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1

Local non-equilibrium thermodynamics  

E-Print Network [OSTI]

Local Shannon entropy lies at the heart of modern thermodynamics, with much discussion of trajectory-dependent entropy production. When taken at both boundaries of a process in phase space, it reproduces the second law of thermodynamics over a finite time interval for small scale systems. However, given that entropy is an ensemble property, it has never been clear how one can assign such a quantity locally. Given such a fundamental omission in our knowledge, we construct a new ensemble composed of trajectories reaching an individual microstate, and show that locally defined entropy, information, and free energy are properties of the ensemble, or trajectory-independent true thermodynamic potentials. We find that the Boltzmann-Gibbs distribution and Landauer's principle can be generalized naturally as properties of the ensemble, and that trajectory-free state functions of the ensemble govern the exact mechanism of non-equilibrium relaxation.

Jinwoo, Lee

2015-01-01T23:59:59.000Z

2

Non-equilibrium many body dynamics  

SciTech Connect (OSTI)

This Riken BNL Research Center Symposium on Non-Equilibrium Many Body Physics was held on September 23-25, 1997 as part of the official opening ceremony of the Center at Brookhaven National Lab. A major objective of theoretical work at the center is to elaborate on the full spectrum of strong interaction physics based on QCD, including the physics of confinement and chiral symmetry breaking, the parton structure of hadrons and nuclei, and the phenomenology of ultra-relativistic nuclear collisions related to the up-coming experiments at RHIC. The opportunities and challenges of nuclear and particle physics in this area naturally involve aspects of the many body problem common to many other fields. The aim of this symposium was to find common theoretical threads in the area of non-equilibrium physics and modern transport theories. The program consisted of invited talks on a variety topics from the fields of atomic, condensed matter, plasma, astrophysics, cosmology, and chemistry, in addition to nuclear and particle physics. Separate abstracts have been indexed into the database for contributions to this workshop.

Creutz, M.; Gyulassy, M.

1997-09-22T23:59:59.000Z

3

Non--Equilibrium Blunt Body Flow 1 Analysis of NonEquilibrium, Hypersonic Blunt  

E-Print Network [OSTI]

Non--Equilibrium Blunt Body Flow 1 Analysis of Non­Equilibrium, Hypersonic Blunt Body Flow streamline quantities and the stagnation point heat transfer in hypersonic flows about spheres or cylinders, as two-- dimensional hypersonic flows about spheres or cylinders exhibit an approximate local similarity

4

Non-equilibrium Thermodynamics of Spacetime  

E-Print Network [OSTI]

It has previously been shown that the Einstein equation can be derived from the requirement that the Clausius relation dS = dQ/T hold for all local acceleration horizons through each spacetime point, where dS is one quarter the horizon area change in Planck units, and dQ and T are the energy flux across the horizon and Unruh temperature seen by an accelerating observer just inside the horizon. Here we show that a curvature correction to the entropy that is polynomial in the Ricci scalar requires a non-equilibrium treatment. The corresponding field equation is derived from the entropy balance relation dS =dQ/T+dS_i, where dS_i is a bulk viscosity entropy production term that we determine by imposing energy-momentum conservation. Entropy production can also be included in pure Einstein theory by allowing for shear viscosity of the horizon.

Christopher Eling; Raf Guedens; Ted Jacobson

2006-02-01T23:59:59.000Z

5

Energy-exchange stochastic models for non-equilibrium  

E-Print Network [OSTI]

Non-equilibrium steady states are subject to intense investigations but still poorly understood. For instance, the derivation of Fourier law in Hamiltonian systems is a problem that still poses several obstacles. In order to investigate non-equilibrium systems, stochastic models of energy-exchange have been introduced and they have been used to identify universal properties of non-equilibrium. In these notes, after a brief review of the problem of anomalous transport in 1-dimensional Hamiltonian systems, some boundary-driven interacting random systems are considered and the "duality approach" to their rigorous mathematical treatment is reviewed. Duality theory, of which a brief introduction is given, is a powerful technique to deal with Markov processes and interacting particle systems. The content of these notes is mainly based on the papers [10, 11, 12].

Chiara Franceschini; Cristian Giardina

2014-10-14T23:59:59.000Z

6

DSMC predictions of non-equilibrium reaction rates.  

SciTech Connect (OSTI)

A set of Direct Simulation Monte Carlo (DSMC) chemical-reaction models recently proposed by Bird and based solely on the collision energy and the vibrational energy levels of the species involved is applied to calculate nonequilibrium chemical-reaction rates for atmospheric reactions in hypersonic flows. The DSMC non-equilibrium model predictions are in good agreement with theoretical models and experimental measurements. The observed agreement provides strong evidence that modeling chemical reactions using only the collision energy and the vibrational energy levels provides an accurate method for predicting non-equilibrium chemical-reaction rates.

Gallis, Michail A.; Bond, Ryan Bomar; Torczynski, John Robert

2010-04-01T23:59:59.000Z

7

Steady quantum coherence in non-equilibrium environment  

E-Print Network [OSTI]

We study the steady state of a three-level system in contact with a non-equilibrium environment, which is composed of two independent heat baths at different temperatures. We derive a master equation to describe the non-equilibrium process of the system. For the three level systems with two dipole transitions, i.e., the $\\Lambda$-type and V-type, we find that the interferences of two transitions in a non-equilibrium environment can give rise to non-vanishing steady quantum coherence, namely, there exist non-zero off-diagonal terms in the steady state density matrix (in the energy representation). Moreover, the non-vanishing off-diagonal terms increase with the temperature difference of the two heat baths. Such interferences of the transitions were usually omitted by secular approximation, for it was usually believed that they only take effect in short time behavior and do not affect the steady state. Here we show that, in non-equilibrium systems, such omission would lead to the neglect of the steady quantum coherence.

Sheng-Wen Li; C. Y. Cai; C. P. Sun

2014-07-16T23:59:59.000Z

8

The Fluctuation and NonEquilibrium Free Energy Theorems -Theory & Experiment The Fluctuation and NonEquilibrium Free Energy Theorems  

E-Print Network [OSTI]

and NonEquilibrium Free Energy Theorems - Theory & Experiment. Denis J. Evans, Edie Sevick, Genmaio Wang, David Carberry, Emil Mittag and James Reid Research School of Chemistry, Australian National University was given by Evans, Cohen & Morriss, 1993. This statement was for isoenergetic nonequilibrium steady states

Evans, Denis

9

Non-equilibrium fission processes in intermediate energy nuclear collisions  

SciTech Connect (OSTI)

We have measured the target fragment yields, angular and energy distributions for the interaction of 12-16 MeV/A/sup 32/S with /sup 165/Ho and /sup 197/Au and for the interaction of 32 and 44 MeV/A /sup 40/Ar with /sup 197/Au. The Au fission fragments associated with the peripheral collision peak in the folding angle distribution originate in a normal, ''slow'' fission process in which statistical equilibrium has been established. At the two lowest projectile energies, the Au fission fragments associated with the central collision peak in the folding angle distribution originate in part from ''fast'' (/tau//approximately//sup /minus/23/s), non-equilibrium processes. Most of the Ho fission fragments originate in non- equilibrium processes. The fast, non-equilibrium process giving rise to these fragments has many of the characteristics of ''fast fission'', but the cross sections associated with these fragments are larger than one would expect from current theories of ''fast fission. '' 14 refs., 8 figs.

Loveland, W.; Casey, C.; Xu, Z.; Seaborg, G.T.; Aleklett, K.; Sihver, L.

1989-04-01T23:59:59.000Z

10

Non-equilibrium thermodynamics of damped Timoshenko and damped Bresse systems  

E-Print Network [OSTI]

In this paper, we cast damped Timoshenko and damped Bresse systems into a general framework for non-equilibrium thermodynamics, namely the GENERIC (General Equation for Non-Equilibrium Reversible-Irreversible Coupling) framework.

Manh Hong Duong

2014-11-28T23:59:59.000Z

11

Ethanol reforming in non-equilibrium plasma of glow discharge  

E-Print Network [OSTI]

The results of a detailed kinetic study of the main plasma chemical processes in non-equilibrium ethanol/argon plasma are presented. It is shown that at the beginning of the discharge the molecular hydrogen is mainly generated in the reaction of ethanol H-abstraction. Later hydrogen is formed from active H, CH2OH and CH3CHOH and formaldehyde. Comparison with experimental data has shown that the used kinetic mechanism predicts well the concentrations of main species at the reactor outlet.

Levko, D

2012-01-01T23:59:59.000Z

12

Non-equilibrium electromagnetic fluctuations: Heat transfer and interactions  

E-Print Network [OSTI]

The Casimir force between arbitrary objects in equilibrium is related to scattering from individual bodies. We extend this approach to heat transfer and Casimir forces in non-equilibrium cases where each body, and the environment, is at a different temperature. The formalism tracks the radiation from each body and its scatterings by the other objects. We discuss the radiation from a cylinder, emphasizing its polarized nature, and obtain the heat transfer between a sphere and a plate, demonstrating the validity of proximity transfer approximation at close separations and arbitrary temperatures.

Matthias Krüger; Thorsten Emig; Mehran Kardar

2011-02-18T23:59:59.000Z

13

Non-Equilibrium Conformal Field Theories with Impurities  

E-Print Network [OSTI]

We present a construction of non-equilibrium steady states within conformal field theory. These states sustain energy flows between two quantum systems, initially prepared at different temperatures, whose dynamical properties are represented by two, possibly different, conformal field theories connected through an impurity. This construction relies on a real time formulation of conformal defect dynamics based on a field scattering picture parallelizing - but yet different from - the Euclidean formulation. We present the basic characteristics of this formulation and give an algebraic construction of the real time scattering maps that we illustrate in the case of SU(2)-based conformal field theories.

D. Bernard; B. Doyon; J. Viti

2015-01-20T23:59:59.000Z

14

Non-equilibrium Statistical Approach to Friction Models  

E-Print Network [OSTI]

A geometric approach to the friction phenomena is presented. It is based on the holographic view which has recently been popular in the theoretical physics community. We see the system in one-dimension-higher space. The heat-producing phenomena are most widely treated by using the non-equilibrium statistical physics. We take 2 models of the earthquake. The dissipative systems are here formulated from the geometric standpoint. The statistical fluctuation is taken into account by using the (generalized) Feynman's path-integral.

Shoichi Ichinose

2014-04-26T23:59:59.000Z

15

Non-equilibrium magnetic interactions in strongly correlated systems  

SciTech Connect (OSTI)

We formulate a low-energy theory for the magnetic interactions between electrons in the multi-band Hubbard model under non-equilibrium conditions determined by an external time-dependent electric field which simulates laser-induced spin dynamics. We derive expressions for dynamical exchange parameters in terms of non-equilibrium electronic Green functions and self-energies, which can be computed, e.g., with the methods of time-dependent dynamical mean-field theory. Moreover, we find that a correct description of the system requires, in addition to exchange, a new kind of magnetic interaction, that we name twist exchange, which formally resembles Dzyaloshinskii–Moriya coupling, but is not due to spin–orbit, and is actually due to an effective three-spin interaction. Our theory allows the evaluation of the related time-dependent parameters as well. -- Highlights: •We develop a theory for magnetism of strongly correlated systems out of equilibrium. •Our theory is suitable for laser-induced ultrafast magnetization dynamics. •We write time-dependent exchange parameters in terms of electronic Green functions. •We find a new magnetic interaction, a “twist exchange”. •We give general expressions for magnetic noise in itinerant-electron systems.

Secchi, A., E-mail: a.secchi@science.ru.nl [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands); Brener, S.; Lichtenstein, A.I. [Institut für Theoretische Physik, Universitat Hamburg, Jungiusstraße 9, D-20355 Hamburg (Germany)] [Institut für Theoretische Physik, Universitat Hamburg, Jungiusstraße 9, D-20355 Hamburg (Germany); Katsnelson, M.I. [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands)] [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands)

2013-06-15T23:59:59.000Z

16

Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow computations  

E-Print Network [OSTI]

Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow. For the non-equilibrium flow computations, i.e., the nozzle flow and hypersonic rarefied flow over flat plate-kinetic method; Hypersonic and rarefied flows 1. Introduction The development of aerospace technology has

Xu, Kun

17

Strongly interacting Fermi gases : non-equilibrium dynamics and dimensional crossover  

E-Print Network [OSTI]

Experiments using ultracold atomic gases address fundamental problems in many-body physics. This thesis describes experiments on strongly-interacting gases of fermionic atoms, with a focus on non-equilibrium physics and ...

Sommer, Ariel T. (Ariel Tjodolv)

2013-01-01T23:59:59.000Z

18

PHYSICS OF FLUIDS 26, 052001 (2014) Capturing non-equilibrium phenomena in rarefied  

E-Print Network [OSTI]

PHYSICS OF FLUIDS 26, 052001 (2014) Capturing non-equilibrium phenomena in rarefied polyatomic: 142.104.86.60 On: Mon, 05 May 2014 20:27:14 #12;052001-2 B. Rahimi and H. Struchtrup Phys. Fluids 26

Struchtrup, Henning

19

The Application of Dynamic Nuclear Polarization Enhanced NMR to Non-Equilibrium Systems  

E-Print Network [OSTI]

Nuclear magnetic resonance (NMR) yields remarkably detailed structural information about virtually any molecule. However, its application to non-equilibrium systems is hampered by a lack of sensitivity. To increase the amount of signal that can...

Bowen, Sean Michael

2012-02-14T23:59:59.000Z

20

Influence of Penning effect on the plasma features in a non-equilibrium atmospheric pressure plasma jet  

E-Print Network [OSTI]

Influence of Penning effect on the plasma features in a non-equilibrium atmospheric pressure plasma 2014 23:18:06 #12;Influence of Penning effect on the plasma features in a non-equilibrium atmospheric March 2014) Non-equilibrium atmospheric pressure plasma jet (APPJ) is a cold plasma source that promises

Zexian, Cao

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Note: Local thermal conductivities from boundary driven non-equilibrium molecular dynamics simulations  

SciTech Connect (OSTI)

We report non-equilibrium molecular dynamics simulations of heat transport in models of molecular fluids. We show that the “local” thermal conductivities obtained from non-equilibrium molecular dynamics simulations agree within numerical accuracy with equilibrium Green-Kubo computations. Our results support the local equilibrium hypothesis for transport properties. We show how to use the local dependence of the thermal gradients to quantify the thermal conductivity of molecular fluids for a wide range of thermodynamic states using a single simulation.

Bresme, F., E-mail: f.bresme@imperial.ac.uk [Department of Chemistry, Chemical Physics Section, Imperial College London, London SW7 2AZ (United Kingdom); Department of Chemistry, Norwegian University of Science and Technology, Trondheim (Norway); Armstrong, J., E-mail: j.armstrong@imperial.ac.uk [Department of Chemistry, Chemical Physics Section, Imperial College London, London SW7 2AZ (United Kingdom)

2014-01-07T23:59:59.000Z

22

Modeling a Proton Exchange Membrane Fuel Cell using Non-Equilibrium Thermodynamics: A Second Law analysis of assumptions and parameters:.  

E-Print Network [OSTI]

??In this work, a model derived from Non-Equilibrium Thermodynamics, for the Proton Exchange Membrane Fuel Cell, was utilized in order to explore the effect of… (more)

Garcia Navarro, J.C.

2014-01-01T23:59:59.000Z

23

Thermal recovery from a fractured medium in local thermal non-equilibrium Rachel Geleta,b,  

E-Print Network [OSTI]

effective stress is tensile near the injection well, illustrating the thermal contraction of the rock, whileThermal recovery from a fractured medium in local thermal non-equilibrium Rachel Geleta, Australia Abstract Thermal recovery from a hot dry rock reservoir viewed as a deformable fractured medium

Paris-Sud XI, Université de

24

Transient Analysis of Data Traffic in Cognitive Radio Networks: A Non-equilibrium Statistical  

E-Print Network [OSTI]

efficiency of spectrum utilization. In cognitive radio systems, a secondary user (without license) can access a licensed spectrum channel if there is no primary user (with license) transmitting over this channel. When1 Transient Analysis of Data Traffic in Cognitive Radio Networks: A Non-equilibrium Statistical

Li, Husheng

25

Small angle neutron scattering (SANS) under non-equilibrium conditions R. C. Oberthr  

E-Print Network [OSTI]

663 Small angle neutron scattering (SANS) under non-equilibrium conditions R. C. Oberthür Institut with the times obtained from quasi- elastic neutron and light scattering, which yield information about neutrons aux petits angles (DNPA) pour l'étude des systèmes hors d'équi- libre thermodynamique est

Boyer, Edmond

26

Non-equilibrium phase transition in mesoscopic biochemical systems: from stochastic to nonlinear dynamics and beyond  

Science Journals Connector (OSTI)

...challenging questions in biological physics is whether non-equilibrium...not smooth itself. So one does not have a phi(x). For...1983 Stochastic processes in physics and chemistry. Amsterdam...54 Gardiner, C. W. 1985 Handbook of stochastic methods. Berlin...

2011-01-01T23:59:59.000Z

27

Kinetic effects of non-equilibrium plasma-assisted methane oxidation on diffusion flame extinction limits  

E-Print Network [OSTI]

. The prod- ucts of plasma assisted CH4 oxidation were measured using the Two-photon Absorption Laser to understand the role of plasma generated species on ignition, flame speed, and flame stabilization. For ignition studies, the reduction of ignition delay time by non-equilibrium nanosecond pulsed discharges

Ju, Yiguang

28

Experimental Analysis of the Effect of Vibrational Non-Equilibrium on the Decay of Grid-Generated Turbulence  

E-Print Network [OSTI]

the fundamental scientific question: ?Does thermal non-equilibrium alter the decay rate of turbulence?? The results of this study show that the answer is ?Yes.? The results demonstrate a clear coupling between thermal non-equilibrium and turbulence transport... ................................................................... 86 2.70 Macor-aluminum test section (exploded view) ....................................... 87 2.71 Upwind flange .......................................................................................... 88 2.72 Macor slab...

Fuller, T. J.

2010-10-12T23:59:59.000Z

29

Heating of thermal non-equilibrium ions by Alfvén wave via nonresonant interaction  

SciTech Connect (OSTI)

Pickup of thermal non-equilibrium ions by Alfvén wave via nonresonant wave-particle interaction is investigated by means of analytical test-particle theory. Some interesting and new results are found. No matter what the initial velocity distribution is, if the background magnetic field, the Alfvén speed, and the Alfvén magnetic field are fixed, the average parallel velocity never changes when t??. Heating effects in the perpendicular and parallel direction just depend on the initial temperature, and the perpendicular temperature increase is more prominent. It is noted that the heating effect of thermal non-equilibrium ions (Kappa ions) is weaker than that of the Maxwellian. This phenomenon may be relative to the heating of ions in the solar corona as well as in some toroidal confinement fusion devices.

Liu, Hai-Feng; Wang, Shi-Qing [Southwestern Institute of Physics, Chengdu 610041 (China) [Southwestern Institute of Physics, Chengdu 610041 (China); The Engineering and Technical College of Chengdu University of Technology, Leshan 614000 (China); Li, Ke-Hua [The Engineering and Technical College of Chengdu University of Technology, Leshan 614000 (China)] [The Engineering and Technical College of Chengdu University of Technology, Leshan 614000 (China)

2013-10-15T23:59:59.000Z

30

Strongly anisotropic non-equilibrium phase transition in Ising models with friction  

E-Print Network [OSTI]

The non-equilibrium phase transition in driven two-dimensional Ising models with two different geometries is investigated using Monte Carlo methods as well as analytical calculations. The models show dissipation through fluctuation induced friction near the critical point. We first consider high driving velocities and demonstrate that both systems are in the same universality class and undergo a strongly anisotropic non-equilibrium phase transition, with anisotropy exponent \\theta=3. Within a field theoretical ansatz the simulation results are confirmed. The crossover from Ising to mean field behavior in dependency of system size and driving velocity is analyzed using crossover scaling. It turns out that for all finite velocities the phase transition becomes strongly anisotropic in the thermodynamic limit.

Sebastian Angst; Alfred Hucht; Dietrich E. Wolf

2012-01-10T23:59:59.000Z

31

Non-equilibrium phase transition in an exactly solvable driven Ising model with friction  

E-Print Network [OSTI]

A driven Ising model with friction due to magnetic correlations has recently been proposed by Kadau et al. (Phys. Rev. Lett. 101, 137205 (2008)). The non-equilibrium phase transition present in this system is investigated in detail using analytical methods as well as Monte Carlo simulations. In the limit of high driving velocities $v$ the model shows mean field behavior due to dimensional reduction and can be solved exactly for various geometries. The simulations are performed with three different single spin flip rates: the common Metropolis and Glauber rates as well as a multiplicative rate. Due to the non-equilibrium nature of the model all rates lead to different critical temperatures at $v>0$, while the exact solution matches the multiplicative rate. Finally, the cross-over from Ising to mean field behavior as function of velocity and system size is analysed in one and two dimensions.

Alfred Hucht

2009-09-02T23:59:59.000Z

32

Non-equilibrium thermodynamics of dark energy on the power-law entropy corrected apparent horizon  

E-Print Network [OSTI]

We investigate the Friedmann-Robertson-Walker (FRW) universe (containing dark energy) as a non-equilibrium (irreversible) thermodynamical system by considering the power-law correction to the horizon entropy. By taking power-law entropy area law which appear in dealing with the entanglement of quantum fields in and out the horizon, we determine the power-law entropy corrected apparent horizon of the FRW universe.

M. Umar Farooq; Mubasher Jamil

2011-11-24T23:59:59.000Z

33

Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification  

SciTech Connect (OSTI)

The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point selection, however, requires a model for solute partitioning under a given set of growth conditions. Therefore, analytical solute trapping models which describe the chemical partitioning as a function of steady state interface velocities have been developed and widely utilized in most of the theoretical investigations of rapid solidification. However, these solute trapping models are not rigorously verified due to the difficulty in experimentally measuring under rapid growth conditions. Moreover, since these solute trapping models include kinetic parameters which are difficult to directly measure from experiments, application of the solute trapping models or the associated analytic rapid solidification model is limited. These theoretical models for steady state rapid solidification which incorporate the solute trapping models do not describe the interdependency of solute diffusion, interface kinetics, and alloy thermodynamics. The phase-field approach allows calculating, spontaneously, the non-equilibrium growth effects of alloys and the associated time-dependent growth dynamics, without making the assumptions that solute partitioning is an explicit function of velocity, as is the current convention. In the research described here, by utilizing the phase-field model in the thin-interface limit, incorporating the anti-trapping current term, more quantitatively valid interface kinetics and solute diffusion across the interface are calculated. In order to sufficiently resolve the physical length scales (i.e. interface thickness and diffusion boundary length), grid spacings are continually adjusted in calculations. The full trajectories of transient planar growth dynamics under rapid directional solidification conditions with different pulling velocities are described. As a validation of a model, the predicted steady state conditions are consistent with the analytic approach for rapid growth. It was confirmed that rapid interface dynamics exhibits the abrupt acceleration of the planar front when the effect of the non-equilibrium solute partitioning at the interface becomes signi ficant. This is consistent with the previous linear stability analysis for the non-equilibrium interface dynamics. With an appropriate growth condition, the continuous oscillation dynamics was able to be simulated using continually adjusting grid spacings. This oscillatory dynamics including instantaneous jump of interface velocities are consistent

Choi, Jeong

2011-08-15T23:59:59.000Z

34

NON-EQUILIBRIUM IONIZATION MODELING OF THE CURRENT SHEET IN A SIMULATED SOLAR ERUPTION  

SciTech Connect (OSTI)

The current sheet that extends from the top of flare loops and connects to an associated flux rope is a common structure in models of coronal mass ejections (CMEs). To understand the observational properties of CME current sheets, we generated predictions from a flare/CME model to be compared with observations. We use a simulation of a large-scale CME current sheet previously reported by Reeves et al. This simulation includes ohmic and coronal heating, thermal conduction, and radiative cooling in the energy equation. Using the results of this simulation, we perform time-dependent ionization calculations of the flow in a CME current sheet and construct two-dimensional spatial distributions of ionic charge states for multiple chemical elements. We use the filter responses from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory and the predicted intensities of emission lines to compute the count rates for each of the AIA bands. The results show differences in the emission line intensities between equilibrium and non-equilibrium ionization. The current sheet plasma is underionized at low heights and overionized at large heights. At low heights in the current sheet, the intensities of the AIA 94 A and 131 A channels are lower for non-equilibrium ionization than for equilibrium ionization. At large heights, these intensities are higher for non-equilibrium ionization than for equilibrium ionization inside the current sheet. The assumption of ionization equilibrium would lead to a significant underestimate of the temperature low in the current sheet and overestimate at larger heights. We also calculate the intensities of ultraviolet lines and predict emission features to be compared with events from the Ultraviolet Coronagraph Spectrometer on the Solar and Heliospheric Observatory, including a low-intensity region around the current sheet corresponding to this model.

Shen Chengcai; Reeves, Katharine K.; Raymond, John C.; Murphy, Nicholas A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ko, Yuan-Kuen [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Lin Jun [Yunnan Astronomical Observatory, Chinese Academy of Sciences, P. O. Box 110, Kunming, Yunnan 650011 (China); Mikic, Zoran; Linker, Jon A. [Predictive Science, Inc. (PSI), San Diego, CA 92121-2910 (United States)

2013-08-20T23:59:59.000Z

35

Fundamental Properties of Non-equilibrium Laser-Supported Detonation Wave  

SciTech Connect (OSTI)

For developing laser propulsion, it is very important to analyze the mechanism of Laser-Supported Detonation (LSD), because it can generate high pressure and high temperature to be used by laser propulsion can be categorized as one type of hypersonic reacting flows, where exothermicity is supplied not by chemical reaction but by radiation absorption. I have numerically simulated the 1-D and Quasi-1-D LSD waves propagating through an inert gas, which absorbs CO2 gasdynamic laser, using a 2-temperature model. Calculated results show the fundamental properties of the non-equilibrium LSD Waves.

Shiraishi, Hiroyuki [Department of Mechanical Engineering, Daido Institute of Technology, 10-3 Taki-haru-cho, Minami-ku, Nagoya (Japan)

2004-03-30T23:59:59.000Z

36

THERMAL NON-EQUILIBRIUM REVISITED: A HEATING MODEL FOR CORONAL LOOPS  

SciTech Connect (OSTI)

The location and frequency of events that heat the million-degree corona are still a matter of debate. One potential heating scenario is that the energy release is effectively steady and highly localized at the footpoints of coronal structures. Such an energy deposition drives thermal non-equilibrium solutions in the hydrodynamic equations in longer loops. This heating scenario was considered and discarded by Klimchuk et al. on the basis of their one-dimensional simulations as incapable of reproducing observational characteristics of loops. In this paper, we use three-dimensional simulations to generate synthetic emission images, from which we select and analyze six loops. The main differences between our model and that of Klimchuk et al. concern (1) dimensionality, (2) resolution, (3) geometrical properties of the loops, (4) heating function, and (5) radiative function. We find evidence, in this small set of simulated loops, that the evolution of the light curves, the variation of temperature along the loops, the density profile, and the absence of small-scale structures are compatible with the characteristics of observed loops. We conclude that quasi-steady footpoint heating that drives thermal non-equilibrium solutions cannot yet be ruled out as a viable heating scenario for EUV loops.

Lionello, Roberto; Linker, Jon A.; Mikic, Zoran [Predictive Science, Inc., 9990 Mesa Rim Rd., Ste. 170, San Diego, CA 92121-2910 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Mok, Yung, E-mail: lionel@predsci.com, E-mail: linkerj@predsci.com, E-mail: mikicz@predsci.com, E-mail: amy.r.winebarger@nasa.gov, E-mail: ymok@uci.edu [Department of Physics and Astronomy, University of California, 4129 Reines Hall, Irvine, CA 92697 (United States)

2013-08-20T23:59:59.000Z

37

Heavy-ion collisions with non-equilibrium Dirac-Brueckner mean fields  

Science Journals Connector (OSTI)

The influence of realistic interactions on the reaction dynamics in intermediate energy heavy-ion collisions is investigated. The mean field in relativistic transport calculations is derived from microscopic Dirac-Brueckner (DB) self-energies, taking non-equilibrium effects, in particular the anisotropy of the local phase space configurations, into account. Thus this approach goes beyond the local density approximation. A detailed analysis of various in-plane and out-of-plane flow observables is presented for Au on Au reactions at incident energies ranging from 250 to 800 A MeV and the results are compared to recent measurements of the FOPI Collaboration. An overall good agreement with in-plane flow data and a reasonable description of the out-of-plane emission is achieved. For these results the intrinsic momentum dependence of the non-equilibrium mean fields is important. On the other hand, the local density approximation with the same underlying DB forces as well as a standard non-linear version of the ?? model are less successful in describing the present data. This gives evidence of the applicability of self-energies derived from the DB approach to nuclear matter also far from saturation and equilibrium.

T. Gaitanos; C. Fuchs; H.H. Wolter

1999-01-01T23:59:59.000Z

38

A definition of thermodynamic entropy valid for non-equilibrium states and few-particle systems  

E-Print Network [OSTI]

From a new rigorous formulation of the general axiomatic foundations of thermodynamics we derive an operational definition of entropy that responds to the emergent need in many technological frameworks to understand and deploy thermodynamic entropy well beyond the traditional realm of equilibrium states of macroscopic systems. The new definition is achieved by avoiding to resort to the traditional concepts of "heat" (which restricts $a$ $priori$ the traditional definitions of entropy to the equilibrium domain) and of "thermal reservoir" (which restricts $in$ $practice$ our previous definitions of non-equilibrium entropy to the many-particle domain). The measurement procedure that defines entropy is free from intrinsic limitations and can be applied, $in$ $principle$, even to non-equilibrium states of few-particle systems, provided they are separable and uncorrelated. The construction starts from a previously developed set of carefully worded operational definitions for all the basic concepts. Then, through a new set of fully spelled-out fundamental hypotheses (four postulates and five assumptions) we derive the definitions of energy and entropy of any state, and of temperature of any stable equilibrium state. Finally, we prove the principle of entropy non-decrease, the additivity of entropy differences, the maximum entropy principle, and the impossibility of existence of a thermal reservoir.

Gian Paolo Beretta; Enzo Zanchini

2014-11-19T23:59:59.000Z

39

Driving kinetically constrained models into non-equilibrium steady states: structural and slow transport properties  

E-Print Network [OSTI]

Complex fluids in shear flow and biased dynamics in crowded environments exhibit counterintuitive features which are difficult to address both at theoretical level and by molecular dynamic simulations. To understand some of these features we study a schematic model of highly viscous liquid, the 2D Kob-Andersen kinetically constrained model, driven into non-equilibrium steady states by a uniform non-Hamiltonian force. We present a detailed numerical analysis of the microscopic behavior of the model, including transversal and longitudinal spatial correlations and dynamic heterogeneities. In particular, we show that at high particle density the transition from positive to negative resistance regimes in the current vs field relation can be explained via the emergence of nontrivial structures that intermittently trap the particles and slow down the dynamics. We relate such spatial structures to the current vs field relation in the different transport regimes.

Francesco Turci; Estelle Pitard; Mauro Sellitto

2012-06-27T23:59:59.000Z

40

Expect the unexpected: non-equilibrium processes in brown dwarf atmospheres  

E-Print Network [OSTI]

Brown Dwarf atmosphere are a chemically extremely rich, one example being the formation of clouds driven by the phase-non-equilibrium of the atmospheric gas. Cloud formation modelling is an integral part of any atmosphere simulation used to interpret spectral observations of ultra-cool objects and to determine fundamental parameters like log(g) and Teff. This proceeding to the workshop 'GAIA and the Unseen: The Brown Dwarf Question' first summarizes what a model atmosphere simulation is, and then advocates two ideas: A) The use of a multitude of model families to determine fundamental parameters with realistic confidence interval. B) To keep an eye on the unexpected, like for example, ionisation signatures resulting plasma processes

Helling, Christiane

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Non-Equilibrium Superconductivity in Kinetic Inductance Detectors for THz Photon Sensing  

E-Print Network [OSTI]

Low temperature Kinetic Inductance Detectors (KIDs) are attractive candidates for producing quantumsensitive, arrayable sensors for astrophysical and other precision measurement applications. The readout uses a low frequency probe signal with quanta of energy well-below the threshold for pair-breaking in the superconductor. We have calculated the detailed non-equilibrium quasiparticle and phonon energy spectra generated by the probe signal of the KID when operating well-below its superconducting transition temperature Tc within the framework of the coupled kinetic equations described by Chang and Scalapino.[1] At the lowest bath temperature studied Tb/Tc = 0.1 the quasiparticle distributions can be driven far from equilibrium. In addition to the low frequency probe signal we have incorporated a high frequency (~ 1 THz) source signal well-above the pair-breaking threshold of the superconductor. Calculations of source signal detection efficiency are discussed

Goldie, D J

2014-01-01T23:59:59.000Z

42

Exponential approach to, and properties of, a non-equilibrium steady state in a dilute gas  

E-Print Network [OSTI]

We investigate a kinetic model of a system in contact with several thermal reservoirs at different temperatures $T_\\alpha$. Our system is a spatially uniform dilute gas whose internal dynamics is described by the nonlinear Boltzmann equation with Maxwellian collisions. Similarly, the interaction with reservoir $\\alpha$ is represented by a Markovian process that has the Maxwellian $M_{T_\\alpha}$ as its stationary state. We prove existence and uniqueness of a non-equilibrium steady state (NESS) and show exponential convergence to this NESS in a metric on probability measures introduced into the study of Maxwellian collisions by Gabetta, Toscani and Wenberg (GTW). This shows that the GTW distance between the current velocity distribution to the steady-state velocity distribution is a Lyapunov functional for the system. We also derive expressions for the entropy production in the system plus the reservoirs which is always positive.

Eric A. Carlen; Joel L. Lebowitz; Clement Mouhot

2014-06-16T23:59:59.000Z

43

Interacting dark fluid in the universe bounded by event horizon : A non-equilibrium prescription  

E-Print Network [OSTI]

A non-equilibrium thermodynamic analysis has been done for the interacting dark fluid in the universe bounded by the event horizon.From observational evidences it is assumed that at present the matter in the universe is dominated by two dark sectors-dark matter and dark energy. The mutual interaction among them results in spontaneous heat flow between the horizon and the fluid system and the thermal equilibrium will no longer hold.In the present work,the dark matter is chosen in the form of dust while the dark energy is chosen as a perfect fluid with constant equation in one case and holographic dark energy model is chosen in the other.Finally,validity of the generalized second law of thermodynamics has been examined in both cases.

Subenoy Chakraborty; Atreyee Biswas

2014-06-27T23:59:59.000Z

44

NON-EQUILIBRIUM THERMODYNAMIC PROCESSES: SPACE PLASMAS AND THE INNER HELIOSHEATH  

SciTech Connect (OSTI)

Recently, empirical kappa distribution, commonly used to describe non-equilibrium systems like space plasmas, has been connected with non-extensive statistical mechanics. Here we show how a consistent definition of the temperature and pressure is developed for stationary states out of thermal equilibrium, so that the familiar ideal gas state equation still holds. In addition to the classical triplet of temperature, pressure, and density, this generalization requires the kappa index as a fourth independent thermodynamic variable that characterizes the non-equilibrium stationary states. All four of these thermodynamic variables have key roles in describing the governing thermodynamical processes and transitions in space plasmas. We introduce a novel characterization of isothermal and isobaric processes that describe a system's transition into different stationary states by varying the kappa index. In addition, we show how the variation of temperature or/and pressure can occur through an 'iso-q' process, in which the system remains in a fixed stationary state (fixed kappa index). These processes have been detected in the proton plasma in the inner heliosheath via specialized data analysis of energetic neutral atom (ENA) observations from Interstellar Boundary Explorer. In particular, we find that the temperature is highly correlated with (1) kappa, asymptotically related to isothermal ({approx}1,000,000 K) and iso-q ({kappa} {approx} 1.7) processes; and (2) density, related to an isobaric process, which separates the 'Ribbon', P Almost-Equal-To 3.2 pdyn cm{sup -2}, from the globally distributed ENA flux, P Almost-Equal-To 2 pdyn cm{sup -2}.

Livadiotis, G.; McComas, D. J., E-mail: glivadiotis@swri.edu [Southwest Research Institute, San Antonio, TX (United States)

2012-04-10T23:59:59.000Z

45

Effect of dielectric barrier discharge plasma actuators on non-equilibrium hypersonic Ankush Bhatia, Subrata Roy, and Ryan Gosse  

E-Print Network [OSTI]

Effect of dielectric barrier discharge plasma actuators on non-equilibrium hypersonic flows Ankush-equilibrium hypersonic flows Ankush Bhatia,1 Subrata Roy,1 and Ryan Gosse2 1 Applied Physics Research Group, Department for a cylindrical body in Mach 17 hypersonic flow is presented. This application focuses on using sinusoidal

Roy, Subrata

46

2-D Hypersonic Non-equilibrium Flow Simulation using r-p Adaptive Time-Implicit Discontinuous Galerkin Method  

E-Print Network [OSTI]

2-D Hypersonic Non-equilibrium Flow Simulation using r-p Adaptive Time-Implicit Discontinuous Aerospace Sciences Meeting #12;1 American Institute of Aeronautics and Astronautics 2-D Hypersonic Non Galerkin (DG) methods to 2-D hypersonic flow problems. Previous applications of DG method were limited

Roy, Subrata

47

Many-body current formula and current conservation for non-equilibrium fully interacting nanojunctions  

Science Journals Connector (OSTI)

We consider the electron transport properties through fully interacting nanoscale junctions beyond the linear-response regime. We calculate the current flowing through an interacting region connected to two interacting leads, with interaction crossing at the left and right contacts, by using a non-equilibrium Green function technique. The total current at one interface (the left one for example) is made of several terms which can be regrouped into two sets. The first set corresponds to a very generalized Landauer-like current formula with physical quantities defined only in the interacting central region and with renormalized lead self-energies. The second set characterizes inelastic scattering events occurring in the left lead. We show how this term can be negligible or even vanish due to the pseudo-equilibrium statistical properties of the lead in the thermodynamic limit. The expressions for the different Green functions needed for practical calculations of the current are also provided. We determine the constraints imposed by the physical condition of current conservation. The corresponding equation imposed on the different self-energy quantities arising from the current conservation is derived. We discuss in detail its physical interpretation and its relation with previously derived expressions. Finally several important key features are discussed in relation to the implementation of our formalism for calculations of quantum transport in realistic systems.

