To our knowledge, this is the first time that protein diffusiophoresis has been experimentally characterized and a protein-salt Stefan-Maxwell diffusion coefficient reported. This work represents a significant contribution for understanding and modeling the effect of concentration gradients in protein-salt aqueous systems relevant to diffusion-based mass-transfer technologies and transport in living systems.

"Neverwinter Nights" in Alberta: Conceptions of Narrativity through Fantasy Role-Playing Games in a Graduate Classroom

ERIC Educational Resources Information Center

Gouglas, Sean; Sinclair, Stefan; Ellefson, Olaf; Sharplin, Scott

2006-01-01

Most humanities courses rarely require students to create the kinds of work they are studying. Sean Gouglas, Stefan Sinclair, Olaf Ellefson, and Scott Sharplin outline the value of this rare experience by describing an assignment in their graduate humanities computing course in which students examined hypermedia narratives by authoring a…

Modelling of active layer thickness evolution on James Ross Island in 2006-2015

NASA Astrophysics Data System (ADS)

Hrbáček, Filip; Uxa, Tomáš

2017-04-01

Antarctic Peninsula region has been considered as one of the most rapidly warming areas on the Earth. However, the recent studies (Turner et al., 2016; Oliva et al., 2017) showed that significant air temperature cooling began around 2000 and has continued until present days. The climate cooling led to reduction of active layer thickness in several parts of Antarctic Peninsula region during decade 2006-2015, but the information about spatiotemporal variability of active layer thickness across the region remains largely incoherent due to lack of active layer temperature data from deeper profiles. Valuable insights into active layer thickness evolution in Antarctic Peninsula region can be, however, provided by thermal modelling techniques. These have been widely used to study the active layer dynamics in different regions of Arctic since 1990s. By contrast, they have been employed much less in Antarctica. In this study, we present our first results from two equilibrium models, the Stefan and Kudryavtsev equations, that were applied to calculate the annual active layer thickness based on ground temperature data from depth of 5 cm on one site on James Ross Island, Eastern Antarctic Peninsula, in period 2006/07 to 2014/15. Study site (Abernethy Flats) is located in the central part of the major ice-free area of James Ross Island called Ulu Peninsula. Monitoring of air temperature 2 m above ground surface and ground temperature in 50 cm profile began on January 2006. The profile was extended under the permafrost table down to 75 cm in February 2012, which allowed precise determination of active layer thickness, defined as a depth of 0°C isotherm, in period 2012 to 2015. The active layer thickness in the entire observation period was reconstructed using the Stefan and Kudryavtsev models, which were driven by ground temperature data from depth of 5 cm and physical parameters of the ground obtained by laboratory analyses (moisture content and bulk density) and calculations

Stefan Jellinek (1871-1968): The only professor of electro-pathology.

PubMed

Jellinek, E H

2016-08-01

The exploding use of electricity in homes and industry in the second half of the 19th century was accompanied by many injuries and fatalities from electric currents. Their study by my father was the serendipitous outcome of his early work on possible blood pressure changes from electric currents in a career that started in internal medicine. It became his limited field of electro-pathology which embraced first aid, the care of the injured, histopathology and accident prevention. He was an enthusiastic teacher and collector of specimens, from tree trunks struck by lightning down to the microscopy of accidental and experimental electric lesions. © The Author(s) 2016.

Assessment: Monitoring & Evaluation in a Stabilisation Context

DTIC Science & Technology

2010-09-15

http://www.oecd.org/dataoecd/23/27/35281194.pdf b. SIDA (2004), The Logical Framework Approach. A summary of the theory behind the LFA method...en_21571361_34047972_39774574 _1_1_1_1,00.pdf 3. SIDA (2004), Stefan Molund and Göran Schill, Looking Back, Moving Forward, Sida Evaluation Manual. Available at

Democracy and Education in the Twenty-First Century: Deweyan Pragmatism and the Question of Racism

ERIC Educational Resources Information Center

Neubert, Stefan

2010-01-01

Why is John Dewey still such an important philosopher today? Writing from the perspective of the Cologne Program of Interactive Constructivism, Stefan Neubert tries in what follows to give one possible answer to this question. Neubert notes that Cologne constructivism considers Dewey in many respects as one of the most important predecessors of…

On Blackbody Radiation.

ERIC Educational Resources Information Center

Jain, Pushpendra K.

1991-01-01

The interrelationship between the various forms of the Planck radiation equation is discussed. A differential equation that gives intensity or energy density of radiation per unit wavelength or per unit frequency is emphasized. The Stefan-Boltzmann Law and the change in the glow of a hot body with temperature are also discussed. (KR)

Adding Albedo and Atmospheres

ERIC Educational Resources Information Center

LoPresto, Michael C.

2013-01-01

In a previous article in this journal, we reported on a laboratory activity in which students used a derivation from the Stefan-Boltzmann law to calculate planetary temperatures and compare them to measured values from various (mostly online) sources. The calculated temperatures matched observed values very well with the exceptions of Venus and…

Finding Truth in "Lies": Nietzsche's Perspectivism and Its Relation to Education

ERIC Educational Resources Information Center

Jonas, Mark E.; Nakazawa, Yoshiaki M.

2008-01-01

In his 2001 article "Teaching to Lie and Obey: Nietzsche on Education", Stefan Ramaekers defends Nietzsche's concept of perspectivism against the charge that it is relativistic. He argues that perspectivism is not relativistic because it denies the dichotomy between the "true" world and the "seeming" world, a dichotomy central to claims to…

Graphic Novels in the Classroom

ERIC Educational Resources Information Center

Martin, Adam

2009-01-01

Today many authors and artists adapt works of classic literature into a medium more "user friendly" to the increasingly visual student population. Stefan Petrucha and Kody Chamberlain's version of "Beowulf" is one example. The graphic novel captures the entire epic in arresting images and contrasts the darkness of the setting and characters with…

Probing Planck's Law at Home

ERIC Educational Resources Information Center

Bonnet, I.; Gabelli, J.

2010-01-01

We report on the physics around an incandescent lamp. Using a consumer-grade digital camera, we combine electrical and optical measurements to explore Planck's law of black-body radiation. This simple teaching experiment is successfully used to measure both Stefan's and Planck's constants. Our measurements lead to a strikingly accurate value for…

Time to Reframe Politics and Practices in Correctional Education

ERIC Educational Resources Information Center

LoBuglio, Stefan

2001-01-01

In this chapter, Stefan LoBuglio discusses the politics and practices of educational programs for adults in correctional facilities. To begin, LoBuglio provides an overview of the field of corrections, including various types of facilities and correctional programs, as well as demographic and educational data on the U.S. incarcerated population…

Effect of soil property uncertainties on permafrost thaw projections: A calibration-constrained analysis

DOE PAGES

Harp, Dylan R.; Atchley, Adam L.; Painter, Scott L.; ...

2016-02-11

Here, the effect of soil property uncertainties on permafrost thaw projections are studied using a three-phase subsurface thermal hydrology model and calibration-constrained uncertainty analysis. The Null-Space Monte Carlo method is used to identify soil hydrothermal parameter combinations that are consistent with borehole temperature measurements at the study site, the Barrow Environmental Observatory. Each parameter combination is then used in a forward projection of permafrost conditions for the 21more » $$^{st}$$ century (from calendar year 2006 to 2100) using atmospheric forcings from the Community Earth System Model (CESM) in the Representative Concentration Pathway (RCP) 8.5 greenhouse gas concentration trajectory. A 100-year projection allows for the evaluation of intra-annual uncertainty due to soil properties and the inter-annual variability due to year to year differences in CESM climate forcings. After calibrating to borehole temperature data at this well-characterized site, soil property uncertainties are still significant and result in significant intra-annual uncertainties in projected active layer thickness and annual thaw depth-duration even with a specified future climate. Intra-annual uncertainties in projected soil moisture content and Stefan number are small. A volume and time integrated Stefan number decreases significantly in the future climate, indicating that latent heat of phase change becomes more important than heat conduction in future climates. Out of 10 soil parameters, ALT, annual thaw depth-duration, and Stefan number are highly dependent on mineral soil porosity, while annual mean liquid saturation of the active layer is highly dependent on the mineral soil residual saturation and moderately dependent on peat residual saturation. By comparing the ensemble statistics to the spread of projected permafrost metrics using different climate models, we show that the effect of calibration-constrained uncertainty in soil properties

Effect of soil property uncertainties on permafrost thaw projections: A calibration-constrained analysis

DOE PAGES

Harp, D. R.; Atchley, A. L.; Painter, S. L.; ...

2015-06-29

The effect of soil property uncertainties on permafrost thaw projections are studied using a three-phase subsurface thermal hydrology model and calibration-constrained uncertainty analysis. The Null-Space Monte Carlo method is used to identify soil hydrothermal parameter combinations that are consistent with borehole temperature measurements at the study site, the Barrow Environmental Observatory. Each parameter combination is then used in a forward projection of permafrost conditions for the 21st century (from calendar year 2006 to 2100) using atmospheric forcings from the Community Earth System Model (CESM) in the Representative Concentration Pathway (RCP) 8.5 greenhouse gas concentration trajectory. A 100-year projection allows formore » the evaluation of intra-annual uncertainty due to soil properties and the inter-annual variability due to year to year differences in CESM climate forcings. After calibrating to borehole temperature data at this well-characterized site, soil property uncertainties are still significant and result in significant intra-annual uncertainties in projected active layer thickness and annual thaw depth-duration even with a specified future climate. Intra-annual uncertainties in projected soil moisture content and Stefan number are small. A volume and time integrated Stefan number decreases significantly in the future climate, indicating that latent heat of phase change becomes more important than heat conduction in future climates. Out of 10 soil parameters, ALT, annual thaw depth-duration, and Stefan number are highly dependent on mineral soil porosity, while annual mean liquid saturation of the active layer is highly dependent on the mineral soil residual saturation and moderately dependent on peat residual saturation. As a result, by comparing the ensemble statistics to the spread of projected permafrost metrics using different climate models, we show that the effect of calibration-constrained uncertainty in soil properties

Effect of soil property uncertainties on permafrost thaw projections: a calibration-constrained analysis

NASA Astrophysics Data System (ADS)

Harp, D. R.; Atchley, A. L.; Painter, S. L.; Coon, E. T.; Wilson, C. J.; Romanovsky, V. E.; Rowland, J. C.

2015-06-01

The effect of soil property uncertainties on permafrost thaw projections are studied using a three-phase subsurface thermal hydrology model and calibration-constrained uncertainty analysis. The Null-Space Monte Carlo method is used to identify soil hydrothermal parameter combinations that are consistent with borehole temperature measurements at the study site, the Barrow Environmental Observatory. Each parameter combination is then used in a forward projection of permafrost conditions for the 21st century (from calendar year 2006 to 2100) using atmospheric forcings from the Community Earth System Model (CESM) in the Representative Concentration Pathway (RCP) 8.5 greenhouse gas concentration trajectory. A 100-year projection allows for the evaluation of intra-annual uncertainty due to soil properties and the inter-annual variability due to year to year differences in CESM climate forcings. After calibrating to borehole temperature data at this well-characterized site, soil property uncertainties are still significant and result in significant intra-annual uncertainties in projected active layer thickness and annual thaw depth-duration even with a specified future climate. Intra-annual uncertainties in projected soil moisture content and Stefan number are small. A volume and time integrated Stefan number decreases significantly in the future climate, indicating that latent heat of phase change becomes more important than heat conduction in future climates. Out of 10 soil parameters, ALT, annual thaw depth-duration, and Stefan number are highly dependent on mineral soil porosity, while annual mean liquid saturation of the active layer is highly dependent on the mineral soil residual saturation and moderately dependent on peat residual saturation. By comparing the ensemble statistics to the spread of projected permafrost metrics using different climate models, we show that the effect of calibration-constrained uncertainty in soil properties, although significant, is

Basal melting driven by turbulent thermal convection

NASA Astrophysics Data System (ADS)

Rabbanipour Esfahani, Babak; Hirata, Silvia C.; Berti, Stefano; Calzavarini, Enrico

2018-05-01

Melting and, conversely, solidification processes in the presence of convection are key to many geophysical problems. An essential question related to these phenomena concerns the estimation of the (time-evolving) melting rate, which is tightly connected to the turbulent convective dynamics in the bulk of the melt fluid and the heat transfer at the liquid-solid interface. In this work, we consider a convective-melting model, constructed as a generalization of the Rayleigh-Bénard system, accounting for the basal melting of a solid. As the change of phase proceeds, a fluid layer grows at the heated bottom of the system and eventually reaches a turbulent convection state. By means of extensive lattice-Boltzmann numerical simulations employing an enthalpy formulation of the governing equations, we explore the model dynamics in two- and three-dimensional configurations. The focus of the analysis is on the scaling of global quantities like the heat flux and the kinetic energy with the Rayleigh number, as well as on the interface morphology and the effects of space dimensionality. Independently of dimensionality, we find that the convective-melting system behavior shares strong resemblances with that of the Rayleigh-Bénard one, and that the heat flux is only weakly enhanced with respect to that case. Such similarities are understood, at least to some extent, considering the resulting slow motion of the melting front (with respect to the turbulent fluid velocity fluctuations) and its generally little roughness (compared to the height of the fluid layer). Varying the Stefan number, accounting for the thermodynamical properties of the material, also seems to have only a mild effect, which implies the possibility of extrapolating results in numerically delicate low-Stefan setups from more convenient high-Stefan ones. Finally, we discuss the implications of our findings for the geophysically relevant problem of modeling Arctic ice melt ponds.

Properties of Fluorinated Graphene Films

DTIC Science & Technology

2010-04-01

Properties of Fluorinated Graphene Films Jeremy T. Robinson,* James S. Burgess, Chad E. Junkermeier, Stefan C. Badescu, Thomas L. Reinecke, F. Keith...G. S.; Graham, A. P.; Kreupl, F.; Seidel , R.; Hoenlein, W. Chem. Phys. Lett. 2004, 399 (1-3), 280– 283. (19) Li, X.; Cai, W.; An, J.; Kim, S.; Nah, J

Homosexuality, Manliness and the United States

DTIC Science & Technology

2010-03-25

LIMITATION OF ABSTRACT 18 . NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON Stefan A. Banach, U.S. Army a. REPORT b. ABSTRACT c. THIS PAGE... 18 Australia...cause is masculine in its origin and subjugates women for fear that their “ erotic power threatens to infect him with feminine softness.” It is

Homosexuality, Manliness, and the United States Army

DTIC Science & Technology

2010-05-01

LIMITATION OF ABSTRACT 18 . NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON Stefan A. Banach, U.S. Army a. REPORT b. ABSTRACT c. THIS PAGE... 18 Australia...cause is masculine in its origin and subjugates women for fear that their “ erotic power threatens to infect him with feminine softness.” It is

Entropy density of an adiabatic relativistic Bose-Einstein condensate star

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

Khaidir, Ahmad Firdaus; Kassim, Hasan Abu; Yusof, Norhasliza

Inspired by recent works, we investigate how the thermodynamics parameters (entropy, temperature, number density, energy density, etc) of Bose-Einstein Condensate star scale with the structure of the star. Below the critical temperature in which the condensation starts to occur, we study how the entropy behaves with varying temperature till it reaches its own stability against gravitational collapse and singularity. Compared to photon gases (pressure is described by radiation) where the chemical potential, μ is zero, entropy of photon gases obeys the Stefan-Boltzmann Law for a small values of T while forming a spiral structure for a large values of Tmore » due to general relativity. The entropy density of Bose-Einstein Condensate is obtained following the similar sequence but limited under critical temperature condition. We adopt the scalar field equation of state in Thomas-Fermi limit to study the characteristics of relativistic Bose-Einstein condensate under varying temperature and entropy. Finally, we obtain the entropy density proportional to (σT{sup 3}-3T) which obeys the Stefan-Boltzmann Law in ultra-relativistic condition.« less

Optimal Control of Thermo--Fluid Phenomena in Variable Domains

NASA Astrophysics Data System (ADS)

Volkov, Oleg; Protas, Bartosz

2008-11-01

This presentation concerns our continued research on adjoint--based optimization of viscous incompressible flows (the Navier--Stokes problem) coupled with heat conduction involving change of phase (the Stefan problem), and occurring in domains with variable boundaries. This problem is motivated by optimization of advanced welding techniques used in automotive manufacturing, where the goal is to determine an optimal heat input, so as to obtain a desired shape of the weld pool surface upon solidification. We argue that computation of sensitivities (gradients) in such free--boundary problems requires the use of the shape--differential calculus as a key ingredient. We also show that, with such tools available, the computational solution of the direct and inverse (optimization) problems can in fact be achieved in a similar manner and in a comparable computational time. Our presentation will address certain mathematical and computational aspects of the method. As an illustration we will consider the two--phase Stefan problem with contact point singularities where our approach allows us to obtain a thermodynamically consistent solution.

Featured Image: Experimental Simulation of Melting Meteoroids

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-03-01

Ever wonder what experimental astronomy looks like? Some days, it looks like this piece of rock in a wind tunnel (click for a betterlook!). In this photo, a piece of agrillite (a terrestrial rock) is exposed to conditions in a plasma wind tunnel as a team of scientists led by Stefan Loehle (Stuttgart University) simulate what happens to a meteoroid as it hurtles through Earths atmosphere. With these experiments, the scientists hope to better understand meteoroid ablation the process by which meteoroids are heated, melt, and evaporateas they pass through our atmosphere so that we can learn more from the meteorite fragments that make it to the ground. In the scientists experiment, the rock samples were exposed to plasma flow until they disintegrated, and this process was simultaneously studied via photography, video, high-speed imaging, thermography, and Echelle emission spectroscopy. To find out what the team learned from these experiments, you can check out the original article below.CitationStefan Loehle et al 2017 ApJ 837 112. doi:10.3847/1538-4357/aa5cb5

Droplet size effects on film drainage between droplet and substrate.

PubMed

Steinhaus, Benjamin; Spicer, Patrick T; Shen, Amy Q

2006-06-06

When a droplet approaches a solid surface, the thin liquid film between the droplet and the surface drains until an instability forms and then ruptures. In this study, we utilize microfluidics to investigate the effects of film thickness on the time to film rupture for water droplets in a flowing continuous phase of silicone oil deposited on solid poly(dimethylsiloxane) (PDMS) surfaces. The water droplets ranged in size from millimeters to micrometers, resulting in estimated values of the film thickness at rupture ranging from 600 nm down to 6 nm. The Stefan-Reynolds equation is used to model film drainage beneath both millimeter- and micrometer-scale droplets. For millimeter-scale droplets, the experimental and analytical film rupture times agree well, whereas large differences are observed for micrometer-scale droplets. We speculate that the differences in the micrometer-scale data result from the increases in the local thin film viscosity due to confinement-induced molecular structure changes in the silicone oil. A modified Stefan-Reynolds equation is used to account for the increased thin film viscosity of the micrometer-scale droplet drainage case.

PEG 400-Based Phase Change Materials Nano-Enhanced with Functionalized Graphene Nanoplatelets.

PubMed

Marcos, Marco A; Cabaleiro, David; Guimarey, María J G; Comuñas, María J P; Fedele, Laura; Fernández, Josefa; Lugo, Luis

2017-12-29

This study presents new Nano-enhanced Phase Change Materials, NePCMs, formulated as dispersions of functionalized graphene nanoplatelets in a poly(ethylene glycol) with a mass-average molecular mass of 400 g·mol -1 for possible use in Thermal Energy Storage. Morphology, functionalization, purity, molecular mass and thermal stability of the graphene nanomaterial and/or the poly(ethylene glycol) were characterized. Design parameters of NePCMs were defined on the basis of a temporal stability study of nanoplatelet dispersions using dynamic light scattering. Influence of graphene loading on solid-liquid phase change transition temperature, latent heat of fusion, isobaric heat capacity, thermal conductivity, density, isobaric thermal expansivity, thermal diffusivity and dynamic viscosity were also investigated for designed dispersions. Graphene nanoplatelet loading leads to thermal conductivity enhancements up to 23% while the crystallization temperature reduces up to in 4 K. Finally, the heat storage capacities of base fluid and new designed NePCMs were examined by means of the thermophysical properties through Stefan and Rayleigh numbers. Functionalized graphene nanoplatelets leads to a slight increase in the Stefan number.

PEG 400-Based Phase Change Materials Nano-Enhanced with Functionalized Graphene Nanoplatelets

PubMed Central

Marcos, Marco A.; Guimarey, María J. G.; Comuñas, María J. P.

2017-01-01

This study presents new Nano-enhanced Phase Change Materials, NePCMs, formulated as dispersions of functionalized graphene nanoplatelets in a poly(ethylene glycol) with a mass-average molecular mass of 400 g·mol−1 for possible use in Thermal Energy Storage. Morphology, functionalization, purity, molecular mass and thermal stability of the graphene nanomaterial and/or the poly(ethylene glycol) were characterized. Design parameters of NePCMs were defined on the basis of a temporal stability study of nanoplatelet dispersions using dynamic light scattering. Influence of graphene loading on solid-liquid phase change transition temperature, latent heat of fusion, isobaric heat capacity, thermal conductivity, density, isobaric thermal expansivity, thermal diffusivity and dynamic viscosity were also investigated for designed dispersions. Graphene nanoplatelet loading leads to thermal conductivity enhancements up to 23% while the crystallization temperature reduces up to in 4 K. Finally, the heat storage capacities of base fluid and new designed NePCMs were examined by means of the thermophysical properties through Stefan and Rayleigh numbers. Functionalized graphene nanoplatelets leads to a slight increase in the Stefan number. PMID:29286324

Ecological occurrence of Gluconacetobacter diazotrophicus and nitrogen-fixing Acetobacteraceae members: their possible role in plant growth promotion.

PubMed

Saravanan, V S; Madhaiyan, M; Osborne, Jabez; Thangaraju, M; Sa, T M

2008-01-01

Gluconacetobacter diazotrophicus has a long-standing history of bacterial-plant interrelationship as a symbiotic endophyte capable of fixing atmospheric nitrogen. In low nitrogen fertilized sugarcane fields it plays a significant role and its occurrence was realised in most of the sugarcane growing countries. In this mini review, the association of G. diazotrophicus with sugarcane, other crop plants and with various hosts is discussed. The factors affecting survival in the rhizosphere and the putative soil mode of transmission are emphasized. In addition, other N(2)-fixing Acetobacteraceae members, including Gluconacetobacter azotocaptans, Gluconacetobacter johannae and Swaminathania salitolerans, occurring in coffee, corn and rice plants are also covered. Lastly, the plant-growth-promoting traits identified in this group of bacteria, including N(2) fixation, phytohormone synthesis, P and Zn solubilization and biocontrol, are analysed.

Reconstructing Deweyan Pragmatism: A Review Essay

ERIC Educational Resources Information Center

Neubert, Stefan

2009-01-01

In this essay Stefan Neubert argues that John Dewey was a philosopher of reconstruction and that the best use we can make of him today is to reconstruct his work in and for our own contexts. Neubert distinguishes three necessary and equally important components of the overall project of reconstructing Deweyan pragmatism: first, to make strong and…

The drop heard round the world

NASA Astrophysics Data System (ADS)

Bergin, Shane D.; Hutzler, Stefan; Weaire

2014-05-01

When physicists at Trinity College Dublin began looking after an antique funnel full of pitch, they had no idea their humble experiment would spawn one of 2013's most “viral” news stories. Shane D Bergin, Stefan Hutzler and Denis Weaire reflect on the value of “slow science” to a hyper-connected, social-media world.

Directory of Czechoslovak Officials; a Reference Aid

DTIC Science & Technology

1988-07-14

Jaroslav; KSS Barilla , Jan KSS Horvath, Stefan: A’SS Bartak, Stel’an KSS Horvathova, Marta: KSC Barton, Jaroslav Hricko, Peter: KSS Benyo, Matus: KSS...61 Bilek. Jin 78 Banarova. Eva is Bilek, /denck 4’) Barak, Ladislav 71 Biro~s, Branislav 10.40.41, Barilla , Jan .11 Bisko. fir,, Harlot’s, Paulina 6

2016 Emerging Technology Domains Risk Survey

DTIC Science & Technology

2016-04-05

2016 Emerging Technology Domains Risk Survey Christopher King Dan Klinedinst Todd Lewellen Garret Wassermann April 2016 TECHNICAL REPORT...Unlimited [Checkoway 2011] Checkoway, Stephen; McCoy, Damon; Kantor, Brian; Anderson, Danny; Shacham, Hovav; Savage, Stefan. Comprehensive Experimental ...Koscher 2010] Koscher, Karl et al. “ Experimental Security Analysis of a Modern Automobile,” 447-462. IEEE Symposium on Security and Privacy

Blackbody Radiation from an Incandescent Lamp

ERIC Educational Resources Information Center

Ribeiro, C. I.

2014-01-01

In this article we propose an activity aimed at introductory students to help them understand the Stefan-Boltzmann and Wien's displacement laws. It only requires simple materials that are available at any school: an incandescent lamp, a variable dc energy supply, and a computer to run an interactive simulation of the blackbody spectrum.…

Figures of Disengagement: Charles Taylor, Scientific Parenting, and the Paradox of Late Modernity

ERIC Educational Resources Information Center

Van den Berge, Luc; Ramaekers, Stefan

2014-01-01

In this essay Luc Van den Berge and Stefan Ramaekers take the idea(l) of "scientific parenting" as an example of ambiguities that are typical of our late-modern condition. On the one hand, parenting seems like a natural thing to do, which makes "scientific parenting" sound like an oxymoron; on the other hand, a disengaged…

Effects of Heat Acclimation on Heat-Exercise Tolerance in Untrained and Endurance-Trained Men Wearing NBC Protective Clothing

DTIC Science & Technology

1993-08-01

2-1 + 273.15]’.(A.A"•1 ) (Eq. 5) h. = 23.4.v,.ŗ" (Eq. 6) in which a is the Stefan -Boltzmann constant (20.4-10-8 UNCLASSIFIED 8 UNCLASSIFIED kJ-m-’-h...Vallerand AL, Limmer R, Schmegner IF (1989) Computer acquisition and analysis of skin temperature and heat flow data from heat flux transducers. Computer

Modeling and 3D-simulation of hydrogen production via methanol steam reforming in copper-coated channels of a mini reformer

NASA Astrophysics Data System (ADS)

Sari, Ataallah; Sabziani, Javad

2017-06-01

Modeling and CFD simulation of a three-dimensional microreactor includes thirteen structured parallel channels is performed to study the hydrogen production via methanol steam reforming reaction over a Cu/ZnO/Al2O3 catalyst. The well-known Langmuir-Hinshelwood macro kinetic rate expressions reported by Peppley and coworkers [49] are considered to model the methanol steam reforming reactions. The effects of inlet steam to methanol ratio, pre-heat temperature, channels geometry and size, and the level of external heat flux on the hydrogen quality and quantity (i.e., hydrogen flow rate and CO concentration) are investigated. Moreover, the possibility of reducing the CO concentration by passing the reactor effluent through a water gas shift channel placed in series with the methanol reformer is studied. Afterwards, the simulation results are compared with the experimental data reported in the literature considering two different approaches of mixture-averaged and Maxwell-Stefan formulations to evaluate the diffusive flux of mass. The results indicate that the predictions of the Maxwell-Stefan model is in better agreement with experimental data than mixture-averaged one, especially at the lower feed flow rates.

Evidence of high-elevation amplification versus Arctic amplification

NASA Astrophysics Data System (ADS)

Wang, Qixiang; Fan, Xiaohui; Wang, Mengben

2016-01-01

Elevation-dependent warming in high-elevation regions and Arctic amplification are of tremendous interest to many scientists who are engaged in studies in climate change. Here, using annual mean temperatures from 2781 global stations for the 1961-2010 period, we find that the warming for the world’s high-elevation stations (>500 m above sea level) is clearly stronger than their low-elevation counterparts; and the high-elevation amplification consists of not only an altitudinal amplification but also a latitudinal amplification. The warming for the high-elevation stations is linearly proportional to the temperature lapse rates along altitudinal and latitudinal gradients, as a result of the functional shape of Stefan-Boltzmann law in both vertical and latitudinal directions. In contrast, neither altitudinal amplification nor latitudinal amplification is found within the Arctic region despite its greater warming than lower latitudes. Further analysis shows that the Arctic amplification is an integrated part of the latitudinal amplification trend for the low-elevation stations (≤500 m above sea level) across the entire low- to high-latitude Northern Hemisphere, also a result of the mathematical shape of Stefan-Boltzmann law but only in latitudinal direction.

Self-diffusivity and interdiffusivity of molten aluminum-copper alloys under pressure, derived from molecular dynamics.

PubMed

Rudd, Robert E; Cabot, William H; Caspersen, Kyle J; Greenough, Jeffrey A; Richards, David F; Streitz, Frederick H; Miller, Paul L

2012-03-01

We use molecular dynamics (MD) to simulate diffusion in molten aluminum-copper (AlCu) alloys. The self-diffusivities and Maxwell-Stefan diffusivities are calculated for AlCu mixtures using the Green-Kubo formulas at temperatures from 1000 to 4000 K and pressures from 0 to 25 GPa, along with additional points at higher temperatures and pressures. The diffusivities are corrected for finite-size effects. The Maxwell-Stefan diffusivity is compared to the diffusivity calculated from the self-diffusivities using a generalization of the Darken equation. We find that the effects of cross-correlation are small. Using the calculated self-diffusivities, we have assessed whether dilute hard-sphere and dilute Lennard-Jones models apply to the molten mixture. Neither of the two dilute gas diffusivities describes the diffusivity in molten Al and Cu. We report generalized analytic models for the self-diffusivities and interdiffusivity (mutual diffusivity) that fit the MD results well. The MD-derived transport coefficients are in good agreement with the available experimental data. We also report MD calculations of the viscosity and an analytic fit to those results. The ionic thermal conductivity is discussed briefly.

Multimodal pediatric pain management (part 2).

PubMed

Friedrichsdorf, Stefan J

2017-05-01

Dr Stefan Friedrichsdorf speaks to Commissioning Editor Jade Parker: Stefan Friedrichsdorf, MD, is medical director of the Department of Pain Medicine, Palliative Care and Integrative Medicine at Children's Hospitals and Clinics of Minnesota in Minneapolis/St Paul, MN, USA, home to one of the largest and most comprehensive programs of its kind in the country. The pain and palliative care program is devoted to control acute, chronic/complex and procedural pain for inpatients and outpatients in close collaboration with all pediatric subspecialties at Children's Minnesota. The team also provides holistic, interdisciplinary care for children and teens with life limiting or terminal diseases and their families. Integrative medicine provides and teaches integrative, nonpharmacological therapies (such as massage, acupuncture/acupressure, biofeedback, aromatherapy and self-hypnosis) to provide care that promotes optimal health and supports the highest level of functioning in all individual children's activities. In this second part of the interview they discuss multimodal (opioid-sparing) analgesia for hospitalized children in pain and how analgesics and adjuvant medications, interventions, rehabilitation, psychological and integrative therapies act synergistically for more effective pediatric pain control with fewer side effects than a single analgesic or modality.

Self-diffusivity and interdiffusivity of molten aluminum-copper alloys under pressure, derived from molecular dynamics

NASA Astrophysics Data System (ADS)

Rudd, Robert E.; Cabot, William H.; Caspersen, Kyle J.; Greenough, Jeffrey A.; Richards, David F.; Streitz, Frederick H.; Miller, Paul L.

2012-03-01

We use molecular dynamics (MD) to simulate diffusion in molten aluminum-copper (AlCu) alloys. The self-diffusivities and Maxwell-Stefan diffusivities are calculated for AlCu mixtures using the Green-Kubo formulas at temperatures from 1000 to 4000 K and pressures from 0 to 25 GPa, along with additional points at higher temperatures and pressures. The diffusivities are corrected for finite-size effects. The Maxwell-Stefan diffusivity is compared to the diffusivity calculated from the self-diffusivities using a generalization of the Darken equation. We find that the effects of cross-correlation are small. Using the calculated self-diffusivities, we have assessed whether dilute hard-sphere and dilute Lennard-Jones models apply to the molten mixture. Neither of the two dilute gas diffusivities describes the diffusivity in molten Al and Cu. We report generalized analytic models for the self-diffusivities and interdiffusivity (mutual diffusivity) that fit the MD results well. The MD-derived transport coefficients are in good agreement with the available experimental data. We also report MD calculations of the viscosity and an analytic fit to those results. The ionic thermal conductivity is discussed briefly.

Evidence of high-elevation amplification versus Arctic amplification

PubMed Central

Wang, Qixiang; Fan, Xiaohui; Wang, Mengben

2016-01-01

Elevation-dependent warming in high-elevation regions and Arctic amplification are of tremendous interest to many scientists who are engaged in studies in climate change. Here, using annual mean temperatures from 2781 global stations for the 1961–2010 period, we find that the warming for the world’s high-elevation stations (>500 m above sea level) is clearly stronger than their low-elevation counterparts; and the high-elevation amplification consists of not only an altitudinal amplification but also a latitudinal amplification. The warming for the high-elevation stations is linearly proportional to the temperature lapse rates along altitudinal and latitudinal gradients, as a result of the functional shape of Stefan-Boltzmann law in both vertical and latitudinal directions. In contrast, neither altitudinal amplification nor latitudinal amplification is found within the Arctic region despite its greater warming than lower latitudes. Further analysis shows that the Arctic amplification is an integrated part of the latitudinal amplification trend for the low-elevation stations (≤500 m above sea level) across the entire low- to high-latitude Northern Hemisphere, also a result of the mathematical shape of Stefan-Boltzmann law but only in latitudinal direction. PMID:26753547

Nonlinear Interaction of the Beat-Photon Beams with the Brain Neurocenters: Laser Neurophysics

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2010-03-01

I propose a novel mechanism for laser-brain interaction: Nonlinear interaction of ultrashort pulses of beat-photon, (φ1-- φ2), or double-photon, (φ1+φ2), footnotetextMaria Goeppert-Mayer, "Uber Elementarakte mit zwei Quantenspr"ungen, Ann Phys 9, 273, 95. (1931). beams with the corrupted brain neurocenters, causing a particular neurological disease. The open-scull cerebral tissue can be irradiated with the beat-photon pulses in the range of several 100s fs, with the laser irradiances in the range of a few mW/cm^2, repetition rate of a few 100s Hz, and in the frequency range of 700-1300nm generated in the beat-wave driven free electron laser.footnotetextV. Alexander Stefan, The Interaction of Photon Beams with the DNA Molecules: Genomic Medical Physics. American Physical Society, 2009 APS March Meeting, March 16-20, 2009, abstract #K1.276; V. Stefan, B. I. Cohen, and C. Joshi, Nonlinear Mixing of Electromagnetic Waves in Plasmas Science 27 January 1989:Vol. 243. no. 4890, pp. 494 -- 500 (January 1989). This method may prove to be an effective mechanism in the treatment of neurological diseases: Parkinson's, Lou Gehrig's, and others.

Finite temperature behavior of the CPT-even and parity-even electrodynamics of the standard model extension

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

Casana, Rodolfo; Ferreira, Manoel M. Jr; Rodrigues, Josberg S.

2009-10-15

In this work, we examine the finite temperature properties of the CPT-even and Lorentz-invariance-violating (LIV) electrodynamics of the standard model extension, represented by the term W{sub {alpha}}{sub {nu}}{sub {rho}}{sub {phi}}F{sup {alpha}}{sup {nu}}F{sup {rho}}{sup {phi}}. We begin analyzing the Hamiltonian structure following the Dirac's procedure for constrained systems and construct a well-defined and gauge invariant partition function in the functional integral formalism. Next, we specialize for the nonbirefringent coefficients of the tensor W{sub {alpha}}{sub {nu}}{sub {rho}}{sub {phi}}. In the sequel, the partition function is explicitly carried out for the parity-even sector of the tensor W{sub {alpha}}{sub {nu}}{sub {rho}}{sub {phi}}. The modifiedmore » partition function is a power of the Maxwell's partition function. It is observed that the LIV coefficients induce an anisotropy in the black body angular energy density distribution. The Planck's radiation law, however, retains its frequency dependence and the Stefan-Boltzmann law keeps the usual form, except for a change in the Stefan-Boltzmann constant by a factor containing the LIV contributions.« less

Engage the Media: The Coast Guard’s Public Affairs Posture during the Response to Hurricane Katrina

DTIC Science & Technology

2007-03-01

21 Stefan Lovgren, “CSI Effect’ Is Mixed Blessing for Real Crime Labs,” National Geographic News (Washington...media market in western Kentucky and dominated the news for three days. The stakeholders (e.g., the investigators, the relatives, the townspeople and...Gather as much video as you can Market those visuals to the media Try to get media embedded with you—offer opportunities to media as

Middle-Class Consensus, Social Capital and the Mechanics of Economic Development

DTIC Science & Technology

2005-01-01

Michael, Social Capital and Regional Mobility, Nr. 4/2002. "* Schdfer, Wolf, EU-Erweiterung: Anmerkungen zum Balassa - Samuelson -Effekt, Nr. 3/2002...variations, while the argument of both the present paper and most of the previous literature on inequality and growth refers to long-run growth effects of...Diskussionsbeitriige zur Finanzwissenschaft " Josten, Stefan, Crime, Inequality, and Economic Growth. A Classical Argument for Distributional Equality

Religious Accommodation for Military Members in the Twenty-First Century

DTIC Science & Technology

2012-02-01

order and discipline is speculative. He presented a scenario where a female Airman had permission to wear her hijab indoors. When she transferred to the...Lieutenant Colonel, USAF A Research Report Submitted to the Faculty In Partial Fulfillment of the Graduation Requirements Advisor: Dr. Stefan Eisen, Jr...Colonel, USAF (Retired) Maxwell Air Force Base, Alabama February 2012 DISTRIBUTION A . Approved for public release: distribution unlimited 2

Service Level Agreements in Service-Oriented Architecture Environments

DTIC Science & Technology

2008-09-01

the WS-Agreement [ Seidel 2007]. Indeed, core concepts of the WSLA were brought into the WS-Agreement, which also contains ideas from the Service...A Categorization Scheme for SLA Metrics. http://ibis.in.tum.de/staff/paschke/docs/MKWI2006_SLA_Paschke.pdf (2006). [ Seidel 2007] Seidel , Jan...addr-metadata-20070731/(2007). [Wohlstadter 2004] Wohlstadter, Eric; Tai, Stefan ; Mikalsen, Thomas; Rouvellou, Isabelle; & Devanbu, Premkumar

Development of a Novel Hybrid Multi-Junction Architecture for Silicon Solar Cells

DTIC Science & Technology

2015-03-26

W Watts KOH Potassium Hydroxide xj Junction depth k Thermal conductivity z Normal distance l Conductor length σ Stefan...outermost orbit [9]. A material conducts electricity when its valence electrons move into the conduction band and become conductor electrons. Conductor ...become a conductor , it must absorb enough energy to overcome the band gap, which is the energy difference between the valence band and the conduction

Effect of soil property uncertainties on permafrost thaw projections: a calibration-constrained analysis

NASA Astrophysics Data System (ADS)

Harp, D. R.; Atchley, A. L.; Painter, S. L.; Coon, E. T.; Wilson, C. J.; Romanovsky, V. E.; Rowland, J. C.

2016-02-01

The effects of soil property uncertainties on permafrost thaw projections are studied using a three-phase subsurface thermal hydrology model and calibration-constrained uncertainty analysis. The null-space Monte Carlo method is used to identify soil hydrothermal parameter combinations that are consistent with borehole temperature measurements at the study site, the Barrow Environmental Observatory. Each parameter combination is then used in a forward projection of permafrost conditions for the 21st century (from calendar year 2006 to 2100) using atmospheric forcings from the Community Earth System Model (CESM) in the Representative Concentration Pathway (RCP) 8.5 greenhouse gas concentration trajectory. A 100-year projection allows for the evaluation of predictive uncertainty (due to soil property (parametric) uncertainty) and the inter-annual climate variability due to year to year differences in CESM climate forcings. After calibrating to measured borehole temperature data at this well-characterized site, soil property uncertainties are still significant and result in significant predictive uncertainties in projected active layer thickness and annual thaw depth-duration even with a specified future climate. Inter-annual climate variability in projected soil moisture content and Stefan number are small. A volume- and time-integrated Stefan number decreases significantly, indicating a shift in subsurface energy utilization in the future climate (latent heat of phase change becomes more important than heat conduction). Out of 10 soil parameters, ALT, annual thaw depth-duration, and Stefan number are highly dependent on mineral soil porosity, while annual mean liquid saturation of the active layer is highly dependent on the mineral soil residual saturation and moderately dependent on peat residual saturation. By comparing the ensemble statistics to the spread of projected permafrost metrics using different climate models, we quantify the relative magnitude of soil

PREFACE: 6th International Workshop on Multi-Rate Processes and Hysteresis (MURPHYS2012)

NASA Astrophysics Data System (ADS)

Dimian, Mihai; Rachinskii, Dmitrii

2015-02-01

The International Workshop on Multi-Rate Processes and Hysteresis (MURPHYS) conference series focuses on multiple scale systems, singular perturbation problems, phase transitions and hysteresis phenomena occurring in physical, biological, chemical, economical, engineering and information systems. The 6th edition was hosted by Stefan cel Mare University in the city of Suceava located in the beautiful multicultural land of Bukovina, Romania, from May 21 to 24, 2012. This continued the series of biennial multidisciplinary conferences organized in Cork, Ireland from 2002 to 2008 and in Pécs, Hungary in 2010. The MURPHYS 2012 Workshop brought together more than 50 researchers in hysteresis and multi-scale phenomena from the United State of America, the United Kingdom, France, Germany, Italy, Ireland, Czech Republic, Hungary, Greece, Ukraine, and Romania. Participants shared and discussed new developments of analytical techniques and numerical methods along with a variety of their applications in various areas, including material sciences, electrical and electronics engineering, mechanical engineering and civil structures, biological and eco-systems, economics and finance. The Workshop was sponsored by the European Social Fund through Sectoral Operational Program Human Resources 2007-2013 (PRO-DOCT) and Stefan cel Mare University, Suceava. The Organizing Committee was co-chaired by Mihai Dimian from Stefan cel Mare University, Suceava (Romania), Amalia Ivanyi from the University of Pecs (Hungary), and Dmitrii Rachinskii from the University College Cork (Ireland). All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing. The Guest Editors wish to place on record their sincere gratitude to Miss Sarah Toms for the assistance she provided

The Federal Republic of Germany and Left Wing Terrorism

DTIC Science & Technology

2003-12-01

Stoll, Peter Jurgen Boock, Susan Albrecht, Rolf Clemens Wagner, and Stefan Wisniewski. 49 Merkl , p. 199. 50 Ibid, p. 192. 51 Hans-Joachim Klein...during each 2 Peter H. Merkl , “Rollerball or Neo-Nazi Violence?,” in Peter H. Merkl (ed...commitment to non-violence is hypocritical.”28 Peter Merkl described the situation best when he said, “Terrorism, of course is not the logical result of

Election Verifiability: Cryptographic Definitions and an Analysis of Helios and JCJ

DTIC Science & Technology

2015-04-01

anonymous credentials. In CSF’14: 27th Computer Security Foundations Symposium. IEEE Computer Society, 2014. To appear. [22] David Chaum . Untraceable...electronic mail, return addresses, and digital pseudonyms. Communications of the ACM, 24(2):84–88, 1981. [23] David Chaum . Secret-ballot receipts...True voter-verifiable elections. IEEE Security and Privacy, 2(1):38–47, 2004. [24] David Chaum , Richard Carback, Jeremy Clark, Aleksander Essex, Stefan

Mobile Number Portability in Europe

DTIC Science & Technology

2005-08-01

Anmerkungen zum Balassa - Samuelson -Effekt, Nr. 3/2002, erschienen in: Stefan Reitz (Hg.): Theoretische und wirtschaftspolitische Aspekte der internatio- nalen...However, the argument is slightly more complex. Using a simple model with differentiated networks, Buehler and Haucap (2004) show that the incumbent’s...Elasticities The above arguments suggest that it is more difficult to gain market share in the presence of switching costs, as undercutting needs to be

Unanimous Constitutional Consent and the Immigration Problem

DTIC Science & Technology

2004-12-01

Wolf, EU-Erweiterung: Anmerkungen zum Balassa - Samuelson -Effekt, Nr. 3/2002, erschienen in: Stefan Reitz (Hg.): Theoretische und wirtschafispolitische...the individualistic norm. Their main argument is that the contradiction between collective coercion and individual freedom cannot be dissolved at the... arguments against this way of reasoning for there usually will be holes in that veil, so that it may be possible to draw conclusions from the past with

Symbolic Dynamics and Grammatical Complexity

NASA Astrophysics Data System (ADS)

Hao, Bai-Lin; Zheng, Wei-Mou

The following sections are included: * Formal Languages and Their Complexity * Formal Language * Chomsky Hierarchy of Grammatical Complexity * The L-System * Regular Language and Finite Automaton * Finite Automaton * Regular Language * Stefan Matrix as Transfer Function for Automaton * Beyond Regular Languages * Feigenbaum and Generalized Feigenbaum Limiting Sets * Even and Odd Fibonacci Sequences * Odd Maximal Primitive Prefixes and Kneading Map * Even Maximal Primitive Prefixes and Distinct Excluded Blocks * Summary of Results

Multidisciplinary Thermal Analysis of Hot Aerospace Structures

DTIC Science & Technology

2010-05-02

Seidel iteration. Such a strategy simplifies explicit/implicit treatment , subcycling, load balancing, software modularity, and replacements as better... Stefan -Boltzmann constant , E is the emissivity of the surface, f is the form factor from the surface to the reference surface, Br is the temperature of...Stokes equations using Gauss- Seidel line Relaxation, Computers and Fluids, 17, pp.l35-150, 1989. [22] Hung C.M. and MacCormack R.W., Numerical

Dynamical Systems Theory and Lagrangian Data Assimilation in Geophysical Fluid Dynamics FY 2013 (October 1, 2012 - September 30, 2013)

DTIC Science & Technology

2013-09-30

unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 2 Co-PI: Christopher K. R. T. Jones ...Co-PI: Stefan Llewellyn Smith Department of Mechanical and Aerospace Engineering University of California, San Diego 9500 Gilman Drive La...systems but looking a weakly 3D systems for long time intervals. ( Llewellyn Smith) Figure 10. We are exploring the effects of submesoscale motions

Nonlinear diffusion equations as asymptotic limits of Cahn-Hilliard systems on unbounded domains via Cauchy's criterion

NASA Astrophysics Data System (ADS)

Fukao, Takeshi; Kurima, Shunsuke; Yokota, Tomomi

2018-05-01

This paper develops an abstract theory for subdifferential operators to give existence and uniqueness of solutions to the initial-boundary problem (P) for the nonlinear diffusion equation in an unbounded domain $\\Omega\\subset\\mathbb{R}^N$ ($N\\in{\\mathbb N}$), written as \\[ \\frac{\\partial u}{\\partial t} + (-\\Delta+1)\\beta(u) = g \\quad \\mbox{in}\\ \\Omega\\times(0, T), \\] which represents the porous media, the fast diffusion equations, etc., where $\\beta$ is a single-valued maximal monotone function on $\\mathbb{R}$, and $T>0$. Existence and uniqueness for (P) were directly proved under a growth condition for $\\beta$ even though the Stefan problem was excluded from examples of (P). This paper completely removes the growth condition for $\\beta$ by confirming Cauchy's criterion for solutions of the following approximate problem (P)$_{\\varepsilon}$ with approximate parameter $\\varepsilon>0$: \\[ \\frac{\\partial u_{\\varepsilon}}{\\partial t} + (-\\Delta+1)(\\varepsilon(-\\Delta+1)u_{\\varepsilon} + \\beta(u_{\\varepsilon}) + \\pi_{\\varepsilon}(u_{\\varepsilon})) = g \\quad \\mbox{in}\\ \\Omega\\times(0, T), \\] which is called the Cahn--Hilliard system, even if $\\Omega \\subset \\mathbb{R}^N$ ($N \\in \\mathbb{N}$) is an unbounded domain. Moreover, it can be seen that the Stefan problem is covered in the framework of this paper.

Four steps to eliminate or reduce pain in children caused by needles (part 1).

PubMed

Friedrichsdorf, Stefan J

2017-03-01

Dr Stefan Friedrichsdorf speaks to Jade Parker, Commissioning Editor: Stefan J Friedrichsdorf, MD, is medical director of the Department of Pain Medicine, Palliative Care and Integrative Medicine at Children's Hospitals and Clinics of Minnesota, Minneapolis/St Paul, MN, USA, home to one of the largest and most comprehensive programs of its kind in the country. The interdisciplinary pain team is devoted to prevent and treat acute, procedural, neuropathic, psycho-social-spiritual, visceral, and chronic/complex pain for all inpatients and outpatients in close collaboration with all pediatric subspecialties at Children's Minnesota. The palliative care team also provides holistic care for pediatric patients with life-threatening diseases and adds an extra layer of support to the care of children with serious illness and their families. Integrative medicine provides and teaches integrative ('non-pharmacological') therapies, such as massage, acupuncture/acupressure, biofeedback, aromatherapy and self-hypnosis, to provide care that promotes optimal health and supports the highest level of functioning in all individual children's activities. Children's Minnesota became the first children's hospital to system-wide implement a "Children's Comfort Promise: We promise to do everything to prevent and treat pain," resulting in decrease or elimination of needle pain caused by vaccinations, blood draws, intravenous access, and injections in more than 200,000 children annually.

Crystallization of glass-forming liquids: Specific surface energy

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

Schmelzer, Jürn W. P., E-mail: juern-w.schmelzer@uni-rostock.de; Abyzov, Alexander S.

2016-08-14

A generalization of the Stefan-Skapski-Turnbull relation for the melt-crystal specific interfacial energy is developed in terms of the generalized Gibbs approach extending its standard formulation to thermodynamic non-equilibrium states. With respect to crystal nucleation, this relation is required in order to determine the parameters of the critical crystal clusters being a prerequisite for the computation of the work of critical cluster formation. As one of its consequences, a relation for the dependence of the specific surface energy of critical clusters on temperature and pressure is derived applicable for small and moderate deviations from liquid-crystal macroscopic equilibrium states. Employing the Stefan-Skapski-Turnbullmore » relation, general expressions for the size and the work of formation of critical crystal clusters are formulated. The resulting expressions are much more complex as compared to the respective relations obtained via the classical Gibbs theory. Latter relations are retained as limiting cases of these more general expressions for moderate undercoolings. By this reason, the formulated, here, general relations for the specification of the critical cluster size and the work of critical cluster formation give a key for an appropriate interpretation of a variety of crystallization phenomena occurring at large undercoolings which cannot be understood in terms of the Gibbs’ classical treatment.« less

Dynamic Confinement of ITER Plasma by O-Mode Driver at Electron Cyclotron Frequency Range

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2009-05-01

A low B-field side launched electron cyclotron O-Mode driver leads to the dynamic rf confinement, in addition to rf turbulent heating, of ITER plasma. The scaling law for the local energy confinement time τE is evaluated (τE ˜ 3neTe/2Q, where (3/2) neTe is the local plasma thermal energy density and Q is the local rf turbulent heating rate). The dynamics of unstable dissipative trapped particle modes (DTPM) strongly coupled to Trivelpiece-Gould (T-G) modes is studied for gyrotron frequency 170GHz; power˜24 MW CW; and on-axis B-field ˜ 10T. In the case of dynamic stabilization of DTPM turbulence and for the heavily damped T-G modes, the energy confinement time scales as τE˜(I0)-2, whereby I0(W/m^2) is the O-Mode driver irradiance. R. Prater et. al., Nucl. Fusion 48, No 3 (March 2008). E. P. Velikhov, History of the Russian Tokamak and the Tokamak Thermonuclear Fusion Research Worldwide That Led to ITER (Documentary movie; Stefan Studios Int'l, La Jolla, CA, 2008; E. P. Velikhov, V. Stefan.) M N Rosenbluth, Phys. Scr. T2A 104-109 1982 B. B. Kadomtsev and O. P. Pogutse, Nucl. Fusion 11, 67 (1971).

Processor Capacity Reserves for Multimedia Operating Systems

DTIC Science & Technology

1993-05-01

Stefan Savage, and -ideyuki Tokuda May 1993 CMU-CS-93-157 School of Computer Science Camegie Mellon University Pittsburgh, PA 15213 Abstract Multimedia...and provide feedback so that the estimate can be adjusted if necessaty . For non-periodic activities that are to be limited by a processor percentage...comments and suggestions: Brian Bershad, Ragunathan Rajkumar, and the members of the ART group and Mach group at CMU. 13 References [1] D. P

Effect of Convection on Weld Pool Shape and Microstructure.

DTIC Science & Technology

1986-07-01

latent heat of fusion 11 u dynamic viscosity Iwo V kinematic viscosity P density a Stefan -Boltzman constant stress tensor 0, functions defined the...and temperature. The convections for velocities and temperature are based on a mixed Gauss- -* Seidel and Jacobi schemes, proceeding from line-to...line according to the Gauss- Seidel scheme, updating values as each line is completed. With each line, however, the point-by-point iteration is based on

Heat transfer in damaged material

NASA Astrophysics Data System (ADS)

Kruis, J.

2013-10-01

Fully coupled thermo-mechanical analysis of civil engineering problems is studied. The mechanical analysis is based on damage mechanics which is useful for modeling of behaviour of quasi-brittle materials, especially in tension. The damage is assumed to be isotropic. The heat transfer is assumed in the form of heat conduction governed by the Fourier law and heat radiation governed by the Stefan-Boltzmann law. Fully coupled thermo-mechanical problem is formulated.

Plunge location of sediment driven hyperpycnal river discharges considering bottom friction, lateral entrainment, and particle settling

NASA Astrophysics Data System (ADS)

Strom, K. B.; Bhattacharya, J.

2012-12-01

River discharges with very high sediment loads have the potential to develop into plunging hyperpycnal flows that transition from a river jet to a turbidity current at some location basinward of the river mouth due to the density difference between the turbid river and the receiving water body. However, even if the bulk density of the turbid river is greater than that of the receiving lake or ocean, some distance is needed for the forward inertia of the river to dissipate so that the downward gravitational pull can cause the system to collapse into a subaqueous turbidity current. This collapsing at the plunge point has been found to occur when the densimetric Froude number decreases to a value between 0.3 < Frd < 0.7 (Fang and Stefan 2000, Parker and Toniolo 2007, Dai and Garcia 2010, Lamb et al. 2010). In 2D channel flow analysis at the plunge point, this has led to the concept of a two-fold criterion for plunging. The first is simply for the need of high enough suspended sediment concentration to overcome the density difference between the river fluid and the fluid of the receiving water. The second is the need for sufficiently deep water to reduce the densimetric Froude below the critical value for plunging, which leads to dependence of plunging on the receiving water basin topography (Lamb et al. 2010). In this analysis, we expand on past work by solving a system of ODE river jet equations to account for bottom friction, lateral entrainment of ambient fluid, and particle settling between the river mouth and the plunge location. Typical entrainment and bottom friction coefficients are used and the model is tested against the laboratory density current data of Fang and Stefan (1991). A suite of conditions is solved with variable river discharge velocity, aspect ratio, suspended sediment concentration, and particle size; a range of salinity values and bottom slopes are used for the receiving water body. The plunge location is then expressed as a function of the

Quark Matter 2011 (QM11) Quark Matter 2011 (QM11)

NASA Astrophysics Data System (ADS)

2011-12-01

International Advisory Committee Antinori, FedericoPaic, Guy Braun-Munzinger, PeterPajares, Carlos Cifarelli, LuisaPeitzmann, Thomas Erazmus, BarbaraRedlich, Krzysztof Eskola, KariRiccati, Lodovico Gaardhøje, Jens JørgenRoland, Gunther Gale, CharlesRoy, Christelle Gelis, FrancoisSchukraft, Jürgen Giubellino, PaoloSinha, Bikash Greiner, CarstenSrivastava, Dinesh Gyulassy, MiklosStachel, Johanna Harris, JohnSteinberg, Peter Hatsuda, TetsuoStroth, Joachim Heinz, UlrichSugitate, Toru Jacak, BarbaraTserruya, Itzhak Karsch, FrithjofVelkovska, Julia Kharzeev, DimaWang, Enke Kodama, TakeshiWang, Xin, Nian Lévai, PéterWessels, Johannes Manko, VladislavXu, Nu Müller, BerndtZajc, William Ollitrault, Jean-Yves Organizing Committee Arleo, FrancoisDupieux, Pascal Bastid, NicoleFurget, Christophe Bourgeois, Marie-LaureGranier de Cassagnac, Raphael Bregant, MarcoGuernane, Rachid Carminati, FedericoHervet, Carnita Castillo, JavierKuhn, Christian Cheynis, BrigitteOlivier, Nathalie Conesa, DelValle, Zaida Connor, MichelleRenshall, Lucy Crochet, PhilippeSuire, Christophe Delagrange, HuguesTihinen, Ulla Program Committee Schutz, Yves (Chair)Baldisseri, Alberto Wiedemann, Urs (co-Chair)Safarik, Karel Aurenche, Patrick

Influence of Embedded Optical Fibers on Compressive Strength of Advanced Composites

DTIC Science & Technology

1993-12-01

Aeronautial Engineering Accesion For NTIS CRA&,j DTIC TAB 13 Unawlou:,ced Justification Stefan B. Dosedel, B.S.M.E. By _i l b i...aircraft weight can yield an increase in specific excess power of 1%, an increase in subsonic sustained turn rate of 1%, and an increase in supersonic... sustained turn rate of .5% [2]. Composite materials can achieve mass savings on the order of 9-30 percent [2]. It is expected that composite materials will

INTERNATIONAL CONFERENCE ON SEMICONDUCTOR INJECTION LASERS SELCO-87: Transient heat conduction in laser diodes

NASA Astrophysics Data System (ADS)

Enders, P.; Galley, J.

1988-11-01

The dynamics of heat transfer in stripe GaAlAs laser diodes is investigated by solving the linear diffusion equation for a quasitwo-dimensional multilayer structure. The calculations are rationalized drastically by the transfer matrix method and also using for the first time the asymptotes of the decay constants. Special attention is given to the convergence of the Fourier series. A comparison with experimental results reveals however that this is essentially the Stefan problem (with moving boundary conditions).

Sustainability Gaps in Municipal Solid Waste Management: The Case of Landfills

DTIC Science & Technology

2006-02-01

Regional Mobility, Nr. 4/2002. "* Schafer, Wolf, EU-Erweiterung: Anmerkungen zum Balassa - Samuelson -Effekt, Nr. 3/2002, erschienen in: Stefan Reitz (Hg...generations with high long-term external costs as it is the case in the dry tomb technology. Besides the efficiency aspect an argument of justice is... argument of time- consistency according to Strotz does not play any role because the assumed "rational" way of planning cannot be realized due to the non

Functionalization and Passivation of Boron Nanoparticles with a Hypergolic Ionic Liquid (Pre-Print)

DTIC Science & Technology

2012-04-01

Department of Chemistry , University of Utah, 315 S 1400 E, Salt Lake City, UT 84112, USA Stefan Schneider3, Jerry Boatz4 and Tom Hawkins5 Propellants...USA Parker D. McCrary6, Preston A. Beasley6, Steven P. Kelley6 and Robin D. Rogers7 Center for Green Manufacturing and Department of Chemistry ... Chemistry , The University of Utah, 315 S. 1400 E., Rm. b107, Salt Lake City, UT 84112, USA. 2 Principal Investigator and Professor, Department of

Energy Barriers and Hysteresis in Martensitic Phase Transformations

DTIC Science & Technology

2008-08-01

glacial acetic acid (CH3COOH) and 10-15% perchloric acid (HCLO4) by volume, the cathode was stainless steel , the anode was stainless steel or Ti, the...Submitted to Acta Materialia Energy barriers and hysteresis in martensitic phase transformations Zhiyong Zhang, Richard D. James and Stefan Müller...hysteresis based on the growth from a small scale of fully developed austenite martensite needles. In this theory the energy of the transition layer plays a

Ciscoes (Coregonus, subgenus Leucichthys) of the Laurentian Great Lakes and Lake Nipigon

USGS Publications Warehouse

Eshenroder, Randy L.; Vecsei, Paul; Gorman, Owen T.; Yule, Daniel; Pratt, Thomas C.; Mandrak, Nicholas E.; Bunnell, David B.; Muir, Andrew M.

2016-01-01

This study of the ciscoes (Coregonus, subgenus Leucichthys) of the Great Lakes and Lake Nipigon represents a furtherance through 2015 of field research initiated by Walter Koelz in 1917 and continued by Stanford Smith in the mid-1900s—a period spanning nearly a century. Like Koelz’s study, this work contains information on taxonomy, geographical distribution, ecology, and status of species (here considered forms). Of the seven currently recognized forms (C. artedi, C. hoyi, C. johannae, C. kiyi, C. nigripinnis, C. reighardi, and C. zenithicus) described by Koelz as major in his 1929 monograph, two (C. johannae and C. reighardi) are extinct. In addition, C. alpenae, described by Koelz but subsequently synonymized with C. zenithicus, although extinct, is recognized as valid making a total of eight major forms. Six of these forms, all but C. artedi and C. hoyi, have been lost from Lake Michigan, and seven have been lost from Lake Huron, leaving in Lake Huron only C. artedi and an introgressed deepwater form that we term a hybrid swarm. C. artedi appears, like its sister form C. alpenae, to have been lost from Lake Erie. Only C. artedi remains extant in Lake Ontario, its three sister forms (C. hoyi, C. kiyi, and C. reighardi) having disappeared long ago.Lakes Superior and Nipigon have retained their original species flocks consisting of four forms each: C. artedi, C. hoyi, and C. zenithicus in both lakes; C. kiyi in Lake Superior; and C. nigripinnis in Lake Nipigon. Morphological deviations from the morphotypes described by Koelz have been modest in contemporary samples. Overall, C. kiyi and C. artedi were the most morphologically stable forms while C. hoyi, C. nigripinnis, and C. zenithicus were the least stable. Although contemporary populations of C. artedi from Lakes Michigan and Huron are highly diverged from the morphotypes described by Koelz, the contemporary samples were of undescribed deep-bodied forms unlikely to have been sampled by Koelz because of

Bibliography on Cold Regions Science and Technology. Volume 33, Part 1 and Part 2

DTIC Science & Technology

1979-12-01

334020 (1978, p 4.10, ruas 33-2685 young sea ice. Niedrauer, T.M., et a ). t1979, High speed tunneling. Tnrasiugin, A , (1978, p.10-t1I, rust Manual fnr...resist- tions In the western High Arctic. Snowi loatd Roofes Sgnowpyis no cu a ance, Test equipment. Bliss, LC., ed, Canada, Arctic Land Use Research toi...permafrost foundation of a Effect of cryogenous processes on the stability of high Numerical solution of problems of the Stefan type for multispsa industrial

Application of temporal LNC logic in artificial intelligence

NASA Astrophysics Data System (ADS)

Adamek, Marek; Mulawka, Jan

2016-09-01

This paper presents the temporal logic inference engine developed in our university. It is an attempt to demonstrate implementation and practical application of temporal logic LNC developed in Cardinal Stefan Wyszynski University in Warsaw.1 The paper describes the fundamentals of LNC logic, architecture and implementation of inference engine. The practical application is shown by providing the solution for popular in Artificial Intelligence problem of Missionaries and Cannibals in terms of LNC logic. Both problem formulation and inference engine are described in details.