H Ness; L K Dash

2012-01-01T23:59:59.000Z

48

Cosmological QCD phase transition in steady non-equilibrium dissipative Ho?ava-Lifshitz early universe  

E-Print Network [OSTI]

We study the phase transition from quark-gluon plasma to hadrons in the early universe in the context of non-equilibrium thermodynamics. According to the standard model of cosmology, a phase transition associated with chiral symmetry breaking after the electro-weak transition has occurred when the universe was about $1-10\\mu s$ old. We focus attention on such a phase transition in the presence of a viscous relativistic cosmological background fluid in the framework of non-detailed balance Ho\\v{r}ava-Lifshitz cosmology within an effective model of QCD. We consider a flat Friedmann-Robertson-Walker Universe filled with a non-causal and causal bulk viscous cosmological fluid respectively and investigate the effects of the running coupling constants of Ho\\v{r}ava-Lifshitz gravity, $\\lambda$, on the evolution of the physical quantities relevant to a description of the early universe, namely, the temperature $T$, scale factor $a$, deceleration parameter $q$ and dimensionless ratio of the bulk viscosity coefficient to entropy density $\\frac{\\xi}{s}$. We assume that the bulk viscosity cosmological background fluid obeys the evolution equation of the steady truncated (Eckart) and full version of the Israel-Stewart fluid, respectively.

M. Khodadi; H. R. Sepangi

2014-05-20T23:59:59.000Z

49

A numerical model of non-equilibrium thermal plasmas. I. Transport properties  

SciTech Connect (OSTI)

A self-consistent and complete numerical model for investigating the fundamental processes in a non-equilibrium thermal plasma system consists of the governing equations and the corresponding physical properties of the plasmas. In this paper, a new kinetic theory of the transport properties of two-temperature (2-T) plasmas, based on the solution of the Boltzmann equation using a modified Chapman-Enskog method, is presented. This work is motivated by the large discrepancies between the theories for the calculation of the transport properties of 2-T plasmas proposed by different authors in previous publications. In the present paper, the coupling between electrons and heavy species is taken into account, but reasonable simplifications are adopted, based on the physical fact that m{sub e}/m{sub h} Much-Less-Than 1, where m{sub e} and m{sub h} are, respectively, the masses of electrons and heavy species. A new set of formulas for the transport coefficients of 2-T plasmas is obtained. The new theory has important physical and practical advantages over previous approaches. In particular, the diffusion coefficients are complete and satisfy the mass conversation law due to the consideration of the coupling between electrons and heavy species. Moreover, this essential requirement is satisfied without increasing the complexity of the transport coefficient formulas. Expressions for the 2-T combined diffusion coefficients are obtained. The expressions for the transport coefficients can be reduced to the corresponding well-established expressions for plasmas in local thermodynamic equilibrium for the case in which the electron and heavy-species temperatures are equal.

Zhang XiaoNing; Xia WeiDong [Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026 (China); Li HePing [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Murphy, Anthony B. [CSIRO Materials Science and Engineering, PO Box 218, Lindfield NSW 2070 (Australia)

2013-03-15T23:59:59.000Z

50

General Expressions for Ellipsoidal-Valley Quantum Transport in Arbitrary Growth Direction: Non-Equilibrium Green's Function  

Science Journals Connector (OSTI)

A theoretical method for the calculation of quantum transport in an ellipsoidal valley is presented. This method is developed using a non-equilibrium Green's function framework. Importantly, it is instructive that kz is separated into two parts so that the wrong figure shape of the transmission coefficients does not exist. The L-electron effect on AlAs–GaAs–AlAs double barrier structures oriented in the [001], [111], and [110] growth directions is explored using the proposed method.

Chun-Nan Chen; Wei-Long Su; Meng-En Lee; Jen-Yi Jen; Yiming Li

2011-01-01T23:59:59.000Z

51

Influence of Penning effect on the plasma features in a non-equilibrium atmospheric pressure plasma jet  

SciTech Connect (OSTI)

Non-equilibrium atmospheric pressure plasma jet (APPJ) is a cold plasma source that promises various innovative applications. The influence of Penning effect on the formation, propagation, and other physical properties of the plasma bullets in APPJ remains a debatable topic. By using a 10?cm wide active electrode and a frequency of applied voltage down to 0.5?Hz, the Penning effect caused by preceding discharges can be excluded. It was found that the Penning effect originating in a preceding discharge helps build a conductive channel in the gas flow and provide seed electrons, thus the discharge can be maintained at a low voltage which in turn leads to a smaller propagation speed for the plasma bullet. Photographs from an intensified charge coupled device reveal that the annular structure of the plasma plume for He is irrelevant to the Penning ionization process arising from preceding discharges. By adding NH{sub 3} into Ar to introduce Penning effect, the originally filamentous discharge of Ar can display a rather extensive plasma plume in ambient as He. These results are helpful for the understanding of the behaviors of non-equilibrium APPJs generated under distinct conditions and for the design of plasma jet features, especially the spatial distribution and propagation speed, which are essential for application.

Chang, Zhengshi; Zhang, Guanjun [School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049 (China); Jiang, Nan; Cao, Zexian, E-mail: zxcao@iphy.ac.cn [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-03-14T23:59:59.000Z

52

Non-equilibrium dynamics of an ultracold Bose gas under a multi-pulsed quantum quench in interaction  

E-Print Network [OSTI]

We investigate the nonequilibrium dynamical properties of a weakly-interacting Bose gas at zero temperature under the multi-pulsed quantum quench in interaction by calculating one-body, two-body correlation functions and Tan's contact of the model system. The multi-pulsed quench is represented as follows: first suddenly quenching the interatomic interaction from $g_{i}$ to $g_{f}$ at time $t=0$, holding time $t$, and then suddenly quenching interaction from $g_{f}$ back to $g_{i}$, holding the time $t$ sequence $n$ times. In particular, two typical kinds of quenching parameters are chosen, corresponding to $(g_{i}/g_{f}>1)$ and $(g_{i}/g_{f}powerful way of studying the non-equilibrium dynamics of many-body quantum system than the `one-off' quantum quench. Finally, we discuss the ultra-short-range properties of the two-body correlation function after the $n$th quenching, which can be used to probe the `Tan'scontact' in experiments. All our calculations can be tested in current cold atom experiments.

Lei Chen; Zhidong Zhang; Zhaoxin Liang

2015-01-28T23:59:59.000Z

53

Cosmological QCD phase transition in steady non-equilibrium dissipative Ho\\v{r}ava-Lifshitz early universe  

E-Print Network [OSTI]

We study the phase transition from quark-gluon plasma to hadrons in the early universe in the context of non-equilibrium thermodynamics. According to the standard model of cosmology, a phase transition associated with chiral symmetry breaking after the electro-weak transition has occurred when the universe was about $1-10\\mu s$ old. We focus attention on such a phase transition in the presence of a viscous relativistic cosmological background fluid in the framework of non-detailed balance Ho\\v{r}ava-Lifshitz cosmology within an effective model of QCD. We consider a flat Friedmann-Robertson-Walker Universe filled with a non-causal and causal bulk viscous cosmological fluid respectively and investigate the effects of the running coupling constants of Ho\\v{r}ava-Lifshitz gravity, $\\lambda$, on the evolution of the physical quantities relevant to a description of the early universe, namely, the temperature $T$, scale factor $a$, deceleration parameter $q$ and dimensionless ratio of the bulk viscosity coefficient ...

Khodadi, M

2014-01-01T23:59:59.000Z

54

Enhanced heat transfer through filler-polymer interface by surface-coupling agent in heat-dissipation material: A non-equilibrium molecular dynamics study  

SciTech Connect (OSTI)

Developing a composite material of polymers and micrometer-sized fillers with higher heat conductance is crucial to realize modular packaging of electronic components at higher densities. Enhancement mechanisms of the heat conductance of the polymer-filler interfaces by adding the surface-coupling agent in such a polymer composite material are investigated through the non-equilibrium molecular dynamics (MD) simulation. A simulation system is composed of ?-alumina as the filler, bisphenol-A epoxy molecules as the polymers, and model molecules for the surface-coupling agent. The inter-atomic potential between the ?-alumina and surface-coupling molecule, which is essential in the present MD simulation, is constructed to reproduce the calculated energies with the electronic density-functional theory. Through the non-equilibrium MD simulation runs, we find that the thermal resistance at the interface decreases significantly by increasing either number or lengths of the surface-coupling molecules and that the effective thermal conductivity of the system approaches to the theoretical value corresponding to zero thermal-resistance at the interface. Detailed analyses about the atomic configurations and local temperatures around the interface are performed to identify heat-transfer routes through the interface.

Tanaka, Kouichi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan); Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Kitsunezuka, Masashi; Shinma, Atsushi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan)

2013-11-21T23:59:59.000Z

55

Spin-polarization and spin-dependent logic gates in a double quantum ring based on Rashba spin-orbit effect: Non-equilibrium Green's function approach  

SciTech Connect (OSTI)

Spin-dependent electron transport in an open double quantum ring, when each ring is made up of four quantum dots and threaded by a magnetic flux, is studied. Two independent and tunable gate voltages are applied to induce Rashba spin-orbit effect in the quantum rings. Using non-equilibrium Green's function formalism, we study the effects of electron-electron interaction on spin-dependent electron transport and show that although the electron-electron interaction induces an energy gap, it has no considerable effect when the bias voltage is sufficiently high. We also show that the double quantum ring can operate as a spin-filter for both spin up and spin down electrons. The spin-polarization of transmitted electrons can be tuned from ?1 (pure spin-down current) to +1 (pure spin-up current) by changing the magnetic flux and/or the gates voltage. Also, the double quantum ring can act as AND and NOR gates when the system parameters such as Rashba coefficient are properly adjusted.

Eslami, Leila, E-mail: Leslami@iust.ac.ir; Esmaeilzadeh, Mahdi, E-mail: mahdi@iust.ac.ir [Department of Physics, Iran University of Science and Technology, Tehran 16846 (Iran, Islamic Republic of)

2014-02-28T23:59:59.000Z

56

Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe  

SciTech Connect (OSTI)

This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core.

Prevosto, L.; Mancinelli, B. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina)] [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina) [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina)

2013-12-15T23:59:59.000Z

57

Problems on Non-Equilibrium Statistical Physics  

E-Print Network [OSTI]

energy functional, similar to the problem in dimensional scaling in the H-atom. For the C-atom, we got the ground state energy -37:82 eV with a relative error less than 6 %. The simplest molecular ion, H+ 2 , has been investigated by the quasi...

Kim, Moochan

2011-08-08T23:59:59.000Z

58

: Non-Equilibrium Energy Research Center (NERC)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

be a central part of the human resources that the US requires to build a secure energy future based on understanding and creating new materials. The fundamental challenge and the...

59

Non-equilibrium thermodynamics of gravitational screens  

E-Print Network [OSTI]

We study the Einstein gravity equations projected on a timelike surface, which represents the time evolution of what we call a gravitational screen. We show that such a screen possesses a surface tension and an internal energy, and that the Einstein equations reduce to the thermodynamic equations of a viscous bubble. We also provide a complete dictionary between gravitational and thermodynamical variables. In the non-viscous cases there are three thermodynamic equations which characterise a bubble dynamics: These are the first law, the Marangoni flow equation and the Young-Laplace equation. In all three equations the surface tension plays a central role: In the first law it appears as a work term per unit area, in the Marangoni flow its gradient drives a force, and in the Young-Laplace equation it contributes to a pressure proportional to the surface curvature. The gravity equations appear as a natural generalization of these bubble equations when the bubble itself is viscous and dynamical. In particular, it shows that the mechanism of entropy production for the viscous bubble is mapped onto the production of gravitational waves. We also review the relationship between surface tension and temperature, and discuss the usual black-hole thermodynamics from this point of view.

Laurent Freidel; Yuki Yokokura

2014-05-19T23:59:59.000Z

60

Non-equilibrium Dynamics of DNA Nanotubes  

E-Print Network [OSTI]

to the power of craftsmanship in experimental physics, and showed me different approaches to data analysis. He is an extraordinary example of a scientist; so much so that my wife and I named our first daughter after him as our of ocean bubbles on Malibu beach with him and Damien Woods. I am very grateful to the rest of my thesis

Winfree, Erik

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

The Principle of Minimal Resistance in Non-Equilibrium Thermodynamics  

E-Print Network [OSTI]

Analytical models describing the motion of colloidal particles in given velocity fields are presented. In addition to local approaches, leading to well known master equations such as the Langevin and the Fokker-Planck equations, a global description based on path integration is reviewed. This shows that under very broad conditions, during its evolution a dissipative system tends to minimize its energy dissipation in such a way to keep constant the Hamiltonian time rate, equal to the difference between the flux-based and the force-based Rayleigh dissipation functions. At steady state, the Hamiltonian time rate is maximized, leading to a minimum resistance principle. In the unsteady case, we consider the relaxation to equilibrium of harmonic oscillators and the motion of a Brownian particle in shear flow, obtaining results that coincide with the solution of the Fokker-Planck and the Langevin equations.

Mauri, Roberto

2015-01-01T23:59:59.000Z

62

Non equilibrium dissipation-driven steady many-body entanglement  

E-Print Network [OSTI]

We study an ensemble of two-level quantum systems (qubits) interacting with a common electromagnetic field in proximity of a dielectric slab whose temperature is held different from that of some far surrounding walls. We show that the dissipative dynamics of the qubits driven by this stationary and out of thermal equilibrium (OTE) field, allows the production of steady many-body entangled states, differently from the case at thermal equilibrium where steady states are always non-entangled. By studying up to ten qubits, we point out the role of symmetry in the entanglement production, which is exalted in the case of permutationally invariant configurations. In the case of three qubits, we find a strong dependence of tripartite entanglement on the spatial disposition of the qubits, and in the case of six qubits, we find several highly entangled bipartitions where entanglement can, remarkably, survive for large qubit-qubit distances up to 100 $\\mu$m.

Bruno Bellomo; Mauro Antezza

2014-09-25T23:59:59.000Z

63

Non-equilibrium electroweak baryogenesis from preheating after inflation  

E-Print Network [OSTI]

We present a novel scenario for baryogenesis in a hybrid inflation model at the electroweak scale, in which the Standard Model Higgs field triggers the end of inflation. One of the conditions for successful baryogenesis, the departure from thermal equilibrium, is naturally achieved at the stage of preheating after inflation. The inflaton oscillations induce large occupation numbers for long-wavelength configurations of Higgs and gauge fields, which leads to a large rate of sphaleron transitions. We estimate this rate during the first stages of reheating and evaluate the amount of baryons produced due to a particular type of higher dimensional CP violating operator. The universe thermalizes through fermion interactions, at a temperature below critical, $T_{rh} < 100$ GeV, preventing the wash-out of the produced baryon asymmetry. Numerical simulations in (1+1) dimensions support our theoretical analysis.

Juan Garcia-Bellido; Dmitri Grigoriev; Alexander Kusenko; Mikhail Shaposhnikov

1999-03-08T23:59:59.000Z

64

Supersonic turbulent boundary layers with periodic mechanical non-equilibrium  

E-Print Network [OSTI]

. It was documented that proper roughness selection coupled with a sufficiently strong favorable pressure gradient produced regions of �negative� production in the transport of turbulent stress. This led to localized areas of significant turbulence stress...

Ekoto, Isaac Wesley

2007-04-25T23:59:59.000Z

65

High-Efficiency Solid State Cooling Technologies: Non-Equilibrium Asymmetic Thermoelectrics (NEAT) Devices  

SciTech Connect (OSTI)

BEETIT Project: Sheetak is developing a thermoelectric-based solid state cooling system to replace typical air conditioners that use vapor compression to cool air. With noisy mechanical components, vapor compression systems use a liquid refrigerant to circulate within the air conditioner, absorb heat, and pump the heat out into the external environment. With no noisy moving parts or polluting refrigerants, thermoelectric systems rely on an electrical current being passed through the junction of the two different conducting materials to change temperature. Using advanced semiconductor technology, Sheetak is improving solid state cooling systems by using proprietary thermoelectric materials along with other innovations to achieve significant energy efficiency. Sheetak’s new design displaces compressor-based technology; improves reliability; and decreases energy usage. Sheetak’s use of semiconductor manufacturing methods leads to less material use—facilitating cheaper production.

None

2010-09-01T23:59:59.000Z

66

New directions in fluid dynamics: non-equilibrium aerodynamic and microsystem flows  

Science Journals Connector (OSTI)

...shuttle re-entering the atmosphere, or create the optimum...High- temperature plasmas, used both for the...the order of 100500 MHz, to provide enough...2002 Modeling of the plasma jet of a stationary plasma thruster. J. Appl...

2003-01-01T23:59:59.000Z

67

A TWO-DIMENSIONAL, NON-EQUILIBRIUM, NUMERICAL MODEL OF AN ALKALI SEEDED  

E-Print Network [OSTI]

by Darrel Kim Robertson B.Sc. Physics with Space Science and Technology, Leicester University, 1995 can pass through the gas. The ions do not recombine so the energy required to create them cannot are treated as one uid and the heavy species as a second, with separate temperatures and a heat transfer rate

68

Non-equilibrium thermodynamics, maximum entropy production and Earth-system evolution  

Science Journals Connector (OSTI)

...presence of soil water on land at...acts as the generator that drives the continental water balance out...difference of atmospheric CO2 concentration...associated with generators radiative exchange...distance of atmospheric water vapour content...

2010-01-01T23:59:59.000Z

69

Non-equilibrium self-assembly of a filament coupled to ATP/GTP hydrolysis  

E-Print Network [OSTI]

We study the stochastic dynamics of growth and shrinkage of single actin filaments or microtubules taking into account insertion, removal, and ATP/GTP hydrolysis of subunits. The resulting phase diagram contains three different phases: a rapidly growing phase, an intermediate phase and a bound phase. We analyze all these phases, with an emphasis on the bound phase. We also discuss how hydrolysis affects force-velocity curves. The bound phase shows features of dynamic instability, which we characterize in terms of the time needed for the ATP/GTP cap to disappear as well as the time needed for the filament to reach a length of zero, i.e., (to collapse) for the first time. We obtain exact expressions for all these quantities, which we test using Monte Carlo simulations.

Padinhateeri Ranjith; David Lacoste; Kirone Mallick; Jean-Francois Joanny

2008-09-12T23:59:59.000Z

70

Non-equilibrium coherent vortex states and subharmonic giant Shapiro steps in Josephson junction arrays  

E-Print Network [OSTI]

This is a review of recent work on the dynamic response of Josephson junction arrays driven by dc and ac currents. The arrays are modeled by the resistively shunted Josephson junction model, appropriate for proximity effect junctions, including self-induced magnetic fields as well as disorder. The relevance of the self-induced fields is measured as a function of a parameter $\\kappa=\\lambda_L/a$, with $\\lambda_L$ the London penetration depth of the arrays, and $a$ the lattice spacing. The transition from Type II ($\\kappa>1$) to Type I ($\\kappa <1$) behavior is studied in detail. We compare the results for models with self, self+nearest-neighbor, and full inductance matrices. In the $\\kappa=\\infty$ limit, we find that when the initial state has at least one vortex-antivortex pair, after a characteristic transient time these vortices unbind and {\\it radiate} other vortices. These radiated vortices settle into a parity-broken, time-periodic, {\\em axisymmetric coherent vortex state} (ACVS), characterized by alternate rows of positive and negative vortices lying along a tilted axis. The ACVS produces subharmonic steps in the current voltage (IV) characteristics, typical of giant Shapiro steps. For finite $\\kappa$ we find that the IV's show subharmonic giant Shapiro steps, even at zero external magnetic field. We find that these subharmonic steps are produced by a whole family of coherent vortex oscillating patterns, with their structure changing as a function of $\\kappa$. In general, we find that these patterns are due to a break down of translational invariance produced, for example, by disorder or antisymmetric edge-fields. The zero field case results are in good qualitative agreement with experiments

Daniel Domínguez; Jorge V. José

1994-07-11T23:59:59.000Z

71

The Development of a Non-Equilibrium Dispersed Flow Film Boiling Heat Transfer Modeling Package.  

E-Print Network [OSTI]

??The dispersed flow film boiling (DFFB) heat transfer regime is important to several applications including cryogenics, rocket engines, steam generators, and in the safety analysis… (more)

Meholic, Michael

2011-01-01T23:59:59.000Z

72

Finite-Temperature Non-equilibrium Quasicontinuum Method based on Langevin Dynamics  

SciTech Connect (OSTI)

The concurrent bridging of molecular dynamics and continuum thermodynamics presents a number of challenges, mostly associated with energy transmission and changes in the constitutive description of a material across domain boundaries. In this paper, we propose a framework for simulating coarse dynamic systems in the canonical ensemble using the Quasicontinuum method (QC). The equations of motion are expressed in reduced QC coordinates and are strictly derived from dissipative Lagrangian mechanics. The derivation naturally leads to a classical Langevin implementation where the timescale is governed by vibrations emanating from the finest length scale occurring in the computational cell. The equations of motion are integrated explicitly via Newmark's ({beta} = 0; {gamma} = 1/2) method, leading to a robust numerical behavior and energy conservation. In its current form, the method only allows for wave propagations supported by the less compliant of the two meshes across a heterogeneous boundary, which requires the use of overdamped dynamics to avoid spurious heating due to reflected vibrations. We have applied the method to two independent crystallographic systems characterized by different interatomic potentials (Al and Ta) and have measured thermal expansion in order to quantify the vibrational entropy loss due to homogenization. We rationalize the results in terms of system size, mesh coarseness, and nodal cluster diameter within the framework of the quasiharmonic approximation. For Al, we find that the entropy loss introduced by mesh coarsening varies linearly with the element size, and that volumetric effects are not critical in driving the anharmonic behavior of the simulated systems. In Ta, the anomalies of the interatomic potential employed result in negative and zero thermal expansion at low and high temperatures, respectively.

Marian, J; Venturini, G; Hansen, B; Knap, J; Ortiz, M; Campbell, G

2009-05-08T23:59:59.000Z

73

Risk Assessment and Monitoring of Stored CO2 in Organic Rocks Under Non-Equilibrium Conditions  

SciTech Connect (OSTI)

The USA is embarking upon tackling the serious environmental challenges posed to the world by greenhouse gases, especially carbon dioxide (CO2). The dimension of the problem is daunting. In fact, according to the Energy Information Agency, nearly 6 billion metric tons of CO2 were produced in the USA in 2007 with coal-burning power plants contributing about 2 billion metric tons. To mitigate the concerns associated with CO2 emission, geological sequestration holds promise. Among the potential geological storage sites, unmineable coal seams and shale formations in particular show promise because of the probability of methane recovery while sequestering the CO2. However. the success of large-scale sequestration of CO2 in coal and shale would hinge on a thorough understanding of CO2's interactions with host reservoirs. An important parameter for successful storage of CO2 reservoirs would be whether the pressurized CO2 would remain invariant in coal and shale formations under reasonable internal and/or external perturbations. Recent research has brought to the fore the potential of induced seismicity, which may result in caprock compromise. Therefore, to evaluate the potential risks involved in sequestering CO2 in Illinois bituminous coal seams and shale, we studied: (i) the mechanical behavior of Murphysboro (Illinois) and Houchin Creek (Illinois) coals, (ii) thermodynamic behavior of Illinois bituminous coal at - 100oC ? T ? 300oC, (iii) how high pressure CO2 (up to 20.7 MPa) modifies the viscosity of the host, (iv) the rate of emission of CO2 from Illinois bituminous coal and shale cores if the cores, which were pressurized with high pressure (? 20.7 MPa) CO2, were exposed to an atmospheric pressure, simulating the development of leakage pathways, (v) whether there are any fractions of CO2 stored in these hosts which are resistance to emission by simply exposing the cores to atmospheric pressure, and (vi) how compressive shockwaves applied to the coal and shale cores, which were pressurized with high pressure CO2, determine the fate of sequestered CO2 in these cores. Our results suggested that Illinois bituminous coal in its unperturbed state, i.e., when not pressurized with CO2, showed large variations in the mechanical properties. Modulus varied from 0.7 GPa to 3.4 GPa even though samples were extracted from a single large chunk of coal. We did not observe any glass transition for Illinois bituminous coal at - 100oC ? T ? 300oC, however, when the coal was pressurized with CO2 at ambient ? P ? 20.7 MPa, the viscosity of the coal decreased and inversely scaled with the CO2 pressure. The decrease in viscosity as a function of pressure could pose CO2 injection problems for coal as lower viscosity would allow the solid coal to flow to plug the fractures, fissures, and cleats. Our experiments also showed a very small fraction of CO2 was absorbed in coal; and when CO2 pressurized coals were exposed to atmospheric conditions, the loss of CO2 from coals was massive. Half of the sequestered gas from the coal cores was lost in less than 20 minutes. Our shockwave experiments on Illinois bituminous coal, New Albany shale (Illinois), Devonian shale (Ohio), and Utica shale (Ohio) presented clear evidence that the significant emission of the sequestered CO2 from these formations cannot be discounted during seismic activity, especially if caprock is compromised. It is argued that additional shockwave studies, both compressive and transverse, would be required for successfully mapping the risks associated with sequestering high pressure CO2 in coal and shale formations.

Malhotra, Vivak

2014-06-30T23:59:59.000Z

74

Pattern-forming in non-equilibrium quantum systems and geometrical models of matter  

E-Print Network [OSTI]

for financial support, Robin- son College for its wonderful atmosphere and Cambridge for being such an excep- tional and inspiring place. iii Contents Declaration i Summary ii Acknowledgements iii Contents iv 1 Introduction 1 I Polaritons 7 2 Background Material... , and d the dimensionality of the system. If this condition is not satisfied, electrons and holes undergo a Mott transition, unbinding and forming an electron-hole plasma. Chapter 2. Background Material 13 polariton condensation is not a straightforward...

Franchetti, Guido

2014-01-07T23:59:59.000Z

75

Flux-difference split parabolized Navier-Stokes algorithm for non-equilibrium chemically reacting flows  

SciTech Connect (OSTI)

A flux-difference split explicit finite-difference algorithm is presented for solving the parabolized form of the equations governing three-dimensional nonequilibrium chemically reacting flows. The algorithm is based on an explicit noniterative, upwind space-marching scheme developed by Korte, but differs in that the unsteady Riemann problem, rather than the steady Riemann problem, is solved. The algorithm allows either a second or an approximately third-order accurate upwind treatment of the convection terms by employing the unsteady approximate Riemann solver of Roe. The source terms of the species transport equations are treated in either an explicit or implicit manner, and the species diffusion terms are modeled with either a Fickian or a multicomponent model. A validation of the algorithm is performed by comparing computational results with the 2-D Mach 14, 15 degree compression-corner data of Holden. The three-dimensional capability of the algorithm is demonstrated by computing Mach 2.7 flow over a swept wedge scramjet fuel injector, and three-dimensional reacting flow capability is demonstrated by a computing a shock-jet interaction concept for mixing and combustion enhancement. 34 refs.

White, J.A.; Korte, J.J.; Gaffney, R.L. Jr. (Analytical Services and Materials, Inc., Hampton, VA (United States) NASA, Langley Research Center, Hampton, VA (United States))

1993-01-01T23:59:59.000Z

76

Non-equilibrium correlation function of a reptating chain J. Noolandi and K. M. Hong  

E-Print Network [OSTI]

neutron scattering (SANS) results. J. Physique - LETTRES 45 (1984) L-149-L-157 Classification Physics small angle neutron scattering (SANS). Among the various theories for highly entangled polymer systems

Boyer, Edmond

77

A non-equilibrium model for fixed-bed multi-component adiabatic adsorption  

E-Print Network [OSTI]

!arise, i A Iie. therYe Lieu'L nod 1 of ti'ie ed:iabatic adeoi"ption. of !Iulti- pl: ro. "irponcrr'. s onto a fi/ted 'ned of adsorbate ie dovrelop~i for t!Ie ceso oi' rlilu", e solutiono. The . -, ortc3. consir '. . of a I . . u!&3 '3 . et ot n!In-11r... volume of adsorbate particle (cm /cm ) moles of solute 1 per mole of gas 1n the bulk gas influent concentration of solute 1, moles of 1/mole of gas initial solute concentration, moles of i/mole of gas I dimensionless solute concentrationy Ci Ci/Ci I...

Harwell, Jeffrey Harry

2012-06-07T23:59:59.000Z

78

Stochastic thermodynamics of fluctuating density fields: Non-equilibrium free energy differences under coarse-graining  

SciTech Connect (OSTI)

We discuss the stochastic thermodynamics of systems that are described by a time-dependent density field, for example, simple liquids and colloidal suspensions. For a time-dependent change of external parameters, we show that the Jarzynski relation connecting work with the change of free energy holds if the time evolution of the density follows the Kawasaki-Dean equation. Specifically, we study the work distributions for the compression and expansion of a two-dimensional colloidal model suspension implementing a practical coarse-graining scheme of the microscopic particle positions. We demonstrate that even if coarse-grained dynamics and density functional do not match, the fluctuation relations for the work still hold albeit for a different, apparent, change of free energy.

Leonard, T.; Lander, B.; Seifert, U. [II. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany)] [II. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany); Speck, T. [Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf (Germany)] [Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf (Germany)

2013-11-28T23:59:59.000Z

79

THE DEPLOYMENT OF ZIP NON-EQUILIBRIUM PHONON DETECTORS IN CDMS II  

E-Print Network [OSTI]

operating these Si and Ge Z-sensitive Ionization and Phonon (ZIP) detectors at the Stanford Underground Facility are reported. 1 Surface electron events The Cryogenic Dark Matter Search (CDMS) 1 utilizes

California at Berkeley, University of

80

Non-equilibrium raft-like membrane domains under continuous recycling  

E-Print Network [OSTI]

We present a model for the kinetics of spontaneous membrane domain (raft) assembly that includes the effect of membrane recycling ubiquitous in living cells. We show that the domains have a broad power-law distribution with an average radius that scales with the 1/4 power of the domain lifetime when the line tension at the domain edges is large. For biologically reasonable recycling and diffusion rates the average domain radius is in the tens of nm range, consistent with observations. This represents one possible link between signaling (involving rafts) and traffic (recycling) in cells. Finally, we present evidence that suggests that the average raft size may be the same for all scale-free recycling schemes.

Matthew S. Turner; Pierre Sens; Nicholas D. Socci

2005-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

The Influence of Hydraulic Non-Equilibrium on Pressure Plate Data  

SciTech Connect (OSTI)

Pressure plates are used routinely to measure water retention characteristics of soils. Plates of varying porosity are used depending on the pressure range of interest. For applied pressures up to 1.5 MPa, 15-bar porous ceramic plates with fine porosity are used because of their high bubbling pressure (>15 bar), which limits airflow through the plate. The typical saturated hydraulic conductivity of the 15-bar plate is less than 1x10-13 m s-1. Low plate conductance coupled with decreasing soil hydraulic conductivities (e.g., <1x10-13 m s-1) at high pressures strongly influence equilibrium times, which theoretically may extend to months or years. We measured the soil water pressures (suctions) for three soils, a sand, a silt loam, and a clay placed on 15-bar pressure plates for 10 days or longer, with and without static loads and with and without use of a kaolinite slurry for improved plate contact. Total matric suctions, inferred from peltier psychrometry data, were always less than 1.5 MPa. When sample height was increased from 1.5 cm to 3 cm, the water contents increased and total suctions decreased to 0.15 MPa for sand, 0.3 MPa for silt loam, and 0.55 MPa for clay. These data suggest that alternative methods to pressure plates may be require to measure equilibrium water suctions of soils in reasonable times in the 15-bar pressure range and that loading of the samples and use of kaolinite appear to be ineffective in speeding equilibrium.

Gee, Glendon W.; Ward, Anderson L.; Zhang, Z. F.; Campbell, Gaylon S.; Mathison, Jon B.

2002-08-15T23:59:59.000Z

82

Non-equilibrium synthesis of Fe-Cr-C-W alloy by laser cladding  

Science Journals Connector (OSTI)

Synthesis of Fe-Cr-C-W alloy using the laser cladding technique offered an opportunity to produce a ... and uniform microstructure. Use of preheating during laser cladding Fe-Cr-C-W provided crack-free ... carbid...

J. Choi; J. Mazumder

1994-09-01T23:59:59.000Z

83

Non-Equilibrium Magnetohydrodynamic Behavior of Plasmas having Complex, Evolving Morphology  

SciTech Connect (OSTI)

Our main activity has been doing lab experiments where plasmas having morphology and behavior similar to solar and astrophysical plasmas are produced and studied. The solar experiment is mounted on one end of a large vacuum chamber while the astrophysical jet experiment is mounted on the other end. Diagnostics are shared between the two experiments. The solar experiment produces arched plasma loops that behave very much like solar corona loops. The astrophysical jet experiment produces plasma jets that are very much like astrophysical jets. We have also done work on plasma waves, including general wave dispersions, and specific properties of kinetic Alfven waves and of whistler waves.

Bellan, Paul M. [Caltech] [Caltech

2014-03-13T23:59:59.000Z

84

NON-EQUILIBRIUM DYNAMICS OF MANY-BODY QUANTUM SYSTEMS: FUNDAMENTALS AND NEW FRONTIER  

SciTech Connect (OSTI)

Rapid progress in nanotechnology and naofabrication techniques has ushered in a new era of quantum transport experiments. This has in turn heightened the interest in theoretical understanding of nonequilibrium dynamics of strongly correlated quantum systems. This project has advanced the frontiers of understanding in this area along several fronts. For example, we showed that under certain conditions, quantum impurities out of equilibrium can be reformulated in terms of an effective equilibrium theory; this makes it possible to use the gamut of tools available for quantum systems in equilibrium. On a different front, we demonstrated that the elastic power of a transmitted microwave photon in circuit QED systems can exhibit a many-body Kondo resonance. We also showed that under many circumstances, bipartite fluctuations of particle number provide an effective tool for studying many-body physics—particularly the entanglement properties of a many-body system. This implies that it should be possible to measure many-body entanglement in relatively simple and tractable quantum systems. In addition, we studied charge relaxation in quantum RC circuits with a large number of conducting channels, and elucidated its relation to Kondo models in various regimes. We also extended our earlier work on the dynamics of driven and dissipative quantum spin-boson impurity systems, deriving a new formalism that makes it possible to compute the full spin density matrix and spin-spin correlation functions beyond the weak coupling limit. Finally, we provided a comprehensive analysis of the nonequilibrium transport near a quantum phase transition in the case of a spinless dissipative resonant-level model. This project supported the research of two Ph.D. students and two postdoctoral researchers, whose training will allow them to further advance the field in coming years.

DeMille, David; LeHur, Karyn

2013-11-27T23:59:59.000Z

85

Thermal non-equilibrium in dispersed flow film boiling in a vertical tube  

E-Print Network [OSTI]

The departure from thermal equilibrium between a dispersed liquid phase and its vapor at high quality during film boiling is investigated, The departure from equilibruim is manifested by the high resistance to heat transfer ...

Forslund, Robert Paul

1966-01-01T23:59:59.000Z

86

Adjoint-Based Aerothermodynamic Shape Design of Hypersonic Vehicles in Non-Equilibrium Flows  

E-Print Network [OSTI]

geometries with aerothermodynamic considerations in the presence of high-enthalpy, chemically reactive gas terms R Governing equation residual S Control surface T Temperature U Vector of conserved variables u. The hypersonic vehicle design process requires the synthesis of aerothermodynamic, structural, TPS material

Alonso, Juan J.

87

Oblique and conical shock similarity laws for non-equilibrium flows  

E-Print Network [OSTI]

OF SCIEiiCE January 1968 Tia jor Subject: Aerospace Engineering OBLIQUE AVD COii'ICAL SIIOCK SINILARITY IAWS FOR NOXi EQUILIBRIUM FLOATS A Thesis by JESSE LOUIS BOLSTER Approved as to stvle and content by: (Chairman o Com xtteeP ead o spar tmen... ) (SO) 35 For a dissociating diatomic gas, the conical shock similarity law becomes K&& (1-Q, ) ? ? L P [ED/(k(K&o Y ~) )] =. co st t (51) I where K i5 l9 '4 (R 20 2l (52) With these two relations, it is possible to scale the length...

Holster, Jesse Louis

1968-01-01T23:59:59.000Z

88

Thermo-chemical dynamics and chemical quasi-equilibrium of plasmas in thermal non-equilibrium  

SciTech Connect (OSTI)

We examine both processes of ionization by electron and heavy-particle impact in spatially uniform plasmas at rest in the absence of external forces. A singular perturbation analysis is used to study the following physical scenario, in which thermal relaxation becomes much slower than chemical reactions. First, electron-impact ionization is investigated. The dynamics of the system rapidly becomes close to a slow dynamics manifold that allows for defining a unique chemical quasi-equilibrium for two-temperature plasmas and proving that the second law of thermodynamics is satisfied. Then, all ionization reactions are taken into account simultaneously, leading to a surprising conclusion: the inner layer for short time scale (or time boundary layer) directly leads to thermal equilibrium. Global thermo-chemical equilibrium is reached within a short time scale, involving only chemical reactions, even if thermal relaxation through elastic collisions is assumed to be slow.

Massot, Marc [Laboratoire EM2C, UPR 288 CNRS - Ecole Centrale Paris (France); Graille, Benjamin [Laboratoire de Mathematiques d'Orsay, UMR 8628 CNRS - Universite Paris-Sud (France); Magin, Thierry E. [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics (Belgium)

2011-05-20T23:59:59.000Z

89

Non-equilibrium degassing and a primordial source for helium in ocean-island volcanism  

E-Print Network [OSTI]

Helge M. Gonnermann1 { & Sujoy Mukhopadhyay1 Radioactive decay of uranium and thorium produces 4 He in conjunction with radiogenic ingrowth of 4 He, which has led to a volatile-depleted upper mantle (MORB source

Mukhopadhyay, Sujoy

90

SciTech Connect: Fe Atomic Data for Non-equilibrium Ionization...  

Office of Scientific and Technical Information (OSTI)

Christopher L. Los Alamos National Laboratory; Hughes, John P. Rutgers University; Smith, Randall K. Smithsonian Astrophysical Observatory; Badenes, Carles University of...

91

Study of Methane Reforming in Warm Non-Equilibrium Plasma Discharges  

E-Print Network [OSTI]

Utilization of natural gas in remote locations necessitates on-site conversion of methane into liquid fuels or high value products. The first step in forming high value products is the production of ethylene and acetylene. Non-thermal plasmas, due...

Parimi, Sreekar

2012-02-14T23:59:59.000Z

92

Turbulent mixing and beyond: non-equilibrium processes from atomistic to astrophysical scales II  

Science Journals Connector (OSTI)

...knowledge for the design of experiments in high energy density plasmas and for simulations of inhomogeneous and anisotropic flows...RF. 1985 QED: the strange theory of light and matter. Princeton, NJ: Princeton University press.

2013-01-01T23:59:59.000Z

93

Non-equilibrium deposition of phase pure Cu{sub 2}O thin films at reduced growth temperature  

SciTech Connect (OSTI)

Cuprous oxide (Cu{sub 2}O) is actively studied as a prototypical material for energy conversion and electronic applications. Here we reduce the growth temperature of phase pure Cu{sub 2}O thin films to 300?°C by intentionally controlling solely the kinetic parameter (total chamber pressure, P{sub tot}) at fixed thermodynamic condition (0.25 mTorr pO{sub 2}). A strong non-monotonic effect of P{sub tot} on Cu-O phase formation is found using high-throughput combinatorial-pulsed laser deposition. This discovery creates new opportunities for the growth of Cu{sub 2}O devices with low thermal budget and illustrates the importance of kinetic effects for the synthesis of metastable materials with useful properties.

Subramaniyan, Archana, E-mail: asubrama@mymail.mines.edu [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States); Perkins, John D.; Lany, Stephan; Stevanovic, Vladan; Ginley, David S.; Zakutayev, Andriy [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); O’Hayre, Ryan P. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States)

2014-02-01T23:59:59.000Z

94

Materials Science and Engineering A 449451 (2007) 1217 Non-equilibrium solidification of concentrated FeGe alloys  

E-Print Network [OSTI]

, a Indian Institute of Science, Bangalore 560012, India b Indian Institute of Technology, Madras, Chennai­Ge binary alloy system consists of several critical points and ordered­disorder transitions and can be used to a fundamental parameter, known as melt undercooling. From the point of view of thermodynamics, undercooling

Srivastava, Kumar Vaibhav

95

Minimization of a free-energy-like potential for non-equilibrium flow systems at steady state  

Science Journals Connector (OSTI)

...Engl. transl. Brose, H. L.). New York, NY: Macmillan. Prigogine, I...irreversible processes, 3rd edn. New York, NY: Interscience. Prigogine...Sagan, D. 2005 Into the cool: energy flow, thermodynamics and life...

2010-01-01T23:59:59.000Z

96

Non-equilibrium and local detection of the normal fraction of a trapped two-dimensional Bose gas  

E-Print Network [OSTI]

-dimensional Bose gas, a quantity that generally differs from the Bose-Einstein condensed fraction. The idea-Einstein condensation [7]. A possibil- ity explored in [8] is to look at the response of a gas in a toroidal trap for atomic samples, as the superfluid core co-exists with an external ring of normal gas [10]. In p

97

Non-equilibrium Quantum Many-Body Green Function Formalism in the light of Quantum Information Theory  

E-Print Network [OSTI]

The following issues are discussed inspired by the recent paper of Kadanoff (arXiv: 1403:6162): (a) Construction of a generalized one-particle Wigner distribution (GWD) function (analog of the classical distribution function) from which the quantum kinetic equation due to Kadanoff and Baym (KB) is derived, often called the Quantum Boltzmann Equation (QBE); (b) The equation obeyed by this has a collision contribution in the form of a two-particle Green function. This term is manipulated to have Kinetic Entropy in parallel to its counterpart in the classical Boltzmann kinetic equation for the classical distribution function. This proved to be problematic in that unlike in the classical Boltzmann kinetic equation, the contribution from the kinetic entropy term was non-positive; (3) Kadanoff surmised that this situation could perhaps be related to quantum entanglement that may not have been included in his theory. It is shown that GWD is not positive everywhere (indicating dynamical quantumness) just like the commonly recognized property of the Wigner function (negative property indicating quantumness of the state). The issue of non-positive feature appearing in approximate evaluation of patently positive entities in many particle systems is here pointed to an early discussion of this issue (Phys. Rev. A10, 1852 (1974)) in terms of a theorem on truncation of cumulant expansion of a probability distribution function due to Marcinkeiwicz. The last issue of presence or absence of entanglement in an approximate evaluation of a many particle correlation poses a new problem; it is considered here in terms of fermionic entanglement theory in the light of density matrix and Green function theory of many-fermion systems. The clue comes from the fact that the Hartree-Fock approximation exhbits no entantanglement in two-particle fermion density matrix and hence also in two-particle Green function.

A. K. Rajgaopal

2014-05-12T23:59:59.000Z

98

Generation of Teflon-like layers on cellophane surfaces under atmospheric pressure non-equilibrium SF6-plasma environments  

Science Journals Connector (OSTI)

In this contribution a novel atmospheric pressure SF6–cold–plasma method is suggested for the conversion of... x , (x< 6 ) species generated in the discharge for oxygen extractio...

L. E. Cruz-Barba; S. Manolache; F. Denes

2003-07-01T23:59:59.000Z

99

Non-equilibrium synthesis, structure, and opto-electronic properties of Cu2?2x Zn x O alloys  

Science Journals Connector (OSTI)

Alloying in traditional semiconductors is a well-established method to tune the electronic structure and the materials properties, but this technique is less common for oxides. Here, we present results on the ...

Archana Subramaniyan; John D. Perkins; Ryan P. O’Hayre…

2014-11-01T23:59:59.000Z

100

Steady-state film-boiling data in rod-bundle geometry and non-equilibrium correlation assessment  

SciTech Connect (OSTI)

A series of 22 steady-state, rod bundle, dispersed flow film boiling experiments has been performed in the Thermal-Hydraulic Test Facility (THTF), a pressurized-water loop containing 64 full-length electrically heated rods. Test parameters in the upflow experiments cover a wide range of conditions typical of those which might be encountered during a nuclear reactor loss-of-coolant accident. Local equilibrium fluid conditions were calculated using mass and energy conservation considerations. Experimentally determined heat transfer coefficients were compared to several available film boiling heat transfer correlations: Dougall-Rohsenow, Groeneveld 5.7, Groeneveld-Delorme, Chen, Jones-Zuber, and Yoder-Rohsenow. The Groeneveld 5.7 correlation tended to predict the data better than any other correlation tested. The Dougall-Rohsenow correlation tends to overpredict the data while the Yoder-Rohsenow correlation predicted the data better than the other nonequilibrium correlations examined. However, all of the nonequilibrium correlations generally underpredict the heat transfer.

Yoder, G.L.; Morris, D.G.; Mullins, C.B.; Ott, L.J.; Reed, D.A.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Chemical freeze-outs of strange and non-strange particles and residual chemical non-equilibrium  

E-Print Network [OSTI]

We propose an elaborate version of the hadron resonance gas model with the combined treatment of separate chemical freeze-outs for strange and non-strange hadrons and with an additional \\gamma_{s} factor which accounts for the remaining strange particle non-equilibration. Two sets of chemical freeze-outs parameters are connected by the conservation laws of entropy, baryonic charge, isospin projection and strangeness. The developed approach enables us to perform a high-quality fit of the hadron multiplicity ratios for AGS, SPS and RHIC energies with total \\chi^2/dof \\simeq 1.05. A special attention is paid to a complete description of the Strangeness Horn. A well-known \\bar p, \\bar \\Lambda and \\bar \\Xi selective suppression problem is also discussed.

K. A. Bugaev; D. R. Oliinychenko; V. V. Sagun; A. I. Ivanytskyi; J. Cleymans; E. G. Nikonov; G. M. Zinovjev

2013-12-18T23:59:59.000Z

102

Within-island differentiation and between-island homogeneity: non-equilibrium population structure in the seaweed  

E-Print Network [OSTI]

Gran Canaria, Campus Universitario de Tafira, 35017 Las Palmas de Gran Canaria, Spain (Received 12 June. In a previous study on Gran Canaria, small-scale dispersal distances were found to be limited to 55 m correlation for Gran Canaria and Tenerife but not for Fuerteventura. In contrast, there was no detectable IBD

103

Evaluation of technical feasibility of closed-cycle non-equilibrium MHD power generation with direct coal firing. Final report, Task 1  

SciTech Connect (OSTI)

Program accomplishments in a continuing effort to demonstrate the feasibility of direct coal fired, closed cycle, magnetohydrodynamic power generation are detailed. These accomplishments relate to all system aspects of a CCMHD power generation system including coal combustion, heat transfer to the MHD working fluid, MHD power generation, heat and cesium seed recovery and overall systems analysis. Direct coal firing of the combined cycle has been under laboratory development in the form of a high slag rejection, regeneratively air cooled cyclone coal combustor concept, originated within this program. A hot bottom ceramic regenerative heat exchanger system was assembled and test fired with coal for the purposes of evaluating the catalytic effect of alumina on NO/sub x/ emission reduction and operability of the refractory dome support system. Design, procurement, fabrication and partial installation of a heat and seed recovery flow apparatus was accomplished and was based on a stream tube model of the full scale system using full scale temperatures, tube sizes, rates of temperature change and tube geometry. Systems analysis capability was substantially upgraded by the incorporation of a revised systems code, with emphasis on ease of operator interaction as well as separability of component subroutines. The updated code was used in the development of a new plant configuration, the Feedwater Cooled (FCB) Brayton Cycle, which is superior to the CCMHD/Steam cycle both in performance and cost. (WHK)

Not Available

1981-11-01T23:59:59.000Z

104

Evaluation of technical feasibility of closed-cycle non-equilibrium MHD power generation with direct coal firing. Final report, Task I  

SciTech Connect (OSTI)

Program accomplishments in a continuing effort to demonstrate the feasibility of direct coal-fired, closed-cycle MHD power generation are reported. This volume contains the following appendices: (A) user's manual for 2-dimensional MHD generator code (2DEM); (B) performance estimates for a nominal 30 MW argon segmented heater; (C) the feedwater cooled Brayton cycle; (D) application of CCMHD in an industrial cogeneration environment; (E) preliminary design for shell and tube primary heat exchanger; and (F) plant efficiency as a function of output power for open and closed cycle MHD power plants. (WHK)

Not Available

1981-11-01T23:59:59.000Z

105

Towards a kinetic understanding of the ignition of air-propane mixture by a non-equilibrium discharge: the decomposition mechanisms of propane  

Science Journals Connector (OSTI)

The decomposition of propane in non-thermal plasmas of N2/C3H8 and N2/O2/C3H8 mixtures (oxygen percentage up to 20%) at low temperature is studied in a photo-triggered discharge. Quenching of nitrogen metastable states dissociate C3H8 to produce propene and hydrogen. Oxidation reactions are growing in importance when the O2 concentration increases, but the dissociation quenching reactions still occurs for the air-based mixture. Even for a low concentration of oxygen, OH is an important specie involved in the conversion of the hydrocarbon. A kinetic analysis emphasises that OH comes in great part from the production of H, in which the methyl radical plays a role, strengthening the role of the dissociation processes of propane and propene in the medium reactivity. Results of PLIF measurements performed on OH during the diffuse afterglow of a nanosecond corona discharge correlate with results obtained on the photo-triggered discharge.

Stéphane Pasquiers; Sabrina Bentaleb; Pascal Jeanney; Nicole Blin-Simiand; Pierre Tardiveau; Lionel Magne; Katell Gadonna; Nicolas Moreau; François Jorand

2013-01-01T23:59:59.000Z

106

Abbreviations: IEF, isoelectric focussing; NEPHGE, non-equilibrium pH gradient electrophoresis; PAGE, polyacrylamide gel electrophoresis; pI, isoelectric point; SDS, sodium dodecyl sulphate; SI, self-incompatibility; 1-D, 1 dimensional; 2-D, 2 dimensional  

E-Print Network [OSTI]

; PAGE, polyacrylamide gel electrophoresis; pI, isoelectric point; SDS, sodium dodecyl sulphate; SI, self-incompatibility@yorku.ca Keywords: cysteine protease, -expansin, mass spectrometry, self-incompatibility ABSTRACT Distylous species of Turnera are strongly self-incompatible, therefore they provide an excellent system for investigations

Shore, Joel S.

107

Nonequilibrium quantum kinetics  

SciTech Connect (OSTI)

This paper contains viewgraphs on non-equilibrium quantum kinetics of nuclear reactions at the intermediate and high energy ranges.

Danielewicz, P.

1997-09-22T23:59:59.000Z

108

E-Print Network 3.0 - action potential energy Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in the design of a practical energy ... Source: California Energy Commission Collection: Energy Storage, Conversion and Utilization 3 FIGURE 12. To create a non-equilibrium a...

109

X-ray Diffuse Scattering Measurements of Nucleation Dynamics...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

X-ray Diffuse Scattering Measurements of Nucleation Dynamics at Femtosecond Resolution Real-time measurement and control of the non-equilibrium properties of materials represents...

110

Center for Turbulence Research Proceedings of the Summer Program 2008  

E-Print Network [OSTI]

of plasmas in thermal and chemical non-equilibrium. Finally, derivation of the Saha equation, describing chem. Massot a suitable thermodynamics for plasmas and extend the Saha equation to thermal non- equilibrium plasmas for atmospheric entry flows based on kinetic theory By B. Graille, T. E. Magin AND M. Massot We

Prinz, Friedrich B.

111

IOP PUBLISHING JOURNAL OF PHYSICS D: APPLIED PHYSICS J. Phys. D: Appl. Phys. 40 (2007) 31453154 doi:10.1088/0022-3727/40/10/018  

E-Print Network [OSTI]

approach to generate uniform non-equilibrium atmospheric-pressure glow discharges. We report run (atmospheric) pressure operation with a high degree of plasma uniformity over cm length scales and a high degree of thermal and chemical non-equilibrium have been successfully exploited in a number of new

Raja, Laxminarayan L.

112

Transcription factors SOX4 and SOX11 function redundantly to regulate the development of mouse retinal ganglion cells  

E-Print Network [OSTI]

Lerner Institute, Cleveland Clinic, Cleveland, OH 44195 4 College of Life and Environmental Sciences layer while deletion of Brn3b has no effect on the expression of Sox4 and Sox11. Taken together layers: photoreceptors (rods and cones) constitute the outer nuclear layer (ONL); horizontal, bipolar

113

Two-Temperature Two-Dimensional Non Chemical Equilibrium Modeling of Ar–CO2–H2 Induction Thermal Plasmas at Atmospheric Pressure  

Science Journals Connector (OSTI)

Here the authors developed a two-dimensional two-temperature chemical non-equilibrium (2T-NCE) model of Ar–...2–H2 inductively coupled thermal plasmas (ICTP) around atmospheric pressure (760 torr). Assuming 22 di...

Sharif Abdullah Al-Mamun; Yasunori Tanaka…

2010-02-01T23:59:59.000Z

114

Gordon Research Conferences  

Science Journals Connector (OSTI)

...Liang, "The Structure and Phase Behavior of Self-Assembled Monolay-ers...Equilibrium and Non-Equilibrium Behavior." Symmetry Consideration in Phase Tran-sitions: J. Lajzerowicz...Complexity in Diblock Copolymer Phase Behavior." Theory and Experiments...

Carlyle B. Storm

1994-02-18T23:59:59.000Z

115

Modeling Studies of Atmospheric Pressure Microplasmas: Plasma Dynamics, Surface Interaction and Applications.  

E-Print Network [OSTI]

??Technologies based on atmospheric-pressure microplasmas (APMs) have been widely developed due to the unique nature microplasmas being non-equilibrium and its ability to operate stably at… (more)

Wang, Jun-Chieh

2014-01-01T23:59:59.000Z

116

Interactions of Non-Thermal Atmospheric Pressure Plasma with Solid and Liquid Food Systems: A Review  

Science Journals Connector (OSTI)

Non-equilibrium atmospheric pressure plasma processes combine several advantages such as non- ... science and technology dealing with the application of plasma processes on solid and liquid foodstuff. Starting wi...

Björn Surowsky; Oliver Schlüter; Dietrich Knorr

2014-07-01T23:59:59.000Z

117

Granular Thermodynamics  

E-Print Network [OSTI]

We present experimental evidence for a strong analogy between quasi-2D uniform non-equilibrium steady states (NESS) of excited granular materials and equilibrium thermodynamics. Under isochoric conditions we find that the ...

Shattuck, M. D.

118

Diesel Engine Advanced Multi-Mode Combustion Control and Generalized Nonlinear Transient Trajectory Shaping Control Methods.  

E-Print Network [OSTI]

?? This dissertation addresses the Diesel engine advanced combustion mode switching transient control and the generalized nonlinear non-equilibrium transient trajectory shaping (NETTS) control problem.Control-oriented models… (more)

Yan, Fengjun

2012-01-01T23:59:59.000Z

119

Spin coherence transfer in chemical transformations monitored NMR  

E-Print Network [OSTI]

the transfer of spin coherence in non-equilibrium chemicalK. L. Pierce, A. Pines ? Spin coherence transfer in chemical10.1002/anie.200123456 Spin Coherence Transfer in Chemical

Anwar, Sabieh M.; Hilty, Christian; Chu, Chester; Bouchard, Louis-S.; Pierce, Kimberly L.; Pines, Alexander

2006-01-01T23:59:59.000Z

120

Thermodynamics with 3 Spins  

E-Print Network [OSTI]

Glauber dynamics, applied to the one-dimensional Ising model, provides a tractable model for the study of non-equilibrium, many-body processes driven by a heat bath

Eward May; Jack L. Uretsky

2009-12-21T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Simulation of Self-Organized States in Combustion Processes  

Science Journals Connector (OSTI)

Recently, the problem of self-organization in non-equilibrium systems has intensively been discussed [l, 2, 3]. The major role in the process of successive generation and formation of more complicated temporal...

L. U. Artyukh; P. G. Itskova…

1984-01-01T23:59:59.000Z

122

Plasma-assisted ignition and deflagration-to-detonation transition  

Science Journals Connector (OSTI)

...Forman A. Williams Plasma-assisted ignition...correspondence ( astariko@princeton.edu ). 1 Mechanical...Aerospace Engineering, Princeton University, , Princeton, NJ-08544, USA...Non-equilibrium plasma demonstrates great...

2012-01-01T23:59:59.000Z

123

A mathematical and experimental study of caustic flooding  

E-Print Network [OSTI]

: Dr. Ching Buang Wu A simple non-equilibrium chemical displacement model for continuous, linear, caustic flooding of crude oil is presented. The laboratory experiments were conducted to support the numerical simulation and to verify the results.... The unique feature of this mathematic study is that it includes the chemistry of the acid hydrolysis to produce surfactants and the chemical reaction rate under the non- equilibrium state. The in-situ generated surfactant was presumed to alter the oil...

Shen, Tsu-Cheng

1985-01-01T23:59:59.000Z

124

Thermodynamics in f(R) gravity in the Palatini formalism  

SciTech Connect (OSTI)

We investigate thermodynamics of the apparent horizon in f(R) gravity in the Palatini formalism with non-equilibrium and equilibrium descriptions. We demonstrate that it is more transparent to understand the horizon entropy in the equilibrium framework than that in the non-equilibrium one. Furthermore, we show that the second law of thermodynamics can be explicitly verified in both phantom and non-phantom phases for the same temperature of the universe outside and inside the apparent horizon.

Bamba, Kazuharu; Geng, Chao-Qiang, E-mail: bamba@phys.nthu.edu.tw, E-mail: geng@phys.nthu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu, 300 Taiwan (China)

2010-06-01T23:59:59.000Z

125

Assessment of reaction-rate predictions of a collision-energy approach for chemical reactions in atmospheric flows.  

SciTech Connect (OSTI)

A recently proposed approach for the Direct Simulation Monte Carlo (DSMC) method to calculate chemical-reaction rates is assessed for high-temperature atmospheric species. The new DSMC model reproduces measured equilibrium reaction rates without using any macroscopic reaction-rate information. Since it uses only molecular properties, the new model is inherently able to predict reaction rates for arbitrary non-equilibrium conditions. DSMC non-equilibrium reaction rates are compared to Park's phenomenological nonequilibrium reaction-rate model, the predominant model for hypersonic-flow-field calculations. For near-equilibrium conditions, Park's model is in good agreement with the DSMC-calculated reaction rates. For far-from-equilibrium conditions, corresponding to a typical shock layer, significant differences can be found. The DSMC predictions are also found to be in very good agreement with measured and calculated non-equilibrium reaction rates, offering strong evidence that this is a viable and reliable technique to predict chemical reaction rates.

Gallis, Michail A.; Bond, Ryan Bomar; Torczynski, John Robert

2010-06-01T23:59:59.000Z

126

LFS Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Page 1 of 31 Page 1 of 31 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

127

RussiaSNL2-web.indd  

National Nuclear Security Administration (NNSA)

Extending Non-Equilibrium Molecular Dynamics Extending Non-Equilibrium Molecular Dynamics Simulation Methods Principal Investigators: John Aidun (SNL) and Genri Norman (JIHT) Project Description Novel nonequilibrium molecular dynamics (NEMD) simulation methods are being extended and applied in four areas of mutual interest to Sandia and Joint Institute for High Temperatures, Russian Academy of Sciences (JIHT RAS). NEMD is being applied to (1) understanding relaxation and equilibration in non-ideal, nondegenerate plasmas; (2) characterizing melting or cavitation of condensed matter systems that are super-heated or under hydrostatic tension; (3) devising classical interaction potentials that can represent changing bonding character as a system evolves; and (4) investigating the mechanisms of

128

Boltzmann-Equation Based Derivation of Balance Laws in Irreversible Thermodynamics  

E-Print Network [OSTI]

In this paper we propose a novel approach to construct macroscopic balance equations and constitutive equations describing various irreversible phenomena. It is based on the general principles of non-equilibrium thermodynamics and consists of four basic steps: picking suitable state variables, choosing a strictly concave entropy function, separating entropy fluxes and production rates properly, and determining a dissipation matrix. Our approach takes the advantage of both EIT and GENERIC formalisms, and shows a direct correspondence with Levermore's moment closure hierarchies for the Boltzmann equation. This result may put various macroscopic modeling approaches starting from the general principles of non-equilibrium thermodynamics on a solid microscopic foundation based on the Boltzmann equation.

Hong, Liu; Zhu, Yi; Yong, Wen-An

2014-01-01T23:59:59.000Z

129

The mechano-chemistry of cytoskeletal force generation  

E-Print Network [OSTI]

In this communication, we propose a model to study the non-equilibrium process by which actin stress fibers develop force in contractile cells. The emphasis here is on the non-equilibrium thermodynamics, which is necessary to address the mechanics as well as the chemistry of dynamic cell contractility. In this setting we are able to develop a framework that relates (a) the dynamics of force generation within the cell and (b) the cell response to external stimuli to the chemical processes occurring within the cell, as well as to the mechanics of linkage between the stress fibers, focal adhesions and extra-cellular matrix.

Mirko Maraldi; Krishna Garikipati

2014-04-23T23:59:59.000Z

130

Infrared and reflectron time-of-flight mass spectroscopic study on the synthesis of  

E-Print Network [OSTI]

sublimation profiles obtained from the ReTOF spectra and infrared spectroscopy of the Department of Chemistry in the formation of glycolaldehyde via non-equilibrium chemistry, which were identified as follows: (i) radical of glycolaldehyde formed, suggesting further thermal chemistry of trapped radicals within the ice matrix

Kaiser, Ralf I.

131

State and Transition Modeling History & Current Concepts  

E-Print Network [OSTI]

management input · Friedel(1991) concentrated on thresholds ­ "...compatible with state and transition theoryState and Transition Modeling History & Current Concepts Tamzen K. Stringham Oregon State vegetation change #12;· Non-equilibrium Models (States, Transitions and Thresholds) ­ Encompass Range

132

Proceedings of Institute of Mathematics of NAS of Ukraine 2000, Vol. 30, Part 1, 231238. Modelling System for Relaxing Media.  

E-Print Network [OSTI]

Proceedings of Institute of Mathematics of NAS of Ukraine 2000, Vol. 30, Part 1, 231­238. Modelling.A. VLADIMIROV Division of Geodynamics of Explosion, Subbotin Institute of Geophysics, NAS of Ukraine, Khmelnicki Str. 63-B, Kyiv 54, Ukraine E-mail: vsan@ambernet.kiev.ua A model describing non-equilibrium processes

Popovych, Roman

133

> 2006 International Symposium on Electrohydrodynamics -Buenos Aires-4th December 2006 <  

E-Print Network [OSTI]

atmospheric plasma discharge to be an effective means of air flow control. In supersonic airflow it seems that the effects of the plasma are mainly of thermal origin of the existence of non thermal effect in non equilibrium weakly ionized gases. The nature of the observed effects

Paris-Sud XI, Université de

134

Tunable soft structure in charged fluids confined by dielectric interfaces  

Science Journals Connector (OSTI)

...56), or the non-equilibrium...and quantify the thermal forces in fluids...such as the atmospheric chemistry, colloid...one-component plasma up to {gamma...statistical mechanics of non-uniform, classical...Rev E Stat Phys Plasmas Fluids Relat...The interplay of thermal motion, short-range...

Jos W. Zwanikken; Monica Olvera de la Cruz

2013-01-01T23:59:59.000Z

135

Vacuum 71 (2003) 417436 The barrier discharge: basic properties and applications to  

E-Print Network [OSTI]

discharge; Non-equilibrium plasma; Cross-correlation spectroscopy; Atmospheric pressure glow discharge field of applications are the non-thermal plasma condi- tions at low gas temperatures and at elevated-equilibrium plasmas in a controllable way at atmospheric pressure, and at moderate gas temperature. They provide

Greifswald, Ernst-Moritz-Arndt-Universität

136

IOP PUBLISHING JOURNAL OF PHYSICS D: APPLIED PHYSICS J. Phys. D: Appl. Phys. 43 (2010) 185206 (12pp) doi:10.1088/0022-3727/43/18/185206  

E-Print Network [OSTI]

followed in the use of non- thermal atmospheric pressure plasmas in medicine. In the first, the plasma. Introduction Non-equilibrium, atmospheric pressure plasma treatment of living tissue is being used in a variety at stacks.iop.org/JPhysD/43/185206 Abstract The application of atmospheric pressure plasmas to human tissue

Kushner, Mark

137

Solar Plasma Spectroscopy: Achievements and Future Challenges 13-15 September 2010  

E-Print Network [OSTI]

intensities of Si III lines in the transition region? 15:00 - 15:15 Jaroslav Dudik The effect of non-thermal Watanabe Iron Line Diagnostics of Non-Equilibrium Plasma in Solar and Laboratory Plasmas 17:00 - 17 for non-thermal electron excitation of coronal ions 09:20 - 09:40 Brian Fawcett Some foundations

Cambridge, University of

138

1 2010 Heliophysics Decadal ReviewScience with a X-ray Microcalorimeter White Paper Science Objectives for an X-Ray Microcalorimeter Observing the Sun  

E-Print Network [OSTI]

such as the detection of microheat- ing in active regions, ion-resolved velocity flows, and the presence of non-thermal to revolutionize our understanding of coronal plasmas, specifically with regard to the non-equilibrium plasma of interest for detailed stud- ies of the fundamental plasma physics in the Sun's atmosphere, with excellent

Savin, Daniel Wolf

139

High-Energy Charged Particles in the Innermost Jovian Magnetosphere  

Science Journals Connector (OSTI)

...samples 10 plasma torus-1...lo and its plasma torus...vectors have large angles relative...and about non-radiative...sensitive area of 6.2...C, so no thermal noise...relatively large at the beginning...through an atmospheric region that...producing non-equilibrium...frequency (RF) pulses...

H. M. Fischer; E. Pehlke; G. Wibberenz; L. J. Lanzerotti; J. D. Mihalov

1996-05-10T23:59:59.000Z

140

Gordon Research Conferences  

Science Journals Connector (OSTI)

...Comsa, "Thermal helium scattering...moderately large deformations...leader). Non-accelera-tor...Effects of atmospheric oxida-tion...sperm-egg plasma membrane fusion...Bala-ban, "Large-scale protein...Space Plasma Physics Proctor...Dynamical non-equilibrium...magneti-cally confined plasmas"; M. Rush-bridge...

Alexander M. Cruickshank

1985-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Relationship between structural changes and hyperpolarized gas magnetic resonance imaging in chronic obstructive pulmonary disease using computational simulations with realistic alveolar geometry  

Science Journals Connector (OSTI)

...specific. Areas of emphysema...providing a non-invasive...into blood plasma and erythrocytes...the small thermal equilibrium...radiofrequency (RF) pulse, the non-equilibrium...uniform 180 RF pulse. The...voxel is so large, compared...of healthy non-smokers...in air at atmospheric pressure...total surface area similar to...

2009-01-01T23:59:59.000Z

142

Generalized longitudinal susceptibility for magnetic monopoles in spin ice  

Science Journals Connector (OSTI)

...non-equilibrium physics of the Wien effect...is related to the rate of change of magnetization...and he derived the rate of entropy production...3) contains much physics and deserves subtle...0. Thus, as we pass from low to high...monopoles hopping at a rate nu 0 located near...

2012-01-01T23:59:59.000Z

143

DOI 10.1140/epje/i2002-10149-2 Eur. Phys. J. E 11, 99104 (2003)  

E-Print Network [OSTI]

) gases [1] driven into a non-equilibrium steady state by a suitable injection of energy define/2 [3,4,6] (here v0 is the "thermal" r.m.s. velocity). This behavior was observed for the horizontal injection, considering idealized homo- geneous systems of inelastic hard spheres (given the exper- imen

Barrat, Alain

144

Generalized dynamical density functional theory for classical fluids and the significance of inertia and hydrodynamic interactions  

E-Print Network [OSTI]

We study the dynamics of a colloidal fluid including inertia and hydrodynamic interactions, two effects which strongly influence the non-equilibrium properties of the system. We derive a general dynamical density functional theory (DDFT) which shows very good agreement with full Langevin dynamics. In suitable limits, we recover existing DDFTs and a Navier-Stokes-like equation with additional non-local terms.

Benjamin D. Goddard; Andreas Nold; Nikos Savva; Grigorios A. Pavliotis; Serafim Kalliadasis

2012-08-08T23:59:59.000Z

145

Fisher Waves and Front Roughening in a Two-Species Invasion Model with Preemptive Competition  

E-Print Network [OSTI]

Fisher Waves and Front Roughening in a Two-Species Invasion Model with Preemptive Competition L. O study roughening of the front, using the framework of non-equilibrium interface growth. Our analysis indicates that initially flat, linear invading fronts exhibit Kardar-Parisi-Zhang (KPZ) roughening in one

Caraco, Thomas

146

M – Goldschmidt Abstracts 2011  

Science Journals Connector (OSTI)

...energy dispersion, and uranium oxide speciation. Goldschmidt...vegetation. Nearby, depleted "13 C31 values and...Fe, Ca, and Al to depleted protoliths. The distribution...refertilization of the highly depleted SCLM and the introduction...for non-equilibrium uranium, attempted to assess...

147

Electrons, life and the evolution of Earth's oxygen cycle  

E-Print Network [OSTI]

, Rutgers University, New Brunswick, NJ 08901, USA The biogeochemical cycles of H, C, N, O and S are coupled-compete denitrification, a new stable electron `market' emerged in which oxygenic photosynthesis and aerobic respiration of energy. The hallmark of biological energy transduction is non-equilibrium redox chemi- stry. Indeed

148

Heat transfer in soft nanoscale interfaces: the influence of interface curvature  

E-Print Network [OSTI]

Heat transfer in soft nanoscale interfaces: the influence of interface curvature Anders Lervik transient non-equilibrium molecular-dynamics simulations, heat-transfer through nanometer-scale interfaces processes. We show that the modeling of heat transfer across a nanodroplet/fluid interface requires

Kjelstrup, Signe

149

OSP WEEKLY FUNDING BULLETIN Volume 4, Issue 47 November 29, 2010  

E-Print Network [OSTI]

(RFP) is to be coordinated by the Gulf of Mexico Research Alliance (GOMA) and is about to be finalized. 2 Purpose: AFOSR announces a fiscal year 2011 competition for research to promote and sustain of high electric and magnetic fields; high energy density non-equilibrium processes. Advanced X

Alabama in Huntsville, University of

150

Titel. Author(s) Copyright 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim  

E-Print Network [OSTI]

semiconductor lasers [56], inertial confinement [67], combustion [81], and chemical reactions [10], could Many physical, chemical, and biological systems of interest evolve in a non- equilibrium environment as open-loop control. In contrast, the closed-loop control is based on feedback: it aims to stabilize

Handel, Andreas

151

JOURNAL DE PHYSIQUE Colloque C2, supplbment au no 6, Tome 48, juin 1987  

E-Print Network [OSTI]

JOURNAL DE PHYSIQUE Colloque C2, supplbment au no 6, Tome 48, juin 1987 DIRAC-BRUECKNER APPROACH matiere nucldaire en Lquilibre et non-6quilibre bas6 sur la methode Dirac-Brueckner. L'dquation cindtique of equilibrium and non-equilibrium phenoma in nuclear matter based on the Dirac-Brueckner approach. The resulting

Paris-Sud XI, Université de

152

Plasma-Enhanced Combustion of Hydrocarbon Fuels and Fuel Blends Using Nanosecond Pulsed Discharges  

SciTech Connect (OSTI)

This project had as its goals the study of fundamental physical and chemical processes relevant to the sustained premixed and non-premixed jet ignition/combustion of low grade fuels or fuels under adverse flow conditions using non-equilibrium pulsed nanosecond discharges.

Cappelli, Mark; Mungal, M Godfrey

2014-10-28T23:59:59.000Z

153

An adaptive grid refinement strategy for the simulation of negative streamers  

E-Print Network [OSTI]

to high electric fields, non-equilibrium ionization pro- cesses, so-called discharges, occur. They may and on the pressure and volume of the medium. One distinguishes the dark, glow or arc discharges that are stationary of negative streamers during electric breakdown of a non-attaching gas can be described by a two-fluid model

Ebert, Ute

154

Consistent Comparison of Macroscopic and State-to-State Kinetics in Hypersonic Flows  

E-Print Network [OSTI]

Consistent Comparison of Macroscopic and State-to-State Kinetics in Hypersonic Flows Gianpiero of Chemistry, Bari, 70126, Italy We present a comparison of numerical results in strongly expanding hypersonic variable in non-equilibrium condi- tions, per unit mass I. Introduction In supersonic and hypersonic flows

D'Ambrosio, Domenic

155

doi: 10.1149/2.048212jes 2012, Volume 159, Issue 12, Pages A1967-A1985.J. Electrochem. Soc.  

E-Print Network [OSTI]

and optimized. In the case of electrochemical energy storage devices, such as batteries, fuel cells in conjunction with impedance spectroscopy to fit and predict cell per- formance and degradation. This approach transformations. Using principles of non-equilibrium thermodynamics, we relate the cell voltage, ionic fluxes

Bazant, Martin Z.

156

To cite this document: Foletto, Marc and Douat, Claire and Fontane, Jrme and Joly, Laurent and Pitchford, Leanne and Puech, Vincent Influence of a plasma jet on the  

E-Print Network [OSTI]

voltages (5 kV) at frequencies of some tens of kHz. The plasma is launched in the helium jet surrounded panel) and with (lower panel) plasma, the plasma operating at 20 kHz and 5.5 kV and for different Non-equilibrium plasma jets operating at atmospheric pressure have attracted the attention of many

Mailhes, Corinne

157

THEORETICAL & APPLIED MECHANICS LETTERS 4, 022001 (2014) Unified gas-kinetic simulation of slider air bearing  

E-Print Network [OSTI]

, slider air-bearing, non-equilibrium The slider air bearing problem arises from the hard disk industry. The demand of higher recording density requires the spacing between the read/write head and the disk-assisting magnetic recording (HAMR) that introduces a heat source into the slider system. Both the nano-scale flying

Xu, Kun

158

Stochastic thermodynamics, fluctuation theorems, and molecular machines  

E-Print Network [OSTI]

Stochastic thermodynamics as reviewed here systematically provides a framework for extending the notions of classical thermodynamics like work, heat and entropy production to the level of individual trajectories of well-defined non-equilibrium ensembles. It applies whenever a non-equilibrium process is still coupled to one (or several) heat bath(s) of constant temperature. Paradigmatic systems are single colloidal particles in time-dependent laser traps, polymers in external flow, enzymes and molecular motors in single molecule assays, small biochemical networks and thermoelectric devices involving single electron transport. For such systems, a first-law like energy balance can be identified along fluctuating trajectories. Various integral and detailed fluctuation theorems, which are derived here in a unifying approach from one master theorem, constrain the probability distributions for work, heat and entropy production depending on the nature of the system and the choice of non-equilibrium conditions. For non-equilibrium steady states, particularly strong results hold like a generalized fluctuation-dissipation theorem involving entropy production. Ramifications and applications of these concepts include optimal driving between specified states in finite time, the role of measurement-based feedback processes and the relation between dissipation and irreversibility. Efficiency and, in particular, efficiency at maximum power, can be discussed systematically beyond the linear response regime for two classes of molecular machines, isothermal ones like molecular motors, and heat engines like thermoelectric devices, using a common framework based on a cycle decomposition of entropy production.

Udo Seifert

2012-05-18T23:59:59.000Z

159

Generating functional analysis of complex formation and dissociation in large protein interaction networks  

E-Print Network [OSTI]

proteins, using techniques from the non-equilibrium statistical mechanics of disordered many proteins are reaction partners from an ensemble of random graphs with an arbitrary degree distribution. WeGenerating functional analysis of complex formation and dissociation in large protein interaction

Coolen, ACC "Ton"

160

Towards breaking temperature equilibrium in multi-component Eulerian schemes  

SciTech Connect (OSTI)

We investigate the effects ofthermal equilibrium on hydrodynamic flows and describe models for breaking the assumption ofa single temperature for a mixture of components in a cell. A computational study comparing pressure-temperature equilibrium simulations of two dimensional implosions with explicit front tracking is described as well as implementation and J-D calculations for non-equilibrium temperature methods.

Grove, John W [Los Alamos National Laboratory; Masser, Thomas [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Free energy inference from partial work measurements Fluctuation Relations (FRs) are among the few general exact results  

E-Print Network [OSTI]

Free energy inference from partial work measurements Fluctuation Relations (FRs) are among the few application is free energy recovery from non-equilibrium pulling experiments in the single molecule field. We is a "partial" work measurement): it leads to a violation of FRs and to wrong free energy estimates

Potsdam, Universität

162

Conversion of Concentrated Solar Thermal Energy into Chemical Energy  

Science Journals Connector (OSTI)

When a concentrated solar beam is irradiated to the ceramics such as Ni-ferrite, the high-energy flux in the range of 1500–2500 kW/m2 is absorbed by an excess Frenkel defect formation. This non-equilibrium state ...

Yutaka Tamaura

2012-03-01T23:59:59.000Z

163

Florida Center for Advanced Aero-Propulsion (FCAAP) Annual Technical Symposium 2010 Three-dimensional Modeling of Microscale Plasma Actuators  

E-Print Network [OSTI]

holds a numerical advantage over these models in the treatment of high density plasma, where of dielectric barrier discharge (DBD) using the finite element based multiscale ionized gas (MIG) flow code to validate these predictions. At such small scales non-equilibrium interactions become important. Therefore

Roy, Subrata

164

CARBON NANOTUBE TRANSISTORS: AN EVALUATION  

E-Print Network [OSTI]

CARBON NANOTUBE TRANSISTORS: AN EVALUATION L.C. Castro, D.L. John, and D.L. Pulfrey Department A simple, non-equilibrium model is used to evaluate the likely DC performance of carbon nanotube field and transcon- ductance close to the low-quantum-capacitance limit. Keywords: Carbon nanotubes, field

Pulfrey, David L.