Hysteresis and Phase Transitions in a Lattice Regularization of an Ill-Posed Forward-Backward Diffusion Equation

NASA Astrophysics Data System (ADS)

Helmers, Michael; Herrmann, Michael

2018-03-01

We consider a lattice regularization for an ill-posed diffusion equation with a trilinear constitutive law and study the dynamics of phase interfaces in the parabolic scaling limit. Our main result guarantees for a certain class of single-interface initial data that the lattice solutions satisfy asymptotically a free boundary problem with a hysteretic Stefan condition. The key challenge in the proof is to control the microscopic fluctuations that are inevitably produced by the backward diffusion when a particle passes the spinodal region.

Symposium KK: Structure-Property Relationships in Biomineralized and Bio-mimetic Composites

DTIC Science & Technology

2010-04-06

Preventive and Restorative Dental Sciences, UCSF, San Francisco, California. 4:45 PM KK2.8 Damage and Crack Evolution in Mammalian Enamel James Jin...Technology, Graz, Austria. 9:45AMKK6.S AFM and PFM measurements of Enamel in order to Determine the Crack Tip Toughness and Cohesive Zone of Enamel Gerold...11:00 AM KK9.7 Enamel Matrix Guided Growth of Apatite Vuk Uskokovic1. Li Zhu2, Wu Li2 and Stefan Habelitz1; ’Department of Preventive and

WIS Implementation Study Report. Volume 1. Main Report.

DTIC Science & Technology

1983-10-01

Luenberger, Prof. David G. * Stanford University Ries, Dr. Daniel R. * Computer Corporation of America Schill, John Naval Ocean Systems Center Shrier , Dr...Robert E. 43 Kaczmarek, Dr. Thomas S. 45 Klein, Dr. Stanely A. 47 Kramer, Dr. John F. 49 Larsen, Dr. Robert E. 55 Luenberger, Prof. David G. 58...Riddle, Dr. William E. 76 Ries, Dr. Daniel R. 82 Sapp, Mr. John W. 88 Shelley, Mr. Stephen H. 89 Shrier , Dr. Stefan 94 Slusarczuk, Dr. Marko M.G. 96

A Closely Coupled Experimental and Numerical Approach for Hypersonic and High Enthalpy Flow Investigations Utilising the HEG Shock Tunnel and the DLR TAU Code

DTIC Science & Technology

2010-04-01

factorization scheme (Lower-Upper Symmetric Gauss- Seidel ) can be used for time integration. Additional convergence acceleration is achieved by the...of the full Stefan -Maxwell equations. The diffusive mass flux of species S is computed according to: for 1 for jS S S Sm j jm S j eS jd S S S j j j...approximate factorization scheme (Lower-Upper Symmetric Gauss- Seidel ). For steady state problems, equation (69) reduces to R=0 because ddU t

Modelling Phase Transition Phenomena in Fluids

DTIC Science & Technology

2015-07-01

Sublimation line r @@I Triple point ? Vapourisation liner @@I Critical point -Fusion line Solid Liquid Gas Figure 1: Schematic of a phase diagram means that the...velocity field can be set zero, and only the balance of energy constitutes the Stefan model. In contrast to this the liquid - gas phase transitions...defined by requiring that the phase-transition line is crossed in a direction from solid to liquid or from liquid to gas (vapour) phases. The term T∗ δs is

The Brain Physics: Multi Laser Beam Interaction with the Brain Topions (the Brain Neurocenters)

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2015-03-01

A novel method for the treatment of the neurological diseases is proposed. The multiple-energy laser photons (the blue scanning photons and ultraviolet focusing photons) interact with the specific DNA molecules within the topion (such as Parkinson's and Alzheimer's brain topion) via the matching of laser frequency with the oscillation eigen-frequency of a particular molecule within the DNA. In this way, the corrupt molecules (the structure of molecules) can be manipulated so as to treat (eliminate) the neurological disease. Supported by Nikola Tesla Labs, Stefan University.

2015 Laser Diagnostics in Combustion Gordon Research Conference and Gordon Research Seminar

DTIC Science & Technology

2015-10-20

34Ultra-Short Nonlinear Sensors : Exploiting Electronic Resonances" 9:50 am - 10:00 am Discussion 10:00 am - 10:30 am Coffee Break 10:30 am - 11:10 am...Chair 7:30 pm - 9:30 pm Advances in Sources and Sensors Discussion Leader: Jacqueline O’Connor (Pennsylvania State University, USA) 7:30 pm - 7:40...Cameras" 9:15 pm - 9:30 pm Discussion Thursday 7:30 am - 8:30 am Breakfast 9:00 am - 12:30 pm Soot Particle Detection Discussion Leader: Stefan Will

Enhancing radiative energy transfer through thermal extraction

NASA Astrophysics Data System (ADS)

Tan, Yixuan; Liu, Baoan; Shen, Sheng; Yu, Zongfu

2016-06-01

Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a). In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics. Thermal extraction works by using a specially designed thermal extractor to convert and guide the near-field energy to the far field, as shown in Fig. 1b. The same blackbody as shown in Fig. 1a is placed closely below the thermal extractor with a spacing smaller than the thermal wavelength. The near-field coupling transfers radiative energy with a density greater than σT4. The thermal extractor, made from transparent and high-index or structured materials, does not emit or absorb any radiation. It transforms the near-field energy and sends it toward the far field. As a result, the total amount of far-field radiative heat dissipated by the same blackbody is greatly enhanced above SσT4, where S is the area of the emitter. This paper will review the progress in thermal

AURORA: The Next Generation Space Weather Sensor for NPOESS

NASA Astrophysics Data System (ADS)

Paxton, L.; Morrison, D.; Santo, A.; Ogorzalek, B.; Goldsten, J.; Boldt, J.; Kil, H.; Zhang, Y.; Demajistre, R.; Wolven, B.; Meng, C.

2005-12-01

The AURORA sensor slated for flight on the NPOESS satellites represents the culmination of over 20 years of experience at JHU/APL in the design, manufacture, flight, operation and analysis of compact, cost-effective far ultraviolet sensors for space weather data collection. The far ultraviolet covers the spectral range from about 115 to 185 nm. This region is ideal for observations of the upper atmosphere because, at these wavelengths, the lower atmosphere and Earth's surface are black. AURORA will observe the mid- and low-latitude F-region ionosphere, the auroral E-region ionosphere, the day thermosphere composition, auroral energy deposition and map ionospheric irregularities. AURORA implements the flight-proven design derived from SSUSI on the DMSP Block 5D spacecraft and GUVI on the NASA TIMED spacecraft. These instruments have provided the instrument and algorithm heritage for NPOESS/AURORA. In this talk the performance capabilities of the AURORA instrument will be summarized along with the design of the instrument and algorithms. Example products will be shown for each of the measurement regimes. We acknowldge support from DMSP and NASA and the collaboration with our science colleagues at the Aerospace Corporation (Paul Straus, Jim Hecht, Dave McKenzie, and Andy Christensen) and Computational Physics (Doug Strickland, Hal Knight, and Scott Evans) and Naval Research Laboratory (Robert Meier, Mike Picone, Stefan Thonnard, Pat Dandenault, and Andy Stefan) and our colleagues at APL (Michele Weiss, Doug Holland, Bill Wood, and Jim Eichert) among others.

Vapor Transport Within the Thermal Diffusion Cloud Chamber

NASA Technical Reports Server (NTRS)

Ferguson, Frank T.; Heist, Richard H.; Nuth, Joseph A., III

2000-01-01

A review of the equations used to determine the 1-D vapor transport in the thermal diffusion cloud chamber (TDCC) is presented. These equations closely follow those of the classical Stefan tube problem in which there is transport of a volatile species through a noncondensible, carrier gas. In both cases, the very plausible assumption is made that the background gas is stagnant. Unfortunately, this assumption results in a convective flux which is inconsistent with the momentum and continuity equations for both systems. The approximation permits derivation of an analytical solution for the concentration profile in the Stefan tube, but there is no computational advantage in the case of the TDCC. Furthermore, the degree of supersaturation is a sensitive function of the concentration profile in the TD CC and the stagnant background gas approximation can make a dramatic difference in the calculated supersaturation. In this work, the equations typically used with a TDCC are compared with very general transport equations describing the 1-D diffusion of the volatile species. Whereas no pressure dependence is predicted with the typical equations, a strong pressure dependence is present with the more general equations given in this work. The predicted behavior is consistent with observations in diffusion cloud experiments. It appears that the new equations may account for much of the pressure dependence noted in TDCC experiments, but a comparison between the new equations and previously obtained experimental data are needed for verification.

Hydrodynamic theory of diffusion in two-temperature multicomponent plasmas

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

Ramshaw, J.D.; Chang, C.H.

Detailed numerical simulations of multicomponent plasmas require tractable expressions for species diffusion fluxes, which must be consistent with the given plasma current density J{sub q} to preserve local charge neutrality. The common situation in which J{sub q} = 0 is referred to as ambipolar diffusion. The use of formal kinetic theory in this context leads to results of formidable complexity. We derive simple tractable approximations for the diffusion fluxes in two-temperature multicomponent plasmas by means of a generalization of the hydrodynamical approach used by Maxwell, Stefan, Furry, and Williams. The resulting diffusion fluxes obey generalized Stefan-Maxwell equations that contain drivingmore » forces corresponding to ordinary, forced, pressure, and thermal diffusion. The ordinary diffusion fluxes are driven by gradients in pressure fractions rather than mole fractions. Simplifications due to the small electron mass are systematically exploited and lead to a general expression for the ambipolar electric field in the limit of infinite electrical conductivity. We present a self-consistent effective binary diffusion approximation for the diffusion fluxes. This approximation is well suited to numerical implementation and is currently in use in our LAVA computer code for simulating multicomponent thermal plasmas. Applications to date include a successful simulation of demixing effects in an argon-helium plasma jet, for which selected computational results are presented. Generalizations of the diffusion theory to finite electrical conductivity and nonzero magnetic field are currently in progress.« less

Stem Cell Physics. Multiple-Laser-Beam Treatment of Parkinson's Disease

NASA Astrophysics Data System (ADS)

Stefan, V.

2013-03-01

A novel method for the treatment of Parkinson's disease is proposed. Pluripotent stem cells are laser cultured, using ultrashort wavelength, (around 0.1 micron-ultraviolet radiation-with intensities of a few mW/cm2) , multiple laser beams.[2] The multiple-energy laser photons[3] interact with the neuron DNA molecules to be cloned. The laser created dopaminergic substantia nigra neurons can be, (theoretically), laser transplanted, (a higher focusing precision as compared to a syringe method), into the striatum or substantia nigra regions of the brain, or both. Supported by Nikola Tesla Labs, Stefan University.

Colloque S&T Symposium 2009: Understanding the Human Dimension in 21st Century Conflict/Warfare: Taking Care of the Front Line (comprendre la dimension humaine dans les conflits/la conduite de la guerre au xxle siecle: veiller a la ligne de front)

DTIC Science & Technology

2009-06-01

à un adversaire d’un type différent. Il a ajouté que le modèle de gestion du personnel doit également s’adapter aux changements importants que subit...humaines; on risque d’assister à un manque d’imagination et de sang- froid si nous ne nous penchons pas sur les possibilités sur le plan technologique...la conduite de la guerre au XXIe siècle: Veiller à la ligne de front Stefan Wolejszo DGMPRA Kyle Fraser DGMPRA Orrick White (Editor) DRDC Corporate

Scale/Analytical Analyses of Freezing and Convective Melting with Internal Heat Generation

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

Ali S. Siahpush; John Crepeau; Piyush Sabharwall

2013-07-01

Using a scale/analytical analysis approach, we model phase change (melting) for pure materials which generate constant internal heat generation for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. The analysis also consider constant heat flux (in a cylindrical geometry).We show the time scales in which conduction and convection heat transfer dominate.

On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: I. Cosmic microwave background radiation

NASA Astrophysics Data System (ADS)

Fisenko, Anatoliy I.; Lemberg, Vladimir

2014-07-01

Using the explicit form of the functions to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies v 1≤ v≤ v 2 are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60-600 GHz frequency interval at the temperature T=2.72548 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant σ are calculated. In the case of the dipole spectrum, the constants a and σ, and the radiative and thermodynamic properties of the CMB radiation are obtained using the mean amplitude T amp=3.358 mK. It is shown that the Doppler shift leads to a renormalization of the radiation density constant a, the Stefan-Boltzmann constant σ, and the corresponding constants for the thermodynamic functions. The expressions for new astrophysical parameters, such as the entropy density/Boltzmann constant, and number density of CMB photons are obtained. The radiative and thermodynamic properties of the Cosmic Microwave Background radiation for the monopole and dipole spectra at redshift z≈1089 are calculated.

Conceptual Commitments of AGI Systems: Editorial, Commentaries, and Response

NASA Astrophysics Data System (ADS)

2013-06-01

Editorial: Conceptual Commitments of AGI Systems Haris Dindo / James Marshall / Giovanni Pezzulo 23 General Problems of Unified Theories of Cognition, and Another Conceptual Commitment of LIDA Benjamin Angerer / Stefan Schneider 26 LIDA, Committed to Consciousness Antonio Chella 28 The Radical Interactionism Conceptual Commitment Olivier L. Georgeon / David W. Aha 31 Commitments of the Soar Cognitive Architecture John E. Laird 36 Conceptual Commitments of AGI Projects Pei Wang 39 Will (dis)Embodied LIDA Agents be Socially Interactive? Travis J. Wiltshire / Emilio J. C. Lobato / Florian G. Jentsch / Stephen M. Fiore 42 Author's Response to Commentaries Steve Strain / Stan Franklin 48

Experimental Study and a Mathematical Model of the Processes in Frozen Soil Under a Reservoir with a Hot Heat-Transfer Agent

NASA Astrophysics Data System (ADS)

Kislitsyn, A. A.; Shastunova, U. Yu.; Yanbikova, Yu. F.

2018-05-01

On an experimental setup, the authors have measured temperature fields in frozen soil during the filling of a reservoir with hot heat-transfer agent (oil), and also the change in the shape and position of the front of ice melting (isotherms T = 0°C) with time. The approximate solution of a two-dimensional Stefan problem on thawing of frozen soil has been given; it has been shown that satisfactory agreement with experimental results can only be obtained with account taken of the convective transfer of heat due to the water motion in the region of thawed soil.

Fast Ignition Thermonuclear Fusion: Enhancement of the Pellet Gain by the Colossal-Magnetic-Field Shells

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2013-10-01

The fast ignition fusion pellet gain can be enhanced by a laser generated B-field shell. The B-field shell, (similar to Earth's B-field, but with the alternating B-poles), follows the pellet compression in a frozen-in B-field regime. A properly designed laser-pellet coupling can lead to the generation of a B-field shell, (up to 100 MG), which inhibits electron thermal transport and confines the alpha-particles. In principle, a pellet gain of few-100s can be achieved in this manner. Supported in part by Nikola Tesla Labs, Stefan University, 1010 Pearl, La Jolla, CA 92038-1007.

Experimental Study and a Mathematical Model of the Processes in Frozen Soil Under a Reservoir with a Hot Heat-Transfer Agent

NASA Astrophysics Data System (ADS)

Kislitsyn, A. A.; Shastunova, U. Yu.; Yanbikova, Yu. F.

2018-03-01

On an experimental setup, the authors have measured temperature fields in frozen soil during the filling of a reservoir with hot heat-transfer agent (oil), and also the change in the shape and position of the front of ice melting (isotherms T = 0°C) with time. The approximate solution of a two-dimensional Stefan problem on thawing of frozen soil has been given; it has been shown that satisfactory agreement with experimental results can only be obtained with account taken of the convective transfer of heat due to the water motion in the region of thawed soil.

Solidification of a binary mixture

NASA Technical Reports Server (NTRS)

Antar, B. N.

1982-01-01

The time dependent concentration and temperature profiles of a finite layer of a binary mixture are investigated during solidification. The coupled time dependent Stefan problem is solved numerically using an implicit finite differencing algorithm with the method of lines. Specifically, the temporal operator is approximated via an implicit finite difference operator resulting in a coupled set of ordinary differential equations for the spatial distribution of the temperature and concentration for each time. Since the resulting differential equations set form a boundary value problem with matching conditions at an unknown spatial point, the method of invariant imbedding is used for its solution.

A bill to reauthorize and enhance Johanna's Law to increase public awareness and knowledge with respect to gynecologic cancers.

THOMAS, 111th Congress

Sen. Specter, Arlen [D-PA

2010-06-15

Senate - 06/15/2010 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Notes: For further action, see H.R.2941, which became Public Law 111-324 on 12/22/2010. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Smoothed particle hydrodynamics method for evaporating multiphase flows.

PubMed

Yang, Xiufeng; Kong, Song-Charng

2017-09-01

The smoothed particle hydrodynamics (SPH) method has been increasingly used for simulating fluid flows; however, its ability to simulate evaporating flow requires significant improvements. This paper proposes an SPH method for evaporating multiphase flows. The present SPH method can simulate the heat and mass transfers across the liquid-gas interfaces. The conservation equations of mass, momentum, and energy were reformulated based on SPH, then were used to govern the fluid flow and heat transfer in both the liquid and gas phases. The continuity equation of the vapor species was employed to simulate the vapor mass fraction in the gas phase. The vapor mass fraction at the interface was predicted by the Clausius-Clapeyron correlation. An evaporation rate was derived to predict the mass transfer from the liquid phase to the gas phase at the interface. Because of the mass transfer across the liquid-gas interface, the mass of an SPH particle was allowed to change. Alternative particle splitting and merging techniques were developed to avoid large mass difference between SPH particles of the same phase. The proposed method was tested by simulating three problems, including the Stefan problem, evaporation of a static drop, and evaporation of a drop impacting a hot surface. For the Stefan problem, the SPH results of the evaporation rate at the interface agreed well with the analytical solution. For drop evaporation, the SPH result was compared with the result predicted by a level-set method from the literature. In the case of drop impact on a hot surface, the evolution of the shape of the drop, temperature, and vapor mass fraction were predicted.

An Illustrated Overview of the Origins and Development of the QSCP Meetings

NASA Astrophysics Data System (ADS)

Maruani, Jean

The origins and development of the QSCP meetings are recalled: from a congress organized in Paris in 1986 to honour Prof. Raymond Daudel, through Franco-Bulgarian cooperation between various teams then European contracts, in the frame of COST projects, involving a network of French, Spanish, British, Italian, Swedish, and Bulgarian scientists, till the holding of the first QSCP workshop near Pisa in 1996 to honour Prof. Stefan Christov. After that there was a meeting every year, always with proceedings published. This historical overview will be presented as an illustrated journey in picturesque cities of Western and Eastern Europe, North Africa, and North America, sprinkled with historical or philosophical anecdotes and insights.

Proton Beam Fast Ignition Fusion: Synergy of Weibel and Rayleigh-Taylor Instabilities

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2011-04-01

The proton beam generation and focusing in fast ignition inertial confinement fusion is studied. The spatial and energy spread of the proton beam generated in a laser-solid interaction is increased due to the synergy of Weibel and Rayleigh-Taylor instabilities. The focal spot radius can reach 100 μm, which is nearly an order of magnitude larger than the optimal value. The energy spread decreases the beam deposition energy in the focal spot. Under these conditions, ignition of a precompressed DT fuel is achieved with the beam powers much higher than the values presently in consideration. Work supported in part by NIKOLA TESLA Laboratories (Stefan University), La Jolla, CA.

Laser-Bioplasma Interaction: Excitation and Suppression of the Brain Waves by the Multi-photon Pulsed-operated Fiber Lasers in the Ultraviolet Range of Frequencies

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander; IAPS-team Team

2017-10-01

The novel study of the laser excitation-suppression of the brain waves is proposed. It is based on the pulsed-operated multi-photon fiber-laser interaction with the brain parvalbumin (PV) neurons. The repetition frequency matches the low frequency brain waves (5-100 Hz); enabling the resonance-scanning of the wide range of the PV neurons (the generators of the brain wave activity). The tunable fiber laser frequencies are in the ultraviolet frequency range, thus enabling the monitoring of the PV neuron-DNA, within the 10s of milliseconds. In medicine, the method can be used as an ``instantaneous-on-off anesthetic.'' Supported by Nikola Tesla Labs, Stefan University.

Physics of the Brain: Interaction of the Optical-Fiber-Guided Multi-Ultraviolet-Photon Beams with the Epilepsy Topion, (the Seizure Onset Area)

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

A novel method for the possible prevention of epileptic seizures is proposed, based on the multi-ultraviolet-photon beam interaction with the epilepsy topion, (nonlinear coupling of an ultra high frequency mode to the brain beta phonons). It is hypothesized that epilepsy is a chaotic-dynamics phenomenon: small electrical changes in the epilepsy-topion lead, (within the 10s of milliseconds), to the onset of chaos, (seizure--excessive electrical discharge), and subsequent cascading into adjacent areas. The ultraviolet photons may control the imbalance of sodium and potassium ions and, consequently, may prove to be efficient in the prevention of epileptic seizures. Supported by Nikola Tesla Labs, Stefan University.

The future of electron microscopy

DOE PAGES

Zhu, Yimei; Durr, Hermann

2015-04-01

Seeing is believing. So goes the old adage and seen evidence is undoubtedly satisfying because it can be interpreted easily, though not always correctly. For centuries, humans have developed such instruments as telescopes that observe the heavens and microscopes that reveal bacteria and viruses. The 2014 Nobel Prize in Chemistry was awarded to Eric Betzig, Stefan Hell, and William Moerner for their foundational work on superresolution fluorescence microscopy in which they overcame the Abbe diffraction limit for the resolving power of conventional light microscopes. (See Physics Today, December 2014, page 18.) That breakthrough enabled discoveries in biological research and testifiesmore » to the importance of modern microscopy.« less

ms 2: A molecular simulation tool for thermodynamic properties, release 3.0

NASA Astrophysics Data System (ADS)

Rutkai, Gábor; Köster, Andreas; Guevara-Carrion, Gabriela; Janzen, Tatjana; Schappals, Michael; Glass, Colin W.; Bernreuther, Martin; Wafai, Amer; Stephan, Simon; Kohns, Maximilian; Reiser, Steffen; Deublein, Stephan; Horsch, Martin; Hasse, Hans; Vrabec, Jadran

2017-12-01

A new version release (3.0) of the molecular simulation tool ms 2 (Deublein et al., 2011; Glass et al. 2014) is presented. Version 3.0 of ms 2 features two additional ensembles, i.e. microcanonical (NVE) and isobaric-isoenthalpic (NpH), various Helmholtz energy derivatives in the NVE ensemble, thermodynamic integration as a method for calculating the chemical potential, the osmotic pressure for calculating the activity of solvents, the six Maxwell-Stefan diffusion coefficients of quaternary mixtures, statistics for sampling hydrogen bonds, smooth-particle mesh Ewald summation as well as the ability to carry out molecular dynamics runs for an arbitrary number of state points in a single program execution.

New Light on Dark Energy

NASA Astrophysics Data System (ADS)

2008-01-01

Using ESO's Very Large Telescope Interferometer, astronomers have probed the inner parts of the disc of material surrounding a young stellar object, witnessing how it gains its mass before becoming an adult. ESO PR Photo 03/08 ESO PR Photo 03a/08 The disc around MWC 147 (Artist's Impression) The astronomers had a close look at the object known as MWC 147, lying about 2,600 light years away towards the constellation of Monoceros ('the Unicorn'). MWC 147 belongs to the family of Herbig Ae/Be objects. These have a few times the mass of our Sun and are still forming, increasing in mass by swallowing material present in a surrounding disc. MWC 147 is less than half a million years old. If one associated the middle-aged, 4.6 billion year old Sun with a person in his early forties, MWC 147 would be a 1-day-old baby [1]. The morphology of the inner environment of these young stars is however a matter of debate and knowledge of it is important to better understand how stars and their cortège of planets form. The astronomers Stefan Kraus, Thomas Preibisch, and Keiichi Ohnaka have used the four 8.2-m Unit Telescopes of ESO's Very Large Telescope to this purpose, combining the light from two or three telescopes with the MIDI and AMBER instruments. "With our VLTI/MIDI and VLTI/AMBER observations of MWC147, we combine, for the first time, near- and mid-infrared interferometric observations of a Herbig Ae/Be star, providing a measurement of the disc size over a wide wavelength range [2]," said Stefan Kraus, lead-author of the paper reporting the results. "Different wavelength regimes trace different temperatures, allowing us to probe the disc's geometry on the smaller scale, but also to constrain how the temperature changes with the distance from the star." The near-infrared observations probe hot material with temperatures of up to a few thousand degrees in the innermost disc regions, while the mid-infrared observations trace cooler dust further out in the disc. The

The Growing-up of a Star

NASA Astrophysics Data System (ADS)

2008-01-01

Using ESO's Very Large Telescope Interferometer, astronomers have probed the inner parts of the disc of material surrounding a young stellar object, witnessing how it gains its mass before becoming an adult. ESO PR Photo 03/08 ESO PR Photo 03a/08 The disc around MWC 147 (Artist's Impression) The astronomers had a close look at the object known as MWC 147, lying about 2,600 light years away towards the constellation of Monoceros ('the Unicorn'). MWC 147 belongs to the family of Herbig Ae/Be objects. These have a few times the mass of our Sun and are still forming, increasing in mass by swallowing material present in a surrounding disc. MWC 147 is less than half a million years old. If one associated the middle-aged, 4.6 billion year old Sun with a person in his early forties, MWC 147 would be a 1-day-old baby [1]. The morphology of the inner environment of these young stars is however a matter of debate and knowledge of it is important to better understand how stars and their cortège of planets form. The astronomers Stefan Kraus, Thomas Preibisch, and Keiichi Ohnaka have used the four 8.2-m Unit Telescopes of ESO's Very Large Telescope to this purpose, combining the light from two or three telescopes with the MIDI and AMBER instruments. "With our VLTI/MIDI and VLTI/AMBER observations of MWC147, we combine, for the first time, near- and mid-infrared interferometric observations of a Herbig Ae/Be star, providing a measurement of the disc size over a wide wavelength range [2]," said Stefan Kraus, lead-author of the paper reporting the results. "Different wavelength regimes trace different temperatures, allowing us to probe the disc's geometry on the smaller scale, but also to constrain how the temperature changes with the distance from the star." The near-infrared observations probe hot material with temperatures of up to a few thousand degrees in the innermost disc regions, while the mid-infrared observations trace cooler dust further out in the disc. The

A unified multicomponent stress-diffusion model of drug release from non-biodegradable polymeric matrix tablets.

PubMed

Salehi, Ali; Zhao, Jin; Cabelka, Tim D; Larson, Ronald G

2016-02-28

We propose a new transport model of drug release from hydrophilic polymeric matrices, based on Stefan-Maxwell flux laws for multicomponent transport. Polymer stress is incorporated in the total mixing free energy, which contributes directly to the diffusion driving force while leading to time-dependent boundary conditions at the tablet interface. Given that hydrated matrix tablets are dense multicomponent systems, extended Stefan-Maxwell (ESM) flux laws are adopted to ensure consistency with the Onsager reciprocity principle and the Gibbs-Duhem thermodynamic constraint. The ESM flux law for any given component takes into account the friction exerted by all other species and is invariant with respect to reference velocity, thus satisfying Galilean translational invariance. Our model demonstrates that penetrant-induced plasticization of polymer chains partially or even entirely offsets the steady decline of chemical potential gradients at the tablet-medium interface that drive drug release. Utilizing a Flory-Huggins thermodynamic model, a modified form of the upper convected Maxwell constitutive equation for polymer stress and a Fujita-type dependence of mutual diffusivities on composition, depending on parameters, Fickian, anomalous or case II drug transport arises naturally from the model, which are characterized by quasi-power-law release profiles with exponents ranging from 0.5 to 1, respectively. A necessary requirement for non-Fickian release in our model is that the matrix stress relaxation time is comparable to the time scale for water diffusion. Mutual diffusivities and their composition dependence are the most decisive factors in controlling drug release characteristics in our model. Regression of the experimental polymer dissolution and drug release profiles in a system of Theophylline/cellulose (K15M) demonstrate that API-water mutual diffusivity in the presence of excipient cannot generally be taken as a constant. Copyright © 2016 Elsevier B.V. All

Global upper ocean heat storage response to radiative forcing from changing solar irradiance and increasing greenhouse gas/aerosol concentrations

NASA Astrophysics Data System (ADS)

White, Warren B.; Cayan, Daniel R.; Lean, Judith

1998-09-01

We constructed gridded fields of diabatic heat storage changes in the upper ocean from 20°S to 60°N from historical temperature profiles collected from 1955 to 1996. We filtered these 42 year records for periods of 8 to 15 years and 15 to 30 years, producing depth-weighted vertical average temperature (DVT) changes from the sea surface to the top of the main pycnocline. Basin and global averages of these DVT changes reveal decadal and interdecadal variability in phase across the Indian, Pacific, Atlantic, and Global Oceans, each significantly correlated with changing surface solar radiative forcing at a lag of 0+/-2 years. Decadal and interdecadal changes in global average DVT are 0.06°+/-0.01°K and 0.04°K+/-0.01°K, respectively, the same as those expected from consideration of the Stefan-Boltzmann radiation balance (i.e., 0.3°K per Wm-2) in response to 0.1% changes in surface solar radiative forcing of 0.2 Wm-2 and 0.15 Wm-2, respectively. Global spatial patterns of DVT changes are similar to temperature changes simulated in coupled ocean-atmosphere models, suggesting that natural modes of Earth's variability are phase-locked to the solar irradiance cycle. A trend in global average DVT of 0.15°K over this 42 year record cannot be explained by changing surface solar radiative forcing. But when we consider the 0.5 Wm-2 increase in surface radiative forcing estimated from the increase in atmospheric greenhouse gas and aerosol (GGA) concentrations over this period [Intergovernmental Panel on Climate Change, 1995], the Stefan-Boltzmann radiation balance yields this observed change. Moreover, the sum of solar and GGA surface radiative forcing can explain the relatively sharp increase in global and basin average DVT in the late 1970's.

Steady-State Diffusion of Water through Soft-Contact LensMaterials

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

Fornasiero, Francesco; Krull, Florian; Radke, Clayton J.

2005-01-31

Water transport through soft contact lenses (SCL) is important for acceptable performance on the human eye. Chemical-potential gradient-driven diffusion rates of water through soft-contact-lens materials are measured with an evaporation-cell technique. Water is evaporated from the bottom surface of a lens membrane by impinging air at controlled flow rate and humidity. The resulting weight loss of a water reservoir covering the top surface of the contact-lens material is recorded as a function of time. New results are reported for a conventional hydrogel material (SofLens{trademark} One Day, hilafilcon A, water content at saturation W{sub 10} = 70 weight %) and amore » silicone hydrogel material (PureVision{trademark}, balafilcon A, W{sub 10} = 36 %), with and without surface oxygen plasma treatment. Also, previously reported data for a conventional HEMA-SCL (W{sub 10} = 38 %) hydrogel are reexamined and compared with those for SofLens{trademark} One Day and PureVision{trademark} hydrogels. Measured steady-state water fluxes are largest for SofLens{trademark} One Day, followed by PureVision{trademark} and HEMA. In some cases, the measured steady-state water fluxes increase with rising relative air humidity. This increase, due to an apparent mass-transfer resistance at the surface (trapping skinning), is associated with formation of a glassy skin at the air/membrane interface when the relative humidity is below 55-75%. Steady-state water-fluxes are interpreted through an extended Maxwell-Stefan diffusion model for a mixture of species starkly different in size. Thermodynamic nonideality is considered through Flory-Rehner polymer-solution theory. Shrinking/swelling is self-consistently modeled by conservation of the total polymer mass. Fitted Maxwell-Stefan diffusivities increase significantly with water concentration in the contact lens.« less

Predicting the Kinetics of Ice Recrystallization in Aqueous Sugar Solutions

PubMed Central

2018-01-01

The quality of stored frozen products such as foods and biomaterials generally degrades in time due to the growth of large ice crystals by recrystallization. While there is ample experimental evidence that recrystallization within such products (or model systems thereof) is often dominated by diffusion-limited Ostwald ripening, the application of Ostwald-ripening theories to predict measured recrystallization rates has only met with limited success. For a model system of polycrystalline ice within an aqueous solution of sugars, we here show recrystallization rates can be predicted on the basis of Ostwald ripening theory, provided (1) the theory accounts for the fact the solution can be nonideal, nondilute and of different density than the crystals, (2) the effect of ice-phase volume fraction on the diffusional flux of water between crystals is accurately described, and (3) all relevant material properties (involving binary Fick diffusion coefficients, the thermodynamic factor of the solution, and the surface energy of ice) are carefully estimated. To enable calculation of material properties, we derive an alternative formulation of Ostwald ripening in terms of the Maxwell–Stefan instead of the Fick approach to diffusion. First, this leads to a cancellation of the thermodynamic factor (a measure for the nonideality of a solution), which is a notoriously difficult property to obtain. Second, we show that Maxwell–Stefan diffusion coefficients can to a reasonable approximation be related to self-diffusion coefficients, which are relatively easy to measure or predict in comparison to Fick diffusion coefficients. Our approach is validated for a binary system of water and sucrose, for which we show predicted recrystallization rates of ice compare well to experimental results, with relative deviations of at most a factor of 2. PMID:29651228

Predicting the Kinetics of Ice Recrystallization in Aqueous Sugar Solutions.

PubMed

van Westen, Thijs; Groot, Robert D

2018-04-04

The quality of stored frozen products such as foods and biomaterials generally degrades in time due to the growth of large ice crystals by recrystallization. While there is ample experimental evidence that recrystallization within such products (or model systems thereof) is often dominated by diffusion-limited Ostwald ripening, the application of Ostwald-ripening theories to predict measured recrystallization rates has only met with limited success. For a model system of polycrystalline ice within an aqueous solution of sugars, we here show recrystallization rates can be predicted on the basis of Ostwald ripening theory, provided (1) the theory accounts for the fact the solution can be nonideal, nondilute and of different density than the crystals, (2) the effect of ice-phase volume fraction on the diffusional flux of water between crystals is accurately described, and (3) all relevant material properties (involving binary Fick diffusion coefficients, the thermodynamic factor of the solution, and the surface energy of ice) are carefully estimated. To enable calculation of material properties, we derive an alternative formulation of Ostwald ripening in terms of the Maxwell-Stefan instead of the Fick approach to diffusion. First, this leads to a cancellation of the thermodynamic factor (a measure for the nonideality of a solution), which is a notoriously difficult property to obtain. Second, we show that Maxwell-Stefan diffusion coefficients can to a reasonable approximation be related to self-diffusion coefficients, which are relatively easy to measure or predict in comparison to Fick diffusion coefficients. Our approach is validated for a binary system of water and sucrose, for which we show predicted recrystallization rates of ice compare well to experimental results, with relative deviations of at most a factor of 2.

[Between the European past and the American future: two papers about Brazil in the 1930s].

PubMed

Lisboa, Karen Macknow

2014-01-01

The article examines the idea of Europe conceived by Stefan Zweig and Hermann Ullmann in the similarly titled books about Brazil written in the late 1930s and early 1940s. In the political context between the great wars marked by the rise of Nazism, the question is posed regarding to what extent Europe continues to serve as a model of civilization and what the critical dimension is that is expressed in concepts reversing the roles of Europe and Brazil. One detects a partial rupture with dichotomous and hierarchical viewpoints about the relationship between the Old World and the New World, and new forms of relationship between these regions within the worldwide context are suggested.

ITER Plasma at Ion Cyclotron Frequency Domain: The Fusion Alpha Particles Diagnostics Based on the Stimulated Raman Scattering of Fast Magnetosonic Wave off High Harmonic Ion Bernstein Modes

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2014-10-01

A novel method for alpha particle diagnostics is proposed. The theory of stimulated Raman scattering, SRS, of the fast wave and ion Bernstein mode, IBM, turbulence in multi-ion species plasmas, (Stefan University Press, La Jolla, CA, 2008). is utilized for the diagnostics of fast ions, (4)He (+2), in ITER plasmas. Nonlinear Landau damping of the IBM on fast ions near the plasma edge leads to the space-time changes in the turbulence level, (inverse alpha particle channeling). The space-time monitoring of the IBM turbulence via the SRS techniques may prove efficient for the real time study of the fast ion velocity distribution function, spatial distribution, and transport. Supported by Nikola Tesla Labs., La Jolla, CA 92037.

Efficient numerical simulation of an electrothermal de-icer pad

NASA Technical Reports Server (NTRS)

Roelke, R. J.; Keith, T. G., Jr.; De Witt, K. J.; Wright, W. B.

1987-01-01

In this paper, a new approach to calculate the transient thermal behavior of an iced electrothermal de-icer pad was developed. The method of splines was used to obtain the temperature distribution within the layered pad. Splines were used in order to create a tridiagonal system of equations that could be directly solved by Gauss elimination. The Stefan problem was solved using the enthalpy method along with a recent implicit technique. Only one to three iterations were needed to locate the melt front during any time step. Computational times were shown to be greatly reduced over those of an existing one dimensional procedure without any reduction in accuracy; the curent technique was more than 10 times faster.

Comparison of radon doses based on different radon monitoring approaches.

PubMed

Vaupotič, Janja; Smrekar, Nataša; Žunić, Zora S

2017-04-01

In 43 places (23 schools, 3 kindergartens, 16 offices and one dwelling), indoor radon has been monitored as an intercomparison experiment, using α-scintillation cells (SC - Jožef Stefan Institute, Slovenia), various kinds of solid state nuclear track detectors (KfK - Karlsruhe Institute of Technology, Germany; UFO - National Institute of Radiological Sciences, Chiba, Japan; RET - University College Dublin, Ireland) and active electronic devices (EQF, Sarad, Germany). At the same place, the radon levels and, consequently, the effective doses obtained with different radon devices differed substantially (by a factor of 2 or more), and no regularity was observed as regards which detector would show a higher or lower dose. Copyright © 2016 Elsevier Ltd. All rights reserved.

Single molecules, cells, and super-resolution optics (Presentation Video)

NASA Astrophysics Data System (ADS)

Betzig, Eric

2015-03-01

In this plenary presentation, Eric Betzig talks about his scientific journey that led to the Nobel Prize. He made waves early in his career by helping to develop a technique known as near-field microscopy, which brought into focus structures that scientists had long considered too small to see with a light microscope. Eric Betzig is a group leader at Janelia Research Campus of the Howard Hughes Medical Institute (HHMI) in Ashburn, VA. He recieved a BS in physics from California Institute of Technology and a PhD in applied and engineering physics from Cornell University. Betzig received the 2014 Nobel Prize in Chemistry, along with William Moerner and Stefan Hell, for their development of super-resolved fluorescence microscopy.

Adult Patients' Experiences of Nursing Care Dependence.

PubMed

Piredda, Michela; Matarese, Maria; Mastroianni, Chiara; D'Angelo, Daniela; Hammer, Marilyn J; De Marinis, Maria Grazia

2015-09-01

Care dependence can be associated with suffering and humiliation. Nurses' awareness of patients' perception of care dependence is crucial to enable them in helping the dependent persons. This study aimed to describe adult patients' experience of nursing care dependence. A metasynthesis was conducted to integrate qualitative findings from 18 studies published through December 2014 on adult patients' experiences of care dependency. Procedures included the Johanna Briggs Institute approach for data extraction, quality appraisal, and integration of findings. The experience of dependence revealed the concept of the embodied person, particularly in relation to care of the physical body. The relationship between the individual and nurses within the context of care had a major impact for dependent patients. When the care relation was perceived as positive, the experience led to the development of the person in finding new balances in life, but when it was perceived as negative, it increased patient' suffering. Care dependence is manifested mostly as bodily dependence and is consistent with its relational nature. The nurse-patient relationship is important to the dependent patients' experience. A greater understanding of patients' experiences of dependence is crucial to enable nurses in improving care and decreasing patient suffering. © 2015 Sigma Theta Tau International.

Multicomponent lattice Boltzmann model from continuum kinetic theory.

PubMed

Shan, Xiaowen

2010-04-01

We derive from the continuum kinetic theory a multicomponent lattice Boltzmann model with intermolecular interaction. The resulting model is found to be consistent with the model previously derived from a lattice-gas cellular automaton [X. Shan and H. Chen, Phys. Rev. E 47, 1815 (1993)] but applies in a much broader domain. A number of important insights are gained from the kinetic theory perspective. First, it is shown that even in the isothermal case, the energy equipartition principle dictates the form of the equilibrium distribution function. Second, thermal diffusion is shown to exist and the corresponding diffusivities are given in terms of macroscopic parameters. Third, the ordinary diffusion is shown to satisfy the Maxwell-Stefan equation at the ideal-gas limit.

The Triangulum

NASA Image and Video Library

2011-01-10

NASA image release January 10, 2011 The Triangulum, located nearly 3 million light years from Earth, is another far galaxy where researchers have found diffuse interstellar bands (DIBs). The detailed observations needed to see DIBs along a straight line from Earth to an individual star in such a distant galaxy stretch the limits of even the largest telescopes. Credit: NASA/Swift Science Team/Stefan Immler To read more go to: www.nasa.gov/topics/universe/features/molecule-fingerprin... NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

[PREHISTORY IN THE WORK AND WRITINGS OF KAROL LIBELT].

PubMed

Linetty, Jakub

2015-01-01

Prehistoric archaeology constituted an important topic in the writings of Karol Libelt during the final stage of his work. As a result of several years' research and bringing up this subject in his texts, Libelt made notable achievements in the field of prehistoric archaeology. The most important of them are: description of archaeological discoveries in Czeszewo, participation in a dispute over prehistoric chronology with Stefan Pawlicki in 1871, and also one of the first descriptions of the Stone Age in the Polish literature. Thus Libelt should be considered as a pioneer in prehistoric research, particularly the Stone Age, in Poland. Apart from that, among his undoubted achievements was propagation of the theory of evolution, although with reservations, during the earliest stage of Darwinism's reception in Poland.

Characterization of gamma field in the JSI TRIGA reactor

NASA Astrophysics Data System (ADS)

Ambrožič, Klemen; Radulović, Vladimir; Snoj, Luka; Gruel, Adrien; Guillou, Mael Le; Blaise, Patrick; Destouches, Christophe; Barbot, Loïc

2018-01-01

Research reactors such as the "Jožzef Stefan" Institute TRIGA reactor have primarily been designed for experimentation and sample irradiation with neutrons. However recent developments in incorporating additional instrumentation for nuclear power plant support and with novel high flux material testing reactor designs, γ field characterization has become of great interest for the characterization of the changes in operational parameters of electronic devices and for the evaluation of γ heating of MTR's structural materials in a representative reactor Γ spectrum. In this paper, we present ongoing work on γ field characterization both experimentally, by performing γ field measurements, and by simulations, using Monte Carlo particle transport codes in conjunction with R2S methodology for delayed γ field characterization.

History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience.

PubMed

Baldani, José I; Baldani, Vera L D

2005-09-01

This review covers the history on Biological Nitrogen Fixation (BNF) in Graminaceous plants grown in Brazil, and describes research progress made over the last 40 years, most of which was coordinated by Johanna Döbereiner. One notable accomplishment during this period was the discovery of several nitrogen-fixing bacteria such as the rhizospheric (Beijerinckia fluminensis and Azotobacter paspali), associative (Azospirillum lipoferum, A. brasilense, A. amazonense) and the endophytic (Herbaspirillum seropedicae, H. rubrisubalbicans, Gluconacetobacter diazotrophicus, Burkholderia brasilensis and B. tropica). The role of these diazotrophs in association with grasses, mainly with cereal plants, has been studied and a lot of progress has been achieved in the ecological, physiological, biochemical, and genetic aspects. The mechanisms of colonization and infection of the plant tissues are better understood, and the BNF contribution to the soil/plant system has been determined. Inoculation studies with diazotrophs showed that endophytic bacteria have a much higher BNF contribution potential than associative diazotrophs. In addition, it was found that the plant genotype influences the plant/bacteria association. Recent data suggest that more studies should be conducted on the endophytic association to strengthen the BNF potential. The ongoing genome sequencing programs: RIOGENE (Gluconacetobacter diazotrophicus) and GENOPAR (Herbaspirillum seropedicae) reflect the commitment to the BNF study in Brazil and should allow the country to continue in the forefront of research related to the BNF process in Graminaceous plants.

Energetic cost of ichthyophonus infection in Juvenile Pacific Herring (Clupea pallasii)

USGS Publications Warehouse

Vollenweider, Johanna J.; Gregg, J.L.; Heintz, R.A.; Hershberger, P.K.

2011-01-01

The energetic costs of fasting and Ichthyophonus infection were measured in juvenile Pacific herring (Clupea pallasii) in a lab setting at three temperatures. Infected herring incurred significant energetic costs, the magnitude of which depended on fish condition at the time of infection (fat versus lean). Herring that were fed continually and were in relatively good condition at the time of infection (fat) never stored lipid despite ad libitum feeding. In feeding herring, the energetic cost of infection was a 30 reduction in total energy content relative to controls 52 days post infection. Following food deprivation (lean condition), infection caused an initial delay in the compensatory response of herring. Thirty-one days after re-feeding, the energetic cost of infection in previously-fasted fish was a 32 reduction in total energy content relative to controls. Body composition of infected herring subsequently recovered to some degree, though infected herring never attained the same energy content as their continuously fed counterparts. Fifty-two days after re-feeding, the energetic cost of infection in previously-fasted fish was a 6 reduction in total energy content relative to controls. The greatest impacts of infection occurred in colder temperatures, suggesting Ichthyophonus-induced reductions in body condition may have greater consequences in the northern extent of herring's range, where juveniles use most of their energy reserves to survive their first winter. Copyright ?? 2011 Johanna J. Vollenweider et al.

PREFACE: Seventh International Conference on Dissociative Recombination: Theory, Experiments and Applications

NASA Astrophysics Data System (ADS)

van der Zande, Wim J.

2009-09-01

possible by generous sponsors, whom we thank wholeheartedly: The Radboud University Nijmegen, The Institute for Molecules and Materials of the Radboud University Nijmegen, The Foundation for Fundamental Research on Matter (Stichting FOM), The Foundation PHYSICA (Stichting Physica), and The Netherlands Royal Academy of Sciences (KNAW). The organisational support by Erna Gouwens van Oss before and during the conference was essential for its success. The help of Thanja Lambrechts and Vitali Zhaunerchyk during the preparation of the proceedings is greatly appreciated. The delay in the publication of these proceedings is entirely caused by the editor. The authors of the contributions are thanked for the quality of their contributions, Wim J van der Zande, Editor Institute for Molecules and Materials, Radboud University Nijmegen, PO Box 9010, NL-6500 GL Nijmegen, The Netherlands Email: w.vanderzande@science.ru.nl Conference photograph Participants of the 7th International Conference on Dissociative Recombination: Theory, Experiments and Applications, taken in front of d'Amelander Kaap, the conference venue in Ameland, one of the Wadden Islands in the North of the Netherlands. 1. Dror Shafir21. Annemieke Petrignani41. Oumanou Motopan 2. Ioan Scheider22. Johanna Roos42. Max Berg 3. Nigel Adams23. Erna Gouwens van Oss43. Henrik Buhr 4. Hajime Tanuma24. Natalie de Ruette44. Ilya Fabrikant 5. Jonathan Tennyson25. Francois Wameu Tamo45. Claude Krantz 6. Vitali Zhaunerchyk26. Rainer Johnsen46. Michael Stenrup 7. Robert Continetti27. Viatcheslav Kokoouline47. Xavier Urbain 8. Stefan Rosén28. Hidekazu Takagi48. Evelyne Roueff 9. Erik Vigren29. Hans-Jakob Wörner49. Dirk Schwalm 10. Magdalena Kaminska30. Oskar Asvany50. Valery Ngassam 11. Chris Greene31. Lutz Lammich51. Julien Lecointre 12. Steffen Novotny32. Brandon Jordon-Thaden52. Ann Orel 13. Amy Schumak33. Wolf Diettrich Geppert53. Ihor Korolov 14. Gerard van Rooij34. Alexander Faure54. Romain Guerot 15. Wim van der Zande35. Mathias

The Spectrum of Thermally Stimulated Surface Plasmon Polaritons of a Linear Sample

NASA Astrophysics Data System (ADS)

Gerasimov, V. V.; Nikitin, A. K.; Khasanov, I. Sh.; Trang, Ta Thu

2017-12-01

An analytical model of the spectrum of thermally stimulated surface plasmon polaritons (TSSPPs) coming to the edge of a linear conducting sample has been developed. It has been found that the spectrum of such TSSPPs obeys neither the Wien law nor the Stefan-Boltzmann law for thermal radiation. The maximum of this spectrum is shifted to the low-frequency region with respect to the spectrum of the absolutely black body, and the magnitude of the shift is proportional to the sample length. The plasmon nature of the intensity increment of thermal radiation from the edge of a plane face of a duralumin sample has been verified experimentally. It has been shown that the intensity and spectrum of this increment can be controlled both by the sample temperature and by the extension of the face.

[Death cause of Józef Hempel, M.D. - truth or myth?].

PubMed

Witczak, Włodzimierz

2004-01-01

In this article the author makes an attempt to explain causes of untimely death of Józef Hempel, a Cracow physician. In the Polish historiography there has been a strong belief that he was a victim of an unfortunate experiment with tuberculin administered to him by Robert Koch in Berlin in 1890. However, there was every indication that his death was caused by purulent appendicitis with complicated peritonitis. Memoirs of Stefan Dunin, a journalist, were the most probable source of this misinformation on the tuberculin experiment. The author emphasizes that hte memoirs should not be used in works on history of the Polish phthisiology. He draws our attention to dangers that were related to attempts of treating tuberculosis with tuberculin and also gives basic biographical information about Hempel.

Diffusion of Charged Species in Liquids

NASA Astrophysics Data System (ADS)

Del Río, J. A.; Whitaker, S.

2016-11-01

In this study the laws of mechanics for multi-component systems are used to develop a theory for the diffusion of ions in the presence of an electrostatic field. The analysis begins with the governing equation for the species velocity and it leads to the governing equation for the species diffusion velocity. Simplification of this latter result provides a momentum equation containing three dominant forces: (a) the gradient of the partial pressure, (b) the electrostatic force, and (c) the diffusive drag force that is a central feature of the Maxwell-Stefan equations. For ideal gas mixtures we derive the classic Nernst-Planck equation. For liquid-phase diffusion we encounter a situation in which the Nernst-Planck contribution to diffusion differs by several orders of magnitude from that obtained for ideal gases.

Diffusion of Charged Species in Liquids.

PubMed

Del Río, J A; Whitaker, S

2016-11-04

In this study the laws of mechanics for multi-component systems are used to develop a theory for the diffusion of ions in the presence of an electrostatic field. The analysis begins with the governing equation for the species velocity and it leads to the governing equation for the species diffusion velocity. Simplification of this latter result provides a momentum equation containing three dominant forces: (a) the gradient of the partial pressure, (b) the electrostatic force, and (c) the diffusive drag force that is a central feature of the Maxwell-Stefan equations. For ideal gas mixtures we derive the classic Nernst-Planck equation. For liquid-phase diffusion we encounter a situation in which the Nernst-Planck contribution to diffusion differs by several orders of magnitude from that obtained for ideal gases.

Diffusion of Charged Species in Liquids

PubMed Central

del Río, J. A.; Whitaker, S.

2016-01-01

In this study the laws of mechanics for multi-component systems are used to develop a theory for the diffusion of ions in the presence of an electrostatic field. The analysis begins with the governing equation for the species velocity and it leads to the governing equation for the species diffusion velocity. Simplification of this latter result provides a momentum equation containing three dominant forces: (a) the gradient of the partial pressure, (b) the electrostatic force, and (c) the diffusive drag force that is a central feature of the Maxwell-Stefan equations. For ideal gas mixtures we derive the classic Nernst-Planck equation. For liquid-phase diffusion we encounter a situation in which the Nernst-Planck contribution to diffusion differs by several orders of magnitude from that obtained for ideal gases. PMID:27811959

History and status of embryology and developmental biology at Polish Medical Faculties and Schools.

PubMed

Bartel, Hieronim

2008-01-01

In Poland, medical embryology (both scientific research and teaching of the subject) has traditionally involved Chairs of Histology and Embryology rather than Obstetrics and Gynecology. Before World War II, the most buoyant centers for embryological research among the five universities at the time (in Warsaw, Krakow, Poznan, Lvov and Vilnius), were the Chairs of Embryology and Histology at Medical Faculties of the Jagiellonian University in Krakow and the University of Vilnius. After World War II, eleven Medical Academies (Universities of Medicine) came into being (Warsaw, Krakow, Poznan, Lodz, Gdansk, Bialystok, Bydgoszcz, Szczecin, Wroclaw, Katowice and Lublin). They conduct scientific research on normal development of the human embryo as well as teratology studies. In the XX century, eminent medicine-related embryologist included professors Emil Godlewski Jr., Stanislaw Hiller and Stefan Baginski.

Numerical analysis of fluid flow and heat transfer during melting inside a cylindrical container for thermal energy storage system

NASA Astrophysics Data System (ADS)

Bellan, Selvan; Cheok, Cho Hyun; Gokon, Nobuyuki; Matsubara, Koji; Kodama, Tatsuya

2017-06-01

This paper presents a numerical analysis of unconstrained melting of high temperature(>1000K) phase change material (PCM) inside a cylindrical container. Sodium chloride and Silicon carbide have been used as phase change material and shell of the capsule respectively. The control volume discretization approach has been used to solve the conservation equations of mass, momentum and energy. The enthalpy-porosity method has been used to track the solid-liquid interface of the PCM during melting process. Transient numerical simulations have been performed in order to study the influence of radius of the capsule and the Stefan number on the heat transfer rate. The simulation results show that the counter-clockwise Buoyancy driven convection over the top part of the solid PCM enhances the melting rate quite faster than the bottom part.

Use of boron nitride for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements

NASA Astrophysics Data System (ADS)

Radulović, Vladimir; Trkov, Andrej; Jaćimović, Radojko; Gregoire, Gilles; Destouches, Christophe

2016-12-01

A recent experimental irradiation and measurement campaign using containers made from boron nitride (BN) at the Jožef Stefan Institute (JSI) TRIGA Mark II reactor in Ljubljana, Slovenia, has shown the applicability of BN for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements. The first part of the paper focuses on the determination of the transmission function of a BN container through Monte Carlo calculations and experimental measurements. The second part presents the process of tayloring the sensitivity of integral activation measurements to specific needs and a selection of suitable radiative capture reactions for neutron spectrum characterization in the epithermal range. A BN container used in our experiments and its qualitative effect on the neutron spectrum in the irradiation position employed is displayed in the Graphical abstract.

“The Marshall Rosenbluth International Summer School – 2007: Plasma Thermonuclear Fusion and Plasma Astrophysics – 2007”

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

Stefan, Vladislav Alexander

Contents: H. Berk: Frequency Sweeping Due to Phase Space Structure Formation in Plasmas M. Campbell : The Legacy of Marshall Rosenbluth in the Development of the Laser Fusion Program in the United States J. Candy: Gyrokinetic Simulations of Fusion Plasmas P. Diamond: The Legacy of Marshall Rosenbluth in Magnetic Confinement Theory G-Y. Fu: Nonlinear Hybrid Simulations of Multiple Energetic Particle Driven Alfven Modes in Toroidal Plasmas O. Gurcan: Theory of Intrinsic Rotation and Momentum Transport V. L. Jacobs: Kinetic and Spectral Descriptions for Atomic Processes in Astrophysical and Laboratory Plasmas C. F. Kennel: Marshall Rosenbluth and Roald Sagdeev in Trieste:Themore » Birth of Modern Space Plasma N. A. Krall: The Contribution of Marshall Rosenbluth in the Development of Plasma Drift Wave and Universal Instability Theories C. S. Liu: The Legacy of Marshall Rosenbluth in Laser-Plasma Interaction Research N. Rostoker: Plasma Physics Research With Marshall Rosenbluth - My Teacher R. Z. Sagdeev: The Legacy of Marshall Rosenbluth in Plasma Physics V. Alexander Stefan A Note on the Rosenbluth Paper: Phys. Rev. Letters, 29, 565 (1972), and the Research in Parametric Plasma Theory Thereupon J. W. Van Dam: The Role of Marshall Rosenbluth in the Development of the Thermonuclear Fusion Program in the U.S.A. E. P. Velikhov: Problems in Plasma Astrophysics R. White: The Role of Marshall Rosenbluth in the Development of the Particle and MHD Interaction in Plasmas X. Xu: Edge Gyrokinetic Theory and Continuum Simulations Marshall Nicholas ROSENBLUTH (A Brief Biography) b. February 5,1927 - Albany, New York. d. September 28, 2003 - San Diego, California. M. N. Rosenbluth, a world-acclaimed scientist, is one of the ultimate authorities in plasma and thermonuclear fusion research, often indicated by the sobriquet the "Pope of Plasma Physics." His theoretical contributions have been central to the development of controlled thermonuclear fusion. In the 1950s his pioneering

Radiation-thermometric study of isolated hot molten metal spheres by containerless and contactless measurement techniques

NASA Astrophysics Data System (ADS)

Lee, G. W.; Jeon, S.; Park, C.; Kang, D. H.; Choi, B. I.; Park, S. N.

2013-09-01

An electrostatic levitation (ESL) device is developed to study the radiation-properties of liquid metals at high temperature. The technique provides good advantage, such as fast response of temperature change on a sample, clear features of recalescence and plateau during freezing, no contamination or no reaction with environment, easy control of supercooling deducing hypercooling limit, and relatively simple analysis of thermodynamic quantities because of only radiative cooling process under vacuum. In this study, we could obtain a hypercooling limit (i.e., maximum supercooling) of liquid Ti, 341 K using the ESL. An accurate ratio of the specific heat to total hemispherical emissivity of liquid Ti was obtained by Stefan-Boltzmann law. Then, the specific heat and total hemispherical emissivity of Ti liquid metal can be estimated with the hypercooling limit and known fusion enthalpy values of Ti, which has been rarely reported.

Liquid helium-free cryostat and hermetically sealed cryogenic microwave cavity for hyperfine spectroscopy of antiprotonic helium

PubMed Central

Massiczek, O.; Friedreich, S.; Juhász, B.; Widmann, E.; Zmeskal, J.

2011-01-01

The design and properties of a new cryogenic set-up for laser–microwave–laser hyperfine structure spectroscopy of antiprotonic helium – an experiment performed at the CERN-Antiproton Decelerator (AD), Geneva, Switzerland – are described. Similar experiments for 4He have been performed at the AD for several years. Due to the usage of a liquid helium operated cryostat and therefore necessary refilling of coolants, a loss of up to 10% beamtime occurred. The decision was made to change the cooling system to a closed-circuit cryocooler. New hermetically sealed target cells with minimised 3He gas volume and different dimensions of the microwave resonator for measuring the 3He transitions were needed. A new set-up has been designed and tested at Stefan Meyer Institute in Vienna before being used for the 2009 and 2010 beamtimes at the AD. PMID:22267883

Physics of the Brain. Prevention of the Epileptic Seizures by the Multi-photon Pulsed-operated Fiber Lasers in the Ultraviolet Range of Frequencies.

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander; IAPS Team

The novel study of the epileptogenesis mechanisms is proposed. It is based on the pulsed-operated (amplitude modulation) multi-photon (frequency modulation) fiber-laser interaction with the brain epilepsy-topion (the epilepsy onset area), so as to prevent the excessive electrical discharge (epileptic seizure) in the brain. The repetition frequency, Ω, matches the low frequency (epileptic) phonon waves in the brain. The laser repetition frequency (5-100 pulses per second) enables the resonance-scanning of the wide range of the phonon (possible epileptic-to-be) activity in the brain. The tunable fiber laser frequencies, Δω (multi photon operation), are in the ultraviolet frequency range, thus enabling monitoring of the electrical charge imbalance (within the 10s of milliseconds), and the DNA-corruption in the epilepsy-topion, as the possible cause of the disease. Supported by Nikola Tesla Labs., Stefan University.

Modeling Ignition of HMX with the Gibbs Formulation

NASA Astrophysics Data System (ADS)

Lee, Kibaek; Stewart, D. Scott

2017-06-01

We present a HMX model with the Gibbs formulation in which stress tensor and temperature are assumed to be in local equilibrium, but phase/chemical changes are not assumed to be in equilibrium. We assume multi-components for HMX including beta- and delta-phase, liquid, and gas phase of HMX and its gas products. Isotropic small strain solid model, modified Fried Howard liquid EOS, and ideal gas EOS are used for its relevant component. Phase/chemical changes are characterized as reactions and are in individual reaction rate. Maxwell-Stefan model is used for diffusion. Excited gas products in the local domain lead unreacted HMX solid to the ignition event. Density of the mixture, stress, strain, displacement, mass fractions, and temperature are considered in 1D domain with time histories. Office of Naval Research and Air Force Office of Scientific Research.

Commentary on Muscle dysmorphia as an addiction: a response to Grant (2015) and Nieuwoudt (2015).

PubMed

Griffiths, Mark D; Foster, Andrew C; Shorter, Gillian W

2015-03-01

Following the publication of our paper ‘Muscle Dysmorphia: Could it be classified as an addiction to body image?’ in the Journal of Behavioral Addictions, two commentaries by Jon Grant and Johanna Nieuwoudt were published in response to our paper. Using the ‘addiction components model’, our main contention is that muscle dysmorphia (MD) actually comprises a number of different actions and behaviors and that the actual addictive activity is the maintaining of body image via a number of different activities such as bodybuilding, exercise, eating certain foods, taking specific drugs (e.g., anabolic steroids), shopping for certain foods, food supplements, and purchase or use of physical exercise accessories. This paper briefly responds to these two commentaries. While our hypothesized specifics relating to each addiction component sometimes lack empirical support (as noted explicitly by both Nieuwoudt and Grant), we still believe that our main thesis (that almost all the thoughts and behaviors of those with MD revolve around the maintenance of body image) is something that could be empirically tested in future research by those who already work in the area. We hope that the ‘Addiction to Body Image’ model we proposed provides a new framework for carrying out work in both empirical and clinical settings. The idea that MD could potentially be classed as an addiction cannot be negated on theoretical grounds as many people in the addiction field are turning their attention to research in new areas of behavioral addiction.

Flood risk assessment of potential casualties in a global scale

NASA Astrophysics Data System (ADS)

Diaz Loaiza, Andres; Englhardt, Johanna; Boekhorst, Ellen; Ward, Philip; Aerts, Jeroen

2017-04-01

Flood risk assessment of potential casualties in a global scale. M. Andres Diaz-Loaiza (1), Johanna Englhardt (1), Ellen de Boekhorst (1), Philip J. Ward (1) and Jeroen Aerts (1) (1) Institute for Environmental Studies, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands. andres.diazloaiza@vu.nl Floods are one of the most dangerous natural disasters for humanity, affecting many people every year. Quantitative risk models on a global scale are nowadays available tools for institutions and actors in charge of risk management in order to plan possible mitigation measures in case of flood risk events. Many of these models have been focus on potential economic damage, population and GDP exposure, but the potential casualties assessment has been left aside. This is partially due to the complexity of the problem itself, in which several variables like the age of a pedestrian (drag/exposed to a flood event), or his weight and swimming experience can be decisive for the complete understanding of the problem. In the present work is presented the advances for the development of a methodology in order to include in the GLOFRIS model a new indicator in case of flood risk events. Preliminary analysis relating the GDP with the potential casualties shows that undeveloped countries have more susceptibility to loss of life in case of flood events. This because the GDP indicator evidences as well the protection measures available in a country.

COMMITTEES: Quark Matter 2008 Organising and International Advisory Committees

NASA Astrophysics Data System (ADS)

2008-10-01

Organising Committee Madan M Aggarwal (Chandigarh) Jan-e Alam (Kolkata) Convener Arup Bandyopadhyay (Kolkata) Debades Bandyopadhyay (Kolkata) Rahul Basu (Chennai) Rakesh K Bhandari (Kolkata) Anju Bhasin (Jammu) Subhasis Chattopadhyay (Kolkata) Convener Sukalyan Chattopadhyay (Kolkata) Asis Chaudhuri (Kolkata) Premomoy Ghosh (Kolkata) Sanjay Ghosh (Kolkata) Sourendu Gupta (Mumbai) Muhammad Irfan (Aligarh) Durga P Mahapatra (Bhubaneswar) DAmruta Mishra (New Delhi) Ajit K Mohanty (Mumbai) Bedangadas Mohanty (Kolkata) Vaisali Naik (Kolkata) Tapan K Nayak (Kolkata) Convener Sudhir Raniwala (Jaipur) Sourav Sarkar (Kolkata) Bikash Sinha (Kolkata) Chair Dinesh Srivastava (Kolkata) Raghava Varma (Mumbai) Yogendra P Viyogi (Bhubaneswar)Co-chair International Advisory Committee R Aymar,Switzerland Jean Paul Blaizot, France Peter Braun Münzinger, Germany Igor M Dremin, Russia Kari Eskola, Finland Jens Jorgen Gaardhoje,Denmark Rajiv V Gavai, India Hans-Ake Gustaffson, Sweden Hans Gutbrod, Germany Miklos Gyulassy, USA Timothy Hallman, USA Hideki Hamagaki, Japan Tetsuo Hatsuda, Japan Huan-Zhong Huang, USA Barbara Jacak, USA Peter Jenni, Switzerland Taka Kajino, Japan Takeshi Kodama, Brazil T D Lee, USA Peter Levai, Hungary Luciano Maiani, Italy Larry McLerran, USA Berndt Müller, USA Guy Paic, Mexico Sibaji Raha, India Lodovico Riccati, Italy Hans Georg Ritter, USA Helmut Satz, Germany Jurgen Schukraft, Switzerland Yves Schutz, France Edward V Shuryak, USA Johanna Stachel, Germany Horst Stöcker, Germany Itzhak Tserruya, Israel Xin-Nian Wang, USA Bolek Wyslouch, USA Glenn R Young, USA William A Zajc, USA Wen-Long Zhan, China

Molecular simulations of diffusion in electrolytes

NASA Astrophysics Data System (ADS)

Wheeler, Dean Richard

This work demonstrates new methodologies for simulating multicomponent diffusion in concentrated solutions using molecular dynamics (MD). Experimental diffusion data for concentrated multicomponent solutions are often lacking, as are accurate methods of predicting diffusion for nonideal solutions. MD can be a viable means of understanding and predicting multicomponent diffusion. While there have been several prior reports of MD simulations of mutual diffusion, no satisfactory expressions for simulating Stefan-Maxwell diffusivities for an arbitrary number of species exist. The approaches developed here allow for the computation of a full diffusion matrix for any number of species in both nonequilibrium and equilibrium MD ensembles. Our nonequilibrium approach is based on the application of constant external fields to drive species diffusion. Our equilibrium approach uses a newly developed Green-Kubo formula for Stefan-Maxwell diffusivities. In addition, as part of this work, we demonstrate a widely applicable means of increasing the computational efficiency of the Ewald sum, a technique for handling long-range Coulombic interactions in simulations. The theoretical development is applicable to any solution which can be simulated using MD; nevertheless, our primary interest is in electrochemical applications. To this end, the methods are tested by simulations of aqueous salt solutions and lithium-battery electrolytes. KCl and NaCl aqueous solutions were simulated over the concentration range 1 to 4 molal. Intermolecular-potential models were parameterized for these transport-based simulations. This work is the first to simulate all three independent diffusion coefficients for aqueous NaCl and KCl solutions. The results show that the nonequilibrium and equilibrium methods are consistent with each other, and in moderate agreement with experiment. We simulate lithium-battery electrolytes containing LiPF6 in propylene carbonate and mixed ethylene carbonate

Mass transport in gas diffusion layers of proton exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Martinez, Michael J.

This dissertation describes fundamental properties of gas diffusion media (GDM) and their relationship to the mass transport in proton exchange membrane fuel cells (PEMFCs). First, the accuracy of solving the multi-component equations for PEMFC by using a computational fluid dynamics (CFD) technique is examined. This technique uses an approximated multi-component (AMC) model with a correction term that guarantees the overall mass balance. Accuracy is assessed by comparing the species concentrations computed with the Maxwell-Stefan and the AMC model. This comparison is important because the structure of some CFD programs does not permit the direct use of the Maxwell-Stefan equations. Here, it is shown that the maximum error between the two models is less than 5%. Second, the ratio of tortuosity to porosity, known as the MacMullin number, is reported for different carbon cloth and carbon paper GDM. This analysis show that only carbon cloths GDM follow the commonly accepted Bruggeman equation and that carbon paper GDM have a different relationship between the tortuosity and the porosity. These differences are discussed in terms of path length created by the orientation of fibers of each GDM. Third, data for the hydrophilic and hydrophobic pore size distributions (PSD) are presented for two types of GDM used in PEMFCs. The data were obtained by using two common measurement methods, intrusion porosimetry (IP) and the method of standard porosimetry (MSP). The use of multiple working fluids to access hydrophilic and hydrophobic pores is discussed as well as the limitations associated with structural changes of the GDM during the tests. The differences in interpretations of the data between the two methods for both GDM have significant implications relative to the distribution of hydrophilic and hydrophobic pores that control liquid water transport. Finally, a two-phase mass-transport-only model (MTOM) that incorporates the tortuosity and the PSD data described above is

Discussion of "Simple design criterion for residual energy on embankment dam stepped spillways" by Stefan Felder and Hubert Chanson

USDA-ARS?s Scientific Manuscript database

Researchers from the University of Queensland of New South Wales provided guidance to designers regarding the hydraulic performance of embankment dam stepped spillways. Their research compares a number of high-quality physical model data sets from multiple laboratories, emphasizing the variability ...

Geometric and Topological Methods for Quantum Field Theory

NASA Astrophysics Data System (ADS)

Cardona, Alexander; Contreras, Iván.; Reyes-Lega, Andrés. F.

2013-05-01

Introduction; 1. A brief introduction to Dirac manifolds Henrique Bursztyn; 2. Differential geometry of holomorphic vector bundles on a curve Florent Schaffhauser; 3. Paths towards an extension of Chern-Weil calculus to a class of infinite dimensional vector bundles Sylvie Paycha; 4. Introduction to Feynman integrals Stefan Weinzierl; 5. Iterated integrals in quantum field theory Francis Brown; 6. Geometric issues in quantum field theory and string theory Luis J. Boya; 7. Geometric aspects of the standard model and the mysteries of matter Florian Scheck; 8. Absence of singular continuous spectrum for some geometric Laplacians Leonardo A. Cano García; 9. Models for formal groupoids Iván Contreras; 10. Elliptic PDEs and smoothness of weakly Einstein metrics of Hölder regularity Andrés Vargas; 11. Regularized traces and the index formula for manifolds with boundary Alexander Cardona and César Del Corral; Index.

Aerodynamic features of flames in premixed gases

NASA Technical Reports Server (NTRS)

Oppenheim, A. K.

1984-01-01

A variety of experimentally established flame phenomena in premixed gases are interpreted by relating them to basic aerodynamic properties of the flow field. On this basis the essential mechanism of some well known characteristic features of flames stabilized in the wake of a bluff-body or propagating in ducts are revealed. Elementary components of the flame propagation process are shown to be: rotary motion, self-advancement, and expansion. Their consequences are analyzed under a most strict set of idealizations that permit the flow field to be treated as potential in character, while the flame is modelled as a Stefan-like interface capable of exerting a feed-back effect upon the flow field. The results provide an insight into the fundamental fluid-mechanical reasons for the experimentally observed distortions of the flame front, rationalizing in particular its ability to sustain relatively high flow velocities at amazingly low normal burning speeds.

Medical beam monitor—Pre-clinical evaluation and future applications

NASA Astrophysics Data System (ADS)

Frais-Kölbl, Helmut; Griesmayer, Erich; Schreiner, Thomas; Georg, Dietmar; Pernegger, Heinz

2007-10-01

Future medical ion beam applications for cancer therapy which are based on scanning technology will require advanced beam diagnostics equipment. For a precise analysis of beam parameters we want to resolve time structures in the range of microseconds to nanoseconds. A prototype of an advanced beam monitor was developed by the University of Applied Sciences Wiener Neustadt and its research subsidiary Fotec in co-operation with CERN RD42, Ohio State University and the Jožef Stefan Institute in Ljubljana. The detector is based on polycrystalline Chemical Vapor Deposition (pCVD) diamond substrates and is equipped with readout electronics up to 2 GHz analog bandwidth. In this paper we present the design of the pCVD-detector system and results of tests performed in various particle accelerator based facilities. Measurements performed in clinical high energy photon beams agreed within 1.2% with results obtained by standard ionization chambers.

Analytical solutions for benchmarking cold regions subsurface water flow and energy transport models: one-dimensional soil thaw with conduction and advection

USGS Publications Warehouse

Kurylyk, Barret L.; McKenzie, Jeffrey M; MacQuarrie, Kerry T. B.; Voss, Clifford I.

2014-01-01

Numerous cold regions water flow and energy transport models have emerged in recent years. Dissimilarities often exist in their mathematical formulations and/or numerical solution techniques, but few analytical solutions exist for benchmarking flow and energy transport models that include pore water phase change. This paper presents a detailed derivation of the Lunardini solution, an approximate analytical solution for predicting soil thawing subject to conduction, advection, and phase change. Fifteen thawing scenarios are examined by considering differences in porosity, surface temperature, Darcy velocity, and initial temperature. The accuracy of the Lunardini solution is shown to be proportional to the Stefan number. The analytical solution results obtained for soil thawing scenarios with water flow and advection are compared to those obtained from the finite element model SUTRA. Three problems, two involving the Lunardini solution and one involving the classic Neumann solution, are recommended as standard benchmarks for future model development and testing.

Effects of surface poisons on the oxidation of binary alloys

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

Hagan, P.S.; Polizzotti, R.S.; Luckman, G.

1985-10-01

A system of reaction-diffusion equations describing the oxidation of binary alloys in environments containing small amounts of surface poisons is analyzed. These poisons reduce the oxygen flux into the alloy, which causes the alloy to oxidize in two stages.During the initial stage, the oxidation reaction occurs in a stationary boundary layer at the alloy surface. Consequently, a thin zone containing a very high concentration of the metal oxide is created at the alloy surface. During the second stage, the oxidation reaction occurs in a moving boundary layer. This leads to a Stefan problem, which is analyzed by using asymptotic andmore » numerical techniques. By comparing the solutions to those of alloys in unpoisoned environments, it is concluded that surface poisons can lead to the formation of protective external oxide scales in alloys which would not normally form such scales. 11 references.« less

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

Baig, Mohammad Saad, E-mail: saad110baig@gmail.com; Chakraborty, Brahmananda; Ramaniah, Lavanya M.

NaF-ZrF{sub 4} is used as a waste incinerator and as a coolant in Generation IV reactors.Structural and dynamical properties of molten NaF-ZrF{sub 4} system were studied along with Onsagercoefficients and Maxwell–Stefan (MS) Diffusivities applying Green–Kubo formalism and molecular dynamics (MD) simulations. The zirconium ions are found to be 8 fold coordinated with fluoride ions for all temperatures and concentrations. All the diffusive flux correlations show back-scattering. Even though the MS diffusivities are expected to depend very lightly on the composition because of decoupling of thermodynamic factor, the diffusivity Đ{sub Na-F} shows interesting behavior with the increase in concentration of ZrF{submore » 4}. This is because of network formation in NaF-ZrF{sub 4}. Positive entropy constraints have been plotted to authenticate negative diffusivities observed.« less

Contribution of insurance data to cost assessment of coastal flood damage to residential buildings: insights gained from Johanna (2008) and Xynthia (2010) storm events

NASA Astrophysics Data System (ADS)

André, C.; Monfort, D.; Bouzit, M.; Vinchon, C.

2013-08-01

There are a number of methodological issues involved in assessing damage caused by natural hazards. The first is the lack of data, due to the rarity of events and the widely different circumstances in which they occur. Thus, historical data, albeit scarce, should not be neglected when seeking to build ex-ante risk management models. This article analyses the input of insurance data for two recent severe coastal storm events, to examine what causal relationships may exist between hazard characteristics and the level of damage incurred by residential buildings. To do so, data was collected at two levels: from lists of about 4000 damage records, 358 loss adjustment reports were consulted, constituting a detailed damage database. The results show that for flooded residential buildings, over 75% of reconstruction costs are associated with interior elements, with damage to structural components remaining very localised and negligible. Further analysis revealed a high scatter between costs and water depth, suggesting that uncertainty remains high in drawing up damage functions with insurance data alone. Due to the paper format of the loss adjustment reports, and the lack of harmonisation between their contents, the collection stage called for a considerable amount of work. For future events, establishing a standardised process for archiving damage information could significantly contribute to the production of such empirical damage functions. Nevertheless, complementary sources of data on hazards and asset vulnerability parameters will definitely still be necessary for damage modelling; multivariate approaches, crossing insurance data with external material, should also be investigated more deeply.

Contribution of insurance data to cost assessment of coastal flood damage to residential buildings: insights gained from Johanna (2008) and Xynthia (2010) storm events

NASA Astrophysics Data System (ADS)

André, C.; Monfort, D.; Bouzit, M.; Vinchon, C.

2013-03-01

There are a number of methodological issues involved in assessing damage caused by natural hazards. The first is the lack of data, due to the rarity of events and the widely different circumstances in which they occur. Thus, historical data, albeit scarce, should not be neglected when seeking to build ex-ante risk management models. This article analyses the input of insurance data for two recent severe coastal storm events, to examine what causal relationships may exist between hazard characteristics and the level of damage incurred by residential buildings. To do so, data was collected at two levels: from lists of about 4000 damage records, 358 loss adjustment reports were consulted, constituting a detailed damage database. The results show that for flooded residential buildings, over 75% of reconstruction costs are associated with interior elements, damage to structural components remaining very localised and negligible. Further analysis revealed a high scatter between costs and water depth, suggesting that uncertainty remains high in drawing up damage functions with insurance data alone. Due to the paper format of the loss adjustment reports and the lack of harmonisation between their contents, the collection stage called for a considerable amount of work. For future events, establishing a standardised process for archiving damage information could significantly contribute to the production of such empirical damage functions. Nevertheless, complementary sources of data on hazards and asset vulnerability parameters, will definitely still be necessary for damage modelling and multivariate approaches, crossing insurance data with external material, should also be deeper investigated.

MONET, HET and SALT and asteroseismological observations and theory in Göttingen

NASA Astrophysics Data System (ADS)

Schuh, S.; Hessman, F. V.; Dreizler, S.; Kollatschny, W.; Glatzel, W.

2007-06-01

The Göttingen stellar astrophysics group, headed by Stefan Dreizler, conducts research on extrasolar planets and their host stars, on lower-main sequence stars, and on evolved compact objects, in particular hot white dwarfs (including PG 1159 objects, magnetic WDs and cataclysmic variables), and subdwarf B stars. In addition to sophisticated NLTE spectral analyses of these stars, which draw on the extensive stellar atmosphere modelling experience of the group, we actively develop and apply a variety of photometric monitoring and time-resolved spectroscopic techniques to address time-dependent phenomena. With the new instrumentational developments described below, we plan to continue the study of variable white dwarfs (GW Vir, DB and ZZ Ceti variables) and in particular sdB EC 14026 and PG 1617 pulsators which already constitute a main focus, partly within the Whole Earth Telescope (WET/DARC), http://www.physics.udel.edu/~jlp/darc/) collaboration, on a new level. Additional interest is directed towards strange mode instabilities in Wolf Rayet stars.

The black hole quantum atmosphere

NASA Astrophysics Data System (ADS)

Dey, Ramit; Liberati, Stefano; Pranzetti, Daniele

2017-11-01

Ever since the discovery of black hole evaporation, the region of origin of the radiated quanta has been a topic of debate. Recently it was argued by Giddings that the Hawking quanta originate from a region well outside the black hole horizon by calculating the effective radius of a radiating body via the Stefan-Boltzmann law. In this paper we try to further explore this issue and end up corroborating this claim, using both a heuristic argument and a detailed study of the stress energy tensor. We show that the Hawking quanta originate from what might be called a quantum atmosphere around the black hole with energy density and fluxes of particles peaked at about 4 MG, running contrary to the popular belief that these originate from the ultra high energy excitations very close to the horizon. This long distance origin of Hawking radiation could have a profound impact on our understanding of the information and transplanckian problems.

Temperature monitoring by infrared radiation measurements during ArF excimer laser ablation with cornea

NASA Astrophysics Data System (ADS)

Ishihara, Miya; Arai, Tsunenori; Sato, Shunichi; Nakano, Hironori; Obara, Minoru; Kikuchi, Makoto

1999-06-01

We measured infrared thermal radiation from porcine cornea during various fluences ArF excimer laser ablations with 1 microsecond(s) rise time. To obtain absolute temperature by means of Stefan-Boltzman law of radiation, we carried out a collection efficiency and detective sensitivity by a pre-experiment using panel heater. We measured the time course of the thermal radiation intensity with various laser fluences. We studied the relation between the peak cornea temperature during the ablation and irradiation fluences. We found the ablation situations, i.e., sub-ablation threshold, normal thermal ablation, and over-heated ablation, may be judged by both of the measured temperature transient waveforms and peak temperature. The boundary fluences corresponding to normal thermal ablation were 90 and 160 mJ/cm2. Our fast remote temperature monitoring during cornea ablation might be useful to control ablation quality/quantity of the cornea ArF laser ablation, that is PRK.

Freeze-cast alumina pore networks: Effects of freezing conditions and dispersion medium

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

Miller, S. M.; Xiao, X.; Faber, K. T.

Alumina ceramics were freeze-cast from water- and camphene-based slurries under varying freezing conditions and examined using X-ray computed tomography (XCT). Pore network characteristics, i.e., porosity, pore size, geometric surface area, and tortuosity, were measured from XCT reconstructions and the data were used to develop a model to predict feature size from processing conditions. Classical solidification theory was used to examine relationships between pore size, temperature gradients, and freezing front velocity. Freezing front velocity was subsequently predicted from casting conditions via the two-phase Stefan problem. Resulting models for water-based samples agreed with solidification-based theories predicting lamellar spacing of binary eutectic alloys,more » and models for camphene-based samples concurred with those for dendritic growth. Relationships between freezing conditions and geometric surface area were also modeled by considering the inverse relationship between pore size and surface area. Tortuosity was determined to be dependent primarily on the type of dispersion medium. (C) 2015 Elsevier Ltd. All rights reserved.« less

Cold Heat Release Characteristics of Solidified Oil Droplet-Water Solution Latent Heat Emulsion by Air Bubbles

NASA Astrophysics Data System (ADS)

Inaba, Hideo; Morita, Shin-Ichi

The present work investigates the cold heat-release characteristics of the solidified oil droplets (tetradecane, C14H30, freezing point 278.9 K)/water solution emulsion as a latent heat-storage material having a low melting point. An air bubbles-emulsion direct-contact heat exchange method is selected for the cold heat-results from the solidified oil droplet-emulsion layer. This type of direct-contact method results in the high thermal efficiency. The diameter of air bubbles in the emulsion increases as compared with that in the pure water. The air bubbles blown from a nozzle show a strong mixing behavior during rising in the emulsion. The temperature effectiveness, the sensible heat release time and the latent heat release time have been measured as experimental parameters. The useful nondimensional emulsion level equations for these parameters have been derived in terms of the nondimensional emalsion level expressed the emulsion layer dimensions, Reynolds number for air flow, Stefan number and heat capacity ratio.

Laser-Bioplasma Interaction: The Blood Type Transmutation Induced by Multiple Ultrashort Wavelength Laser Beams

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2015-11-01

The interaction of ultrashort wavelength multi laser beams with the flowing blood thin films leads to the transmutation of the blood types A, B, and AB into O type. This is a novel mechanism of importance for the transfusion medicine. Laser radiation is in resonance with the eigen-frequency modes of the antigen proteins and forces the proteins to parametrically oscillate until they get kicked out from the surface. The stripping away of antigens is done by the scanning-multiple-lasers of a high repetition rate in the blue-purple frequency domain. The guiding-lasers are in the red-green frequency domain. The laser force, (parametric interaction with the antigen eigen-oscillation), upon the antigen protein molecule must exceed its weight. The scanning laser beam is partially reflected as long as the antigen(s) is not eliminated. The process of the protein detachment can last a few minutes. Supported by Nikola Tesla Labs., Stefan University.

European Physical Society Conference on High Energy Physics

NASA Astrophysics Data System (ADS)

The European Physical Society Conference on High Energy Physics, organized by the High Energy and Particle Physics Division of the European Physical Society, is a major international conference that reviews biennially since 1971 the state of our knowledge of the fundamental constituents of matter and their interactions. The latest conferences in this series were held in Stockholm, Grenoble, Krakow, Manchester, Lisbon, and Aachen. Jointly organized by the Institute of High Energy Physics of the Austrian Academy of Sciences, the University of Vienna, the Vienna University of Technology, and the Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, the 23rd edition of this conference took place in Vienna, Austria. Among the topics covered were Accelerators, Astroparticle Physics, Cosmology and Gravitation, Detector R&D and Data Handling, Education and Outreach, Flavour Physics and Fundamental Symmetries, Heavy Ion Physics, Higgs and New Physics, Neutrino Physics, Non-Perturbative Field Theory and String Theory, QCD and Hadronic Physics, as well as Top and Electroweak Physics.

A combined volume-of-fluid method and low-Mach-number approach for DNS of evaporating droplets in turbulence

NASA Astrophysics Data System (ADS)

Dodd, Michael; Ferrante, Antonino

2017-11-01

Our objective is to perform DNS of finite-size droplets that are evaporating in isotropic turbulence. This requires fully resolving the process of momentum, heat, and mass transfer between the droplets and surrounding gas. We developed a combined volume-of-fluid (VOF) method and low-Mach-number approach to simulate this flow. The two main novelties of the method are: (i) the VOF algorithm captures the motion of the liquid gas interface in the presence of mass transfer due to evaporation and condensation without requiring a projection step for the liquid velocity, and (ii) the low-Mach-number approach allows for local volume changes caused by phase change while the total volume of the liquid-gas system is constant. The method is verified against an analytical solution for a Stefan flow problem, and the D2 law is verified for a single droplet in quiescent gas. We also demonstrate the schemes robustness when performing DNS of an evaporating droplet in forced isotropic turbulence.

Effective Tolman temperature induced by trace anomaly

NASA Astrophysics Data System (ADS)

Eune, Myungseok; Gim, Yongwan; Kim, Wontae

2017-04-01

Despite the finiteness of stress tensor for a scalar field on the four-dimensional Schwarzschild black hole in the Israel-Hartle-Hawking vacuum, the Tolman temperature in thermal equilibrium is certainly divergent on the horizon due to the infinite blue-shift of the Hawking temperature. The origin of this conflict is due to the fact that the conventional Tolman temperature was based on the assumption of a traceless stress tensor, which is, however, incompatible with the presence of the trace anomaly responsible for the Hawking radiation. Here, we present an effective Tolman temperature which is compatible with the presence of the trace anomaly by using the modified Stefan-Boltzmann law. Eventually, the effective Tolman temperature turns out to be finite everywhere outside the horizon, and so an infinite blue-shift of the Hawking temperature at the event horizon does not appear any more. In particular, it is vanishing on the horizon, so that the equivalence principle is exactly recovered at the horizon.

Eruption rate, area, and length relationships for some Hawaiian lava flows

NASA Technical Reports Server (NTRS)

Pieri, David C.; Baloga, Stephen M.

1986-01-01

The relationships between the morphological parameters of lava flows and the process parameters of lava composition, eruption rate, and eruption temperature were investigated using literature data on Hawaiian lava flows. Two simple models for lava flow heat loss by Stefan-Boltzmann radiation were employed to derive eruption rate versus planimetric area relationship. For the Hawaiian basaltic flows, the eruption rate is highly correlated with the planimetric area. Moreover, this observed correlation is superior to those from other obvious combinations of eruption rate and flow dimensions. The correlations obtained on the basis of the two theoretical models, suggest that the surface of the Hawaiian flows radiates at an effective temperature much less than the inner parts of the flowing lava, which is in agreement with field observations. The data also indicate that the eruption rate versus planimetric area correlations can be markedly degraded when data from different vents, volcanoes, and epochs are combined.

Experimental power density distribution benchmark in the TRIGA Mark II reactor

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

Snoj, L.; Stancar, Z.; Radulovic, V.

2012-07-01

In order to improve the power calibration process and to benchmark the existing computational model of the TRIGA Mark II reactor at the Josef Stefan Inst. (JSI), a bilateral project was started as part of the agreement between the French Commissariat a l'energie atomique et aux energies alternatives (CEA) and the Ministry of higher education, science and technology of Slovenia. One of the objectives of the project was to analyze and improve the power calibration process of the JSI TRIGA reactor (procedural improvement and uncertainty reduction) by using absolutely calibrated CEA fission chambers (FCs). This is one of the fewmore » available power density distribution benchmarks for testing not only the fission rate distribution but also the absolute values of the fission rates. Our preliminary calculations indicate that the total experimental uncertainty of the measured reaction rate is sufficiently low that the experiments could be considered as benchmark experiments. (authors)« less

Surface tension of evaporating nanofluid droplets

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

Chen, Ruey-Hung; Phuoc, Tran X.; Martello, Donald

2011-05-01

Measurements of nanofluid surface tension were made using the pendant droplet method. Three different types of nanoparticles were used - laponite, silver and Fe 2O 3 - with de-ionized water (DW) as the base fluid. The reported results focus on the following categories; (1) because some nanoparticles require surfactants to form stable colloids, the individual effects of the surfactant and the particles were investigated; (2) due to evaporation of the pendant droplet, the particle concentration increases, affecting the apparent surface tension; (3) because of the evaporation process, a hysteresis was found where the evaporating droplet can only achieve lower valuesmore » of surface tension than that of nanofluids at the same prepared concentrations: and (4) the Stefan equation relating the apparent surface tension and heat of evaporation was found to be inapplicable for nanofluids investigated. Comparisons with findings for sessile droplets are also discussed, pointing to additional effects of nanoparticles other than the non-equilibrium evaporation process.« less

Qualification of heavy water based irradiation device in the JSI TRIGA reactor for irradiations of FT-TIMS samples for nuclear safeguards

NASA Astrophysics Data System (ADS)

Radulović, Vladimir; Kolšek, Aljaž; Fauré, Anne-Laure; Pottin, Anne-Claire; Pointurier, Fabien; Snoj, Luka

2018-03-01

The Fission Track Thermal Ionization Mass Spectrometry (FT-TIMS) method is considered as the reference method for particle analysis in the field of nuclear Safeguards for measurements of isotopic compositions (fissile material enrichment levels) in micrometer-sized uranium particles collected in nuclear facilities. An integral phase in the method is the irradiation of samples in a very well thermalized neutron spectrum. A bilateral collaboration project was carried out between the Jožef Stefan Institute (JSI, Slovenia) and the Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA, France) to determine whether the JSI TRIGA reactor could be used for irradiations of samples for the FT-TIMS method. This paper describes Monte Carlo simulations, experimental activation measurements and test irradiations performed in the JSI TRIGA reactor, firstly to determine the feasibility, and secondly to design and qualify a purpose-built heavy water based irradiation device for FT-TIMS samples. The final device design has been shown experimentally to meet all the required performance specifications.

Commentary on muscle dysmorphia as an addiction: A response to Grant (2015) and Nieuwoudt (2015)

PubMed Central

FOSTER, ANDREW C.; SHORTER, GILLIAN W.

2015-01-01

Background Following the publication of our paper ‘Muscle Dysmorphia: Could it be classified as an addiction to body image?’ in the Journal of Behavioral Addictions, two commentaries by Jon Grant and Johanna Nieuwoudt were published in response to our paper. Method Using the ‘addiction components model’, our main contention is that muscle dysmorphia (MD) actually comprises a number of different actions and behaviors and that the actual addictive activity is the maintaining of body image via a number of different activities such as bodybuilding, exercise, eating certain foods, taking specific drugs (e.g., anabolic steroids), shopping for certain foods, food supplements, and purchase or use of physical exercise accessories. This paper briefly responds to these two commentaries. Results While our hypothesized specifics relating to each addiction component sometimes lack empirical support (as noted explicitly by both Nieuwoudt and Grant), we still believe that our main thesis (that almost all the thoughts and behaviors of those with MD revolve around the maintenance of body image) is something that could be empirically tested in future research by those who already work in the area. Conclusions We hope that the ‘Addiction to Body Image’ model we proposed provides a new framework for carrying out work in both empirical and clinical settings. The idea that MD could potentially be classed as an addiction cannot be negated on theoretical grounds as many people in the addiction field are turning their attention to research in new areas of behavioral addiction. PMID:25786494

Costs and deaths of landslides in Europe

NASA Astrophysics Data System (ADS)

Haque, Ubydul; Blum, Philipp

2016-04-01

Landslides cause human and large economic losses worldwide and also in Europe. However, the quantification of associated costs and deaths is highly underestimated and still incomplete, thus the estimation of landslide costs and risk is still rather ambitious. Hence, in this study a spatio-temporal analysis of fatal landslides is presented for 27 European countries from 1995-2014. These landslides are mainly concentrated in mountainous areas. A total of 1370 fatalities are reported resulting from 476 landslides. The highest fatalities with 335 are observed in Turkey. In general, an increasing trend of fatal landslides is recognized starting in 2008. The latter is almost certainly triggered by an increase in natural extreme events such as storms (i.e. heavy rainfall) and floods. The highest annual economic loss is observed in Italy with 3.9 billion Euro per year. In contrast, in Germany the annual total loss is only about 0.3 billion Euro. The results of this study serves as an initial baseline information for further risk studies integrating landslide locations, local land use data, cost data, and will therefore certainly support the studied countries to better protect their citizens and assets. Acknowledgements We would like to acknowledge the valuable contributions by Paula F. da Silva, Peter Andersen, Jürgen Pilz, Ali Ardalan, Sergey R. Chalov, Jean-Philippe Malet, Mateja Jemec Auflič, Norina Andres, Eleftheria Poyiadji, Pedro C. Lamas, Wenyi Zhang, Igor Pesevski, Halldór G. Pétursson, Tayfun Kurt, Nikolai Dobrev, Juan Carlos García Davalillo, Matina Halkia, Stefano Ferri, George Gaprindashvili, Johanna Engström and David Keellings.

Inception of supraglacial channelization under turbulent flow conditions

NASA Astrophysics Data System (ADS)

Mantelli, E.; Camporeale, C.; Ridolfi, L.

2013-12-01

Glacier surfaces exhibit an amazing variety of meltwater-induced morphologies, ranging from small scale ripples and dunes on the bed of supraglacial channels to meandering patterns, till to large scale drainage networks. Even though the structure and geometry of these morphologies play a key role in the glacier melting processes, the physical-based modeling of such spatial patterns have attracted less attention than englacial and subglacial channels. In order to partially fill this gap, our work concerns the large scale channelization occurring on the ice slopes and focuses on the role of turbulence on the wavelength selection processes during the channelization inception. In a recent study[1], two of us showed that the morphological instability induced by a laminar film flowing over an ice bed is characterized by transversal length scales of order of centimeters. Being these scales much smaller than the spacing observed in the channelization of supraglacial drainage networks (that are of order of meters) and considering that the water films flowing on glaciers can exhibit Reynolds numbers larger than 104, we investigated the role of turbulence in the inception of channelization. The flow-field is modeled by means of two-dimensional shallow water equations, where Reynolds stresses are also considered. In the depth-averaged heat balance equation an incoming heat flux from air is assumed and forced convection heat exchange with the wall is taken into account, in addition to convection and diffusion in the liquid. The temperature profile in the ice is finally coupled to the liquid through Stefan equation. We then perform a linear stability analysis and, under the assumption of small Stefan number, we solve the differential eigenvalue problem analytically. As main outcome of such an analysis, the morphological instability of the ice-water interface is detected and investigated in a wide range of the independent parameters: longitudinal and transversal wavenumbers

Influence of the Stefan Flow on Heat Transfer in the System "Gas-Solid Particle" in Thermochemical Conversion of a Solid Fuel

NASA Astrophysics Data System (ADS)

Pechenegov, Yu. Ya.; Mrakin, A. N.

2017-09-01

Recommendations are presented on calculating interphase heat transfer in gas-disperse systems of plants for thermochemical conversion of ground solid fuel. An analysis is made of the influence of the gas release of fuel particles on the heat transfer during their heating. It is shown that in the processes of thermal treatment of oil shales, the presence of gas release reduces substantially the intensity of interphase heat transfer compared to the heat transfer in the absence of thermochemical decomposition of the solid phase.

Effect of breathing-hole size on the electrochemical species in a free-breathing cathode of a DMFC

NASA Astrophysics Data System (ADS)

Hwang, J. J.; Wu, S. D.; Lai, L. K.; Chen, C. K.; Lai, D. Y.

A three-dimensional numerical model is developed to study the electrochemical species characteristics in a free-breathing cathode of a direct methanol fuel cell (DMFC). A perforated current collector is attached to the porous cathode that breathes the fresh air through an array of orifices. The radius of the orifice is varied to examine its effect on the electrochemical performance. Gas flow in the porous cathode is governed by the Darcy equation with constant porosity and permeability. The multi-species diffusive transports in the porous cathode are described using the Stefan-Maxwell equation. Electrochemical reaction on the surfaces of the porous matrices is depicted via the Butler-Volmer equation. The charge transports in the porous matrices are dealt with by Ohm's law. The coupled equations are solved by a finite-element-based CFD technique. Detailed distributions of electrochemical species characteristics such as flow velocities, species mass fractions, species fluxes, and current densities are presented. The optimal breathing-hole radius is derived from the current drawn out of the porous cathode under a fixed overpotential.

Multicomponent Diffusion of Penetrant Mixtures in Rubbery Polymers: A Molecular Dynamics Study

NASA Astrophysics Data System (ADS)

Bringuier, Stefan; Varady, Mark; Knox, Craig; Cabalo, Jerry; Pearl, Thomas; Mantooth, Brent

The importance of understanding transport of chemical species across liquid-solid boundaries is of particular interest in the decontamination of harmful chemicals absorbed within polymeric materials. To characterize processes associated with liquid-phase extraction of absorbed species from polymers, it is necessary to determine an appropriate physical description of species transport in multicomponent systems. The Maxwell-Stefan (M-S) formulation is a rigorous description of mass transport in multicomponent solutions, in which, mutual diffusivities determine the degree of relative motion between interacting molecules in response to a chemical potential gradient. The work presented focuses on the determination of M-S diffusivities from molecular dynamics (MD) simulations of nerve agent O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate (VX), water, and methanol mixtures within a poly(dimethylsiloxane) matrix. We investigate the composition dependence of M-S diffusivities and compare the results to values predicted using empirical relations for binary and ternary mixtures. Finally, we highlight the pertinent differences in molecular mechanisms associated with species transport and employ non-equilibrium MD to probe transport across the mixture-polymer interface.

[Severely increased serum lipid levels in diabetic ketoacidosis - case report].

PubMed

Stefansson, Hrafnkell; Sigvaldason, Kristinn; Kjartansson, Hilmar; Sigurjonsdottir, Helga Águsta

2017-01-01

Severe hypertriglyceridemia is a known, but uncommon complication of diabetic ketoacidosis. We discuss the case of a 23-year-old, previously healthy, woman who initially presented to the emergency department with abdominal pain. Grossly lipemic serum due to extremely high triglyceride (38.6 mmol/L) and cholesterol (23.2 mmol/L) levels were observed with a high blood glucose (23 mmol/L) and a low pH of 7.06 on a venous blood gas. She was treated successfully with fluids and insulin and had no sequale of pancreatitis or cerebral edema. Her triglycerides and cholesterol was normalized in three days and she was discharged home on insulin therapy after five days. Further history revealed a recent change in diet with no meat, fish or poultry consumption in the last 12 months and concomitantly an increase in carbohydrate intake which might have contributed to her extremely high serum lipid levels. This case demonstrates that clinicians should be mindful of the different presentations of diabetic ketoacidosis. Key words: diabetic ketoacidosis, hypertriglyceridemia, hyperlipidemia, vegan diet, carbohydrate diet. Correspondence: Hrafnkell Stefansson, hrafnkell.stefans@gmail.com.

Continuum mesoscopic framework for multiple interacting species and processes on multiple site types and/or crystallographic planes.

PubMed

Chatterjee, Abhijit; Vlachos, Dionisios G

2007-07-21

While recently derived continuum mesoscopic equations successfully bridge the gap between microscopic and macroscopic physics, so far they have been derived only for simple lattice models. In this paper, general deterministic continuum mesoscopic equations are derived rigorously via nonequilibrium statistical mechanics to account for multiple interacting surface species and multiple processes on multiple site types and/or different crystallographic planes. Adsorption, desorption, reaction, and surface diffusion are modeled. It is demonstrated that contrary to conventional phenomenological continuum models, microscopic physics, such as the interaction potential, determines the final form of the mesoscopic equation. Models of single component diffusion and binary diffusion of interacting particles on single-type site lattice and of single component diffusion on complex microporous materials' lattices consisting of two types of sites are derived, as illustrations of the mesoscopic framework. Simplification of the diffusion mesoscopic model illustrates the relation to phenomenological models, such as the Fickian and Maxwell-Stefan transport models. It is demonstrated that the mesoscopic equations are in good agreement with lattice kinetic Monte Carlo simulations for several prototype examples studied.

Observations of faint comets with the IUE

NASA Astrophysics Data System (ADS)

Festou, M.

1982-06-01

Spectral observations of eight comets, including seven periodic comets, made in the range 1150-3400 A with the IUE satellite are presented. Comet Bradfield, the sole nonperiodic comet observed, is found to exhibit strong OH and atomic hydrogen emissions from the decomposition of water, along with oxygen, carbon, sulfur, carbon disulfide, C2 and CO2(plus) emissions and a faint continuum due to dust at longer wavelengths. Comets Encke, Tuttle and Stefan-Oterma appear to have identical spectra in the UV, showing evidence of much gas, little dust and few ions (only CO2(plus) detected), and differing from comet Bradfield only in the lack of C2 emission. All eight comets observed by IUE, including Seargent, Meier, Borrelly and Panther, had the same chemical composition, consisting mainly of water with a few per mil or per cent CN, C2, C3 and CS. The water production rates of the periodic comets range from levels 6 times less to 11 times more than that of Comet Bradfield, which may be related to nuclear size or cometary age.

Phase-field simulations of velocity selection in rapidly solidified binary alloys

NASA Astrophysics Data System (ADS)

Fan, Jun; Greenwood, Michael; Haataja, Mikko; Provatas, Nikolas

2006-09-01

Time-dependent simulations of two-dimensional isothermal Ni-Cu dendrites are simulated using a phase-field model solved with a finite-difference adaptive mesh refinement technique. Dendrite tip velocity selection is examined and found to exhibit a transition between two markedly different regimes as undercooling is increased. At low undercooling, the dendrite tip growth rate is consistent with the kinetics of the classical Stefan problem, where the interface is assume to be in local equilibrium. At high undercooling, the growth velocity selected approaches a linear dependence on melt undercooling, consistent with the continuous growth kinetics of Aziz and with a one-dimensional steady-state phase-field asymptotic analysis of Ahmad [Phys. Rev. E 58, 3436 (1998)]. Our simulations are also consistent with other previously observed behaviors of dendritic growth as undercooling is increased. These include the transition of dendritic morphology to absolute stability and nonequilibrium solute partitioning. Our results show that phase-field models of solidification, which inherently contain a nonzero interface width, can be used to study the dynamics of complex solidification phenomena involving both equilibrium and nonequilibrium interface growth kinetics.

Calculations to Support On-line Neutron Spectrum Adjustment by Measurements with Miniature Fission Chambers in the JSI TRIGA Reactor

NASA Astrophysics Data System (ADS)

Kaiba, Tanja; Radulović, Vladimir; Žerovnik, Gašper; Snoj, Luka; Fourmentel, Damien; Barbot, LoÏc; Destouches, Christophe AE(; )

2018-01-01

Preliminary calculations were performed with the aim to establish optimal experimental conditions for the measurement campaign within the collaboration between the Jožef Stefan Institute (JSI) and Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA Cadarache). The goal of the project is to additionally characterize the neutron spectruminside the JSI TRIGA reactor core with focus on the measurement epi-thermal and fast part of the spectrum. Measurements will be performed with fission chambers containing different fissile materials (235U, 237Np and 242Pu) covered with thermal neutron filters (Cd and Gd). The changes in the detected signal and neutron flux spectrum with and without transmission filter were studied. Additional effort was put into evaluation of the effect of the filter geometry (e.g. opening on the top end of the filter) on the detector signal. After the analysis of the scoping calculations it was concluded to position the experiment in the outside core ring inside one of the empty fuel element positions.

Peer Instruction Materials for Light and Spectra

NASA Astrophysics Data System (ADS)

Lee, Kevin M.; Siedell, C. M.; Prather, E. E.

2008-05-01

This poster will describe a new set of materials from the ClassAction project focusing on light and spectra. We will identify the concepts covered in the Light and Spectroscopy Concept Inventory (LSCI) which include the electromagnetic spectrum, Doppler shift, Wien's Law, Stefan-Boltzmann Law, and Kirchhoff's Laws. We will then specifically address how these concepts are targeted by the questions and resources of the ClassAction module. ClassAction is a collection of materials designed to enhance the metacognitive skills of college and high school introductory astronomy students by promoting interactive engagement and providing rapid feedback. The main focus is dynamic peer instruction questions that can be projected in the classroom. Instructors have the capability to recast these questions into alternate permutations based on their own preferences and formative feedback from the class. The questions can be easily selected from a FLASH computer database and are accompanied by outlines, graphics, and simulations which the instructor can utilize to provide feedback. These materials are publicly available at http://astro.unl.edu and are funded by NSF grant #0404988.

Ice Layer Spreading along a Solid Substrate during Solidification of Supercooled Water: Experiments and Modeling.

PubMed

Schremb, Markus; Campbell, James M; Christenson, Hugo K; Tropea, Cameron

2017-05-16

The thermal influence of a solid wall on the solidification of a sessile supercooled water drop is experimentally investigated. The velocity of the initial ice layer propagating along the solid substrate prior to dendritic solidification is determined from videos captured using a high-speed video system. Experiments are performed for varying substrate materials and liquid supercooling. In contrast to recent studies at moderate supercooling, in the case of metallic substrates only a weak influence of the substrate's thermal properties on the ice layer velocity is observed. Using the analytical solution of the two-phase Stefan problem, a semiempirical model for the ice layer velocity is developed. The experimental data are well described for all supercooling levels in the entire diffusion limited solidification regime. For higher supercooling, the model overestimates the freezing velocity due to kinetic effects during molecular attachment at the solid-liquid interface, which are not accounted for in the model. The experimental findings of the present work offer a new perspective on the design of anti-icing systems.

Theory of Ion and Water Transport in Reverse-Osmosis Membranes

NASA Astrophysics Data System (ADS)

Oren, Y. S.; Biesheuvel, P. M.

2018-02-01

We present a theory for ion and water transport through reverse-osmosis (RO) membranes based on a Maxwell-Stefan framework combined with hydrodynamic theory for the reduced motion of particles in thin pores. We take into account all driving forces and frictions both on the fluid (water) and on the ions including ion-fluid friction and ion-wall friction. By including the acid-base characteristic of the carbonic acid system, the boric acid system, H3O+/OH- , and the membrane charge, we locally determine p H , the effective charge of the membrane, and the dissociation degree of carbonic acid and boric acid. We present calculation results for an experiment with fixed feed concentration, where effluent composition is a self-consistent function of fluxes through the membrane. A comparison with experimental results from literature for fluid flow vs pressure, and for salt and boron rejection, shows that our theory agrees very well with the available data. Our model is based on realistic assumptions for the effective size of the ions and makes use of a typical pore size of a commercial RO membrane.

Validation of a numerical method for interface-resolving simulation of multicomponent gas-liquid mass transfer and evaluation of multicomponent diffusion models

NASA Astrophysics Data System (ADS)

Woo, Mino; Wörner, Martin; Tischer, Steffen; Deutschmann, Olaf

2018-03-01

The multicomponent model and the effective diffusivity model are well established diffusion models for numerical simulation of single-phase flows consisting of several components but are seldom used for two-phase flows so far. In this paper, a specific numerical model for interfacial mass transfer by means of a continuous single-field concentration formulation is combined with the multicomponent model and effective diffusivity model and is validated for multicomponent mass transfer. For this purpose, several test cases for one-dimensional physical or reactive mass transfer of ternary mixtures are considered. The numerical results are compared with analytical or numerical solutions of the Maxell-Stefan equations and/or experimental data. The composition-dependent elements of the diffusivity matrix of the multicomponent and effective diffusivity model are found to substantially differ for non-dilute conditions. The species mole fraction or concentration profiles computed with both diffusion models are, however, for all test cases very similar and in good agreement with the analytical/numerical solutions or measurements. For practical computations, the effective diffusivity model is recommended due to its simplicity and lower computational costs.

Vitrification and levitation of a liquid droplet on liquid nitrogen.

PubMed

Song, Young S; Adler, Douglas; Xu, Feng; Kayaalp, Emre; Nureddin, Aida; Anchan, Raymond M; Maas, Richard L; Demirci, Utkan

2010-03-09

The vitrification of a liquid occurs when ice crystal formation is prevented in the cryogenic environment through ultrarapid cooling. In general, vitrification entails a large temperature difference between the liquid and its surrounding medium. In our droplet vitrification experiments, we observed that such vitrification events are accompanied by a Leidenfrost phenomenon, which impedes the heat transfer to cool the liquid, when the liquid droplet comes into direct contact with liquid nitrogen. This is distinct from the more generally observed Leidenfrost phenomenon that occurs when a liquid droplet is self-vaporized on a hot plate. In the case of rapid cooling, the phase transition from liquid to vitrified solid (i.e., vitrification) and the levitation of droplets on liquid nitrogen (i.e., Leidenfrost phenomenon) take place simultaneously. Here, we investigate these two simultaneous physical events by using a theoretical model containing three dimensionless parameters (i.e., Stefan, Biot, and Fourier numbers). We explain theoretically and observe experimentally a threshold droplet radius during the vitrification of a cryoprotectant droplet in the presence of the Leidenfrost effect.

Vitrification and levitation of a liquid droplet on liquid nitrogen

PubMed Central

Song, Young S.; Adler, Douglas; Xu, Feng; Kayaalp, Emre; Nureddin, Aida; Anchan, Raymond M.; Maas, Richard L.; Demirci, Utkan

2010-01-01

The vitrification of a liquid occurs when ice crystal formation is prevented in the cryogenic environment through ultrarapid cooling. In general, vitrification entails a large temperature difference between the liquid and its surrounding medium. In our droplet vitrification experiments, we observed that such vitrification events are accompanied by a Leidenfrost phenomenon, which impedes the heat transfer to cool the liquid, when the liquid droplet comes into direct contact with liquid nitrogen. This is distinct from the more generally observed Leidenfrost phenomenon that occurs when a liquid droplet is self-vaporized on a hot plate. In the case of rapid cooling, the phase transition from liquid to vitrified solid (i.e., vitrification) and the levitation of droplets on liquid nitrogen (i.e., Leidenfrost phenomenon) take place simultaneously. Here, we investigate these two simultaneous physical events by using a theoretical model containing three dimensionless parameters (i.e., Stefan, Biot, and Fourier numbers). We explain theoretically and observe experimentally a threshold droplet radius during the vitrification of a cryoprotectant droplet in the presence of the Leidenfrost effect. PMID:20176969

Diffusion Coefficients from Molecular Dynamics Simulations in Binary and Ternary Mixtures

NASA Astrophysics Data System (ADS)

Liu, Xin; Schnell, Sondre K.; Simon, Jean-Marc; Krüger, Peter; Bedeaux, Dick; Kjelstrup, Signe; Bardow, André; Vlugt, Thijs J. H.

2013-07-01

Multicomponent diffusion in liquids is ubiquitous in (bio)chemical processes. It has gained considerable and increasing interest as it is often the rate limiting step in a process. In this paper, we review methods for calculating diffusion coefficients from molecular simulation and predictive engineering models. The main achievements of our research during the past years can be summarized as follows: (1) we introduced a consistent method for computing Fick diffusion coefficients using equilibrium molecular dynamics simulations; (2) we developed a multicomponent Darken equation for the description of the concentration dependence of Maxwell-Stefan diffusivities. In the case of infinite dilution, the multicomponent Darken equation provides an expression for [InlineEquation not available: see fulltext.] which can be used to parametrize the generalized Vignes equation; and (3) a predictive model for self-diffusivities was proposed for the parametrization of the multicomponent Darken equation. This equation accurately describes the concentration dependence of self-diffusivities in weakly associating systems. With these methods, a sound framework for the prediction of mutual diffusion in liquids is achieved.

Krypton-xenon separation properties of SAPO-34 zeolite materials and membranes

DOE PAGES

Hye Kwon, Yeon; Kiang, Christine; Benjamin, Emily; ...

2016-07-27

Separation of the radioisotope 85Kr from 136Xe is an important target during used nuclear fuel recycling. In this paper, we report a detailed study on the Kr and Xe adsorption, diffusion, and membrane permeation properties of the silicoaluminophosphate zeolite SAPO-34. Adsorption and diffusion measurements on SAPO-34 crystals indicate their potential for use in Kr-Xe separation membranes, but also highlight competing effects of adsorption and diffusion selectivity. SAPO-34 membranes are synthesized on α$-$alumina disk and tubular substrates via steam assisted conversion seeding and hydrothermal growth, and are characterized in detail. Membrane transport measurements reveal that SAPO-34 membranes can separate Kr frommore » Xe by molecular sieving, with Kr permeabilities around 50 Barrer and mixture selectivity of 25–30 for Kr at ambient or slight sub-ambient conditions. Finally, the membrane transport characteristics are modeled by the Maxwell-Stefan equations, whose predictions are in very good agreement with experiment and confirm the minimal competing effects of adsorption and diffusion.« less

Fluid Dynamics and Thermodynamics of Vapor Phase Crystal Growth

NASA Technical Reports Server (NTRS)

Wiedemeier, H.

1985-01-01

The ground-based research effort under this program is concerned with systematic studies of the effects of variations: (1) of the relative importance of buoyancy-driven convection, and (2) of diffusion and viscosity conditions on crystal properties. These experimental studies are supported by thermodynamic characterizations of the systems, based on which fluid dynamic parameters can be determined. The specific materials under investigation include: the GeSe-GeI4, Ge-GeI4, HgTe-HgI2, and Hg sub (1-x)Cd sub (x) Te-HgI2 systems. Mass transport rate studies of the GeSe-GeI system as a function of orientation of the density gradient relative to the gravity vector demonstrated the validity of flux anomalies observed in earlier space experiments. The investigation of the effects of inert gases on mass flux yielded the first experimental evidence for the existence of a boundary layer in closed ampoules. Combined with a thorough thermodynamic analysis, a transport model for diffusive flow including chemical vapor transport, sublimation, and Stefan flow was developed.

Isothermal Ice Crystallization Kinetics in the Gas-Diffusion Layer of a Proton-Exchange-Membrane Fuel Cell

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

Dursch, Thomas J.; Ciontea, Monica A.; Radke, Clayton J.

2011-12-01

Nucleation and growth of ice in the fibrous gas-diffusion layer (GDL) of a proton-exchange membrane fuel cell (PEMFC) are studied using isothermal differential scanning calorimetry (DSC). Isothermal crystallization rates and pseudo-steady-state nucleation rates are obtained as a function of subcooling from heat-flow and induction-time measurements. Kinetics of ice nucleation and growth are studied at two polytetrafluoroethylene (PTFE) loadings (0 and 10 wt %) in a commercial GDL for temperatures between 240 and 273 K. A nonlinear ice-crystallization rate expression is developed using Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory, in which the heat-transfer-limited growth rate is determined from the moving-boundary Stefan problem. Induction timesmore » follow a Poisson distribution and increase upon addition of PTFE, indicating that nucleation occurs more slowly on a hydrophobic fiber than on a hydrophilic fiber. The determined nucleation rates and induction times follow expected trends from classical nucleation theory. Finally, a validated rate expression is now available for predicting ice-crystallization kinetics in GDLs.« less

A multifluid model extended for strong temperature nonequilibrium

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

Chang, Chong

2016-08-08

We present a multifluid model in which the material temperature is strongly affected by the degree of segregation of each material. In order to track temperatures of segregated form and mixed form of the same material, they are defined as different materials with their own energy. This extension makes it necessary to extend multifluid models to the case in which each form is defined as a separate material. Statistical variations associated with the morphology of the mixture have to be simplified. Simplifications introduced include combining all molecularly mixed species into a single composite material, which is treated as another segregatedmore » material. Relative motion within the composite material, diffusion, is represented by material velocity of each component in the composite material. Compression work, momentum and energy exchange, virtual mass forces, and dissipation of the unresolved kinetic energy have been generalized to the heterogeneous mixture in temperature nonequilibrium. The present model can be further simplified by combining all mixed forms of materials into a composite material. Molecular diffusion in this case is modeled by the Stefan-Maxwell equations.« less

Direct fusion of geostationary meteorological satellite visible and infrared images based on thermal physical properties.

PubMed

Han, Lei; Wulie, Buzha; Yang, Yiling; Wang, Hongqing

2015-01-05

This study investigated a novel method of fusing visible (VIS) and infrared (IR) images with the major objective of obtaining higher-resolution IR images. Most existing image fusion methods focus only on visual performance and many fail to consider the thermal physical properties of the IR images, leading to spectral distortion in the fused image. In this study, we use the IR thermal physical property to correct the VIS image directly. Specifically, the Stefan-Boltzmann Law is used as a strong constraint to modulate the VIS image, such that the fused result shows a similar level of regional thermal energy as the original IR image, while preserving the high-resolution structural features from the VIS image. This method is an improvement over our previous study, which required VIS-IR multi-wavelet fusion before the same correction method was applied. The results of experiments show that applying this correction to the VIS image directly without multi-resolution analysis (MRA) processing achieves similar results, but is considerably more computationally efficient, thereby providing a new perspective on VIS and IR image fusion.

Direct Fusion of Geostationary Meteorological Satellite Visible and Infrared Images Based on Thermal Physical Properties

PubMed Central

Han, Lei; Wulie, Buzha; Yang, Yiling; Wang, Hongqing

2015-01-01

This study investigated a novel method of fusing visible (VIS) and infrared (IR) images with the major objective of obtaining higher-resolution IR images. Most existing image fusion methods focus only on visual performance and many fail to consider the thermal physical properties of the IR images, leading to spectral distortion in the fused image. In this study, we use the IR thermal physical property to correct the VIS image directly. Specifically, the Stefan-Boltzmann Law is used as a strong constraint to modulate the VIS image, such that the fused result shows a similar level of regional thermal energy as the original IR image, while preserving the high-resolution structural features from the VIS image. This method is an improvement over our previous study, which required VIS-IR multi-wavelet fusion before the same correction method was applied. The results of experiments show that applying this correction to the VIS image directly without multi-resolution analysis (MRA) processing achieves similar results, but is considerably more computationally efficient, thereby providing a new perspective on VIS and IR image fusion. PMID:25569749

Status of the deepwater cisco population of Lake Michigan

USGS Publications Warehouse

Smith, Stanford H.

1964-01-01

The species and size composition and the abundance of the cisco (Leucichthys spp.) population of Lake Michigan have undergone drastic changes since the sea lamprey became established in the 1940's. The changes were measured by the catches of gill nets of identical specifications fished at the same seasons, depths, and locations in 1930-32, 1954-55, and 1960-61. The two largest ciscoes (johannae and nigripinnis), exploited heavily in a highly selective fishery from the midnineteenth century to the early 1900's, were only sparsely represented in the catch in the 1930's and were absent from catches of the comparison surveys in 1954-55 and 1960-61. The species of intermediate size (alpenae, artedi, kiyi, reighardi, and zenithicus) constituted about two-thirds of the cisco stocks of the deepwater zone in the 1930's but declined to 23.9 and 6.4 percent in the 1950's and 1960's, respectively. Major causes of change were the increased fishing pressure and sea lamprey predation that accompanied the disappearance of the lake trout. The small, slow-growing cisco (hoyi) - the primary food of lake trout - which was not fished intensively, and was too small to suffer greatly from sea lamprey predation, increased from 31.0 percent of the catch in the 1930's to 76.1 percent in the 1950's and 93.6 percent in the 1960's. Consequences of the extreme imbalance of the cisco population have been a reduction in mean size of all species, extension of the range of the very abundant hoyi (formerly most abundant in moderately shallow areas) to almost all depths and sections of the lake, and possibly introgressive hybridization among the various species. The primary change in the fishery has been a shift from gill nets to more extensive use of trawls which can take the now abundant smaller fish.

Revisiting Lake Hämelsee: reconstructing abrupt Lateglacial climate transitions using state- of-the-art palaeoclimatological proxies

NASA Astrophysics Data System (ADS)

Engels, Stefan; Hoek, Wim; Lane, Christine; Sachse, Dirk; Wagner-Cremer, Friederike

2015-04-01

Lake Hämelsee (Germany) is one of the northernmost sites in NW Europe that has varved sediments throughout large parts of its Lateglacial and Early Holocene sediment sequence. Previous research on this site has shown its potential, in terms of chronological resolution and palaeoecological reconstructions, for reconstructing the abrupt transitions into and out of the Younger Dryas, the last cold period of the last glacial. The site was revisited during a 1-week summer school for Early Stage Researchers (2013), within the INTIMATE Example training and research project, supported by EU Cost Action ES0907. Two overlapping sediment sequences were retrieved from the centre of the lake during the summer school. These sediments have since formed the basis for follow-up research projects, which have sparked the collaboration of around 30 researchers in 12 laboratories across Europe. A chronological framework for the core has been composed from a combination of varve counting, radiocarbon dating and tephrochronology. Tephrostratigraphic correlations allow direct correlation and precise comparison of the record to marine and ice core records from the North Atlantic region, and other terrestrial European archives. Furthermore, the core is has been subjected to multiple sedimentological (e.g. XRF, loss-on-ignition), geochemical (e.g. lipid biomarkers, GDGTs) and palaeoecological (e.g. pollen, chironomids) proxy-based reconstructions of past environmental and climatic conditions. The results provide important insights into the nature of the abrupt climate transitions of the Lateglacial and Early Holocene, both locally and on a continental scale. The INTIMATE Example participants: Illaria Baneschi, Achim Brauer, Christopher Bronk Ramsey, Renee de Bruijn, Siwan Davies, Aritina Haliuc, Katalin Hubay, Gwydion Jones, Meike Müller, Johanna Menges, Josef Merkt, Tom Peters, Francien Peterse, Anneke ter Schure, Kathrin Schuetrumpf, Richard Staff, Falko Turner, Valerie van den Bos.

Oasis: online analysis of small RNA deep sequencing data.

PubMed

Capece, Vincenzo; Garcia Vizcaino, Julio C; Vidal, Ramon; Rahman, Raza-Ur; Pena Centeno, Tonatiuh; Shomroni, Orr; Suberviola, Irantzu; Fischer, Andre; Bonn, Stefan

2015-07-01

Oasis is a web application that allows for the fast and flexible online analysis of small-RNA-seq (sRNA-seq) data. It was designed for the end user in the lab, providing an easy-to-use web frontend including video tutorials, demo data and best practice step-by-step guidelines on how to analyze sRNA-seq data. Oasis' exclusive selling points are a differential expression module that allows for the multivariate analysis of samples, a classification module for robust biomarker detection and an advanced programming interface that supports the batch submission of jobs. Both modules include the analysis of novel miRNAs, miRNA targets and functional analyses including GO and pathway enrichment. Oasis generates downloadable interactive web reports for easy visualization, exploration and analysis of data on a local system. Finally, Oasis' modular workflow enables for the rapid (re-) analysis of data. Oasis is implemented in Python, R, Java, PHP, C++ and JavaScript. It is freely available at http://oasis.dzne.de. stefan.bonn@dzne.de Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

Theoretical and experimental fundamentals of designing promising technological equipment to improve efficiency and environmental safety of highly viscous oil recovery from deep oil reservoirs

NASA Astrophysics Data System (ADS)

Moiseyev, V. A.; Nazarov, V. P.; Zhuravlev, V. Y.; Zhuykov, D. A.; Kubrikov, M. V.; Klokotov, Y. N.