165

One Dimensional Autonomous Equations Can have only equilibrium attractors  

E-Print Network [OSTI]

One Dimensional Autonomous Equations ( )x f x Can have only equilibrium attractors: a bounded orbit approaches an equilibrium #12;Two Dimensional Autonomous Equations ( , ) ( , ) x f x y y g x y Can have non-equilibrium attractors: for example, periodic orbits #12;Two Dimensional Autonomous Equations ( , ) ( , ) x f x y y g x y

Saleska, Scott

166

Heat conduction in relativistic systems: alternatives and perspectives  

E-Print Network [OSTI]

The non-equilibrium thermodynamics of relativistic systems have a rich phenomenology. The simplest phenomenon in the class of dissipative processes is that of heat. This letter presents a brief summary of the efforts made to tackle the problem of relativistic heat conduction. In particular, we focus on the multi-fluid approach to relativistic dissipation.

C. S. Lopez-Monsalvo

2010-11-30T23:59:59.000Z

167

Water transport inside a single-walled carbon nanotube driven by temperature gradient  

E-Print Network [OSTI]

Water transport inside a single-walled carbon nanotube driven by temperature gradient J. Shiomi mass transport of a water cluster inside a single-walled carbon nanotube (SWNT) with the diameter of about 1.4 nm. The influence of the non-equilibrium thermal environment on the confined water cluster has

Maruyama, Shigeo

168

Entropy production in irreversible systems described by a Fokker-Planck equation Tnia Tom and Mrio J. de Oliveira  

E-Print Network [OSTI]

Entropy production in irreversible systems described by a Fokker-Planck equation Tânia Tomé and the entropy production in nonequilibrium interacting particle systems described by a Fokker-Planck equation equilibrium there will be no production of entropy. A non- equilibrium thermodynamic system in the stationary

de Oliveira, Mário José

169

Landscape Ecology vol. 6 no. 3 pp 147-159 (1992) SPB Academic Publishing bv, The Hague  

E-Print Network [OSTI]

Landscape Ecology vol. 6 no. 3 pp 147-159 (1992) SPB Academic Publishing bv, The Hague Landscape, Rheinsprung 9, CH-4051,Basel, Switzerland Keywords: landscape, metapopulation, reproductive systems, life history traits, non-equilibrium Abstract Distribution of genetic diversity in a landscape depends on both

170

Bias voltage dependence of the electron spin depolarization in quantum wires in the quantum Hall regime detected by the resistively detected NMR  

SciTech Connect (OSTI)

We performed the resistively-detected nuclear magnetic resonance (RDNMR) to study the electron spin polarization in the non-equilibrium quantum Hall regime. By measuring the Knight shift, we derive source-drain bias voltage dependence of the electron spin polarization in quantum wires. The electron spin polarization shows minimum value around the threshold voltage of the dynamic nuclear polarization.

Chida, K.; Yamauchi, Y.; Arakawa, T.; Kobayashi, K.; Ono, T. [Institute for Chemical Research, Kyoto University, Kyoto (Japan); Hashisaka, M. [Institute for Chemical Research, Kyoto University, Kyoto, Japan and Department of Physics, Tokyo Institute of Technology, Tokyo (Japan); Nakamura, S. [Institute for Chemical Research, Kyoto University, Kyoto, Japan and AIST, Tsukuba (Japan); Machida, T. [IIS and INQIE, University of Tokyo (Japan)

2013-12-04T23:59:59.000Z

171

CPFFS Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 20 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

172

LFS Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Dated 5-20-13 Dated 5-20-13 Subcontract No. 241314 Page 1 of 19 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012 - Deviation) ........................................................................................ 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 4 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

173

EFS Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 26 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2 AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Apr 2013) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

174

R&D Ex A (Rev. 3.1, 4/9/13) Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 31 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

175

EFS Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 39 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2 AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Apr 2013) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

176

AES Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 18 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

177

TM Exhibit A General Conditions (Rev. 7.3, 9-27-13)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3, 9/27/13) Exhibit A General Conditions 3, 9/27/13) Exhibit A General Conditions Page 1 of 20 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011) ............................................................................................

178

CONST Ex A (Rev. 5.1, 4/9/13) Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 39 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2 AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Apr 2013) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

179

SFS Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 16 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

180

IDIQ BS Ex A (Rev. 3.2, 6/14/13) Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 19 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) ......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ....... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................ 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) .................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011) ........................................................................................... 4 GC-6 ORDER OF PRECEDENCE (Jun 2009) ................................................................................... 5

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Time and Materials Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 20 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

182

D-B CONST Ex A (Rev. 4.1, 4/9/13) Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 40 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2 AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Apr 2013) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

183

CPFFS Exhibit A General Conditions (Rev. 8.3, 9-27-13)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3, 9/27/13) Exhibit A General Conditions 3, 9/27/13) Exhibit A General Conditions Page 1 of 21 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011) ............................................................................................

184

Electronic structure, stacking energy, partial charge, and hydrogen bonding in four periodic B-DNA models  

Science Journals Connector (OSTI)

We present a theoretical study of the electronic structure of four periodic B-DNA models labeled (AT)10, (GC)10, (AT)5(GC)5, and (AT?GC)5 where A denotes adenine, T denotes thymine, G denotes guanine, and C denotes cytosine. Each model has ten base pairs with Na counterions to neutralize the negative phosphate group in the backbone. The (AT)5(GC)5 and (AT?GC)5 models contain two and five AT-GC bilayers, respectively. When compared against the average of the two pure models, we estimate the AT-GC bilayer interaction energy to be 19.015 Kcal/mol, which is comparable to the hydrogen bonding energy between base pairs obtained from the literature. Our investigation shows that the stacking of base pairs plays a vital role in the electronic structure, relative stability, bonding, and distribution of partial charges in the DNA models. All four models show a highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) gap ranging from 2.14 to 3.12 eV with HOMO states residing on the PO4 + Na functional group and LUMO states originating from the bases. Our calculation implies that the electrical conductance of a DNA molecule should increase with increased base-pair mixing. Interatomic bonding effects in these models are investigated in detail by analyzing the distributions of the calculated bond order values for every pair of atoms in the four models including hydrogen bonding. The counterions significantly affect the gap width, the conductivity, and the distribution of partial charge on the DNA backbone. We also evaluate quantitatively the surface partial charge density on each functional group of the DNA models.

Lokendra Poudel; Paul Rulis; Lei Liang; W. Y. Ching

2014-08-07T23:59:59.000Z

185

IDIQ BS Ex A (Rev. 3.1, 4/9/13) Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 31 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) ......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ....... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................ 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) .................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011) ........................................................................................... 4 GC-6 ORDER OF PRECEDENCE (Jun 2009) ................................................................................... 5

186

SFS Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 29 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

187

Abstract for Gouranga C. Nayak  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Gouranga C. Nayak Gouranga C. Nayak Gluon Propagator and Magnetic Screening Mass at One Loop Level in Non-Equilibrium QCD Using closed-time path integral formalism I will show for the first time that the magnetic screening mass at one loop level in QED and QCD is non-zero as long as the distribution function is anisotropic in momentum space. For isotropic distribution function such as the thermal distribution function the magnetic screening mass at one loop level is zero which is consistent with finite temperature field theory results. I will also show that the same non-zero magnetic screening results is also obtained by using transport equation approach. I will present a resummed (at one loop level of self energy) gluon propagator in any arbitary covariant gauge in non-equilibrium in any arbitary moving frame which can be used in the

188

Generalized Elastic Model: thermal vs non-thermal initial conditions. Universal scaling, roughening, ageing and ergodicity  

E-Print Network [OSTI]

We study correlation properties of the generalized elastic model which accounts for the dynamics of polymers, membranes, surfaces and fluctuating interfaces, among others. We develop a theoretical framework which leads to the emergence of universal scaling laws for systems starting from thermal (equilibrium) or non-thermal (non-equilibrium) initial conditions. Our analysis incorporates and broadens previous results such as observables' double scaling regimes, (super)roughening and anomalous diffusion, and furnishes a new scaling behavior for correlation functions at small times (long distances). We discuss ageing and ergodic properties of the generalized elastic model in non-equilibrium conditions, providing a comparison with the situation occurring in continuous time random walk. Our analysis also allows to assess which observable is able to distinguish whether the system is in or far from equilibrium conditions in an experimental set-up.

Taloni, Alessandro; Klafter, Joseph; 10.1209/0295-5075/97/30001

2012-01-01T23:59:59.000Z

189

The Effect of Disorder in Superfluid Double Layer Graphene  

E-Print Network [OSTI]

We investigate the superfluid properties of disordered double layer graphene systems using the non-equilibrium Green's function (NEGF) formalism. The complexity of such a structure makes it imperative to study the effects of lattice vacancies which will inevitably arise during fabrication. We present and compare room temperature performance characteristics for both ideal and disordered bilayer graphene systems in an effort to illustrate the behavior of a Bose-Einstein Condensate in the presence of lattice defects under non-equilibrium conditions. We find that lattice vacancies spread throughout the top layer past the coherence length have a reduced effect compared to the ideal case. However, vacancies concentrated near the metal contacts within the coherence length significantly alter the interlayer superfluid transport properties.

Brian Dellabetta; Matthew J. Gilbert

2011-04-12T23:59:59.000Z

190

Development of High-efficiency Thermoelectric Materials for Vehicle Waste Heat Utililization  

SciTech Connect (OSTI)

The goals of this . CRADA are: 1) Investigation of atomistic structure and nucleation of nanoprecipitates in (PbTe){sub I-x}(AgSbTe2){sub x} (LAST) system; and 2) Development of non-equilibrium synthesis of thermoelectric materials for waste heat recovery. We have made significant accomplishment in both areas. We studied the structure of LAST materials using high resolution imaging, nanoelectron diffraction, energy dispersive spectrum, arid electron energy loss spectrum, and observed a range of nanoparticles The results, published in J. of Applied Physics, provide quantitative structure information about nanoparticles, that is essential for the understanding of the origin of the high thermoelectric performance in this class of materials. We coordinated non-equilibrium synthesis and characterization of thermoelectric materials for waste heat recovery application. Our results, published in J. of Electronic Materials, show enhanced thermoelectric figure of merit and robust mechanical properties in bulk . filled skutterudites.

Li, Qiang

2009-04-30T23:59:59.000Z

191

Subpicosecond time-resolved Raman studies of nonequilibrium excitations in wurtzite GaN  

SciTech Connect (OSTI)

Non-equilibrium electron distributions as well as phonon dynamics in wurtzite GaN have been measured by subpicosecond time-resolved Raman spectroscopy. The experimental results have demonstrated that for electron densities n {ge} 5 {times} 10{sup 17} cm{sup {minus}3}, the non-equilibrium electron distributions in wurtzite GaN can be very well described by Fermi-Dirac distribution functions with the temperature of electrons substantially higher than that of the lattice. The population relaxation time of longitudinal optical phonons was directly measured to be {tau} {approx_equal} 5 {+-} 1 ps at T = 25 K. The experimental results on the temperature dependence of the lifetime of longitudinal optical phonons suggest that the primary decay channels for these phonons are the decay into (1) one transverse optical phonon and one high energy, longitudinal or transverse acoustical phonons; and (2) one transverse optical phonon and one E{sub 2} phonon.

Tsen, K.T.; Ferry, D.K. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics and Astronomy; Joshi, R.P. [Old Dominion Univ., Norfolk, VA (United States). Dept. of Electrical Engineering; Botchkarev, A.; Sverdlov, B.; Salvador, A.; Morkoc, H. [Univ. of Illinois, Urbana, IL (United States). Coordinated Science Lab.

1997-12-31T23:59:59.000Z

192

A Realist Interpretation of the Quantum Measurement Problem  

E-Print Network [OSTI]

A new, realist interpretation of the quantum measurement processes is given. In this scenario a quantum measurement is a non-equilibrium phase transition in a ``resonant cavity'' formed by the entire physical universe including all its material and energy content. Both the amplitude and the phase of the quantum mechanical wavefunction acquire substantial meaning in this picture, and the probabilistic element is removed from the foundations of quantum mechanics, its apparent presence in the quantum measurement process is viewed as a result of the sensitive dependence on initial/boundary conditions of the non-equilibrium phase transitions in a many degree-of-freedom system. The implications of adopting this realist ontology to the clarification and resolution of lingering issues in the foundations of quantum mechanics, such as wave-particle duality, Heisenberg's uncertainty relation, Schrodinger's Cat paradox, first and higher order coherence of photons and atoms, virtual particles, the existence of commutation relations and quantized behavior, etc., are also presented.

Xiaolei Zhang

2006-02-27T23:59:59.000Z

193

Irreversible Thermodynamics of the Universe: Constraints from Planck Data  

E-Print Network [OSTI]

The present work deals with irreversible Universal thermodynamics. The homogenous and isotropic flat model of the universe is chosen as open thermodynamical system and non-equilibrium thermodynamics comes into picture due to the mechanism of particle creation. For simplicity, entropy flow is considered only due to heat conduction. Further, due to Maxwell-Cattaneo modified Fourier law for non-equilibrium phenomenon, the temperature satisfies damped wave equation instead of heat conduction equation. Validity of generalized second law of thermodynamics (GSLT) has been investigated for Universe bounded by apparent or event horizon with cosmic substrutum as perfect fluid with constant or variable equation of state or interacting dark species. Finally, we have used three Planck data sets to constrain the thermal conductivity \\lambda and the coupling parameter b^2. These constraints must be satisfied in order for GSLT to hold for Universe bounded by apparent or event horizons.

Subhajit Saha; Atreyee Biswas; Subenoy Chakraborty

2014-04-04T23:59:59.000Z

194

Influence of Electron-Impact Multiple Ionization on Equilibrium and Dynamic Charge State Distributions: A Case Study Using Iron  

E-Print Network [OSTI]

We describe the influence of electron-impact multiple ionization (EIMI) on the ionization balance of collisionally ionized plasmas. We are unaware of any previous ionization balance calculations that have included EIMI, which is usually assumed to be unimportant. Here, we incorporate EIMI cross-section data into calculations of both equilibrium and non-equilibrium charge-state distributions (CSDs). For equilibrium CSDs, we find that EIMI has only a small effect and can usually be ignored. However, for non-equilibrium plasmas the influence of EIMI can be important. In particular, we find that for plasmas in which the temperature oscillates there are significant differences in the CSD when including versus neglecting EIMI. These results have implications for modeling and spectroscopy of impulsively heated plasmas, such as nanoflare heating of the solar corona.

Hahn, Michael

2014-01-01T23:59:59.000Z

195

The nonequilibrium Ehrenfest gas: a chaotic model with flat obstacles?  

E-Print Network [OSTI]

It is known that the non-equilibrium version of the Lorentz gas (a billiard with dispersing obstacles, electric field and Gaussian thermostat) is hyperbolic if the field is small. Differently the hyperbolicity of the non-equilibrium Ehrenfest gas constitutes an open problem, since its obstacles are rhombi and the techniques so far developed rely on the dispersing nature of the obstacles. We have developed analytical and numerical investigations which support the idea that this model of transport of matter has both chaotic (positive Lyapunov exponent) and non-chaotic steady states with a quite peculiar sensitive dependence on the field and on the geometry, not observed before. The associated transport behaviour is correspondingly highly irregular, with features whose understanding is of both theoretical and technological interest.

Carlo Bianca; Lamberto Rondoni

2008-11-25T23:59:59.000Z

196

A proposal for testing subcritical vacuum pair production with high power lasers  

E-Print Network [OSTI]

We present a proposal for testing the prediction of non-equilibrium quantum field theory below the Schwinger limit. The proposed experiments should be able to detect a measurable number of gamma rays resulting from the annihilation of pairs in the focal spot of two opposing high intensity laser beams. We discuss the dependence of the expected number of gamma rays with the laser parameters and compare with the estimated background level of gamma hits for realistic laser conditions.

G. Gregori; D. B. Blaschke; P. P. Rajeev; H. Chen; R. J. Clarke; T. Huffman; C. D. Murphy; A. V. Prozorkevich; C. D. Roberts; G. Röpke; S. M. Schmidt; S. A. Smolyansky; S. Wilks; R. Bingham

2010-05-18T23:59:59.000Z

197

Feeling de Sitter  

E-Print Network [OSTI]

We address the following question: To what extent can a quantum field tell if it has been placed in de Sitter space? Our approach is to use the techniques of non-equilibrium quantum field theory to compute the time evolution of a state which starts off in flat space for (conformal) times $\\etaanalysis suggests that the nature of the equilibration process in this system is similar to that in more familiar systems.

Albrecht, Andreas; Richard, Benoit J

2014-01-01T23:59:59.000Z

198

Feeling de Sitter  

E-Print Network [OSTI]

We address the following question: To what extent can a quantum field tell if it has been placed in de Sitter space? Our approach is to use the techniques of non-equilibrium quantum field theory to compute the time evolution of a state which starts off in flat space for (conformal) times $\\etaanalysis suggests that the nature of the equilibration process in this system is similar to that in more familiar systems.

Andreas Albrecht; R. Holman; Benoit J. Richard

2014-10-09T23:59:59.000Z

199

INVARIANT KAPPA DISTRIBUTION IN SPACE PLASMAS OUT OF EQUILIBRIUM  

SciTech Connect (OSTI)

Recent advances in Space Physics theory have shown the connection between non-extensive Statistical Mechanics and space plasmas by providing a theoretical basis for the empirically derived kappa distributions commonly used to describe the phase-space distribution functions of these systems. The non-equilibrium temperature and the kappa index that govern these distributions are the two independent controlling parameters of non-equilibrium systems. The significance of the kappa index is primarily given by its role in identifying the non-equilibrium stationary states and measuring their 'thermodynamic distance' from thermal equilibrium, while its physical meaning is connected to the correlation between the system's particles. The classical, single stationary state at equilibrium is generalized into a whole set of different non-equilibrium stationary states labeled by the kappa index. This paper addresses certain crucial issues about the physical meaning and role of the kappa index in identifying stationary states. The origin of the emerged inconsistencies is that the kappa index is not an invariant physical quantity, but instead depends on the degrees of freedom of the system's particles. This leads in several misleading conclusions, such as (1) only large kappa index, practically infinite, can characterize the many-particle kappa distribution, and (2) the correlation between particles depends on the total number of the system's particles. Here we show that a modified kappa index, invariant for any number of degrees of freedom, can be naturally defined. Then, we develop and examine the relevant corrected formulation of many-particle multidimensional kappa distribution, and discuss the physical meaning of the invariant kappa index.

Livadiotis, G.; McComas, D. J., E-mail: glivadiotis@swri.edu [Southwest Research Institute, San Antonio, TX-78238 (United States)

2011-11-10T23:59:59.000Z

200

Modeling for Anaerobic Fixed-Bed Biofilm Reactors  

SciTech Connect (OSTI)

The specific objectives of this research were: 1. to develop an equilibrium model for chemical aspects of anaerobic reactors; 2. to modify the equilibrium model for non-equilibrium conditions; 3. to incorporate the existing biofilm models into the models above to study the biological and chemical behavior of the fixed-film anaerobic reactors; 4. to experimentally verify the validity of these models; 5. to investigate the biomass-holding ability of difference packing materials for establishing reactor design criteria.

Liu, B. Y. M.; Pfeffer, J. T.

1989-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Exchange Fluctuation Theorem for correlated quantum systems  

E-Print Network [OSTI]

We extend the Exchange Fluctuation Theorem for energy exchange between thermal quantum systems beyond the assumption of molecular chaos, and describe the non-equilibrium exchange dynamics of correlated quantum states. The relation quantifies how the tendency for systems to equilibrate is modified in high-correlation environments. Our results elucidate the role of measurement disturbance for such scenarios. We show a simple application by finding a semi-classical maximum work theorem in the presence of correlations.

Sania Jevtic; David Jennings; Terry Rudolph; Yuji Hirono; Shojun Nakayama; Mio Murao

2014-12-04T23:59:59.000Z

202

Roles of Dry Friction in Fluctuating Motion of Adiabatic Piston  

E-Print Network [OSTI]

The motion of an adiabatic piston under dry friction is investigated to clarify the roles of dry friction in non-equilibrium steady states. We clarify that dry friction can reverse the direction of the piston motion and causes a discontinuity or a cusp-like singularity for velocity distribution functions of the piston. We also show that the heat fluctuation relation is modified under dry friction.

Tomohiko G. Sano; Hisao Hayakawa

2014-03-08T23:59:59.000Z

203

Signatures of new phenomena in ultrarelativistic nuclear collisions  

SciTech Connect (OSTI)

Three classes of observables are discussed which may shed light on the properties of the quark-gluon plasma formed in ultrarelativistic nuclear collisions. They are: (1) thermometers: the penetrating probes ..mu../sup +/..mu../sup -/, ..gamma.., c, (2) barometers: transverse flow via

, and (3) seismometers: fluctuations of dN/dy and dE perpendicular/dy. The need for reliable estimates of the background due to the non-equilibrium processes is emphasized. 49 references.

Gyulassy, M.

1983-11-01T23:59:59.000Z

204

Independent electrons model for open quantum systems: Landauer-Buettiker formula and strict positivity of the entropy production  

E-Print Network [OSTI]

A general argument leading from the formula for currents through an open noninteracting mesoscopic system given by the theory of non-equilibrium steady states (NESS) to the Landauer-Buettiker formula is pointed out. Time reversal symmetry is not assumed. As a consequence it follows that, as far as the system has a nontrivial scattering theory and the reservoirs have different temperatures and/or chemical potentials, the entropy production is strictly positive.

G. Nenciu

2006-10-26T23:59:59.000Z

205

Ion pump activity generates fluctuating electrostatic forces in biomembranes  

E-Print Network [OSTI]

We study the non-equilibrium dynamics of lipid membranes with proteins that actively pump ions across the membrane. We find that the activity leads to a fluctuating force distribution due to electrostatic interactions arising from variation in dielectric constant across the membrane. By applying a multipole expansion we find effects on both the tension and bending rigidity dominated parts of the membranes fluctuation spectrum. We discuss how our model compares with previous studies of force-multipole models.

B. Loubet; M. A. Lomholt

2011-09-19T23:59:59.000Z

206

Molecule-based approach for computing chemical-reaction rates in upper atmosphere hypersonic flows.  

SciTech Connect (OSTI)

This report summarizes the work completed during FY2009 for the LDRD project 09-1332 'Molecule-Based Approach for Computing Chemical-Reaction Rates in Upper-Atmosphere Hypersonic Flows'. The goal of this project was to apply a recently proposed approach for the Direct Simulation Monte Carlo (DSMC) method to calculate chemical-reaction rates for high-temperature atmospheric species. The new DSMC model reproduces measured equilibrium reaction rates without using any macroscopic reaction-rate information. Since it uses only molecular properties, the new model is inherently able to predict reaction rates for arbitrary nonequilibrium conditions. DSMC non-equilibrium reaction rates are compared to Park's phenomenological non-equilibrium reaction-rate model, the predominant model for hypersonic-flow-field calculations. For near-equilibrium conditions, Park's model is in good agreement with the DSMC-calculated reaction rates. For far-from-equilibrium conditions, corresponding to a typical shock layer, the difference between the two models can exceed 10 orders of magnitude. The DSMC predictions are also found to be in very good agreement with measured and calculated non-equilibrium reaction rates. Extensions of the model to reactions typically found in combustion flows and ionizing reactions are also found to be in very good agreement with available measurements, offering strong evidence that this is a viable and reliable technique to predict chemical reaction rates.

Gallis, Michail A.; Bond, Ryan Bomar; Torczynski, John Robert

2009-08-01T23:59:59.000Z

207

Research | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Research Research Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Basic Research Needs Grand Challenges Science Highlights News & Events Publications Contact BES Home Research Print Text Size: A A A RSS Feeds FeedbackShare Page The 46 EFRC awards span the full range of energy research challenges described in the BES Basic Research Needs (BRN) series of workshop reports while also addressing one or more of the science grand challenges described in the BESAC report, Directing Matter and Energy: Five Challenge for Science and the Imagination (see below). Many of the EFRCs address multiple energy challenges that are linked by common scientific themes, such as interfacial chemistry for solar energy conversion and electrical energy storage or rational design of materials for multiple potential energy

208

EFRC: Administration and Operation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mark Pederson PhD Computation and Theoretical Chemistry Office of Basic Energy Sciences Office of Science, U.S. Department of Energy Computing and Storage Requirements for Basic Energy Sciences An ASCR / BES / NERSC Workshop February 9-10, 2010 9AM OFFICE OF SCIENCE OFFICE OF SCIENCE Primary: Near Future Needs of Capacity Computing? BES has approximately 150 users requesting 50K to 4M processor hours (PU) per year. BES users use approximately 80-100M PU per year through the NERSC allocation process NERSC users span the BES core research areas, the energy frontier research centers and the "Basic Research Needs (BRN)" workshops. Role/Needs of Capacity vs Capability? OFFICE OF SCIENCE Energy and Science Grand Challenges http://www.sc.doe.gov/bes/reports/list.html

209

CI-ON Ex A (Rev. 0.2, 6/14/13) Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 12 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-A1 COMMERCIAL ITEMS (Mar 2012)............................................................................................ 2 GC-1B DEFINITIONS (Mar 2012) ......................................................................................................... 4 GC-2B CORRESPONDENCE AND SUBCONTRACT INTERPRETATION (Jan 2010) ....................... 4 GC-5 NOTICE TO PROCEED (Jul 2011) ........................................................................................... 4 GC-6A ORDER OF PRECEDENCE (Jan 2010) ................................................................................... 5 GC-11 NEW MEXICO GROSS RECEIPTS TAX (Jun 2009)................................................................ 5

210

CI-ON Ex A (Rev. 0.1, 4/9/13) Exhibit A General Conditions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 24 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-A1 COMMERCIAL ITEMS (Mar 2012)............................................................................................ 2 GC-1B DEFINITIONS (Mar 2012) ......................................................................................................... 4 GC-2B CORRESPONDENCE AND SUBCONTRACT INTERPRETATION (Jan 2010) ....................... 4 GC-5 NOTICE TO PROCEED (Jul 2011) ........................................................................................... 4 GC-6A ORDER OF PRECEDENCE (Jan 2010) ................................................................................... 5 GC-11 NEW MEXICO GROSS RECEIPTS TAX (Jun 2009)................................................................ 5

211

CI-ON Exhibit A General Conditions (Rev 0.3, 9-27-13)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3, 9/27/13) Exhibit A General Conditions 3, 9/27/13) Exhibit A General Conditions Page 1 of 12 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-A1 COMMERCIAL ITEMS (Mar 2012) ........................................................................................... 2 GC-1B DEFINITIONS (Mar 2012) ......................................................................................................... 4 GC-2B CORRESPONDENCE AND SUBCONTRACT INTERPRETATION (Jan 2010) ....................... 4 GC-5 NOTICE TO PROCEED (Jul 2011) ........................................................................................... 4 GC-6A ORDER OF PRECEDENCE (Jan 2010) ................................................................................... 5 GC-11 NEW MEXICO GROSS RECEIPTS TAX (Jun 2009) ................................................................ 5

212

Photoinduced aging and viscosity evolution in Se-rich Ge-Se glasses  

SciTech Connect (OSTI)

We propose here to investigate the non-equilibrium viscosity of Ge-Se glasses under and after light irradiation. Ge{sub 10}Se{sub 90} and Ge{sub 20}Se{sub 80} fibers have been aged in the dark and under ambient light, over months. During aging, both the relaxation of enthalpy and the viscosity have been investigated. The viscosity was measured by shear relaxation-recovery tests allowing the measurement of non-equilibrium viscosity. When Ge{sub 10}Se{sub 90} glass fibers are aged under irradiation, a relatively fast fictive temperature decrease is observed. Concomitantly, during aging under irradiation, the non-equilibrium viscosity increases and reaches an equilibrium after two months of aging. This viscosity increase is also observed in Ge{sub 20}Se{sub 80} fibers. Nevertheless, this equilibrium viscosity is far below the viscosity expected at the configurational equilibrium. As soon as the irradiation ceases, the viscosity increases almost instantaneously by about one order of magnitude. Then, if the fibers are kept in the dark, their viscosity slowly increases over months. The analysis of the shear relaxation functions shows that the aging is thermorheologically simple. On the other side, there is no simple relaxation between the shear relaxation functions measured under irradiation and those measured in the dark. These results clearly suggest that a very specific photoinduced aging process occurs under irradiation. This aging is due to photorelaxation. Nevertheless, the viscosity changes are not solely correlated to photoaging and photorelaxation. A scenario is proposed to explain all the observed viscosity evolutions under and after irradiation, on the basis of photoinduced transient defects.

Gueguen, Yann; Sangleboeuf, Jean-Christophe; Rouxel, Tanguy [LARMAUR ERL CNRS 6274, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France)] [LARMAUR ERL CNRS 6274, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); King, Ellyn A.; Lucas, Pierre [Department of Materials Science and Engineering, University of Arizona, 4715 E. Fort Lowell Road, Tucson, Arizona 85712 (United States)] [Department of Materials Science and Engineering, University of Arizona, 4715 E. Fort Lowell Road, Tucson, Arizona 85712 (United States); Keryvin, Vincent [LIMATB EA 4250, Université de Bretagne Sud, Rue de Saint Maudé, 56321 Lorient Cedex (France)] [LIMATB EA 4250, Université de Bretagne Sud, Rue de Saint Maudé, 56321 Lorient Cedex (France); Bureau, Bruno [Equipe Verres et Céramiques, UMR-CNRS 6226 Sciences Chimiques de Rennes, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France)] [Equipe Verres et Céramiques, UMR-CNRS 6226 Sciences Chimiques de Rennes, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France)

2013-08-21T23:59:59.000Z

213

NERC | U.S. DOE Office of Science (SC)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NERC NERC Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights News & Events Publications Contact BES Home Centers NERC Print Text Size: A A A RSS Feeds FeedbackShare Page Non-equilibrium Energy Research Center (NERC) Director(s): Bartosz A. Grzybowski Lead Institution: Northwestern University Mission: To understand self-organization in dissipative, far-from-equilibrium systems and to use this knowledge to synthesize adaptive, reconfigurable materials for energy storage and transduction. Research Topics: catalysis (homogeneous), catalysis (heterogeneous), thermal conductivity, thermoelectric, bio-inspired, energy storage (including batteries and capacitors), superconductivity, mechanical behavior, charge transport, materials and chemistry by design, synthesis (novel materials), synthesis

214

DOE Final Technical Report for Grant Number DE-FG03-90ER14148  

SciTech Connect (OSTI)

OAK-B135 Thermal convection was studied in a horizontal layer of a binary fluid mixture of ethanol and water confined in a variety of cell geometries. In these mixtures, convection takes the form of traveling waves, thus providing a model for studying traveling-wave (TW) phenomena in non-equilibrium systems. A number of questions were addressed, including the evolution of initially chaotic states, the role of TW domains textures and convection-cell geometry in determining patterns, and the competition of TW and hexagonal patterns when non-Boussinesq effects are important.

Clifford M. Surko

2004-03-01T23:59:59.000Z

215

Directed transport in equilibrium : analysis of the dimer model with inertial terms  

E-Print Network [OSTI]

We have previously shown an analysis of our dimer model in the over-damped regime to show directed transport in equilibrium. Here we analyze the full model with inertial terms present to establish the same result. First we derive the Fokker-Planck equation for the system following a Galilean transformation to show that a uniformly translating equilibrium distribution is possible. Then, we find out the velocity selection for the centre of mass motion using that distribution on our model. We suggest generalization of our calculations for soft collision potentials and indicate to interesting situation with possibility of oscillatory non-equilibrium state within equilibrium.

A. Bhattacharyay

2011-08-15T23:59:59.000Z

216

Experimental Investigation Of Atmospheric Pressure Surface Wave Discharges  

SciTech Connect (OSTI)

Microwave atmospheric pressure discharge in neon sustained by surface waves in a dielectric tube is considered. The plasma column length was measured versus absorbed microwave power for different discharge conditions. This gives a view on the wave propagation characteristics. The predicted dependence of discharge length on the total flux of wave power based on the modified model of non-equilibrium plasma is compared with experimental values. Moreover, we present results of spectroscopic investigations of the electron density. The electron density was determined using the method based on the Stark broadening of H{beta} spectral line. The spectroscopic results we shall use developing of a model of propagation of surface wave.

Czylkowski, D.; Jasinski, M.; Nowakowska, H.; Zakrzewski, Z. [The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk (Poland)

2006-01-15T23:59:59.000Z

217

Novel photonic crystal cavities and related structures.  

SciTech Connect (OSTI)

The key accomplishment of this project is to achieve a much more in-depth understanding of the thermal emission physics of metallic photonic crystal through theoretical modeling and experimental measurements. An improved transfer matrix technique was developed to enable incorporation of complex dielectric function. Together with microscopic theory describing emitter radiative and non-radiative relaxation dynamics, a non-equilibrium thermal emission model is developed. Finally, experimental methodology was developed to measure absolute emissivity of photonic crystal at high temperatures with accuracy of +/-2%. Accurate emissivity measurements allow us to validate the procedure to treat the effect of the photonic crystal substrate.

Luk, Ting Shan

2007-11-01T23:59:59.000Z

218

Nanoscale Graphene Disk: A Natural Functionally Graded Material --The Thermal Conductivity of Nanoscale Graphene Disk by Molecular Dynamics Simulation  

E-Print Network [OSTI]

In this letter, we investigate numerically (by non-equilibrium molecular dynamics) and analytically the thermal conductivity of nanoscale graphene disks (NGDs), and discussed the possibility to realize FGM with only one material, NGDs. We found that the NGD has a graded thermal conductivity and can be used as FGM in a large temperature range. Moreover, we show the dependent of NGDs' thermal conductivity on radius and temperature. Our study may inspire experimentalists to develop NGD based FGMs and help heat removal of hot spots on chips by graphene.

Yang, Nuo; Ma, Dengke; Lu, Tingyu; Li, Baowen

2014-01-01T23:59:59.000Z

219

Plastic flow in solids with interfaces  

E-Print Network [OSTI]

A non-equilibrium theory of isothermal and diffusionless evolution of incoherent interfaces within a plastically deforming solid is developed. The irreversible dynamics of the interface are driven by its normal motion, incoherency (slip and misorientation), and an intrinsic plastic flow; and purely by plastic deformation in the bulk away from the interface. Using the continuum theory for defect distribution (in bulk and over the interface) we formulate a general kinematical framework, derive relevant balance laws and jump conditions, and prescribe a thermodynamically consistent constitutive/kinetic structure for interface evolution.

Anurag Gupta; David Steigmann

2011-11-25T23:59:59.000Z

220

Entropy Meters and the Entropy of Non-extensive Systems  

E-Print Network [OSTI]

In our derivation of the second law of thermodynamics from the relation of adiabatic accessibility of equilibrium states we stressed the importance of being able to scale a system's size without changing its intrinsic properties. This leaves open the question of defining the entropy of macroscopic, but unscalable systems, such as gravitating bodies or systems where surface effects are important. We show here how the problem can be overcome, in principle, with the aid of an `entropy meter'. An entropy meter can also be used to determine entropy functions for non-equilibrium states and mesoscopic systems.

Elliott H. Lieb; Jakob Yngvason

2014-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Microparticles deep in the plasma sheath: Coulomb 'explosion'  

SciTech Connect (OSTI)

A cloud of microparticles was trapped deep in the sheath of a radio-frequency (rf) discharge, very close to the lower (grounded) electrode of the plasma chamber. This was achieved by employing a specifically designed rf-driven segment integrated in the lower electrode, which provided an additional confinement compressing the cloud to a very high density. After switching the rf-driven segment off, the cloud 'exploded' due to mutual interparticle repulsion. By combining a simple theoretical model with different numerical simulation methods, some basic properties of complex plasmas in this highly non-equilibrium regime were determined.

Antonova, T.; Du, C.-R.; Ivlev, A. V.; Hou, L.-J.; Thomas, H. M.; Morfill, G. E. [Max-Planck-Institut fuer Extraterrestrische Physik, D-85741 Garching (Germany); Annaratone, B. M. [PIIM, UMR6633 CNRS/Universite de Provence, Campus St. Jerome F-13397, Marseille (France); Kompaneets, R. [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia)

2012-09-15T23:59:59.000Z

222

Emission and Absorption Spectroscopy of Carbon Arc Plasma during Formation of Carbon Magnetic Encapsulates  

SciTech Connect (OSTI)

Plasma diagnostics of carbon arc discharge under conditions of carbon magnetic encapsulates formation was performed by emission and absorption spectroscopy. Content of C{sub 2} and Fe species, rotational temperatures of excited (d {sup 3} product {sub g}) and non-excited (a {sup 3} product {sub u}) states, and excitation temperatures of a {sup 5}F and a {sup 3}F levels relatively to the a {sup 5}D level of Fe atoms were determined. The results pointed to a non-equilibrium state of carbon arc plasma under prevailing discharge conditions.

Lange, H.; Labedz, O.; Huczko, A.; Bystrzejewski, M. [Faculty of Chemistry, Warsaw University, Pasteur str. 1,02-093 Warsaw (Poland)

2011-11-29T23:59:59.000Z

223

Mid infrared optical properties of Ge/Si quantum dots with different doping level  

SciTech Connect (OSTI)

Optical characterization of the Ge/Si quantum dots using equilibrium and photo-induced absorption spectroscopy in the mid-infrared spectral range was performed in this work. Equilibrium absorption spectra were measured in structures with various doping levels for different light polarizations. Photo-induced absorption spectra measured in undoped structure under interband optical excitation of non-equilibrium charge carriers demonstrate the same features as doped sample in equilibrium conditions. Hole energy spectrum was determined from the analysis of experimental data.

Sofronov, A. N.; Firsov, D. A.; Vorobjev, L. E.; Shalygin, V. A.; Panevin, V. Yu.; Vinnichenko, M. Ya. [St. Petersburg State Polytechnic University, Polytechnicheskaya str. 29, St. Petersburg (Russian Federation); Tonkikh, A. A. [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); Danilov, S. N. [University of Regensburg, Regensburg (Germany)

2013-12-04T23:59:59.000Z

224

Spintronic transport of a non-magnetic molecule between magnetic electrodes  

SciTech Connect (OSTI)

The spintronic transport properties of a junction system composed of a non-magnetic molecule sandwiched between ferromagnetic metal electrodes are investigated theoretically using a non-equilibrium Green's function method based on density functional theory. It is revealed that in such a system, the molecular magnetic properties induced by hybridization with the magnetic electrodes play a crucial role. Alignment of the induced molecular spin-split levels is strongly related to the spin injection and tunneling magneto-resistance effects. It is found that in the system with weaker molecule-electrode interaction, stronger spintronic effects of the spin injection and tunneling magneto-resistance are observed.