2016-12-01

The development of new technological equipment for the implementation of highly effective methods of recovering highly viscous oil from deep reservoirs is an important scientific and technical challenge. Thermal recovery methods are promising approaches to solving the problem. It is necessary to carry out theoretical and experimental research aimed at developing oil-well tubing (OWT) with composite heatinsulating coatings on the basis of basalt and glass fibers. We used the method of finite element analysis in Nastran software, which implements complex scientific and engineering calculations, including the calculation of the stress-strain state of mechanical systems, the solution of problems of heat transfer, the study of nonlinear static, the dynamic transient analysis of frequency characteristics, etc. As a result, we obtained a mathematical model of thermal conductivity which describes the steady-state temperature and changes in the fibrous highly porous material with the heat loss by Stefan-Boltzmann's radiation. It has been performed for the first time using the method of computer modeling in Nastran software environments. The results give grounds for further implementation of the real design of the OWT when implementing thermal methods for increasing the rates of oil production and mitigating environmental impacts.

ADMIT: a toolbox for guaranteed model invalidation, estimation and qualitative–quantitative modeling

PubMed Central

Streif, Stefan; Savchenko, Anton; Rumschinski, Philipp; Borchers, Steffen; Findeisen, Rolf

2012-01-01

Summary: Often competing hypotheses for biochemical networks exist in the form of different mathematical models with unknown parameters. Considering available experimental data, it is then desired to reject model hypotheses that are inconsistent with the data, or to estimate the unknown parameters. However, these tasks are complicated because experimental data are typically sparse, uncertain, and are frequently only available in form of qualitative if–then observations. ADMIT (Analysis, Design and Model Invalidation Toolbox) is a MatLabTM-based tool for guaranteed model invalidation, state and parameter estimation. The toolbox allows the integration of quantitative measurement data, a priori knowledge of parameters and states, and qualitative information on the dynamic or steady-state behavior. A constraint satisfaction problem is automatically generated and algorithms are implemented for solving the desired estimation, invalidation or analysis tasks. The implemented methods built on convex relaxation and optimization and therefore provide guaranteed estimation results and certificates for invalidity. Availability: ADMIT, tutorials and illustrative examples are available free of charge for non-commercial use at http://ifatwww.et.uni-magdeburg.de/syst/ADMIT/ Contact: stefan.streif@ovgu.de PMID:22451270

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

Jo, J.C.; Shin, W.K.; Choi, C.Y.

Transient heat transfer problems with phase changes (Stefan problems) occur in many engineering situations, including potential core melting and solidification during pressurized-water-reactor severe accidents, ablation of thermal shields, melting and solidification of alloys, and many others. This article addresses the numerical analysis of nonlinear transient heat transfer with melting or solidification. An effective and simple procedure is presented for the simulation of the motion of the boundary and the transient temperature field during the phase change process. To accomplish this purpose, an iterative implicit solution algorithm has been developed by employing the dual-reciprocity boundary-element method. The dual-reciprocity boundary-element approach providedmore » in this article is much simpler than the usual boundary-element method in applying a reciprocity principle and an available technique for dealing with the domain integral of the boundary element formulation simultaneously. In this article, attention is focused on two-dimensional melting (ablation)/solidification problems for simplicity. The accuracy and effectiveness of the present analysis method have been illustrated through comparisons of the calculation results of some examples of one-phase ablation/solidification problems with their known semianalytical or numerical solutions where available.« less

Theory of ice-skating

NASA Astrophysics Data System (ADS)

Le Berre, Martine; Pomeau, Yves

2015-10-01

Almost frictionless skating on ice relies on a thin layer of melted water insulating mechanically the blade of the skate from ice. Using the basic equations of fluid mechanics and Stefan law, we derive a set of two coupled equations for the thickness of the film and the length of contact, a length scale which cannot be taken as its value at rest. The analytical study of these equations allows to define a small a-dimensional parameter depending on the longitudinal coordinate which can be neglected everywhere except close to the contact points at the front and the end of the blade, where a boundary layer solution is given. This solution provides without any calculation the order of magnitude of the film thickness, and its dependence with respect to external parameters like the velocity and mass of the skater and the radius of profile and bite angle of the blade, in good agreement with the numerical study. Moreover this solution also shows that a lubricating water layer of macroscopic thickness always exists for standard values of ice skating data, contrary to what happens in the case of cavitation of droplets due to thermal heating (Leidenfrost effect).

Impact of Metal Droplets: A Numerical Approach to Solidification

NASA Astrophysics Data System (ADS)

Koldeweij, Robin; Mandamparambil, Rajesh; Lohse, Detlef

2016-11-01

Layer-wise deposition of material to produce complex products is a subject of increasing technological relevance. Subsequent deposition of droplets is one of the possible 3d printing technologies to accomplish this. The shape of the solidified droplet is crucial for product quality. We employ the volume-of-fluid method (in the form of the open-source code Gerris) to study liquid metal (in particular tin) droplet impact. Heat transfer has been implemented based on the enthalpy approach for the liquid-solid phase. Solidification is modeled by adding a sink term to the momentum equations, reducing Navier-Stokes to Darcy's law for high solid fraction. Good agreement is found when validating the results against experimental data. We then map out a phase diagram in which we distinguish between solidification behavior based on Weber and Stefan number. In an intermediate impact regime impact, solidification due to a retracting phase occurs. In this regime the maximum spreading diameter almost exclusively depends on Weber number. Droplet shape oscillations lead to a broad variation of the morphology of the solidified droplet and determine the final droplet height. TNO.

Modeling mass transfer and reaction of dilute solutes in a ternary phase system by the lattice Boltzmann method

NASA Astrophysics Data System (ADS)

Fu, Yu-Hang; Bai, Lin; Luo, Kai-Hong; Jin, Yong; Cheng, Yi

2017-04-01

In this work, we propose a general approach for modeling mass transfer and reaction of dilute solute(s) in incompressible three-phase flows by introducing a collision operator in lattice Boltzmann (LB) method. An LB equation was used to simulate the solute dynamics among three different fluids, in which the newly expanded collision operator was used to depict the interface behavior of dilute solute(s). The multiscale analysis showed that the presented model can recover the macroscopic transport equations derived from the Maxwell-Stefan equation for dilute solutes in three-phase systems. Compared with the analytical equation of state of solute and dynamic behavior, these results are proven to constitute a generalized framework to simulate solute distributions in three-phase flows, including compound soluble in one phase, compound adsorbed on single-interface, compound in two phases, and solute soluble in three phases. Moreover, numerical simulations of benchmark cases, such as phase decomposition, multilayered planar interfaces, and liquid lens, were performed to test the stability and efficiency of the model. Finally, the multiphase mass transfer and reaction in Janus droplet transport in a straight microchannel were well reproduced.

Droplet evaporation and combustion in a liquid-gas multiphase system

NASA Astrophysics Data System (ADS)

Muradoglu, Metin; Irfan, Muhammad

2017-11-01

Droplet evaporation and combustion in a liquid-gas multiphase system are studied computationally using a front-tracking method. One field formulation is used to solve the flow, energy and species equations with suitable jump conditions. Both phases are assumed to be incompressible; however, the divergence-free velocity field condition is modified to account for the phase change at the interface. Both temperature and species gradient driven phase change processes are simulated. Extensive validation studies are performed using the benchmark cases: The Stefan and the sucking interface problems, d2 law and wet bulb temperature comparison with the psychrometric chart values. The phase change solver is then extended to incorporate the burning process following the evaporation as a first step towards the development of a computational framework for spray combustion. We used detailed chemistry, variable transport properties and ideal gas behaviour for a n-heptane droplet combustion; the chemical kinetics being handled by the CHEMKIN. An operator-splitting approach is used to advance temperature and species mass fraction in time. The numerical results of the droplet burning rate, flame temperature and flame standoff ratio show good agreement with the experimental and previous numeric.

Molecular imaging of cannabis leaf tissue with MeV-SIMS method

NASA Astrophysics Data System (ADS)

Jenčič, Boštjan; Jeromel, Luka; Ogrinc Potočnik, Nina; Vogel-Mikuš, Katarina; Kovačec, Eva; Regvar, Marjana; Siketić, Zdravko; Vavpetič, Primož; Rupnik, Zdravko; Bučar, Klemen; Kelemen, Mitja; Kovač, Janez; Pelicon, Primož

2016-03-01

To broaden our analytical capabilities with molecular imaging in addition to the existing elemental imaging with micro-PIXE, a linear Time-Of-Flight mass spectrometer for MeV Secondary Ion Mass Spectrometry (MeV-SIMS) was constructed and added to the existing nuclear microprobe at the Jožef Stefan Institute. We measured absolute molecular yields and damage cross-section of reference materials, without significant alteration of the fragile biological samples during the duration of measurements in the mapping mode. We explored the analytical capability of the MeV-SIMS technique for chemical mapping of the plant tissue of medicinal cannabis leaves. A series of hand-cut plant tissue slices were prepared by standard shock-freezing and freeze-drying protocol and deposited on the Si wafer. We show the measured MeV-SIMS spectra showing a series of peaks in the mass area of cannabinoids, as well as their corresponding maps. The indicated molecular distributions at masses of 345.5 u and 359.4 u may be attributed to the protonated THCA and THCA-C4 acids, and show enhancement in the areas with opened trichome morphology.

Top-down proteomics for the analysis of proteolytic events - Methods, applications and perspectives.

PubMed

Tholey, Andreas; Becker, Alexander

2017-11-01

Mass spectrometry based proteomics is an indispensable tool for almost all research areas relevant for the understanding of proteolytic processing, ranging from the identification of substrates, products and cleavage sites up to the analysis of structural features influencing protease activity. The majority of methods for these studies are based on bottom-up proteomics performing analysis at peptide level. As this approach is characterized by a number of pitfalls, e.g. loss of molecular information, there is an ongoing effort to establish top-down proteomics, performing separation and MS analysis both at intact protein level. We briefly introduce major approaches of bottom-up proteomics used in the field of protease research and highlight the shortcomings of these methods. We then discuss the present state-of-the-art of top-down proteomics. Together with the discussion of known challenges we show the potential of this approach and present a number of successful applications of top-down proteomics in protease research. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John. Copyright © 2017 Elsevier B.V. All rights reserved.

Physics Meets Philosophy at the Planck Scale

NASA Astrophysics Data System (ADS)

Callender, Craig; Huggett, Nick

2001-04-01

Preface; 1. Introduction Craig Callendar and Nick Huggett; Part I. Theories of Quantum Gravity and their Philosophical Dimensions: 2. Spacetime and the philosophical challenge of quantum gravity Jeremy Butterfield and Christopher Isham; 3. Naive quantum gravity Steven Weinstein; 4. Quantum spacetime: what do we know? Carlo Rovelli; Part II. Strings: 5. Reflections on the fate of spacetime Edward Witten; 6. A philosopher looks at string theory Robert Weingard; 7. Black holes, dumb holes, and entropy William G. Unruh; Part III. Topological Quantum Field Theory: 8. Higher-dimensional algebra and Planck scale physics John C. Baez; Part IV. Quantum Gravity and the Interpretation of General Relativity: 9. On general covariance and best matching Julian B. Barbour; 10. Pre-Socratic quantum gravity Gordon Belot and John Earman; 11. The origin of the spacetime metric: Bell's 'Lorentzian Pedagogy' and its significance in general relativity Harvey R. Brown and Oliver Pooley; Part IV. Quantum Gravity and the Interpretation of Quantum Mechanics: 12. Quantum spacetime without observers: ontological clarity and the conceptual foundations of quantum gravity Sheldon Goldstein and Stefan Teufel; 13. On gravity's role in quantum state reduction Roger Penrose; 14. Why the quantum must yield to gravity Joy Christian.

Dynamic Model and Experimental Validation of a PEM Fuel Cell System

NASA Astrophysics Data System (ADS)

Nassif, Younane; Godoy, Emmanuel; Bethoux, Olivier; Roche, Ivan

Fuel cells are expected to become a challenging technology in terms of efficiency, and fitting the emission reduction schedules [Lemons, J. Power Sources, 29:251, 1] for the automotive application. Their fundamental component consists of two electrodes separated by a membrane. Fuel cells convert chemical energy into electrical energy while producing water and heat. To not disturb the transportation of the reactant gas, a proper membrane hydration needs to be maintained. Two different conditions can occur facing an inadequate water balance which decreases the performance of the stack. An insufficient removal of the accumulated water causes water flooding, decreasing reactant transport rate. Similarly, excessive water removal dries the membrane. To monitor the amount of water inside the cell, dynamic model based on the mass conservation principles and thermodynamic properties is developed in the form of nonlinear state space representation. Fick's law and Maxwell-Stefan model are used to describe multicomponent diffusion. Darcy's law is used to define the porous medium permeability. To demonstrate the accuracy of the proposed model, obtained results are compared with measured data at steady states operation mode. Investigation of the steady-state behavior is discussed in this paper.

Molecular simulation of steady-state evaporation and condensation in the presence of a non-condensable gas

NASA Astrophysics Data System (ADS)

Liang, Zhi; Keblinski, Pawel

2018-02-01

Using molecular dynamics simulations, we study evaporation and condensation of fluid Ar in the presence of a non-condensable Ne gas in a nanochannel. The evaporation and condensation are driven by the temperature difference, ΔTL, between the evaporating and condensing liquid surfaces. The steady-state evaporation and condensation fluxes (JMD) are also affected by the Ne concentration, ρNe, and the nanochannel length. We find that across a wide range of ΔTL and ρNe, JMD is in good agreement with the prediction from Stefan's law and from Schrage relationships. Furthermore, for ΔTL less than ˜20% of the absolute average temperature, we find that both steady-state heat and mass fluxes are proportional to ΔTL. This allows us to determine the interfacial resistance to the heat and mass transfer and compare it with the corresponding resistances in the gas phase. In this context, we derive an analytical expression for the effective thermal conductivity of the gas region in the nanochannel and the mass transport interfacial resistance equivalent length, i.e., the length of the nanochannel for which the resistance to the mass flow is the same as the interfacial resistance to the mass flow.

Heat Rejection from a Variable Conductance Heat Pipe Radiator Panel

NASA Technical Reports Server (NTRS)

Jaworske, D. A.; Gibson, M. A.; Hervol, D. S.

2012-01-01

A titanium-water heat pipe radiator having an innovative proprietary evaporator configuration was evaluated in a large vacuum chamber equipped with liquid nitrogen cooled cold walls. The radiator was manufactured by Advanced Cooling Technologies, Inc. (ACT), Lancaster, PA, and delivered as part of a Small Business Innovative Research effort. The radiator panel consisted of five titanium-water heat pipes operating as thermosyphons, sandwiched between two polymer matrix composite face sheets. The five variable conductance heat pipes were purposely charged with a small amount of non-condensable gas to control heat flow through the condenser. Heat rejection was evaluated over a wide range of inlet water temperature and flow conditions, and heat rejection was calculated in real-time utilizing a data acquisition system programmed with the Stefan-Boltzmann equation. Thermography through an infra-red transparent window identified heat flow across the panel. Under nominal operation, a maximum heat rejection value of over 2200 Watts was identified. The thermal vacuum evaluation of heat rejection provided critical information on understanding the radiator s performance, and in steady state and transient scenarios provided useful information for validating current thermal models in support of the Fission Power Systems Project.

Equilibrium properties of blackbody radiation with an ultraviolet energy cut-off

NASA Astrophysics Data System (ADS)

Mishra, Dheeraj Kumar; Chandra, Nitin; Vaibhav, Vinay

2017-10-01

We study various equilibrium thermodynamic properties of blackbody radiation (i.e. a photon gas) with an ultraviolet energy cut-off. We find that the energy density, specific heat etc. follow usual acoustic phonon dynamics as have been well studied by Debye. Other thermodynamic quantities like pressure, entropy etc. have also been calculated. The usual Stefan-Boltzmann law gets modified. We observe that the values of the thermodynamic quantities with the energy cut-off is lower than the corresponding values in the theory without any such scale. The phase-space measure is also expected to get modified for an exotic spacetime appearing at Planck scale, which in turn leads to the modification of Planck energy density distribution and the Wien's displacement law. We found that the non-perturbative nature of the thermodynamic quantities in the SR limit (for both unmodified and modified cases), due to nonanalyticity of the leading term, is a general feature of the theory accompanied with an ultraviolet energy cut-off. We have also discussed the possible modification in the case of Big Bang and the Stellar objects and have suggested a table top experiment for verification in effective low energy case.

ATLAS DBM Module Qualification

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

Soha, Aria; Gorisek, Andrej; Zavrtanik, Marko

2014-06-18

This is a technical scope of work (TSW) between the Fermi National Accelerator Laboratory (Fermilab) and the experimenters of Jozef Stefan Institute, CERN, and University of Toronto who have committed to participate in beam tests to be carried out during the 2014 Fermilab Test Beam Facility program. Chemical Vapour Deposition (CVD) diamond has a number of properties that make it attractive for high energy physics detector applications. Its large band-gap (5.5 eV) and large displacement energy (42 eV/atom) make it a material that is inherently radiation tolerant with very low leakage currents and high thermal conductivity. CVD diamond is beingmore » investigated by the RD42 Collaboration for use very close to LHC interaction regions, where the most extreme radiation conditions are found. This document builds on that work and proposes a highly spatially segmented diamond-based luminosity monitor to complement the time-segmented ATLAS Beam Conditions Monitor (BCM) so that, when Minimum Bias Trigger Scintillators (MTBS) and LUCID (LUminosity measurement using a Cherenkov Integrating Detector) have difficulty functioning, the ATLAS luminosity measurement is not compromised.« less

[Dr. Tadeusz Rakowiecki (July 26, 1878-April 6, 1965), physician, astronomer and writer--on the 25th anniversary of his death].

PubMed

Wiechowski, W

He decided to study medicine to be self-reliant and helpful for the society though he showed outstanding abilities to exact sciences, in particular mathematics. He was graduated at the Warsaw University in 1903 "cum eximia laude" in medicine. Apart from medicine he had disclosed interest in literature that was realized by many lectures and publications related to the famous and outstanding Polish writer Stefan Zeromski. Since 1930 Dr. Rakowiecki has started as self-taught astronomy studies becoming soon one of seven most eminent Polish astronomers. In the thirties there appeared his two-volume monography entitled "Drogi Planet i Komet" ("Motions of planets and comets") that has become the first fundamental Polish handbook of astronomy actual up to seventies. His scientific achievements based on higher mathematics included 20 important reports on astronomy and several monographs on mathematics. In 1930 he had refused several proposals to head University Chairs of Astronomy, among others in Lwów, due to modesty and his willingness to help and to serve his patients. He had been a demon for work, his rest after admission of patients were astronomy calculations, while when tired with the latters he became occupied with medicine.

Energy Content & Spectral Energy Representation of Wave Propagation in a Granular Chain

NASA Astrophysics Data System (ADS)

Shrivastava, Rohit; Luding, Stefan

2017-04-01

-signals, interpreting information from a Total Energy signal turned out to be much easier in comparison to displacement, velocity or acceleration signals of the wave, hence, indicating a better analysis method for wave propagation through granular materials. Increasing disorder decreases the Energy of higher frequency signals transmitted, but at the same time the energy of spatially localized high frequencies increases. Brian P. Lawney and Stefan Luding. Mass-disorder effects on the frequency filtering in one-dimensional discrete particle systems. AIP Conference Proceedings, 1542(1), 2013. Ibrahim Guven. Hydraulical and acoustical properties of porous sintered glass bead systems: experiments, theory and simulations (Doctoral dissertation). Rainer Tonn. Comparison of seven methods for the computation of Q. Physics of the Earth and Planetary Interiors, 55(3):259 - 268, 1989. Rohit Kumar Shrivastava and Stefan Luding.: Effect of Disorder on Bulk Sound Wave Speed : A Multiscale Spectral Analysis, Nonlin. Processes Geophys. Discuss., doi:10.5194/npg-2016-83, in review, 2017.

Controlling Particle Morphologies at Fluid Interfaces: Macro- and Micro- approaches

NASA Astrophysics Data System (ADS)

Beesabathuni, Shilpa Naidu

shapes such as ellipsoids, mushrooms, spherulites and discs. The final morphology of the wax particles is governed by the interfacial, inertial, viscous and thermal effects, which can be studied over a range of Weber, Capillary, Reynolds and Stefan numbers. A simplified Stefan problem for a spherical drop was solved. The time required to initiate a phase transition at the interface of the molten wax and water after impact was estimated and correlated with the drop deformation history and final wax particle shape to develop a capability to predict the shape. While the microfluidic synthesis approach offers precise control over morphology and functionality, large particle throughput is a limitation. The drop impact in a liquid medium emulsion approach is limited to crosslinking or heat sensitive materials but can be extended to large scale production for industrial applications. Both approaches are simple, robust and cost effective making them viable and attractive solutions for complex particle synthesis. The choice of the approach is dependent on considerations such as particle material, size, shape, throughput and end application.

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

Viktor K. Decyk

The UCLA work on this grant was to design and help implement an object-oriented version of the GTC code, which is written in Fortran90. The GTC code is the main global gyrokinetic code used in this project, and over the years multiple, incompatible versions have evolved. The reason for this effort is to allow multiple authors to work together on GTC and to simplify future enhancements to GTC. The effort was designed to proceed incrementally. Initially, an upper layer of classes (derived types and methods) was implemented which called the original GTC code 'under the hood.' The derived types pointedmore » to data in the original GTC code, and the methods called the original GTC subroutines. The original GTC code was modified only very slightly. This allowed one to define (and refine) a set of classes which described the important features of the GTC code in a new, more abstract way, with a minimum of implementation. Furthermore, classes could be added one at a time, and at the end of the each day, the code continued to work correctly. This work was done in close collaboration with Y. Nishimura from UC Irvine and Stefan Ethier from PPPL. Ten classes were ultimately defined and implemented: gyrokinetic and drift kinetic particles, scalar and vector fields, a mesh, jacobian, FLR, equilibrium, interpolation, and particles species descriptors. In the second state of this development, some of the scaffolding was removed. The constructors in the class objects now allocated the data and the array data in the original GTC code was removed. This isolated the components and now allowed multiple instantiations of the objects to be created, in particular, multiple ion species. Again, the work was done incrementally, one class at a time, so that the code was always working properly. This work was done in close collaboration with Y. Nishimura and W. Zhang from UC Irvine and Stefan Ethier from PPPL. The third stage of this work was to integrate the capabilities of the various

The Regulation of CH4 and N2O fluxes by Wetlands at Landscape Level

NASA Astrophysics Data System (ADS)

Soosaar, K.; Maddison, M.; Salm, J. O.; Järveoja, J.; Hansen, R.; Mander, Ü.

2012-04-01

: median values 4.2, 1.4, 1.1, and 0.9 kg N2O-N ha-1 y-1, respectively. In peatlands, median values of CH4-C were 85.2, 23.7, 0.07 and 0.12 kg ha-1 yr-1, and N2O-N -0.05, -0.01, 0.18 and 0.19 kg ha-1 yr-1, respectively. There were significantly higher emissions of N2O from abandoned and active peat mining areas, whereas CH4 emissions were significantly higher in natural and drained areas. We also found that the buffering capacity of long-term loaded riparian alder forests in agricultural landscapes will decrease over time, which calls for the careful management of these riparian forests. Mitsch, W.J, Zhang, L., Stefanik, K.C., Nahlik, A.M., Anderson, C.J., Bernal, B., Hernandez, M., Song, K. 2012. Creating wetlands: Primary succession, water quality changes, and self-design over 15 years. BioScience in press Zedler, JB. 2003. Wetlands at your service: reducing impacts of agriculture at the watershed scale. Front. Ecol. Environ., 1, pp. 65-72 Teiter, S., Mander, U. 2005. Emission of N2O, N2, CH4, and CO2 from constructed wetlands for wastewater treatment and from riparian buffer zones. Ecol. Eng., 25, pp. 528-541 Thiere, G., Stadmark, J., Weisner, SEB. 2011. Nitrogen retention versus methane emission: Environmental benefits and risks of large-scale wetland creation. Ecol. Eng., 37, pp. 6-15

[HUGO STEINHAUS--CO-FOUNDER OF THE LWÓW SCHOOL OF MATHEMATICS].

PubMed

Wócik, Wiesław

2014-01-01

The paper is dedicated to the presentation of professor Hugo Steinhaus--co-founder of the Lwów School of Mathematics. It is indicated that had it not been for the scholar, the founding and development of the Lwów School of Mathematics would have been almost impossible. The analyses focus on his undertakings during the Lvov period in the early 1920s and those events that preceded the founding of the school (namely Steinhaus's education at the Göttingen University, various meetings and gatherings, discussions, first fascinations and mathematical dissertations). This paper, however, does not look into the scientific output of Steinhaus, only presents his method of scientific work and highlights the strategy that he chose in order to create the scientific community. An attempt has been also made to justify the effectiveness of the adopted strategy by describing the scientific atmosphere of Lvov and intellectual potential of the students of the school. Steinhaus's activities in the 1930s will be only marginally presented with an impact on particularly interesting cooperation with the alumni of the Lwów School of Mathematics--Marek Kac, Stefan Kaczmarz, Paweł Nikliborec and scholars from other fields of science (as part of the process of the application of mathematics).

Analysis of close-contact melting with inner wall temperature variation in a horizontal cylindrical capsule

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

Saitoh, T.S.; Hoshi, Akira

1997-12-31

Melting and solidification of a phase change material (PCM) in a capsule is of practical importance in latent heat thermal energy storage (LHTES) systems which are considered to be very promising to reduce a peak demand of electricity in the summer season. Two melting modes are involved in melting in capsules. One is close-contact melting between the solid bulk and the capsule wall, and another is natural convection melting in the liquid region. In recent years, close-contact melting processes for a single enclosure have been solved using several numerical methods (e.g., Saitoh and Kato (1994)). However, there is no theoreticalmore » solution considering the inner wall temperature variation within cylindrical or spherical capsules. In this report close-contact melting heat transfer characteristics including melt flow in the liquid film under inner wall temperature distribution were analyzed and simple approximate equations are presented, which facilitates designing of the practical capsule bed LHTES systems. The effects of Stefan number and variable temperature profile etc. were clarified in detail. And the melting velocity of the solid bulk under various conditions was also studied theoretically. In addition, the effects of variable inner wall temperature on molten mass fraction were investigated.« less

Building a Low Cost Solar Oven: An Opportunity to Teach Thermodynamics

NASA Astrophysics Data System (ADS)

Nogueira, Ana

2014-03-01

We suggested building a solar oven using cardboard boxes, glass wool and metal plate as part of a school project permeated by the discussion of physical concepts. The main topics addressed are from the heat and thermodynamics areas, and for these themes we followed the standard books used in high school. We can work in a practical manner with the thermometer, along with the concept of temperature, measuring the temperature of the oven when cooking. To discuss how the oven works, we introduce the concept of heat as an energy flow of a body with a higher temperature to one with lower temperature. Threads as heat capacity and specific heat of a substance are introduced, also discussing the use of glass wool, which function is to prevent heat exchange from the oven's interior with the environment. It is possible to demonstrate the three forms of heat transfer using the solar oven, and how the greenhouse effect is harnessed. One can discuss topics such as electromagnetic radiation, black-body radiation and the Stefan-Boltzmann law. We surveyed the response curve of our oven and an estimate of its total solar energy absorption efficiency. The development of this project allows a good understanding of the operation principles of a solar oven. UNIMONTES.

Detailed in situ laser calibration of the infrared imaging video bolometer for the JT-60U tokamak

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

Parchamy, H.; Peterson, B. J.; Konoshima, S.

2006-10-15

The infrared imaging video bolometer (IRVB) in JT-60U includes a single graphite-coated gold foil with an effective area of 9x7 cm{sup 2} and a thickness of 2.5 {mu}m. The thermal images of the foil resulting from the plasma radiation are provided by an IR camera. The calibration technique of the IRVB gives confidence in the absolute levels of the measured values of the plasma radiation. The in situ calibration is carried out in order to obtain local foil properties such as the thermal diffusivity {kappa} and the product of the thermal conductivity k and the thickness t{sub f} of themore » foil. These quantities are necessary for solving the two-dimensional heat diffusion equation of the foil which is used in the experiments. These parameters are determined by comparing the measured temperature profiles (for kt{sub f}) and their decays (for {kappa}) with the corresponding results of a finite element model using the measured HeNe laser power profile as a known radiation power source. The infrared camera (Indigo/Omega) is calibrated by fitting the temperature rise of a heated plate to the resulting camera data using the Stefan-Boltzmann law.« less

Ivan Djaja (Jean Giaja)1 and the Belgrade School of Physiology

PubMed Central

Andjus, Pavle R.; Stojilkovic, Stanko S.; Cvijic, Gordana

2016-01-01

Summary The founder of physiology studies in the Balkans and the pioneer of research on hypothermia, Ivan Djaja (Jean Giaja) was born 1884 in L’Havre. Giaja gained his PhD at the Sorbonne in 1909. In 1910 he established the first Chair of Physiology in the Balkans and organized the first Serbian Institute for Physiology at the School of Philosophy of the University of Belgrade. He led this Institute for more than 40 subsequent years. His most notable papers were in the field of thermoregulation and bioenergetics. Djaja became member of the Serbian and Croatian academies of science and doctor honoris causa of Sorbonne. In 1952 for the seminal work on the behaviour of deep cooled warm blooded animals he becane associate member of the National Medical Academy in Paris. In 1955 the French Academy of Sciences elected him as associate member in place of deceased Sir Alexander Fleming. Djaja died in 1957 during a congress held in his honour. He left more than 200 scientific and other papers and the golden DaVincian credo “Nulla dies sine experimento”. His legacy was continued by several generations of researchers, the most prominent among them being Stefan Gelineo, Radoslav Andjus and Vojislav Petrović. PMID:21777022

A neutron track etch detector for electron linear accelerators in radiotherapy

PubMed Central

Vukovic, Branko; Faj, Dario; Poje, Marina; Varga, Maja; Radolic, Vanja; Miklavcic, Igor; Ivkovic, Ana; Planinic, Josip

2010-01-01

Background Electron linear accelerators in medical radiotherapy have replaced cobalt and caesium sources of radiation. However, medical accelerators with photon energies over 10 MeV generate undesired fast neutron contamination in a therapeutic X-ray photon beam. Photons with energies above 10 MeV can interact with the atomic nucleus of a high-Z material, of which the target and the head of an accelerator consist, and lead to the neutron ejection. Results and conclusions. Our neutron dosimeter, composed of the LR-115 track etch detector and boron foil BN-1 converter, was calibrated on thermal neutrons generated in the nuclear reactor of the Josef Stefan Institute (Slovenia), and applied to dosimetry of undesirable neutrons in photon radiotherapy by the linear accelerator 15 MV Siemens Mevatron. Having considered a high dependence of a cross-section between neutron and boron on neutron energy, and broad neutron spectrum in a photon beam, as well as outside the entrance door to maze of the Mevatron, we developed a method for determining the effective neutron detector response. A neutron dose rate in the photon beam was measured to be 1.96 Sv/h. Outside the Mevatron room the neutron dose rate was 0.62 μSv/h. PACS: 87.52. Ga; 87.53.St; 29.40.Wk. PMID:22933893

Thermal and Dynamic Properties of Volcanic Lava Inferred from Measurements on its Surface

NASA Astrophysics Data System (ADS)

Ismail-Zadeh, A.; Korotkii, A.; Kovtunov, D.; Tsepelev, I.; Melnik, O. E.

2015-12-01

Modern remote sensing technologies allow for detecting the absolute temperature at the surface of volcanic lava, and the heat flow could be then inferred from the Stefan-Boltzmann law. Is it possible to use these surface thermal data to constrain the thermal and dynamic conditions inside the lava? We propose a quantitative approach to reconstruct temperature and velocity in the steady-state volcanic lava flow from thermal observations at its surface. This problem is reduced to a combination of the direct and inverse problems of mass- and heat transport. Namely, using known conditions at the lava surface we determine the missing condition at the bottom of lava (the inverse problem) and then search for the physical properties of lava - temperature and flow velocity - inside the lava (the direct problem). Assuming that the lava rheology and the thermal conductivity are temperature-dependent, we determine the flow characteristics in the model domain using an adjoint method. We show that in the case of smooth input data (observations) the lava temperature and the flow velocity can be reconstructed with a high accuracy. The noise imposed on the smooth input data results in a less accurate solution, but still acceptable below some noise level.

The Quantum Focussing Conjecture and Quantum Null Energy Condition

NASA Astrophysics Data System (ADS)

Koeller, Jason

Evidence has been gathering over the decades that spacetime and gravity are best understood as emergent phenomenon, especially in the context of a unified description of quantum mechanics and gravity. The Quantum Focussing Conjecture (QFC) and Quantum Null Energy Condition (QNEC) are two recently-proposed relationships between entropy and geometry, and energy and entropy, respectively, which further strengthen this idea. In this thesis, we study the QFC and the QNEC. We prove the QNEC in a variety of contexts, including free field theories on Killing horizons, holographic theories on Killing horizons, and in more general curved spacetimes. We also consider the implications of the QFC and QNEC in asymptotically flat space, where they constrain the information content of gravitational radiation arriving at null infinity, and in AdS/CFT, where they are related to other semiclassical inequalities and properties of boundary-anchored extremal area surfaces. It is shown that the assumption of validity and vacuum-state saturation of the QNEC for regions of flat space defined by smooth cuts of null planes implies a local formula for the modular Hamiltonian of these regions. We also demonstrate that the QFC as originally conjectured can be violated in generic theories in d ≥ 5, which led the way to an improved formulation subsequently suggested by Stefan Leichenauer.

Strengthening Routine Data Systems to Track the HIV Epidemic and Guide the Response in Sub-Saharan Africa.

PubMed

Rice, Brian; Boulle, Andrew; Baral, Stefan; Egger, Matthias; Mee, Paul; Fearon, Elizabeth; Reniers, Georges; Todd, Jim; Schwarcz, Sandra; Weir, Sharon; Rutherford, George; Hargreaves, James

2018-04-03

The global HIV response has entered a new phase with the recommendation of treating all persons living with HIV with antiretroviral therapy, and with the goals of reducing new infections and AIDS-related deaths to fewer than 500,000 by 2020. This new phase has intensive data requirements that will need to utilize routine data collected through service delivery platforms to monitor progress toward these goals. With a focus on sub-Saharan African, we present the following priorities to improve the demand, supply, and use of routine HIV data: (1) strengthening patient-level HIV data systems that support continuity of clinical care and document sentinel events; (2) leveraging data from HIV testing programs; (3) using targeting data collection in communities and among clients; and (4) building capacity and promoting a culture of HIV data quality assessment and use. When fully leveraged, routine data can efficiently provide timely information at a local level to inform action, as well as provide information at scale with wide geographic coverage to strengthen estimation efforts. ©Brian Rice, Andrew Boulle, Stefan Baral, Matthias Egger, Paul Mee, Elizabeth Fearon, Georges Reniers, Jim Todd, Sandra Schwarcz, Sharon Weir, George Rutherford, James Hargreaves. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 03.04.2018.

Comparison of transient measurements of infrared radiation and stress waves for practical ablation monitoring during photorefractive keratectomy

NASA Astrophysics Data System (ADS)

Ishihara, Miya; Arai, Tsunenori; Kikuchi, Makoto; Nakano, Hironori; Kawauchi, Satoko; Obara, Minoru

1998-05-01

We compared infrared radiation measurement with stress wave measurement for real-time ablation monitoring during photorefractive keratectomy (PRK). We estimated temperature elevation which may be one of the most effective parameter for PRK monitoring, because the ablation mechanism is mainly attributed to thermal kinetics. The temperature elevation of ablated cornea was evaluated by the infrared radiation and the stress wave. The thermal radiation from irradiated cornea was detected by a MCT detector. The measured signal increased sharply just after the laser irradiation and decreased quasi- exponentially. We could calculate the temperature elevation by observed signal using Stefan-Boltzmann radiation law. In the case of the gelatin gel (15% wt) ablation in vitro, the temperature elevation was 97 deg. at 208 mJ/cm2 in the laser fluence. We also measured transient stress wave by the acoustic transducer which was made by polyvinylidene fluoride (PVDF) film. The temperature elevation could be calculated from the peak stress amplitude based on the short pulsed laser ablation theory. The good agreement on the temperature elevation was obtained between the infrared and the stress based estimations. Due to non-contact and non-invasive method, our infrared measurements for temperature elevation monitoring may be available to accomplish the feedback control on the PRK.

Numerical simulation of phase transition problems with explicit interface tracking

DOE PAGES

Hu, Yijing; Shi, Qiangqiang; de Almeida, Valmor F.; ...

2015-12-19

Phase change is ubiquitous in nature and industrial processes. Started from the Stefan problem, it is a topic with a long history in applied mathematics and sciences and continues to generate outstanding mathematical problems. For instance, the explicit tracking of the Gibbs dividing surface between phases is still a grand challenge. Our work has been motivated by such challenge and here we report on progress made in solving the governing equations of continuum transport in the presence of a moving interface by the front tracking method. The most pressing issue is the accounting of topological changes suffered by the interfacemore » between phases wherein break up and/or merge takes place. The underlying physics of topological changes require the incorporation of space-time subscales not at reach at the moment. Therefore we use heuristic geometrical arguments to reconnect phases in space. This heuristic approach provides new insight in various applications and it is extensible to include subscale physics and chemistry in the future. We demonstrate the method on applications such as simulating freezing, melting, dissolution, and precipitation. The later examples also include the coupling of the phase transition solution with the Navier-Stokes equations for the effect of flow convection.« less

General Relativity and Gravitation

NASA Astrophysics Data System (ADS)

Ashtekar, Abhay; Berger, Beverly; Isenberg, James; MacCallum, Malcolm

2015-07-01

Part I. Einstein's Triumph: 1. 100 years of general relativity George F. R. Ellis; 2. Was Einstein right? Clifford M. Will; 3. Cosmology David Wands, Misao Sasaki, Eiichiro Komatsu, Roy Maartens and Malcolm A. H. MacCallum; 4. Relativistic astrophysics Peter Schneider, Ramesh Narayan, Jeffrey E. McClintock, Peter Mészáros and Martin J. Rees; Part II. New Window on the Universe: 5. Receiving gravitational waves Beverly K. Berger, Karsten Danzmann, Gabriela Gonzalez, Andrea Lommen, Guido Mueller, Albrecht Rüdiger and William Joseph Weber; 6. Sources of gravitational waves. Theory and observations Alessandra Buonanno and B. S. Sathyaprakash; Part III. Gravity is Geometry, After All: 7. Probing strong field gravity through numerical simulations Frans Pretorius, Matthew W. Choptuik and Luis Lehner; 8. The initial value problem of general relativity and its implications Gregory J. Galloway, Pengzi Miao and Richard Schoen; 9. Global behavior of solutions to Einstein's equations Stefanos Aretakis, James Isenberg, Vincent Moncrief and Igor Rodnianski; Part IV. Beyond Einstein: 10. Quantum fields in curved space-times Stefan Hollands and Robert M. Wald; 11. From general relativity to quantum gravity Abhay Ashtekar, Martin Reuter and Carlo Rovelli; 12. Quantum gravity via unification Henriette Elvang and Gary T. Horowitz.

Shape-tunable wax microparticle synthesis via microfluidics and droplet impact

PubMed Central

Lee, Doojin; Beesabathuni, Shilpa N.; Shen, Amy Q.

2015-01-01

Spherical and non-spherical wax microparticles are generated by employing a facile two-step droplet microfluidic process which consists of the formation of molten wax microdroplets in a flow-focusing microchannel and their subsequent off-chip crystallization and deformation via microdroplet impingement on an immiscible liquid interface. Key parameters on the formation of molten wax microdroplets in a microfluidic channel are the viscosity of the molten wax and the interfacial tension between the dispersed and continuous fluids. A cursory phase diagram of wax morphology transition is depicted depending on the Capillary number and the Stefan number during the impact process. A combination of numerical simulation and analytical modeling is carried out to understand the physics underlying the deformation and crystallization process of the molten wax. The deformation of wax microdroplets is dominated by the viscous and thermal effects rather than the gravitational and buoyancy effects. Non-isothermal crystallization kinetics of the wax illustrates the time dependent thermal effects on the droplet deformation and crystallization. The work presented here will benefit those interested in the design and production criteria of soft non-spherical particles (i.e., alginate gels, wax, and polymer particles) with the aid of time and temperature mediated solidification and off-chip crosslinking. PMID:26697124

The inverse problem for definition of the shape of a molten contact bridge

NASA Astrophysics Data System (ADS)

Kharin, Stanislav N.; Sarsengeldin, Merey M.

2017-09-01

The paper presents the results of investigation of bridging phenomenon occurring at opening of electrical contacts. The mathematical model describing the dynamics of metal molten bridge takes into account the Thomson effect. It is based on the system of partial differential equations for temperature and electrical fields of the bridge in the domain containing two moving unknown boundaries. One of them is an interface between liquid and solid zones of the bridge and should be found by the solution of the corresponding Stefan problem. The second free boundary corresponds to the shape of the visible part of a bridge. Its definition is an inverse problem, for which solution it is necessary to find minimum of the energy consuming for the formation of the shape of a quasi-stationary bridge. Three components of this energy, namely surface tension, pinch effect and gravitation, are defined by the functional which minimum gives the required shape of the bridge. The solution of corresponding variation problem is found by the reduction of the problem to the solution of the system of ordinary differential equations. Calculated values of the voltage of the bridge rupture for various metals are in a good agreement with the experimental data. The criteria responsible for the mechanism of molten bridge rupture are introduced in the paper.

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

Jain, Richa Naja, E-mail: ltprichanaja@gmail.com; Chakraborty, Brahmananda; Ramaniah, Lavanya M.

In this work our main objective is to compute Dynamical correlations, Onsager coefficients and Maxwell-Stefan (MS) diffusivities for molten salt LiF-KF mixture at various thermodynamic states through Green–Kubo formalism for the first time. The equilibrium molecular dynamics (MD) simulations were performed using BHM potential for LiF–KF mixture. The velocity autocorrelations functions involving Li ions reflect the endurance of cage dynamics or backscattering with temperature. The magnitude of Onsager coefficients for all pairs increases with increase in temperature. Interestingly most of the Onsager coefficients has almost maximum magnitude at the eutectic composition indicating the most dynamic character of the eutectic mixture.more » MS diffusivity hence diffusion for all ion pairs increases in the system with increasing temperature. Smooth variation of the diffusivity values denies any network formation in the mixture. Also, the striking feature is the noticeable concentration dependence of MS diffusivity between cation-cation pair, Đ{sub Li-K} which remains negative for most of the concentration range but changes sign to become positive for higher LiF concentration. The negative MS diffusivity is acceptable as it satisfies the non-negative entropy constraint governed by 2{sup nd} law of thermodynamics. This high diffusivity also vouches the candidature of molten salt as a coolant.« less

The plasma membrane: Penultimate regulator of ADAM sheddase function.

PubMed

Reiss, Karina; Bhakdi, Sucharit

2017-11-01

ADAM10 and ADAM17 are the best characterized members of the ADAM (A Disintegrin and Metalloproteinase) - family of transmembrane proteases. Both are involved diverse physiological and pathophysiological processes. ADAMs are known to be regulated by posttranslational mechanisms. However, emerging evidence indicates that the plasma membrane with its unique dynamic properties may additionally play an important role in controlling sheddase function. Membrane events that could contribute to regulation of ADAM-function are summarized. Surface expression of peptidolytic activity should be differentiated from ADAM-sheddase function since the latter additionally requires that the protease finds its substrate in the lipid bilayer. We propose that this is achieved through horizontal and vertical reorganization of membrane nanoarchitecture coordinately occurring at the sites of sheddase activation. Reshuffling of nanodomains thereby guides traffic of enzyme and substrate to each other. For ADAM17 phosphatidylserine exposure is required to then induce its shedding function. The novel concept that physicochemical properties of the lipid bilayer govern the action of ADAM-proteases may be extendable to other functional proteins that act at the cell surface. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John. Copyright © 2017. Published by Elsevier B.V.

Ivrea mantle wedge and arc of the Western Alps (I): Geophysical evidence for the deep structure

NASA Astrophysics Data System (ADS)

Kissling, Edi; Schmid, Stefan M.; Diehl, Tobias

2017-04-01

The construction of five crustal-scale profiles across the Western Alps and the Ivrea mantle wedge integrates up-to-date geological and geophysical information and reveals important along strike changes in the overall structure of the crust of the Western Alpine arc (Schmid et al. 2017). The 3D crustal model of the Western Alps represented by these cross sections is based on recent P-velocity local earthquake tomography that compliments the previously existing wealth of geophysical information about lithosphere structure in the region. As part of Adria mantle lithosphere exhibiting strong upward bending toward the plate boundary along the inner arc of the Western Alps, the well-known Ivrea body plays a crucial role in our tectonic model. Until recently, however, the detailed 3D geometry of this key structure was only poorly constrained. In this study we present a review of the many seismic data in the region and we document the construction of our 3D lithosphere model by principles of multidisciplinary seismic tomography. Reference: Stefan M. Schmid, Edi Kissling, Douwe J.J. van Hinsbergen, Giancarlo Molli (2017). Ivrea mantle wedge and arc of the Western Alps (2): Kinematic evolution of the Alps-Apennines orogenic system. Abstract Volume EGU 2017.

Physical vapor transport of mercurous chloride under a nonlinear thermal profile

NASA Technical Reports Server (NTRS)

Mennetrier, Christophe; Duval, Walter M. B.; Singh, Narsingh B.

1992-01-01

Our study investigates numerically the flow field characteristics during the growth of mercurous chloride (Hg2Cl2) crystals in a rectangular ampoule under terrestrial and microgravity conditions for a nonlinear thermal gradient. With a residual gas lighter than the nutrient, the solutal Grashof number is dominant. We observe that in tilted configurations, when solutal convection is dominant, the maximum transport rate occurs at approximately 40 percent. For the vertical configurations, we were able to obtain solutions only for the cases either below the critical Rayleigh numbers or the stabilized configurations. The total mass flux decreases exponentially with an increase of pressure of residual gas, but it increases following a power law with the temperature difference driving the transport. The nonlinear thermal gradient appears to destabilize the flow field when thermal convection is dominant for both vertical top-heated and bottom-heated configurations. However, when the solutal Grashof number is dominant, the density gradient resulting from the solutal gradient appears to stabilize the flow for the bottom-heated configuration. The flow field for the top-heated configuration is destabilized for high Grashof numbers. The microgravity environment provides a means for lowering convection. For gravity levels of 10(exp -3) g(0) or less, the Stefan wind drives the flow, and no recirculating cell is predicted.

Thermal Physical Property-Based Fusion of Geostationary Meteorological Satellite Visible and Infrared Channel Images

PubMed Central

Han, Lei; Shi, Lu; Yang, Yiling; Song, Dalei

2014-01-01

Geostationary meteorological satellite infrared (IR) channel data contain important spectral information for meteorological research and applications, but their spatial resolution is relatively low. The objective of this study is to obtain higher-resolution IR images. One common method of increasing resolution fuses the IR data with high-resolution visible (VIS) channel data. However, most existing image fusion methods focus only on visual performance, and often fail to take into account the thermal physical properties of the IR images. As a result, spectral distortion occurs frequently. To tackle this problem, we propose a thermal physical properties-based correction method for fusing geostationary meteorological satellite IR and VIS images. In our two-step process, the high-resolution structural features of the VIS image are first extracted and incorporated into the IR image using regular multi-resolution fusion approach, such as the multiwavelet analysis. This step significantly increases the visual details in the IR image, but fake thermal information may be included. Next, the Stefan-Boltzmann Law is applied to correct the distortion, to retain or recover the thermal infrared nature of the fused image. The results of both the qualitative and quantitative evaluation demonstrate that the proposed physical correction method both improves the spatial resolution and preserves the infrared thermal properties. PMID:24919017

Thermal physical property-based fusion of geostationary meteorological satellite visible and infrared channel images.

PubMed

Han, Lei; Shi, Lu; Yang, Yiling; Song, Dalei

2014-06-10

Geostationary meteorological satellite infrared (IR) channel data contain important spectral information for meteorological research and applications, but their spatial resolution is relatively low. The objective of this study is to obtain higher-resolution IR images. One common method of increasing resolution fuses the IR data with high-resolution visible (VIS) channel data. However, most existing image fusion methods focus only on visual performance, and often fail to take into account the thermal physical properties of the IR images. As a result, spectral distortion occurs frequently. To tackle this problem, we propose a thermal physical properties-based correction method for fusing geostationary meteorological satellite IR and VIS images. In our two-step process, the high-resolution structural features of the VIS image are first extracted and incorporated into the IR image using regular multi-resolution fusion approach, such as the multiwavelet analysis. This step significantly increases the visual details in the IR image, but fake thermal information may be included. Next, the Stefan-Boltzmann Law is applied to correct the distortion, to retain or recover the thermal infrared nature of the fused image. The results of both the qualitative and quantitative evaluation demonstrate that the proposed physical correction method both improves the spatial resolution and preserves the infrared thermal properties.

A Role for New Brain Magnetic Resonance Imaging Modalities in Daily Clinical Practice: Protocol of the Prediction of Cognitive Recovery After Stroke (PROCRAS) Study.

PubMed

Aben, Hugo P; Reijmer, Yael D; Visser-Meily, Johanna Ma; Spikman, Jacoba M; de Bresser, Jeroen; Biessels, Geert Jan; de Kort, Paul Lm

2018-05-28

Cognitive impairment is common after acute ischemic stroke, affecting up to 75% of the patients. About half of the patients will show recovery, whereas the others will remain cognitively impaired or deteriorate. It is difficult to predict these different cognitive outcomes. The objective of this study is to investigate whether diffusion tensor imaging-based measures of brain connectivity predict cognitive recovery after 1 year, in addition to patient characteristics and stroke severity. A specific premise of the Prediction of Cognitive Recovery After Stroke (PROCRAS) study is that it is conducted in a daily practice setting. The PROCRAS study is a prospective, mono-center cohort study conducted in a large teaching hospital in the Netherlands. A total of 350 patients suffering from an ischemic stroke who screen positive for cognitive impairment on the Montreal Cognitive Assessment (MoCA<26) in the acute stage will undergo a 3Tesla-Magnetic Resonance Imaging (3T-MRI) with a diffusion-weighted sequence and a neuropsychological assessment. Patients will be classified as being unimpaired, as having a mild vascular cognitive disorder, or as having a major vascular cognitive disorder. One year after stroke, patients will undergo follow-up neuropsychological assessment. The primary endpoint is recovery of cognitive function 1 year after stroke in patients with a confirmed poststroke cognitive disorder. The secondary endpoint is deterioration of cognitive function in the first year after stroke. The study is already ongoing for 1.5 years, and thus far, 252 patients have provided written informed consent. Final results are expected in June 2019. The PROCRAS study will show the additional predictive value of diffusion tensor imaging-based measures of brain connectivity for cognitive outcome at 1 year in patients with a poststroke cognitive disorder in a daily clinical practice setting. RR1-10.2196/9431. ©Hugo P Aben, Yael D Reijmer, Johanna MA Visser-Meily, Jacoba M Spikman

PREFACE: Proceedings Symposium G of E-MRS Spring Meeting on Fundamentals and Technology of Multifunctional Oxide Thin Films

NASA Astrophysics Data System (ADS)

2010-07-01

field was highlighted by P Günter. Many contributions were devoted to processing techniques, showing the increasing importance of CVD techniques to deposit for instance perovskite thin films (G Malandrino). Nevertheless, stunning results were obtained by a sophisticated MBE tool allowing for precise compositional control of individual oxide monolayers and thus enabling High-Tc supraconductivity in individual monolayers to be addressed (I Bosovic). Oxides do not only gleam with giant dielectric properties, giant electronic conduction (superconductivity), there is also a giant electro-caloric effect, as explained by Z Kutnjak. The symposium could take advantage of the EU projects NUOTO and CAMELIA that organized a joint session on giant K dielectrics to present their project results to the scientific and industrial community. The symposium organizers Paul Muralt, EPFL, Lausanne, Switzerland Marija Kosec, Josef Stefan Institute, Ljubljana, Slovenia Vito Raineri, IMM-CNR, Catania, Italy Sebastiano Ravesi, STMicroelectronics, Catania, Italy Scientific Committee Robert Blinc (Josef Stefan Inst., Slovenia) Wolfgang Kleemann (Univ. Duisburg, Germany) Raffaella Lo Nigro (IMM-CNR, Italy) Ian M Reaney (Univ. Sheffield, Great Britain) T Metzger (EPCOS, Germany) Rainer Waser (TH Aachen, Germany)

Evaporation enhancement in soils: a critical review

NASA Astrophysics Data System (ADS)

Rutten, Martine; van de Giesen, Nick

2015-04-01

Temperature gradients in the top layer of the soil are, especially during the daytime, steeper than would be expected if thermal conduction was the primary heat transfer mechanism. Evaporation seems to have significant influence on the soil heat budget. Only part of the surface soil heat flux is conducted downwards, increasing the soil temperatures, and part is used for evaporation, acting as a sink to the soil heat budget. For moist soils, the evaporation is limited by the transport of water molecules to the surface. The classical view is that water vapor is transported from the evaporation front to the surface by diffusion. Diffusion is mixing due to the random movement of molecules resulting in flattening concentration gradients. In soil, the diffusive vapor flux and the resulting latent heat flux are generally small. We found that transport enhancement is necessary in order to sustain vapor fluxes that are large enough to sustain latent heat fluxes, as well as being large enough to explain the observed temperature gradients. Enhancement of vapor diffusion is a known phenomenon, subject to debate on the explanations of underlying mechanism. In an extensive literature review on vapor enhancement in soils, the plausibility of various mechanisms was assessed. We reviewed mechanisms based on (combinations of) diffusive, viscous, buoyant, capillary and external pressure forces including: thermodiffusion, dispersion, Stefan's flow, Knudsen diffusion, liquid island effect, hydraulic lift, free convection, double diffusive convection and forced convection. The analysis of the order of magnitude of the mechanisms based on first principles clearly distinguished between plausible and implausible mechanisms. Thermodiffusion, Stefan's flow, Knudsen effects, liquid islands do not significantly contribute to enhanced evaporation. Double diffusive convection seemed unlikely due to lack of experimental evidence, but could not be completely excluded from the list of potential

Combustion of Interacting Droplet Arrays in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Dietrich, Daniel L.; Struk, Peter M.; Kitano, Kunihiro; Ikeda, Koji; Honma, Senji

1997-01-01

This research program involves the study of single droplets and linear arrays of droplets in weakly-buoyant and non-bouyant environments. The primary purpose of the single droplet work was to (1) provide a data base from which to compare droplet array results and (2) to correlate the effects of buoyancy on flame shape. Traditionally convective effects in droplet combustion are represented in terms of the Reynolds number, Re, for forced convection and the Grashof number, Gr, for natural convection. Typically, corrections to the burning rate constant for convective effects are written in terms of Re or Gr(exp 1). The Stefan velocity is not included in these correlations, even though from purely physical reasons, one would expect it to be important, especially at higher burning rates. The flame distortion due to convective effects is less documented quantitatively. Kumagai and Isoda do predict flame shape in natural and forced convective flow fields. Their focus, however, was to predict the actual flame dimensions. Law and co-workers used reduced pressure, high oxidizer ambients to obtain spherical flames. This implies that buoyant flows were reduced at the low pressures, as indicated by a very small Grashof number. Ross et al, however, using scaling arguments showed that reducing the pressure does not have a large effect on the magnitude of the buoyant velocity. Struk et al showed elongated flame shapes during simulated (porous sphere) droplet combustion. The elongation of the flames was due to residual gravity levels aboard the reduced gravity aircraft on which the experiments were conducted. These flame shapes, as well as some data from the literature were interpreted based on a dimensionless grouping called the sphericity parameter, Sp. Sp is the ratio of a characteristic computed buoyant velocity to the Stefan velocity at the flame front. One purpose of the droplet arrays work is to extend the database and theories that exist for single droplets into the regime

Development of psychotherapy as a method of mental disorders treatment at the Jagiellonian University and in Kraków before World War I.

PubMed

Dembińska, Edyta; Rutkowski, Krzysztof

2016-01-01

This article presents the origins of Polish psychotherapy with a special focus on psychotherapy development in Krakow and at the Jagiellonian University. The history of Krakow psychotherapy starts with the foundation of the Psychiatry and Neuropathology Clinic of the Jagiellonian University in 1905. Doctors working in the Department of psychotherapy developed their skills through contacts with the Zurich University Psychiatric Clinic Burgholzli. At the same time psychotherapy, and psychoanalysis in particular, were raising more and more interest in Poland. The most dynamic development of psychoanalysis reflected in the number of scientific publications, occurs in the years leading to the outbreak of War World I. This article presents brief portraits of the first Polish psychoanalysts ( Ludwik Jekels, Herman Nunberg, Ludwika Karpińska, Stefan Borowiecki, Jan Nelken, Kraol de Beaurain). Many of them worked in Psychiatry and Neuropathology Clinic of the Jagiellonian University. Their scientific achievements and contribution to the development of the international psychoanalytic movement are described, as well as relationships with leading psychoanalysts of this period (Freud, Jung). With the outbreak of World War I the research on and treatment of war neurosis was initiated in the Psychiatry and Neuropathology Clinic. Professor Piltz, the director of the clinic, together with his assistants (Borowiecki, de Beuarain, Artwiński) devised a unique in European psychiatry and highly efficient method of post-traumatic disorders treatment, in which psychotherapy was of key importance.

Ergonomic evaluation of workload by milk production - a bibliometric analysis.

PubMed

de Oliveira, Claudilaine Caldas; Pereira Moro, Antônio Renato; Ulbricht, Leandra; Belinelli, Marjorie; de Souza, Gilberto F M; Gabriel, Michele; Zattar, Izabel Cristina

2017-09-21

The purpose of this study was to select in a structured manner the relevant articles with scientific recognition, and simultaneously identify the characteristics of these publications that may scientifically enrich the theme in a portfolio of papers. The theme involves ergonomics in milk production as a criterion for evaluating and improving organizational performance in the milking sector. The study used ProKnow-C as a theoretical instrument for intervention. The main results show: i) a bibliographic portfolio of 18 items aligned with the view adopted by researchers which served as a theoretical framework for this research; ii) The article entitled "Wrist positions and movements as possible risk factors during machine milking", by Marianne Stål, Gert-Åke Hansson and Ulrich Moritz in 1999 and published in the Journal of Applied Ergonomics presented the highest scientific recognition, iii) the authors highlighted in the bibliographic portfolio or in its references researching the subject are Gert-Åke Hansson, Marianne Stål and Stefan Pinzke, and iv) the International Journal of Industrial Ergonomics shows the highest number of scientific articles in the bibliographic portfolio. The studies selected using the methodology indicate research in ergonomics focused on the production of milk in rural areas, specifically in the milking sector, are generally related to the health and safety of the workers.

Getting in shape: molten wax drop deformation and solidification at an immiscible liquid interface.

PubMed

Beesabathuni, Shilpa N; Lindberg, Seth E; Caggioni, Marco; Wesner, Chris; Shen, Amy Q

2015-05-01

The controlled production of non-spherical shaped particles is important for many applications such as food processing, consumer goods, adsorbents, drug delivery, and optical sensing. In this paper, we investigated the deformation and simultaneous solidification of millimeter size molten wax drops as they impacted an immiscible liquid interface of higher density. By varying initial temperature and viscoelasticity of the molten drop, drop size, impact velocity, viscosity and temperature of the bath fluid, and the interfacial tension between the molten wax and bath fluid, spherical molten wax drops impinged on a cooling water bath and were arrested into non-spherical solidified particles in the form of ellipsoid, mushroom, disc, and flake-like shapes. We constructed cursory phase diagrams for the various particle shapes generated over a range of Weber, Capillary, Reynolds, and Stefan numbers, governed by the interfacial, inertial, viscous, and thermal effects. We solved a simplified heat transfer problem to estimate the time required to initiate the solidification at the interface of a spherical molten wax droplet and cooling aqueous bath after impact. By correlating this time with the molten wax drop deformation history captured from high speed imaging experiments, we elucidate the delicate balance of interfacial, inertial, viscous, and thermal forces that determine the final morphology of wax particles. Copyright © 2015 Elsevier Inc. All rights reserved.

Representations of eyeglasses on Gothic winged altars in Austria.

PubMed

Daxecker, F

1997-01-01

The oldest representation of eyeglasses in the German-speaking area is found on the altar of Tyrol Castle in the Museum Ferdinandeum in Innsbruck, Tyrol, on an altarpiece depicting the death of the Virgin Mary (1370-1372). Other representations of eyeglasses are found in Klosterneuburg, Lower Austria, Albrechtsaltar, collegiate collection, death of the Virgin (1439); St. Lorenzen ob Murau, daughter church St. Lorenzen, Styria, Katharinenaltar, Disputation (1455-1460); Pettau (Ptuj), Pokrajinjski Muzej, Slovenia (then belonging to the archbishopric of Salzburg), Conrad Laib, St. Bernardine of Siena with a spectacle case (1460-1465); on two altars by Michael Pacher: Pharisee, Gries near Bolzano (1471-1475), apostle mourning over the death of the Virgin Mary, and St. Luke, St. Wolfgang in Salzkammergut (1481); St. Florian, Upper Austria, collegiate collection, altar of the provost Leonhard Riesenschmid of St. Florian, death of the Virgin (1487); museum of Wilten monastery, Innsbruck, Ludwig Konraiter, St. Ottilie with reading stones and death of the Virgin Mary with reading apostle (1485-1490); Austrian Gallery Belvedere, Vienna, Master of Grossgmain, St. Augustine (1498); Austrian Gallery Belvedere, Vienna, Master of Mondsee, St. Augustine (1490-1500); Diocesan museum Graz, Styria, altar of Hirschegg, death of the Virgin (1503); Krenstetten, Lower Austria, Stefan-Altar, Disputation (1500-1520); Museum Ferdinandeum, Innsbruck, Matheis Stöberl, Jesus and the scribes with a spectacle case (early 16th century).