Kondo, Hisashi, E-mail: kondo@tokyo.rist.or.jp [Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan)] [Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan); Ohno, Takahisa, E-mail: OHNO.Takahisa@nims.go.jp [Computational Materials Science Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan) [Computational Materials Science Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan)

2013-12-02T23:59:59.000Z

225

Quantum thermal machines with single nonequilibrium environments  

E-Print Network [OSTI]

We propose a scheme for a quantum thermal machine made by atoms interacting with a single non-equilibrium electromagnetic field. The field is produced by a simple configuration of macroscopic objects held at thermal equilibrium at different temperatures. We show that these machines can deliver all thermodynamic tasks (cooling, heating and population inversion), and this by establishing quantum coherence with the body on which they act. Remarkably, this system allows to reach efficiencies at maximum power very close to the Carnot limit, much more than in existing models. Our findings offer a new paradigm for efficient quantum energy flux management, and can be relevant for both experimental and technological purposes.

Bruno Leggio; Bruno Bellomo; Mauro Antezza

2015-01-08T23:59:59.000Z

226

Ultrafast population dynamics in electrically modulated terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

The ultrafast population dynamics in electrically modulated three-well terahertz quantum cascade lasers (QCLs) is studied by using the self-consistent Bloch–Poisson equations. In the modulation process, the non-equilibrium oscillations of the population inversion are found before the population equilibrium recovers. The equilibrium formation time increases nonlinearly with the period number. This phenomenon stems from the non-uniform distribution of the electric potential. In different periods, different responses to the electrical modulation are also explored. An in-depth understanding of electron transport in the cascade structure is obtained. Finally, we demonstrate the feasibility of a modulation frequency up to gigahertz in terahertz QCLs.

F Wang; X G Guo; C Wang; J C Cao

2013-01-01T23:59:59.000Z

227

Fokker-Planck equation in mirror research  

SciTech Connect (OSTI)

Open confinement systems based on the magnetic mirror principle depend on the maintenance of particle distributions that may deviate substantially from Maxwellian distributions. Mirror research has therefore from the beginning relied on theoretical predictions of non-equilibrium rate processes obtained from solutions to the Fokker-Planck equation. The F-P equation plays three roles: Design of experiments, creation of classical standards against which to compare experiment, and predictions concerning mirror based fusion power systems. Analytical and computational approaches to solving the F-P equation for mirror systems will be reviewed, together with results and examples that apply to specific mirror systems, such as the tandem mirror.

Post, R.F.

1983-08-11T23:59:59.000Z

228

Efficiency of autonomous soft nano-machines at maximum power  

E-Print Network [OSTI]

We consider nano-sized artificial or biological machines working in steady state enforced by imposing non-equilibrium concentrations of solutes or by applying external forces, torques or electric fields. For unicyclic and strongly coupled multicyclic machines, efficiency at maximum power is not bounded by the linear response value 1/2. For strong driving, it can even approach the thermodynamic limit 1. Quite generally, such machines fall in three different classes characterized, respectively, as "strong and efficient", "strong and inefficient", and "balanced". For weakly coupled multicyclic machines, efficiency at maximum power has lost any universality even in the linear response regime.

Udo Seifert

2010-11-11T23:59:59.000Z

229

Method and apparatus for chemically altering fluids in continuous flow  

DOE Patents [OSTI]

The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation.

Heath, William O. (Richland, WA); Virden, Jr., Judson W. (Richland, WA); Richardson, R. L. (West Richland, WA); Bergsman, Theresa M. (Richland, WA)

1993-01-01T23:59:59.000Z

230

Method and apparatus for chemically altering fluids in continuous flow  

DOE Patents [OSTI]

The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation. 4 figures.

Heath, W.O.; Virden, J.W. Jr.; Richardson, R.L.; Bergsman, T.M.

1993-10-19T23:59:59.000Z

231

Nonlinear Dynamical Equation for Irreversible, Steepest-Entropy-Ascent Relaxation to Stable Equilibrium  

SciTech Connect (OSTI)

We discuss the structure and main features of the nonlinear evolution equation proposed by this author as the fundamental dynamical law within the framework of Quantum Thermodynamics. The nonlinear equation generates a dynamical group providing a unique deterministic description of irreversible, conservative relaxation towards equilibrium from any non-equilibrium state, and satisfies a very restrictive stability requirement equivalent to Hatsopoulos-Keenan statement of the second law of thermodynamics. Here, we emphasize its mathematical structure and its applicability also within other contexts, such as Classical and Quantum Statistical Mechanics, and Information Theory.

Beretta, Gian Paolo [Dipartimento di Ingegneria Meccanica, Universita degli Studi di Brescia, via Branze 38, 25123 Brescia (Italy)

2007-12-03T23:59:59.000Z

232

Microscopic origin of the second law of thermodynamics  

E-Print Network [OSTI]

We proved when random-variable fluctuations obey the central limit theorem the equality of the uncertainty relation corresponds to the thermodynamic equilibrium state. The inequality corresponds to the thermodynamic non-equilibrium state. The uncertainty relation is a quantum-mechanics expression of the second law of thermodynamics originated in wave-particle duality. Formulas of mean square-deviations changes adjusted by random fluctuations under the minimal uncertainty relation are obtained. Finally, an assumption is made which is waiting for examination. We except phase transitions in our discussion.

You-gang Feng

2005-05-29T23:59:59.000Z

233

Memory effects in radiative jet energy loss  

E-Print Network [OSTI]

In heavy-ion collisions the created quark-gluon plasma forms a quickly evolving background, leading to a time dependent radiative behavior of high momentum partons traversing the medium. We use the Schwinger Keldysh formalism to describe the jet evolution as a non-equilibrium process including the Landau-Pomeranschuk-Migdal effect. Concentrating on photon emission, a comparison of our results to a quasistatic calculation shows good agreement, leading to the conclusion that the radiative behavior follows the changes in the medium almost instantaneously.

Frank Michler; Björn Schenke; Carsten Greiner

2009-05-18T23:59:59.000Z

234

Entropy generation in a chemical reaction  

E-Print Network [OSTI]

Entropy generation in a chemical reaction is analyzed without using the general formalism of non-equilibrium thermodynamics at a level adequate for advanced undergraduates. In a first approach to the problem, the phenomenological kinetic equation of an elementary first order reaction is used to show that entropy production is always positive. A second approach assumes that the reaction is near equilibrium to prove that the entropy generated is always greater than zero, without any reference to the kinetics of the reaction. Finally, it is shown that entropy generation is related to fluctuations in the number of particles at equilibrium, i.e. it is associated to a microscopic process.

E. N. Miranda

2012-08-10T23:59:59.000Z

235

Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system  

Science Journals Connector (OSTI)

Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523?K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C2 hydrocarbon without coke formation at a ratio of CO2/Cfuel = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523?K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

Yasushi Sekine; Naotsugu Furukawa; Masahiko Matsukata; Eiichi Kikuchi

2011-01-01T23:59:59.000Z

236

Multiple-relaxation-time lattice Boltzmann kinetic model for combustion  

E-Print Network [OSTI]

To probe both the Mechanical Non-Equilibrium (MNE) and Thermodynamic Non-Equilibrium (TNE) in the combustion procedure, a two-dimensional Multiple-Relaxation-Time (MRT) version of the Lattice Boltzmann Kinetic Model(LBKM) for combustion phenomena is presented. The chemical energy released in the progress of combustion is dynamically coupled into the system by adding a chemical term to the LB kinetic equation. The LB model is required to recover the Navier-Stokes equations with chemical reaction in the hydrodynamic limit. To that aim, we construct a discrete velocity model with $24$ velocities divided into $3$ groups. In each group a flexible parameter is used to control the size of discrete velocities and a second parameter is used to describe the contribution of the extra degrees of freedom. The current model works for both subsonic and supersonic flows with or without chemical reaction. In this model both the specific-heat ratio and the Prandtl number are flexible, the TNE effects are naturally presented in...

Xu, Aiguo; Zhang, Guangcai; Li, Yingjun

2014-01-01T23:59:59.000Z

237

Nonuniqueness of two-temperature Guldberg-Waage and Saha equations: Influence on thermophysical properties of SF{sub 6} plasmas  

SciTech Connect (OSTI)

This paper focuses to study how the choice of Guldberg-Waage and Saha equations affects the thermodynamic properties and transport coefficients of SF{sub 6} plasmas under both thermal equilibrium and non-equilibrium conditions. The species composition is numerically determined using two typical forms of two-temperature Saha equations and Guldberg-Waage equations that have appeared in the literature. The great influence of the choice of the excitation temperature on the plasma composition and hence the thermodynamic properties and transport coefficients is discussed as well. Transport coefficients are calculated with most recent collision interaction potentials by adopting Devoto's electron and heavy particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) within the framework of Chapman-Enskog method. Furthermore, an analysis of the effect of different definitions of Debye length on the properties values was performed as well. The results are computed for various values of pressures from 0.10 atm to 10 atm and non-equilibrium parameter, i.e., ratio of the electron temperature to the heavy particle temperature from 1 to 5 with electron temperature range from 300 to 40 000 K. Both forms of Guldberg-Waage and Saha equations used here can give completely the same value when the two-temperature model reaches the special case of local thermodynamic equilibrium. It has been observed that all above mentioned factors can significantly modify the plasma species composition and consequently affect the thermodynamic and transport properties.

Wang, Weizong [Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094 (China) [Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China); Rong, Mingzhe [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China); Spencer, Joseph W. [Department of Electrical Engineering and Electronics, The University of Liverpool, Brownlow Hill, Liverpool L69 3GJ (United Kingdom)] [Department of Electrical Engineering and Electronics, The University of Liverpool, Brownlow Hill, Liverpool L69 3GJ (United Kingdom)

2013-11-15T23:59:59.000Z

238

Experimental observation of a phase transition in the evolution of many-body systems with dipolar interactions  

E-Print Network [OSTI]

Non-equilibrium dynamics of many-body systems is important in many branches of science, such as condensed matter, quantum chemistry, and ultracold atoms. Here we report the experimental observation of a phase transition of the quantum coherent dynamics of a 3D many-spin system with dipolar interactions, and determine its critical exponents. Using nuclear magnetic resonance (NMR) on a solid-state system of spins at room-temperature, we quench the interaction Hamiltonian to drive the evolution of the system. The resulting dynamics of the system coherence can be localized or extended, depending on the quench strength. Applying a finite-time scaling analysis to the observed time-evolution of the number of correlated spins, we extract the critical exponents v = s = 0.42 around the phase transition separating a localized from a delocalized dynamical regime. These results show clearly that such nuclear-spin based quantum simulations can effectively model the non-equilibrium dynamics of complex many-body systems, such as 3D spin-networks with dipolar interactions.

Gonzalo A. Alvarez; Dieter Suter; Robin Kaiser

2014-09-16T23:59:59.000Z

239

High-Throughput Thin Film Approach for Screening of Temperature-Pressure-Composition Phase Space  

SciTech Connect (OSTI)

Many solar energy technologies, for example CIGS and CdTe photovoltaics, utilize materials in thin film form. The equilibrium phase diagrams for these and other more novel solar energy materials are not known or are irrelevant because of the non-equilibrium character of the thin film growth processes. We demonstrate a high-throughput thin film approach for screening of temperature-pressure-composition phase diagrams and phase spaces. The examples in focus are novel solar absorbers Cu-N, Cu-O and p-type transparent conductors in the Cr2O3-MnO system. The composition axis of the Cr2O3-MnO phase diagram was screened using a composition spread method. The temperature axis of the Mn-O phase diagram was screened using a temperature spread method. The pressure axes of the Cu-N and Cu-O phase diagrams were screened using rate spread method with the aid of non-equilibrium growth phenomena. Overall these three methods constitute an approach to high-throughput screening of inorganic thin film phase diagrams. This research is supported by U.S. Department of Energy as a part of two NextGen Sunshot projects and an Energy Frontier Research Center.

Zakutayev, A.; Subramaniyan, A.; Caskey, C. M.; Ndione, P. F.; Richards, R. M.; O'Hayre, R.; Ginley, D. S.

2013-01-01T23:59:59.000Z

240

Tritium and neutron measurements of a solid state cell  

SciTech Connect (OSTI)

A solid state cold fusion'' cell was constructed to test for non-equilibrium fusion in a solid. The stimulus for the design was the hypothesis that the electrochemical surface layer in the Pons- Fleischmann cell could be replaced with a metal-insulator- semiconductor (MIS) barrier. Cells were constructed of alternating layers of palladium and silicon powders pressed into a ceramic form and exposed to deuterium gas at 110 psia resulting in a D/Pd ratio of 0.7. Pulses of current were passed through the cells to populate non-equilibrium states at the MIS barriers. One cell showed neutron activity and was found to have a large amount of tritium, other cells have produced tritium at a low rate consistent with neutron emission below the threshold of observability. The branching ratio for n/p has been about 1 {times} 10{sup {minus}9} in all the experiments where a substantial amount of tritium has been found. 11 refs., 9 figs., 2 tabs.

Claytor, T.N.; Seeger, P.A.; Rohwer, R.K.; Tuggle, D.G.; Doty, W.R.

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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to obtain the most current and comprehensive results.


241

Kenneth Gray - Argonne National Laboratories, Materials Sicence Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

EM > Kenneth Gray EM > Kenneth Gray Kenneth Gray Group Leader, Sr. Physicist Bldg. 223, A-125 Phone: 630-252-9595 This e-mail address is being protected from spambots. You need JavaScript enabled to view it. Biography Kenneth E. Gray is a Senior Scientist in the Materials Science Division. His experimental thesis involved tunneling studies of superconductors and non-equilibrium effects. He joined Argonne's superconductivity group as a post-doc, and in 1972 became a staff member specializing in non-equilibrium effects in superconductors. He is presently the group leader of the Emerging Materials Group. He was the Director for the NATO Advanced Study Institute "Nonequilibrium Superconductivity, Phonons and Kapitza Boundaries" Maratea, Italy, August 25-September 5, 1980 and Chairman of the "1992 Applied Superconductivity Conference" Chicago, Illinois, August 23-28, 1992. He was the Thin Film Research Area Coordinator for the NSF Science and Technology Center for Superconductivity (University of Illinois, Urbana), Feb. 1989-Jan. 1992. He edited Nonequilibrium Superconductivity, Phonons and Kapitza Boundaries, (Plenum Publishing Corporation, 1981). He holds 5 patents, and Research and Development Magazine recognized two of his inventions as among the 100 most significant technical products of their year. These are the Superconducting Tunnel Junction Transistor in 1979 and the 3He/4He Dilution Refrigerator (with P. Roach) in 1988. He received the 1989 Significant Implication for Department of Energy Related Technologies in Solid State Physics - "Thin-Film Superconducting Device Concepts and Development". He has co-authored 250 publications (5300 citations) and is known for research collaborations on flux dynamics and point-contact tunneling in high-temperature superconductors and transport measurements in the highly anisotropic colossal magnetoresistive layered manganites. He is a Senior Scientist and the Group Leader for the Emerging Materials Group at Argonne. His current research interests include tunneling in exotic superconductors, phase diagrams of layered manganites and non-equilibrium effects in complex electronic oxides. He was also an integral part of the recent development of a compact solid-state source for THz radiation.

242

U.S. Department of Energy Categorical Exclusion Determination Form  

Broader source: Energy.gov (indexed) [DOE]

Agency - Agency - Energy Pro-iectTitle: 0289-1600 Sheetak - Non-EquilibriumAsymmetric Thermoelectric Devices Location: Tennessee Proposed Action or Project Description: American Recovery and Reinvestment Act: Funding will support bench-scale research proposed work is consistent with the goals save energy and reduce GHG emissions. and development on a novel thermoelectric device for use in various air conditioning applications. The of BEETIT: the development of energy efficient cooling technologies and air conditioners for buildings, to Proposed work consists entirely of RD&D work to be completed in Sheetak's facilities in Austin, TX and the National Nanotechnology Infrastructure Network on the campus of the University of Texas - Austin in Austin, TX. The work performed will be limited

243

Slide 1  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Recovery from Recovery from Hydrate-bearing Sediments Prime Recipients J. Carlos Santamarina Georgia Tech Costas Tsouris ORNL/Georgia Tech Carolyn Ruppel USGS (no cost) Agreement Number DE-PS26-06NT42820 NETL Project Manager Timothy Grant Methane Hydrates Kick-Off Meeting Objective - Expected Benefits Hydrates * Seafloor instability [gigaton] [USGS] [Kvenvolden and Lorenson, 2001; www.pet.hw.ac.uk; Ballough et al.)] * Energy resource * Climate change: green house effect Challenge Methane production from hydrate-bearing sediments Understanding Prediction * Sediment properties * Hydrate formation history * Phases/fluids fronts * Effects of driving forces * Thermodynamics in confinement * Non-equilibrium analysis * Kinetics in confinement * Multiphase transport Keys: Energy Forms + Scales + Sediment

244

Albany, OR * Anchorage, AK * Morgantown, WV * Pittsburgh, PA * Sugar Land, TX  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Rodosta Rodosta Carbon Storage Technology Manager National Energy Technology Laboratory 3610 Collins Ferry Road P.O. Box 880 Morgantown, WV 26507 304-285-1345 traci.rodosta@netl.doe.gov Darin Damiani Project Manager National Energy Technology Laboratory 3610 Collins Ferry Road P.O. Box 880 Morgantown, WV 26507 304-285-4398 darin.damiani@netl.doe.gov Vivak Malhotra Principal Investigator Southern Illinois University Neckers 483A Mailcode: 4401 Carbondale, IL 62901 618-453-2643 Fax: 618-453-1056 vmalhotra@physics.siu.edu PARTNERS None Risk Assessment and Monitoring of Stored CO2 in Organic Rock under Non-Equilibrium Conditions Background Fundamental and applied research on carbon capture, utilization and storage (CCUS)

245

Science for the Future of RHIC  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

77334-2006-IR 77334-2006-IR Future Science at the Relativistic Heavy Ion Collider December 30, 2006 Summary of the 2004 - 2005 RHIC II Science Working Groups 1 2 Table of contents 1. Overview 4 2. Summary of the first 5 years at RHIC 9 2..1. Heavy ion physics 9 2..2. Spin physics 18 3. The RHIC facility - evolution and future 22 4. Fundamental questions for the next ten years at RHIC 25 4.1. What are the phases of QCD matter? 25 4.2. What is the wave function of a heavy nucleus. 26 4.3. What is the wave function of the proton? 26 4.4. What is the nature of non-equilibrium processes in a fundamental theory? 27 5. The future physics program at RHIC 28 5.1. Equation of state and the QCD phase diagram 29 5.1.1. Dynamical considerations 29

246

Marius Stan | Argonne National Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Marius Stan Senior Scientist - Nuclear Engineering Dr. Marius Stan is a physicist and a chemist interested in non-equilibrium thermodynamics, heterogeneity, and multi-scale computational science for energy applications. He came to Argonne and the University of Chicago in 2010, from Los Alamos National Laboratory. Marius is a Senior Fellow at the University of Chicago's Computation Institute. The goal of his research is to discover or design materials, structures, and device architectures for nuclear energy and energy storage. To that end, Marius develops theory-based (as opposite to empirical) mathematical models of thermomechanical and chemical properties of imperfect materials. The imperfection comes from defects or deviations from stoichiometry (e.g.,

247

Project Title  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

RISK ASSESSMENT AND MONITORING OF RISK ASSESSMENT AND MONITORING OF STORED CO 2 IN ORGANIC ROCKS UNDER NON- EQUILIBRIUM CONDITIONS DOE (NETL) Award Number: DE-FE0002423 Investigator: Vivak (Vik) Malhotra DOE supported undergraduate student participants: Jacob Huffstutler, Ryan Belscamper, Stephen Hofer, Kyle Flannery,, Bradley Wilson, Jamie Pfister, Jeffrey Pieper, Joshua T. Thompson, Collier Scalzitti-Sanders, and Shaun Wolfe Southern Illinois University-Carbondale Carbondale, Illinois 62901-4401 U.S. Department of Energy National Energy Technology Laboratory Carbon Storage R&D Project Review Meeting Developing the Technologies and Building the Infrastructure for CO 2 Storage August 21-23, 2012 2 Benefit to the Carbon Storage Program * Program goals being addressed: - To attempt to answer whether CO

248

Page not found | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

41 - 4150 of 8,172 results. 41 - 4150 of 8,172 results. Download CX-003453: Categorical Exclusion Determination Nebraska - Tribe - Winnebago Tribe CX(s) Applied: A9, A11, B5.1 Date: 08/10/2010 Location(s): Nebraska Office(s): Energy Efficiency and Renewable Energy http://energy.gov/nepa/downloads/cx-003453-categorical-exclusion-determination Download CX-004918: Categorical Exclusion Determination Sheetak -Non-Equilibrium Asymmetric Thermoelectric Devices CX(s) Applied: B3.6 Date: 08/10/2010 Location(s): Austin, Texas Office(s): Advanced Research Projects Agency - Energy http://energy.gov/nepa/downloads/cx-004918-categorical-exclusion-determination Download CX-003176: Categorical Exclusion Determination Chicago Area Alternative Fuels Deployment Project (Summary Categorical Exclusion) CX(s) Applied: A1, A9, B3.6, B5.1

249

Физическая природа долговечности металлов в явлении динамического разрушения  

National Nuclear Security Administration (NNSA)

Materials Ejecta, Spallation and Damage Materials Ejecta, Spallation and Damage Physical Nature of Metals Longevity in the Dynamic Failure Phenomenon A.Ya.Uchaev*, S.S. Sokolov*, N.I. Sel'chenkova*, E.V.Kosheleva*, and L.V. Zhabyka* * Russian Federal Nuclear Center - VNIIEF, Russia, 607188, Nizhni Novgorod region, Sarov, Mira Avenue 37 Summary: At present acute is the knowledge of time boundary of maintaining functional metal properties under extreme conditions, when the equilibrium state deviation value is comparable, for example, with phase transition energy. Results and Discussion As a rule, relaxation of strongly non-equilibrium states is accompanied by destruction processes [1], [2]. Capabilities of modern high-energy impulse scientific technology are directly associated with

250

Joint Institute for High Temperatures  

National Nuclear Security Administration (NNSA)

Joint Institute for High Temperatures of Russian Academy of Sciences Moscow Institute of Physics and Technology Extended title Extended title Excited state of warm dense matter or Exotic state of warm dense matter or Novel form of warm dense matter or New form of plasma Three sources of generation similarity: solid state density, two temperatures: electron temperature about tens eV, cold ions keep original crystallographic positions, but electron band structure and phonon dispersion are changed, transient but steady (quasi-stationary for a short time) state of non-equilibrium, uniform plasmas (no reference to non-ideality, both strongly and weakly coupled plasmas can be formed) spectral line spectra are emitted by ion cores embedded in plasma environment which influences the spectra strongly,

251

U.S. DEPARTMENT OF ENERGY - NETL CATEGORICAL EXCLUSION (CX) DESIGNATION FORM  

Broader source: Energy.gov (indexed) [DOE]

23 23 V. M. Malhotra FE DE-FE0002423 Sequestration Division 10 Darin Damiani 12/01/2009 - 11/30/2012 Carbondale, Illinois Risk Assessment and Monitoring of Stored of Non-Equilibrium Conditions on CO2 Stored in Organic Rocks This project involves laboratory research at bench-scale level with the aim to understand how carbon dioxide interacts with coal and how dynamic pressure waves modulate these interactions. Darin Damiani Digitally signed by Darin Damiani DN: cn=Darin Damiani, o=NETL, ou=Sequestration Division, email=darin.damiani@netl.doe.gov, c=US Reason: I am approving this document Date: 2009.12.02 14:55:14 -05'00' 12 02 2009 john ganz Digitally signed by john ganz DN: cn=john ganz, o=NETL- DOE, ou=140 OPFC, email=john.ganz@netl.doe.gov, c=US Date: 2009.12.11 10:03:44

252

Review of surface-modification programs in the DOE-OTM Tribology Program  

SciTech Connect (OSTI)

The use of surface-modification treatments is a widely accepted practice to reduce the wear and modify the friction behavior of surface regions while maintaining desirable bulk properties (e.g., strength, hardness, thermal conductivity, etc.) of the underlying substrate. These treatments range from conventional diffusion processes such as carburizing steels for case-hardening gears, to advanced non-equilibrium processes such as ion implantation or ion plating. The objective of this task area is to develop and investigate new or emerging surface-modification processes that show a potential for improving and controlling the tribological behavior of surfaces and thus permit engineers to design components for advanced heat engines based on desired bulk properties and near-surface tribological properties.

Fenske, G.R.; Nichols, F.A.

1991-02-01T23:59:59.000Z

253

Towards the Development of a Simulator for Investigating the Impact of People Management Practices on Retail Performance  

E-Print Network [OSTI]

Often models for understanding the impact of management practices on retail performance are developed under the assumption of stability, equilibrium and linearity, whereas retail operations are considered in reality to be dynamic, non-linear and complex. Alternatively, discrete event and agent-based modelling are approaches that allow the development of simulation models of heterogeneous non-equilibrium systems for testing out different scenarios. When developing simulation models one has to abstract and simplify from the real world, which means that one has to try and capture the 'essence' of the system required for developing a representation of the mechanisms that drive the progression in the real system. Simulation models can be developed at different levels of abstraction. To know the appropriate level of abstraction for a specific application is often more of an art than a science. We have developed a retail branch simulation model to investigate which level of model accuracy is required for such a mode...

Siebers, Peer-Olaf; Celia, Helen; Clegg, Chris

2010-01-01T23:59:59.000Z

254

Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions  

E-Print Network [OSTI]

The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.

Nikolai V. Priezjev

2012-08-27T23:59:59.000Z

255

Large linear magnetoresistance in a GaAs/AlGaAs heterostructure  

SciTech Connect (OSTI)

We report non-saturating linear magnetoresistance (MR) in a two-dimensional electron system (2DES) at a GaAs/AlGaAs heterointerface in the strongly insulating regime. We achieve this by driving the gate voltage below the pinch-off point of the device and operating it in the non-equilibrium regime with high source-drain bias. Remarkably, the magnitude of MR is as large as 500% per Tesla with respect to resistance at zero magnetic field, thus dwarfing most non-magnetic materials which exhibit this linearity. Its primary advantage over most other materials is that both linearity and the enormous magnitude are retained over a broad temperature range (0.3 K to 10 K), thus making it an attractive candidate for cryogenic sensor applications.

Aamir, Mohammed Ali, E-mail: aamir@physics.iisc.ernet.in; Goswami, Srijit, E-mail: aamir@physics.iisc.ernet.in; Ghosh, Arindam [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India); Baenninger, Matthias; Farrer, Ian; Ritchie, David A. [Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Tripathi, Vikram [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Pepper, Michael [Department of Electrical and Electronic Engineering, University College, London WC1E 7JE (United Kingdom)

2013-12-04T23:59:59.000Z

256

Elliptic flow of heavy flavors  

E-Print Network [OSTI]

The propagation of charm and bottom quarks through a ellipsoidal domain of quark gluon plasma has been studied within the ambit of non-equilibrium statistical mechanics. Energy dissipation of heavy quarks by both radiative and collisional processes are taken in to account. The experimental data on the elliptic flow of the non-photonic electrons resulting from the semi-leptonic decays of hadrons containing heavy flavours has been reproduced with the same formalism that has been used earlier to reproduce the nuclear suppression factors. The elliptic flow of the non-photonic electron from heavy meson decays produced in nuclear collisions at LHC and low energy RHIC run have also been predicted.

Das, Santosh K

2010-01-01T23:59:59.000Z

257

Elliptic flow of heavy flavors  

E-Print Network [OSTI]

The propagation of charm and bottom quarks through an ellipsoidal domain of quark gluon plasma has been studied within the ambit of non-equilibrium statistical mechanics. Energy dissipation of heavy quarks by both radiative and collisional processes are taken in to account. The experimental data on the elliptic flow of the non-photonic electrons resulting from the semi-leptonic decays of hadrons containing heavy flavours has been reproduced with the same formalism that has been used earlier to reproduce the nuclear suppression factors. The elliptic flow of the non-photonic electron from heavy meson decays produced in nuclear collisions at LHC and low energy RHIC run have also been predicted.

Santosh K Das; Jan-e Alam

2010-08-16T23:59:59.000Z

258

Impact of nanostructure configuration on the photovoltaic performance of quantum dot arrays  

E-Print Network [OSTI]

In this work, an effective quantum model based on the non-equilibrium Green's function formalism is used to investigate a selectively contacted high density quantum dot array in an wide band gap host matrix for operation as a quantum dot-enhanced single junction solar cell. By establishing a direct relation between nanostructure configuration and optoelectronic properties, the investigation reveals the influence of inter-dot and dot-contact coupling strength on the radiative rates and consequently on the ultimate performance of photovoltaic devices with finite quantum dot arrays as the active medium. The dominant effects originate in the dependence of the Joint Density of States on the inter-dot coupling in terms of band width and effective band gap.

Berbezier, Aude

2014-01-01T23:59:59.000Z

259

Kinetics of electron-positron pair plasmas using an adaptive Monte Carlo method  

E-Print Network [OSTI]

A new algorithm for implementing the adaptive Monte Carlo method is given. It is used to solve the relativistic Boltzmann equations that describe the time evolution of a nonequilibrium electron-positron pair plasma containing high-energy photons and pairs. The collision kernels for the photons as well as pairs are constructed for Compton scattering, pair annihilation and creation, bremsstrahlung, and Bhabha & Moller scattering. For a homogeneous and isotropic plasma, analytical equilibrium solutions are obtained in terms of the initial conditions. For two non-equilibrium models, the time evolution of the photon and pair spectra is determined using the new method. The asymptotic numerical solutions are found to be in a good agreement with the analytical equilibrium states. Astrophysical applications of this scheme are discussed.

Ravi P. Pilla; Jacob Shaham

1997-02-21T23:59:59.000Z

260

Epidemic processes in complex networks  

E-Print Network [OSTI]

In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and socio-technical systems. The complex properties of real world networks have a profound impact on the behavior of equilibrium and non-equilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The theoretical analysis of epidemic spreading in heterogeneous networks requires the development of novel analytical frameworks, and it has produced results of conceptual and practical relevance. Here we present a coherent and comprehensive review of the vast research activity concerning epidemic processes, detailing the successful theoretical approaches as well as making their limits and assumptions clear. Physicists, epidemiologists, computer and social scientists share a common interest in studying epidemic spreading and...

Pastor-Satorras, Romualdo; Van Mieghem, Piet; Vespignani, Alessandro

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Statistical Physics approach to dendritic computation: The excitable-wave mean-field approximation  

E-Print Network [OSTI]

We analytically study the input-output properties of a neuron whose active dendritic tree, modeled as a Cayley tree of excitable elements, is subjected to Poisson stimulus. Both single-site and two-site mean-field approximations incorrectly predict a non-equilibrium phase transition which is not allowed in the model. We propose an excitable-wave mean-field approximation which shows good agreement with previously published simulation results [Gollo et al., PLoS Comput. Biol. 5(6) e1000402 (2009)] and accounts for finite-size effects. We also discuss the relevance of our results to experiments in neuroscience, emphasizing the role of active dendrites in the enhancement of dynamic range and in gain control modulation.

Leonardo L. Gollo; Osame Kinouchi; Mauro Copelli

2011-09-09T23:59:59.000Z

262

Modeling Scattering Polarization for Probing Solar Magnetism  

E-Print Network [OSTI]

This paper considers the problem of modeling the light polarization that emerges from an astrophysical plasma composed of atoms whose excitation state is significantly influenced by the anisotropy of the incident radiation field. In particular, it highlights how radiative transfer simulations in three-dimensional models of the quiet solar atmosphere may help us to probe its thermal and magnetic structure, from the near equilibrium photosphere to the highly non-equilibrium upper chromosphere. The paper finishes with predictions concerning the amplitudes and magnetic sensitivities of the linear polarization signals produced by scattering processes in two transition region lines, which should encourage us to develop UV polarimeters for sounding rockets and space telescopes with the aim of opening up a new diagnostic window in astrophysics.

Bueno, Javier Trujillo

2011-01-01T23:59:59.000Z

263

Exploding Wire in Water as a Potential Source of Amplified EUV-radiation  

SciTech Connect (OSTI)

Proximity wall stabilized, fast (>4x10{sup 11} A/s), high current (>40 kA) discharges are capable to create long, dense, hot, 'stable,' non-equilibrium plasma column suitable e.g. for amplification of EUV and soft X-ray radiation. Exploding wire in water resembles a metal-vapor-filled capillary with liquid, ever fresh wall (without any metallic deposit). Modeling of wire explosion (inclusive melting and boiling phase transitions, thermal diffusion, and non-constant conductivity) by the originally skinned driving current is described. Modeling results are compared with measurement of the discharge current and with side-on monitoring of H-alpha line emission. The differences are attributed to the fact that for calculation the material constants measured at atmospheric pressure were available only.

Kolacek, Karel; Prukner, Vaclav; Schmidt, Jiri; Straus, Jaroslav; Frolov, Oleksandr; Hoffer, Petr [Institute of Plasma Physics, Academy of Sciences of the Czech Republic, v.v.i. Za Slovankou 1782/3, 182 00 Prague 8 (Czech Republic)

2009-01-21T23:59:59.000Z

264

Response to ''Comment on 'Heating of ions by low-frequency Alfven waves in partially ionized plasmas''' [Phys. Plasmas 18, 084703 (2011)  

SciTech Connect (OSTI)

The calculation of temperature in a plasma system that is not in thermal equilibrium remains a topic of debate. In our article [Dong and Paty, Phys. Plasmas 18, 030702 (2011)] we use the average kinetic energy to calculate the ''kinetic temperature'' in a non-equilibrium system to quantify the heating of ions by low-frequency Alfven waves in a partially ionized plasma (i.e., where collisions with neutrals can not be ignored). We implement a method previously used by Wang, Wu and Yoon [Wang, Wu and Yoon, Phys. Rev. Lett. 96, 125001 (2006)] and several others studying the effects of low frequency Alfven waves in collisionless plasmas. This method is appropriate for several reasons discussed in this response. Most notably, we implement it to investigate heating of the plasma population since the bulk velocity of the particle ensemble perpendicular to the ambient magnetic field remains zero during the numerical experiment.

Dong Chuanfei [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Paty, Carol S. [School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2011-08-15T23:59:59.000Z

265

Rate-dependent morphology of Li2O2 growth in Li-O2 batteries  

E-Print Network [OSTI]

Compact solid discharge products enable energy storage devices with high gravimetric and volumetric energy densities, but solid deposits on active surfaces can disturb charge transport and induce mechanical stress. In this Letter we develop a nanoscale continuum model for the growth of Li2O2 crystals in lithium-oxygen batteries with organic electrolytes, based on a theory of electrochemical non-equilibrium thermodynamics originally applied to Li-ion batteries. As in the case of lithium insertion in phase-separating LiFePO4 nanoparticles, the theory predicts a transition from complex to uniform morphologies of Li2O2 with increasing current. Discrete particle growth at low discharge rates becomes suppressed at high rates, resulting in a film of electronically insulating Li2O2 that limits cell performance. We predict that the transition between these surface growth modes occurs at current densities close to the exchange current density of the cathode reaction, consistent with experimental observations.

Horstmann, B; Mitchell, R; Bessler, W G; Shao-Horn, Y; Bazant, M Z

2013-01-01T23:59:59.000Z

266

States with identical steady dissipation rate: Role of kinetic constants in enzyme catalysis  

E-Print Network [OSTI]

A non-equilibrium steady state is characterized by a non-zero steady dissipation rate. Chemical reaction systems under suitable conditions may generate such states. We propose here a method that is able to distinguish states with identical values of the steady dissipation rate. This necessitates a study of the variation of the entropy production rate with the experimentally observable reaction rate in regions close to the steady states. As an exactly-solvable test case, we choose the problem of enzyme catalysis. Link of the total entropy production with the enzyme efficiency is also established, offering a desirable connection with the inherent irreversibility of the process. The chief outcomes are finally noted in a more general reaction network with numerical demonstrations.

Banerjee, Kinshuk

2014-01-01T23:59:59.000Z

267

Prediction of Transport Properties by Molecular Simulation: Methanol and Ethanol and their mixture  

E-Print Network [OSTI]

Transport properties of liquid methanol and ethanol are predicted by molecular dynamics simulation. The molecular models for the alcohols are rigid, non-polarizable and of united-atom type. They were developed in preceding work using experimental vapor-liquid equilibrium data only. Self- and Maxwell-Stefan diffusion coefficients as well as the shear viscosity of methanol, ethanol and their binary mixture are determined using equilibrium molecular dynamics and the Green-Kubo formalism. Non-equilibrium molecular dynamics is used for predicting the thermal conductivity of the two pure substances. The transport properties of the fluids are calculated over a wide temperature range at ambient pressure and compared with experimental and simulation data from the literature. Overall, a very good agreement with the experiment is found. For instance, the self-diffusion coefficient and the shear viscosity are predicted with average deviations of less 8% for the pure alcohols and 12% for the mixture. The predicted thermal...

Guevara-Carrion, Gabriela; Vrabec, Jadran; Hasse, Hans

2009-01-01T23:59:59.000Z

268

Work extraction and thermodynamics for individual quantum systems  

E-Print Network [OSTI]

Thermodynamics is traditionally concerned with systems comprised of a large number of particles. Here we present a framework for extending thermodynamics to individual quantum systems, including explicitly a thermal bath and work-storage device (essentially a `weight' that can be raised or lowered). We prove that the second law of thermodynamics holds in our framework, and give a simple protocol to extract the optimal amount of work from the system, equal to its change in free energy. Our results apply to any quantum system in an arbitrary initial state, in particular including non-equilibrium situations. The optimal protocol is essentially reversible, similar to classical Carnot cycles, and indeed, we show that it can be used it to construct a quantum Carnot engine.

Paul Skrzypczyk; Anthony J. Short; Sandu Popescu

2014-09-26T23:59:59.000Z

269

C/CrC nanocomposite coating deposited by magnetron sputtering at high ion irradiation conditions  

SciTech Connect (OSTI)

CrC with the fcc NaCl (B1) structure is a metastable phase that can be obtained under the non-equilibrium conditions of high ion irradiation. A nano-composite coating consisting of amorphous carbon embedded in a CrC matrix was prepared via the unbalanced magnetron sputtering of graphite and Cr metal targets in Ar gas with a high ionized flux (ion-to-neutral ratio Ji/Jn = 6). The nanoscale amorphous carbon clusters self-assembled into layers alternated by CrC, giving the composite a multilayer structure. The phase, microstructure, and composition of the coating were characterized using x-ray diffraction, transmission electron microscopy, and aberration corrected scanning transmission electron microscopy coupled with electron energy loss spectroscopy. The interpretation of the true coating structure, in particular the carbide type, is discussed.

Zhou, Z.; Rainforth, W. M. [Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD (United Kingdom); Gass, M. H.; Bleloch, A. [SuperSTEM at Daresbury Laboratory, Daresbury, Cheshire, WA4 4AD (United Kingdom); Ehiassarian, A. P.; Hovsepian, P. Eh. [Materials Engineering Research Institute, Sheffield Hallam University, Sheffield, S1 1WB (United Kingdom)

2011-10-01T23:59:59.000Z

270

A Green's function formalism of energy and momentum transfer in fluctuational electrodynamics  

E-Print Network [OSTI]

Radiative energy and momentum transfer due to fluctuations of electromagnetic fields arising due to temperature difference between objects is described in terms of the cross-spectral densities of the electromagnetic fields. We derive relations between thermal non-equilibrium contributions to energy and momentum transfer and surface integrals of tangential components of the dyadic Green's functions of the vector Helmholtz equation. The expressions derived here are applicable to objects of arbitrary shapes, dielectric functions, as well as magnetic permeabilities. For the case of radiative transfer, we derive expressions for the generalized transmissivity and generalized conductance that are shown to obey reciprocity and agree with theory of black body radiative transfer in the appropriate limit.

Arvind Narayanaswamy; Yi Zheng

2013-02-03T23:59:59.000Z

271

Experimental demonstration of hot-carrier photo-current in an InGaAs quantum well solar cell  

SciTech Connect (OSTI)

An unambiguous observation of hot-carrier photocurrent from an InGaAs single quantum well solar cell is reported. Simultaneous photo-current and photoluminescence measurements were performed for incident power density 0.04–3?kW cm{sup ?2}, lattice temperature 10?K, and forward bias 1.2?V. An order of magnitude photocurrent increase was observed for non-equilibrium hot-carrier temperatures >35?K. This photocurrent activation temperature is consistent with that of equilibrium carriers in a lattice at elevated temperature. The observed hot-carrier photo-current is extracted from the well over an energy selective GaAs barrier, thus integrating two essential components of a hot-carrier solar cell: a hot-carrier absorber and an energy selective contact.

Hirst, L. C.; Walters, R. J. [U.S. Naval Research Laboratory, 4555 Overlook Ave. SW., Washington, DC 20375 (United States); Führer, M. F.; Ekins-Daukes, N. J. [Imperial College London, London SW7 2AZ (United Kingdom)

2014-06-09T23:59:59.000Z

272

A boron nitride nanotube peapod thermal rectifier  

SciTech Connect (OSTI)

The precise guidance of heat from one specific location to another is paramount in many industrial and commercial applications, including thermal management and thermoelectric generation. One of the cardinal requirements is a preferential conduction of thermal energy, also known as thermal rectification, in the materials. This study introduces a novel nanomaterial for rectifying heat—the boron nitride nanotube peapod thermal rectifier. Classical non-equilibrium molecular dynamics simulations are performed on this nanomaterial, and interestingly, the strength of the rectification phenomenon is dissimilar at different operating temperatures. This is due to the contingence of the thermal flux on the conductance at the localized region around the scatterer, which varies with temperature. The rectification performance of the peapod rectifier is inherently dependent on its asymmetry. Last but not least, the favourable rectifying direction in the nanomaterial is established.

Loh, G. C., E-mail: jgloh@mtu.edu [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States); Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore); Baillargeat, D. [CNRS-International-NTU-Thales Research Alliance (CINTRA), 50 Nanyang Drive, Singapore 637553 (Singapore)

2014-06-28T23:59:59.000Z

273

Modulation of the electron transport properties in graphene nanoribbons doped with BN chains  

SciTech Connect (OSTI)

Using density-functional theory and the non-equilibrium Green's function method, the electron transport properties of zigzag graphene nanoribbons (ZGNRs) doped with BN chains are studied by systematically calculating the energy band structure, density of states and the transmission spectra for the systems. The BN chains destroyed the electronic transport properties of the ZGNRs, and an energy gap appeared for the ZGNRs, and displayed variations from a metal to a wide-gap semiconductor. With an increase in the number of BN chains, the band gap increased gradually in the band structure and the transmission coefficient decreased near the Fermi surface. Additionally, the doping position had a significant effect on the electronic properties of the ZGNRs.

Liu, Wu; Zhang, Kaiwang, E-mail: kwzhang@xtu.edu.cn; Zhong, JianXin [Department of Physics, Xiangtan University, Xiangtan 411105 (China); Wang, Ru-Zhi, E-mail: wrz@bjut.edu.cn [College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Liu, Li-Min, E-mail: limin.liu@csrc.ac.cn [Beijing Computational Science Research Centre, Beijing, 100084 (China)

2014-06-15T23:59:59.000Z

274

The dynamics of technology diffusion and the impacts of climate policy instruments in the decarbonisation of the global electricity sector  

E-Print Network [OSTI]

This paper presents an analysis of possible uses of climate policy instruments for the decarbonisation of the global electricity sector in a non-equilibrium economic and technology innovation-diffusion perspective. Emissions reductions occur through changes in technology and energy consumption; in this context, investment decision-making opportunities occur periodically, which energy policy can incentivise in order to transform energy systems and meet reductions targets. Energy markets are driven by innovation, dynamic costs and technology diffusion; yet, the incumbent systems optimisation methodology in energy modelling does not address these aspects nor the effectiveness of policy onto decision-making since the dynamics modelled take their source from the top-down `social-planner' assumption. This leads to an underestimation of strong technology lock-ins in cost-optimal scenarios of technology. Our approach explores the global diffusion of low carbon technology in connection to a highly disaggregated sector...

Mercure, J -F; Foley, A M; Chewpreecha, U; Pollitt, H

2013-01-01T23:59:59.000Z

275

Chiral Edge Currents in a Holographic Josephson Junction  

E-Print Network [OSTI]

We discuss the Josephson effect and the appearance of dissipationless edge currents in a holographic Josephson junction configuration involving a chiral, time-reversal breaking, superconductor in 2+1 dimensions. Such a superconductor is expected to be topological, thereby supporting topologically protected gapless Majorana-Weyl edge modes. Such modes manifest themselves in chiral dissipationless edge currents, which we exhibit and investigate in the context of our construction. The physics of the Josephson current itself, though expected to be unconventional in some non-equilibrium settings, is shown to be conventional in our setup which takes place in thermal equilibrium. We comment on various ways in which the expected Majorana nature of the edge excitations, and relatedly the unconventional nature of topological Josephson junctions, can be verified in the holographic context.

Rozali, Moshe

2013-01-01T23:59:59.000Z

276

Inferring metabolic phenotypes from the exometabolome through a thermodynamic variational principle  

E-Print Network [OSTI]

Networks of biochemical reactions, like cellular metabolic networks, are kept in non-equilibrium steady states by the exchange fluxes connecting them to the environment. In most cases, feasible flux configurations can be derived from minimal mass-balance assumptions upon prescribing in- and out-take fluxes. Here we consider the problem of inferring intracellular flux patterns from extracellular metabolite levels. Resorting to a thermodynamic out of equilibrium variational principle to describe the network at steady state, we show that the switch from fermentative to oxidative phenotypes in cells can be characterized in terms of the glucose, lactate, oxygen and carbon dioxide concentrations. Results obtained for an exactly solvable toy model are fully recovered for a large scale reconstruction of human catabolism. Finally we argue that, in spite of the many approximations involved in the theory, available data for several human cell types are well described by the predicted phenotypic map of the problem.

De Martino, Daniele; De Martino, Andrea

2014-01-01T23:59:59.000Z

277

Hydrocarbon sensors and materials therefor  

DOE Patents [OSTI]

An electrochemical hydrocarbon sensor and materials for use in sensors. A suitable proton conducting electrolyte and catalytic materials have been found for specific application in the detection and measurement of non-methane hydrocarbons. The sensor comprises a proton conducting electrolyte sandwiched between two electrodes. At least one of the electrodes is covered with a hydrocarbon decomposition catalyst. Two different modes of operation for the hydrocarbon sensors can be used: equilibrium versus non-equilibrium measurements and differential catalytic. The sensor has particular application for on-board monitoring of automobile exhaust gases to evaluate the performance of catalytic converters. In addition, the sensor can be utilized in monitoring any process where hydrocarbons are exhausted, for instance, industrial power plants. The sensor is low cost, rugged, sensitive, simple to fabricate, miniature, and does not suffer cross sensitivities.

Pham, Ai Quoc (San Jose, CA); Glass, Robert S. (Livermore, CA)

2000-01-01T23:59:59.000Z

278

Observation of crystallization slowdown in supercooled para-hydrogen and ortho-deuterium quantum liquid mixtures  

E-Print Network [OSTI]

We report a quantitative experimental study of the crystallization kinetics of supercooled quantum liquid mixtures of para-hydrogen (pH$_2$) and ortho-deuterium (oD$_2$) by high spatial resolution Raman spectroscopy of liquid microjets. We show that in a wide range of compositions the crystallization rate of the isotopic mixtures is significantly reduced with respect to that of the pure substances. To clarify this behavior we have performed path-integral simulations of the non-equilibrium pH$_2$-oD$_2$ liquid mixtures, revealing that differences in quantum delocalization between the two isotopic species translate into different effective particle sizes. Our results provide first experimental evidence for crystallization slowdown of quantum origin, offering a benchmark for theoretical studies of quantum behavior in supercooled liquids.

Matthias Kühnel; José M. Fernández; Filippo Tramonto; Guzmán Tejeda; Elena Moreno; Anton Kalinin; Marco Nava; Davide E. Galli; Salvador Montero; Robert E. Grisenti

2014-10-10T23:59:59.000Z

279

N-type doping of Ge by As implantation and excimer laser annealing  

SciTech Connect (OSTI)

The diffusion and activation of arsenic implanted into germanium at 40?keV with maximum concentrations below and above the solid solubility (8?×?10{sup 19}?cm{sup ?3}) have been studied, both experimentally and theoretically, after excimer laser annealing (??=?308?nm) in the melting regime with different laser energy densities and single or multiple pulses. Arsenic is observed to diffuse similarly for different fluences with no out-diffusion and no formation of pile-up at the maximum melt depth. The diffusion profiles have been satisfactorily simulated by assuming two diffusivity states of As in the molten Ge and a non-equilibrium segregation at the maximum melt depth. The electrical activation is partial and decreases with increasing the chemical concentration with a saturation of the active concentration at 1?×?10{sup 20}?cm{sup ?3}, which represents a new record for the As-doped Ge system.

Milazzo, R.; Napolitani, E., E-mail: enrico.napolitani@unipd.it; De Salvador, D.; Mastromatteo, M.; Carnera, A. [CNR-IMM MATIS and Dipartimento di Fisica Astronomia, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); Impellizzeri, G.; Boninelli, S.; Priolo, F.; Privitera, V. [CNR-IMM MATIS and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Fisicaro, G.; Italia, M.; La Magna, A. [CNR-IMM, Z.I. VIII Strada 5, 95121 Catania (Italy); Cuscunà, M.; Fortunato, G. [CNR-IMM, Via del Fosso del Cavaliere 100, 00133 Roma (Italy)

2014-02-07T23:59:59.000Z

280

Chiral Edge Currents in a Holographic Josephson Junction  

E-Print Network [OSTI]

We discuss the Josephson effect and the appearance of dissipationless edge currents in a holographic Josephson junction configuration involving a chiral, time-reversal breaking, superconductor in 2+1 dimensions. Such a superconductor is expected to be topological, thereby supporting topologically protected gapless Majorana-Weyl edge modes. Such modes manifest themselves in chiral dissipationless edge currents, which we exhibit and investigate in the context of our construction. The physics of the Josephson current itself, though expected to be unconventional in some non-equilibrium settings, is shown to be conventional in our setup which takes place in thermal equilibrium. We comment on various ways in which the expected Majorana nature of the edge excitations, and relatedly the unconventional nature of topological Josephson junctions, can be verified in the holographic context.

Moshe Rozali; Alexandre Vincart-Emard

2013-11-28T23:59:59.000Z

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281

Phase Transformations in Confined Nanosystems  

SciTech Connect (OSTI)

This project discovered that non-equilibrium structures, including chemically ordered structures not observed in bulk systems, form in isolated nanoscale systems. Further, a generalized model was developed that effectively explained the suppression of equilibrium phase transformations. This thermodynamic model considered the free energy decrease associated with the phase transformation was less than the increase in energy associated with the formation of an interphase interface, therefore inhibiting the phase transformation. A critical diameter exists where the system transitions to bulk behavior, and a generalized equation was formulated that successfully predicted this transition in the Fe-Au system. This provided and explains a new route to novel structures not possible in bulk systems. The structural characterization was accomplished using transmission electron microscopy in collaboration with Matthew Kramer of Ames Laboratory. The PI and graduate student visited Ames Laboratory several times a year to conduct the experiments.

Shield, Jeffrey E. [Department of Mechanical & Materials Engineering] [Department of Mechanical & Materials Engineering; Belashchenko, Kirill [Department of Physics & Astronomy] [Department of Physics & Astronomy

2014-04-29T23:59:59.000Z

282

ls1 mardyn: The massively parallel molecular dynamics code for large systems  

E-Print Network [OSTI]

The molecular dynamics simulation code ls1 mardyn is presented. It is a highly scalable code, optimized for massively parallel execution on supercomputing architectures, and currently holds the world record for the largest molecular simulation with over four trillion particles. It enables the application of pair potentials to length and time scales which were previously out of scope for molecular dynamics simulation. With an efficient dynamic load balancing scheme, it delivers high scalability even for challenging heterogeneous configurations. Presently, multi-center rigid potential models based on Lennard-Jones sites, point charges and higher-order polarities are supported. Due to its modular design, ls1 mardyn can be extended to new physical models, methods, and algorithms, allowing future users to tailor it to suit their respective needs. Possible applications include scenarios with complex geometries, e.g. for fluids at interfaces, as well as non-equilibrium molecular dynamics simulation of heat and mass transfer.

Christoph Niethammer; Stefan Becker; Martin Bernreuther; Martin Buchholz; Wolfgang Eckhardt; Alexander Heinecke; Stephan Werth; Hans-Joachim Bungartz; Colin W. Glass; Hans Hasse; Jadran Vrabec; Martin Horsch

2014-08-20T23:59:59.000Z

283

Communication: Electronic and transport properties of molecular junctions under a finite bias: A dual mean field approach  

SciTech Connect (OSTI)

We show that when a molecular junction is under an external bias, its properties cannot be uniquely determined by the total electron density in the same manner as the density functional theory for ground state properties. In order to correctly incorporate bias-induced nonequilibrium effects, we present a dual mean field (DMF) approach. The key idea is that the total electron density together with the density of current-carrying electrons are sufficient to determine the properties of the system. Two mean fields, one for current-carrying electrons and the other one for equilibrium electrons can then be derived. Calculations for a graphene nanoribbon junction show that compared with the commonly used ab initio transport theory, the DMF approach could significantly reduce the electric current at low biases due to the non-equilibrium corrections to the mean field potential in the scattering region.

Liu, Shuanglong; Feng, Yuan Ping [Department of Physics and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)] [Department of Physics and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Zhang, Chun, E-mail: phyzc@nus.edu.sg [Department of Physics and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore) [Department of Physics and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore)

2013-11-21T23:59:59.000Z

284

Metal-poor dwarf galaxies in the SIGRID galaxy sample. II. The electron temperature-abundance calibration and the parameters that affect it  

E-Print Network [OSTI]

In this paper, we use the Mappings photoionization code to explore the physical parameters that impact on the measurement of electron temperature and abundance in HII regions. In the previous paper we presented observations and measurements of physical properties from the spectra of seventeen HII regions in fourteen isolated dwarf irregular galaxies from the SIGRID sample. Here, we analyze these observations further, together with three additional published data sets. We explore the effects of optical thickness, electron density, ionization parameter, ionization source, and non-equilibrium effects on the relation between electron temperature and metallicity. We present a standard model that fits the observed data remarkably well at metallicities between 1/10 and 1 solar. We investigate the effects of optically thin HII regions, and show that they can have a considerable effect on the measured electron temperature, and that there is evidence that some of the observed objects are optically thin. We look at the ...

Nicholls, David C; Sutherland, Ralph S; Jerjen, Helmut; Kewley, Lisa J; Basurah, Hassan

2014-01-01T23:59:59.000Z

285

High-resolution spectroscopy for Doppler-broadening ion temperature measurements of implosions at the National Ignition Facility  

SciTech Connect (OSTI)

Future implosion experiments at the national ignition facility (NIF) will endeavor to simultaneously measure electron and ion temperatures with temporal and spatial resolution in order to explore non-equilibrium temperature distributions and their relaxation toward equilibrium. In anticipation of these experiments, and with understanding of the constraints of the NIF facility environment, we have explored the use of Doppler broadening of mid-Z dopant emission lines, such as krypton He-{alpha} at 13 keV, as a diagnostic of time- and potentially space-resolved ion temperature. We have investigated a number of options analytically and with numerical raytracing, and we have identified several promising candidate spectrometer designs that meet the expected requirements of spectral and temporal resolution and data signal-to-noise ratio for gas-filled exploding pusher implosions, while providing maximum flexibility for use on a variety of experiments that potentially include burning plasma.

Koch, J. A.; Stewart, R. E.; Beiersdorfer, P.; Shepherd, R.; Schneider, M. B.; Miles, A. R.; Scott, H. A.; Smalyuk, V. A.; Hsing, W. W. [Lawrence Livermore National Laboratory, P.O. Box 808, L-493, Livermore, California 94550 (United States)

2012-10-15T23:59:59.000Z

286

Shortcuts to adiabaticity for trapped ultracold gases  

E-Print Network [OSTI]

We study, experimentally and theoretically, the controlled transfer of harmonically trapped ultracold gases between different quantum states. In particular we experimentally demonstrate a fast decompression and displacement of both a non-interacting gas and an interacting Bose-Einstein condensate which are initially at equilibrium. The decompression parameters are engineered such that the final state is identical to that obtained after a perfectly adiabatic transformation despite the fact that the fast decompression is performed in the strongly non-adiabatic regime. During the transfer the atomic sample goes through strongly out-of-equilibrium states while the external confinement is modified until the system reaches the desired stationary state. The scheme is theoretically based on the invariants of motion and scaling equations techniques and can be generalized to decompression trajectories including an arbitrary deformation of the trap. It is also directly applicable to arbitrary initial non-equilibrium sta...

Schaff, Jean-François; Labeyrie, Guillaume; Vignolo, Patrizia

2011-01-01T23:59:59.000Z

287

Shortcuts to adiabaticity for trapped ultracold gases  

E-Print Network [OSTI]

We study, experimentally and theoretically, the controlled transfer of harmonically trapped ultracold gases between different quantum states. In particular we experimentally demonstrate a fast decompression and displacement of both a non-interacting gas and an interacting Bose-Einstein condensate which are initially at equilibrium. The decompression parameters are engineered such that the final state is identical to that obtained after a perfectly adiabatic transformation despite the fact that the fast decompression is performed in the strongly non-adiabatic regime. During the transfer the atomic sample goes through strongly out-of-equilibrium states while the external confinement is modified until the system reaches the desired stationary state. The scheme is theoretically based on the invariants of motion and scaling equations techniques and can be generalized to decompression trajectories including an arbitrary deformation of the trap. It is also directly applicable to arbitrary initial non-equilibrium states.

Jean-François Schaff; Pablo Capuzzi; Guillaume Labeyrie; Patrizia Vignolo

2011-05-11T23:59:59.000Z

288

Statistical physics of cerebral embolization leading to stroke  

E-Print Network [OSTI]

We discuss the physics of embolic stroke using a minimal model of emboli moving through the cerebral arteries. Our model of the blood flow network consists of a bifurcating tree, into which we introduce particles (emboli) that halt flow on reaching a node of similar size. Flow is weighted away from blocked arteries, inducing an effective interaction between emboli. We justify the form of the flow weighting using a steady flow (Poiseuille) analysis and a more complicated nonlinear analysis. We discuss free flowing and heavily congested limits and examine the transition from free flow to congestion using numerics. The correlation time is found to increase significantly at a critical value, and a finite size scaling is carried out. An order parameter for non-equilibrium critical behavior is identified as the overlap of blockages' flow shadows. Our work shows embolic stroke to be a feature of the cerebral blood flow network on the verge of a phase transition.

J. P. Hague; E. M. L. Chung

2009-10-21T23:59:59.000Z

289

Spectroscopic temperature measurements of air breakdown plasma using a 110 GHz megawatt gyrotron beam  

SciTech Connect (OSTI)

Temperature measurements are presented of a non-equilibrium air breakdown plasma using optical emission spectroscopy. A plasma is created with a focused 110 GHz 3 {mu}s pulse gyrotron beam in air that produces power fluxes exceeding 1 MW/cm{sup 2}. Rotational and vibrational temperatures are spectroscopically measured over a pressure range of 1-100 Torr as the gyrotron power is varied above threshold. The temperature dependence on microwave field as well as pressure is examined. Rotational temperature measurements of the plasma reveal gas temperatures in the range of 300-500 K and vibrational temperatures in the range of 4200-6200 K. The vibrational and rotational temperatures increase slowly with increasing applied microwave field over the range of microwave fields investigated.

Hummelt, J. S.; Shapiro, M. A.; Temkin, R. J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2012-12-15T23:59:59.000Z

290

An improved Monte Carlo study of coherent scattering effects of low energy charged particle transport in Percus-Yevick liquids  

E-Print Network [OSTI]

We generalize a simple Monte Carlo (MC) model for dilute gases to consider the transport behavior of positrons and electrons in Percus-Yevick model liquids under highly non-equilibrium conditions, accounting rigorously for coherent scattering processes. The procedure extends an existing technique [Wojcik and Tachiya, Chem. Phys. Lett. 363, 3--4 (1992)], using the static structure factor to account for the altered anisotropy of coherent scattering in structured material. We identify the effects of the approximation used in the original method, and develop a modified method that does not require that approximation. We also present an enhanced MC technique that has been designed to improve the accuracy and flexibility of simulations in spatially-varying electric fields. All of the results are found to be in excellent agreement with an independent multi-term Boltzmann equation solution, providing benchmarks for future transport models in liquids and structured systems.

Tattersall, W J; Boyle, G J; White, R D

2015-01-01T23:59:59.000Z

291

Plasma Nanoscience: from Nano-Solids in Plasmas to Nano-Plasmas in Solids  

E-Print Network [OSTI]

The unique plasma-specific features and physical phenomena in the organization of nanoscale solid-state systems in a broad range of elemental composition, structure, and dimensionality are critically reviewed. These effects lead to the possibility to localize and control energy and matter at nanoscales and to produce self-organized nano-solids with highly unusual and superior properties. A unifying conceptual framework based on the control of production, transport, and self-organization of precursor species is introduced and a variety of plasma-specific non-equilibrium and kinetics-driven phenomena across the many temporal and spatial scales is explained. When the plasma is localized to micrometer and nanometer dimensions, new emergent phenomena arise. The examples range from semiconducting quantum dots and nanowires, chirality control of single-walled carbon nanotubes, ultra-fine manipulation of graphenes, nano-diamond, and organic matter, to nano-plasma effects and nano-plasmas of different states of matter...

Ostrikov, K; Meyyappan, M

2013-01-01T23:59:59.000Z

292

Electron energy distribution function control in gas discharge plasmas  

SciTech Connect (OSTI)

The formation of the electron energy distribution function (EEDF) and electron temperature in low temperature gas discharge plasmas is analyzed in frames of local and non-local electron kinetics. It is shown, that contrary to the local case, typical for plasma in uniform electric field, there is the possibility for EEDF modification, at the condition of non-local electron kinetics in strongly non-uniform electric fields. Such conditions “naturally” occur in some self-organized steady state dc and rf discharge plasmas, and they suggest the variety of artificial methods for EEDF modification. EEDF modification and electron temperature control in non-equilibrium conditions occurring naturally and those stimulated by different kinds of plasma disturbances are illustrated with numerous experiments. The necessary conditions for EEDF modification in gas discharge plasmas are formulated.

Godyak, V. A. [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA and RF Plasma Consulting, Brookline, Massachusetts (United States)] [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA and RF Plasma Consulting, Brookline, Massachusetts (United States)

2013-10-15T23:59:59.000Z

293

The Emergence of Consciousness in the Quantum Universe  

E-Print Network [OSTI]

It is argued that human consciousness is likely to have emerged during self-consistent evolution of the physical universe through the gradual accumulation of biological entities' ability to tap into the intrinsic non-deterministic potentiality during the global non-equilibrium phase transitions in the quantum universe. Due to the fact that the matter and energy content participating in the global phase transitions in the quantum universe is a continuum, there is in effect an infinite degrees-of-freedom in the substratum, which invalidates the usual deterministic laws of the mechanical evolution, and allows a chance factor to appear in the emergent properties of resonantly-formed quantum particles, especially in the acquired phases of their wave functions. Such chance factors, though occurring mostly randomly during the early cosmic evolution phase, can be harnessed more "purposefully" by the biological entities co-evolving with the physical universe, due in part to the globally entangled nature of quantum int...

Zhang, Xiaolei

2011-01-01T23:59:59.000Z

294

Ultrafast Electron Dynamics in Gold in the Presence of Laser Excited Surface Plasma Waves  

SciTech Connect (OSTI)

Surface plasmon excitation with ultrashort intense laser pulses enhances efficiently laser absorption in metals and creates local high fields and non-equilibrium hot electrons population that have attractivity for numerous applications such as the development of intense sources of high-energy particles or photons and in the fast ignitor scheme in the framework of inertial fusion. In this context, the knowledge of the dynamics of relaxation of the collective electrons behavior is of importance. Using gold grating, we have investigated electrons relaxation in the presence of laser excited surface plasmon waves using a multiple-wavelengh femtosecond pump-probe technique. The results yield evidence of longer relaxation time in the presence of the collective excitation than that of individual electronic states.

Raynaud, M. [CEA/DSM/IRAMIS/LSI, Ecole Polytechnique, 91128 Palaiseau (France); Geoffroy, G.; Perdrix, M. [CEA/DSM/IRAMIS/SPAM, 91191 Gif-sur-Yvette (France); Martin, P. [CELIA, Universite Bordeaux 1-CEA-CNRS, 33405 Talence (France)

2010-02-02T23:59:59.000Z

295

Transport, Aharonov-Bohm, and Topological Effects in Graphene Molecular Junctions and Graphene Nanorings  

E-Print Network [OSTI]

The unique ultra-relativistic, massless, nature of electron states in two-dimensional extended graphene sheets, brought about by the honeycomb lattice arrangement of carbon atoms in two-dimensions, provides ingress to explorations of fundamental physical phenomena in graphene nanostructures. Here we explore the emergence of new behavior of electrons in atomically precise segmented graphene nanoribbons (GNRs) and graphene rings with the use of tight-binding calculations, non-equilibrium Green's function transport theory, and a newly developed Dirac continuum model that absorbs the valence-to-conductance energy gaps as position-dependent masses, including topological-in-origin mass-barriers at the contacts between segments. Through transport investigations in variable-width segmented GNRs with armchair, zigzag, and mixed edge terminations we uncover development of new Fabry-Perot-like interference patterns in segmented GNRs, a crossover from the ultra-relativistic massless regime, characteristic of extended gra...

Yannouleas, Constantine; Landman, Uzi

2015-01-01T23:59:59.000Z

296

Geometric universality of currents in an open network of interacting particles  

SciTech Connect (OSTI)

We discuss a non-equilibrium statistical system on a graph or network. Identical particles are injected, interact with each other, traverse, and leave the graph in a stochastic manner described in terms of Poisson rates, possibly dependent on time and instantaneous occupation numbers at the nodes of the graph. We show that under the assumption of the relative rates constancy, the system demonstrates a profound statistical symmetry, resulting in geometric universality of the particle currents statistics. The phenomenon applies broadly to many man-made and natural open stochastic systems, such as queuing of packages over internet, transport of electrons and quasi-particles in mesoscopic systems, and chains of reactions in bio-chemical networks. We illustrate the utility of the general approach using two enabling examples from the two latter disciplines.

Sinitsyn, Nikolai A [Los Alamos National Laboratory; Chernyak, Vladimir Y [Los Alamos National Laboratory; Chertkov, Michael [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

297

Introductory statistical mechanics for electron storage rings  

SciTech Connect (OSTI)

These lectures introduce the beam dynamics of electron-positron storage rings with particular emphasis on the effects due to synchrotron radiation. They differ from most other introductions in their systematic use of the physical principles and mathematical techniques of the non-equilibrium statistical mechanics of fluctuating dynamical systems. A self-contained exposition of the necessary topics from this field is included. Throughout the development, a Hamiltonian description of the effects of the externally applied fields is maintained in order to preserve the links with other lectures on beam dynamics and to show clearly the extent to which electron dynamics in non-Hamiltonian. The statistical mechanical framework is extended to a discussion of the conceptual foundations of the treatment of collective effects through the Vlasov equation.

Jowett, J.M.

1986-07-01T23:59:59.000Z

298

An empirical study on regional disparity of R&D in China  

Science Journals Connector (OSTI)

This paper aims to reveal the characteristics of spatial distribution and changing trend of regional R&D expenditure in China during 1998-2004. In doing so, the authors have analysed both regional total R&D expenditure and its two components, that is, governmental R&D and business R&D expenditures, by means of spatial concentration index, variation coefficient, Gini coefficient, etc. We found that: 1) regional total R&D expenditure has a constant spatial clustering during 1998-2004; 2) governmental R&D expenditure appears to be more agglomerative (than business R&D expenditure) with a tendency of spatial equilibrium; 3) while business R&D expenditure was initially less agglomerative, it is characterised with a tendency of more and more spatial non-equilibrium.

Shouhua Wei; Xianjun Li; Guisheng Wu

2010-01-01T23:59:59.000Z

299

Friction forces on phase transition fronts  

SciTech Connect (OSTI)

In cosmological first-order phase transitions, the microscopic interaction of the phase transition fronts with non-equilibrium plasma particles manifests itself macroscopically as friction forces. In general, it is a nontrivial problem to compute these forces, and only two limits have been studied, namely, that of very slow walls and, more recently, ultra-relativistic walls which run away. In this paper we consider ultra-relativistic velocities and show that stationary solutions still exist when the parameters allow the existence of runaway walls. Hence, we discuss the necessary and sufficient conditions for the fronts to actually run away. We also propose a phenomenological model for the friction, which interpolates between the non-relativistic and ultra-relativistic values. Thus, the friction depends on two friction coefficients which can be calculated for specific models. We then study the velocity of phase transition fronts as a function of the friction parameters, the thermodynamic parameters, and the amount of supercooling.

Mégevand, Ariel, E-mail: megevand@mdp.edu.ar [IFIMAR (CONICET–UNMdP), Departamento de Física, Facultad de Ciencias Exactas y Naturales, UNMdP, Deán Funes 3350, (7600) Mar del Plata (Argentina)

2013-07-01T23:59:59.000Z

300

Kinetic dielectric decrement revisited: phenomenology of finite ion concentrations  

E-Print Network [OSTI]

With the help of a recently developed non-equilibrium approach, we investigate the ionic strength dependence of the Hubbard--Onsager dielectric decrement. We compute the depolarization of water molecules caused by the motion of ions in sodium chloride solutions from the dilute regime (0.035 M) up close to the saturation concentration (4.24 M), and find that the kinetic decrement displays a strong nonmonotonic behavior, in contrast to the prediction of available models. We introduce a phenomenological modification of the Hubbard--Onsager continuum theory, that takes into account the screening due to the ionic cloud at mean field level, and, is able to describe the kinetic decrement at high concentrations including the presence of a pronounced minimum.

Marcello Sega; Sofia Kantorovich; Axel Arnold

2014-07-16T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Macroscopic approach to the Casimir friction force  

E-Print Network [OSTI]

The general formula is derived for the vacuum friction force between two parallel perfectly flat planes bounding two material media separated by a vacuum gap and moving relative to each other with a constant velocity $\\mathbf{v}$. The material media are described in the framework of macroscopic electrodynamics whereas the nonzero temperature and dissipation are taken into account by making use of the Kubo formulae from non-equilibrium statistical thermodynamics. The formula obtained provides a rigorous basis for calculation of the vacuum friction force within the quantum field theory methods in the condensed matter physics. The revealed $v$-dependence of the vacuum friction force proves to be the following: for zero temperature ($T=0$) it is proportional to $(v/c)^3$ and for $T>0$ this force is linear in $(v/c)$.

V. V. Nesterenko; A. V. Nesterenko

2014-03-13T23:59:59.000Z

302

SU(2s+1) symmetry and nonlinear dynamic equations of spin s magnets  

E-Print Network [OSTI]

The article is devoted to the description of dynamics of magnets with arbitrary spin on the basis of the Hamiltonian formalism. The relationship between the magnetic ordering and Poisson bracket subalgebras of the magnetic degrees of freedom for spin s=1/2; 1; 3/2 has been established. We have been obtained non-linear dynamic equations without damping for normal and degenerate non-equilibrium states of high-spin magnets with the properties of the SO(3), SU(4), SU(2)$\\times$SU(2), SU(3), SO(4), SO(5) symmetry of exchange interaction. The connection between models of the magnetic exchange energy and the Casimir invariants has been discussed.

M. Y. Kovalevsky; A. V. Glushchenko

2013-12-20T23:59:59.000Z

303

Spontaneous emission in a silicon charge qubit  

E-Print Network [OSTI]

The interaction between a qubit and its environment provides a channel for energy relaxation which has an energy-dependent timescale governed by the specific coupling mechanism. We measure the rate of inelastic decay in a Si MOS double quantum dot (DQD) charge qubit through sensing the charge state's response to non-adiabatic driving of its excited state population. The charge distribution is sensed remotely in the weak measurement regime. We extract emission rates down to kHz frequencies by measuring the variation of the non-equilibrium charge occupancy as a function of amplitude and dwell times between non-adiabatic pulses. Our measurement of the energy-dependent relaxation rate provides a fingerprint of the relaxation mechanism, indicating that relaxation rates for this Si MOS DQD are consistent with coupling to deformation acoustic phonons.

Khoi T. Nguyen; N. Tobias Jacobson; Michael P. Lilly; Nathaniel C. Bishop; Erik Nielsen; Joel R. Wendt; J. Dominguez; T. Pluym; Malcolm S. Carroll

2014-03-14T23:59:59.000Z

304

Noise Rectification and Fluctuations of an Asymmetric Inelastic Piston  

E-Print Network [OSTI]

We consider a massive inelastic piston, whose opposite faces have different coefficients of restitution, moving under the action of an infinitely dilute gas of hard disks maintained at a fixed temperature. The dynamics of the piston is Markovian and obeys a continuous Master Equation: however, the asymmetry of restitution coefficients induces a violation of detailed balance and a net drift of the piston, as in a Brownian ratchet. Numerical investigations of such non-equilibrium stationary state show that the velocity fluctuations of the piston are symmetric around the mean value only in the limit of large piston mass, while they are strongly asymmetric in the opposite limit. Only taking into account such an asymmetry, i.e. including a third parameter in addition to the mean and the variance of the velocity distribution, it is possible to obtain a satisfactory analytical prediction for the ratchet drift velocity.

G. Costantini; U. Marini Bettolo Marconi; A. Puglisi

2008-06-06T23:59:59.000Z

305

Spin transport and spin polarization properties in double-stranded DNA  

SciTech Connect (OSTI)

We study the spin-dependent electron transport through a double-stranded DNA (dsDNA) using the Bogoliubov-de Gennes equations and non-equilibrium Green's function method. We calculate the spin-dependent electron conductance and spin-polarization for different lengths, helix angles, twist angles of dsDNA, the environment-induced dephasing factors, and hopping integral. It is shown that the conductance decreases by increasing the length and dephasing factor. Also, we show that the spin-polarization depends on the helical symmetry and the length of DNA. It is shown that the double-stranded DNA can act as a perfect spin filter. Finally, we show that the sign of spin polarization can be inverted from +1 (?1) to ?1 (+1) for some values of hopping integral.

Simchi, Hamidreza, E-mail: simchi@iust.ac.ir [Department of Physics, Iran University of Science and Technology, Narrmak, Tehran 16844 (Iran, Islamic Republic of); Semiconductor Technology Center, Tehran (Iran, Islamic Republic of); Esmaeilzadeh, Mahdi, E-mail: mahdi@iust.ac.ir; Mazidabadi, Hossein [Department of Physics, Iran University of Science and Technology, Narrmak, Tehran 16844 (Iran, Islamic Republic of)

2013-11-21T23:59:59.000Z

306

Spin-dependent electron transport in zinc- and manganese-doped adenine molecules  

SciTech Connect (OSTI)

The spin-dependent electron transport properties of zinc- and manganese-doped adenine molecules connected to zigzag graphene leads are studied in the zero bias regime using the non-equilibrium Green's function method. The conductance of the adenine molecule increased and became spin-dependent when a zinc or manganese atom was doped into the molecules. The effects of a transverse electric field on the spin-polarization of the transmitted electrons were investigated and the spin-polarization was controlled by changing the transverse electric field. Under the presence of a transverse electric field, both the zinc- and manganese-doped adenine molecules acted as spin-filters. The maximum spin-polarization of the manganese-doped adenine molecule was greater than the molecule doped with zinc.

Simchi, Hamidreza, E-mail: simchi@iust.ac.ir [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of); Semiconductor Technology Center, Tehran 16844 (Iran, Islamic Republic of); Esmaeilzadeh, Mahdi, E-mail: mahdi@iust.ac.ir; Mazidabadi, Hossein [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of)

2014-01-28T23:59:59.000Z

307

A high-order harmonic generation apparatus for time- and angle-resolved photoelectron spectroscopy  

SciTech Connect (OSTI)

We present a table top setup for time- and angle-resolved photoelectron spectroscopy to investigate band structure dynamics of correlated materials driven far from equilibrium by femtosecond laser pulse excitation. With the electron-phonon equilibration time being in the order of 1–2 ps it is necessary to achieve sub-picosecond time resolution. Few techniques provide both the necessary time and energy resolution to map non-equilibrium states of the band structure. Laser-driven high-order harmonic generation is such a technique. In our experiment, a grating monochromator delivers tunable photon energies up to 40 eV. A photon energy bandwidth of 150 meV and a pulse duration of 100 fs FWHM allow us to cover the k-space necessary to map valence bands at different k{sub z} and detect outer core states.

Frietsch, B.; Gahl, C.; Teichmann, M.; Weinelt, M. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany)] [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Carley, R. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany) [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Döbrich, K. [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany)] [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Schwarzkopf, O.; Wernet, Ph. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2013-07-15T23:59:59.000Z

308

Thermodynamics of inequalities: from precariousness to economic stratification  

E-Print Network [OSTI]

Increasingly large social and economic inequalities are observed throughout the world. Theorists after Pareto have studied this phenomenon in terms of the tail structure of the wealth distribution at a given time. Unfortunately, this approach leaves unaddressed the dynamics of inequalities in non-equilibrium situations, e.g. under redistribution policies. Here we introduce a thermodynamical theory of inequalities based on the analogy between economic stratification and statistical entropy. Within this framework we identify the combination of upward mobility with precariousness as a fundamental driver of inequality. We formalize this statement by a "second-law" inequality constraining the growth of inequalities over time. Our method can be generalized to gain insight into the dynamics of inequalities in any Markovian model of socioeconomic interactions.