The boundary integral theory for slow and rapid curved solid/liquid interfaces propagating into binary systems

NASA Astrophysics Data System (ADS)

Galenko, Peter K.; Alexandrov, Dmitri V.; Titova, Ekaterina A.

2018-01-01

The boundary integral method for propagating solid/liquid interfaces is detailed with allowance for the thermo-solutal Stefan-type models. Two types of mass transfer mechanisms corresponding to the local equilibrium (parabolic-type equation) and local non-equilibrium (hyperbolic-type equation) solidification conditions are considered. A unified integro-differential equation for the curved interface is derived. This equation contains the steady-state conditions of solidification as a special case. The boundary integral analysis demonstrates how to derive the quasi-stationary Ivantsov and Horvay-Cahn solutions that, respectively, define the paraboloidal and elliptical crystal shapes. In the limit of highest Péclet numbers, these quasi-stationary solutions describe the shape of the area around the dendritic tip in the form of a smooth sphere in the isotropic case and a deformed sphere along the directions of anisotropy strength in the anisotropic case. A thermo-solutal selection criterion of the quasi-stationary growth mode of dendrites which includes arbitrary Péclet numbers is obtained. To demonstrate the selection of patterns, computational modelling of the quasi-stationary growth of crystals in a binary mixture is carried out. The modelling makes it possible to obtain selected structures in the form of dendritic, fractal or planar crystals. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

Boundary conditions for a one-sided numerical model of evaporative instabilities in sessile drops of ethanol on heated substrates

NASA Astrophysics Data System (ADS)

Semenov, Sergey; Carle, Florian; Medale, Marc; Brutin, David

2017-12-01

The work is focused on obtaining boundary conditions for a one-sided numerical model of thermoconvective instabilities in evaporating pinned sessile droplets of ethanol on heated substrates. In the one-sided model, appropriate boundary conditions for heat and mass transfer equations are required at the droplet surface. Such boundary conditions are obtained in the present work based on a derived semiempirical theoretical formula for the total droplet's evaporation rate, and on a two-parametric nonisothermal approximation of the local evaporation flux. The main purpose of these boundary conditions is to be applied in future three-dimensional (3D) one-sided numerical models in order to save a lot of computational time and resources by solving equations only in the droplet domain. Two parameters, needed for the nonisothermal approximation of the local evaporation flux, are obtained by fitting computational results of a 2D two-sided numerical model. Such model is validated here against parabolic flight experiments and the theoretical value of the total evaporation rate. This study combines theoretical, experimental, and computational approaches in convective evaporation of sessile droplets. The influence of the gravity level on evaporation rate and contributions of different mechanisms of vapor transport (diffusion, Stefan flow, natural convection) are shown. The qualitative difference (in terms of developing thermoconvective instabilities) between steady-state and unsteady numerical approaches is demonstrated.

Design and optimization of anode flow field of a large proton exchange membrane fuel cell for high hydrogen utilization

NASA Astrophysics Data System (ADS)

Yesilyurt, Serhat; Rizwandi, Omid

2016-11-01

We developed a CFD model of the anode flow field of a large proton exchange membrane fuel cell that operates under the ultra-low stoichiometric (ULS) flow conditions which intend to improve the disadvantages of the dead-ended operation such as severe voltage transient and carbon corrosion. Very small exit velocity must be high enough to remove accumulated nitrogen, and must be low enough to retain hydrogen in the active area. Stokes equations are used to model the flow distribution in the flow field, Maxwell-Stefan equations are used to model the transport of the species, and a voltage model is developed to model the reactions kinetics. Uniformity of the distribution of hydrogen concentration is quantified as the normalized area of the region in which the hydrogen mole fraction remains above a certain level, such as 0.9. Geometry of the anode flow field is modified to obtain optimal configuration; the number of baffles at the inlet, width of the gaps between baffles, width of the side gaps, and length of the central baffle are used as design variables. In the final design, the hydrogen-depleted region is less than 0.2% and the hydrogen utilization is above 99%. This work was supported by The Scientific and Technolo-gical Research Council of Turkey, TUBITAK-213M023.

Mathematical estimation of melt depth in conduction mode of laser spot remelting process

NASA Astrophysics Data System (ADS)

Hadi, Iraj

2012-12-01

A one-dimensional mathematical model based on the front tracking method was developed to predict the melt depth as a function of internal and external parameters of laser spot remelting process in conduction mode. Power density, pulse duration, and thermophysical properties of material including thermal diffusivity, melting point, latent heat, and absorption coefficient have been taken into account in the model of this article. By comparing the theoretical results and experimental welding data of commercial pure nickel and titanium plates, the validity of the developed model was examined. Comparison shows a reasonably good agreement between the theory and experiment. For the sake of simplicity, a graphical technique was presented to obtain the melt depth of various materials at any arbitrary amount of power density and pulse duration. In the graphical technique, two dimensionless constants including the Stefan number (Ste) and an introduced constant named laser power factor (LPF) are used. Indeed, all of the internal and external parameters have been gathered in LPF. The effect of power density and pulse duration on the variation of melt depth for different materials such as aluminum, copper, and stainless steel were investigated. Additionally, appropriate expressions were extracted to describe the minimum power density and time to reach melting point in terms of process parameters. A simple expression is also extracted to estimate the thickness of mushy zone for alloys.

IJS procedure for RELAP5 to TRACE input model conversion using SNAP

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

Prosek, A.; Berar, O. A.

2012-07-01

The TRAC/RELAP Advanced Computational Engine (TRACE) advanced, best-estimate reactor systems code developed by the U.S. Nuclear Regulatory Commission comes with a graphical user interface called Symbolic Nuclear Analysis Package (SNAP). Much of efforts have been done in the past to develop the RELAP5 input decks. The purpose of this study is to demonstrate the Institut 'Josef Stefan' (IJS) conversion procedure from RELAP5 to TRACE input model of BETHSY facility. The IJS conversion procedure consists of eleven steps and is based on the use of SNAP. For calculations of the selected BETHSY 6.2TC test the RELAP5/MOD3.3 Patch 4 and TRACE V5.0more » Patch 1 were used. The selected BETHSY 6.2TC test was 15.24 cm equivalent diameter horizontal cold leg break in the reference pressurized water reactor without high pressure and low pressure safety injection. The application of the IJS procedure for conversion of BETHSY input model showed that it is important to perform the steps in proper sequence. The overall calculated results obtained with TRACE using the converted RELAP5 model were close to experimental data and comparable to RELAP5/MOD3.3 calculations. Therefore it can be concluded, that proposed IJS conversion procedure was successfully demonstrated on the BETHSY integral test facility input model. (authors)« less

A Transition in the Cumulative Reaction Rate of Two Species Diffusion with Bimolecular Reaction

NASA Astrophysics Data System (ADS)

Rajaram, Harihar; Arshadi, Masoud

2015-04-01

Diffusion and bimolecular reaction between two initially separated reacting species is a prototypical small-scale description of reaction induced by transverse mixing. It is also relevant to diffusion controlled transport regimes as encountered in low-permeability matrix blocks in fractured media. In previous work, the reaction-diffusion problem has been analyzed as a Stefan problem involving a distinct moving boundary (reaction front), which predicts that front motion scales as √t, and the cumulative reaction rate scales as 1/√t-. We present a general non-dimensionalization of the problem and a perturbation analysis to show that there is an early time regime where the cumulative reaction rate scales as √t- rather than 1/√t. The duration of this early time regime (where the cumulative rate is kinetically rather than diffusion controlled) depends on the rate parameter, in a manner that is consistently predicted by our non-dimensionalization. We also present results on the scaling of the reaction front width. We present numerical simulations in homogeneous and heterogeneous porous media to demonstrate the limited influence of heterogeneity on the behavior of the reaction-diffusion system. We illustrate applications to the practical problem of in-situ chemical oxidation of TCE and PCE by permanganate, which is employed to remediate contaminated sites where the DNAPLs are largely dissolved in the rock matrix.

Medicine at the crossroads. Part II. Summary of completed project

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

NONE

1998-05-01

Medicine at the crossroads (a.k.a. The Future of Medicine) is an 8-part series of one-hour documentaries which examines the scientific and social forces that have shaped the practice of medicine around the world. The series was developed and produced over a five-year period and in eleven countries. Among the major issues examined in the series are the education of medical practitioners and the communication of medical issues. The series also considers the dilemmas of modern medicine, including the treatment of the elderly and the dying, the myth of the quick fix in the face of chronic and incurable diseases suchmore » as HIV, and the far-reaching implications of genetic treatments. Finally, the series examines the global progress made in medical research and application, as well as the questions remaining to be answered. These include not only scientific treatment, but accessibility and other critical topics affecting the overall success of medical advances. Medicine at the crossroads is a co-production of Thirteen/WNET and BBC-TV in association with Television Espafiola SA (RTVE) and the Australian Broadcasting Corporation. Stefan Moore of Thirteen/WNET and Martin Freeth of BBC-TV are series producers. George Page is executive in charge of medicine at the crossroads. A list of scholarly advisors and a program synopses is attached.« less

PREFACE: Ultrathin layers of graphene, h-BN and other honeycomb structures Ultrathin layers of graphene, h-BN and other honeycomb structures

NASA Astrophysics Data System (ADS)

Geber, Thomas; Oshima, Chuhei

2012-08-01

nanometer scale. This special section contains interesting papers on graphene, h-BN and related 'honeycomb' compounds on solid surfaces, which are currently in development. Interfacial interaction strongly modifies the electronic and atomic structures of these overlayer systems and substrate surfaces. In addition, one can recognize a variety of growth phenomena by changing the surface and growth conditions, which are promising as regards fabricating those noble nanosystems. We have great pleasure in acknowledging the enthusiastic response and participation of our invited authors and their diligent preparation of the manuscripts. Ultrathin layers of graphene, h-BN and other honeycomb structures contents Ultrathin layers of graphene, h-BN and other honeycomb structuresThomas Geber and Chuhei Oshima Templating of arrays of Ru nanoclusters by monolayer graphene/Ru Moirés with different periodicitiesEli Sutter, Bin Wang, Peter Albrecht, Jayeeta Lahiri, Marie-Laure Bocquet and Peter Sutter Controllable p-doping of graphene on Ir(111) by chlorination with FeCl3N A Vinogradov, K A Simonov, A V Generalov, A S Vinogradov, D V Vyalikh, C Laubschat, N Mårtensson and A B Preobrajenski Optimizing long-range order, band gap, and group velocities for graphene on close-packed metal surfacesF D Natterer, S Rusponi, M Papagno, C Carbone and H Brune Epitaxial growth of graphene on transition metal surfaces: chemical vapor deposition versus liquid phase depositionSamuel Grandthyll, Stefan Gsell, Michael Weinl, Matthias Schreck, Stefan Hüfner and Frank Müller High-yield boron nitride nanosheets from 'chemical blowing': towards practical applications in polymer compositesXuebin Wang, Amir Pakdel, Chunyi Zhi, Kentaro Watanabe, Takashi Sekiguchi, Dmitri Golberg and Yoshio Bando BCx layers with honeycomb lattices on an NbB2(0001) surfaceChuhei Oshima Epitaxial growth of boron-doped graphene by thermal decomposition of B4CWataru Norimatsu, Koichiro Hirata, Yuta Yamamoto, Shigeo Arai and Michiko

Fluctuation-enhanced electric conductivity in electrolyte solutions

DOE PAGES

Péraud, Jean-Philippe; Nonaka, Andrew J.; Bell, John B.; ...

2017-09-26

In this work, we analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson–Nernst–Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation–anion diffusion coefficient. Specifically, we predict a nonzero cation–anion Maxwell– Stefan coefficient proportionalmore » to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye–Huckel–Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Lastly, we show that strong applied electric fields result in anisotropically enhanced “giant” velocity fluctuations and reduced fluctuations of salt concentration.« less

Exploring Near-Field Radiative Heat Transfer for Thermo-photovoltaic Applications

NASA Astrophysics Data System (ADS)

Ganjeh, Yashar; Song, Bai; Sadat, Seid; Thompson, Dakotah; Fiorino, Anthony; Reddy, Pramod; Meyhofer, Edgar

2014-03-01

Understanding near-field radiative heat transfer (NFRHT) is critical for developing efficient thermo-photovoltaic devices. Theoretical predictions suggest that when the spatial separation of two parallel planes at different temperatures is less than their Wien's thermal wavelength, thermal transport via radiation can be greatly enhanced. The radiative heat flow across nanoscale gaps is predicted to be orders-of-magnitude higher than that given by Stefan-Boltzmann law, due to contribution of evanescent waves. In order to test these predictions, a novel experimental platform was designed and built enabling parallelization of two planar surfaces (50 μm by 50 μm) with 500 microradian resolution in their relative orientation. This platform was used to probe NFRHT between two planes and also between a plane and a sphere. It was found that, when a 50 μm diameter silica sphere was approximately 20 nm away from a 50 by 50 μm2 silica plane, a significant increase in radiative heat transfer coefficient was observed. This increase is 3 orders of magnitude higher than the value predicted by the blackbody limit. Other setups, including Au spheres and planes, and the plane-plane geometries are currently being investigated. 1) Army Research office (W911NF-12-1-0612), 2) NSF Thermal Transport Prcesses (CBET 1235691), 3) Center for Solar and Thermal Energy conversion, funded by the US Department of Energy, Office of Science, Basic Energy Sciences under award no. DE-SC0000957.

Detailed Multi-dimensional Modeling of Direct Internal Reforming Solid Oxide Fuel Cells.

PubMed

Tseronis, K; Fragkopoulos, I S; Bonis, I; Theodoropoulos, C

2016-06-01

Fuel flexibility is a significant advantage of solid oxide fuel cells (SOFCs) and can be attributed to their high operating temperature. Here we consider a direct internal reforming solid oxide fuel cell setup in which a separate fuel reformer is not required. We construct a multidimensional, detailed model of a planar solid oxide fuel cell, where mass transport in the fuel channel is modeled using the Stefan-Maxwell model, whereas the mass transport within the porous electrodes is simulated using the Dusty-Gas model. The resulting highly nonlinear model is built into COMSOL Multiphysics, a commercial computational fluid dynamics software, and is validated against experimental data from the literature. A number of parametric studies is performed to obtain insights on the direct internal reforming solid oxide fuel cell system behavior and efficiency, to aid the design procedure. It is shown that internal reforming results in temperature drop close to the inlet and that the direct internal reforming solid oxide fuel cell performance can be enhanced by increasing the operating temperature. It is also observed that decreases in the inlet temperature result in smoother temperature profiles and in the formation of reduced thermal gradients. Furthermore, the direct internal reforming solid oxide fuel cell performance was found to be affected by the thickness of the electrochemically-active anode catalyst layer, although not always substantially, due to the counter-balancing behavior of the activation and ohmic overpotentials.

A benchmark study of scoring methods for non-coding mutations.

PubMed

Drubay, Damien; Gautheret, Daniel; Michiels, Stefan

2018-05-15

Detailed knowledge of coding sequences has led to different candidate models for pathogenic variant prioritization. Several deleteriousness scores have been proposed for the non-coding part of the genome, but no large-scale comparison has been realized to date to assess their performance. We compared the leading scoring tools (CADD, FATHMM-MKL, Funseq2 and GWAVA) and some recent competitors (DANN, SNP and SOM scores) for their ability to discriminate assumed pathogenic variants from assumed benign variants (using the ClinVar, COSMIC and 1000 genomes project databases). Using the ClinVar benchmark, CADD was the best tool for detecting the pathogenic variants that are mainly located in protein coding gene regions. Using the COSMIC benchmark, FATHMM-MKL, GWAVA and SOMliver outperformed the other tools for pathogenic variants that are typically located in lincRNAs, pseudogenes and other parts of the non-coding genome. However, all tools had low precision, which could potentially be improved by future non-coding genome feature discoveries. These results may have been influenced by the presence of potential benign variants in the COSMIC database. The development of a gold standard as consistent as ClinVar for these regions will be necessary to confirm our tool ranking. The Snakemake, C++ and R codes are freely available from https://github.com/Oncostat/BenchmarkNCVTools and supported on Linux. damien.drubay@gustaveroussy.fr or stefan.michiels@gustaveroussy.fr. Supplementary data are available at Bioinformatics online.

Portable Infrared Reflectometer Designed and Manufactured for Evaluating Emittance in the Laboratory or in the Field

NASA Technical Reports Server (NTRS)

Jaworske, Donald A.

2000-01-01

The optical properties of materials play a key role in spacecraft thermal control. In space, radiant heat transfer is the only mode of heat transfer that can reject heat from a spacecraft. One of the key properties for defining radiant heat transfer is emittance, a measure of how efficiently a surface can reject heat in comparison to a perfect black body emitter. Heat rejection occurs in the infrared region of the spectrum, nominally in the range of 2 to 25 mm. To calculate emittance, one obtains the reflectance over this spectral range, calculates spectral absorptance by difference, and then uses Kirchhoff s Law and the Stefan-Boltzmann equation to calculate emittance. A new portable infrared reflectometer, the SOC 400t, was designed and manufactured to evaluate the emittance of surfaces and coatings in the laboratory or in the field. It was developed by Surface Optics Corporation under a contract with the NASA Glenn Research Center at Lewis Field to replace the Center s aging Gier-Dunkle DB-100 infrared reflectometer. The specifications for the new instrument include a wavelength range of 2 to 25 mm; reflectance repeatability of +/-1 percent; self-calibrating, near-normal spectral reflectance measurements; a full scan measurement time of 3.5 min, a sample size of 1.27 cm (0.5 in.); a spectral resolution selectable from 4, 8, 16, or 32/cm; and optical property characterization utilizing an automatic integration to calculate total emittance in a selectable temperature range.

Droplet Combustion in a Slow Convective Flow

NASA Technical Reports Server (NTRS)

Nayagam, V.; Hicks, M. C.; Ackerman, M.; Haggard, J. B., Jr.; Williams, F. A.

2003-01-01

The influences of slow convective flow on droplet combustion, particularly in the low Reynolds number regime, have received very little attention in the past. Most studies in the literature are semi-empirical in nature and they were motivated by spray combustion applications in the moderate to high Reynolds number regime. None of the limited number of fundamental theoretical studies applicable to low Reynolds numbers have been verified by rigorous experimental data. Moreover, many unsteady phenomena associated with fluid-dynamic unsteadiness, such as impulsive starting or stopping of a burning droplet, or flow acceleration/deceleration effects, have not been investigated despite their importance in practical applications. In this study we investigate the effects of slow convection on droplet burning dynamics both experimentally and theoretically. The experimental portion of the study involves both ground-based experiments in the drop towers and future flight experiments on board the International Space Station. Heptane and methanol are used as test fuels, and this choice complements the quiescent-environment studies of the Droplet Combustion Experiment (DCE). An analytical model that employs the method of matched asymptotic expansions and uses the ratio of the convective velocity far from the droplet to the Stefan velocity at its surface as the small parameter for expansion has also been developed as a part of this investigation. Results from the ground-based experiments and comparison with the analytical model are presented in this report.

Fluctuation-enhanced electric conductivity in electrolyte solutions

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

Péraud, Jean-Philippe; Nonaka, Andrew J.; Bell, John B.

In this work, we analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson–Nernst–Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation–anion diffusion coefficient. Specifically, we predict a nonzero cation–anion Maxwell– Stefan coefficient proportionalmore » to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye–Huckel–Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Lastly, we show that strong applied electric fields result in anisotropically enhanced “giant” velocity fluctuations and reduced fluctuations of salt concentration.« less

A Multi-Institution Study on the Effectiveness of ClassAction to Promote Student Understanding in Astro 101

NASA Astrophysics Data System (ADS)

Lee, Kevin M.; French, R. S.; Hands, D. R.; Loranz, D. R.; Martino, D.; Rudolph, A. L.; Wysong, J.; Young, T. S.; Prather, E. E.; CATS

2010-01-01

ClassAction is a computer database of materials designed to enhance the conceptual understanding and reasoning abilities of Astro 101 students by promoting interactive engagement and providing rapid feedback. The main focus is dynamic conceptual questions largely based upon graphics that can be projected in the classroom. Instructors have the capability to select, order, and recast these questions into alternate permutations based on their own preferences and student responses. Instructors may also provide feedback through extensive resources including outlines, graphics, and simulations. The Light and Spectroscopy Concept Inventory (LSCI) is a multiple-choice assessment instrument which focuses on the electromagnetic spectrum, Doppler shift, Wien's Law, Stefan-Boltzmann Law, and Kirchhoff's Laws. Illustrative examples of how these concepts are targeted by the questions and resources of the ClassAction module are shown. ClassAction materials covering light and spectra concepts were utilized in multiple classrooms at 6 different institutions and the LSCI was delivered as a pretest and posttest to measure the gains in student understanding. A comparison of the gains achieved in these classes will be made against the national LSCI data. We will report on our investigation into correlations between gain and the extent of ClassAction usage. ClassAction materials are publicly available at http://astro.unl.edu. We would like to thank the NSF for funding under Grant Nos. 0404988 and 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS) Program.

TL detectors for gamma ray dose measurements in criticality accidents.

PubMed

Miljanić, Saveta; Zorko, Benjamin; Gregori, Beatriz; Knezević, Zeljka

2007-01-01

Determination of gamma ray dose in mixed neutron+gamma ray fields is still a demanding task. Dosemeters used for gamma ray dosimetry are usually in some extent sensitive to neutrons and their response variations depend on neutron energy i.e., on neutron spectra. Besides, it is necessary to take into account the energy dependence of dosemeter responses to gamma rays. In this work, several types of thermoluminescent detectors (TLD) placed in different holders used for gamma ray dose determination in the mixed fields were examined. Dosemeters were from three different institutions: Ruder Bosković Institute (RBI), Croatia, JoZef Stefan Institute (JSI), Slovenia and Autoridad Regulatoria Nuclear (ARN), Argentina. All dosemeters were irradiated during the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002. Three accidental scenarios were reproduced and in each irradiation the dosemeters were exposed placed on the front of phantom and 'free in air'. Following types of TLDs were used: 7LiF (TLD-700), CaF2:Mn and Al2O3:Mg,Y-all from RBI; CaF2:Mn from JSI and 7LiF (TLD-700) from ARN. Reported doses were compared with the reference values as well as with the values obtained from the results of all participants. The results show satisfactory agreement with other dosimetry systems used in the Intercomparison. The influence of different types of holders and applied corrections of dosemeters' readings are discussed.

Laying the Foundations of Contemporary Romanian Astronomy

NASA Astrophysics Data System (ADS)

Marin, Sorin

2017-11-01

This article describes the first stage in the history of Romanian astronomy represented by the events, processes and evolution which led to the formation of great scientific personalities, development drives and the creation of the material base for the contemporary Romanian astronomy, having a focus point on the activity of Bucharest Observatory. The article discusses the roots of an evolution pathway determined and inspired by the activity of several scientific personalities of Romania such as Stefan Hepites, Spiru Haret, Nicolae Coculescu and others. It also underlines that a great importance for the astronomical research in Romania was given by the outstanding technical value of the main instruments used at the Observatory in the first decades of activity and, consequentially, by their longevity in service: in the Equatorial Dome - the impressive 6 m. Prin-Mertz telescope and in the Meridian Hall - the GautierPrin telescope. This determined the formation of a powerful astrometry division and a research drive which led over time to important scientific works such as the ultraprecise stellar catalogues developed in Romania at Bucharest Observatory, which were appreciated and awarded nationally and internationally. Therefore, the article includes the moments and the people which determined the success of laying the foundations of the Observatory in 1908 and then having completed the initial scientific infrastructure in 1912 when the construction work was finished, and briefly presents the features, scientific utilisation and outputs of its telescopes, some of the best in the world in their golden years.

Fluctuation-enhanced electric conductivity in electrolyte solutions.

PubMed

Péraud, Jean-Philippe; Nonaka, Andrew J; Bell, John B; Donev, Aleksandar; Garcia, Alejandro L

2017-10-10

We analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson-Nernst-Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation-anion diffusion coefficient. Specifically, we predict a nonzero cation-anion Maxwell-Stefan coefficient proportional to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye-Huckel-Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Finally, we show that strong applied electric fields result in anisotropically enhanced "giant" velocity fluctuations and reduced fluctuations of salt concentration.

Fluctuation-enhanced electric conductivity in electrolyte solutions

PubMed Central

Péraud, Jean-Philippe; Nonaka, Andrew J.; Bell, John B.; Donev, Aleksandar; Garcia, Alejandro L.

2017-01-01

We analyze the effects of an externally applied electric field on thermal fluctuations for a binary electrolyte fluid. We show that the fluctuating Poisson–Nernst–Planck (PNP) equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation result in enhanced charge transport via a mechanism distinct from the well-known enhancement of mass transport that accompanies giant fluctuations. Although the mass and charge transport occurs by advection by thermal velocity fluctuations, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity and a nonzero cation–anion diffusion coefficient. Specifically, we predict a nonzero cation–anion Maxwell–Stefan coefficient proportional to the square root of the salt concentration, a prediction that agrees quantitatively with experimental measurements. The renormalized or effective macroscopic equations are different from the starting PNP equations, which contain no cross-diffusion terms, even for rather dilute binary electrolytes. At the same time, for infinitely dilute solutions the renormalized electric conductivity and renormalized diffusion coefficients are consistent and the classical PNP equations with renormalized coefficients are recovered, demonstrating the self-consistency of the fluctuating hydrodynamics equations. Our calculations show that the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye–Huckel–Onsager theory, while elucidating the physical origins of these corrections and generalizing straightforwardly to more complex multispecies electrolytes. Finally, we show that strong applied electric fields result in anisotropically enhanced “giant” velocity fluctuations and reduced fluctuations of salt concentration. PMID:28973890

Assessment of radiative feedback in climate models using satellite observations of annual flux variation.

PubMed

Tsushima, Yoko; Manabe, Syukuro

2013-05-07

In the climate system, two types of radiative feedback are in operation. The feedback of the first kind involves the radiative damping of the vertically uniform temperature perturbation of the troposphere and Earth's surface that approximately follows the Stefan-Boltzmann law of blackbody radiation. The second kind involves the change in the vertical lapse rate of temperature, water vapor, and clouds in the troposphere and albedo of the Earth's surface. Using satellite observations of the annual variation of the outgoing flux of longwave radiation and that of reflected solar radiation at the top of the atmosphere, this study estimates the so-called "gain factor," which characterizes the strength of radiative feedback of the second kind that operates on the annually varying, global-scale perturbation of temperature at the Earth's surface. The gain factor is computed not only for all sky but also for clear sky. The gain factor of so-called "cloud radiative forcing" is then computed as the difference between the two. The gain factors thus obtained are compared with those obtained from 35 models that were used for the fourth and fifth Intergovernmental Panel on Climate Change assessment. Here, we show that the gain factors obtained from satellite observations of cloud radiative forcing are effective for identifying systematic biases of the feedback processes that control the sensitivity of simulated climate, providing useful information for validating and improving a climate model.

The turning point for Einstein's Annus mirabilis

NASA Astrophysics Data System (ADS)

Rynasiewicz, Robert; Renn, Jürgen

The year 1905 has been called Einstein's Annus mirabilis because of three ground-breaking works completed over the span of a few months-the light-quantum paper, the Brownian motion paper, and the paper on the electrodynamics of moving bodies introducing the special theory of relativity. There are prima facie reasons for thinking that the origins of these papers cannot be understood in isolation from one another. Due to space limitations, we concentrate primarily on the light quantum paper, since, in key respects, it marks the turning point for the Annus mirabilis. The task is to probe, not just how the idea of the light quantum might have occurred to Einstein, but, more importantly, what convinced him that the idea was not just a quixotic hypothesis, but an unavoidable and demonstrable feature of radiation. The crucial development, we suggest, arose from comparing the energy fluctuations that follow rigorously from the Stefan-Boltzmann law, as well as from Wien's distribution formula for blackbody radiation, with what it is reasonable to expect from Maxwell's electromagnetic theory of light. A special case of this is addressed in Einstein's one paper from 1904, "Zur allgemeinen molekularen Theorie der Wärme". Annalen der Physik, 14, 355-362 (Also in CPAE, Vol. 2, Doc. 5)]. The outcome for the general case leads naturally to the central theoretical argument of the light quantum paper, the expectation of Brownian-like motion, and several of the key results for the electrodynamics of moving bodies.

Thermal radiative and thermodynamic properties of solid and liquid uranium and plutonium carbides in the visible-near-infrared range

NASA Astrophysics Data System (ADS)

Fisenko, Anatoliy I.; Lemberg, Vladimir F.

2016-09-01

The knowledge of thermal radiative and thermodynamic properties of uranium and plutonium carbides under extreme conditions is essential for designing a new metallic fuel materials for next generation of a nuclear reactor. The present work is devoted to the study of the thermal radiative and thermodynamic properties of liquid and solid uranium and plutonium carbides at their melting/freezing temperatures. The Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, pressure, and normal total emissivity are calculated using experimental data for the frequency dependence of the normal spectral emissivity of liquid and solid uranium and plutonium carbides in the visible-near infrared range. It is shown that the thermal radiative and thermodynamic functions of uranium carbide have a slight difference during liquid-to-solid transition. Unlike UC, such a difference between these functions have not been established for plutonium carbide. The calculated values for the normal total emissivity of uranium and plutonium carbides at their melting temperatures is in good agreement with experimental data. The obtained results allow to calculate the thermal radiative and thermodynamic properties of liquid and solid uranium and plutonium carbides for any size of samples. Based on the model of Hagen-Rubens and the Wiedemann-Franz law, a new method to determine the thermal conductivity of metals and carbides at the melting points is proposed.

Process of optimization of district heat production by utilizing waste energy from metallurgical processes

NASA Astrophysics Data System (ADS)

Konovšek, Damjan; Fužir, Miran; Slatinek, Matic; Šepul, Tanja; Plesnik, Kristijan; Lečnik, Samo

2017-07-01

In a consortium with SIJ (Slovenian Steel Group), Metal Ravne, the local community of Ravne na Koro\\vskem and the public research Institut Jožef Stefan, with its registered office in Slovenia, Petrol Energetika, d.o.o. set up a technical and technological platform of an innovative energy case for a transition of steel industry into circular economy with a complete energy solution called »Utilization of Waste Heat from Metallurgical Processes for District Heating of Ravne na Koro\\vskem. This is the first such project designed for a useful utilization of waste heat in steel industry which uses modern technology and innovative system solutions for an integration of a smart, efficient and sustainable heating and cooling system and which shows a growth potential. This will allow the industry and cities to make energy savings, to improve the quality of air and to increase the benefits for the society we live in. On the basis of circular economy, we designed a target-oriented co-operation of economy, local community and public research institute to produce new business models where end consumers are put into the centre. This innovation opens the door for steel industry and local community to a joint aim that is a transition into efficient low-carbon energy systems which are based on involvement of natural local conditions, renewable energy sources, the use of waste heat and with respect for the principles of sustainable development.

High Energy Theory Workshops and Visitors at the Michigan Center for Theoretical Physics FY15

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

Pierce, Aaron T.

The String theory workshop was held from March 4-7, 2015 on the University of Michigan campus. Local organizers were Gordon Kane and Aaron Pierce. Piyush Kumar (Yale), Jim Halverson (KITP), Bobby Acharya (ICTP) and Sven Krippendorf (Oxford) served as external organizers.The meeting focused on the status of work to project 10 or 11 dimensional string/M theories onto our 4 spacetime dimensions (compactification). The workshop had 31 participants, half from outside the U.S. Participants were encouraged to focus on predictions for recent and forthcoming data, particularly for Higgs physics and LHC and dark matter, rather than on the traditional approach ofmore » embedding the Standard Model particles and forces. The Higgs boson sympoosium was locally organized by James Wells (chair), Aaron Pierce and Jianming Qian. Additional input in the early stages by Stefan Pokorski (Warsaw) who was unable to attend in the end. The workshop consistent of 22 talks from experts around the world, both theoretical and experimental. Experimentalists summarized the current state of knowledge of the Higgs boson and its varients. The theory talks ranged from technical calculations of Standard Model processes to speculative novel ideas. The YHET visitor program invited weekly young visitors to the University of Michigan campus to present their work. This year 24 participants came under the program, with 17 of them receiving at least partial support for their visits.« less

Trapping Dust to Form Planets

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-10-01

Growing a planet from a dust grain is hard work! A new study explores how vortices in protoplanetary disks can assist this process.When Dust Growth FailsTop: ALMA image of the protoplanetary disk of V1247 Orionis, with different emission components labeled. Bottom: Synthetic image constructed from the best-fit model. [Kraus et al. 2017]Gradual accretion onto a seed particle seems like a reasonable way to grow a planet from a grain of dust; after all, planetary embryos orbit within dusty protoplanetary disks, which provides them with plenty of fuel to accrete so they can grow. Theres a challenge to this picture, though: the radial drift problem.The radial drift problem acknowledges that, as growing dust grains orbit within the disk, the drag force on them continues to grow as well. For large enough dust grains perhaps around 1 millimeter the drag force will cause the grains orbits to decay, and the particles drift into the star before they are able to grow into planetesimals and planets.A Close-Up Look with ALMASo how do we overcome the radial drift problem in order to form planets? A commonly proposed mechanism is dust trapping, in which long-lived vortices in the disk trap the dust particles, preventing them from falling inwards. This allows the particles to persist for millions of years long enough to grow beyond the radial drift barrier.Observationally, these dust-trapping vortices should have signatures: we would expect to see, at millimeter wavelengths, specific bright, asymmetric structures where the trapping occurs in protoplanetary disks. Such disk structures have been difficult to spot with past instrumentation, but the Atacama Large Millimeter/submillimeter Array (ALMA) has made some new observations of the disk V1247 Orionis that might be just what were looking for.Schematic of the authors model for the disk of V1247 Orionis. [Kraus et al. 2017]Trapped in a Vortex?ALMAs observations of V1247 Orionis are reported by a team of scientists led by Stefan

An open-source library for the numerical modeling of mass-transfer in solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Novaresio, Valerio; García-Camprubí, María; Izquierdo, Salvador; Asinari, Pietro; Fueyo, Norberto

2012-01-01

The generation of direct current electricity using solid oxide fuel cells (SOFCs) involves several interplaying transport phenomena. Their simulation is crucial for the design and optimization of reliable and competitive equipment, and for the eventual market deployment of this technology. An open-source library for the computational modeling of mass-transport phenomena in SOFCs is presented in this article. It includes several multicomponent mass-transport models ( i.e. Fickian, Stefan-Maxwell and Dusty Gas Model), which can be applied both within porous media and in porosity-free domains, and several diffusivity models for gases. The library has been developed for its use with OpenFOAM ®, a widespread open-source code for fluid and continuum mechanics. The library can be used to model any fluid flow configuration involving multicomponent transport phenomena and it is validated in this paper against the analytical solution of one-dimensional test cases. In addition, it is applied for the simulation of a real SOFC and further validated using experimental data. Program summaryProgram title: multiSpeciesTransportModels Catalogue identifier: AEKB_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKB_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 18 140 No. of bytes in distributed program, including test data, etc.: 64 285 Distribution format: tar.gz Programming language:: C++ Computer: Any x86 (the instructions reported in the paper consider only the 64 bit case for the sake of simplicity) Operating system: Generic Linux (the instructions reported in the paper consider only the open-source Ubuntu distribution for the sake of simplicity) Classification: 12 External routines: OpenFOAM® (version 1.6-ext) ( http://www.extend-project.de) Nature of problem: This software provides a library of models for

Brugga basin's TACD Model Adaptation to current GIS PCRaster 4.1

NASA Astrophysics Data System (ADS)

Lopez Rozo, Nicolas Antonio; Corzo Perez, Gerald Augusto; Santos Granados, Germán Ricardo

2017-04-01

The process-oriented catchment model TACD (Tracer-Aided Catchment model - Distributed) was developed in the Brugga Basin (Dark Forest, Germany) with a modular structure in the Geographic Information System PCRaster Version 2, in order to dynamically model the natural processes of a complex Basin, such as rainfall, air temperature, solar radiation, evapotranspiration and flow routing among others. Further research and application on this model has been done, such as adapting other meso-scaled basins and adding erosion processes in the hydrological model. However, TACD model is computationally intensive. This has made it not efficient on large and well discretized river basins. Aswell, the current version is not compatible with latest PCRaster Version 4.1, which offers new capabilities on 64-bit hardware architecture, hydraulic calculation improvements, in maps creation, some error and bug fixes. The current work studied and adapted TACD model into the latest GIS PCRaster Version 4.1. This was done by editing the original scripts, replacing deprecated functionalities without losing correctness of the TACD model. The correctness of the adapted TACD model was verified by using the original study case of the Brugga Basin and comparing the adapted model results with the original model results by Stefan Roser in 2001. Small differences were found due to the fact that some hydraulic and hydrological routines were optimized since version 2 of GIS PCRaster. Therefore, the hydraulic and hydrological processes are well represented. With this new working model, further research and development on current topics like uncertainty analysis, GCM downscaling techniques and spatio-temporal modelling are encouraged.

Modeling Studies of PVT Growth of ZnSe: Current Status and Future Course

NASA Technical Reports Server (NTRS)

Ramachandran, N.; Su, Ching-Hua

1999-01-01

Bulk growth of wide band gap II-VI semiconductors by physical vapor transport (PVT) has been developed and refined over the past several years at NASA Marshall Space Flight Center. Results from a modeling study of PVT crystal growth of ZnSe are reported in this paper. The PVT process is numerically investigated using a two-dimensional formulation of the governing equations and associated boundary conditions. Both the incompressible Boussinesq approximation and a compressible model are tested to determine the influence of gravity on the process and to discern the differences between the two approaches. The influence of a residual gas is included in the models. The results show that both the incompressible and compressible approximations provide comparable results and the presence of a residual gas tends to measurably reduce the mass flux in the system. Detailed flow, thermal and concentration profiles are provided. The simulations show that the Stefan flux dominates the system flow field and the subtle gravitational effects can be gauged by subtracting this flux from the calculated profiles. Shear flows, due to solutal buoyancy, of the order of 50 microns/s for the liorizont,-d growth orientation and 10 microns/s for the vertical orientation are predicted. Whether these flows can fully account for the observed gravity related growth morphological effects and inhomogeneous solute and dopant distributions is a matter of conjecture. A template for future modeling efforts in this area is suggested which incorporates a mathematical approach to the tracking of the growth front based on energy of formation concepts.

chipPCR: an R package to pre-process raw data of amplification curves.

PubMed

Rödiger, Stefan; Burdukiewicz, Michał; Schierack, Peter

2015-09-01

Both the quantitative real-time polymerase chain reaction (qPCR) and quantitative isothermal amplification (qIA) are standard methods for nucleic acid quantification. Numerous real-time read-out technologies have been developed. Despite the continuous interest in amplification-based techniques, there are only few tools for pre-processing of amplification data. However, a transparent tool for precise control of raw data is indispensable in several scenarios, for example, during the development of new instruments. chipPCR is an R: package for the pre-processing and quality analysis of raw data of amplification curves. The package takes advantage of R: 's S4 object model and offers an extensible environment. chipPCR contains tools for raw data exploration: normalization, baselining, imputation of missing values, a powerful wrapper for amplification curve smoothing and a function to detect the start and end of an amplification curve. The capabilities of the software are enhanced by the implementation of algorithms unavailable in R: , such as a 5-point stencil for derivative interpolation. Simulation tools, statistical tests, plots for data quality management, amplification efficiency/quantification cycle calculation, and datasets from qPCR and qIA experiments are part of the package. Core functionalities are integrated in GUIs (web-based and standalone shiny applications), thus streamlining analysis and report generation. http://cran.r-project.org/web/packages/chipPCR. Source code: https://github.com/michbur/chipPCR. stefan.roediger@b-tu.de Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

An interdiffusional model for prediction of the interaction layer growth in the system uranium molybdenum/aluminum

NASA Astrophysics Data System (ADS)

Soba, A.; Denis, A.

2007-03-01

The codes PLACA and DPLACA, elaborated in this working group, simulate the behavior of a plate-type fuel containing in its core a foil of monolithic or dispersed fissile material, respectively, under normal operation conditions of a research reactor. Dispersion fuels usually consist of ceramic particles of a uranium compound in a high thermal conductivity matrix. The use of particles of a U-Mo alloy in a matrix of Al requires especially devoted subroutines able to simulate the growth of the interaction layer that develops between the particles and the matrix. A model is presented in this work that gives account of these particular phenomena. It is based on the assumption that diffusion of U and Al through the layer is the rate-determining step. Two moving interfaces separate the growing reaction layer from the original phases. The kinetics of these boundaries are solved as Stefan problems. In order to test the model and the associated code, some previous, simpler problems corresponding to similar systems for which analytical solutions or experimental data are known were simulated. Experiments performed with planar U-Mo/Al diffusion couples are reported in the literature, which purpose is to obtain information on the system parameters. These experiments were simulated with PLACA. Results of experiments performed with U-Mo particles disperse in Al either without or with irradiation, published in the open literature were simulated with DPLACA. A satisfactory prediction of the whole reaction layer thickness and of the individual fractions corresponding to alloy and matrix consumption was obtained.

Diffusion of interacting particles in discrete geometries: Equilibrium and dynamical properties

NASA Astrophysics Data System (ADS)

Becker, T.; Nelissen, K.; Cleuren, B.; Partoens, B.; Van den Broeck, C.

2014-11-01

We expand on a recent study of a lattice model of interacting particles [Phys. Rev. Lett. 111, 110601 (2013), 10.1103/PhysRevLett.111.110601]. The adsorption isotherm and equilibrium fluctuations in particle number are discussed as a function of the interaction. Their behavior is similar to that of interacting particles in porous materials. Different expressions for the particle jump rates are derived from transition-state theory. Which expression should be used depends on the strength of the interparticle interactions. Analytical expressions for the self- and transport diffusion are derived when correlations, caused by memory effects in the environment, are neglected. The diffusive behavior is studied numerically with kinetic Monte Carlo (kMC) simulations, which reproduces the diffusion including correlations. The effect of correlations is studied by comparing the analytical expressions with the kMC simulations. It is found that the Maxwell-Stefan diffusion can exceed the self-diffusion. To our knowledge, this is the first time this is observed. The diffusive behavior in one-dimensional and higher-dimensional systems is qualitatively the same, with the effect of correlations decreasing for increasing dimension. The length dependence of both the self- and transport diffusion is studied for one-dimensional systems. For long lengths the self-diffusion shows a 1 /L dependence. Finally, we discuss when agreement with experiments and simulations can be expected. The assumption that particles in different cavities do not interact is expected to hold quantitatively at low and medium particle concentrations if the particles are not strongly interacting.

Section Editors

NASA Astrophysics Data System (ADS)

Groep, D. L.; Bonacorsi, D.

2014-06-01

1. Data Acquisition, Trigger and Controls Niko NeufeldCERNniko.neufeld@cern.ch Tassos BeliasDemokritosbelias@inp.demokritos.gr Andrew NormanFNALanorman@fnal.gov Vivian O'DellFNALodell@fnal.gov 2. Event Processing, Simulation and Analysis Rolf SeusterTRIUMFseuster@cern.ch Florian UhligGSIf.uhlig@gsi.de Lorenzo MonetaCERNLorenzo.Moneta@cern.ch Pete ElmerPrincetonpeter.elmer@cern.ch 3. Distributed Processing and Data Handling Nurcan OzturkU Texas Arlingtonnurcan@uta.edu Stefan RoiserCERNstefan.roiser@cern.ch Robert IllingworthFNAL Davide SalomoniINFN CNAFDavide.Salomoni@cnaf.infn.it Jeff TemplonNikheftemplon@nikhef.nl 4. Data Stores, Data Bases, and Storage Systems David LangeLLNLlange6@llnl.gov Wahid BhimjiU Edinburghwbhimji@staffmail.ed.ac.uk Dario BarberisGenovaDario.Barberis@cern.ch Patrick FuhrmannDESYpatrick.fuhrmann@desy.de Igor MandrichenkoFNALivm@fnal.gov Mark van de SandenSURF SARA sanden@sara.nl 5. Software Engineering, Parallelism & Multi-Core Solveig AlbrandLPSC/IN2P3solveig.albrand@lpsc.in2p3.fr Francesco GiacominiINFN CNAFfrancesco.giacomini@cnaf.infn.it Liz SextonFNALsexton@fnal.gov Benedikt HegnerCERNbenedikt.hegner@cern.ch Simon PattonLBNLSJPatton@lbl.gov Jim KowalkowskiFNAL jbk@fnal.gov 6. Facilities, Infrastructures, Networking and Collaborative Tools Maria GironeCERNMaria.Girone@cern.ch Ian CollierSTFC RALian.collier@stfc.ac.uk Burt HolzmanFNALburt@fnal.gov Brian Bockelman U Nebraskabbockelm@cse.unl.edu Alessandro de SalvoRoma 1Alessandro.DeSalvo@ROMA1.INFN.IT Helge MeinhardCERN Helge.Meinhard@cern.ch Ray PasetesFNAL rayp@fnal.gov Steven GoldfarbU Michigan Steven.Goldfarb@cern.ch

Use of Computed X-ray Tomographic Data for Analyzing the Thermodynamics of a Dissociating Porous Sand/Hydrate Mixture

DOE R&D Accomplishments Database

Freifeld, Barry M.; Kneafsey, Timothy J.; Tomutsa, Liviu; Stern, Laura A.; Kirby, Stephen H.

2002-02-28

X-ray computed tomography (CT) is a method that has been used extensively in laboratory experiments for measuring rock properties and fluid transport behavior. More recently, CT scanning has been applied successfully to detect the presence and study the behavior of naturally occurring hydrates. In this study, we used a modified medical CT scanner to image and analyze the progression of a dissociation front in a synthetic methane hydrate/sand mixture. The sample was initially scanned under conditions at which the hydrate is stable (atmospheric pressure and liquid nitrogen temperature, 77 K). The end of the sample holder was then exposed to the ambient air, and the core was continuously scanned as dissociation occurred in response to the rising temperature. CT imaging captured the advancing dissociation front clearly and accurately. The evolved gas volume was monitored as a function of time. Measured by CT, the advancing hydrate dissociation front was modeled as a thermal conduction problem explicitly incorporating the enthalpy of dissociation, using the Stefan moving-boundary-value approach. The assumptions needed to perform the analysis consisted of temperatures at the model boundaries. The estimated value for thermal conductivity of 2.6 W/m K for the remaining water ice/sand mixture is higher than expected based on conduction alone; this high value may represent a lumped parameter that incorporates the processes of heat conduction, methane gas convection, and any kinetic effects that occur during dissociation. The technique presented here has broad implications for future laboratory and field testing that incorporates geophysical techniques to monitor gas hydrate dissociation.

Investigating the validity of the Knudsen prescription for diffusivities in a mesoporous covalent organic framework

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

Krishna, Rajamani; van Baten, Jasper M.

2011-04-27

Molecular dynamics (MD) simulations were performed to determine the self-diffusivity (D i,self) and the Maxwell–Stefan diffusivity (Ð I) of hydrogen, argon, carbon dioxide, methane, ethane, propane, n-butane, n-pentane, and n-hexane in BTP-COF, which is a covalent organic framework (COF) that has one-dimensional 3.4-nm-sized channels. The MD simulations show that the zero-loading diffusivity (Ð I(0)) is consistently lower, by up to a factor of 10, than the Knudsen diffusivity (D i,Kn) values. The ratio Ð I(0)/D i,Kn is found to correlate with the isosteric heat of adsorption, which, in turn, is a reflection of the binding energy for adsorption on themore » pore walls: the stronger the binding energy, the lower the ratio Ð I(0)/D i,Kn. The diffusion selectivity, which is defined by the ratio D 1,self/D 2,self for binary mixtures, was determined to be significantly different from the Knudsen selectivity (M 2/M 1) 1/2, where M I is the molar mass of species i. For mixtures in which component 2 is more strongly adsorbed than component 1, the expression (D 1,self/D 2,self)/(M 2/M 1)1/2 has values in the range of 1–10; the departures from the Knudsen selectivity increased with increasing differences in adsorption strengths of the constituent species. The results of this study have implications in the modeling of diffusion within mesoporous structures, such as MCM-41 and SBA-15.« less

Historical and future changes of frozen ground in the upper Yellow River Basin

NASA Astrophysics Data System (ADS)

Wang, Taihua; Yang, Dawen; Qin, Yue; Wang, Yuhan; Chen, Yun; Gao, Bing; Yang, Hanbo

2018-03-01

Frozen ground degradation resulting from climate warming on the Tibetan Plateau has aroused wide concern in recent years. In this study, the maximum thickness of seasonally frozen ground (MTSFG) is estimated by the Stefan equation, which is validated using long-term frozen depth observations. The permafrost distribution is estimated by the temperature at the top of permafrost (TTOP) model, which is validated using borehole observations. The two models are applied to the upper Yellow River Basin (UYRB) for analyzing the spatio-temporal changes in frozen ground. The simulated results show that the areal mean MTSFG in the UYRB decreased by 3.47 cm/10 a during 1965-2014, and that approximately 23% of the permafrost in the UYRB degraded to seasonally frozen ground during the past 50 years. Using the climate data simulated by 5 General Circulation Models (GCMs) under the Representative Concentration Pathway (RCP) 4.5, the areal mean MTSFG is projected to decrease by 1.69 to 3.07 cm/10 a during 2015-2050, and approximately 40% of the permafrost in 1991-2010 is projected to degrade into seasonally frozen ground in 2031-2050. This study provides a framework to estimate the long-term changes in frozen ground based on a combination of multi-source observations at the basin scale, and this framework can be applied to other areas of the Tibetan Plateau. The estimates of frozen ground changes could provide a scientific basis for water resource management and ecological protection under the projected future climate changes in headwater regions on the Tibetan Plateau.

The structure and spectrum of the accretion shock in the atmospheres of young stars

NASA Astrophysics Data System (ADS)

Dodin, Alexandr

2018-04-01

The structure and spectrum of the accretion shock have been self-consistently simulated for a wide range of parameters typical for Classical T Tauri Stars (CTTS). Radiative cooling of the shocked gas was calculated, taking into account the self-absorption and non-equilibrium (time-dependent) effects in the level populations. These effects modify the standard cooling curve for an optically thin plasma in coronal equilibrium, however the shape of high-temperature (T > 3 × 105 K) part of the curve remains unchanged. The applied methods allow us to smoothly describe the transition from the cooling flow to the hydrostatic stellar atmosphere. Thanks to this approach, it has been found that the narrow component of He II lines is formed predominantly in the irradiated stationary atmosphere (hotspot), i.e. at velocities of the settling gas <2 km s-1. The structure of the pre-shock region is calculated simultaneously with the heated atmosphere. The simulation shows that the pre-shock gas produces a noticeable emission component in He II lines and practically does not manifest itself in He I lines (λλ 5876, 10830 Å). The ultraviolet spectrum of the hotspot is distorted by the pre-shock gas, namely numerous red-shifted emission and absorption lines overlap each other forming a pseudo-continuum. The spectrum of the accretion region at high pre-shock densities ˜1014 cm-3 is fully formed in the in-falling gas and can be qualitatively described as a spectrum of a star with an effective temperature derived from the Stefan-Boltzmann law via the full energy flux.

Ward-based interventions for patients with hemispatial neglect in stroke rehabilitation: a systematic literature review.

PubMed

Klinke, Marianne E; Hafsteinsdóttir, Thóra B; Hjaltason, Haukur; Jónsdóttir, Helga

2015-08-01

To identify rehabilitation interventions that can be integrated into ward-based nursing for patients with hemispatial neglect following stroke in the right brain hemisphere. A systematic review of interdisciplinary literature. A preliminary literature search without time limits was conducted in the Cochrane Controlled Trials Register. We then searched the PubMed, CINAHL and PsychINFO databases for relevant articles published between January 2006 and June 2014. Selected journals were searched manually. Additional resources were explored by scrutinizing reference lists and tracking citations of the selected articles. Titles and abstracts were matched with the inclusion criteria. Articles were read in their entirety if the abstracts adhered to inclusion criteria or if there was any uncertainty. Two reviewers evaluated the risk of methodological bias independently by using quantitative appraisal forms from the Johanna Briggs Institute (JBI). Any disagreements were resolved by consensus. Authors of nine studies were contacted to acquire additional information. The JBI Reviewers' Manual was used to guide the overall procedure of the review. We used the PRISMA statement to ensure precise reporting of the results. The selected studies were graded according to the strength of their evidence (Levels 1-5); the proposed interventions were given recommendation grades (Grades A-D). Using 41 original studies, 11 interventions were identified. These comprise: (1) contralesional neck vibration (Grade C); (2) emotionally salient stimuli and reward (Grade D); (3) family participation and intensity of training (Grade C); (4) limb activation training (Grade C); (5) mental imagery training, (Grade D); (6) mirror therapy (Grade C); (7) music therapy (Grade D); (8) right half-field eye patching (Grade D); (9) smooth pursuit eye-movement training (Grade B); (10) virtual reality and computer-based training (Grade C); and (11) visual scanning training (Grade D). A total of 11 promising

Evaluating the CARE4Carer Blended Care Intervention for Partners of Patients With Acquired Brain Injury: Protocol for a Randomized Controlled Trial.

PubMed

Cox, Vincent Cm; Schepers, Vera Pm; Ketelaar, Marjolijn; van Heugten, Caroline M; Visser-Meily, Johanna Ma

2018-02-16

partners of patients with acquired brain injury. Barriers and facilitators that emerge from the process evaluation will be used in the nationwide implementation of the intervention. Dutch Trial Register NTR6197; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6197 (Archived by WebCite at http://www.webcitation.org/6xHBAxx0y). ©Vincent CM Cox, Vera PM Schepers, Marjolijn Ketelaar, Caroline M van Heugten, Johanna MA Visser-Meily. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 16.02.2018.

Preface: phys. stat. sol. (a) 202/11

NASA Astrophysics Data System (ADS)

Bergonzo, Philippe; Nesládek, Milo

2005-09-01

The present issue of physica status solidi (a) contains a collection of 31 papers presented at the 10th International Workshop on Surface and Bulk Defects in CVD Diamond Films held in Diepenbeek-Hasselt, Belgium, 23-25 February 2005. The 10th anniversary of the meeting proved the success of the concept, which originated in 1996 with the idea of bringing together scientists who are active and innovative in the field of electronic and optical properties of thin film diamond. This year the programme contained 9 invited oral talks, 14 contributed oral talks and 34 posters. 103 Participants from 14 countries (Austria, Belgium, Czech Republic, Finland, France, Germany, Japan, Mexico, Poland, Slovak Republic, Sweden, Switzerland, UK, USA) took part in the meeting. The meeting was traditionally directed towards topics ranging from defects and their characterization as well as electrical transport in CVD diamond towards modern diamond thin film devices including bio-sensing applications. Also, diamond homoepitaxial and heteroepitaxial growth, doping, hydrogen induced surface conductivity and several other topics including defects in boron nitride materials were addressed. Intense and lively discussions were as usual part of this meeting to which the hospitality of the city of Hasselt contributed greatly.The workshop would have not been possible without the support of many people and institutions. We also acknowledge the financial support of the Scientific Research Community of the F.W.O.-Vlaanderen (Belgium) and the University of Hasselt. We also thank the editorial staff of physica status solidi, most notably Stefan Hildebrandt, for their excellent and patient work. Finally, we would like to thank Ken Haenen, whose skills for the successful organization are gratefully acknowledged.August 2005

Low velocity opposed-flow frame spread in a transport-controlled environment DARTFire

NASA Technical Reports Server (NTRS)

West, Jeff; Thomas, Pete; Chao, Ruian; Bhattacharjee, Subrata; Tang, TI; Altenkirch, Robert A.; Olson, Sandra L.

1995-01-01

The overall objectives of the DARTFire project are to uncover the underlying physics and increase understanding of the mechanisms that cause flames to propagate over solid fuels against a low velocity of oxidizer flow in a low-gravity environment. Specific objectives are (1) to analyze experimentally observed flame shapes, measured gas-phase field variables, spread rates, radiative characteristics, and solid-phase regression rates for comparison with previously developed model prediction capability that will be continually extended, and (2) to investigate the transition from ignition to either flame propagation or extinction in order to determine the characteristics of those environments that lead to flame evolution. To meet the objectives, a series of sounding rocket experiments has been designed to exercise several of the dimensional, controllable variables that affect the flame spread process over PMMA in microgravity, i.e., the opposing flow velocity (1-20 cm/s), the external radiant flux directed to the fuel surface (0-2 W/cm(exp 2)), and the oxygen concentration of the environment (35-70%). Because radiative heat transfer is critical to these microgravity flame spread experiments, radiant heating is imposed, and radiant heat loss will be measured. These are the first attempts at such an experimental control and measurement in microgravity. Other firsts associated with the experiment are (1) the control of the low velocity, opposed flow, which is of the same order as diffusive velocities and Stefan flows; (2) state-of-the-art quantitative flame imaging for species-specific emissions (both infrared and ultraviolet) in addition to novel intensified array imaging to obtain a color image of the very dim, low-gravity flames.

Fluid Creep Effects on Near-Wall Solute Transport for Non-Isothermal Ampoules

NASA Technical Reports Server (NTRS)

Papadopoulos, Dimitrios; Rosner, Daniel E.

1996-01-01

There is a growing practical and theoretical interest in developing accurate macroscopic modelling for flows arising in chemical or physical vapor transport (VT) crystal growth experiments, including those conducted in reduced gravity environments. Rosner was the first person to point out that previously neglected rarefield gas dynamics phenomena (Stefan and bouyancy-driven flows) become rather important sources of convection. In particular, the combination of rarefaction and strong gradients of temperature (and/or concentration) tangential to the side-walls of the ampoule induces convective flows known as thermal (and concentration) 'creep' respectively. His order-of-magnitude estimates revealed that thermal creep effects can be non-negligible even at normal gravitational levels. On the macroscopic level, the bulk fluid mechanics can be adequately described by the familiar macroscopic equations as long as the boundary conditions are modified to account for the integrated effect of kinetic boundary layers adjacent to solid boundaries. Motivated by the growing importance of these phenomena, we have embarked on a series of computational studies to elucidate these fundamental creep-induced effects for a rarefied gas in simple, two-dimensional confined geometries. However, unlike previous related studies, we resort to a microscopic description of the gas, mathematically expressed by the Boltzmann integro-differential equation. We employ the direct simulation Monte Carlo (DSMC) method of Bird, the theoretical foundations and several practical applications. In the case of thermally induced flows, the no-time counter method of Bird is used, as implemented for a hard-sphere gas. The scheme has been also extended to account for realistic molecular interaction models, an extension necessary if the diffusion physics underlying concentration creep are to be captured.

System for Thermal Imaging of Hot Moving Objects

NASA Technical Reports Server (NTRS)

Weinstein, Leonard; Hundley, Jason

2007-01-01

The High Altitude/Re-Entry Vehicle Infrared Imaging (HARVII) system is a portable instrumentation system for tracking and thermal imaging of a possibly distant and moving object. The HARVII is designed specifically for measuring the changing temperature distribution on a space shuttle as it reenters the atmosphere. The HARVII system or other systems based on the design of the HARVII system could also be used for such purposes as determining temperature distributions in fires, on volcanoes, and on surfaces of hot models in wind tunnels. In yet another potential application, the HARVII or a similar system would be used to infer atmospheric pollution levels from images of the Sun acquired at multiple wavelengths over regions of interest. The HARVII system includes the Ratio Intensity Thermography System (RITS) and a tracking subsystem that keeps the RITS aimed at the moving object of interest. The subsystem of primary interest here is the RITS (see figure), which acquires and digitizes images of the same scene at different wavelengths in rapid succession. Assuming that the time interval between successive measurements is short enough that temperatures do not change appreciably, the digitized image data at the different wavelengths are processed to extract temperatures according to the principle of ratio-intensity thermography: The temperature at a given location in a scene is inferred from the ratios between or among intensities of infrared radiation from that location at two or more wavelengths. This principle, based on the Stefan-Boltzmann equation for the intensity of electromagnetic radiation as a function of wavelength and temperature, is valid as long as the observed body is a gray or black body and there is minimal atmospheric absorption of radiation.

Dynamical generation of a repulsive vector contribution to the quark pressure

NASA Astrophysics Data System (ADS)

Restrepo, Tulio E.; Macias, Juan Camilo; Pinto, Marcus Benghi; Ferrari, Gabriel N.

2015-03-01

Lattice QCD results for the coefficient c2 appearing in the Taylor expansion of the pressure show that this quantity increases with the temperature towards the Stefan-Boltzmann limit. On the other hand, model approximations predict that when a vector repulsion, parametrized by GV, is present this coefficient reaches a maximum just after Tc and then deviates from the lattice predictions. Recently, this discrepancy has been used as a guide to constrain the (presently unknown) value of GV within the framework of effective models at large Nc (LN). In the present investigation we show that, due to finite Nc effects, c2 may also develop a maximum even when GV=0 since a vector repulsive term can be dynamically generated by exchange-type radiative corrections. Here we apply the optimized perturbation theory (OPT) method to the two-flavor Polyakov-Nambu-Jona-Lasinio model (at GV=0 ) and compare the results with those furnished by lattice simulations and by the LN approximation at GV=0 and also at GV≠0 . The OPT numerical results for c2 are impressively accurate for T ≲1.2 Tc but, as expected, they predict that this quantity develops a maximum at high T . After identifying the mathematical origin of this extremum we argue that such a discrepant behavior may naturally arise within this type of effective quark theories (at GV=0 ) whenever the first 1 /Nc corrections are taken into account. We then interpret this hypothesis as an indication that beyond the large-Nc limit the correct high-temperature (perturbative) behavior of c2 will be faithfully described by effective models only if they also mimic the asymptotic freedom phenomenon.