Smerlak, Matteo

2014-01-01T23:59:59.000Z

309

Exploring the mechanisms of protein folding  

E-Print Network [OSTI]

Neither of the two prevalent theories, namely thermodynamic stability and kinetic stability, provides a comprehensive understanding of protein folding. The thermodynamic theory is misleading because it assumes that free energy is the exclusive dominant mechanism of protein folding, and attributes the structural transition from one characteristic state to another to energy barriers. Conversely, the concept of kinetic stability overemphasizes dominant mechanisms that are related to kinetic factors. This article explores the stability condition of protein structures from the viewpoint of meso-science, paying attention to the compromise in the competition between minimum free energy and other dominant mechanisms. Based on our study of complex systems, we propose that protein folding is a meso-scale, dissipative, nonlinear and non-equilibrium process that is dominated by the compromise between free energy and other dominant mechanisms such as environmental factors. Consequently, a protein shows dynamic structures,...

Xu, Ji; Ren, Ying; Li, Jinghai

2013-01-01T23:59:59.000Z

310

Statistical charge distribution over dust particles in a non-Maxwellian Lorentzian plasma  

SciTech Connect (OSTI)

On the basis of statistical mechanics and charging kinetics, the charge distribution over uniform size spherical dust particles in a non-Maxwellian Lorentzian plasma is investigated. Two specific situations, viz., (i) the plasma in thermal equilibrium and (ii) non-equilibrium state where the plasma is dark (no emission) or irradiated by laser light (including photoemission) are taken into account. The formulation includes the population balance equation for the charged particles along with number and energy balance of the complex plasma constituents. The departure of the results for the Lorentzian plasma, from that in case of Maxwellian plasma, is graphically illustrated and discussed; it is shown that the charge distribution tends to results corresponding to Maxwellian plasma for large spectral index. The charge distribution predicts the opposite charging of the dust particles in certain cases.

Mishra, S. K. [Institute for Plasma Research (IPR), Gandhinagar-382428 (India); Misra, Shikha, E-mail: shikhamish@gmail.com [Centre for Energy Studies (CES), Indian Institute of Technology Delhi (IITD), New Delhi-110016 (India)

2014-07-15T23:59:59.000Z

311

Thermodynamic Behavior of particular $f(R,T)$ Gravity Models  

E-Print Network [OSTI]

We investigate the thermodynamics at the apparent horizon of the FRW universe in $f(R,T)$ theory under non-equilibrium description. The laws of thermodynamics have been discussed for two particular models of $f(R,T)$ theory. The first law of thermodynamics is expressed in the form of Clausius relation $T_hd\\hat{S}_h=\\delta{Q}$, where $\\delta{Q}=-d\\hat{E}+Wd\\mathbb{V}+T_hd_{\\jmath}\\hat{S}$ is the energy flux across the horizon and $d_{\\jmath}\\hat{S}$ is the entropy production term. Furthermore, the conditions to preserve the generalized second law of thermodynamics are established with the constraints of positive temperature and attractive gravity. We have illustrated our results for some concrete models in this theory.

Sharif, M

2014-01-01T23:59:59.000Z

312

The generalized second law of thermodynamics in generalized gravity theories  

E-Print Network [OSTI]

We investigate the generalized second law of thermodynamics (GSL) in generalized theories of gravity. We examine the total entropy evolution with time including the horizon entropy, the non-equilibrium entropy production, and the entropy of all matter, field and energy components. We derive a universal condition to protect the generalized second law and study its validity in different gravity theories. In Einstein gravity, (even in the phantom-dominated universe with a Schwarzschild black hole), Lovelock gravity, and braneworld gravity, we show that the condition to keep the GSL can always be satisfied. In $f(R)$ gravity and scalar-tensor gravity, the condition to protect the GSL can also hold because the gravity is always attractive and the effective Newton constant should be approximate constant satisfying the experimental bounds.

Shao-Feng Wu; Bin Wang; Guo-Hong Yang; Peng-Ming Zhang

2008-01-17T23:59:59.000Z

313

Generalized Second Law of Thermodynamics for FRW Cosmology with Power-Law Entropy Correction  

E-Print Network [OSTI]

In this work, we have considered the power law correction of entropy on the horizon. If the flat FRW Universe is filled with the n components fluid with interactions, the GSL of thermodynamics for apparent and event horizons have been investigated for equilibrium and non-equilibrium cases. If we consider a small perturbation around the de Sitter space-time, the general conditions of the validity of GSL have been found. Also if a phantom dominated Universe has a polelike type scale factor, the validity of GSL has also been analyzed. Further we have obtained constraints on the power-law parameter {\\alpha} in the phantom and quintessence dominated regimes. Finally we obtain conditions under which GSL breaks down in a cosmological background.

Ujjal Debnath; Surajit Chattopadhyay; Ibrar Hussain; Mubasher Jamil; Ratbay Myrzakulov

2011-11-15T23:59:59.000Z

314

Second Law of Thermodynamics and Macroscopic Observables within Boltzmann's principle, an attempt  

E-Print Network [OSTI]

Boltzmann's principleS=k*ln W is generalized to non-equilibrium Hamiltonian systems with possibly fractal distributions in phase space by the box-counting volume. The probabilities P(M) of macroscopic observables M are given by the ratio P(M)=W(M)/W of these volumes of the sub-manifold {M} of the microcanonical ensemble with the constraint M to the one without. With this extension of the phase-space integral the Second Law is derived without invoking the thermodynamic limit. The irreversibility in this approach is due to the replacement of the phase space volume of the possibly fractal sub-manifold {M} by the volume of the closure of {M}. In contrast to conventional coarse graining the box-counting volume is defined by the limit of infinite resolution.

D. H. E. Gross

2000-11-08T23:59:59.000Z

315

Gravitationally Induced Particle Production: Thermodynamics and Kinetic Theory  

E-Print Network [OSTI]

A relativistic kinetic description for the irreversible thermodynamic process of gravitationally induced particle production is proposed in the context of an expanding Friedmann-Robertson-Walker (FRW) geometry. We show that the covariant thermodynamic treatment referred to as "adiabatic" particle production provoked by the cosmic time-varying gravitational field has a consistent kinetic counterpart. The variation of the distribution function is associated to a non-collisional kinetic term of quantum-gravitational origin which is proportional to the ratio $\\Gamma/H$, where $\\Gamma$ is the gravitational particle production rate and H is the Hubble parameter. For $\\Gamma << H$ the process is negligible and as should be expected it also vanishes (regardless of the value of $\\Gamma$) in the absence of gravitation. The resulting non-equilibrium distribution function has the same functional form of equilibrium with the evolution laws corrected by the particle production process. The macroscopic temperature evo...

Lima, J A S

2014-01-01T23:59:59.000Z

316

Micro-canonical thermodynamics: Why does heat flow from hot to cold  

E-Print Network [OSTI]

We show how to use a central limit approximation for additive co-cycles to describe non-equilibrium and far from equilibrium thermodynamic behavior. We consider first two weakly coupled Hamiltonian dynamical systems initially at different micro-canonical temperatures. We describe a stochastic model where the energy-transfer between the two systems is considered as a random variable satisfying a central limit approximation. We show that fluctuations in energy observables are linearly related to the heat-transfer (dissipation). As a result, on average, heat flows from hot to cold. We also consider the far from equilibrium situation of a non-Hamiltonian thermostatted system as in Evans et al. {\\em Phys.\\ Rev.\\ Lett.} {\\bf 71}, 2401 (1993). Applying the same central limit approximation we re-derive their relation for the violation of the 2nd law of thermodynamics. We note that time-reversal symmetry is not used in our derivation.

Hans Henrik Rugh

2012-04-10T23:59:59.000Z

317

Spin injection and filtering in halfmetal/semiconductor (CrAs/GaAs) heterostructures  

SciTech Connect (OSTI)

Theoretical investigations of spin-dependent transport in GaAS/CrAs/GaAs halfmetal-semiconductor heterostructures indicate that this system is a candidate for an efficient room temperature spin injector and filter. The spin dependent electronic structure of zincblende CrAs and the band offset between GaAs and CrAs are determined by ab-initio calculations within the method of linear muffin tin orbitals (LMTO). This band structure is mapped onto an effective sp{sup 3}d{sup 5}s* nearest neighbor tight-binding (TB) Hamiltonian and the steady-state transport characteristic is calculated within a non-equilibrium Green’s function approach. Even at room temperature we find current spin polarizations up to 97%.

Stickler, B. A.; Ertler, C.; Pötz, W. [Institute of Physics, Karl-Franzens Universität Graz (Austria); Chioncel, L. [Institute of Physics, Universität Augsburg (Germany); Arrigoni, E. [Institute of Theoretical and Computational Physics, TU Graz (Austria)

2013-12-04T23:59:59.000Z

318

Characterization and applications of nanofiltration membranes: State of the art  

Science Journals Connector (OSTI)

There is a voluminous literature on the determination of structural and electrical properties of a nanofiltration (NF) membrane and its separation performance. Theories used to characterize a NF membrane usually include: the non-equilibrium thermodynamic model, the pore model, the TMS model, the electrostatic and steric-hindrance pore model, and the semi-emprical model. In the article, we briefly trace the origins or the general ideas of the above-mentioned theories. From there, recent researches on the evaluation of membrane structural and electrical properties are reviewed. We then turn to research on the separation performance of a NF membrane for single component solutions of inorganic electrolytes, neutral organic solutions, and mixture solution of inorganic electrolytes or that of electrolyte and neutral organic solute. Finally, we conclude with suggestions as to the role of models in the contributions to the application of the NF technology in product separation processes.

Xiao-Lin Wang; Wei-Juan Shang; Da-Xin Wang; Ling Wu; Cong-Hui Tu

2009-01-01T23:59:59.000Z

319

Shock formation in the collapse of a vapor nano-bubble  

E-Print Network [OSTI]

In this paper a diffuse-interface model featuring phase change, transition to supercritical conditions, thermal conduction, compressibility effects and shock wave propagation is exploited to deal with the dynamics of a cavitation bubble. At variance with previous descriptions, the model is uniformly valid for all phases (liquid, vapor and supercritical) and phase transitions involved, allowing to describe the non-equilibrium processes ongoing during the collapse. As consequence of this unitary description, rather unexpectedly for pure vapor bubbles, the numerical experiments show that the collapse is accompanied by the emission of a strong shock wave in the liquid and by the oscillation of the bubble that periodically disappears and reappears, due to transition to super/sub critical conditions. The mechanism of shock wave formation is strongly related to the transition of the vapor to supercritical state, with a progressive steepening of the compression wave to form the shock which is eventually reflected as ...

Magaletti, Francesco; Casciola, Carlo Massimo

2014-01-01T23:59:59.000Z

320

A density-independent glass transition in biological tissues  

E-Print Network [OSTI]

Cells must move through tissues in many important biological processes, including embryonic development, cancer metastasis, and wound healing. In these tissues, a cell's motion is often strongly constrained by its neighbors, leading to glassy dynamics. Recent work has demonstrated the existence of a non-equilibrium glass transition in self-propelled particle models for active matter, where the transition is driven by changes in density. However, this may not explain liquid-to-solid transitions in confluent tissues, where there are no gaps between cells and the packing fraction remains fixed and equal to unity. Here we demonstrate the existence of a different type of glass transition that occurs in the well-studied vertex model for confluent tissue monolayers. In this model, the onset of rigidity is governed by changes to single-cell properties such as cell-cell adhesion, cortical tension, and volume compressibility, providing an explanation for a liquid-to-solid transitions in confluent tissues.

Bi, Dapeng; Schwarz, J M; Manning, M Lisa

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gc5 non-equilibrium brn" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

LHC Physics and Cosmology  

E-Print Network [OSTI]

In these Lectures I review possible constraints on particle physics models, obtained by means of combining the results of collider measurements with astrophysical data. I emphasize the theoretical-model dependence of these results. I discuss supersymmetric dark matter constraints at colliders (mainly LHC) in various theoretical contexts: the standard Cosmological-Constant-Cold-Dark-Matter (Lambda-CDM) model, (super)string-inspired ones and non-equilibrium relaxation dark energy models. I then investigate the capability of LHC measurements in asserting whether supersymmetric matter (if discovered) constitutes part, or all, of the astrophysical dark matter. I also discuss prospects for improving the constraints in future precision facilities, such as the International Linear Collider.

Nikolaos E. Mavromatos

2007-08-01T23:59:59.000Z

322

Differential Resistance of Two Dimensional Electron Systems Subject to Microwave Radiation  

SciTech Connect (OSTI)

We present the expression for differential resistance of a disordered two-dimensional electron gas placed in a perpendicular magnetic field and subject to microwave irradiation. We demonstrate that in strong dc electric fields the current oscillates as a function of the strength of the applied constant electric field. We demonstrate that the amplitude of oscillations of the differential resistivity is characterized by the back-scattering rate off disorder. We argue that the dominant contribution to the non-linearity in strong electric fields originates from the modification of electron scattering off disorder by electric fields, or so-called 'displacement' mechanism. The non-equilibrium mechanism, which is related to modification of electron distribution function by electric fields turns out to be inefficient in strong electric fields, although it describes current in weak electric fields. We further analyze the positions of maxima and minima of the differential resistance as a function of the applied electric field and frequency of microwave radiation.

Khodas, M.; Vavilov, M.G.

2008-11-03T23:59:59.000Z

323

CX-004918: Categorical Exclusion Determination | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

8: Categorical Exclusion Determination 8: Categorical Exclusion Determination CX-004918: Categorical Exclusion Determination Sheetak -Non-Equilibrium Asymmetric Thermoelectric Devices CX(s) Applied: B3.6 Date: 08/10/2010 Location(s): Austin, Texas Office(s): Advanced Research Projects Agency - Energy Funding will support bench-scale research and development on a novel thermoelectric device for use in various air conditioning applications. The proposed work is consistent with the goals of Building Energy Efficiency Through Innovative Thermodevices: the development of energy efficient cooling technologies and air conditioners for buildings, to save energy and reduce greenhouse gas emissions. Proposed work consists entirely of research, development, and demonstration work to be completed in Sheetak's

324

Kovacs-like memory effect in driven granular gases  

E-Print Network [OSTI]

While memory effects have been reported for dense enough disordered systems such as glasses, we show here by a combination of analytical and simulation techniques that they are also intrinsic to the dynamics of dilute granular gases. By means of a certain driving protocol, we prepare the gas in a state where the granular temperature $T$ coincides with its long time limit. However, $T$ does not subsequently remain constant, but exhibits a non-monotonic evolution before reaching its non-equilibrium steady value. The corresponding so-called Kovacs hump displays a normal behavior for weak dissipation (as observed in molecular systems), but is reversed under strong dissipation, where it thus becomes anomalous.

A. Prados; E. Trizac

2014-04-24T23:59:59.000Z

325

Memory effect in uniformly heated granular gases  

E-Print Network [OSTI]

We evidence a Kovacs-like memory effect in a uniformly driven granular gas. A system of inelastic hard particles, in the low density limit, can reach a non-equilibrium steady state when properly forced. By following a certain protocol for the drive time dependence, we prepare the gas in a state where the granular temperature coincides with its long time value. The temperature subsequently does not remain constant, but exhibits a non-monotonic evolution with either a maximum or a minimum, depending on the dissipation, and on the protocol. We present a theoretical analysis of this memory effect, at Boltzmann-Fokker-Planck equation level, and show that when dissipation exceeds a threshold, the response can be coined anomalous. We find an excellent agreement between the analytical predictions and direct Monte Carlo simulations.

E. Trizac; A. Prados

2014-07-15T23:59:59.000Z

326

ABAKO/RAPCAL: A Flexible Computational Package to Perform Radiative Properties Calculations and Diagnostics in a Wide Range of Plasma Conditions  

SciTech Connect (OSTI)

This work describes ABAKO/RAPCAL, a flexible computational package for the study of population kinetics and radiative properties of non-equilibrium plasmas in a wide range of physical conditions. The code was developed looking for an optimal compromise between accuracy and computational cost. ABAKO/RAPCAL assembles a set of simple analytical models which yield substantial savings of computer resources, but yet still providing good comparisons with more elaborated codes and experimental data. Here we present some results to show the ABAKO/RAPCAL capabilities to calculate the charge distribution and radiative properties of both low- and high-Z plasmas. Finally, an application for K-shell spectroscopic determination of the electron temperature and density of laser-produced plasmas is also shown.

Florido, R.; Rodriguez, R.; Gil, J. M.; Rubiano, J. G.; Martel, P. [Departamento de Fisica, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria (Spain); Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Minguez, E. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Sauvan, R. [Departamento de Ingenieria Energetica, UNED, Madrid (Spain); Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Mancini, R. [Department of Physics, University of Nevada, Reno, NV 89557 (United States)

2008-10-22T23:59:59.000Z

327

Third-generation cylindrical dendrimers based on L-aspargic acid in solutions: hydrodynamic and electrooptical properties  

E-Print Network [OSTI]

Samples of third-generation cylindrical dendrimers with molar masses ranging in the interval 20000...60000 have been studied by the methods of equilibrium and non-equilibrium electrical birefringence, molecular hydrodynamics and optics. It was found that the absolute values of Kerr and flow birefringence constants exceed the values obtained for analogous dendrimers of lower generations. The mechanism of reorientation has proven to be strongly dependent on the physical and chemical properties of the solvent. In chloroform solutions, the studied dendrimers align to the microwave-frequency electric fields according to large-scale mechanism. In dichloroacetic acid solutions, the observed reorientation mechanism is low-scale, which is explained by degradation of intermolecular hydrogen bonds. Terminal dendritic substituents of the macromolecules have experimentally proven to be oriented mainly along the primary polymer chain.

Ilya Martchenko; Nikolai Tsvetkov

2008-09-23T23:59:59.000Z

328

Theoretical investigation of thermophysical properties in two-temperature argon-helium thermal plasma  

Science Journals Connector (OSTI)

The thermophysical properties of argon-helium thermal plasma have been studied in the temperature range from 5000 to 40 000 K at atmospheric pressure in local thermodynamic equilibrium and non-local thermodynamic equilibrium conditions. Two cases of thermal plasma considered are (i) ground state plasma in which all the atoms and ions are assumed to be in the ground state and (ii) excited stateplasma in which atoms and ions are distributed over various possible excited states. The influence of electronic excitation and non-equilibrium parameter ??=?Te/Th on thermodynamic properties (composition degree of ionization Debye length enthalpy and total specific heat) and transport properties(electrical conductivity electron thermal conductivity and thermal diffusion ratio) have been studied. Within the framework of Chapman-Enskog method the higher-order contributions to transport coefficient and their convergence are studied. The influence of different molar compositions of argon-helium plasma mixture on convergence of higher-orders is investigated. Furthermore the effect of different definitions of Debye length has also been examined for electrical conductivity and it is observed that electrical conductivity with the definition of Debye length (in which only electrons participate in screening) is less than that of the another definition (in which both the electrons and ions participate in screening) and this deviation increases with electron temperature. Finally the effect of lowering of ionization energy is examined on electron number density Debye length and higher-order contribution to electrical conductivity. It is observed that the lowering of the ionization energy affects the electron transport-properties and consequently their higher-order contributions depending upon the value of the non-equilibrium parameter ?.

Rohit Sharma; Gurpreet Singh; Kuldip Singh

2011-01-01T23:59:59.000Z

329

Theoretical investigation of thermophysical properties in two-temperature argon-helium thermal plasma  

SciTech Connect (OSTI)

The thermophysical properties of argon-helium thermal plasma have been studied in the temperature range from 5000 to 40 000 K at atmospheric pressure in local thermodynamic equilibrium and non-local thermodynamic equilibrium conditions. Two cases of thermal plasma considered are (i) ground state plasma in which all the atoms and ions are assumed to be in the ground state and (ii) excited state plasma in which atoms and ions are distributed over various possible excited states. The influence of electronic excitation and non-equilibrium parameter {theta} = T{sub e}/T{sub h} on thermodynamic properties (composition, degree of ionization, Debye length, enthalpy, and total specific heat) and transport properties (electrical conductivity, electron thermal conductivity, and thermal diffusion ratio) have been studied. Within the framework of Chapman-Enskog method, the higher-order contributions to transport coefficient and their convergence are studied. The influence of different molar compositions of argon-helium plasma mixture on convergence of higher-orders is investigated. Furthermore, the effect of different definitions of Debye length has also been examined for electrical conductivity and it is observed that electrical conductivity with the definition of Debye length (in which only electrons participate in screening) is less than that of the another definition (in which both the electrons and ions participate in screening) and this deviation increases with electron temperature. Finally, the effect of lowering of ionization energy is examined on electron number density, Debye length, and higher-order contribution to electrical conductivity. It is observed that the lowering of the ionization energy affects the electron transport-properties and consequently their higher-order contributions depending upon the value of the non-equilibrium parameter {theta}.

Sharma, Rohit; Singh, Kuldip [Department of Physics, Guru Nanak Dev University, Amritsar (India); Singh, Gurpreet [Department of Physics, DAV College, Bathinda (India)

2011-08-15T23:59:59.000Z

330

Large dynamic range diagnostics for high current electron LINACs  

SciTech Connect (OSTI)

The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

Evtushenko, Pavel [JLAB

2013-11-01T23:59:59.000Z

331

Large dynamic range diagnostics for high current electron LINACs  

SciTech Connect (OSTI)

The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

Evtushenko, P., E-mail: Pavel.Evtushenko@jlab.org [Thomas Jefferson National Accelerator Facility 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2013-11-07T23:59:59.000Z

332

Simulations of Turbulent Flows with Strong Shocks and Density Variations  

SciTech Connect (OSTI)

In this report, we present the research efforts made by our group at UCLA in the SciDAC project ���¢��������Simulations of turbulent flows with strong shocks and density variations���¢�������. We use shock-fitting methodologies as an alternative to shock-capturing schemes for the problems where a well defined shock is present. In past five years, we have focused on development of high-order shock-fitting Navier-Stokes solvers for perfect gas flow and thermochemical non-equilibrium flow and simulation of shock-turbulence interaction physics for very strong shocks. Such simulation has not been possible before because the limitation of conventional shock capturing methods. The limitation of shock Mach number is removed by using our high-order shock-fitting scheme. With the help of DOE and TeraGrid/XSEDE super computing resources, we have obtained new results which show new trends of turbulence statistics behind the shock which were not known before. Moreover, we are also developing tools to consider multi-species non-equilibrium flows. The main results are in three areas: (1) development of high-order shock-fitting scheme for perfect gas flow, (2) Direct Numerical Simulation (DNS) of interaction of realistic turbulence with moderate to very strong shocks using super computing resources, and (3) development and implementation of models for computation of mutli-species non-quilibrium flows with shock-fitting codes.

Zhong, Xiaolin

2012-12-13T23:59:59.000Z

333

Large-deviation principles, stochastic effective actions, path entropies, and the structure and meaning of thermodynamic descriptions  

E-Print Network [OSTI]

The meaning of thermodynamic descriptions is found in large-deviations scaling of the fluctuations probabilities. The primary large-deviations rate function is the entropy, which is the basis for both fluctuation theorems and for characterizing the thermodynamic interactions of systems. Freidlin-Wentzell theory provides a general formulation of large-deviations scaling for non-equilibrium stochastic processes, through a representation in terms of a Hamiltonian dynamical system. A number of related methods now exist to construct the Freidlin-Wentzell Hamiltonian for many kinds of stochastic processes; one method due to Doi and Peliti, appropriate to integer counting statistics, is widely used in reaction-diffusion theory. Using these tools together with a path-entropy method due to Jaynes, we show how to construct entropy functions that both express large-deviations scaling of fluctuations, and describe system-environment interactions, for discrete stochastic processes either at or away from equilibrium. A collection of variational methods familiar within quantum field theory, but less commonly applied to the Doi-Peliti construction, is used to define a "stochastic effective action", which is the large-deviations rate function for arbitrary non-equilibrium paths. We show how common principles of entropy maximization, applied to different ensembles of states or of histories, lead to different entropy functions and different sets of thermodynamic state variables. Yet the relations of among all these levels of description may be constructed explicitly and understood in terms of information conditions. The example systems considered introduce methods that may be used to systematically construct descriptions with all the features familiar from equilibrium thermodynamics, for a much wider range of systems describable by stochastic processes.

Eric Smith

2011-02-18T23:59:59.000Z

334

Dissipation of Modified Entropic Gravitational Energy Through Gravitational Waves  

E-Print Network [OSTI]

The phenomenological nature of a new gravitational type interaction between two different bodies derived from Verlinde's entropic approach to gravitation in combination with Sorkin's definition of Universe's quantum information content, is investigated. Assuming that the energy stored in this entropic gravitational field is dissipated under the form of gravitational waves and that the Heisenberg principle holds for this system, one calculates a possible value for an absolute minimum time scale in nature $\\tau=15/16 \\frac{\\Lambda^{1/2}\\hbar G}{c^4}\\sim9.27\\times10^{-105}$ seconds, which is much smaller than the Planck time $t_{P}=(\\hbar G/c^5)^{1/2}\\sim 5.38\\times10^{-44}$ seconds. This appears together with an absolute possible maximum value for Newtonian gravitational forces generated by matter $F_g=32/30\\frac{c^7}{\\Lambda \\hbar G^2}\\sim 3.84\\times 10^{165}$ Newtons, which is much higher than the gravitational field between two Planck masses separated by the Planck length $F_{gP}=c^4/G\\sim1.21\\times10^{44}$ Newtons.

Clovis Jacinto de Matos

2011-11-04T23:59:59.000Z

335

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type structures, which are orthorhombic are attributed to the ordering of oxygen vacancies. The cubic to orthorhombic transitions leads to 2.6% increase in strains and thus residual stresses generated could influence the fracture behavior of the OTM membrane. Continued investigations on the thermodynamic properties (stability and phase-separation behavior) and total conductivity of prototype membrane materials were carried out. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previously characterization, stoichiometry and conductivity measurements for samples of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were reported. In this report, measurements of the chemical and thermal expansion as a function of temperature and p{sub O2} are described.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

336

Exposure to As, Cd and Pb-mixture impairs myelin and axon development in rat brain, optic nerve and retina  

SciTech Connect (OSTI)

Arsenic (As), lead (Pb) and cadmium (Cd) are the major metal contaminants of ground water in India. We have reported the toxic effect of their mixture (metal mixture, MM), at human relevant doses, on developing rat astrocytes. Astrocyte damage has been shown to be associated with myelin disintegration in CNS. We, therefore, hypothesized that the MM would perturb myelinating white matter in cerebral cortex, optic nerve (O.N.) and retina. We observed modulation in the levels of myelin and axon proteins, such as myelin basic protein (MBP), proteolipid protein, 2?-, 3?-cyclic-nucleotide-3?-phosphodiesterase, myelin-associated glycoprotein and neurofilament (NF) in the brain of developing rats. Dose and time-dependent synergistic toxic effect was noted. The MBP- and NF-immunolabeling, as well as luxol-fast blue (LFB) staining demonstrated a reduction in the area of intact myelin-fiber, and an increase in vacuolated axons, especially in the corpus-callosum. Transmission electron microscopy (TEM) of O.N. revealed a reduction in myelin thickness and axon-density. The immunolabeling with MBP, NF, and LFB staining in O.N. supported the TEM data. The hematoxylin and eosin staining of retina displayed a decrease in the thickness of nerve-fiber, plexiform-layer, and retinal ganglion cell (RGC) count. Investigating the mechanism revealed a loss in glutamine synthetase activity in the cerebral cortex and O.N., and a fall in the brain derived neurotrophic factor in retina. An enhanced apoptosis in MBP, NF and Brn3b-containing cells justified the diminution in myelinating axons in CNS. Our findings for the first time indicate white matter damage by MM, which may have significance in neurodevelopmental-pediatrics, neurotoxicology and retinal-cell biology. - Highlights: • As, Cd and Pb-mixture, at human relevant dose, demyelinate developing rat CNS. • The attenuation in myelin and axon is synergistic. • The optic nerve and brain demonstrate reduced glutamine synthetase. • The retina exhibits diminished neurotrophin levels and cellular differentiation. • The toxic effect is apoptotic.

Rai, Nagendra Kumar; Ashok, Anushruti [Academy of Scientific and Innovative Research (India); Developmental Toxicology, Council of Scientific and Industrial Research-Indian Institute of Toxicology Research (CSIR-IITR) (India); Rai, Asit; Tripathi, Sachin [Developmental Toxicology, Council of Scientific and Industrial Research-Indian Institute of Toxicology Research (CSIR-IITR) (India); Nagar, Geet Kumar [Endocrinology, CSIR-Central Drug Research Institute (CSIR-CDRI) (India); Mitra, Kalyan [Electron Microscopy Unit, CSIR-CDRI, Lucknow 226001 (India); Bandyopadhyay, Sanghamitra, E-mail: sanghmitra@iitr.res.in [Academy of Scientific and Innovative Research (India); Developmental Toxicology, Council of Scientific and Industrial Research-Indian Institute of Toxicology Research (CSIR-IITR) (India)

2013-12-01T23:59:59.000Z

337

approved_list  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2-Sep-2000 2-Sep-2000 Exp # Spokesperson Title Days 634-2 Freedman Study of the 8B Neutrino Spectrum Through the 8B(b+)8Be(2a) Decay Chain-II 4 767-3 Rehm Decay Properties of Particle-Unbound States in 19Ne-III 4 827-2 Mueller Study of Unstable Osmium Nuclei by Coulomb Excitation 4 863X-2 Reviol Measurement of Evaporation Residues in the 40Ca+150Sm Reaction 2 876 Romoli Measurement of 17F Breakup Cross Section at the Barrier 4 877 Davids Drip-Line Decay Studies Around A = 76 5 879 Charity Non-Equilibrium Neutron Emission in Ni + Mo Reactions 5 880X Heinz Preparations Toward a Search for Super-Heavy Elements at ATLAS: Phase I 5 881 Kondev Radiative Capture and Fusion Dynamics in Cold Fusion 90Zr + 92Mo Reaction 7 882 Doyle Measurement of 3He to 4He Ratios in Isotopically Purified Helium 6 884 Miller

338

Materials Science and Engineering  

Broader source: Energy.gov (indexed) [DOE]

Materials Science and Engineering Materials Science and Engineering 1 Fe---Cr A lloys f or A dvanced N uclear E nergy A pplica9ons Ron S canon---equilibrium solutes introduced by mechanical alloying can segregate to grain b oundaries, p roducing

339

Pattern formation of dipolar colloids in rotating fields: Layering and synchronization  

E-Print Network [OSTI]

We report Brownian dynamics (BD) simulation and theoretical results for a system of spherical colloidal particles with permanent dipole moments in a rotating magnetic field. Performing simulations at a fixed packing fraction and dipole coupling parameter, we construct a full non-equilibrium phase diagram as function of the driving frequency ($\\omega_0$) and field strength ($B_0$). This diagram contains both synchronized states, where the individual particles follow the field with (on average) constant phase difference, and asynchronous states. The synchronization is accompanied by layer formation, i.e. by spatial symmetry-breaking, similar to systems of induced dipoles in rotating fields. In the permanent-dipole case, however, too large $\\omega_0$ yield a breakdown of layering, supplemented by complex changes of the single-particle rotational dynamics from synchronous to asynchronous behavior. We show that the limit frequencies $\\omega_c$ can be well described as a bifurcation in the nonlinear equation of motion of a single particle rotating in a viscous medium. Finally, we present a simple density functional theory, which describes the emergence of layers in perfectly synchronized states as an equilibrium phase transition.

Sebastian Jaeger; Sabine H. L. Klapp

2011-03-04T23:59:59.000Z

340

Numerical analysis of hydrogen production via methane steam reforming in porous media solar thermochemical reactor using concentrated solar irradiation as heat source  

Science Journals Connector (OSTI)

Abstract The calorific value of syngas can be greatly upgraded during the methane steam reforming process by using concentrated solar energy as heat source. In this study, the Monte Carlo Ray Tracing (MCRT) and Finite Volume Method (FVM) coupling method is developed to investigate the hydrogen production performance via methane steam reforming in porous media solar thermochemical reactor which includes the mass, momentum, energy and irradiative transfer equations as well as chemical reaction kinetics. The local thermal non-equilibrium (LTNE) model is used to provide more temperature information. The modified P1 approximation is adopted for solving the irradiative heat transfer equation. The MCRT method is used to calculate the sunlight concentration and transmission problems. The fluid phase energy equation and transport equations are solved by Fluent software. The solid phase energy equation, irradiative transfer equation and chemical reaction kinetics are programmed by user defined functions (UDFs). The numerical results indicate that concentrated solar irradiation on the fluid entrance surface of solar chemical reactor is highly uneven, and temperature distribution has significant influence on hydrogen production.

Fuqiang Wang; Jianyu Tan; Yong Shuai; Liang Gong; Heping Tan

2014-01-01T23:59:59.000Z

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341

Synchronization in Complex Oscillator Networks and Smart Grids  

SciTech Connect (OSTI)

The emergence of synchronization in a network of coupled oscillators is a fascinating topic in various scientific disciplines. A coupled oscillator network is characterized by a population of heterogeneous oscillators and a graph describing the interaction among them. It is known that a strongly coupled and sufficiently homogeneous network synchronizes, but the exact threshold from incoherence to synchrony is unknown. Here we present a novel, concise, and closed-form condition for synchronization of the fully nonlinear, non-equilibrium, and dynamic network. Our synchronization condition can be stated elegantly in terms of the network topology and parameters, or equivalently in terms of an intuitive, linear, and static auxiliary system. Our results significantly improve upon the existing conditions advocated thus far, they are provably exact for various interesting network topologies and parameters, they are statistically correct for almost all networks, and they can be applied equally to synchronization phenomena arising in physics and biology as well as in engineered oscillator networks such as electric power networks. We illustrate the validity, the accuracy, and the practical applicability of our results in complex networks scenarios and in smart grid applications.

Dorfler, Florian [Los Alamos National Laboratory; Chertkov, Michael [Los Alamos National Laboratory; Bullo, Francesco [Center for Control, Dynamical Systems and Computation, University of California at Santa Babara, Santa Barbara CA

2012-07-24T23:59:59.000Z

342

The Spatial and Temporal Dependence of Coronal Heating by Alfven Wave Turbulence  

E-Print Network [OSTI]

The solar atmosphere may be heated by Alfven waves that propagate up from the convection zone and dissipate their energy in the chromosphere and corona. To further test this theory, we consider wave heating in an active region observed on 2012 March 7. A potential field model of the region is constructed, and 22 field lines representing observed coronal loops are traced through the model. Using a three-dimensional (3D) reduced magneto-hydrodynamics (MHD) code, we simulate the dynamics of Alfven waves in and near the observed loops. The results for different loops are combined into a single formula describing the average heating rate Q as function of position within the observed active region. We suggest this expression may be approximately valid also for other active regions, and therefore may be used to construct 3D, time-dependent models of the coronal plasma. Such models are needed to understand the role of thermal non-equilibrium in the structuring and dynamics of the Sun's corona.

Asgari-Targhi, M; Cranmer, S R; DeLuca, E E

2013-01-01T23:59:59.000Z

343

Modeling Io's Sublimation-Driven Atmosphere: Gas Dynamics and Radiation Emission  

SciTech Connect (OSTI)

Io's sublimation-driven atmosphere is modeled using the direct simulation Monte Carlo method. These rarefied gas dynamics simulations improve upon earlier models by using a three-dimensional domain encompassing the entire planet computed in parallel. The effects of plasma impact heating, planetary rotation, and inhomogeneous surface frost are investigated. Circumplanetary flow is predicted to develop from the warm subsolar region toward the colder night-side. The non-equilibrium thermal structure of the atmosphere, including vibrational and rotational temperatures, is also presented. Io's rotation leads to an asymmetric surface temperature distribution which is found to strengthen circumplanetary flow near the dusk terminator. Plasma heating is found to significantly inflate the atmosphere on both day- and night-sides. The plasma energy flux also causes high temperatures at high altitudes but permits relatively cooler temperatures at low altitudes near the dense subsolar point due to plasma energy depletion. To validate the atmospheric model, a radiative transfer model was developed utilizing the backward Monte Carlo method. The model allows the calculation of the atmospheric radiation from emitting/absorbing and scattering gas using an arbitrary scattering law and an arbitrary surface reflectivity. The model calculates the spectra in the {nu}{sub 2} vibrational band of SO{sub 2} which are then compared to the observational data.

Walker, Andrew C.; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.; Moore, Chris H.; Stewart, Benedicte [University of Texas at Austin, Department of Aerospace Engineering, 210 East 24. Street W. R. Woolrich Laboratories 1 University Station, C0600 Austin, TX 78712 (United States); Gratiy, Sergey L.; Levin, Deborah A. [Pennsylvania State University, Department of Aerospace Engineering, 229 Hammond, University Park, PA 16802 (United States)

2008-12-31T23:59:59.000Z

344

Characteristics of atmospheric-pressure non-thermal N2 and N2/O2 gas mixture plasma jet  

Science Journals Connector (OSTI)

An atmospheric-pressure non-thermal plasma jet driven by high frequency alternating current and operating on N2 and N2/O2 gas mixture is investigated. The plasma jet can reach 55?mm in length at a gas flow rate of 2500?l/h. The gas temperature at a distance of 4?mm from the nozzle is close to room temperature. Optical emission spectroscopy is employed to investigate the important plasma parameters such as the excited species rotational temperature vibrational temperature and excitation temperature under different discharge conditions. The results show that the plasma source operates under non-equilibrium conditions. The absolute irradiance intensity of the vibrational band N2(C-B) in the active region is measured. Taking into account the irradiance intensity of N2(C-B 0-0) and N2(B-X 0-0) as well as measured current the electron density which is determined by considering direct and step-wise electron impact excitation of nitrogen emission reaches a maximum value of 5.6?×?1020/m3.