Heat transfer analytical models for the rapid determination of cooling time in crystalline thermoplastic injection molding and experimental validation

NASA Astrophysics Data System (ADS)

Didier, Delaunay; Baptiste, Pignon; Nicolas, Boyard; Vincent, Sobotka

2018-05-01

Heat transfer during the cooling of a thermoplastic injected part directly affects the solidification of the polymer and consequently the quality of the part in term of mechanical properties, geometric tolerance and surface aspect. This paper proposes to mold designers a methodology based on analytical models to provide quickly the time to reach the ejection temperature depending of the temperature and the position of cooling channels. The obtained cooling time is the first step of the thermal conception of the mold. The presented methodology is dedicated to the determination of solidification time of a semi-crystalline polymer slab. It allows the calculation of the crystallization time of the part and is based on the analytical solution of the Stefan problem in a semi-infinite medium. The crystallization is then considered as a phase change with an effective crystallization temperature, which is obtained from Fast Scanning Calorimetry (FSC) results. The crystallization time is then corrected to take the finite thickness of the part into account. To check the accuracy of such approach, the solidification time is calculated by solving the heat conduction equation coupled to the crystallization kinetics of the polymer. The impact of the nature of the contact between the polymer and the mold is evaluated. The thermal contact resistance (TCR) appears as significant parameter that needs to be taken into account in the cooling time calculation. The results of the simplified model including or not TCR are compared in the case of a polypropylene (PP) with experiments carried out with an instrumented mold. Then, the methodology is applied for a part made with PolyEtherEtherKetone (PEEK).

Determination of the thermodynamic correction factor of fluids confined in nano-metric slit pores from molecular simulation

NASA Astrophysics Data System (ADS)

Collell, Julien; Galliero, Guillaume

2014-05-01

The multi-component diffusive mass transport is generally quantified by means of the Maxwell-Stefan diffusion coefficients when using molecular simulations. These coefficients can be related to the Fick diffusion coefficients using the thermodynamic correction factor matrix, which requires to run several simulations to estimate all the elements of the matrix. In a recent work, Schnell et al. ["Thermodynamics of small systems embedded in a reservoir: A detailed analysis of finite size effects," Mol. Phys. 110, 1069-1079 (2012)] developed an approach to determine the full matrix of thermodynamic factors from a single simulation in bulk. This approach relies on finite size effects of small systems on the density fluctuations. We present here an extension of their work for inhomogeneous Lennard Jones fluids confined in slit pores. We first verified this extension by cross validating the results obtained from this approach with the results obtained from the simulated adsorption isotherms, which allows to determine the thermodynamic factor in porous medium. We then studied the effects of the pore width (from 1 to 15 molecular sizes), of the solid-fluid interaction potential (Lennard Jones 9-3, hard wall potential) and of the reduced fluid density (from 0.1 to 0.7 at a reduced temperature T* = 2) on the thermodynamic factor. The deviation of the thermodynamic factor compared to its equivalent bulk value decreases when increasing the pore width and becomes insignificant for reduced pore width above 15. We also found that the thermodynamic factor is sensitive to the magnitude of the fluid-fluid and solid-fluid interactions, which softens or exacerbates the density fluctuations.

NASA Telescopes Join Forces To Observe Unprecedented Explosion

NASA Image and Video Library

2017-12-08

NASA image release April 6, 2011 Images from Swift's Ultraviolet/Optical (white, purple) and X-ray telescopes (yellow and red) were combined in this view of GRB 110328A. The blast was detected only in X-rays, which were collected over a 3.4-hour period on March 28. Credit: NASA/Swift/Stefan Immler NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location. Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours. Although research is ongoing, astronomers say that the unusual blast likely arose when a star wandered too close to its galaxy's central black hole. Intense tidal forces tore the star apart, and the infalling gas continues to stream toward the hole. According to this model, the spinning black hole formed an outflowing jet along its spin axis. A powerful blast of X- and gamma rays is seen if this jet is pointed in our direction. To read more go to: www.nasa.gov/topics/universe/features/star-disintegration... NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Magnetic permeability as a predictor of the artefact size caused by orthodontic appliances at 1.5 T magnetic resonance imaging.

PubMed

Blankenstein, Felix H; Asbach, Patrick; Beuer, Florian; Glienke, Johannes; Mayer, Stefan; Zachriat, Christine

2017-01-01

Artefacts caused by orthodontic attachments limit the diagnostic value and lead to removal of these appliances before magnetic resonance imaging. Magnetic permeability can predict the artefact size. There is no standardised approach to determine the permeability of such attachments. The aim was to establish a reliable approach to determine artefact size caused by orthodontic attachments at 1.5 T MRI. Artefact radii of 21 attachments were determined applying two prevalent sequences of the head and neck region (turbo spin echo and gradient echo). The instrument Ferromaster (Stefan Mayer Instruments, Dinslaken) is approved for permeability measurements of objects with a minimum size (d = 20 mm, h = 5 mm). Eleven small test specimens of known permeability between 1.003 and 1.431 were produced. They are slightly larger than the orthodontic attachments. Their artefacts were measured and cross tabulated against the permeability. The resulting curve was used to compare the orthodontic attachments with the test bodies. Steel caused a wide range of artefact size of 10-74 mm subject to their permeability. Titanium, cobalt-chromium and ceramic materials produced artefact radii up to 20 mm. Measurement of artefacts of the test bodies revealed an interrelationship according to a root function. The artefact size of all brackets was below that root function. The permeability can be reliably assessed by conventional measurement devices and the artefact size can be predicted. The radiologist is able to decide whether or not the orthodontic attachments should be removed. This study clarifies whether an orthodontic appliance must be removed before taking an MRI.

The boundary condition for vertical velocity and its interdependence with surface gas exchange

NASA Astrophysics Data System (ADS)

Kowalski, Andrew S.

2017-07-01

The law of conservation of linear momentum is applied to surface gas exchanges, employing scale analysis to diagnose the vertical velocity (w) in the boundary layer. Net upward momentum in the surface layer is forced by evaporation (E) and defines non-zero vertical motion, with a magnitude defined by the ratio of E to the air density, as w = E/ρ. This is true even right down at the surface where the boundary condition is w|0 = E/ρ|0 (where w|0 and ρ|0 represent the vertical velocity and density of air at the surface). This Stefan flow velocity implies upward transport of a non-diffusive nature that is a general feature of the troposphere but is of particular importance at the surface, where it assists molecular diffusion with upward gas migration (of H2O, for example) but opposes that of downward-diffusing species like CO2 during daytime. The definition of flux-gradient relationships (eddy diffusivities) requires rectification to exclude non-diffusive transport, which does not depend on scalar gradients. At the microscopic scale, the role of non-diffusive transport in the process of evaporation from inside a narrow tube - with vapour transport into an overlying, horizontal airstream - was described long ago in classical mechanics and is routinely accounted for by chemical engineers, but has been neglected by scientists studying stomatal conductance. Correctly accounting for non-diffusive transport through stomata, which can appreciably reduce net CO2 transport and marginally boost that of water vapour, should improve characterisations of ecosystem and plant functioning.

An integrated structure- and system-based framework to identify new targets of metabolites and known drugs

PubMed Central

Naveed, Hammad; Hameed, Umar S.; Harrus, Deborah; Bourguet, William; Arold, Stefan T.; Gao, Xin

2015-01-01

Motivation: The inherent promiscuity of small molecules towards protein targets impedes our understanding of healthy versus diseased metabolism. This promiscuity also poses a challenge for the pharmaceutical industry as identifying all protein targets is important to assess (side) effects and repositioning opportunities for a drug. Results: Here, we present a novel integrated structure- and system-based approach of drug-target prediction (iDTP) to enable the large-scale discovery of new targets for small molecules, such as pharmaceutical drugs, co-factors and metabolites (collectively called ‘drugs’). For a given drug, our method uses sequence order–independent structure alignment, hierarchical clustering and probabilistic sequence similarity to construct a probabilistic pocket ensemble (PPE) that captures promiscuous structural features of different binding sites on known targets. A drug’s PPE is combined with an approximation of its delivery profile to reduce false positives. In our cross-validation study, we use iDTP to predict the known targets of 11 drugs, with 63% sensitivity and 81% specificity. We then predicted novel targets for these drugs—two that are of high pharmacological interest, the peroxisome proliferator-activated receptor gamma and the oncogene B-cell lymphoma 2, were successfully validated through in vitro binding experiments. Our method is broadly applicable for the prediction of protein-small molecule interactions with several novel applications to biological research and drug development. Availability and implementation: The program, datasets and results are freely available to academic users at http://sfb.kaust.edu.sa/Pages/Software.aspx. Contact: xin.gao@kaust.edu.sa and stefan.arold@kaust.edu.sa Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26286808

Measuring and modeling near-surface reflected and emitted radiation fluxes at the FIFE site

NASA Technical Reports Server (NTRS)

Blad, Blaine L.; Walter-Shea, Elizabeth A.; Starks, Patrick J.; Vining, Roel C.; Hays, Cynthia J.; Mesarch, Mark A.

1990-01-01

Information is presented pertaining to the measurement and estimation of reflected and emitted components of the radiation balance. Information is included about reflectance and transmittance of solar radiation from and through the leaves of some grass and forb prairie species, bidirectional reflectance from a prairie canopy is discussed and measured and estimated fluxes are described of incoming and outgoing longwave and shortwave radiation. Results of the study showed only very small differences in reflectances and transmittances for the adaxial and abaxial surfaces of grass species in the visible and infrared wavebands, but some differences in the infrared wavebands were noted for the forbs. Reflectance from the prairie canopy changed as a function of solar and view zenith angles in the solar principal plane with definite asymmetry about nadir. The surface temperature of prairie canopies was found to vary by as much as 5 C depending on view zenith and azimuth position and on the solar azimuth. Aerodynamic temperature calculated from measured sensible heat fluxes ranged from 0 to 3 C higher than nadir-viewed temperatures. Models were developed to estimate incoming and reflected shortwave radiation from data collected with a Barnes Modular Multiband Radiometer. Several algorithms for estimating incoming longwave radiation were evaluated and compared to actual measures of that parameter. Net radiation was calculated using the estimated components of the shortwave radiation streams, determined from the algorithms developed, and from the longwave radiation streams provided by the Brunt, modified Deacon, and the Stefan-Boltzmann models. Estimates of net radiation were compared to measured values and found to be within the measurement error of the net radiometers used in the study.

Influence of Liquid Structure on Fickian Diffusion in Binary Mixtures of n-Hexane and Carbon Dioxide Probed by Dynamic Light Scattering, Raman Spectroscopy, and Molecular Dynamics Simulations.

PubMed

Klein, Tobias; Wu, Wenchang; Rausch, Michael Heinrich; Giraudet, Cédric; Koller, Thomas M; Fröba, Andreas Paul

2018-06-11

This study contributes to a fundamental understanding how the liquid structure in a model system consisting of weakly associative n-hexane ( n-C 6 H 14 ) and carbon dioxide (CO 2 ) influences the Fickian diffusion process. For this, the benefits of light scattering experiments and molecular dynamics (MD) simulations at macroscopic thermodynamic equilibrium were combined synergistically. Our reference Fickian diffusivities measured by dynamic light scattering (DLS) revealed an unusual trend with increasing CO 2 mole fractions up to a CO 2 concentration of about 70 mol%, which agrees with our simulation results. The molecular impacts on the Fickian diffusion were analyzed by MD simulations, where kinetic contributions related to the Maxwell-Stefan (MS) diffusivity and structural contributions quantified by the thermodynamic factor were studied separately. Both the MS diffusivity and the thermodynamic factor indicate the deceleration of Fickian diffusion compared to an ideal mixture behavior. Computed radial distribution functions as well as a significant blue-shift of the CH-stretching modes of n-C 6 H 14 identified by Raman spectroscopy show that the slowing-down of the diffusion is caused by a structural organization in the binary mixtures over a broad concentration range in the form of self-associated n-C 6 H 14 and CO 2 domains. These networks start to form close to the infinite dilution limits and seem to have their largest extent at a solute-solvent transition point at about 70 mol% of CO 2 . The current results not only improve the general understanding of mass diffusion in liquids, but also serve to develop sound prediction models for Fick diffusivities.

The effective Tolman temperature in curved spacetimes

NASA Astrophysics Data System (ADS)

Kim, Wontae

We review a recently proposed effective Tolman temperature and present its applications to various gravitational systems. In the Unruh state for the evaporating black holes, the free-fall energy density is found to be negative divergent at the horizon, which is in contrast to the conventional calculations performed in the Kruskal coordinates. We resolve this conflict by invoking that the Kruskal coordinates could be no longer proper coordinates at the horizon. In the Hartle-Hawking-Israel state, despite the negative finite proper energy density at the horizon, the Tolman temperature is divergent there due to the infinite blueshift of the Hawking temperature. However, a consistent Stefan-Boltzmann law with the Hawking radiation shows that the effective Tolman temperature is eventually finite everywhere and the equivalence principle is surprisingly restored at the horizon. Then, we also show that the firewall necessarily emerges out of the Unruh vacuum, so that the Tolman temperature in the evaporating black hole is naturally divergent due to the infinitely blueshifted negative ingoing flux crossing the horizon, whereas the outgoing Hawking radiation characterized by the effective Tolman temperature indeed originates from the quantum atmosphere, not just at the horizon. So, the firewall and the atmosphere for the Hawking radiation turn out to be compatible, once we discard the fact that the Hawking radiation in the Unruh state originates from the infinitely blueshifted outgoing excitations at the horizon. Finally, as a cosmological application, the initial radiation energy density in warm inflation scenarios has been assumed to be finite when inflation starts. We successfully find the origin of the nonvanishing initial radiation energy density in the warm inflation by using the effective Tolman temperature.

Determination of the thermodynamic correction factor of fluids confined in nano-metric slit pores from molecular simulation

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

Collell, Julien; Galliero, Guillaume, E-mail: guillaume.galliero@univ-pau.fr

2014-05-21

The multi-component diffusive mass transport is generally quantified by means of the Maxwell-Stefan diffusion coefficients when using molecular simulations. These coefficients can be related to the Fick diffusion coefficients using the thermodynamic correction factor matrix, which requires to run several simulations to estimate all the elements of the matrix. In a recent work, Schnell et al. [“Thermodynamics of small systems embedded in a reservoir: A detailed analysis of finite size effects,” Mol. Phys. 110, 1069–1079 (2012)] developed an approach to determine the full matrix of thermodynamic factors from a single simulation in bulk. This approach relies on finite size effectsmore » of small systems on the density fluctuations. We present here an extension of their work for inhomogeneous Lennard Jones fluids confined in slit pores. We first verified this extension by cross validating the results obtained from this approach with the results obtained from the simulated adsorption isotherms, which allows to determine the thermodynamic factor in porous medium. We then studied the effects of the pore width (from 1 to 15 molecular sizes), of the solid-fluid interaction potential (Lennard Jones 9-3, hard wall potential) and of the reduced fluid density (from 0.1 to 0.7 at a reduced temperature T* = 2) on the thermodynamic factor. The deviation of the thermodynamic factor compared to its equivalent bulk value decreases when increasing the pore width and becomes insignificant for reduced pore width above 15. We also found that the thermodynamic factor is sensitive to the magnitude of the fluid-fluid and solid-fluid interactions, which softens or exacerbates the density fluctuations.« less

Simultaneous measurement of monocomponent droplet temperature/refractive index, size and evaporation rate with phase rainbow refractometry

NASA Astrophysics Data System (ADS)

Wu, Yingchun; Crua, Cyril; Li, Haipeng; Saengkaew, Sawitree; Mädler, Lutz; Wu, Xuecheng; Gréhan, Gérard

2018-07-01

The accurate measurements of droplet temperature, size and evaporation rate are of great importance to characterize the heat and mass transfer during evaporation/condensation processes. The nanoscale size change of a micron-sized droplet exactly describes its transient mass transfer, but is difficult to measure because it is smaller than the resolutions of current size measurement techniques. The Phase Rainbow Refractometry (PRR) technique is developed and applied to measure droplet temperature, size and transient size changes and thereafter evaporation rate simultaneously. The measurement principle of PRR is theoretically derived, and it reveals that the phase shift of the time-resolved ripple structures linearly depends on, and can directly yield, nano-scale size changes of droplets. The PRR technique is first verified through the simulation of rainbows of droplets with changing size, and results show that PRR can precisely measure droplet refractive index, absolute size, as well as size change with absolute and relative errors within several nanometers and 0.6%, respectively, and thus PRR permits accurate measurements of transient droplet evaporation rates. The evaporations of flowing single n-nonane droplet and mono-dispersed n-heptane droplet stream are investigated by two PRR systems with a high speed linear CCD and a low speed array CCD, respectively. Their transient evaporation rates are experimentally determined and quantitatively agree well with the theoretical values predicted by classical Maxwell and Stefan-Fuchs models. With the demonstration of evaporation rate measurement of monocomponent droplet in this work, PRR is an ideal tool for measurements of transient droplet evaporation/condensation processes, and can be extended to multicomponent droplets in a wide range of industrially-relevant applications.

[Figures of first laureates of the Wiktor Dega medal (XXXVII Jubilee Congress of Polish Orthopaedic and Traumatologic Society, 10-13 September 2008)].

PubMed

Nowakowski, Andrzej; Rapała, Kazimierz

2008-01-01

Figures of two outstanding orthopaedists Professor Stefan Malawski and Professor Jerzy Król rewarded with the medal of the name of Wiktor Degi were described. The medal is being granted by the Chapter of the Medal as regarding for outstanding achievements for the Polish and world orthopaedics and rehabilitation. Profesor Stefan Kazimierz Malawski was born 26. 12. 1920 in the Vilnius area. In Vilnius he stated his medical studies, which he continued in Lwow and graduated in 1946 at the Marie Curie Skłodowska in Lublin. Professor Malawski's main field of interest were related to the problems related to tuberculosis of bones and joints and trauma of the lumbar and cervical spine. In the problems of bone tuberculosis he remains an unquestioned authority in Poland. His deep understanding of these clinical problems can be found in his text-book "Tuberculosis of bones and joints", which was printed in 1976. The information pertaining diagnosis and surgical treatment remain extremely valuable today. Another field of interest of Professor Malawski are pathologies of the spine. Disc disease, neoplasms of the spine, spinal stenosis and infections of the spine, spondylolisthesis are among many of his interests. This very wide field of interest can be dound in his 3 tome publication Spondyloorthopedics. His 166 papars printed in Poland and abroad bear proof of the Professors wide field of interest and deep knowledge. Professor Malawski was the first surgeon in Poland to perform surgery on the front elements of the spine in tuberculotic paraplegia. In 1958 he implemented surgical treatment of spine tumor--both primary and metastatic, by resecting them and stabilizing the spine with grafts. In the early 70's he focused on spinal stenosis. In the years 1982-1986 he was the Chairman of the Board of the Polish Orthopedic and Trauma Society. Professor Malawski introdued a modern set of Rules and Regulations, greatly simplifying the decision making process during General assemblies

Daytime Utilization of a University Observatory for Laboratory Instruction

NASA Astrophysics Data System (ADS)

Mattox, J. R.

2006-08-01

Scheduling convenience provides a strong incentive to fully explore effective utilization of educational observatories during daylight hours. I present two compelling daytime student activities that I developed at the Observatory at Fayetteville State University. My Introductory Astronomy Laboratory classes pursue these as separate investigations. My Physical Science classes complete both in a single lab period of 110 minutes duration. Both of these activities are also appropriate for High School student investigators, and could be used as demonstrations for younger students. Daylight Observation of Venus. With a clear sky, and when its elongation exceeds ~20˚, Venus is readily apparent in the daytime sky once a telescope is pointed at it. This is accomplished either with a digital pointing system, or with setting circles on a polar-aligned mount using the Sun to initialize the RA circle. Using the telescope pointing as a reference, it is also possible under optimal circumstances for students to see Venus in the daytime sky with naked eyes. Students are asked to write about the circumstances that made it possible to see Venus. Educational utilization of daytime observations of the Moon, Jupiter, Saturn, and the brightest stars are also discussed. Using a CCD Camera to Determine the Temperature of a Sunspot. After my students view the Sun with Eclipse Glasses and in projection using a 3-inch refractor, they analyze a CCD image of a sunspot (which they obtain if possible) to determine the ratio of its surface intensity relative to the normal solar surface. They then use the Stefan-Boltzmann law (usually with some coaching) to determine the sunspot temperature given the nominal surface temperature of the Sun. Appropriate safety precautions are presented given the hazards of magnified sunlight. Mitigation of dome seeing during daylight hours is discussed.

Candle flames in microgravity

NASA Technical Reports Server (NTRS)

Dietrich, D. L.; Ross, H. D.; Tien, J. S.

1995-01-01

The candle flame in both normal and microgravity is non-propagating. In microgravity, however, the candle flame is also non-convective where (excepting Stefan flow) pure diffusion is the only transport mode. It also shares many characteristics with another classical problem, that of isolated droplet combustion. Given their qualitatively similar flame shapes and the required heat feedback to condensed-phase fuels, the gas-phase flow and temperature fields should be relatively similar for a droplet and a candle in reduced gravity. Unless the droplet diameter is maintained somehow through non-intrusive replenishment of fuel, the quasi-steady burning characteristics of a droplet can be maintained for only a few seconds. In contrast, the candle flame in microgravity may achieve a nearly steady state over a much longer time and is therefore ideal for examining a number of combustion-related phenomena. In this paper, we examine candle flame behavior in both short-duration and long-duration, quiescent, microgravity environments. Interest in this type of flame, especially 'candle flames in weightlessness', is demonstrated by very frequent public inquiries. The question is usually posed as 'will a candle flame burn in zero gravity', or, 'will a candle burn indefinitely (or steadily) in zero gravity in a large volume of quiescent air'. Intuitive speculation suggests to some that, in the absence of buoyancy, the accumulation of products in the vicinity of the flame will cause flame extinction. The classical theory for droplet combustion with its spherically-shaped diffusion flame, however, shows that steady combustion is possible in the absence of buoyancy if the chemical kinetics are fast enough. Previous experimental studies of candle flames in reduced and microgravity environments showed the flame could survive for at least 5 seconds, but did not reach a steady state in the available test time.

Functional Zoning and Urban Development Tendencies of Bucharest City/Romania

NASA Astrophysics Data System (ADS)

Armas, Iuliana; Dumitrascu, Silvia

2010-05-01

Any form of urban development policy for environmental management should be based on the differentiation of the structure of a territory that can be found in the shape of functional zoning. Identifying the patterns of morphological structure of the urban space can provide essential clues concerning the proper measures to take into consideration during the activity of urban planning. In this sense, the Bucharest municipality study case provides the example of a dynamic urban space with a complex and distinctive evolutionary structure. The aim of the study is to set out the main events that shaped the Bucharest city space and the patterns resulted from their impact at the functional level of the Romanian capital. In order to identify the development tendencies of the Bucharest municipality, a series of aspects concerning urban morphology should be highlighted that reveal the impact of the socio-economical policies at the structural level of the territory. In this sense, three images of the urban space stand out, representative for the period when they materialized: the Post-Byzantine (XV-XVIII), the Fanariot (XVIII) and the Modern periods (XIX-XX). The corresponding cartographic documents analyzed are: the Franz Purcel Plan (dated 1789), the Romanian Guide Print Plan and, respectively, the AGC Busman Print Plan. The analysis reveals three distinctive morphological types: radial-concentric in the 17th century, polynuclear in the 18th century, leading to the mixed character in the Modern period. The latest trait of the urban territory is based on the concentric character of the street network (three circles were identified at the level of the capital city that point out the evolution of the urban space: Dacia bv-Mircea Vulcanescu, Stefan cel Mare bv-Iancu de Hunedoara and the last circle outlined by the ring road) and the presence of multiple nuclei that accumulate the commercial, administrative and business functions of the city.

Analytical solutions for combined close-contact and natural convection melting in horizontal cylindrical heat storage capsule

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

Saitoh, T.S.; Hoshi, A.

1998-07-01

Melting and solidification of a phase change material (PCM) in a capsule is of practical importance in latent heat thermal energy storage (LHTES) systems which are considered to be very promising to reduce a peak demand of electricity in the summer season and carbon dioxide (CO{sub 2}) emissions. Two melting modes are involved in melting of capsules. One is close-contact melting between the solid bulk and the capsule wall, and another is natural convection melting in the liquid region. Close-contact melting processes for a single enclosure have been solved using several numerical methods (e.g., Saitoh and Kato (1994)). In additionmore » close-contact melting heat transfer characteristics including melt flow in the liquid film under inner wall temperature distribution were analyzed and simple approximate equations were already presented by Saitoh and Hoshi (1997). The effects of Stefan number and variable temperature profile etc. were clarified in detail. And the melting velocity of the solid bulk under various conditions was also studied theoretically. In addition the effects of variable inner wall temperature on molten mass fraction were investigated. The present paper reports analytical solutions for combined close-contact and natural convection melting in horizontal cylindrical capsule. Moreover, natural convection melting in the liquid region were analyzed in this report. The upper interface shape of the solid bulk is approximated by a circular arc throughout the melting process. For the sake of verification, close-contact melting heat-transfer characteristics including natural convection in the liquid region were studied experimentally. Apparent shift of upper solid-liquid interface is good agreement with the experiment. The present simple approximate solutions will be useful to facilitate designing of the practical capsule bed LHTES systems.« less

Quantitative Assessment of the Integrated Response in Global Heat and Moisture Budgets to Changing Solar Irradiance

NASA Technical Reports Server (NTRS)

White, Warren B.; Cayan, Daniel R.; Dettinger, Michael; Sharber, James (Technical Monitor)

2001-01-01

Earlier, we found time sequences of basin- and global-average upper ocean temperature (that is, diabatic heat storage above the main pycnocline) for 40 years from 1955-1994 and of sea surface temperature for 95 years from 1900-1994 associated with changes in the Sun's radiative forcing on decadal and interdecadal timescales, lagging by 10 deg.- 30 deg. of phase and confined to the upper 60-120 m. Yet, the observed changes in upper ocean temperature (approx. 0.1 K) were approximately twice those expected from the Stefan-Boltzmann black-body radiation law for the Earth's surface, with phase lags (0 deg. to 30 deg. of phase) much shorter than the 90 deg. phase shift expected as well. Moreover, White et al. (1997, 1998) found the Earth's global decadal mode in covarying SST and SLP anomalies phase locked to the decadal signal in the Sun's irradiance. Yet, Allan (2000) found this decadal signal also characterized by patterns similar to those observed on biennial and interannual time scales; that is, the Troposphere Biennial Oscillation (TBO) and the El Nino and the Southern Oscillation (ENSO). This suggested that small changes in the Sun's total irradiance could excite this global decadal mode in the Earth's ocean-atmosphere-terrestrial system similar to those excited internally on biennial and interannual period scales. This is a significant finding, proving that energy budget models (that is, models based on globally-averaged radiation balances) yield unrealistic responses. Thus, the true response must include positive and negative feedbacks in the Earth's ocean-atmosphere-terrestrial system as its internal mode (that is, the natural mode of the system) respond in damped resonance to quasi-periodic decadal changes in the Sun's irradiance. Moreover, these responses are not much different from those occurring internally on biennial and interannual period scales.

Hemoglobin encapsulation in vesicles retards NO and CO binding and O2 release when perfused through narrow gas-permeable tubes.

PubMed

Sakai, Hiromi; Okuda, Naoto; Sato, Atsushi; Yamaue, Tatsuya; Takeoka, Shinji; Tsuchida, Eishun

2010-03-01

Intravenous administration of cell-free Hb induces vasoconstriction and circulatory disorders, presumably because of the intrinsic affinities to endogenous nitric oxide (NO) and carbon monoxide (CO) as vasorelaxation factors and because of the facilitated O(2) release that might induce autoregulatory vasoconstriction. We examined these gas reactions when Hb-containing solutions of four kinds were perfused through artificial narrow tubes at a practical Hb concentration (10 g/dl). Purified Hb solution, polymerized bovine Hb (Poly(B)Hb), encapsulated Hb [Hb-vesicles (HbV), 279 nm], and red blood cells (RBCs) were perfused through a gas-permeable narrow tube (25 microm inner diameter) at 1 mm/s centerline velocity. The level of reactions was determined microscopically based on the visible-light absorption spectrum of Hb. When the tube was immersed in NO and CO atmospheres, both NO binding and CO binding of deoxygenated Hb (deoxy-Hb) and Poly(B)Hb in the tube was faster than those of HbV and RBCs, and HbV and RBCs showed almost identical binding rates. When the tube was immersed in a N(2) atmosphere, oxygenated Hb and Poly(B)Hb showed much faster O(2) release than did HbV and RBCs. Poly(B)Hb showed a faster reaction than Hb because of the lower O(2) affinity of Poly(B)Hb than Hb. The diffusion process of the particles was simulated using Navier-Stokes and Maxwell-Stefan equations. Results clarified that small Hb (6 nm) diffuses laterally and mixes rapidly. However, the large-dimension HbV shows no such rapid diffusion. The purely physicochemical differences in diffusivity of the particles and the resulting reactivity with gas molecules are one factor inducing biological vasoconstriction of Hb-based oxygen carriers.

Transport properties of partially ionized and unmagnetized plasmas.

PubMed

Magin, Thierry E; Degrez, Gérard

2004-10-01

This work is a comprehensive and theoretical study of transport phenomena in partially ionized and unmagnetized plasmas by means of kinetic theory. The pros and cons of different models encountered in the literature are presented. A dimensional analysis of the Boltzmann equation deals with the disparity of mass between electrons and heavy particles and yields the epochal relaxation concept. First, electrons and heavy particles exhibit distinct kinetic time scales and may have different translational temperatures. The hydrodynamic velocity is assumed to be identical for both types of species. Second, at the hydrodynamic time scale the energy exchanged between electrons and heavy particles tends to equalize both temperatures. Global and species macroscopic fluid conservation equations are given. New constrained integral equations are derived from a modified Chapman-Enskog perturbative method. Adequate bracket integrals are introduced to treat thermal nonequilibrium. A symmetric mathematical formalism is preferred for physical and numerical standpoints. A Laguerre-Sonine polynomial expansion allows for systems of transport to be derived. Momentum, mass, and energy fluxes are associated to shear viscosity, diffusion coefficients, thermal diffusion coefficients, and thermal conductivities. A Goldstein expansion of the perturbation function provides explicit expressions of the thermal diffusion ratios and measurable thermal conductivities. Thermal diffusion terms already found in the Russian literature ensure the exact mass conservation. A generalized Stefan-Maxwell equation is derived following the method of Kolesnikov and Tirskiy. The bracket integral reduction in terms of transport collision integrals is presented in Appendix for the thermal nonequilibrium case. A simple Eucken correction is proposed to deal with the internal degrees of freedom of atoms and polyatomic molecules, neglecting inelastic collisions. The authors believe that the final expressions are

Analysis of non-equilibrium phenomena in inductively coupled plasma generators

NASA Astrophysics Data System (ADS)

Zhang, W.; Lani, A.; Panesi, M.

2016-07-01

This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) A Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.

Response of seasonal soil freeze depth to climate change across China

NASA Astrophysics Data System (ADS)

Peng, Xiaoqing; Zhang, Tingjun; Frauenfeld, Oliver W.; Wang, Kang; Cao, Bin; Zhong, Xinyue; Su, Hang; Mu, Cuicui

2017-05-01

The response of seasonal soil freeze depth to climate change has repercussions for the surface energy and water balance, ecosystems, the carbon cycle, and soil nutrient exchange. Despite its importance, the response of soil freeze depth to climate change is largely unknown. This study employs the Stefan solution and observations from 845 meteorological stations to investigate the response of variations in soil freeze depth to climate change across China. Observations include daily air temperatures, daily soil temperatures at various depths, mean monthly gridded air temperatures, and the normalized difference vegetation index. Results show that soil freeze depth decreased significantly at a rate of -0.18 ± 0.03 cm yr-1, resulting in a net decrease of 8.05 ± 1.5 cm over 1967-2012 across China. On the regional scale, soil freeze depth decreases varied between 0.0 and 0.4 cm yr-1 in most parts of China during 1950-2009. By investigating potential climatic and environmental driving factors of soil freeze depth variability, we find that mean annual air temperature and ground surface temperature, air thawing index, ground surface thawing index, and vegetation growth are all negatively associated with soil freeze depth. Changes in snow depth are not correlated with soil freeze depth. Air and ground surface freezing indices are positively correlated with soil freeze depth. Comparing these potential driving factors of soil freeze depth, we find that freezing index and vegetation growth are more strongly correlated with soil freeze depth, while snow depth is not significant. We conclude that air temperature increases are responsible for the decrease in seasonal freeze depth. These results are important for understanding the soil freeze-thaw dynamics and the impacts of soil freeze depth on ecosystem and hydrological process.

Numerical investigation of melting and solidification processes in modified surface layers of metal at induction heating

NASA Astrophysics Data System (ADS)

Shchukin, V. G.; Popov, V. N.

2017-10-01

One of the perspective ways to improve the operational properties of parts of machines during induction treatment of their surfaces is the modification of the melt by specially prepared nanoscale particles of refractory compounds (carbides, nitrides, carbonitrides, etc.). This approach allows us to increase the number of crystallization centers and to refine the structural components of the solidified metal. The resulting high dispersity and homogeneity of crystalline grains favorably affect the quality of the treated surfaces. 3D numerical simulation of thermophysical processes in the modification of the surface layer of metal in a moving substrate was carried out. It is assumed that the surface of the substrate is covered with a layer of specially prepared nanoscale particles of a refractory compound, which, upon penetration into the melt, are uniformly distributed in it. The possibility of applying a high-frequency electromagnetic field of high power for heating and melting of a metal (iron) for the purpose of its subsequent modification is investigated. The distribution of electromagnetic energy in the metal is described by empirical formulas. Melting of the metal is considered in the Stefan approximation, and upon solidification it is assumed that all nanoparticles serve as centers for volume-sequential crystallization. Calculations were carried out with the following parameters: specific power p0 = 35 and 40 kW/cm2 at frequency f = 440 and 1200 kHz, the substrate velocity V = 0.5-2.5 cm/s, the nanoparticles' size is 50 nm and concentration Np = 2.0 . 109 cm-3. Based on the results obtained in a quasi-stationary formulation, the distribution of the temperature field, the dimensions of the melting and crystallization zones, the change in the solid fraction in the two-phase zone, the area of the treated substrate surface, depending on the speed of its movement and induction heating characteristics were estimated.

Imaging Total Stations - Modular and Integrated Concepts

NASA Astrophysics Data System (ADS)

Hauth, Stefan; Schlüter, Martin

2010-05-01

Keywords: 3D-Metrology, Engineering Geodesy, Digital Image Processing Initialized in 2009, the Institute for Spatial Information and Surveying Technology i3mainz, Mainz University of Applied Sciences, forces research towards modular concepts for imaging total stations. On the one hand, this research is driven by the successful setup of high precision imaging motor theodolites in the near past, on the other hand it is pushed by the actual introduction of integrated imaging total stations to the positioning market by the manufacturers Topcon and Trimble. Modular concepts for imaging total stations are manufacturer independent to a large extent and consist of a particular combination of accessory hardware, software and algorithmic procedures. The hardware part consists mainly of an interchangeable eyepiece adapter offering opportunities for digital imaging and motorized focus control. An easy assembly and disassembly in the field is possible allowing the user to switch between the classical and the imaging use of a robotic total station. The software part primarily has to ensure hardware control, but several level of algorithmic support might be added and have to be distinguished. Algorithmic procedures allow to reach several levels of calibration concerning the geometry of the external digital camera and the total station. We deliver insight in our recent developments and quality characteristics. Both the modular and the integrated approach seem to have its individual strengths and weaknesses. Therefore we expect that both approaches might point at different target applications. Our aim is a better understanding of appropriate applications for robotic imaging total stations. First results are presented. Stefan Hauth, Martin Schlüter i3mainz - Institut für Raumbezogene Informations- und Messtechnik FH Mainz University of Applied Sciences Lucy-Hillebrand-Straße 2, 55128 Mainz, Germany

Surface 3D nanostructuring by tightly focused laser pulse: simulations by Lagrangian code and molecular dynamics

NASA Astrophysics Data System (ADS)

Inogamov, Nail A.; Zhakhovsky, Vasily V.

2016-02-01

There are many important applications in which the ultrashort diffraction-limited and therefore tightly focused laser pulses irradiates metal films mounted on dielectric substrate. Here we present the detailed picture of laser peeling and 3D structure formation of the thin (relative to a depth of a heat affected zone in the bulk targets) gold films on glass substrate. The underlying physics of such diffraction-limited laser peeling was not well understood previously. Our approach is based on a physical model which takes into consideration the new calculations of the two-temperature (2T) equation of state (2T EoS) and the two-temperature transport coefficients together with the coupling parameter between electron and ion subsystems. The usage of the 2T EoS and the kinetic coefficients is required because absorption of an ultrashort pulse with duration of 10-1000 fs excites electron subsystem of metal and transfers substance into the 2T state with hot electrons (typical electron temperatures 1-3 eV) and much colder ions. It is shown that formation of submicrometer-sized 3D structures is a result of the electron-ion energy transfer, melting, and delamination of film from substrate under combined action of electron and ion pressures, capillary deceleration of the delaminated liquid metal or semiconductor, and ultrafast freezing of molten material. We found that the freezing is going in non-equilibrium regime with strongly overcooled liquid phase. In this case the Stefan approximation is non-applicable because the solidification front speed is limited by the diffusion rate of atoms in the molten material. To solve the problem we have developed the 2T Lagrangian code including all this reach physics in. We also used the high-performance combined Monte- Carlo and molecular dynamics code for simulation of surface 3D nanostructuring at later times after completion of electron-ion relaxation.

R&D comes to services. Bank of America's pathbreaking experiments.

PubMed

Thomke, Stefan

2003-04-01

At the heart of business today lies a dilemma: Our economy is increasingly dependent on services, yet our innovation processes remain oriented toward products. Indeed, we have well-tested, scientific methods for developing and refining manufactured goods, but many of them don't seem applicable to the world of services. In this article, Harvard Business School professor Stefan Thomke points out the challenges of applying the discipline of formal R&D processes to services: Because a service often exists only in the moment of its delivery to a customer, it is difficult to isolate in a traditional laboratory. And since many services are tailored to individual buyers at the point of purchase, they can't be tested through large samples. As a result, experiments with new services are most useful when they are conducted live--with real customers engaged in real transactions. But live tests magnify the cost of failure; an experiment that doesn't work may harm customer relationships and even the brand. Given such challenges, it's no surprise that most service companies have not established rigorous, ongoing R&D processes, Thomke says. Here the author provides an in-depth look at a five-step process that Bank of America has used to create new service concepts for retail banking. The company has turned a set of its branches into, in effect, a laboratory where a corporate research team conducts service experiments with actual customers during regular business hours, compares results with those of control branches, and pinpoints attractive innovations for broader rollout. The author describes the program's workings, its successes, and the obstacles the bank faced. The effort reveals what a true R&D operation might look like inside a service business, he concludes.

Analytical Solution for Transport with Bimolecular Reactions in Fracture-Matrix Systems with Application to In-Situ Chemical Oxidation

NASA Astrophysics Data System (ADS)

Rajaram, H.; Arshadi, M.

2016-12-01

In-situ chemical oxidation (ISCO) is an effective strategy for remediation of DNAPL contamination in fractured rock. During ISCO, an oxidant (e.g. permanganate) is typically injected through fractures and is consumed by bimolecular reactions with DNAPLs such as TCE and natural organic matter in the fracture and the adjacent rock matrix. Under these conditions, moving reaction fronts form and propagate along the fracture and into the rock matrix. The propagation of these reaction fronts is strongly influenced by the heterogeneity/discontinuity across the fracture-matrix interface (advective transport dominates in the fractures, while diffusive transport dominates in the rock matrix). We present analytical solutions for the concentrations of the oxidant, TCE and natural organic matter; and the propagation of the reaction fronts in a fracture-matrix system. Our approximate analytical solutions assume advection and reaction dominate over diffusion/dispersion in the fracture and neglect the latter. Diffusion and reaction with both TCE and immobile natural organic matter in the rock matrix are considered. The behavior of the reaction-diffusion equations in the rock matrix is posed as a Stefan problem where the diffusing oxidant reacts with both diffusing (TCE) and immobile (natural organic matter) reductants. Our analytical solutions establish that the reaction fronts propagate diffusively (i.e. as the square root of time) in both the matrix and the fracture. Our analytical solutions agree very well with numerical simulations for the case of uniform advection in the fracture. We also present extensions of our analytical solutions to non-uniform flows in the fracture by invoking a travel-time transformation. The non-uniform flow solutions are relevant to field applications of ISCO. The approximate analytical solutions are relevant to a broad class of reactive transport problems in fracture-matrix systems where moving reaction fronts occur.

Analysis of non-equilibrium phenomena in inductively coupled plasma generators

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

Zhang, W.; Panesi, M., E-mail: mpanesi@illinois.edu; Lani, A.

This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) Amore » Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.« less

Internet Searches and Their Relationship to Cognitive Function in Older Adults: Cross-Sectional Analysis.

PubMed

Austin, Johanna; Hollingshead, Kristy; Kaye, Jeffrey

2017-09-06

engines. Participants averaged 3.08 words per search (SD 1.6) and 5.77 letters per word (SD 2.2). Individuals with higher cognitive function used more unique terms per search (beta=.39, P=.002) and employed less common terms in their searches (beta=1.39, P=.02). Cognitive function was not significantly associated with the length of the words used in the searches. These results suggest that early decline in cognitive function may be detected from the terms people search for when they use the Internet. By continuously tracking basic aspects of Internet search terms, it may be possible to detect cognitive decline earlier than currently possible, thereby enabling proactive treatment and intervention. ©Johanna Austin, Kristy Hollingshead, Jeffrey Kaye. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 06.09.2017.

["My first encounter with German urology (1937)". Stefan Wesolowski (1908-2009) - a source in the archives of the German Society for Urology from the oldest corresponding member and promoter of Polish-German relationships].

PubMed

Moll, F H; Krischel, M; Zajaczkowski, T; Rathert, P

2010-10-01

A source in the archives of the German Society of Urology gives us a vivid insight into the situation in Berlin during the 1930s from the perspective of a young Polish doctor, and presents the situation at one of the leading urology institutions of the time in Germany. Furthermore, we learn about the social situation in hospitals as well as the discourse and networking taking place in the scientific community at that time.

Analysis and reconstructed modelling of the debris flow event of the 21st of July 2012 of St. Lorenzen (Styria, Austira)

NASA Astrophysics Data System (ADS)

Janu, Stefan; Mehlhorn, Susanne; Moser, Markus

2013-04-01

Analysis and reconstructed modelling of the debris flow event of the 21st of July 2012 of St. Lorenzen (Styria, Austria) Authors: Stefan Janu, Susanne Mehlhorn, Markus Moser The village of St. Lorenzen, in the Styrian Palten valley is situated on the banks of the Lorenz torrent, in which a debris flow event occurred in the early morning hours of the 21st of July 2012, causing catastrophic damage to residential buildings and other infrastructural facilities. In the ministry-approved hazard zone map of 2009, the flood water discharge and bedload volume associated with a 150-year event was estimated at 34 m³/s and 25,000 m³ respectively for the 5.84 km² catchment area. The bedload transport capacity of the torrent was classified as ranging from 'heavy' to 'capable of producing debris flows'. The dominant process type of the mass movement event may be described as a fine-grained debris flow. The damage in the residential area of St.Lorenzen was caused by a debris flow pulse in the lower reach of the Lorenz torrent. This debris flow pulse was in turn caused by numerous landslides along the middle reaches of the torrent, some of which caused blockages, ultimately leading to an outburst event in the main torrent. Discharge cross-sections ranging from 65 - 90 m², and over 100 m² in a few instances, were measured upstream of the St. Lorenzen residential area. Back-calculations of velocities yielded an average debris flow velocity along the middle reaches of the torrent between 11 and 16 m/s. An average velocity of 9 m/s was calculated for the debris flow at the neck of the alluvial fan directly behind the center of the village. Due to both the high discharge values as well as to the height of the mass movement deposits, the natural hazard event of 21 July 2012 in St. Lorenzen is clearly to be described as having had an extreme intensity. A total of 67 buildings were damaged along the Lorenz torrent, 7 of were completely destroyed. According to the Austrian Service for

Multiple stationary solutions of an irradiated slab

NASA Astrophysics Data System (ADS)

Taylor, P. D.; Feltham, D. L.

2005-04-01

A mathematical model describing the heat budget of an irradiated medium is introduced. The one-dimensional form of the equations and boundary conditions are presented and analysed. Heat transport at one face of the slab occurs by absorption (and reflection) of an incoming beam of short-wave radiation with a fraction of this radiation penetrating into the body of the slab, a diffusive heat flux in the slab and a prescribed incoming heat flux term. The other face of the slab is immersed in its own melt and is considered to be a free surface. Here, temperature continuity is prescribed and evolution of the surface is determined by a Stefan condition. These boundary conditions are flexible enough to describe a range of situations such as a laser shining on an opaque medium, or the natural environment of polar sea ice or lake ice. A two-stream radiation model is used which replaces the simple Beer's law of radiation attenuation frequently used for semi-infinite domains. The stationary solutions of the governing equations are sought and it is found that there exists two possible stationary solutions for a given set of boundary conditions and a range of parameter choices. It is found that the existence of two stationary solutions is a direct result of the model of radiation absorption, due to its effect on the albedo of the medium. A linear stability analysis and numerical calculations indicate that where two stationary solutions exist, the solution corresponding to a larger thickness is always stable and the solution corresponding to a smaller thickness is unstable. Numerical simulations reveal that when there are two solutions, if the slab is thinner than the smaller stationary thickness it will melt completely, whereas if the slab is thicker than the smaller stationary thickness it will evolve toward the larger stationary thickness. These results indicate that other mechanisms (e.g. wave-induced agglomeration of crystals) are necessary to grow a slab from zero initial

Multiple network-constrained regressions expand insights into influenza vaccination responses.

PubMed

Avey, Stefan; Mohanty, Subhasis; Wilson, Jean; Zapata, Heidi; Joshi, Samit R; Siconolfi, Barbara; Tsang, Sui; Shaw, Albert C; Kleinstein, Steven H

2017-07-15

://bitbucket.org/kleinstein/logminer . steven.kleinstein@yale.edu or stefan.avey@yale.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

High CO2 emissions through porous media: Transport mechanisms and implications for flux measurement and fractionation

USGS Publications Warehouse

Evans, William C.; Sorey, M.L.; Kennedy, B.M.; Stonestrom, David A.; Rogie, J.D.; Shuster, D.L.

2001-01-01

Diffuse emissions of CO2 are known to be large around some volcanoes and hydrothermal areas. Accumulation-chamber measurements of CO2 flux are increasingly used to estimate the total magmatic or metamorphic CO2 released from such areas. To assess the performance of accumulation chamber systems at fluxes one to three orders of magnitude higher than normally encountered in soil respiration studies, a test system was constructed in the laboratory where known fluxes could be maintained through dry sand. Steady-state gas concentration profiles and fractionation effects observed in the 30-cm sand column nearly match those predicted by the Stefan-Maxwell equations, indicating that the test system was functioning successfully as a uniform porous medium. Eight groups of investigators tested their accumulation chamber equipment, all configured with continuous infrared gas analyzers (IRGA), in this system. Over a flux range of ~ 200-12,000 g m-2 day-1, 90% of their 203 flux measurements were 0-25% lower than the imposed flux with a mean difference of - 12.5%. Although this difference would seem to be within the range of acceptability for many geologic investigations, some potential sources for larger errors were discovered. A steady-state pressure gradient of -20 Pa/m was measured in the sand column at a flux of 11,200 g m-2 day-1. The derived permeability (50 darcies) was used in the dusty-gas model (DGM) of transport to quantify various diffusive and viscous flux components. These calculations were used to demonstrate that accumulation chambers, in addition to reducing the underlying diffusive gradient, severely disrupt the steady-state pressure gradient. The resultant diversion of the net gas flow is probably responsible for the systematically low flux measurements. It was also shown that the fractionating effects of a viscous CO2 efflux against a diffusive influx of air will have a major impact on some important geochemical indicators, such as N2/Ar, ??15N-N2, and 4He/22

Subduction zone decoupling/retreat modeling explains south Tibet (Xigaze) and other supra-subduction zone ophiolites and their UHP mineral phases

NASA Astrophysics Data System (ADS)

Butler, Jared P.; Beaumont, Christopher

2017-04-01

The plate tectonic setting in which proto-ophiolite 'oceanic' lithosphere is created remains controversial with a number of environments suggested. Recent opinions tend to coalesce around supra-subduction zone (SSZ) forearc extension, with a popular conceptual model in which the proto-ophiolite forms during foundering of oceanic lithosphere at the time of spontaneous or induced onset of subduction. This mechanism is favored in intra-oceanic settings where the subducting lithosphere is old and the upper plate is young and thin. We investigate an alternative mechanism; namely, decoupling of the subducting oceanic lithosphere in the forearc of an active continental margin, followed by subduction zone (trench) retreat and creation of a forearc oceanic rift basin, containing proto-ophiolite lithosphere, between the continental margin and the retreating subduction zone. A template of 2D numerical model experiments examines the trade-off between strength of viscous coupling in the lithospheric subduction channel and net slab pull of the subducting lithosphere. Three tectonic styles are observed: 1) C, continuous subduction without forearc decoupling; 2) R, forearc decoupling followed by rapid subduction zone retreat; 3) B, breakoff of subducting lithosphere followed by re-initiation of subduction and in some cases, forearc decoupling (B-R). In one case (BA-B-R; where BA denotes backarc) subduction zone retreat follows backarc rifting. Subduction zone decoupling is analyzed using frictional-plastic yield theory and the Stefan solution for the separation of plates containing a viscous fluid. The numerical model results are used to explain the formation of Xigaze group ophiolites, southern Tibet, which formed in the Lhasa terrane forearc, likely following earlier subduction and not necessarily during subduction initiation. Either there was normal coupled subduction before subduction zone decoupling, or precursor slab breakoff, subduction re-initiation and then decoupling

Citations Prize 2013

NASA Astrophysics Data System (ADS)

Cherry, Simon; Ruffle, Jon

2014-06-01

Physics in Medicine and Biology (PMB) awards its 'Citations Prize' to the authors of the original research paper that has received the most citations in the preceding five years (according to the Institute for Scientific Information (ISI)). The lead author of the winning paper is presented with the Rotblat Medal (named in honour of Professor Sir Joseph Rotblat, a Nobel Prize winner who also was the second—and longest serving—Editor of PMB, from 1961-1972). The winner of the 2013 Citations Prize for the paper which has received the most citations in the previous five years (2008-2012) is Figure. Figure. Four of the prize winning authors. From left to right: Thomas Istel (Philips), Jens-Peter Schlomka (with medal, MorphoDetection), Ewald Roessl (Philips), and Gerhard Martens (Philips). Title: Experimental feasibility of multi-energy photon-counting K-edge imaging in pre-clinical computed tomography Authors: Jens Peter Schlomka1, Ewald Roessl1, Ralf Dorscheid2, Stefan Dill2, Gerhard Martens1, Thomas Istel1, Christian Bäumer3, Christoph Herrmann3, Roger Steadman3, Günter Zeitler3, Amir Livne4 and Roland Proksa1 Institutions: 1 Philips Research Europe, Sector Medical Imaging Systems, Hamburg, Germany 2 Philips Research Europe, Engineering & Technology, Aachen, Germany 3 Philips Research Europe, Sector Medical Imaging Systems, Aachen, Germany 4 Philips Healthcare, Global Research and Advanced Development, Haifa, Israel Reference: Schlomka et al 2008 Phys. Med. Biol. 53 4031-47 This paper becomes the first to win both this citations prize and also the PMB best paper prize (The Roberts Prize), which it won for the year 2008. Discussion of the significance of the winning paper can be found in this medicalphysicsweb article from the time of the Roberts Prize win (http://medicalphysicsweb.org/cws/article/research/39907). The author's enthusiasm for their prototype spectral CT system has certainly been reflected in the large number of citations the paper subsequently has

The Runaway Greenhouse Effect on Earth and other Planets

NASA Technical Reports Server (NTRS)

Rabbette, Maura; Pilewskie, Peter; McKay, Christopher; Young, Robert

2001-01-01

Water vapor is an efficient absorber of outgoing longwave infrared radiation on Earth and is the primary greenhouse gas. Since evaporation increases with increasing sea surface temperature, and the increase in water vapor further increases greenhouse warming, there is a positive feedback. The runaway greenhouse effect occurs if this feedback continues unchecked until all the water has left the surface and enters the atmosphere. For Mars and the Earth the runaway greenhouse was halted when water vapor became saturated with respect to ice or liquid water respectively. However, Venus is considered to be an example of a planet where the runaway greenhouse effect did occur, and it has been speculated that if the solar luminosity were to increase above a certain limit, it would also occur on the Earth. Satellite data acquired during the Earth Radiation Budget Experiment (ERBE) under clear sky conditions shows that as the sea surface temperature (SST) increases, the rate of outgoing infrared radiation at the top of the atmosphere also increases, as expected. Over the pacific warm pool where the SST exceeds 300 K the outgoing radiation emitted to space actually decreases with increasing SST, leading to a potentially unstable system. This behavior is a signature of the runaway greenhouse effect on Earth. However, the SST never exceeds 303K, thus the system has a natural cap which stops the runaway. According to Stefan-Boltzmann's law the amount of heat energy radiated by the Earth's surface is proportional to (T(sup 4)). However, if the planet has a substantial atmosphere, it can absorb all infrared radiation from the lower surface before the radiation penetrates into outer space. Thus, an instrument in space looking at the planet does not detect radiation from the surface. The radiation it sees comes from some level higher up. For the earth#s atmosphere the effective temperature (T(sub e)) has a value of 255 K corresponding to the middle troposphere, above most of the

The Project LITE Spectrum Explorer

NASA Astrophysics Data System (ADS)

Brecher, K.; Carr, P.; Garik, P.; Weeks, E.

2002-12-01

We are developing a powerful new software tool which can help students at all levels understand the spectral properties of light. As a recent AAS survey of astronomy faculty members found (The Physics Teacher, 39, 52, 2001), essentially all introductory astronomy courses spend a significant amount of time dealing with the nature of light. Among the most difficult concepts for students to master are Kirchhoff's laws, blackbody radiation, the Stefan-Boltzmann law, Wien's law, the nature and causes of emission and absorption lines, and the relation of spectra to the underlying astronomical and physical processes producing them. Students often seem baffled by the connection between a spectrum seen visually as a color band and the same spectrum plotted graphically as intensity versus wavelength or frequency. The "Spectrum Explorer", a JAVA applet, is being developed as part of "Project LITE: Light Inquiry Through Experiments" to address these issues. It can be used by instructors in lecture presentations and by students learning at home or working in laboratory settings. We will show some of the current capabilities of the software which include simultaneous display of multiple spectra (normalized and non-normalized as a function of either wavelength or frequency) and the ability to manipulate blackbody spectra. Our future development plans include the addition of a variety of spectral data sets (from physics and chemistry as well as from astronomy); computed inputs from basic quantum mechanics (e.g. Zeeman effect in hydrogen) and from astronomical models (e.g. time varying spectra in binary stars); and the ability to test the effect of filters and physical processes (e.g. Rayleigh scattering) on input spectra. The Spectrum Explorer (along with many other applets about both the physical and perceptual nature of light) can be found on the Project LITE web site http://lite.bu.edu. Project LITE is supported by Grant #DUE-0125992 from the National Science Foundation

Pluto's Atmosphere from the July 2010 Stellar Occultation

NASA Astrophysics Data System (ADS)

Person, Michael J.; Elliot, J. L.; Bosh, A. S.; Gulbis, A. A. S.; Jensen-Clem, R.; Lockhart, M. F.; Zangari, A. M.; Zuluaga, C. A.; Levine, S. E.; Pasachoff, J. M.; Souza, S. P.; Lu, M.; Malamut, C.; Rojo, P.; Bailyn, C. D.; MacDonald, R. K. D.; Ivarsen, K. M.; Reichart, D. E.; LaCluyze, A. P.; Nysewander, M. C.; Haislip, J. B.

2010-10-01

We have observed the 4 July 2010 stellar occultation by Pluto as part of our program of monitoring Pluto's atmospheric changes over the last decade. Successful observations were obtained from three sites: Cerro Calan and Cerro Tololo, Chile, as well as the HESS-project site (High Energy Stereoscopic System) in southwestern Namibia. Successful telescope apertures ranged from 0.45 m to 1.0 m and resulted in seven occultation light curves for the event from among the three sites. Simultaneous analysis of the seven light curves indicates that Pluto's atmosphere continues to be stable, as the calculated atmospheric radii are consistent with those detected in 2006 (Elliot et al., AJ 134, 1, 2007) and 2007 (Person et al., AJ 136, 1510, 2008), continuing the stability that followed the large pressure increase detected between 1988 (Millis et al., Icarus 105, 282, 1993) and 2002 (Elliot et al., Nature 424, 165, 2003). We will present the overall astrometric solution as well as current profiles for Pluto's upper atmospheric temperature and pressure obtained from inversion of the light curves (Elliot, Person, and Qu, AJ 126, 1041, 2003). This work was supported, in part, by grants NNX10AB27G to MIT, NNX08AO50G to Williams College, and NNH08AI17I to the USNO from NASA's Planetary Astronomy Division. The 0.75-m ATOM (Automatic Telescope for Optical Monitoring) light curve was obtained with the generous assistance of the HESS-project staff, arranged by Stefan Wagner and Marcus Hauser of the University of Heidelberg. The 0.45-m Goto telescope at Cerro Calán National Astronomical Observatory, Universidad de Chile, was donated by the Government of Japan. PROMPT (Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes) observations at Cerro Tololo were made possible by the Robert Martin Ayers Science Fund. Student participation was supported in part by NSF's REU program and NASA's Massachusetts Space Grant.

Drying in porous media with gravity-stabilized fronts: experimental results.

PubMed

Yiotis, A G; Salin, D; Tajer, E S; Yortsos, Y C

2012-08-01

In a recent paper [Yiotis et al., Phys. Rev. E 85, 046308 (2012)] we developed a model for the drying of porous media in the presence of gravity. It incorporated effects of corner film flow, internal and external mass transfer, and the effect of gravity. Analytical results were derived when gravity opposes drying and hence leads to a stable percolation drying front. In this paper, we test the theory using laboratory experiments. A series of isothermal drying experiments in glass bead packings saturated with volatile hydrocarbons is conducted. The transparent glass cells containing the packing allow for the visual monitoring of the phase distribution patterns below the surface, including the formation of liquid films, as the gaseous phase invades the pore space, and for the control of the thickness of the diffusive mass boundary layer over the packing. The experimental results agree very well with theory, provided that the latter is generalized to account for the effects of corner roundness in the film region (which was neglected in the theoretical part). We demonstrate the existence of an early constant rate period (CRP), which lasts as long as the films saturate the surface of the packing, and of a subsequent falling rate period (FRP), which begins practically after the detachment of the film tips from the external surface. During the CRP, the process is controlled by diffusion within the stagnant gaseous phase in the upper part of the cells, yielding a Stefan tube problem solution. During the FRP, the process is controlled by diffusion within the packing, with a drying rate inversely proportional to the observed position of the film tips in the cell. Theoretical and experimental results compare favorably for a specific value of the roundness of the films, which is found to be constant and equal to 0.2 for various conditions, and verify the theoretical dependence on the capillary Ca(f), Bond Bo, and Sherwood Sh numbers.

Substitution Structures of Large Molecules and Medium Range Correlations in Quantum Chemistry Calculations

NASA Astrophysics Data System (ADS)

Evangelisti, Luca; Pate, Brooks

2017-06-01

A study of the minimally exciting topic of agreement between experimental and measured rotational constants of molecules was performed on a set of large molecules with 16-18 heavy atoms (carbon and oxygen). The molecules are: nootkatone (C_{15}H_{22}O), cedrol (C_{15}H_{26}O), ambroxide (C_{16}H_{28}O), sclareolide (C_{16}H_{22}O_{2}), and dihydroartemisinic acid (C_{15}H_{24}O_{2}). For this set of molecules we obtained 13C-subsitution structures for six molecules (this includes two conformers of nootkatone). A comparison of theoretical structures and experimental substitution structures was performed in the spirit of the recent work of Grimme and Steinmetz.[1] Our analysis focused the center-of-mass distance of the carbon atoms in the molecules. Four different computational methods were studied: standard DFT (B3LYP), dispersion corrected DFT (B3LYP-D3BJ), hybrid DFT with dispersion correction (B2PLYP-D3), and MP2. A significant difference in these theories is how they handle medium range correlation of electrons that produce dispersion forces. For larger molecules, these dispersion forces produce an overall contraction of the molecule around the center-of-mass. DFT poorly treats this effect and produces structures that are too expanded. MP2 calculations overestimate the correction and produce structures that are too compact. Both dispersion corrected DFT methods produce structures in excellent agreement with experiment. The analysis shows that the difference in computational methods can be described by a linear error in the center-of-mass distance. This makes it possible to correct poorer performing calculations with a single scale factor. We also reexamine the issue of the "Costain error" in substitution structures and show that it is significantly larger in these systems than in the smaller molecules used by Costain to establish the error limits. [1] Stefan Grimme and Marc Steinmetz, "Effects of London dispersion correction in density functional theory on

Mercury speciation on three European mining districts by XANES techniques

NASA Astrophysics Data System (ADS)

Esbri, J. M.; Garcia-Noguero, E. M.; Guerrero, B.; Kocman, D.; Bernaus, A.; Gaona, X.; Higueras, P.; Alvarez, R.; Loredo, J.; Horvat, M.; Ávila, M.

2009-04-01

The mobility, bioavailability and toxicity of mercury in the environment depend on the chemical species in which is present in soil, sediments, water or air. In this work we used synchrotron radiation to determine mercury species in geological samples of three mercury mining districts: Almadén (Spain), Idria (Slovenia) and Asturias (Spain). The aim of this study was to find differences on mobility and bioavailability of mercury on three mining districts with different type of mineralization. For this porpoises we selected samples of ore, calcines, soils and stream sediments from the three sites, completely characterized by the Almadén School of Mines, Josef Stefan Institute of Ljubljana and Oviedo School of Mines. Speciation of mercury was carried out on Synchrotron Laboratories of Hamburg (HASYLAB) by XANES techniques. Spectra of pure compounds [HgCl2, HgSO4, HgO, CH3HgCl, Hg2Cl2 (calomel), HgSred (cinnabar), HgSblack (metacinnabar), Hg2NCl0.5(SO4)0.3(MoO4)0.1(CO3)0.1(H2O) (mosesite), Hg3S2Cl2 (corderoite), Hg3(SO4)O2 (schuetteite) y Hg2ClO (terlinguaite)] were obtained on transmittance mode. The number and type of the compounds required to reconstruct experimental spectra for each sample was obtained by PCA analysis and linear fitting of minimum quadratics of the pure compounds spectra. This offers a semiquantitative approach to the mineralogical constitution of each analyzed sample. The results put forward differences on the efficiency of roasting furnaces from the three studied sites, evidenced by the presence of metacinnabar on the less efficient (Almadén and Asturias) and absence on the most efficient (Idria). For the three studied sites, sulfide species (cinnabar and metacinnabar) were largely more abundant than soluble species (chlorides and sulfates). On the other hand, recent results on the mobility of both Hg and As on the target sites will be presented. These results correlate with the related chemical species found by XANES techniques.

Project LITE Spectroscopy

NASA Astrophysics Data System (ADS)

Weeks, E.; Brecher, K.; Carr, P.; Garik, P.

2003-12-01

Spectroscopy is one of the most important tools used by astronomers to disentangle information about the universe. However, it is one of the most challenging subjects in undergraduate astronomy courses. Among the most difficult concepts for students to master are Kirchhoff's laws, blackbody radiation, the Stefan-Boltzmann law, Wien's law, the nature and causes of emission and absorption lines, and the relation of spectra to the underlying astronomical and physical processes producing them. Students often seem baffled by the connection between a spectrum seen visually as a color band and the same spectrum plotted graphically as intensity versus wavelength or frequency. Project LITE (Light Inquiry Through Experiments) is a software, curriculum, and materials development project at Boston University. As part of the project, we are currently developing a suite of spectroscopic tools for astronomy education. We are also assessing their effectiveness in improving conceptual understanding of spectroscopic phenomena by astronomy students at the undergraduate level. The spectroscopy component of Project LITE includes take-home laboratory materials and experiments, which are integrated with web-based software. We have also developed a novel quantitative handheld binocular spectrometer (patent pending). Here we present an overview of the Project LITE homelab kits and curriculum, the Spectrum Explorer, and the Project LITE spectrometer. The homelab experiments and the Spectrum Explorer have been tested with students in a non-science majors introductory astronomy course as well as in a School of Education course for prospective elementary school science teachers. We present preliminary results of pre- and post-instruction surveys of student understanding of various spectral properties of light both from students who used the homelab activities and the Spectrum Explorer and those who did not. The Spectrum Explorer (along with many other applets about both the physical and

Understanding, creating, and managing complex techno-socio-economic systems: Challenges and perspectives

NASA Astrophysics Data System (ADS)

Helbing, D.; Balietti, S.; Bishop, S.; Lukowicz, P.

2011-05-01

This contribution reflects on the comments of Peter Allen [1], Bikas K. Chakrabarti [2], Péter Érdi [3], Juval Portugali [4], Sorin Solomon [5], and Stefan Thurner [6] on three White Papers (WP) of the EU Support Action Visioneer (www.visioneer.ethz.ch). These White Papers are entitled "From Social Data Mining to Forecasting Socio-Economic Crises" (WP 1) [7], "From Social Simulation to Integrative System Design" (WP 2) [8], and "How to Create an Innovation Accelerator" (WP 3) [9]. In our reflections, the need and feasibility of a "Knowledge Accelerator" is further substantiated by fundamental considerations and recent events around the globe. newpara The Visioneer White Papers propose research to be carried out that will improve our understanding of complex techno-socio-economic systems and their interaction with the environment. Thereby, they aim to stimulate multi-disciplinary collaborations between ICT, the social sciences, and complexity science. Moreover, they suggest combining the potential of massive real-time data, theoretical models, large-scale computer simulations and participatory online platforms. By doing so, it would become possible to explore various futures and to expand the limits of human imagination when it comes to the assessment of the often counter-intuitive behavior of these complex techno-socio-economic-environmental systems. In this contribution, we also highlight the importance of a pluralistic modeling approach and, in particular, the need for a fruitful interaction between quantitative and qualitative research approaches. newpara In an appendix we briefly summarize the concept of the FuturICT flagship project, which will build on and go beyond the proposals made by the Visioneer White Papers. EU flagships are ambitious multi-disciplinary high-risk projects with a duration of at least 10 years amounting to an envisaged overall budget of 1 billion EUR [10]. The goal of the FuturICT flagship initiative is to understand and manage complex

Pharmacy Customers' Experiences With Electronic Prescriptions: Cross-Sectional Survey on Nationwide Implementation in Finland.

PubMed

Lämsä, Elina; Timonen, Johanna; Ahonen, Riitta

2018-02-23

/418, 6.0%) at the pharmacy. The most common way of keeping up to date with ePrescriptions was to ask at the pharmacy (631/1278, 49.37%). The vast majority of the respondents were satisfied with ePrescriptions as a whole (1221/1274, 95.84%). Finnish pharmacy customers are satisfied with the recently implemented nationwide ePrescription system. They seldom have any difficulties purchasing medicines, renewing their ePrescriptions, or acting on behalf of someone else at the pharmacy. Customers usually keep up to date with their ePrescriptions by asking at the pharmacy. However, some customers are unaware of the practices or have difficulty keeping up to date with the status of their ePrescriptions. The provision of relevant information and assistance by health care professionals is therefore required to promote customers' adoption of the ePrescription system. ©Elina Lämsä, Johanna Timonen, Riitta Ahonen. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 23.02.2018.

Luck Reveals Stellar Explosion's First Moments

NASA Astrophysics Data System (ADS)

2008-05-01

Through a stroke of luck, astronomers have witnessed the first violent moments of a stellar explosion known as a supernova. Astronomers have seen thousands of these stellar explosions, but all previous supernovae were discovered days after the event had begun. This is the first time scientists have been able to study a supernova from its very beginning. Seeing one just moments after the event began is a major breakthrough that points the way to unraveling longstanding mysteries about how such explosions really work. Galaxy Before Supernova Explosion NASA's Swift satellite took these images of SN 2007uy in galaxy NGC 2770 before SN 2008D exploded. An X-ray image is on the left; image at right is in visible light. CREDIT: NASA/Swift Science Team/Stefan Immler. Large Image With Labels Large Image Without Labels Galaxy After Supernova Explosion On January 9, 2008, Swift caught a bright X-ray burst from an exploding star. A few days later, SN 2008D appeared in visible light. CREDIT: NASA/Swift Science Team/Stefan Immler. Large Image With Labels Large Image Without Labels "For years, we have dreamed of seeing a star just as it was exploding," said team leader Alicia Soderberg, a Hubble and Carnegie-Princeton Fellow at Princeton University. "This newly-born supernova is going to be the Rosetta Stone of supernova studies for years to come." Theorists had predicted for four decades that a bright burst of X-rays should be produced as the shock wave from a supernova blasts out of the star and through dense material surrounding the star. However, in order to see this burst, scientists faced the nearly-impossible challenge of knowing in advance where to point their telescopes to catch a supernova in the act of exploding. On January 9, luck intervened. Soderberg and her colleagues were making a scheduled observation of the galaxy NGC 2770, 88 million light-years from Earth, using the X-ray telescope on NASA's Swift satellite. During that observation, a bright burst of X

Editorial: Focus on Dynamics and Thermalization in Isolated Quantum Many-Body Systems

NASA Astrophysics Data System (ADS)

Cazalilla, M. A.; Rigol, M.

2010-05-01

interaction quenches in the Hubbard model: prethermalization and non-equilibrium dynamics Michael Moeckel and Stefan Kehrein Quantum quenches in integrable field theories Davide Fioretto and Giuseppe Mussardo Dynamical delocalization of Majorana edge states by sweeping across a quantum critical point A Bermudez, L Amico and M A Martin-Delgado Thermometry with spin-dependent lattices D McKay and B DeMarco Near-adiabatic parameter changes in correlated systems: influence of the ramp protocol on the excitation energy Martin Eckstein and Marcus Kollar Sudden change of the thermal contact between two quantum systems J Restrepo and S Camalet Reflection of a Lieb-Liniger wave packet from the hard-wall potential D Jukić and H Buljan Probing interaction-induced ferromagnetism in optical superlattices J von Stecher, E Demler, M D Lukin and A M Rey Sudden interaction quench in the quantum sine-Gordon model Javier Sabio and Stefan Kehrein Dynamics of an inhomogeneous quantum phase transition Jacek Dziarmaga and Marek M Rams

Hail statistic in Western Europe based on a hyrid cell-tracking algorithm combining radar signals with hailstone observations

NASA Astrophysics Data System (ADS)

Fluck, Elody

2015-04-01

Hail statistic in Western Europe based on a hybrid cell-tracking algorithm combining radar signals with hailstone observations Elody Fluck¹, Michael Kunz¹ , Peter Geissbühler², Stefan P. Ritz² With hail damage estimated over Billions of Euros for a single event (e.g., hailstorm Andreas on 27/28 July 2013), hail constitute one of the major atmospheric risks in various parts of Europe. The project HAMLET (Hail Model for Europe) in cooperation with the insurance company Tokio Millennium Re aims at estimating hail probability, hail hazard and, combined with vulnerability, hail risk for several European countries (Germany, Switzerland, France, Netherlands, Austria, Belgium and Luxembourg). Hail signals are obtained from radar reflectivity since this proxy is available with a high temporal and spatial resolution using several hail proxies, especially radar data. The focus in the first step is on Germany and France for the periods 2005- 2013 and 1999 - 2013, respectively. In the next step, the methods will be transferred and extended to other regions. A cell-tracking algorithm TRACE2D was adjusted and applied to two dimensional radar reflectivity data from different radars operated by European weather services such as German weather service (DWD) and French weather service (Météo-France). Strong convective cells are detected by considering 3 connected pixels over 45 dBZ (Reflectivity Cores RCs) in a radar scan. Afterwards, the algorithm tries to find the same RCs in the next 5 minute radar scan and, thus, track the RCs centers over time and space. Additional information about hailstone diameters provided by ESWD (European Severe Weather Database) is used to determine hail intensity of the detected hail swaths. Maximum hailstone diameters are interpolated along and close to the individual hail tracks giving an estimation of mean diameters for the detected hail swaths. Furthermore, a stochastic event set is created by randomizing the parameters obtained from the

Multi-step Monte Carlo calculations applied to nuclear reactor instrumentation - source definition and renormalization to physical values

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

Radulovic, Vladimir; Barbot, Loic; Fourmentel, Damien

, which were recently irradiated in the Jozef Stefan Institute TRIGA Mark II reactor in Ljubljana, Slovenia, and provides recommendations on how they can be overcome. The paper concludes with a discussion on the renormalization of the results from the second step calculations, to obtain accurate physical values. (authors)« less

Astrometry With the Hubble Space Telescope: Trigonometric Parallaxes of Planetary Nebula Nuclei NGC 6853, NGC 7293, ABELL 31, and DeHt 5

NASA Technical Reports Server (NTRS)

Benedict, G. F.; McArthur, Barbara E.; Napiwotzki, Ralf; Harrison, Thomas E.; Harris, Hugh C.; Nelan, Edmund; Bond, Howard E; Patterson, Richard J.; Ciardullo, Robin

2009-01-01

We present absolute parallaxes and relative proper motions for the central stars of the planetary nebulae NGC 6853 (The Dumbbell), NGC 7293 (The Helix), Abell 31, and DeHt 5. This paper details our reduction and analysis using DeHt 5 as an example. We obtain these planetary nebula nuclei (PNNi) parallaxes with astrometric data from Fine Guidance Sensors FGS 1r and FGS 3, white-light interferometers on the Hubble Space Telescope. Proper motions, spectral classifications and VJHKT2M and DDO51 photometry of the stars comprising the astrometric reference frames provide spectrophotometric estimates of reference star absolute parallaxes. Introducing these into our model as observations with error, we determine absolute parallaxes for each PNN. Weighted averaging with previous independent parallax measurements yields an average parallax precision, sigma (sub pi)/ pi = 5%. Derived distances are: d(sub NGC6853) = 405(exp +28 sub -25) pc, d(sub NGC7293) = 216(exp +14 sub -12) pc, d(sub Abell31) = 621(exp +91 sub -70) pc, and d(sub DeHt5) = 345(exp +19 sub -17) pc. These PNNi distances are all smaller than previously derived from spectroscopic analyses of the central stars. To obtain absolute magnitudes from these distances requires estimates of interstellar extinction. We average extinction measurements culled from the literature, from reddening based on PNNi intrinsic colors derived from model SEDs, and an assumption that each PNN experiences the same rate of extinction as a function of distance as do the reference stars nearest (in angular separation) to each central star. We also apply Lutz-Kelker bias corrections. The absolute magnitudes and effective temperatures permit estimates of PNNi radii through both the Stefan-Boltzmann relation and Eddington fluxes. Comparing absolute magnitudes with post-AGB models provides mass estimates. Masses cluster around 0.57 solar Mass, close to the peak of the white dwarf mass distribution. Adding a few more PNNi with well

Experiences in utilization of research reactors in Yugoslavia

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

Copic, M.; Gabrovsek, Z.; Pop-Jordanov, J.

1971-06-15

The nuclear institutes in Yugoslavia possess three research reactors. Since 1958, two heavy-water reactors have been in operation at the 'Boris Kidric' Institute, a zero-power reactor RB and a 6. 5-MW reactor RA. At the Jozef Stefan Institute, a 250-kW TRIGA Mark II reactor has been operating since 1966. All reactors are equipped with the necessary experimental facilities. The main activities based on these reactors are: (1) fundamental research in solid-state and nuclear physics; (2) R and D activities related to nuclear power program; and (3) radioisotope production. In fundamental physics, inelastic neutron scattering and diffraction phenomena are studied bymore » means of the neutron beam tubes and applied to investigations of the structures of solids and liquids. Valuable results are also obtained in n - γ reaction studies. Experiments connected with the fuel -element development program, owing to the characteristics of the existing reactors, are limited to determination of the fuel element parameters, to studies on the purity of uranium, and to a small number of capsule irradiations. All three reactors are also used for the verification of different methods applied in the analysis of power reactors, particularly concerning neutron flux distributions, the optimization of reactor core configurations and the shielding effects. An appreciable irradiation space in the reactors is reserved for isotope production. Fruitful international co-operation has been established in all these activities, on the basis of either bilateral or multilateral arrangements. The paper gives a critical analysis of the utilization of research reactors in a developing country such as Yugoslavia. The investments in and the operational costs of research reactors are compared with the benefits obtained in different areas of reactor application. The impact on the general scientific, technological and educational level in the country is also considered. In particular, an attempt is made ro

Extreme QCD 2012 (xQCD)

NASA Astrophysics Data System (ADS)

2013-04-01

Acknowledgements This conference would not have been possible without the generous support from Brookhaven National Laboratory and the George Washington University INS and IMPACT institutes, Columbian College of Arts and Sciences, the Office of Vice-President for Research, and the Department of Physics. We thank them wholeheartedly. We are also very grateful for the support of our colleagues on the local organizing committee, Walter Freeman and Frank Lee, and on the International Advisory Committee: Simon Hands, Tetsuo Hatsuda, Frithjof Karsch, Maria Paola Lombardo, Tereza Mendes, Atsushi Nakamura, Owe Philipsen, Claudia Ratti, Paul Romatschke, Misha Stephanov, and Nu Xu. List of participants Alexandru, Andrei George Washington University Bazavov, Alexei Brookhaven National Laboratory Bloch, Jacques University of Regensburg Braun-Munzinger, Peter EMMI, GSI Breto Rangel, Guillermo CMS/UC Davis D'Elia, Massimo University of Pisa, INFN Dexheimer, Veronica UFSC - Federal University of Santa Catarina Ding, Heng-Tong Brookhaven National Laboratory Dion, Alan Stony Brook University Dumitru, Adrian RBRC and Baruch College, CUNY Freeman, Walter George Washington University Gavai, Rajiv Tata Institute (TIFR), Mumbai Hanada, Masanori KEK Theory Center Hands, Simon Swansea University Hegde, Prasad Brookhaven National Laboratory Heinke, Craig University of Alberta Horvath, Ivan University of Kentucky Karsch, Frithjof Brookhaven National Laboratory Krieg, Stefan Wuppertal University Lattimer, James Stony Brook University Lee, Frank George Washington University Li, Anyi Institute for Nuclear Theory Liu, Keh-Fei University of Kentucky Lombardo, Maria Paola INFN - LNF Lottini, Stefano Goethe University, Frankfurt am Main Maezawa, Yu Brookhaven National Laboratory Miura, Kohtaroh Laboratori Nazionali di Frascati - INFN Monnai, Akihiko The University of Tokyo Mukherjee, Swagato Brookhaven National Laboratory Myers, Joyce University of Groningen Nakamura, Atsushi RIISE, Hiroshima

Modeling the Effect of Grain Size Mixing on Thermal Inertia Values Derived from Diurnal and Seasonal THEMIS Measurements

NASA Astrophysics Data System (ADS)

McCarty, C.; Moersch, J.

2017-12-01

Sedimentary processes have slowed over Mars' geologic history. Analysis of the surface today can provide insight into the processes that may have affected it over its history. Sub-resolved checkerboard mixtures of materials with different thermal inertias (and therefore different grain sizes) can lead to differences in thermal inertia values inferred from night and day radiance observations. Information about the grain size distribution of a surface can help determine the degree of sorting it has experienced or it's geologic maturity. Standard methods for deriving thermal inertia from measurements made with THEMIS can give values for the same location that vary by as much as 20% between scenes. Such methods make the assumption that each THEMIS pixel contains material that has uniform thermophysical properties. Here we propose that if a mixture of small and large particles is present within a pixel, the inferred thermal inertia will be strongly dominated by whichever particle is warmer at the time of the measurement because the power radiated by a surface is proportional (by the Stefan-Boltzmann law) to the fourth power of its temperature. This effect will result in a change in thermal inertia values inferred from measurements taken at different times of day and night. Therefore, we expect to see correlation between the magnitude of diurnal variations in inferred thermal inertia values and the degree of grain size mixing for a given pixel location. Preliminary work has shown that the magnitude of such diurnal variation in inferred thermal inertias is sufficient to detect geologically useful differences in grain size distributions. We hypothesize that at least some of the 20% variability in thermal inertias inferred from multiple scenes for a given location could be attributed to sub-pixel grain size mixing rather than uncertainty inherent to the experiment, as previously thought. Mapping the difference in inferred thermal inertias from day and night THEMIS

"Incidental fear cues increase monetary loss aversion": Correction to Schulreich, Gerhardt, and Heekeren (2016).

PubMed

2016-12-01

Reports an error in "Incidental fear cues increase monetary loss aversion" by Stefan Schulreich, Holger Gerhardt and Hauke R. Heekeren ( Emotion , 2016[Apr], Vol 16[3], 402-412). In the current article, there was an error in the Study 2 portion of the article. The fourth paragraph of the Results section should read as follows: Performing the same analyses as in Study 1, we found an effect of incidental fear cues on decision behavior. Participants accepted fewer gambles in the fearful-face condition (32.77%) than in the neutral-face condition (33.96%), with Z = -2.187, p = .027, d = -0.998 in the Wilcoxon signed-ranks test and β = 0.012, SE = 0.0053, F(1, 21) = 4.434, p = .047, partial η² = .174 in the linear regression. This suggests increased risk aversion in the fearful-face condition. Concerning personality, however, there were no significant between-subjects effects or between-within interaction effects (all ps = .349). (The following abstract of the original article appeared in record 2015-52358-001.) In many everyday decisions, people exhibit loss aversion-a greater sensitivity to losses relative to gains of equal size. Loss aversion is thought to be (at least partly) mediated by emotional-in particular, fear-related-processes. Decision research has shown that even incidental emotions, which are unrelated to the decision at hand, can influence decision making. The effect of incidental fear on loss aversion, however, is thus far unclear. In two studies, we experimentally investigated how incidental fear cues, presented during (Study 1) or before (Study 2) choices to accept or reject mixed gambles over real monetary stakes, influence monetary loss aversion. We find that the presentation of fearful faces, relative to the presentation of neutral faces, increased risk aversion-an effect that could be attributed to increased loss aversion. The size of this effect was moderated by psychopathic personality: Fearless dominance, in particular its interpersonal facet

Tracing the 5000-year recorded history of inorganic thin films from ˜3000 BC to the early 1900s AD

NASA Astrophysics Data System (ADS)

Greene, J. E.

2014-12-01

Gold is very likely the first metal discovered by man, more than 11 000 years ago. However, unlike copper (˜9000 BC), bronze (˜3500 BC), and wrought iron (˜2500-3000 BC), gold is too soft for fabrication of tools and weapons. Instead, it was used for decoration, religious artifacts, and commerce. The earliest documented inorganic thin films were gold layers, some less than 3000 Å thick, produced chemi-mechanically by Egyptians approximately 5000 years ago. Examples, gilded on statues and artifacts (requiring interfacial adhesion layers), were found in early stone pyramids dating to ˜2650 BC in Saqqara, Egypt. Spectacular samples of embossed Au sheets date to at least 2600 BC. The Moche Indians of northern Peru developed electroless gold plating (an auto-catalytic reaction) in ˜100 BC and applied it to intricate Cu masks. The earliest published electroplating experiments were ˜1800 AD, immediately following the invention of the dc electrochemical battery by Volta. Chemical vapor deposition (CVD) of metal films was reported in 1649, atmospheric arc deposition of oxides (Priestley) in the mid-1760s, and atmospheric plasmas (Siemens) in 1857. Sols were produced in the mid-1850s (Faraday) and sol-gel films synthesized in 1885. Vapor phase film growth including sputter deposition (Grove, 1852), vacuum arc deposition ("deflagration," Faraday, 1857), plasma-enhanced CVD (Barthelot, 1869) and evaporation (Stefan, Hertz, and Knudsen, 1873-1915) all had to wait for the invention of vacuum pumps whose history ranges from ˜1650 for mechanical pumps, through ˜1865 for mercury pumps that produce ballistic pressures in small systems. The development of crystallography, beginning with Plato in 360 BC, Kepler in 1611, and leading to Miller indices (1839) for describing orientation and epitaxial relationships in modern thin film technology, was already well advanced by the 1780s (Haüy). The starting point for the development of heterogeneous thin film nucleation theory was

Multicomponent transport in membranes for redox flow batteries

NASA Astrophysics Data System (ADS)

Monroe, Charles

2015-03-01

Redox flow batteries (RFBs) incorporate separator membranes, which ideally prevent mixing of electrochemically active species while permitting crossover of inactive supporting ions. Understanding crossover and membrane selectivity may require multicomponent transport models that account for solute/solute interactions within the membrane, as well as solute/membrane interactions. Application of the Onsager-Stefan-Maxwell formalism allows one to account for all the dissipative phenomena that may accompany component fluxes through RFB membranes. The magnitudes of dissipative interactions (diffusional drag forces) are quantified by matching experimentally established concentration transients with theory. Such transients can be measured non-invasively using DC conductometry, but the accuracy of this method requires precise characterization of the bulk RFB electrolytes. Aqueous solutions containing both vanadyl sulfate (VOSO4) and sulfuric acid (H2SO4) are relevant to RFB technology. One of the first precise characterizations of aqueous vanadyl sulfate has been implemented and will be reported. To assess the viability of a separator for vanadium RFB applications with cell-level simulations, it is critical to understand the tendencies of various classes of membranes to absorb (uptake) active species, and to know the relative rates of active-species and supporting-electrolyte diffusion. It is also of practical interest to investigate the simultaneous diffusion of active species and supports, because interactions between solutes may ultimately affect the charge efficiency and power efficiency of the RFB system as a whole. A novel implementation of Barnes's classical model of dialysis-cell diffusion [Physics 5:1 (1934) 4-8] is developed to measure the binary diffusion coefficients and sorption equilibria for single solutes (VOSO4 or H2SO4) in porous membranes and cation-exchange membranes. With the binary diffusion and uptake measurement in hand, a computer simulation that

[Miraculous recoveries in the frescoes of the Decani Monastery].

PubMed

Jović, N; Jancić-Stefanović, J

1999-01-01

Serbian medieval medicine can be said to have the same characteristics as western medicine of those times in terms of practical medical science, whereas the ancillary medical branches were under Byzantine influence. Besides the compositions of Christ's miracles and paraboles are underlying part of the fresco/painting, the scenes of Christ's miraculous recoveries have an important place in the christian iconography of the New Testament events. One of the most impressive cycles of Christ's miracles in the Serbian and Byzantine medieval art was painted in c. 1340 year in the church dedicated to the Ascension of Lord Christ at Dechani Monastery and constructed between 1327 and 1335. A considerable number of 22 frescoes of different artistic value and technique displays the miraculous recovery of patients afflicted by various chronic ailments: paralytics (razlabljeni), lepers, and handicapped (blind, lame and deaf). One scene presents the bleeding (krvotociva) women. Scenes of recovery from nervous and mental diseases are especially impressive. Patients with atrophic arm, these with hemiplegy, epilepsy, an somnambulist boy, lunatics and possessed are there painted. The magnificent compositions of the miraculous recovery of a patient with ascites (debela, vodena bolest) and these affected by disorders of mainly neuromuscular and locomotor systems are performed by talented masters. The King Stefan Urosh Dechanski Third (1322-1331) founded the hospital in the Dechani Monastery, as a purely medical institution for providing treatment. This hospital was organized and modelled on the hospital in the Pantocrator Monastery in Constantinople. His biographer Gregory Camblak described that this hospital took in patients suffering from epilepsy (svestenoga neduga radi stradalcem) and serious nervous disorders, lepers, cripples, paralytics and those with lung diseases. Regardless of differences in the artistic level, most of these frescoes are impressively natural and realistic

Final Project Report (Oct 2014-Dec 2017): Zeolite Membranes for Krypton/Xenon Separation from Spent Nuclear Fuel Reprocessing Off-Gas

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

Kwon, Yeon Hye; Nair, Sankar; Bhave, Ramesh

-type and tubular membranes. This important development will allow a very compact and low-cost Kr/Xe separation system. Finally, a detailed process calculation for techno-economic analysis was performed by integrating Maxwell-Stefan model into cross-flow membrane system, in order to estimate the required number of membrane stages and the total cost.« less

Delayed Gamma Measurements in Different Nuclear Research Reactors Bringing Out the Importance of the Delayed Contribution in Gamma Flux Calculations

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

Fourmentel, D.; Radulovic, V.; Barbot, L.

Neutron and gamma flux levels are key parameters in nuclear research reactors. In Material Testing Reactors, such as the future Jules Horowitz Reactor, under construction at the French Alternative Energies and Atomic Energy Commission (CEA Cadarache, France), the expected gamma flux levels are very high (nuclear heating is of the order of 20 W/g at 100 MWth). As gamma rays deposit their energy in the reactor structures and structural materials it is important to take them into account when designing irradiation devices. There are only a few sensors which allow measurements of the nuclear heating ; a recent development atmore » the CEA Cadarache allows measurements of the gamma flux using a miniature ionization chamber (MIC). The measured MIC response is often compared with calculation using modern Monte Carlo (MC) neutron and photon transport codes, such as TRIPOLI-4 and MCNP6. In these calculations only the production of prompt gamma rays in the reactor is usually modelled thus neglecting the delayed gamma rays. Hence calculations and measurements are usually in better accordance for the neutron flux than for the gamma flux. In this paper we study the contribution of delayed gamma rays to the total MIC signal in order to estimate the systematic error in gamma flux MC calculations. In order to experimentally determine the delayed gamma flux contributions to the MIC response, we performed gamma flux measurements with CEA developed MIC at three different research reactors: the OSIRIS reactor (MTR - 70 MWth at CEA Saclay, France), the TRIGA MARK II reactor (TRIGA - 250 kWth at the Jozef Stefan Institute, Slovenia) and the MARIA reactor (MTR - 30 MWth at the National Center for Nuclear Research, Poland). In order to experimentally assess the delayed gamma flux contribution to the total gamma flux, several reactor shut down (scram) experiments were performed specifically for the purpose of the measurements. Results show that on average about 30 % of the MIC signal is

Lessons Learned From a Living Lab on the Broad Adoption of eHealth in Primary Health Care.

PubMed

Swinkels, Ilse Catharina Sophia; Huygens, Martine Wilhelmina Johanna; Schoenmakers, Tim M; Oude Nijeweme-D'Hollosy, Wendy; van Velsen, Lex; Vermeulen, Joan; Schoone-Harmsen, Marian; Jansen, Yvonne Jfm; van Schayck, Onno Cp; Friele, Roland; de Witte, Luc

2018-03-29

-management purposes, and health care professionals stressed the potential benefits of eHealth and were interested in using eHealth to distinguish themselves from other care organizations. In addition, eHealth entrepreneurs valued the collaboration among SMEs as they were not big enough to enter the health care market on their own and valued the collaboration with research institutes. Furthermore, health care insurers and policy makers shared the ambition and need for the development and implementation of an integrated eHealth infrastructure. For optimal and sustainable use of eHealth, patients should be actively involved, primary health care professionals need to be reinforced in their management, entrepreneurs should work closely with health care professionals and patients, and the government needs to focus on new health care models stimulating innovations. Only when all these parties act together, starting in local communities with a small range of eHealth tools, the potential of eHealth will be enforced. ©Ilse Catharina Sophia Swinkels, Martine Wilhelmina Johanna Huygens, Tim M Schoenmakers, Wendy Oude Nijeweme-D'Hollosy, Lex van Velsen, Joan Vermeulen, Marian Schoone-Harmsen, Yvonne JFM Jansen, Onno CP van Schayck, Roland Friele, Luc de Witte. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 29.03.2018.

A Web-Based and Print-Based Computer-Tailored Physical Activity Intervention for Prostate and Colorectal Cancer Survivors: A Comparison of User Characteristics and Intervention Use.

PubMed

Golsteijn, Rianne Henrica Johanna; Bolman, Catherine; Peels, Denise Astrid; Volders, Esmee; de Vries, Hein; Lechner, Lilian

2017-08-23

between initial Web-based (4/170, 2.4%) and print-based (11/79, 14%) participants. Participants were less likely to start Web-based with higher age (odds ratio [OR]=0.93), longer time since last treatment (OR=0.87), and higher fatigue (OR=0.96), and more likely with higher education (OR=4.08) and having completed treatments (OR=5.58). Those who were older (OR=0.93) and post treatment for a longer time (OR=0.86) were less likely to use Web-based intervention materials. Initial print-based participants predominantly used print-based materials, whereas initial Web-based participants used both print- and Web-based materials. To our knowledge, this is one of the first studies that assessed participant characteristics related to delivery mode in an intervention in which participants had a free choice of delivery modes. Use of print-based materials among the initial Web-based participants was substantial, indicating the importance of print-based materials. According to our findings, it may be important to offer Web- and print-based materials alongside each other. Providing Web-based materials only may exclude older, less educated, more fatigued, or currently treated participants; these groups are especially more vulnerable and could benefit most from PA interventions. ©Rianne Henrica Johanna Golsteijn, Catherine Bolman, Denise Astrid Peels, Esmee Volders, Hein de Vries, Lilian Lechner. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 23.08.2017.

Monogenic and polygenic determinants of sarcoma risk: an international genetic study.

PubMed

Ballinger, Mandy L; Goode, David L; Ray-Coquard, Isabelle; James, Paul A; Mitchell, Gillian; Niedermayr, Eveline; Puri, Ajay; Schiffman, Joshua D; Dite, Gillian S; Cipponi, Arcadi; Maki, Robert G; Brohl, Andrew S; Myklebost, Ola; Stratford, Eva W; Lorenz, Susanne; Ahn, Sung-Min; Ahn, Jin-Hee; Kim, Jeong Eun; Shanley, Sue; Beshay, Victoria; Randall, Robert Lor; Judson, Ian; Seddon, Beatrice; Campbell, Ian G; Young, Mary-Anne; Sarin, Rajiv; Blay, Jean-Yves; O'Donoghue, Seán I; Thomas, David M

2016-09-01

variants (known, expected, or predicted) were associated with earlier age of cancer onset. In addition to TP53, ATM, ATR, and BRCA2, an unexpected excess of functionally pathogenic variants was seen in ERCC2. Probands were more likely than controls to have multiple pathogenic variants compared with the combined control cohort group and the LifePool control cohort (OR 2·22, 95% CI 1·57-3·14, p=1·2 × 10(-6)) and the cumulative burden of multiple variants correlated with earlier age at cancer diagnosis (Mantel-Cox log-rank test for trend, p=0·0032). 66 of 1162 probands carried notifiable variants following expert clinical review (those recognised to be clinically significant to health and about which patients should be advised), whereas 293 (25%) probands carried variants with potential therapeutic significance. About half of patients with sarcoma have putatively pathogenic monogenic and polygenic variation in known and novel cancer genes, with implications for risk management and treatment. Rainbows for Kate Foundation, Johanna Sewell Research Foundation, Australian National Health and Medical Research Council, Cancer Australia, Sarcoma UK, National Cancer Institute, Liddy Shriver Sarcoma Initiative. Copyright © 2016 Elsevier Ltd. All rights reserved.

Committees

NASA Astrophysics Data System (ADS)

2012-11-01

Leadership Team of the IAHR Committee for Hydraulic Machinery and Systems Eduard EGUSQUIZA, UPC Barcelona, Spain, Chair François AVELLAN, EPFL-LMH, Switzerland, Past Chair Richard K FISHER, Voith Hydro Inc., USA, Past Chair Fidel ARZOLA, Edelca, Venezuela Michel COUSTON, Alstom Hydro, France Niklas DAHLBÄCKCK, Vatenfall, Sweden Normand DESY, Andritz VA TECH Hydro Ltd., Canada Chisachi KATO, University of Tokyo, Japan Andrei LIPEJ, Turboinstitut, Slovenija Torbjørn NIELSEN, NTNU, Norway Romeo SUSAN-RESIGA, 'Politehnica' University Timisoara, Romania Stefan RIEDELBAUCH, Stuggart University, Germany Albert RUPRECHT, Stuttgart University, Germany Qing-Hua SHI, Dong Fang Electrical Machinery Co., China Geraldo TIAGO, Universidade Federal de Itajubá, Brazil International Advisory Committee Shouqi YUAN (principal) Jiangsu University China QingHua SHI (principal) Dong Fang Electrical Machinery Co. China Fidel ARZOLA EDELCA Venezuela Thomas ASCHENBRENNER Voith Hydro GmbH & Co. KG Germany Anton BERGANT Litostroj Power doo Slovenia B C BHAOYAL Research & Technology Centre India Hermod BREKKE NTNU Norway Stuart COULSON Voith Hydro Inc. USA Paul COOPER Fluid Machinery Research Inc USA V A DEMIANOV Power Machines OJSC Russia Bart van ESCH Technische Universiteit Eindhoven Netherland Arno GEHRER Andritz Hydro Graz Austria Akira GOTO Ebara Corporation Japan Adiel GUINZBURG The Boeing Company USA D-H HELLMANN KSB AG Germany Ashvin HOSANGADI Combustion Research and Flow Technology USA Byung-Sun HWANG Korea Institute of Material Science Korea Toshiaki KANEMOTO Kyushu Institute of Technology Japan Mann-Eung KIM Korean Register of Shipping Korea Jiri KOUTNIK Voith Hydro GmbH & Co. KG Germany Jinkook LEE Eaton Corporation USA Young-Ho LEE Korea Maritime University Korea Woo-Seop LIM Hyosung Goodsprings Inc Korea Jun MATSUI Yokohama National University Japan Kazuyoshi Mitsubishi H I Ltd, Japan MIYAGAWA Christophe NICOLET Power Vision Engineering Srl Switzerland Maryse PAGE Hydro

EDITORIAL: Dialog on Science and Policy to Address the Climate Crisis to conclude the International Association of Research Universities Climate Congress, Copenhagen, Denmark Dialog on Science and Policy to Address the Climate Crisis to conclude the International Association of Research Universities Climate Congress, Copenhagen, Denmark

NASA Astrophysics Data System (ADS)

Baer, Paul; Kammen, Daniel M.

2009-06-01

(http://climatecongress.ku.dk/). Conference Chair Professor Katherine Richardson began the panel by reading the 'key messages'. She then she asked the panelists—Professor Stefan Rahmstorf, Professor Will Steffen, Lord Nicholas Stern, and Professor Dan Kammen to respond. After that, she invited the Danish Prime Minister, Mr Anders Fogh Rasmussen, to respond to the messages. Next there was a dialogue between the panelists and the Prime Minister, with closing remarks from the Prime Minister.

GSC 4232.2850, a new eclipsing binary with elliptical orbit

NASA Astrophysics Data System (ADS)

Goranskij, V.; Shugarov, S.; Kroll, P.; Golovin, A.

2005-04-01

(Mossakovskaja, 1993; Milone et al, 2000; Torres and Stefanic, 2001). The eclipse depth variations should be verified with more precise observations taken during the longer time interval.

Diffusion Driven Combustion Waves in Porous Media

NASA Technical Reports Server (NTRS)

Aldushin, A. P.; Matkowsky, B. J.

2000-01-01

Filtration of gas containing oxidizer, to the reaction zone in a porous medium, due, e.g., to a buoyancy force or to an external pressure gradient, leads to the propagation of Filtration combustion (FC) waves. The exothermic reaction occurs between the fuel component of the solid matrix and the oxidizer. In this paper, we analyze the ability of a reaction wave to propagate in a porous medium without the aid of filtration. We find that one possible mechanism of propagation is that the wave is driven by diffusion of oxidizer from the environment. The solution of the combustion problem describing diffusion driven waves is similar to the solution of the Stefan problem describing the propagation of phase transition waves, in that the temperature on the interface between the burned and unburned regions is constant, the combustion wave is described by a similarity solution which is a function of the similarity variable x/square root of(t) and the wave velocity decays as 1/square root of(t). The difference between the two problems is that in the combustion problem the temperature is not prescribed, but rather, is determined as part of the solution. We will show that the length of samples in which such self-sustained combustion waves can occur, must exceed a critical value which strongly depends on the combustion temperature T(sub b). Smaller values of T(sub b) require longer sample lengths for diffusion driven combustion waves to exist. Because of their relatively small velocity, diffusion driven waves are considered to be relevant for the case of low heat losses, which occur for large diameter samples or in microgravity conditions, Another possible mechanism of porous medium combustion describes waves which propagate by consuming the oxidizer initially stored in the pores of the sample. This occurs for abnormally high pressure and gas density. In this case, uniformly propagating planar waves, which are kinetically controlled, can propagate, Diffusion of oxidizer decreases

PREFACE: Nanospintronics design and realization

NASA Astrophysics Data System (ADS)

Akai, Hisazumi; Katayama-Yoshida, Hiroshi; Kasai, Hideaki

2004-12-01

oral presentations and 44 contributed posters. The conference also has additional financial support from the Asahi Glass Foundation, the Foundation for Promotion of Material Science and Technology of Japan, the Izumi Science and Technology Foundation, the Kansai Research Foundation for Technology Promotion, the Kao Foundation for Arts and Sciences, the Murata Science Foundation, the Nanotechnology Researchers Network Center of Japan, and the Nippon Sheet Glass Foundation for Materials Science and Engineering. The 2nd International Conference on Nanospintronics Design and Realization will be held in Germany, in 2007, and will be organized by Stefan Blügel, Patrick Bruno, and Dieter Weiss. We hope to see you there.

Digital Gaming for Improving the Functioning of People With Traumatic Brain Injury: Randomized Clinical Feasibility Study.

PubMed

Välimäki, Maritta; Mishina, Kaisa; Kaakinen, Johanna K; Holm, Suvi K; Vahlo, Jukka; Kirjonen, Markus; Pekurinen, Virve; Tenovuo, Olli; Korkeila, Jyrki; Hämäläinen, Heikki; Sarajuuri, Jaana; Rantanen, Pekka; Orenius, Tage; Koponen, Aki

2018-03-19

. However, depression scores increased significantly between baseline and after 8 weeks and between baseline and after 3 months in the rehabilitative gaming group. No differences were found in patients' self-efficacy between the three measuring points in any of the groups. Participants did use the games (rehabilitation group: 93%, 27/29; entertainment group 100%, 29/29). Games were seen as a usable intervention (rehabilitation group: 70%, 14/29; entertainment group: 83%, 20/29). The rehabilitation group was less satisfied with the gaming intervention (68%, 13/29 vs 83%, 20/29), but they were more willing to use the game after the intervention period (76%, 16/29 vs 63%, 15/29). Total time spent on gaming during the intervention period was low (15.22 hour rehabilitation gaming group, 19.22 hour entertainment gaming group). We did not find differences between the groups in improvement in the outcome measures. The improvements in test performance by all three groups may reflect rehearsal effects. Entertainment gaming had elements that could be considered when rehabilitative games are designed for, implemented in, and assessed in larger clinical trials for persons with TBI. ClinicalTrials.gov NCT02425527; https://clinicaltrials.gov/ct2/show/NCT02425527 (Archived by WebCite at http://www.webcitation.org/6esKI1uDH). ©Maritta Välimäki, Kaisa Mishina, Johanna K Kaakinen, Suvi K Holm, Jukka Vahlo, Markus Kirjonen, Virve Pekurinen, Olli Tenovuo, Jyrki Korkeila, Heikki Hämäläinen, Jaana Sarajuuri, Pekka Rantanen, Tage Orenius, Aki Koponen. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 19.03.2018.

Which Extrinsic and Intrinsic Factors are Associated with Non-Contact Injuries in Adult Cricket Fast Bowlers?

PubMed

Olivier, Benita; Taljaard, Tracy; Burger, Elaine; Brukner, Peter; Orchard, John; Gray, Janine; Botha, Nadine; Stewart, Aimee; Mckinon, Warrick

2016-01-01

systematic review. The mean critical appraisal score of the papers included in this study was 6.88 (SD 1.15) out of a maximum of 9. The following factors were found to be associated with injury: bowling shoulder internal rotation strength deficit, compromised dynamic balance and lumbar proprioception (joint position sense), the appearance of lumbar posterior element bone stress, degeneration of the lumbar disc on magnetic resonance imaging (MRI), and previous injury. Conflicting results were found for the association of quadratus lumborum (QL) muscle asymmetry with injury. Technique-related factors associated with injury included shoulder-pelvis flexion-extension angle, shoulder counter-rotation, knee angle, and the proportion of side-flexion during bowling. Bowling workload was the only extrinsic factor associated with injury in adult cricket fast bowlers. A high bowling workload (particularly if it represented a sudden upgrade from a lower workload) increased the subsequent risk to sustaining an injury 1, 3 or 4 weeks later. Identifying the factors associated with injury is a crucial step which should precede the development of, and research into, the effectiveness of injury prevention programs. Once identified, risk factors may be included in pre-participation screening tools and injury prevention programs, and may also be incorporated in future research projects. Overall, the current review highlights the clear lack of research on factors associated with non-contact injury, specifically in adult cricket fast bowlers. Johanna Briggs Institute Database of Systematic Reviews and Implementation Reports 1387 (Olivier et al., JBI Database Syst Rev Implement Rep 13(1):3-13. doi: 10.11124/jbisrir-2015-1387 , 2015).

Instability of water-ice interface under turbulent flow

NASA Astrophysics Data System (ADS)

Izumi, Norihiro; Naito, Kensuke; Yokokawa, Miwa

2015-04-01

It is known that plane water-ice interface becomes unstable to evolve into a train of waves. The underside of ice formed on the water surface of rivers are often observed to be covered with ice ripples. Relatively steep channels which discharge melting water from glaciers are characterized by beds covered with a series of steps. Though the flowing agent inducing instability is not water but gas including water vapor, a similar train of steps have been recently observed on the Polar Ice Caps on Mars (Spiral Troughs). They are expected to be caused by the instability of water-ice interface induced by flowing fluid on ice. There have been some studies on this instability in terms of linear stability analysis. Recently, Caporeale and Ridolfi (2012) have proposed a complete linear stability analysis in the case of laminar flow, and found that plane water-ice interface is unstable in the range of sufficiently large Reynolds numbers, and that the important parameters are the Reynolds number, the slope angle, and the water surface temperature. However, the flow inducing instability on water-ice interface in the field should be in the turbulent regime. Extension of the analysis to the case of fully developed turbulent flow with larger Reynolds numbers is needed. We have performed a linear stability analysis on the instability of water-ice interface under turbulent flow conditions with the use of the Reynolds-averaged Navier-Stokes equations with the mixing length turbulent model, the continuity equation of flow, the diffusion/dispersion equation of heat, and the Stefan equation. In order to reproduce the accurate velocity distribution and the heat transfer in the vicinity of smooth walls with the use of the mixing length model, it is important to take into account of the rapid decrease in the mixing length in the viscous sublayer. We employ the Driest model (1956) to the formulation. In addition, as the thermal boundary condition at the water surface, we describe the

Different Effects of Roughness (Granularity) and Hydrophobicity

NASA Astrophysics Data System (ADS)

Shirtcliffe, Neil; McHale, Glen; Hamlett, Christopher; Newton, Michael

2010-05-01

With thanks to Stefan Doerr and Jorge Mataix-Solera for their invitation Superhydrophobicity is an interesting effect that appears to be simple on the outset; increased surface area from roughness increases interfacial area and therefore energy loss or gain. More extreme roughness prevents total wetting, resulting in gas pockets present at the surface and a drastic change in the properties of the system. Increases in complexity of the system, by adding porosity (granularity), allowing the structures to move, varying the shape of the roughness or the composition of the liquid used often has unexpected effects. Here we will consider a few of these related to complex topography. Overhanging features are commonly used in test samples as they perform better in some tests than simple roughness. It has been shown to be a prerequisite for superoleophobic surfaces as it allows liquids to be suspended for contact angles considerably below 90°. It also allows trapping of gas in lower layers even if the first layer is flooded. This is important in soils as a fixed bed of granules behaves just like a surface with overhanging roughness. Using simple geometry it is possible to predict at what contact angle penetration will occur. Plants have some structured superhydrophobic surfaces and we have shown that some use them in conjunction with other structured surfaces to control water flows. This allows some plants to survive in difficult environments and shows us how subtly different structures interact completely differently with water. Long fibres can either cause water droplets to roll over a plant surface or halt it in its tracks. Implications of this in soils include predicting when particles will adhere more strongly to water drops and why organic fibrous material may play a greater role in the behaviour of water in soils than may be expected from the amount present. The garden snail uses a biosurfactant that is very effective at wetting surfaces and can crawl over most

PREFACE: European Microbeam Analysis Society's 14th European Workshop on Modern Developments and Applications in Microbeam Analysis (EMAS 2015), Portorož, Slovenia, 3-7 May 2015

NASA Astrophysics Data System (ADS)

Llovet, Xavier; Matthews, Michael B.; Čeh, Miran; Langer, Enrico; Žagar, Kristina

2016-02-01

This volume of the IOP Conference Series: Materials Science and Engineering contains papers from the 14th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis which took place from the 3rd to the 7th of May 2015 in the Grand Hotel Bernardin, Portorož, Slovenia. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on a career in microbeam analysis can meet and discuss with the established experts. The workshops have a unique format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field.This workshop was organized in collaboration with the Jožef Stefan Institute and SDM - Slovene Society for Microscopy. The technical programme included the following topics: electron probe microanalysis, STEM and EELS, materials applications, cathodoluminescence and electron backscatter diffraction (EBSD), and their applications. As at previous workshops there was also a special oral session for young scientists. The best presentation by a young scientist was awarded with an invitation to attend the 2016 Microscopy and Microanalysis meeting at Columbus, Ohio. The prize went to Shirin Kaboli, of the Department of Metals and Materials Engineering of McGill University (Montréal, Canada), for her talk entitled "Electron channelling contrast reconstruction with electron backscattered diffraction". The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 71 posters from 16 countries were on display at the meeting and that the participants came from as far away as Japan, Canada, USA, and Australia. A selection of participants with posters was invited

R2R Eventlogger: Community-wide Recording of Oceanographic Cruise Science Events

NASA Astrophysics Data System (ADS)

Maffei, A. R.; Chandler, C. L.; Stolp, L.; Lerner, S.; Avery, J.; Thiel, T.

2012-12-01

Methods used by researchers to track science events during a science research cruise - and to note when and where these occur - varies widely. Handwritten notebooks, printed forms, watch-keeper logbooks, data-logging software, and customized software have all been employed. The quality of scientific results is affected by the consistency and care with which such events are recorded and integration of multi-cruise results is hampered because recording methods vary widely from cruise to cruise. The Rolling Deck to Repository (R2R) program has developed an Eventlogger system that will eventually be deployed on most vessels in the academic research fleet. It is based on the open software package called ELOG (http://midas.psi.ch/elog/) originally authored by Stefan Ritt and enhanced by our team. Lessons have been learned in its development and use on several research cruises. We have worked hard to find approaches that encourage cruise participants to use tools like the eventlogger. We examine these lessons and several eventlogger datasets from past cruises. We further describe how the R2R Science Eventlogger works in concert with the other R2R program elements to help coordinate research vessels into a coordinated mobile observing fleet. Making use of data collected on different research cruises is enabled by adopting common ways of describing science events, the science instruments employed, the data collected, etc. The use of controlled vocabularies and the practice of mapping these local vocabularies to accepted oceanographic community vocabularies helps to bind shipboard research events from different cruises into a more cohesive set of fleet-wide events that can be queried and examined in a cross-cruise manner. Examples of the use of the eventlogger during multi-cruise oceanographic research programs along with examples of resultant eventlogger data will be presented. Additionally we will highlight the importance of vocabulary use strategies to the success of the

Martin Stutzmann: Editor, Teacher, Scientist and Friend

NASA Astrophysics Data System (ADS)

Cardona, Manuel

2005-03-01

to launch in 2002 part (c) of the journal, devoted mainly, but not exclusively, to conference articles. Martin also introduced the publication of Feature Articles, topical issues, and the instrument of the Editor's Choice to highlight articles deemed to be especially interesting. He appointed Regional Editors (6 at this point) which represent the journal in important geographic regions. He also brought the journal online, a must these days. The upheavals that followed the collapse of most of the communist world, the rapid development of science in many emerging nations and the enhanced competitiveness, even in the developed countries, have not ebbed out. Some of them are particular damaging to the reputation of science in a world increasingly skeptical of its values. I am thinking of scientific misconduct and outright fraud, in the form of plagiarism and data fabrication. physica status solidi was also afflicted by this plague: after all, it happened in the best of families. Two of the most notorious offenders of the past decade, J. H. Schön and Y. Park, also visited physica status solidi. In two courageous editorials Martin Stutzmann and Stefan Hildebrandt (Managing Editor of the journal) rapidly exposed these cases of misconduct together with other cases in which there was also good reason to suspect misconduct. Some of the articles involved were rapidly retracted by the authors, others were not. It is reassuring to say that none of them had any impact worth mentioning (1-3 citations, mostly by the authors themselves or in the editorials just mentioned). Only few journal editors dared to convey to the readers a warning that some work of those authors may be faulty even if no air-tight proof was available. However, Martin and Stefan did. We wish that Martin will remain at the helm at least another decade, before he switches to research on the liquid state as practiced in Southern France.

Fungal Planet description sheets: 625-715.

PubMed

Crous, P W; Wingfield, M J; Burgess, T I; Carnegie, A J; Hardy, G E St J; Smith, D; Summerell, B A; Cano-Lira, J F; Guarro, J; Houbraken, J; Lombard, L; Martín, M P; Sandoval-Denis, M; Alexandrova, A V; Barnes, C W; Baseia, I G; Bezerra, J D P; Guarnaccia, V; May, T W; Hernández-Restrepo, M; Stchigel, A M; Miller, A N; Ordoñez, M E; Abreu, V P; Accioly, T; Agnello, C; Agustin Colmán, A; Albuquerque, C C; Alfredo, D S; Alvarado, P; Araújo-Magalhães, G R; Arauzo, S; Atkinson, T; Barili, A; Barreto, R W; Bezerra, J L; Cabral, T S; Camello Rodríguez, F; Cruz, R H S F; Daniëls, P P; da Silva, B D B; de Almeida, D A C; de Carvalho Júnior, A A; Decock, C A; Delgat, L; Denman, S; Dimitrov, R A; Edwards, J; Fedosova, A G; Ferreira, R J; Firmino, A L; Flores, J A; García, D; Gené, J; Giraldo, A; Góis, J S; Gomes, A A M; Gonçalves, C M; Gouliamova, D E; Groenewald, M; Guéorguiev, B V; Guevara-Suarez, M; Gusmão, L F P; Hosaka, K; Hubka, V; Huhndorf, S M; Jadan, M; Jurjević, Ž; Kraak, B; Kučera, V; Kumar, T K A; Kušan, I; Lacerda, S R; Lamlertthon, S; Lisboa, W S; Loizides, M; Luangsa-Ard, J J; Lysková, P; Mac Cormack, W P; Macedo, D M; Machado, A R; Malysheva, E F; Marinho, P; Matočec, N; Meijer, M; Mešić, A; Mongkolsamrit, S; Moreira, K A; Morozova, O V; Nair, K U; Nakamura, N; Noisripoom, W; Olariaga, I; Oliveira, R J V; Paiva, L M; Pawar, P; Pereira, O L; Peterson, S W; Prieto, M; Rodríguez-Andrade, E; Rojo De Blas, C; Roy, M; Santos, E S; Sharma, R; Silva, G A; Souza-Motta, C M; Takeuchi-Kaneko, Y; Tanaka, C; Thakur, A; Smith, M Th; Tkalčec, Z; Valenzuela-Lopez, N; van der Kleij, P; Verbeken, A; Viana, M G; Wang, X W; Groenewald, J Z

2017-12-01

raii from soil. Italy : Setophaeosphaeria citri on Citrus reticulata , Yuccamyces citri on Citrus limon. Japan : Glutinomyces brunneus (incl. Glutinomyces gen. nov.) from roots of Quercus sp. Netherlands (all from soil): Collariella hilkhuijsenii , Fusarium petersiae , Gamsia kooimaniorum , Paracremonium binnewijzendii , Phaeoisaria annesophieae , Plectosphaerella niemeijerarum , Striaticonidium deklijnearum , Talaromyces annesophieae , Umbelopsis wiegerinckiae , Vandijckella johannae (incl. Vandijckella gen. nov. and Vandijckellaceae fam. nov.), Verhulstia trisororum (incl. Verhulstia gen. nov.). New Zealand : Lasiosphaeria similisorbina on decorticated wood. Papua New Guinea : Pseudosubramaniomyces gen. nov. (based on Pseudosubramaniomyces fusisaprophyticus comb. nov.). Slovakia : Hemileucoglossum pusillum on soil. South Africa : Tygervalleyomyces podocarpi (incl. Tygervalleyomyces gen. nov.) on Podocarpus falcatus. Spain : Coniella heterospora from herbivorous dung, Hymenochaete macrochloae on Macrochloa tenacissima , Ramaria cistophila on shrubland of Cistus ladanifer. Thailand : Polycephalomyces phaothaiensis on Coleoptera larvae, buried in soil. Uruguay : Penicillium uruguayense from soil. Vietnam : Entoloma nigrovelutinum on forest soil, Volvariella morozovae on wood of unknown tree. Morphological and culture characteristics along with DNA barcodes are provided.

The Adverse Drug Reactions from Patient Reports in Social Media Project: Five Major Challenges to Overcome to Operationalize Analysis and Efficiently Support Pharmacovigilance Process.

PubMed

Bousquet, Cedric; Dahamna, Badisse; Guillemin-Lanne, Sylvie; Darmoni, Stefan J; Faviez, Carole; Huot, Charles; Katsahian, Sandrine; Leroux, Vincent; Pereira, Suzanne; Richard, Christophe; Schück, Stéphane; Souvignet, Julien; Lillo-Le Louët, Agnès; Texier, Nathalie

2017-09-21

, syntactic rules, and post-analysis processing, and (5) proposed a component-based architecture that allows storage of big data and accessibility to third-party applications through Web services. We demonstrated the feasibility of implementing a component-based architecture that allows collection of patient posts on the Internet, near real-time processing of those posts including annotation, and storage in big data structures. In the next steps, we will evaluate the posts identified by the system in social media to clarify the interest and relevance of such approach to improve conventional pharmacovigilance processes based on spontaneous reporting. ©Cedric Bousquet, Badisse Dahamna, Sylvie Guillemin-Lanne, Stefan J Darmoni, Carole Faviez, Charles Huot, Sandrine Katsahian, Vincent Leroux, Suzanne Pereira, Christophe Richard, Stéphane Schück, Julien Souvignet, Agnès Lillo-Le Louët, Nathalie Texier. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 21.09.2017.

A review on regional convection permitting climate modeling

NASA Astrophysics Data System (ADS)

van Lipzig, Nicole; Prein, Andreas; Brisson, Erwan; Van Weverberg, Kwinten; Demuzere, Matthias; Saeed, Sajjad; Stengel, Martin

2016-04-01

of using CPMs to study climate change it is necessary that these deficiencies are addressed in future research. Coordinated modeling programs are crucially needed to advance parameterizations of unresolved physics and to assess the full potential of CPMs. Brisson, E., K. Van Weverberg, M. Demuzere, A. Devis, S. Saeed, M. Stengel, N.P.M. van Lipzig, 2016. How well can a convection-permitting climate model reproduce 1 decadal statistics of precipitation, temperature and cloud characteristics? Clim. Dyn. (minor revisions). Prein, Andreas F., Wolfgang Langhans, Giorgia Fosser, Andrew Ferrone, Nikolina Ban, Klaus Goergen, Michael Keller, Merja Tölle, Oliver Gutjahr, Frauke Feser, Erwan Brisson, Stefan Kollet, Juerg Schmidli, Nicole P. M. van Lipzig, Ruby Leung. (2015) A review on regional convection-permitting climate modeling: Demonstrations, prospects, and challenges. Reviews of Geophysics 53:10.1002/rog.v53.2, 323-361

Flexible Description Language for HPC based Processing of Remote Sense Data

NASA Astrophysics Data System (ADS)

Nandra, Constantin; Gorgan, Dorian; Bacu, Victor

2016-04-01

information: [1] Gorgan, D., "Flexible and Adaptive Processing of Earth Observation Data over High Performance Computation Architectures", International Conference and Exhibition Satellite 2015, August 17-19, Houston, Texas, USA. [2] Bigearth project - flexible processing of big earth data over high performance computing architectures. http://cgis.utcluj.ro/bigearth, (2014) [3] Nandra, C., Gorgan, D., "Workflow Description Language for Defining Big Earth Data Processing Tasks", Proceedings of the Intelligent Computer Communication and Processing (ICCP), IEEE-Press, pp. 461-468, (2015). [4] Bacu, V., Stefan, T., Gorgan, D., "Adaptive Processing of Earth Observation Data on Cloud Infrastructures Based on Workflow Description", Proceedings of the Intelligent Computer Communication and Processing (ICCP), IEEE-Press, pp.444-454, (2015). [5] Mihon, D., Bacu, V., Colceriu, V., Gorgan, D., "Modeling of Earth Observation Use Cases through the KEOPS System", Proceedings of the Intelligent Computer Communication and Processing (ICCP), IEEE-Press, pp. 455-460, (2015).

Measured and parameterized energy fluxes estimated for Atlantic transects of RV Polarstern

NASA Astrophysics Data System (ADS)

Bumke, Karl; Macke, Andreas; Kalisch, John; Kleta, Henry

2013-04-01

Even to date energy fluxes over the oceans are difficult to assess. As an example the relative paucity of evaporation observations and the uncertainties of currently employed empirical approaches lead to large uncertainties of evaporation products over the ocean (e.g. Large and Yeager, 2009). Within the frame of OCEANET (Macke et al., 2010) we performed such measurements on Atlantic transects between Bremerhaven (Germany) and Cape Town (South Africa) or Punta Arenas (Chile) onboard RV Polarstern during the recent years. The basic measurements of sensible and latent heat fluxes are inertial-dissipation (e.g. Dupuis et al., 1997) flux estimates and measurements of the bulk variables. Turbulence measurements included a sonic anemometer and an infrared hygrometer, both mounted on the crow's nest. Mean meteorological sensors were those of the ship's operational measurement system. The global radiation and the down terrestrial radiation were measured on the OCEANET container placed on the monkey island. At least about 1000 time series of 1 h length were analyzed to derive bulk transfer coefficients for the fluxes of sensible and latent heat. The bulk transfer coefficients were applied to the ship's meteorological data to derive the heat fluxes at the sea surface. The reflected solar radiation was estimated from measured global radiation. The up terrestrial radiation was derived from the skin temperature according to the Stefan-Boltzmann law. Parameterized heat fluxes were compared to the widely used COARE-parameterization (Fairall et al., 2003), the agreement is excellent. Measured and parameterized heat and radiation fluxes gave the total energy budget at the air sea interface. As expected the mean total flux is positive, but there are also areas, where it is negative, indicating an energy loss of the ocean. It could be shown that the variations in the energy budget are mainly due to insolation and evaporation. A comparison between the mean values of measured and

Preface: phys. stat. sol. (a) 203/12

NASA Astrophysics Data System (ADS)

Jackman, Richard B.; Nesládek, Milo; Haenen, Ken

2006-09-01

Stefan Hildebrandt, Ron Schulz-Rheinländer, Christoph Lellig, and Julia Hübner, for their excellent and patient work, bringing the number of successfully published proceedings of SBDD in pss (a) up to 8 already!To finish, we would all like to invite you to the 12th edition of the SBDD series, newly renamed as Hasselt Diamond Workshop, to be held at its established location of Diepenbeek-Hasselt. We look forward meeting you again at SBDD XII in 2007:Hasselt Diamond Workshop - SBDD XII28 February-2 March 2007Hasselt University, Diepenbeek-Hasselt, Belgiumhttp://www.imo.uhasselt.be/SBDD2007London, Paris, Hasselt, August 2006

Experiments versus modeling of buoyant drying of porous media

NASA Astrophysics Data System (ADS)

Salin, D.; Yiotis, A.; Tajer, E.; Yortsos, Y. C.

2012-12-01

Experiments versus modeling of buoyant drying of porous media D. Salin and A.G. Yiotis, Laboratoire FAST, Univ Pierre & Marie Curie, Univ. Paris-Sud, CNRS, Orsay 91405, France and E.S. Tajer and Y.C. Yortsos, Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1450 A series of isothermal drying experiments in packed glass beads saturated with volatile hydrocarbons (hexane or pentane) are conducted. The transparent glass cells containing the packing allow for the visual monitoring of the phase distribution patterns below the surface, including the formation of liquid films, as the gaseous phase invades the pore space, and for the control of the thickness of the diffusive mass boundary layer over the packing. We demonstrate the existence of an early Constant Rate Period, CRP, that lasts as long as the films saturate the surface of the packing, and of a subsequent Falling Rate Period, FRP, that begins practically after the detachment of the film tips from the external surface. During the CRP, the process is controlled by diffusion within the stagnant gaseous phase in the upper part of the cells, yielding a Stefan tube problem solution. During the FRP, the process is controlled by diffusion within the packing, with a drying rate inversely proportional to the observed position of the film tips in the cell. The critical residual liquid saturation that marks the transition between these two regimes is found to be a function of the average bead size in our packs and the incline of the cells with respect to the flat vertical, with larger beads and angles closer to the vertical position leading to earlier film detachment times and higher critical saturations. We developed a model for the drying of porous media in the presence of gravity. It incorporated effects of corner film flow, internal and external mass transfer and the effect of gravity. Analytical results were derived when gravity opposes

Flexible Description and Adaptive Processing of Earth Observation Data through the BigEarth Platform

NASA Astrophysics Data System (ADS)

Gorgan, Dorian; Bacu, Victor; Stefanut, Teodor; Nandra, Cosmin; Mihon, Danut

2016-04-01

of some Earth Observation oriented applications based on flexible description of processing, and adaptive and portable execution over Cloud infrastructure. Main references for further information: [1] BigEarth project, http://cgis.utcluj.ro/projects/bigearth [2] Gorgan, D., "Flexible and Adaptive Processing of Earth Observation Data over High Performance Computation Architectures", International Conference and Exhibition Satellite 2015, August 17-19, Houston, Texas, USA. [3] Mihon, D., Bacu, V., Colceriu, V., Gorgan, D., "Modeling of Earth Observation Use Cases through the KEOPS System", Proceedings of the Intelligent Computer Communication and Processing (ICCP), IEEE-Press, pp. 455-460, (2015). [4] Nandra, C., Gorgan, D., "Workflow Description Language for Defining Big Earth Data Processing Tasks", Proceedings of the Intelligent Computer Communication and Processing (ICCP), IEEE-Press, pp. 461-468, (2015). [5] Bacu, V., Stefan, T., Gorgan, D., "Adaptive Processing of Earth Observation Data on Cloud Infrastructures Based on Workflow Description", Proceedings of the Intelligent Computer Communication and Processing (ICCP), IEEE-Press, pp.444-454, (2015).

Peer review statement

NASA Astrophysics Data System (ADS)

2010-08-01

All papers published in this Volume 12 of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the editors of the 25th IAHR Symposium on Hydraulic Machinery and Systems proceedings, Professor Romeo Susan-Resiga, Dr Sebastian Muntean and Dr Sandor Bernad. Reviews were conducted by expert referees from the Scientific Committee to the professional and scientific standards expected of a proceedings journal published by IOP Publishing. The members of the Scientific Committee who selected and reviewed the papers included in the Proceedings of the 25th IAHR Symposium on Hydraulic Machinery and Systems are: Anton ANTONTechnical University of Civil Engineering, BucharestRomania François AVELLANEcole Polytechnique Fédérale de LausanneSwitzerland Fidel ARZOLAEDELCAVenezuela Thomas ASCHENBRENNERVoith Hydro Gmb H & Co. KG, HeidenheimGermany Anton BERGANTLitostroj Power d.o.o., LjubljanaSlovenia Gerard BOISENSAM, LilleFrance Hermod BREKKENTNU, TrondheimNorway Stuart COULSON Voith Hydro Inc., YorkUSA Eduard EGUSQUIZAPolytechnical University Catalonia BarcelonaSpain Arpad FAYUniversity of MiskolczHungary Richard FISHERVoith Hydro Inc., York USA Regiane FORTES-PATELLAInstitut Polytechnique de GrenobleFrance Aleksandar GAJICUniversity of BelgradeSerbia Arno GEHRERAndritz Hydro GrazAustria José GONZÁLEZUniversidad de OviedoSpain François GUIBAULTEcole Polytechnique de MontrealCanada Chisachi KATOUniversity of TokyoJapan Kwang-Yong KIMInha University, IncheonKorea Jiri KOUTNIKVoith Hydro Gmb H & Co. KG, HeidenheimGermany Adrian LUNGUDunarea de Jos University of GalatiRomania Christophe NICOLETPower Vision Engineering Sàrl, LausanneSwitzerland Torbjøm K. NIELSENNTNU, TrodheimNorway Michihiro NISHIKyushu Institute of TechnologyJapan Maryse PAGEHydro Quebec IREQ, VarennesCanada Etienne PARKINSONAndritz Hydro LtdSwitzerland František POCHYLYBrno UniversityCzech Republic Stefan RIEDELBAUCHVoith Hydro Gmb H & Co. KG

Large-Scale Uncertainty and Error Analysis for Time-dependent Fluid/Structure Interactions in Wind Turbine Applications

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

Alonso, Juan J.; Iaccarino, Gianluca

2013-08-25

The following is the final report covering the entire period of this aforementioned grant, June 1, 2011 - May 31, 2013 for the portion of the effort corresponding to Stanford University (SU). SU has partnered with Sandia National Laboratories (PI: Mike S. Eldred) and Purdue University (PI: Dongbin Xiu) to complete this research project and this final report includes those contributions made by the members of the team at Stanford. Dr. Eldred is continuing his contributions to this project under a no-cost extension and his contributions to the overall effort will be detailed at a later time (once his effortmore » has concluded) on a separate project submitted by Sandia National Laboratories. At Stanford, the team is made up of Profs. Alonso, Iaccarino, and Duraisamy, post-doctoral researcher Vinod Lakshminarayan, and graduate student Santiago Padron. At Sandia National Laboratories, the team includes Michael Eldred, Matt Barone, John Jakeman, and Stefan Domino, and at Purdue University, we have Prof. Dongbin Xiu as our main collaborator. The overall objective of this project was to develop a novel, comprehensive methodology for uncertainty quantification by combining stochastic expansions (nonintrusive polynomial chaos and stochastic collocation), the adjoint approach, and fusion with experimental data to account for aleatory and epistemic uncertainties from random variable, random field, and model form sources. The expected outcomes of this activity were detailed in the proposal and are repeated here to set the stage for the results that we have generated during the time period of execution of this project: 1. The rigorous determination of an error budget comprising numerical errors in physical space and statistical errors in stochastic space and its use for optimal allocation of resources; 2. A considerable increase in efficiency when performing uncertainty quantification with a large number of uncertain variables in complex non-linear multi-physics problems; 3

An assessment toolkit to increase the resilience of NWE catchments to periods of drought

NASA Astrophysics Data System (ADS)

La Jeunesse, Isabelle; Larrue, Corinne

2013-04-01

European governance assessment toolkit to define regional drought adaptation; 2) to improve the effectiveness of drought adaptation measures for NWE areas, and 3) to enhance the preparedness of regional stakeholders in NWE in drought adaptation. In this presentation, authors aim at presenting the assessment toolkit based on a combination of five regime dimensions and four regime qualities which have been operationalized into a questionnaire. The questionnaire helps to make a regime assessment of both the static situation and the dynamics. Acknowledgments This research is funded by the INTERREG IVB programme for the North Western Europe and DROP is leaded by the Regge en Dinkel Water Board in the Netherlands. The toolkit is developped in collaboration with the University of Twente and in particular with Stefan Kuks, Hans Bressers, Cheryl de Boer, Joanne Vinke and Gül Özerol. We specially acknowledge Regional partners of DROP.

Inorganic-based proton conductive composite membranes for elevated temperature and reduced relative humidity PEM fuel cells

NASA Astrophysics Data System (ADS)

Wang, Chunmei

either by mixing inorganic gels or solutions with Nafion solution followed by membrane casting or by blending inorganic powders with Nafion solution. The membrane properties, such as acidity, swelling, water uptake, thermostability, proton conductivity, and electrochemical performance, were explored in depth. We characterized the inorganic phase inside composite membranes and its interaction with the Nafion matrix by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Furthermore, we discussed the effect of these inorganic conductors' properties, such as particle size, conductivity, and interaction between functional groups and the Nafion, on the membrane conductivity. The contribution of hydrophilic inorganic particles in improving the membrane fuel cell performance was numerically analyzed by Tafel plot. Finally, the proton conductivity phenomena in composite membranes were simulated with two proton-transport models; one was based on the rule of mixtures, and the other was described by generalized Stefan-Maxwell equations. In the simulation, we proposed a new route in rational design of high proton-conductive composite membranes.

Martin Stutzmann: Editor, Teacher, Scientist and Friend

NASA Astrophysics Data System (ADS)

Cardona, Manuel

2005-02-01

popular along these lines, a fact which moved Martin to launch in 2002 part (c) of the journal, devoted mainly, but not exclusively, to conference articles.Martin also introduced the publication of Feature Articles, topical issues, and the instrument of the Editor's Choice to highlight articles deemed to be especially interesting.He appointed Regional Editors (6 at this point) which represent the journal in important geographic regions. He also brought the journal online, a must these days.The upheavals that followed the collapse of most of the communist world, the rapid development of science in many emerging nations and the enhanced competitiveness, even in the developed countries, have not ebbed out. Some of them are particular damaging to the reputation of science in a world increasingly skeptical of its values. I am thinking of scientific misconduct and outright fraud, in the form of plagiarism and data fabrication. physica status solidi was also afflicted by this plague: after all, it happened in the best of families. Two of the most notorious offenders of the past decade, J. H. Schön and Y. Park, also visited physica status solidi. In two courageous editorials Martin Stutzmann and Stefan Hildebrandt (Managing Editor of the journal) rapidly exposed these cases of misconduct together with other cases in which there was also good reason to suspect misconduct. Some of the articles involved were rapidly retracted by the authors, others were not.It is reassuring to say that none of them had any impact worth mentioning (1-3 citations, mostly by the authors themselves or in the editorials just mentioned). Only few journal editors dared to convey to the readers a warning that some work of those authors may be faulty even if no air-tight proof was available. However, Martin and Stefan did.We wish that Martin will remain at the helm at least another decade, before he

Thermal-mechanical modeling of laser ablation hybrid machining

NASA Astrophysics Data System (ADS)

Matin, Mohammad Kaiser

2001-08-01

Hard, brittle and wear-resistant materials like ceramics pose a problem when being machined using conventional machining processes. Machining ceramics even with a diamond cutting tool is very difficult and costly. Near net-shape processes, like laser evaporation, produce micro-cracks that require extra finishing. Thus it is anticipated that ceramic machining will have to continue to be explored with new-sprung techniques before ceramic materials become commonplace. This numerical investigation results from the numerical simulations of the thermal and mechanical modeling of simultaneous material removal from hard-to-machine materials using both laser ablation and conventional tool cutting utilizing the finite element method. The model is formulated using a two dimensional, planar, computational domain. The process simulation acronymed, LAHM (Laser Ablation Hybrid Machining), uses laser energy for two purposes. The first purpose is to remove the material by ablation. The second purpose is to heat the unremoved material that lies below the ablated material in order to ``soften'' it. The softened material is then simultaneously removed by conventional machining processes. The complete solution determines the temperature distribution and stress contours within the material and tracks the moving boundary that occurs due to material ablation. The temperature distribution is used to determine the distance below the phase change surface where sufficient ``softening'' has occurred, so that a cutting tool may be used to remove additional material. The model incorporated for tracking the ablative surface does not assume an isothermal melt phase (e.g. Stefan problem) for laser ablation. Both surface absorption and volume absorption of laser energy as function of depth have been considered in the models. LAHM, from the thermal and mechanical point of view is a complex machining process involving large deformations at high strain rates, thermal effects of the laser, removal of

Environmental Challenges Related to the Acquisition of the Trans Carpathian Wide Angle Reflection and Refraction Line

NASA Astrophysics Data System (ADS)

Dragut, Dorina-Alina; Schultz, Gehrig; Mocanu, Victor; Stephenson, Randell; Janik, Tomasz; Starostenko, Vitaly

2015-04-01

technological targets while managing to obey all legal rules and regulations imposed by the decision makers. We finally demonstrate that there is no danger for the environment by this classic form of seismic wave generation if all restrictions, health and safety rules are strictly complied with and are continuously monitored. This project could not be carried out successfully without significant support from: Mark Sturgess and Mark Wigley of Hunt Oil of Romania; Alex Stefan and Radita Bandrabur of Prospectiuni; Vasile Ionel Catana and Albert Ion Ranete of Maxam Romania; Alissa Ionescu of Lukoil Romania; Gheorghe Dutu, Claudia Raileanu and Elena Caramalau of the National Agency of Mineral Resources of Romania; Laszlo Klarick of the Romanian Senate. This work has been supported from the strategic grant POSDRU/159/1.5/S/133391, Project "Doctoral and Post-doctoral programs of excellence for highly qualified human resources training for research in the field of Life sciences, Environment and Earth Science" cofinanced by the European Social Fund within the Sectorial Operational Program Human Resources Development 2007 - 2013.

Identifying and reducing the incidence of post discharge Venous Thromboembolism (VTE) in orthopaedic patients: a systematic review.

PubMed

McLiesh, Paul; Wiechula, Rick

2012-01-01

BACKGROUND: The risk of venous thromboembolism for orthopaedic patients is often high due to the length of surgery, damage from trauma to bone and soft tissues and lengthy periods of immobility or reduced mobility. Although venous thromboembolism occurs mainly in inpatients a significant number of patients develop venous thromboembolism post discharge OBJECTIVES: To synthesise the best available evidence on strategies that effectively reduce post discharge venous thromboembolism in orthopaedic patients. INCLUSION CRITERIA: Patients regardless of age, gender or co-morbidities that have been admitted with an acute orthopaedic injury (unplanned) or a planned orthopaedic surgery/procedure and then followed up after discharge. Only papers describing the incidence and prophylaxis treatment used in non-Asian patients were considered for inclusion. Any interventions of combinations of chemoprophylaxis and/or mechanical prophylaxis to prevent venous thromboembolism incidence extending beyond hospital admission. Outcomes included diagnosis of venous thromboembolism following an orthopaedic admission/surgery for up to 6 months post discharge and the incidence of any significant bleeding or death related to venous thromboembolism or haemorrhage.The review considered any randomised controlled trials; in the absence of RCTs other research designs, such as non-randomised controlled trials and before and after studies, were considered SEARCH STRATEGY: Search strategy considered only papers in English from 2000 to March 2012. METHODOLOGICAL QUALITY: Papers selected for retrieval were assessed using standardised critical appraisal instruments from the Joanna Briggs Institute. DATA COLLECTION: Data was extracted from the studies using the standardised Johanna Briggs Institute data extraction form. DATA SYNTHESIS: Of the included studies none matched methodology, treatment or comparator that allowed meta-analysis. The results were therefore presented in a narrative form and were

PREFACE New developments in nanopore research—from fundamentals to applications New developments in nanopore research—from fundamentals to applications

NASA Astrophysics Data System (ADS)

Albrecht, Tim; Edel, Joshua B.; Winterhalter, Mathias

2010-11-01

refereeing process, and Ms Natalia Goehring for the beautiful cover artwork. Finally, to the readers, we hope you find this special issue a valuable source of information and insight into the field of nanopores. New developments in nanopore research—from fundamentals to applications contents Mathematical modeling and simulation of nanopore blocking by precipitation M-T Wolfram, M Burger and Z S Siwy Protein conducting nanopores Anke Harsman, Vivien Krüger, Philipp Bartsch, Alf Honigmann, Oliver Schmidt, Sanjana Rao, Christof Meisinger and Richard Wagner Electrically sensing protease activity with nanopores Mikiembo Kukwikila and Stefan Howorka Electrical characterization of DNA-functionalized solid state nanopores for bio-sensing V Mussi, P Fanzio, L Repetto, G Firpo, P Scaruffi, S Stigliani, M Menotta, M Magnani, G P Tonini and U Valbusa Automatable lipid bilayer formation and ion channel measurement using sessile droplets J L Poulos, S A Portonovo, H Bang and J J Schmidt Critical assessment of OmpF channel selectivity: merging information from different experimental protocols M L López, E García-Giménez, V M Aguilella and A Alcaraz Chemically modified solid state nanopores for high throughput nanoparticle separation Anmiv S Prabhu, Talukder Zaki N Jubery, Kevin J Freedman, Rafael Mulero, Prashanta Dutta and Min Jun Kim Changes in ion channel geometry resolved to sub-ångström precision via single molecule mass spectrometry Joseph W F Robertson, John J Kasianowicz and Joseph E Reiner Entropic transport of finite size particles W Riefler, G Schmid, P S Burada and P Hänggi Osmotic stress regulates the strength and kinetics of sugar binding to the maltoporin channel Philip A Gurnev, Daniel Harries, V Adrian Parsegian and Sergey M Bezrukov Detection of urea-induced internal denaturation of dsDNA using solid-state nanoporesn Alon Singer, Heiko Kuhn, Maxim Frank-Kamenetskii and Amit Meller Translocation events in a single-walled carbon nanotube Jin He, Hao Liu, Pei Pang

EDITORIAL: From reciprocal space to real space in surface science From reciprocal space to real space in surface science

NASA Astrophysics Data System (ADS)

Bartels, Ludwig; Ernst, Karl-Heinz

2012-09-01

Triest.let's finish—aus basta Some move atoms around to hear how they sound.Karl-Heinz Rieder, Erice, 6 April 1998 From reciprocal space to real space in surface science contents From reciprocal space to real space in surface scienceLudwig Bartels and Karl-Heinz Ernst Karl-Heinz Reider: the quiet pioneerGiorgio Benedek Scattering of CO and N2 molecules by a graphite surfaceJunepyo Oh, Takahiro Kondo, Keitaro Arakawa, Yoshihiko Saito, Junji Nakamura, W W Hayes and J R Manson Helium, neon and argon diffraction from Ru(0001)M Minniti, C Díaz, J L Fernández Cuñado, A Politano, D Maccariello, F Martín, D Farías and R Miranda Enhanced charge transfer in a monolayer of the organic charge transfer complex TTF-TNAP on Au(111)T R Umbach, I Fernandez-Torrente, J N Ladenthin, J I Pascual and K J Franke Extended pattern recognition scheme for self-learning kinetic Monte Carlo simulationsSyed Islamuddin Shah, Giridhar Nandipati, Abdelkader Kara and Talat S Rahman Acetylene on Cu(111): imaging a molecular surface arrangement with a constantly rearranging tipYeming Zhu, Jonathan Wyrick, Kamelia D Cohen, Katie Marie Magnone, Connor Holzke, Daniel Salib, Quan Ma, Dezheng Sun and Ludwig Bartels Coulomb attraction during the carpet growth mode of NaClFriederike Matthaei, Sarah Heidorn, Konrad Boom, Cord Bertram, Ali Safiei, Jörg Henzl and Karina Morgenstern Molecular self-assembly on an insulating surface: interplay between substrate templating and intermolecular interactionsMarkus Kittelmann, Philipp Rahe and Angelika Kühnle Vertical manipulation of native adatoms on the InAs(111)A surfaceJ Yang, C Nacci, J Martínez-Blanco, K Kanisawa and S Fölsch Charge transfer between isomer domains on n+-doped Si(111)-2 × 1: energetic stabilizationR M Feenstra, G Bussetti, B Bonanni, A Violante, C Goletti, P Chiaradia, M G Betti and C Mariani Probing the properties of metal-oxide interfaces: silica films on Mo and Ru supportsLeonid Lichtenstein, Markus Heyde, Stefan Ulrich, Niklas Nilius

PREFACE: The 4th Symposium on the Mechanics of Slender Structures (MoSS2013)

NASA Astrophysics Data System (ADS)

Cao, Dengqing; Kaczmarczyk, Stefan

2013-07-01

; in cable-supported bridges, guyed masts and long-span roofs of buildings and stadia. Suspended cables are also applied as electricity transmission lines. Chains are used in various power transmission systems that include such mechanical systems as chain drives and chain saws. Moving conveyor belts are essential components in various material handling installations. Other structures such as pipelines, plates, beams, mechanical linkages and DNA structures also fall into this category. The behaviour of these elements plays a significant role in the performance of the host structure and a holistic approach is needed in the analysis and design of the entire system. This meeting brings together experts from various fields: structural mechanics, thermo-mechanics, dynamics, electrodynamics, vibration and control, structural health monitoring, artificial intelligence, materials science and applied mathematics to discuss the current state of research as well as rising trends and direction for future research in the area of mechanics of slender structures. The event is aimed at improving the understanding of structural and thermo-mechanical properties and behaviour of slender structures. The papers presented at the conference cover analytical, numerical and experimental research in various applications of slender structures. The Organizing Committee gratefully acknowledges support received from the co-sponsoring institutions and would like to thank the authors for their hard work and high quality contributions. Dengqing Cao Harbin Institute of Technology Stefan Kaczmarczyk The University of Northampton

Ivrea mantle wedge and arc of the Western Alps (II): Kinematic evolution of the Alps-Apennines orogenic system

NASA Astrophysics Data System (ADS)

Schmid, Stefan; Kissling, Eduard; van Hinsbergen, Douwe J. J.; Molli, Giancarlo

2017-04-01

lateral transition from continent-continent collision in the Central and Eastern Alps to intra-oceanic subduction in the Western Alps during Alpine orogeny, leaving large parts of the Piemont-Liguria Ocean that belong to the Adria microplate open until about 25 Ma. It is these parts that from now on formed the highest tectonic units in the Apennines, namely the Ligurides. However, internal units of the Northern Apennines previously suffered Alpine-type shortening associated with an E-dipping Alpine subduction zone. They became " backthrusted" to the NE during Apenninic orogeny commencing in the Late Oligocene. Apenninic orogeny is associated with a change in subduction polarity from Alpine E-directed subduction, previously affecting the Internal Ligurides and other parts of the Northern Apennines, towards NW-directed subduction and roll back of the Adria slab beneath Northern Apennines, pulled by the negative buoyancy of those parts of the old oceanic lithosphere of the Piemont-Liguria Ocean that remained unaffected by Alpine orogeny. Reference: Edi Kissling, Stefan M. Schmid, Tobias Diehl (2017). Ivrea mantle wedge and arc of the Western Alps (1): Geophysical evidence for the deep structure. Abstract Volume EGU 2017.

Geomorphological change detection of fluvial processes of lower Siret channel using LIDAR data

NASA Astrophysics Data System (ADS)

Niculita, Mihai; Obreja, Florin; Boca, Bogdan

2015-04-01

:121-134. Lague D., Brodu N., Leroux J., 2013. Accurate 3D comparison of complex topography with terrestrial laser scanner: application to the Rangitikei canyon (N-Z), ISPRS journal of Photogrammmetry and Remote Sensing, 80:10-26. James L.A., Hodgson M.E., Ghoshal S., Latiolais M.M., 2012. Geomorphic change detection using historic maps and DEM differencing: the temporal dimension of geospatial analysis. Geomorphology, 137:181-198. Nedelcu G., Borcan M., Branescu E., Petre C., Teleanu B., Preda A., Murafa R., 2011. Exceptional floods from the years 2008 and 2010 in Siret river basin, Proceedings of the Annual Scientific Conference of National Romanian Institute of Hydrology and Water Administration, 1-3 November 2011. (in Romanian) Olariu P., Obreja F., Obreja I., 2009. Some aspects regarding the sediment transit from Trotus catchment and lower sector of Siret river during the exceptional floods from 1991 and 2005, Annals of Stefan cel Mare University of Suceava, XVIII:93-104.(in Romanian) Serbu M., Obreja F., Olariu P., 2009. The 2008 floods from upper Siret catchment. Causes, effects, evaluation, Hidrotechnics, 54(12):1-38. (in Romanian) Wheaton J.M., Brasington J., Darby S., Sear D., 2009. Accounting for uncertainty in DEMs from repeat topographic surveys: improved sediment budgets. Earth Surface Processes and Landforms, 35(2):136-156.

Population Size Estimation of Gay and Bisexual Men and Other Men Who Have Sex With Men Using Social Media-Based Platforms.

PubMed

Baral, Stefan; Turner, Rachael M; Lyons, Carrie E; Howell, Sean; Honermann, Brian; Garner, Alex; Hess, Robert; Diouf, Daouda; Ayala, George; Sullivan, Patrick S; Millett, Greg

2018-02-08

proportions to those of older men. There is greater consistency in Facebook estimates of GBMSM compared to UNAIDS-reported estimates across countries. The ability to use social media for epidemiologic and HIV prevention, treatment, and care needs continues to improve. Here, a method leveraging different categories of same-sex interests on Facebook, combined with a specific gay-oriented app (Hornet), demonstrated significantly higher estimates than those officially reported. While there are biases in this approach, these data reinforce the need for multiple methods to be used to count the number of GBMSM (especially in more stigmatizing settings) to better inform mathematical models and the scale of HIV program coverage. Moreover, these estimates can inform programs for those aged 13-17 years; a group for which HIV incidence is the highest and HIV prevention program coverage, including the availability of pre-exposure prophylaxis (PrEP), is lowest. Taken together, these results highlight the potential for social media to provide comparable estimates of the number of GBMSM across a large range of countries, including some with no reported estimates. ©Stefan Baral, Rachael M Turner, Carrie E Lyons, Sean Howell, Brian Honermann, Alex Garner, Robert Hess III, Daouda Diouf, George Ayala, Patrick S Sullivan, Greg Millett. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 08.02.2018.

The Multimodal Assessment of Adult Attachment Security: Developing the Biometric Attachment Test.

PubMed

Parra, Federico; Miljkovitch, Raphaële; Persiaux, Gwenaelle; Morales, Michelle; Scherer, Stefan

2017-04-06

for correlations with attachment security. The stability of the theory-consistent features across three different stimuli sets was explored using repeated measures analysis of variances (ANOVAs). In total, 46 theory-consistent correlations were found during the exploration (out of 65 total significant correlations). For example, attachment security as measured by the AAP was correlated with positive facial expressions (r=.36, P=.01). AMMI's security with the father was inversely correlated with the low frequency (LF) of HRV (r=-.87, P=.03). Attachment security to partners as measured by the AAQ was inversely correlated with anger facial expression (r=-.43, P=.001). The confirmatory analysis showed that the composite effects index was significantly correlated to security in the AAP (r=.26, P=.05) and the AAQ (r=.30, P=.04) but not in the AMMI. Repeated measures ANOVAs conducted individually on each of the theory-consistent features revealed that only 7 of the 46 (15%) features had significantly different values among responses to three different stimuli sets. We were able to validate two of the instrument's core assumptions: its capacity to measure attachment security and the viability of using themes as placeholders for rotating stimuli. Future validation of other of its dimensions, as well as the ongoing development of its scoring and classification algorithms is discussed. ©Federico Parra, Raphaële Miljkovitch, Gwenaelle Persiaux, Michelle Morales, Stefan Scherer. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 06.04.2017.

PREFACE: Atomically controlled fabrication technology: new physics and functional device realization Atomically controlled fabrication technology: new physics and functional device realization

NASA Astrophysics Data System (ADS)

Kuwahara, Yuji; Kasai, Hideaki

2011-10-01

, J L Hutchison, D C Smith, P Ashburn and C H de Groot Mechanism of atomic-scale passivation and flattening of semiconductor surfaces by wet-chemical preparationsKenta Arima, Katsuyoshi Endo, Kazuto Yamauchi, Kikuji Hirose, Tomoya Ono and Yasuhisa Sano Real-space calculations for electron transport properties of nanostructuresTomoya Ono, Shigeru Tsukamoto, Yoshiyuki Egami and Yoshitaka Fujimoto Thermally activated magnetization reversal in monatomic magnetic chains on surfaces studied by classical atomistic spin-dynamics simulationsDavid S G Bauer, Phivos Mavropoulos, Samir Lounis and Stefan Blügel An atomically controlled Si film formation process at low temperatures using atmospheric-pressure VHF plasmaK Yasutake, H Kakiuchi, H Ohmi, K Inagaki, Y Oshikane and M Nakano Single-nanometer focusing of hard x-rays by Kirkpatrick-Baez mirrorsKazuto Yamauchi, Hidekazu Mimura, Takashi Kimura, Hirokatsu Yumoto, Soichiro Handa, Satoshi Matsuyama, Kenta Arima, Yasuhisa Sano, Kazuya Yamamura, Koji Inagaki, Hiroki Nakamori, Jangwoo Kim, Kenji Tamasaku, Yoshinori Nishino, Makina Yabashi and Tetsuya Ishikawa Surface magnetism in O2 dissociation—from basics to applicationY Kunisada, M C Escaño and H Kasai Real-space finite-difference approach for multi-body systems: path-integral renormalization group method and direct energy minimization methodAkira Sasaki, Masashi Kojo, Kikuji Hirose and Hidekazu Goto Electrical conduction of organic ultrathin films evaluated by an independently driven double-tip scanning tunneling microscopeK Takami, S Tsuruta, Y Miyake, M Akai-Kasaya, A Saito, M Aono and Y Kuwahara

A Skin Cancer Prevention Facial-Aging Mobile App for Secondary Schools in Brazil: Appearance-Focused Interventional Study.

PubMed

Brinker, Titus Josef; Heckl, Marlene; Gatzka, Martina; Heppt, Markus V; Resende Rodrigues, Henrique; Schneider, Sven; Sondermann, Wiebke; de Almeida E Silva, Carolina; Kirchberger, Michael C; Klode, Joachim; Enk, Alexander H; Knispel, Sarah; von Kalle, Christof; Stoffels, Ingo; Schadendorf, Dirk; Nakamura, Yasuhiro; Esser, Stefan; Assis, Aisllan; Bernardes-Souza, Breno

2018-03-09

, 87.2% agreement in males) and increased use of sun protection (n=197, 92.1% agreement in females vs n=123, 87.2% agreement in males) and independent of age or skin type. All medical students involved filled in a process evaluation revealing that they all perceived the intervention as effective and unproblematic, and that all pupils tried the app in their presence. The photoaging intervention was effective in changing behavioral predictors for UV protection in Brazilian adolescents. The predictors measured indicated an even higher prospective effectiveness in southeast Brazil than in Germany (>90% agreement in Brazil vs >60% agreement in Germany to both items that measured motivation to reduce UV exposure) in accordance with the theory of planned behavior. Medical students are capable of complete implementation. A randomized controlled trial measuring prospective effects in Brazil is planned as a result of this study. ©Titus Josef Brinker, Marlene Heckl, Martina Gatzka, Markus V Heppt, Henrique Resende Rodrigues, Sven Schneider, Wiebke Sondermann, Carolina de Almeida e Silva, Michael C Kirchberger, Joachim Klode, Alexander H Enk, Sarah Knispel, Christof von Kalle, Ingo Stoffels, Dirk Schadendorf, Yasuhiro Nakamura, Stefan Esser, Aisllan Assis, Breno Bernardes-Souza. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 09.03.2018.

The Kosice meteorite

NASA Astrophysics Data System (ADS)

Toth, J.; Svoren, J.

2012-01-01

Sciences (under the leadership of the second author), Comenius University in Bratislava (under the leadership of the first author), and the Czech Academy of Sciences (under the leadership of Pavel Spurny) started to sweep meadows and forests at the calculated area. The first meteorite was discovered by Juraj Toth on March 20th. By October 6th, 77 meteorite fragments were found. The heaviest fragment weighs 2.17 kg and was found by Tereza Krejcova; the smallest pieces were only about 0.5 g (finder Julius Koza). The total mass recovered is 4.3 kg. There were 28 finders: Juraj Toth, Diana Buzova, Marek Husarik, Tereza Krejcova, Jan Svoren, Julius Koza, David Capek, Pavel Spurny, Stanislav Kaniansky, Eva Schunova, Marcel Skreka, Dusan Tomko, Pavol Zigo, Miroslav Seben, Jiri Silha, Leonard Kornos, Marcela Bodnarova, Peter Veres, Jozef Nedoroscik, Zuzana Mimovicova, Zuzana Krisandova, Jaromir Petrzala, Stefan Gajdos, Tomas Dobrovodsky, Peter Delincak, Zdenko Bartos, Ales Kucera, and Jozef Vilagi. Preliminary as well as complex mineralogic analysis implies that the recovered meteorite is classified as an ordinary H5 chondrite (Dr. J. Haloda, Czech Geological Survey, D. Ozdin, and P. Uher, Comenius University in Bratislava). The authors are grateful to all collaborators mentioned above. More details about the meteorite will be published in the near future.

Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling.

PubMed

Rao, Amrita; Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

2017-10-20

samples. In addition, RDS samples indicated lower exposure to HIV prevention information, less knowledge about HIV prevention, limited access to HIV prevention tools such as condoms, and less-reported frequency of sexually transmitted infections (STI) and HIV testing as compared with the venue-based samples. Findings pertaining to the level of disclosure of sexual practices and sexual practice-related stigma were mixed. Samples generated by RDS and venue-based snowball sampling produced significantly different prevalence estimates of several important characteristics. These findings are tempered by limitations to the application of both approaches in practice. Ultimately, these findings provide further context for understanding existing surveillance data and how differences in methods of sampling can influence both the type of individuals captured and whether or not these individuals are representative of the larger target population. These data highlight the need to consider how program coverage estimates of marginalized populations are determined when characterizing the level of unmet need. ©Amrita Rao, Shauna Stahlman, James Hargreaves, Sharon Weir, Jessie Edwards, Duncan Kochelani, Duncan Kochelani, Mpumelelo Mavimbela, Stefan Baral. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 20.10.2017.

The Parasol Protocol: An Implementation Science Study of HIV Continuum of Care Interventions for Gay Men and Transgender Women in Burma/Myanmar.

PubMed

Wirtz, Andrea L; Naing, Soe; Clouse, Emily; Thu, Kaung Htet; Mon, Sandra Hsu Hnin; Tun, Zin Min; Baral, Stefan; Paing, Aung Zayar; Beyrer, Chris

2017-05-17

. Aims 2 and 3 participants will be prospectively followed for 12 months with data collection including interviewer-administered sociobehavioral survey, CD4 POC, and viral load testing occurring biannually. Participants who accept peer navigation will be compared to those who decline peer navigation. Analyses will estimate the impact of CD4 POC on engagement in care and the impact of peer navigation on ART adherence and viral load. Formative qualitative research was conducted in June and September 2015 and led to further refinement of recruitment methods, HIVST instructions and counseling, and peer navigation methods. Aim 1 recruitment began in November 2015 with subsequent enrollment into Aims 2 and 3 and is currently ongoing. These innovative interventions may resolve gaps in the HIV care continuum among MSM and TW and future implementation may aid in curbing the HIV epidemic among MSM and TW in Myanmar. ©Andrea L Wirtz, Soe Naing, Emily Clouse, Kaung Htet Thu, Sandra Hsu Hnin Mon, Zin Min Tun, Stefan Baral, Aung Zayar Paing, Chris Beyrer. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 17.05.2017.

PREFACE: Wake Conference 2015

NASA Astrophysics Data System (ADS)

Barney, Andrew; Nørkær Sørensen, Jens; Ivanell, Stefan

2015-06-01

at scientists and PhD students working in the field of wake dynamics. The conference covers the following subject areas: Wake and vortex dynamics, instabilities in trailing vortices and wakes, simulation and measurements of wakes, analytical approaches for modeling wakes, wake interaction and other wind farm investigations. Many people have been involved in producing the 2015 Wake Conference proceedings. The work by the more than 60 reviewers ensuring the quality of the papers is greatly appreciated. The timely evaluation and coordination of the reviews would not have been possible without the work of the section editors: Christian Masson, ÉTS, Fernando Porté-Agel, EPFL, Gerard Schepers, ECN Wind Energy, Gijs Van Kuik, Delft University, Gunner Larsen, DTU Wind Energy, Jakob Mann, DTU Wind Energy, Javier Sanz Rodrigo, CENER, Johan Meyers, KU Leuven, Rebecca Barthelmie, Cornell University, Sandrine Aubrun-Sanches, Université d'Orléans and Thomas Leweke, IRPHE-CNRS. We are also immensely indebted to the very responsive support from the editorial team at IOP Publishing, especially Sarah Toms, during the review process of these proceedings. Visby, Sweden, June 2015 Andrew Barney, Jens Nørkær Sørensen and Stefan Ivanell Uppsala University - Campus Gotland

PREFACE: DISCRETE 2012 - Third Symposium on Prospects in the Physics of Discrete Symmetries

NASA Astrophysics Data System (ADS)

Branco, G. C.; Emmanuel-Costa, D.; González Felipe, R.; Joaquim, F. R.; Lavoura, L.; Palomares-Ruiz, S.; Rebelo, M. N.; Romão, J. C.; Silva, J. P.

2013-07-01

Romão, J P Silva and J I Silva-Marcos International Advisory CommitteeLocal Organising Committee Francisco del Águila (Granada)From CFTP Jose Bernabéu (Valencia) Francisco Botella (Valencia)G C Branco Andrzej Buras (Munich)D Emmanuel-Costa Marcos Cerrada (Madrid)R González Felipe Pierluigi Campana (CERN)F R Joaquim Antonio Di Domenico (Rome)L Lavoura John Ellis (CERN)S Palomares-Ruiz Fernando Ferroni (Rome)M N Rebelo Luis Garrido (Barcelona)J C Romão Marcello Giorgi (Pisa)J P Silva Neville Harnew (Oxford)J I Silva-Marcos Maria José Herrero (Madrid) David Hitlin (Caltech)From LIP Gino Isidori (Frascati) Guido Martinelli (Rome)G Barreira Antonio Masiero (Padua)J Varela Nickolaos Mavromatos (London) Vasiliki Mitsou (Valencia) Hitoshi Murayama (Berkeley) Tatsuya Nakada (Lausanne) Antonio Pich (Valencia) Apostolos Pilaftsis (Manchester) Stefan Pokorski (Warsaw) Fabio Zwirner (Padua) Secretariat Dulce Conceição Sandra Oliveira Cláudia Romão discrete2012@cftp.ist.utl.pt http://indico.cern.ch/event/discrete2012 Sponsors CFTP - Centro de Física Teórica de Partículas LIP - Laboratório de Instrumentação e Física Experimental de Partículas IST - Instituto Superior Técnico FCT - Fundação para a Ciência e a Tecnologia Group picture The PDF also contains the conference poster and a list of participants.

PREFACE: Fundamental Neutron Physics: Introduction and Overview Fundamental Neutron Physics: Introduction and Overview

NASA Astrophysics Data System (ADS)

Holstein, Barry R.

2009-10-01

fundamental nature, the structure of the neutron itself can be used to probe hadronic structure, via measurement of its electromagnetic form factors and/or polarizabilities. This aspect of neutron physics is discussed in the article by Daniel Phillips. In a set of measurements at Grenoble, the neutron has been used to study its quantum mechanical gravitational bound state in the vicinity of the Earth's surface. This work is described in the article by Stefan Baessler. Finally, possible beyond standard model physics is probed by experimental searches for neutron-antineutron oscillations, as discussed in the article by Rabi Mohaptatra. There exist many other areas wherein the neutron has been used as a probe of fundamental pieces of contemporary physics. Examples include the use of neutron interferometry to measure the Earth's rotation and gravitational field and the recent use of light cone methods to study the transverse charge distribution of the neutron. Indeed, a full report on all such aspects could fill an entire volume of Journal of Physics G: Nuclear and Particle Physics. The six articles which appear here in this focus section are presented rather as a brief overview, to possibly whet the appetite of the reader for such work. Hungrier readers can fill their plate with additional and more detailed information available in the many references cited by the focus articles or in more extensive discussions available elsewhere. An example is the article on experiments in fundamental neutron physics by Jeff Nico and Mike Snow published in Annual Reviews of Nuclear and Particle Science 2005 55 27-69, but there are many others.

How Do Galaxies Grow?

NASA Astrophysics Data System (ADS)

2008-08-01

to the most massive galaxies belonging to clusters. "Most surprising is that in three of the four groups, the brightest galaxy also has a bright companion galaxy. These galaxy pairs are merging systems," says Tran. The brightest galaxy in each group can be ordered in a time sequence that shows how luminous galaxies continue to grow by merging until recently, that is, in the last 5 billion years. It appears that due to the most recent episode of this 'galactic cannibalism', the brightest galaxies became at least 50% more massive. This discovery provides unique and powerful validation of hierarchical formation as manifested in both galaxy and cluster assembly. "The stars in these galaxies are already old and so we must conclude that the recent merging did not produce a new generation of stars," concludes Tran. "Most of the stars in these galaxies were born at least 7 billion years ago." The team is composed of Kim-Vy H. Tran (Institute for Theoretical Physics, University of Zürich, Switzerland), John Moustakas (New York University, USA), Anthony H. Gonzalez and Stefan J. Kautsch (University of Florida, Gainesville, USA), and Lei Bai and Dennis Zaritsky (Steward Observatory, University of Arizona, USA). The results presented here are published in the Astrophysical Journal Letters: "The Late Stellar Assembly Of Massive Cluster Galaxies Via Major Merging", by Tran et al.

Reconstructing air temperature and permafrost attributes associated with past periglacial structures: a case study for sorted nets from the Krkonoše Mts., Czech Republic

NASA Astrophysics Data System (ADS)

Uxa, Tomáš; Křížek, Marek; Krause, David

2017-04-01

infer the palaeo-temperature and palaeo-permafrost conditions associated with relict large-scale sorted nets in the Krkonoše Mts., Czech Republic. To achieve this, we employ a multi-disciplinary approach consisting of the Monte Carlo simulation based on a simple equilibrium thermal model, the Stefan equation, in an inverse form, driven by data obtained from remote sensing, geophysical soundings, and modern analogues from elsewhere. The results are subjected to a comprehensive uncertainty and sensitivity analysis. We introduce a robust, yet straightforward and easy-to-follow procedure to utilize these periglacial phenomena and other structures indicative of the base of palaeo-active layer to reconstruct former climate. Acknowledgement The research is supported by the Czech Science Foundation, project number 17-21612S. References Ballantyne, C. K., and Harris, C.: The Periglaciation of Great Britain, Cambridge University Press, Cambridge, UK, 1994. Gleason, K. J., Krantz, W. B., Caine, N., George, J. H., and Gunn, R. D.: Geometrical Aspects of Sorted Patterned Ground in Recurrently Frozen Soil, Science, 232, 216-220, doi: 10.1126/science.232.4747.216, 1986. Hallet, B., and Prestrud, S.: Dynamics of periglacial sorted circles in Western Spitsbergen, Quaternary Res., 26, 81-99, doi: 10.1016/0033-5894(86)90085-2, 1986. Ray, R. J., Krantz, W. B., Caine, T. N., and Gunn, R. D.: A model for sorted patterned-ground regularity, J. Glaciol., 29, 317-337, doi: 10.3198/1983JoG29-102-317-337, 1983. Peterson, R. A., and Krantz, W. B.: Differential frost heave model for patterned ground formation: Corroboration with observations along a North American arctic transect, J. Geophys. Res., 113, G03S04, doi: 10.1029/2007JG000559, 2008.

Thermal Imaging Performance of TIR Onboard the Hayabusa2 Spacecraft

NASA Astrophysics Data System (ADS)

Arai, Takehiko; Nakamura, Tomoki; Tanaka, Satoshi; Demura, Hirohide; Ogawa, Yoshiko; Sakatani, Naoya; Horikawa, Yamato; Senshu, Hiroki; Fukuhara, Tetsuya; Okada, Tatsuaki

2017-07-01

temperature of 50°C in the thermal images obtained by TIR. If the spatial distribution of the temperature is caused by the variation of the thermal emissivity, including the effects of the surface roughness, the difference of the thermal emissivity Δ ɛ is estimated to be approximately 0.08, as calculated by the Stefan-Boltzmann raw. Otherwise, if the distribution of temperature is caused by the variation of the thermal inertia, the difference of the thermal inertia Δ Γ is calculated to be approximately 150 J m^{-2} s^{0.5} K^{-1}, based on a simulation using a 20-layer model of the heat balance equation. The imaging performance of TIR based on the results of the meteorite experiments indicates that TIR can resolve the spatial distribution of thermal emissivity and thermal inertia of the asteroid surface within accuracies of Δ ɛ \\cong 0.02 and Δ Γ \\cong 20 J m^{-2} s^{0.5} K^{-1}, respectively. However, the effects of the thermal emissivity and thermal inertia will degenerate in thermal images of TIR. Therefore, TIR will observe the same areas of the asteroid surface numerous times ({>}10 times, in order to ensure statistical significance), which allows us to determine both the parameters of the surface thermal emissivity and the thermal inertia by least-squares fitting to a thermal model of Ryugu.

Disinformation squared: was the HIV-from-Fort-Detrick myth a Stasi success?

PubMed

Geissler, Erhard; Sprinkle, Robert Hunt

2013-01-01

When in May 1983 the acquired immunodeficiency syndrome (AIDS) was first securely attributed to a virus, eventually called the human immunodeficiency virus (HIV), many controversies arose. Among these was one centering on HIV's origin. A startling hypothesis, called here the "HIV-from-Fort-Detrick myth," asserted that HIV had been a product, accidental or intentional, of bioweaponry research. While its earliest identifiable contributors were in the West, this myth's most dynamic propagators were in the East. The Soviet security service, the KGB, took "active measures" to create and disseminate AIDS disinformation beginning no later than July 1983 and ending no earlier than October 1987. The East German security service, a complex bureaucracy popularly known as "the Stasi," was involved, too, but how early, how deeply, how uniformly, how ably, and how successfully has not been clear. Following German reunification, claims arose attributing to the Stasi the masterful execution of ingenious elements in a disinformation campaign they helped shape and soon came to dominate. We have tested these claims. Was the HIV-from-Fort-Detrick myth a Stasi success? Primary sources were documents and photographs assembled by the Ministry of State Security (MfS) of the German Democratic Republic (GDR or East Germany), the Ministry of Interior of the People's Republic of Bulgaria, and the United States Department of State; the estate of myth principals Jakob and Lilli Segal; the "AIDS box" in the estate of East German literary figure Stefan Heym; participant-observer recollections, interviews, and correspondence; and expert interviews. We examined secondary sources in light of primary sources. The HIV-from-Fort-Detrick myth had debuted in print in India in 1983 and had been described in publications worldwide prior to 1986, the earliest year for which we found any Stasi document mentioning the myth in any context. Many of the myth's exponents were seemingly independent conspiracy

An Analog Earth Climate Model

NASA Astrophysics Data System (ADS)

Varekamp, J. C.

2010-12-01

experiment. For each time increment the radiative heat loss of the sphere is calculated from the Stefan Boltzman expression using the observed temperature at that time. The heating of the ‘earth sphere’ is accounted for in the energy balance equation by applying the temperature increase per time increment with the specific heat of bronze. The remaining energy term is the sum of the convective cooling and greenhouse effect. The heat budgets of the cooling trajectories were calculated analogous, with radiative and convective cooling causing the temperature drop per time increment. The greenhouse component again is lumped with the convective term. Equilibrium temperatures of 50-70 C were reached, with ambient temperature at 22 C. Somewhat surprising, experiments with radiatively neutral pure Argon gas yielded the highest equilibrium temperatures. Argon had the lowest specific heat of the gases used, and the observed equilibrium temperatures for different cell gases broadly scaled inversely with the heat capacity of those gases. Apparently, the efficiency of the free convective cooling strongly impacts the equilibrium temperatures. The greenhouse effects possibly have only a minor impact on final temperature as a result of the short cell pathlength. Experiments at higher cell filling pressures may provide more insight in this.

Voluminous Icelandic Basaltic Eruptions Appear To Cause Abrupt Global Warming

NASA Astrophysics Data System (ADS)

Ward, P. L.

2011-12-01

Beginning on June 21, 1783, Laki volcano in southern Iceland erupted 14.7 km3 basalt, ejecting 24 Mt SO_{2} into the stratosphere where it was blown eastward and northward and 98 Mt into the troposphere where the jet stream transported it southeastward to Europe. The "dry fog" observed in Europe with an estimated mean concentration of 60 ppbv SO2, raised daytime temperatures as much as 3.3^{o}C, causing the warmest July in England from 1659 when measurements began until 1983. SO2, tropospheric O_{3}, NO2, and fine ash absorb ultraviolet energy from the sun that causes the bonds between and within their atoms to oscillate at 47 times higher frequency than the bonds in CO_{2} absorbing infrared radiation. Temperature is proportional to the kinetic energy of these oscillations, i.e. the frequency squared. Thus these gases are raised to much higher temperatures than greenhouse gases. The Stefan-Boltzmann law says that radiation from these molecules is a constant times temperature raised to the fourth power. As a result, SO2 and ash radiate far more energy back to earth than CO_{2}, causing warming. Another way to look at the energy involved shows that 15 ppbv SO2 in the 0.3-0.42 μm wavelength band absorbs as much solar energy per unit volume as 388,000 ppbv CO_{2} absorbs infrared energy in the 12.7-17.5 μm band. Basaltic volcanoes such as Laki emit 10 to 100 times more SO2 than more evolved magmas and are less explosive, leaving most of the SO_{2} in the troposphere. All 14 Dansgaard-Oeschger (DO) sudden warmings between 46 and 11 ka are contemporaneous with the highest levels of sulfate in the GISP2 drill hole near Summit Greenland. These DO events typically warmed the northern hemisphere out of the ice age within decades, but as volcanism waned, ocean temperatures cooled the world back into an ice age within centuries. The world finally exited the ice age when voluminous volcanism continued from 11.6 to 9.6 ka. Basaltic table mountains or tuyas in Iceland document

Direct numerical simulation of droplet-laden isotropic turbulence

NASA Astrophysics Data System (ADS)

Dodd, Michael S.

us to explain the pathways for TKE exchange between the carrier turbulent flow and the flow inside the droplet. We also explain the role of the interfacial surface energy in the two-fluid TKE equation through work performed by surface tension. Furthermore, we derive the relationship between the power of surface tension and the rate of change of total droplet surface area. This link allows us to explain how droplet deformation, breakup and coalescence play roles in the temporal evolution of TKE. We then extend the code for non-evaporating droplets and develop a combined VoF method and low-Mach-number approach to simulate evaporating and condensing droplets. The two main novelties of the method are: (i) the VOF algorithm captures the motion of the liquid gas interface in the presence of mass transfer due to evaporation and condensation without requiring a projection step for the liquid velocity, and (ii) the low-Mach-number approach allows for local volume changes caused by phase change while the total volume of the liquid-gas system is constant. The method is verified against an analytical solution for a Stefan flow problem, and the D2 law is verified for a single droplet in quiescent gas. Finally, we perform DNS of an evaporating liquid droplet in forced isotropic turbulence. We show that the method accurately captures the temperature and vapor fields in the turbulent regime, and that the local evaporation rate can vary along the droplet surface depending on the structure of the surrounding vapor cloud. We also report the time evolution of the mean Sherwood number, which indicates that turbulence enhances the vaporization rate of liquid droplets.

On the Analysis of the Printing Nip on Sheetfed Lithographic Presses and its Implications on the Runnability of Common Substrates

NASA Astrophysics Data System (ADS)

Diaz, Francisco J.

This dissertation is based on the thesis that: Adequate analysis of the offset printing nip, under proper solutions of the Navier-Stokes equations---NSE---for the ink flow and, every day common sense, must provide answers to relevant questions still pending response in the offset printing process. Among these questions are: the influence of wall pressure on the flow, the presence or lack thereof of cavitation, the influence of the Newtonian and non- Newtonian conditions of the ink and, the validity of Stefan's law in the flow as ink and substrate split from the blanket/ink interface. As those questions are properly studied and, solutions are provided on the influence of the ink flow on common substrates (mainly focused on coated papers). Answers are presented on ink velocity profiles, influence of ink viscosity and ink layer height (under full ink coverage), and adequate release of the substrate at common SFO---Sheet Fed Offset---printing conditions. In order to understand the flow, a model is proposed by using a thin channel, high aspect ratio, based on the very thin ink layer running at 2 microns (2 x 10--6 m) through a long contacting channel S, of 0.012 m, while the walls move at a set velocity of 3 m/s and known contacting pressure (peaking at the center at 1 MPa). The problem is divided in two regions with similar geometry (high aspect ratio) but, with different boundary conditions. Inside the nip, the problem is a Couette-like flow. Once it leaves the nip, the problem turns into an adhesion matter. Due the high aspect ratio, NSE can be simplified to the Lubrication Approximation Equations---LAE. The printing process is absolutely symmetric in the depth direction of the flow---considered here as y-direction in accordance with paper physics literature---, validating the simplification of the study from 3D to 2D. The physics and geometry of the flow indicate as well that: the fluid is incompressible, the interaction of the ink and substrate happen very rapidly

New aspects concerning geoelectrical tests on shallow landslides in Telega, Romania

NASA Astrophysics Data System (ADS)

Maftei, R.-M.; Rusu, E.; Ciurean, R.; Avram, O.; Scutelnicu, I.; Grigorescu, S.; Grigorescu, A.

2009-04-01

New aspects concerning geoelectrical tests on shallow landslides in Telega, Romania Raluca Maftei, Emil Rusu, Roxana Ciurean, Ovidiu Avram, Ionut Scutelnicu, Stefan Grigorescu, Andrei Grigorescu (1) (1) GIR, Bucharest, Romania The analysis of natural hazards involved by landslides requires the revealing of both depth and relief of the slipping surface, and also to show the extension of the dislocated material areas. A particular aspect in Romania is related to the frequent occurrence of salt. It is to be mentioned that Romania contains the largest salt resources/reserves throughout Europe. This potential of about three billion tons could supply salt for the whole world population for over four hundred years. Telega village, separated by Campina town through Doftana River, is situated at 5 km from it, in the west part of Prahova County. The village covers a medium altitude relief (550m), characterized by irregularities of ground, many valleys and swales crossed by streams. On the left bank of Telega valley, the landslides' effects have a large extension, in some places being catastrophic. Among these, the one called at "Butoi" area presents a huge interest according of their produced destructions and because of the influence on Telega Spa, main communal road etc. In the above-mentioned sector, the slope is badly affected over a 0.4 sqkm surface. The morphology presents many scars, sometimes with steeps, waves with variable amplitudes and counter slope aspects in which water accumulates as lakes and swamps, with transversal and longitudinal fissures with different lengths and depths. The slope is very steep, especially in crest area. Besides the covering deluvial, clayey, yellow-gray quaternary rocks, other rocks form the basement are moving, in the detachment area marly, gray-black, fine stratified, sandy rocks interbeded with soft, gray sandstones of Meotian age are affected. Also, the rocks of the "salt breccias horizon" of Badenian age are affected. Predominantly

PREFACE: Eighth International Conference on Dissociative Recombination (DR2010)

NASA Astrophysics Data System (ADS)

Guberman, Steven L.; Orel, Ann E.

2011-07-01

Lake Louise, Alberta, Canada in May, 1988 [2] and was followed in May 1992 [3] at L'Abbaye de Saint Jacut de la Mer, Brittany, France, in May, 1995 [4] at Ein Gedi, Israel, in June 1999 [5] on the island of Nässlingen in the Stockholm archipelago, Sweden, in August, 2001 [6] at Chicago, USA, in July, 2004 [7] at the Alte Mälzerei, Mosbach, Germany and in July, 2007 [8] at the Resort d'Amelander Kaap on the island of Ameland, The Netherlands. All papers from the last two conferences and this conference are freely available at http://iopscience.iop.org/1742-6596. In keeping with the tradition of prior DR conferences, all papers in this volume have been refereed. Our thanks go to the referees for their efforts. Travel support for conference participants was provided by NSF grant ATM-0838061 and NASA grant NNX09AQ73G to SLG. We thank Priscilla Kujawski for proofreading the Dedication. Steven L GubermanAnn E OrelEditors Conference photograph Participants of the 8th International Conference on Dissociative Recombination: Theory, Experiments and Applications. 1. Stephen Pratt18. Randy Vane35. Robert Continetti 2. Chris Greene19. Claude Krantz36. Henrik Buhr 3. Bastiaan Braams20. Xavier Urbain37. Mats Larsson 4. Ed Grant21. Hidekazu Takagi38. Dirk Schwalm 5. Christian Nordhorn22. Brian Mitchell39. Evelyne Roueff 6. Steen Brønsted Nielsen23. Andreas Wolf40. Pascal Pernot 7. Dermot Madden24. Daren Stotler41. Stefan Rosén 8. Radek Plašil25. Slava Kokoouline42. Rainer Johnsen 9. Daniel Savin26. David Schultz43. Xiaohong Cai 10. Jonathan Tennyson27. Mourad Telmini44. Dan Haxton 11. Peet Hickman28. Ruth Malenda45. Åsa Larson 12. Michael Fogle29. Slim Chourou46. Dahbia Talbi 13. Waffeu Tamo Francois Oliver30. Petr Dohnal47. Ann Orel 14. Christian Jungen31. Julia Stützel48. Steven Guberman 15. Ilya Fabrikant32. Ioan Schneider49. Jane Fox 16. Wolf Geppert33. Nicholas Shuman50. Richard Thomas 17. Oldřich Novotný34. Holger Kreckel51. Fangfang Ruan

Modelling the energy future of Switzerland after the phase out of nuclear power plants

NASA Astrophysics Data System (ADS)

Diaz, Paula; Van Vliet, Oscar

2015-04-01

HES [Pfenninger, 2015]. It has been specifically design to represent high shares of renewable energy, allowing for the estimation of the Swiss energy transition with high level of detail. Calliope includes topology characteristics of the electricity system, and variability of radiation and wind, which enables the analysis of intermittency in renewable electricity sources, in order to fulfil the electricity demand at all hours. Three energy scenarios are modelled; first, the higher energy production of renewables in Switzerland and the import of natural gas to supply the demand; second, imports of wind power from North Sea with high level of intermittency; and third, imports of solar power from North Africa, with less intermittency but with higher risk of internal turmoil. To summarise, we analyse in detail the energy scenarios of Switzerland when the nuclear power plants will be ceased. A gap currently present in academia, such as the future energy security in Switzerland, is covered by our Calliope modelling. References: Abt, M.; E. Bernhard, A. Kolliker, T. Roth, M. Spicher, L. Stieger, Volkswirtschaftliche Massnahmenanalyse zur Energiestrategie 2050: Tiel I: Gesamtergebnisse und Empfehlungen, Staatssekretariat fur Wirtschaft SECO, Bern, CH, 2012. Busser, M; T. Kaiser, E. Wassermann, K. Ammon, S. Reichen, A. Gunzinger, et al., Energiestrategie 2050 aus Sicht des Energie Trialogs, Energie Trialog Schweiz, 2013. Mathiesen, B. V. and Lund, H. Comparative analyses of seven technologies to facilitate the integration of fluctuating renewable energy sources. IET Renew. Power Gen. 3, 190-204 (2009). Mathys, N. 2012. Modelling contributions to the Swiss energy and environmental challenge. Special issue on energy modelling_introductory article.Swiss journal of economics and statistics. Pfenninger, Stefan. 2015. Calliope: a multi-scale energy systems (MUSES) modeling framework. Available at: http://www.callio.pe/ Piot, M. Energiestrategie 2050 der Schweiz, in: 13. Symp

Self-organization in magnetic flux ropes

NASA Astrophysics Data System (ADS)

Lukin, Vyacheslav S.

2014-06-01

This cross-disciplinary special issue on 'Self-organization in magnetic flux ropes' follows in the footsteps of another collection of manuscripts dedicated to the subject of magnetic flux ropes, a volume on 'Physics of magnetic flux ropes' published in the American Geophysical Union's Geophysical Monograph Series in 1990 [1]. Twenty-four years later, this special issue, composed of invited original contributions highlighting ongoing research on the physics of magnetic flux ropes in astrophysical, space and laboratory plasmas, can be considered an update on our state of understanding of this fundamental constituent of any magnetized plasma. Furthermore, by inviting contributions from research groups focused on the study of the origins and properties of magnetic flux ropes in a variety of different environments, we have attempted to underline both the diversity of and the commonalities among magnetic flux ropes throughout the solar system and, indeed, the universe. So, what is a magnetic flux rope? The answer will undoubtedly depend on whom you ask. A flux rope can be as narrow as a few Larmor radii and as wide as the Sun (see, e.g., the contributions by Heli Hietala et al and by Angelous Vourlidas). As described below by Ward Manchester IV et al , they can stretch from the Sun to the Earth in the form of interplanetary coronal mass ejections. Or, as in the Swarthmore Spheromak Experiment described by David Schaffner et al , they can fit into a meter-long laboratory device tended by college students. They can be helical and line-tied (see, e.g., Walter Gekelman et al or J Sears et al ), or toroidal and periodic (see, e.g., John O'Bryan et al or Philippa Browning et al ). They can form in the low plasma beta environment of the solar corona (Tibor Török et al ), the order unity beta plasmas of the solar wind (Stefan Eriksson et al ) and the plasma pressure dominated stellar convection zones (Nicholas Nelson and Mark Miesch). In this special issue, Setthivoine You

PREFACE: EMAS 2011: 12th European Workshop on Modern Developments in Microbeam Analysis

NASA Astrophysics Data System (ADS)

Brisset, François; Dugne, Olivier; Robaut, Florence; Lábár, János L.; Walker, Clive T.

2012-03-01

presentation of their work in three dedicated sessions. The prize for the best poster was an invitation to participate in the 22nd Australian Conference on Microscopy and Microanalysis (ACMM 22) at Perth, Western Australia. The prize was awarded to G Samardzija of the Jozef Stefan Institute, Ljubljana, for the poster entitled: 'EPMA-WDS quantitative compositional analysis of barium titanate ceramics doped with cerium'. This proceedings volume contains the full texts of 5 of the invited plenary lectures and of 23 papers on related topics originating from the posters presented at the workshop. All the papers have been subjected to peer review by a least two referees. January 2012 Acknowledgements On behalf of the European Microbeam Analysis Society I would like to thank all the invited speakers, session chairs and members of the discussion panels for making the meeting such a great success. Special thanks go to François Brisset and Luc Van't dack who directed the organisation of the workshop giving freely of their time and talents. As was the case for previous workshops, the EMAS board in corpore was responsible for the scientific programme. The technical exhibition, which occupied 130 sq.m of floor space, was outstanding. It was very encouraging to see new instruments on display, including a FEG electron microprobe as a first worldwide presentation. Moreover, almost all the companies that exhibited provided financial support, either by sponsoring an event or by advertising. Below, in alphabetical order, is a list of exhibiting companies and sponsors of the workshop: Ametek GmbH, Edax Business UnitGN-MEBA Bruker Nano GmbHJeol (Europe) SAS CamecaL'Oréal, Direction Générale Recherche et Innovation Carl Zeiss NTSNanoMEGAS sprl Commissariat à l'Energie AtomiqueOxford Instruments SAS European Institute for Transuranium Elements (Germany)Probe Software, Inc. ElexienceSAMx FEI CompanyTarget-Messtechnik Fondis Electronic SAThermo Fisher Scientific Gatan (France) Clive T. Walker