Dezhi Xiao; Cheng Cheng; Jie Shen; Yan Lan; Hongbing Xie; Xingsheng Shu; Jiangang Li; Paul K. Chu

2014-01-01T23:59:59.000Z

345

Hollow cathode cold atmospheric plasma source with monoatomic and molecular gases  

Science Journals Connector (OSTI)

Performance of the radio frequency (r.f.) hollow cathode at atmospheric pressure was tested for neon, argon, nitrogen and air. A non-equilibrium (cold) atmospheric plasma was generated in the gas flowing through the cathode. The electrode system was installed in a chamber open to ambient atmosphere. Two r.f. frequencies 13.56 and 27.12 \\{MHz\\} were compared. Similarly to the low pressure hollow cathodes the higher frequency was found to be more suitable for all tested gases, due to a lower minimum r.f. voltage and related power for ignition and sustaining a stable plasma. The fused hollow cathode (FHC) source produces a stable and uniform plasma over large area in monoatomic gases, suitable for surface treatment of temperature sensitive materials, for cleaning and surface activation applications. However, a substantial difference was found in discharge performance when using a molecular gas. An optimization of the impedance matching network enabled generation of a stable cold plasma at r.f. powers below 50 W in both air and nitrogen. Possibilities of a stable uniform air (or nitrogen) plasma generation over large areas by the FHC sources are discussed, too.

H Baránková; L Bárdoš

2003-01-01T23:59:59.000Z

346

The role of radiative reabsorption on the electron energy distribution functions in H{sub 2}/He plasma expansion through a tapered nozzle  

SciTech Connect (OSTI)

A collisional-radiative model for the H{sub 2}/He plasma, coupled to a Boltzmann solver for the free electron kinetics is used to investigate the non-equilibrium conditions created in the expansion of an high-temperature plasma flow through a converging-diverging nozzle, starting from the steady state composition at T{sub 0}=10?000?K and p{sub 0}=1?atm in the reservoir. It is shown that the plasma optical thickness plays a major role on the evolution of macroscopic quantities and internal distributions along the nozzle axis. Structured electron energy distribution functions, characterized by long plateaux and humps, are created due to superelastic collisions of cold electrons and electronically excited atomic hydrogen. The magnitudes of the plateaux are orders of magnitude higher in an optically thick plasma compared with a thin plasma, while the electron-electron collisions play a role in smoothing the peaks created by superelastic collisions between cold electrons and H(n>2)

D'Ammando, Giuliano, E-mail: g.dammando@chimica.uniba.it; Capitelli, Mario, E-mail: mario.capitelli@ba.imip.cnr.it [Dipartimento di Chimica, Universitá di Bari, Via Orabona 4, 70125 Bari (Italy); CNR-IMIP, Via Amendola 122/D, 70126 Bari (Italy); Esposito, Fabrizio, E-mail: fabrizio.esposito@ba.imip.cnr.it; Laricchiuta, Annarita, E-mail: annarita.laricchiuta@ba.imip.cnr.it; Pietanza, Lucia D., E-mail: daniela.pietanza@ba.imip.cnr.it; Colonna, Gianpiero, E-mail: gianpiero.colonna@ba.imip.cnr.it [CNR-IMIP, Via Amendola 122/D, 70126 Bari (Italy)

2014-09-15T23:59:59.000Z

347

High-resolution numerical simulation and analysis of Mach reflection structures in detonation waves in low-pressure H2 - O2 - Ar mixtures: a summary of results obtained with the adaptive mesh refinement framework AMROC  

SciTech Connect (OSTI)

Numerical simulation can be key to the understanding of the multi-dimensional nature of transient detonation waves. However, the accurate approximation of realistic detonations is demanding as a wide range of scales needs to be resolved. This paper describes a successful solution strategy that utilizes logically rectangular dynamically adaptive meshes. The hydrodynamic transport scheme and the treatment of the non-equilibrium reaction terms are sketched. A ghost fluid approach is integrated into the method to allow for embedded geometrically complex boundaries. Large-scale parallel simulations of unstable detonation structures of Chapman-Jouguet detonations in low-pressure hydrogen-oxygen-argon mixtures demonstrate the efficiency of the described techniques in practice. In particular, computations of regular cellular structures in two and three space dimensions and their development under transient conditions, i.e. under diffraction and for propagation through bends are presented. Some of the observed patterns are classified by shock polar analysis and a diagram of the transition boundaries between possible Mach reflection structures is constructed.

Deiterding, Ralf [ORNL

2011-01-01T23:59:59.000Z

348

Extension of the quantum-kinetic model to lunar and Mars return physics  

SciTech Connect (OSTI)

The ability to compute rarefied, ionized hypersonic flows is becoming more important as missions such as Earth reentry, landing high-mass payloads on Mars, and the exploration of the outer planets and their satellites are being considered. A recently introduced molecular-level chemistry model, the quantum-kinetic, or Q-K, model that predicts reaction rates for gases in thermal equilibrium and non-equilibrium using only kinetic theory and fundamental molecular properties, is extended in the current work to include electronic energy level transitions and reactions involving charged particles. Like the Q-K procedures for neutral species chemical reactions, these new models are phenomenological procedures that aim to reproduce the reaction/transition rates but do not necessarily capture the exact physics. These engineering models are necessarily efficient due to the requirement to compute billions of simulated collisions in direct simulation Monte Carlo (DSMC) simulations. The new models are shown to generally agree within the spread of reported transition and reaction rates from the literature for near equilibrium conditions.

Liechty, D. S. [Aerothermodynamics Branch, NASA Langley Research Center, Hampton, Virginia 23681 (United States)] [Aerothermodynamics Branch, NASA Langley Research Center, Hampton, Virginia 23681 (United States); Lewis, M. J. [Department of Aerospace Engineering, University of Maryland, College Park, Maryland 20742 (United States)] [Department of Aerospace Engineering, University of Maryland, College Park, Maryland 20742 (United States)

2014-02-15T23:59:59.000Z

349

Performance analysis of boron nitride embedded armchair graphene nanoribbon metal–oxide–semiconductor field effect transistor with Stone Wales defects  

SciTech Connect (OSTI)

We study the performance of a hybrid Graphene-Boron Nitride armchair nanoribbon (a-GNR-BN) n-MOSFET at its ballistic transport limit. We consider three geometric configurations 3p, 3p + 1, and 3p + 2 of a-GNR-BN with BN atoms embedded on either side (2, 4, and 6 BN) on the GNR. Material properties like band gap, effective mass, and density of states of these H-passivated structures are evaluated using the Density Functional Theory. Using these material parameters, self-consistent Poisson-Schrodinger simulations are carried out under the Non Equilibrium Green's Function formalism to calculate the ballistic n-MOSFET device characteristics. For a hybrid nanoribbon of width ?5?nm, the simulated ON current is found to be in the range of 265??A–280??A with an ON/OFF ratio 7.1 × 10{sup 6}–7.4 × 10{sup 6} for a V{sub DD}?=?0.68?V corresponding to 10?nm technology node. We further study the impact of randomly distributed Stone Wales (SW) defects in these hybrid structures and only 2.5% degradation of ON current is observed for SW defect density of 3.18%.

Chanana, Anuja; Sengupta, Amretashis; Mahapatra, Santanu [Nano Scale Device Research Laboratory, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 560 012 (India)

2014-01-21T23:59:59.000Z

350

Two-phase transition of Li-intercalation compounds in Li-ion batteries  

Science Journals Connector (OSTI)

Among all electrode materials, olivine LiFePO4 and spinel Li4Ti5O12 are well-known for their two-phase structure, characterized by a flat voltage plateau. The phase transition in olivine LiFePO4 may be modeled in single particle and many-particle systems at room temperature, based on the thermodynamic phase diagram which is easily affected by coherency strain and the size effect. Some metastable and transient phases in the phase diagram can also be detected during non-equilibrium electrochemical processes. In comparison to olivine LiFePO4, spinel Li4Ti5O12 possesses a ‘zero strain’ property and performs Li-site switching during the phase transition, which lead to a different phase structure. Here, the phase transitions of olivine LiFePO4 and spinel Li4Ti5O12 are systematically reviewed, and the concepts discussed may be extended to other two-phase Li-intercalation compounds in Li-ion batteries.

De Li; Haoshen Zhou

2014-01-01T23:59:59.000Z

351

Equilibration processes in the Warm-Hot Intergalactic Medium  

E-Print Network [OSTI]

The Warm-Hot Intergalactic Medium (WHIM) is thought to contribute about 40-50 % to the baryonic budget at the present evolution stage of the universe. The observed large scale structure is likely to be due to gravitational growth of density fluctuations in the post-inflation era. The evolving cosmic web is governed by non-linear gravitational growth of the initially weak density fluctuations in the dark energy dominated cosmology. Non-linear structure formation, accretion and merging processes, star forming and AGN activity produce gas shocks in the WHIM. Shock waves are converting a fraction of the gravitation power to thermal and non-thermal emission of baryonic/leptonic matter. They provide the most likely way to power the luminous matter in the WHIM. The plasma shocks in the WHIM are expected to be collisionless. Collisionless shocks produce a highly non-equilibrium state with anisotropic temperatures and a large differences in ion and electron temperatures. We discuss the ion and electron heating by the collisionless shocks and then review the plasma processes responsible for the Coulomb equilibration and collisional ionisation equilibrium of oxygen ions in the WHIM. MHD-turbulence produced by the strong collisionless shocks could provide a sizeable non-thermal contribution to the observed Doppler parameter of the UV line spectra of the WHIM.

A. M. Bykov; F. B. S. Paerels; V. Petrosian

2008-01-07T23:59:59.000Z

352

Gamma-ray burst spectra and spectral correlations from sub-photospheric Comptonization  

E-Print Network [OSTI]

One of the most important unresolved issues in gamma-ray burst physics is the origin of the prompt gamma-ray spectrum. Its general non-thermal character and the softness in the X-ray band remain unexplained. We tackle these issues by performing Monte Carlo simulations of radiation-matter interactions in a scattering dominated photon-lepton plasma. The plasma -- initially in equilibrium -- is driven to non-equilibrium conditions by a sudden energy injection in the lepton population, mimicking the effect of a shock wave or the dissipation of magnetic energy. Equilibrium restoration occurs due to energy exchange between the photons and leptons. While the initial and final equilibrium spectra are thermal, the transitional photon spectra are characterized by non-thermal features such as power-law tails, high energy bumps, and multiple components. Such non-thermal features are observed at infinity if the dissipation occurs at small to moderate optical depths, and the spectrum is released before thermalization is co...

Chhotray, Atul

2015-01-01T23:59:59.000Z

353

Gravitationally Induced Particle Production: Thermodynamics and Kinetic Theory  

E-Print Network [OSTI]

A relativistic kinetic description for the irreversible thermodynamic process of gravitationally induced particle production is proposed in the context of an expanding Friedmann-Robertson-Walker (FRW) geometry. We show that the covariant thermodynamic treatment referred to as "adiabatic" particle production provoked by the cosmic time-varying gravitational field has a consistent kinetic counterpart. The variation of the distribution function is associated to a non-collisional kinetic term of quantum-gravitational origin which is proportional to the ratio $\\Gamma/H$, where $\\Gamma$ is the gravitational particle production rate and H is the Hubble parameter. For $\\Gamma gravitation. The resulting non-equilibrium distribution function has the same functional form of equilibrium with the evolution laws corrected by the particle production process. The macroscopic temperature evolution law is also kinetically derived for massive and massless particles. The present approach points to the possibility of an exact (semi-classical) quantum-gravitational kinetic treatment by incorporating back-reaction effects in the cosmic background.

J. A. S. Lima; I. P. Baranov

2014-11-24T23:59:59.000Z

354

Nonequilibrium Thermoelectrics: Low-Cost, High-Performance Materials for Cooling and Power Generation  

SciTech Connect (OSTI)

Thermoelectric materials can be made into coolers (TECs) that use electricity to develop a temperature difference, cooling something, or generators (TEGs) that convert heat directly to electricity. One application of TEGs is to place them in a waste heat stream to recuperate some of the power being lost and putting it to use more profitably. To be effective thermoelectrics, however, materials must have both high electrical conductivity and low thermal conductivity, a combination rarely found in nature. Materials selection and processing has led to the development of several systems with a figure of merit, ZT, of nearly unity. By using non-equilibrium techniques, we have fabricated higher efficiency thermoelectric materials. The process involves creating an amorphous material through melt spinning and then sintering it with either spark plasma or a hot press for as little as two minutes. This results in a 100% dense material with an extremely fine grain structure. The grain boundaries appear to retard phonons resulting in a reduced thermal conductivity while the electrons move through the material relatively unchecked. The techniques used are low-cost and scaleable to support industrial manufacturing.

Li, Q.

2011-05-18T23:59:59.000Z

355

Cosmological production of H_2 before the formation of the first galaxies  

E-Print Network [OSTI]

Previous calculations of the pregalactic chemistry have found that a small amount of H_2, x[H_2]=n[H_2]/n[H] = 2.6e-6, is produced catalytically through the H^-, H_2^+, and HeH^+ mechanisms. We revisit this standard calculation taking into account the effects of the nonthermal radiation background produced by cosmic hydrogen recombination, which is particularly effective at destroying H^- via photodetachment. We also take into consideration the non-equilibrium level populations of H_2^+, which occur since transitions among the rotational-vibrational levels are slow compared to photodissociation. The new calculation predicts a final H_2 abundance of x[H_2] = 6e-7 for the standard cosmology. This production is due almost entirely to the H^- mechanism, with ~1 per cent coming from HeH^+ and ~0.004 per cent from H_2^+. We evaluate the heating of the diffuse pregalactic gas from the chemical reactions that produce H_2 and from rotational transitions in H_2, and find them to be negligible.

Christopher M. Hirata; Nikhil Padmanabhan

2006-06-19T23:59:59.000Z

356

Ballistic vs. diffusive heat transfer across nanoscopic films of layered crystals  

SciTech Connect (OSTI)

We use non-equilibrium molecular dynamics to study the heat transfer mechanism across sandwich interfacial structures of Si/n-atomic-layers/Si, with 1???n???20 and atomic layers composed of WSe{sub 2} and/or graphene. In the case of WSe{sub 2} sheets, we observe that the thermal resistance of the sandwich structure is increasing almost linearly with the number of WSe{sub 2} sheets, n, indicating a diffusive phonon transport mechanism. By contrast in the case of n graphene layers, the interfacial thermal resistance is more or less independent on the number of layers for 1???n???10, and is associated with ballistic phonon transport mechanism. We attribute the diffusive heat transfer mechanism across WSe{sub 2} sheets to abundant low frequency and low group velocity optical modes that carry most of the heat across the interface. By contrast, in graphene, acoustic modes dominate the thermal transport across the interface and render a ballistic heat flow mechanism.

Shen, Meng; Keblinski, Pawel, E-mail: keblip@rpi.edu [Department of Materials Science and Engineering, and Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2014-04-14T23:59:59.000Z

357

Molecular dynamics simulation of shock induced ejection on fused silica surface  

SciTech Connect (OSTI)

Shock response and surface ejection behaviors of fused silica are studied by using non-equilibrium molecular dynamics combining with the Tersoff potential. First, bulk structure and Hugoniot curves of fused silica are calculated and compared with experimental results. Then, the dynamical process of surface ejection behavior is simulated under different loading velocities ranging from 3.5 to 5.0?km?s, corresponding to shock wave velocities from 7.1 to 8.8?km?s. The local atomistic shear strain parameter is used to describe the local plastic deformation under conditions of shock compression or releasing. Our result shows that the shear strain is localized in the bottom area of groove under the shock compression. Surface ejection is observed when the loading velocity exceeds 4.0?km?s. Meanwhile, the temperature of the micro-jet is ?5574.7?K, which is close to experiment measurement. Several kinds of structural defects including non-bridging oxygen are found in the bulk area of the sample after ejection.

Su, Rui [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Xiang, Meizhen; Jiang, Shengli [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Chen, Jun, E-mail: jun-chen@iapcm.ac.cn [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Center for Applied Physics and Technology, Peking University, Beijing 100087 (China); Wei, Han [Research Center of Laser Fusion, Mianyang 621900 (China)

2014-05-21T23:59:59.000Z

358

Negative differential resistance devices by using N-doped graphene nanoribbons  

SciTech Connect (OSTI)

Recently, extensive efforts have been devoted to the investigations of negative differential resistance (NDR) behavior in graphene. Here, by performing fully self-consistent density functional theory calculations combined with non-equilibrium Green's function technique, we investigate the transport properties of three molecules from conjugated molecule, one-dimension alkane chain, and single molecule magnet, which are sandwiched between two N-doped zigzag and armchair graphene nanoribbons (GNRs). We observe robust NDR effect in all examined molecular junctions including benzene, alkane, and planar four-coordinated Fe complex. Through the analyses of the calculated electronic structures and the bias-dependent transmission coefficients, we find that the narrow density of states of N-doped GNRs and the bias-dependent effective coupling between the discrete frontier molecular orbitals and the subbands of N-doped GNRs are responsible for the observed NDR phenomenon. These theoretical findings imply that N-doped GNRs hold great potential for building NDR devices based on various molecules.

Huang, Jing, E-mail: jhuang@ustc.edu.cn, E-mail: liqun@ustc.edu.cn [School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, Anhui 230601 (China) [School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, Anhui 230601 (China); Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang, Weiyi; Li, Qunxiang, E-mail: jhuang@ustc.edu.cn, E-mail: liqun@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yang, Jinlong [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-04-28T23:59:59.000Z

359

Thermodynamic and transport properties of two-temperature SF{sub 6} plasmas  

SciTech Connect (OSTI)

This paper deals with thermodynamic and transport properties of SF{sub 6} plasmas in a two-temperature model for both thermal equilibrium and non-equilibrium conditions. The species composition and thermodynamic properties are numerically determined using the two-temperature Saha equation and Guldberg-Waage equation according to deviation of van de Sanden et al. Transport properties including diffusion coefficient, viscosity, thermal conductivity, and electrical conductivity are calculated with most recent collision interaction potentials by adopting Devoto's electron and heavy particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) in the frame of Chapman-Enskog method. The results are computed for various values of pressures from 0.1 atm to 10 atm and ratios of the electron temperature to the heavy particle temperature from 1 to 20 with electron temperature range from 300 to 40 000 K. In the local thermodynamic equilibrium regime, results are compared with available results of previously published studies.

Wang Weizong [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an Shaanxi 710049 (China); Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool L69 3GJ (United Kingdom); Rong Mingzhe; Wu Yi [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an Shaanxi 710049 (China); Spencer, Joseph W.; Yan, Joseph D.; Mei, DanHua [Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool L69 3GJ (United Kingdom)

2012-08-15T23:59:59.000Z

360

From dissipative dynamics to studies of heat transfer at the nanoscale  

E-Print Network [OSTI]

We study in a unified manner the dissipative dynamics and the transfer of heat in the two-bath spin-boson model. We use the Bloch-Redfield (BR) formalism, valid in the very weak system-bath coupling limit, the noninteracting-blip approximation (NIBA), applicable in the non-adiabatic limit, and iterative, numerically-exact path integral tools. These methodologies were originally developed for the description of the dissipative dynamics of a quantum system, and here they are applied to explore the problem of quantum energy transport in a non-equilibrium setting. Specifically, we study the weak-to-intermediate system-bath coupling regime at high temperatures $k_BT/\\hbar>\\epsilon$, with $\\epsilon$ as the characteristic frequency of the two-state system. The BR formalism and NIBA can lead to close results for the dynamics of the reduced density matrix (RDM) in a certain range of parameters. However, relatively small deviations in the RDM dynamics propagate into significant qualitative discrepancies in the transpor...

Boudjada, Nazim

2014-01-01T23:59:59.000Z

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361

Heirarchical Self Assembly: Self Organized nano-structures in a nematically ordered matrix of self assembled polymeric chains  

E-Print Network [OSTI]

We report many different nano-structures which are formed when model nano-particles of different sizes (diameter {\\sigma} n ) are allowed to aggregate in a background matrix of semi-flexible self assembled polymeric worm like micellar chains. The different nano-structures are formed by the dynamical arrest of phase-separating mixtures of micellar monomers and nano-particles. The different mor- phologies obtained are the result of an interplay of the available free volume, the elastic energy of deformation of polymers, the density (chemical potential) of the nano-particles in the polymer ma- trix and, of course, the ratio of the size of self assembling nano-particles and self avoidance diameter of polymeric chains. We have used a hybrid semi-grand canonical Monte Carlo simulation scheme to obtain the (non-equilibrium) phase diagram of the self-assembled nano-structures. We observe rod-like structures of nano-particles which get self assembled in the gaps between the nematically ordered chains as well as percolating gel-like network of conjoined nanotubes. We also find a totally unexpected interlocked crystalline phase of nano-particles and monomers, in which each crytal plane of nanoparticles is separated by planes of perfectly organized polymer chains. We identified the con- dition which leads to such interlocked crystal structure. We suggest experimental possibilities of how the results presented in this paper could be used to obtain different nano-structures in the lab.

Shaikh Mubeena; Apratim Chatterji

2014-12-04T23:59:59.000Z

362

Models of crustal heating in accreting neutron stars  

E-Print Network [OSTI]

Heating associated with non-equilibrium nuclear reactions in accreting neutron-star crusts is reconsidered, taking into account suppression of neutrino losses demonstrated recently by Gupta et al. Two initial compositions of the nuclear burning ashes, A=56 and A=106, are considered. Dependence of the integrated crustal heating on uncertainties plaguing pycnonuclear reaction models is studied. One-component plasma approximation is used, with compressible liquid-drop model of Mackie and Baym to describe nuclei. Evolution of a crust shell is followed from 10^8 g/cm^3 to 10^(13.6) g/cm^3 The integrated heating in the outer crust agrees nicely with results of self-considtent multicomponent plasma simulations of Gupta et al.; their results fall between our curves obtained for A=56 and A=106. Total crustal heat per one accreted nucleon ranges between 1.5 MeV to 1.9 MeV for A=106 and A=56, respectively. The value of total crustal heat per nucleon depends weakly on the presence of pycnonuclear reactions at densities 10^(12)-10^(13) g/cm^3. Remarkable insensitivity of the total crustal heat on the details of the distribution of nuclear processes in accreted crust is explained.

P. Haensel; J. L. Zdunik

2007-08-29T23:59:59.000Z

363

Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective  

SciTech Connect (OSTI)

Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."

Anders, Andre

2007-02-28T23:59:59.000Z

364

Universal patterns of inequality  

Science Journals Connector (OSTI)

Probability distributions of money, income and energy consumption per capita are studied for ensembles of economic agents. The principle of entropy maximization for partitioning of a limited resource gives exponential distributions for the investigated variables. A non-equilibrium difference of money temperatures between different systems generates net fluxes of money and population. To describe income distribution, a stochastic process with additive and multiplicative components is introduced. The resultant distribution interpolates between exponential at the low end and power law at the high end, in agreement with the empirical data for the USA. We show that the increase in income inequality in the USA originates primarily from the increase in the income fraction going to the upper tail, which now exceeds 20% of the total income. Analyzing the data from the World Resources Institute, we find that the distribution of energy consumption per capita around the world can be approximately described by the exponential function. Comparing the data for 1990, 2000 and 2005, we discuss the effect of globalization on the inequality of energy consumption.

Anand Banerjee; Victor M Yakovenko

2010-01-01T23:59:59.000Z

365

A thermodynamic analysis of alternative approaches to chemical looping combustion  

SciTech Connect (OSTI)

In this article, we review and clarify some of the points made by previous authors regarding chemical looping combustion (CLC). While much of the recent interest in chemical looping combustion has been associated with carbon sequestration, our primary interest here is its potential to increase the thermodynamic efficiency of converting fuel chemical energy into useful work. We expand on several points about the details of CLC that we feel have not previously been sufficiently explored, and suggest alternative (and possibly more practical) approaches that exploit some of the same thermodynamic concepts. We illustrate our key points with {First} and {Second} Law analyses of ideal conceptual processes, which in addition to {CLC} also include isothermal, non-equilibrium, preheated combustion and combustion with thermochemical recuperation. Our results suggest that a significant portion of the potential efficiency benefit of CLC might be achieved without the need to handle and transport large quantities of solid oxygen storage material. Exploitation of this fact may lead to higher efficiency approaches for power generation from hydrocarbon fuels combustion.

Chakravarthy, Veerathu K [ORNL; Daw, C Stuart [ORNL; Pihl, Josh A [ORNL

2011-01-01T23:59:59.000Z

366

Direct Observations of Plasma Upflows and Condensation in a Catastrophically Cooling Solar Transition Region Looop  

E-Print Network [OSTI]

Minimal observational evidence exists for fast transition region (TR) upflows in the presence of cool loops. Observations of such occurrences challenge notions of standard solar atmospheric heating models, as well as their description of bright TR emission. Using the {\\it EUV Imaging Spectrometer} (EIS) onboard {\\it Hinode}, we observe fast upflows ($v_\\lambda$\\,$\\le$\\,$-$10 km s$^{-1}$) over multiple TR temperatures (5.8\\,$\\le$\\,$\\log T$\\,$\\le$ 6.0) at the footpoint sites of a cool loop ($\\log T$\\,$\\le$\\,6.0). Prior to cool loop energizing, asymmetric flows of $+$\\,5 km s$^{-1}$ and $-$\\,60 km s$^{-1}$ are observed at footpoint sites. These flows speeds and patterns occur simultaneously with both magnetic flux cancellation (at site of upflows only) derived from the {\\it Solar Dynamics Observatory}'s (SDOs) { \\it Helioseismic Magnetic Imager}'s (HMI) line-of-sight magnetogram images, and a 30\\% mass in-flux at coronal heights. The incurred non-equilibrium structure of the cool loop leads to a catastrophic coo...

Orange, N B; Oluseyi, H M; Hesterly, K; Patel, M; Champey, P R

2015-01-01T23:59:59.000Z

367

A New Ontological View of the Quantum Measurement Problem  

E-Print Network [OSTI]

A new ontological view of the quantum measurement processes is given, which has bearings on many broader issues in the foundations of quantum mechanics as well. In this scenario a quantum measurement is a non-equilibrium phase transition in a ``resonant cavity'' formed by the entire physical universe including all of its material and energy content. A quantum measurement involves the energy and matter exchange among not only the system being measured and the measuring apparatus but also the global environment of the universe resonant cavity, which together constrain the nature of the phase transition. Strict realism, including strict energy and angular momentum conservation, is recovered in this view of the quantum measurement process beyond the limit set by the uncertainty relations, which are themselves derived from the exact commutation relations for quantum conjugate variables. Both the amplitude and the phase of the quantum mechanical wavefunction acquire substantial meanings in the new ontology, and the probabilistic element is removed from the foundations of quantum mechanics, its apparent presence in the quantum measurement being solely a result of the sensitive dependence on initial/boundary conditions of the phase transitions of a many degree-of-freedom system which is effectively the whole universe. Vacuum fluctuations are viewed as the ``left over'' fluctuations after forming the whole numbers of nonequilibrium resonant modes in the universe cavity. This new view on the quantum processes helps to clarify many puzzles in the foundations of quantum mechanics.

Xiaolei Zhang

2005-06-13T23:59:59.000Z

368

Light Activated Self-Propelled Colloids  

E-Print Network [OSTI]

Light-activated self-propelled colloids are synthesized and their active motion is studied using optical microscopy. We propose a versatile route using different photoactive materials, and demonstrate a multiwavelength activation and propulsion. Thanks to the photoelectrochemical properties of two semiconductor materials (\\alpha Fe2 O3 and TiO2 ), a light with an energy higher than the bandgap triggers the reaction of decomposition of hydrogen peroxide and produces a chemical cloud around the particle. It induces a phoretic attraction with neighbouring colloids as well as an osmotic self- propulsion of the particle on the substrate. We use these mechanisms to form colloidal cargos as well as self-propelled particles where the light-activated component is embedded into a dielectric sphere. The particles are self-propelled along a direction otherwise randomized by thermal fluctuations, and exhibit a persistent random walk. For sufficient surface density, the particles spontaneously form "living crystals" which are mobile, break apart and reform. Steering the particle with an external magnetic field, we show that the formation of the dense phase results from the collisions heads-on of the particles. This effect is intrinsically non-equilibrium and a novel principle of organization for systems without detailed balance. Engineering families of particles self-propelled by different wavelength demonstrate a good understanding of both the physics and the chemistry behind the system and points to a general route for designing new families of self-propelled particles.

J. Palacci; S. Sacanna; S. -H. Kim; G. -R. Yi; D. J. Pine; P. M. Chaikin

2014-10-27T23:59:59.000Z

369

In Situ Heating of the 2007 May 19 CME Ejecta Detected by STEREO/PLASTIC and ACE  

E-Print Network [OSTI]

In situ measurements of ion charge states can provide unique insight into the heating and evolution of coronal mass ejections when tested against realistic non-equilibrium ionization modeling. In this work we investigate the representation of the CME magnetic field as an expanding spheromak configuration, where the plasma heating is prescribed by the choice of anomalous resistivity and the spheromak dynamics. We chose as a test case, the 19 May 2007 CME observed by STEREO and ACE. The spheromak is an appealing physical model, because the location and degree of heating is fixed by the choice of anomalous resistivity and the spheromak expansion rate which we constrain with observations. This model can provide the heating required between 1.1$R_{\\sun}$ and earth orbit to produce charge states observed in the CME flux rope. However this source of heating in the spheromak alone has difficulty accounting for the rapid heating to Fe$^{8 - 11+}$ at lower heights, as observed in STEREO EUVI due to the rapid radiative ...

Rakowski, Cara E; Lyutikov, Maxim

2011-01-01T23:59:59.000Z

370

Transport, Aharonov-Bohm, and Topological Effects in Graphene Molecular Junctions and Graphene Nanorings  

E-Print Network [OSTI]

The unique ultra-relativistic, massless, nature of electron states in two-dimensional extended graphene sheets, brought about by the honeycomb lattice arrangement of carbon atoms in two-dimensions, provides ingress to explorations of fundamental physical phenomena in graphene nanostructures. Here we explore the emergence of new behavior of electrons in atomically precise segmented graphene nanoribbons (GNRs) and graphene rings with the use of tight-binding calculations, non-equilibrium Green's function transport theory, and a newly developed Dirac continuum model that absorbs the valence-to-conductance energy gaps as position-dependent masses, including topological-in-origin mass-barriers at the contacts between segments. Through transport investigations in variable-width segmented GNRs with armchair, zigzag, and mixed edge terminations we uncover development of new Fabry-Perot-like interference patterns in segmented GNRs, a crossover from the ultra-relativistic massless regime, characteristic of extended graphene systems, to a massive relativistic behavior in narrow armchair GNRs, and the emergence of nonrelativistic behavior in zigzag-terminated GNRs. Evaluation of the electronic states in a polygonal graphene nanoring under the influence of an applied magnetic field in the Aharonov-Bohm regime, and their analysis with the use of a relativistic quantum-field theoretical model, unveils development of a topological-in-origin zero-energy soliton state and charge fractionization. These results provide a unifying framework for analysis of electronic states, coherent transport phenomena, and the interpretation of forthcoming experiments in segmented graphene nanoribbons and polygonal rings.

Constantine Yannouleas; Igor Romanovsky; Uzi Landman

2015-02-16T23:59:59.000Z

371

Is electrospray emission really due to columbic forces?  

SciTech Connect (OSTI)

Electrospray ionization (ESI) is a widely adopted soft ionization method for mass spectroscopy (MS). In spite of the undeniable success of the technique, its mechanisms are difficult to be analytically modelled because the process is characterized by non-equilibrium conditions. The common belief is that the formation of gas-phase ions takes place at the apex of the Taylor cone via electrophoretic charging. The charge balance implies that a conversion of electrons to ions should occur at the metal-liquid interface of the injector needle. We have detected that the above description is based on unproved assumptions which are not consistent with the correct evaluation of the problem. The comparison between experiments performed under the usual geometry and observations obtained under symmetric field configurations suggests that the emitted droplets cannot be significantly charged or, at least, that any possible ionization mechanism is so poorly efficient to ensure that columbic forces cannot play a major role in jet formation, even in cases where the liquid consists of a solution of ionic species. Further work is required to clearly understand how ionization occurs in ESI-MS.

Aliotta, Francesco, E-mail: aliotta@ipcf.cnr.it; Ponterio, Rosina C.; Salvato, Gabriele; Vasi, Cirino [CNR-Istituto per i Processi Chimico-Fisici, Viale F. Stagno d’Alcontres 37, I-98158 Messina (Italy); Calandra, Pietro [CNR-Istituto per lo Studio dei Materiali Nanostrutturati, via dei Taurini 19, I-00185 Roma (Italy); Pochylski, Mikolaj [Adam Mickiewicz University, Faculty of Physics, Umultowska 85, PL-62614 Poznan (Poland)

2014-09-15T23:59:59.000Z

372

Preliminary Measurements From A New Flat Plate Facility For Aerodynamic Research  

SciTech Connect (OSTI)

This paper details the design and preliminary measurements used in the characterisation of a new flat plate research facility. The facility is designed specifically to aid in the understanding of entropy generation throughout the boundary layer with special attention given to non-equilibrium flows. Hot-wire measurements were obtained downstream of two turbulence generating grids. The turbulence intensity, integral and dissipation length scale ranges measured are 1.6%-7%, 5mm-17mm and 0.7mm-7mm, respectively. These values compared well to existing correlations. The flow downstream of both grids was found to be homogenous and isotropic. Flow visualisation is employed to determine aerodynamic parameters such as flow 2-dimensionality and the effect of the flap angle on preventing separation at the leading edge. The flow was found to be 2-dimensional over all measurement planes. The non-dimensional pressure distribution of a modern turbine blade suction surface is simulated on the flat plate through the use of a variable upper wall. The Reynolds number range based on wetted plate length and inlet velocity is 70,000-4,000,000.

D. M. McEligot; D. W. Nigg; E. J. Walsh; D. Hernon; M.R.D. Davies

2005-03-01T23:59:59.000Z

373

Cell development obeys maximum Fisher information  

E-Print Network [OSTI]

Eukaryotic cell development has been optimized by natural selection to obey maximal intracellular flux of messenger proteins. This, in turn, implies maximum Fisher information on angular position about a target nuclear pore complex (NPR). The cell is simply modeled as spherical, with cell membrane (CM) diameter 10 micron and concentric nuclear membrane (NM) diameter 6 micron. The NM contains about 3000 nuclear pore complexes (NPCs). Development requires messenger ligands to travel from the CM-NPC-DNA target binding sites. Ligands acquire negative charge by phosphorylation, passing through the cytoplasm over Newtonian trajectories toward positively charged NPCs (utilizing positive nuclear localization sequences). The CM-NPC channel obeys maximized mean protein flux F and Fisher information I at the NPC, with first-order delta I = 0 and approximate 2nd-order delta I = 0 stability to environmental perturbations. Many of its predictions are confirmed, including the dominance of protein pathways of from 1-4 proteins, a 4nm size for the EGFR protein and the approximate flux value F =10^16 proteins/m2-s. After entering the nucleus, each protein ultimately delivers its ligand information to a DNA target site with maximum probability, i.e. maximum Kullback-Liebler entropy HKL. In a smoothness limit HKL approaches IDNA/2, so that the total CM-NPC-DNA channel obeys maximum Fisher I. Thus maximum information approaches non-equilibrium, one condition for life.

B. R. Frieden; R. A. Gatenby

2014-04-29T23:59:59.000Z

374

Spatially Resolved X-ray Spectroscopy of Vela Shrapnel A  

E-Print Network [OSTI]

We present the detailed X-ray spectroscopy of Vela shrapnel A with the XMM-Newton satellite. Vela shrapnel A is one of several protrusions identified as bullets from Vela supernova explosion. The XMM-Newton image shows that shrapnel A consists of a bright knot and a faint trailing wake. We extracted spectra from various regions, finding a prominent Si Ly$_\\alpha$ emission line in all the spectra. All the spectra are well represented by the non-equilibrium ionization (NEI) model. The abundances are estimated to be O$\\sim$0.3, Ne$\\sim$0.9, Mg$\\sim$0.8, Si$\\sim$3, Fe$\\sim$0.8 times their solar values. The non-solar abundance ratio between O and Si indicates that shrapnel A originates from a deep layer of a progenitor star. We found that the relative abundances between heavy elements are almost uniform in shrapnel A, which suggests that the ejecta from supernova explosion are well mixed with swept-up interstellar medium.

S. Katsuda; H. Tsunemi

2006-03-17T23:59:59.000Z

375

Strangeness enhancement at the hadronic chemical freeze-out  

E-Print Network [OSTI]

The chemical freeze-out of hadrons created in the high energy nuclear collisions is studied within the realistic version of the hadron resonance gas model. The chemical non-equilibrium of strange particles is accounted via the usual $\\gamma_{s}$ factor which gives us an opportunity to perform a high quality fit with $\\chi^2/dof \\simeq 63.5/55 \\simeq 1.15$ of the hadronic multiplicity ratios measured from the low AGS to the highest RHIC energies. In contrast to previous findings, at low energies we observe the strangeness enhancement instead of a suppression. In addition, the performed $\\gamma_{s}$ fit allows us to achieve the highest quality of the Strangeness Horn description with $\\chi^2/dof=3.3/14$. For the first time the top point of the Strangeness Horn is perfectly reproduced, which makes our theoretical horn as sharp as an experimental one. However, the $\\gamma_{s}$ fit approach does not sizably improve the description of the multi-strange baryons and antibaryons. Therefore, an apparent deviation of multi-strange baryons and antibaryons from chemical equilibrium requires further explanation.

V. V. Sagun; D. R. Oliinychenko; K. A. Bugaev; J. Cleymans; A. I. Ivanytskyi; I. N. Mishustin; E. G. Nikonov

2014-03-25T23:59:59.000Z

376

Stochastic Mean Field Model of Heat Engine partitioned by Fluctuating Piston  

E-Print Network [OSTI]

We propose a stochastic mean field model of heat engine partitioned by a finite-mass piston. The time evolution equations for the density and the temperature of the enclosed gas are proposed, taking into account the stochastic equation of motion of the piston, and the energy conservation for the gas. Though the heat cycle consisting of finite-time heating and cooling processes is under strong non-equilibrium situations, i. e., the ratio of temperatures of two reservoirs is large, we analyze the efficiency and the power, and derive the semi-analytical expression for the efficiency. We find that the obtained efficiency at the maximum power operation is close to the Chambadal-Novikov-Curzon-Ahlborn (CNCA) efficiency, if the piston is sufficiently heavy and elastic for collisions with particles, even when the system is far from equilibrium. However, the extra heat due to the finiteness of the piston-mass or its inelasticity lowers the efficiency from the CNCA efficiency. The results of our stochastic mean field model are consistent with those for our event driven molecular dynamics simulation.

Tomohiko G. Sano; Hisao Hayakawa

2014-12-15T23:59:59.000Z

377

Controlled Population of Floquet-Bloch States via Coupling to Bose and Fermi Baths  

E-Print Network [OSTI]

External driving is emerging as a promising tool for exploring new phases in quantum systems. The intrinsically non-equilibrium states that result, however, are challenging to describe and control. We study the steady states of a periodically driven one-dimensional electronic system, including the effects of radiative recombination, electron-phonon interactions, and the coupling to an external fermionic reservoir. Using a kinetic equation for the populations of the Floquet eigenstates, we show that the steady-state distribution can be controlled using the momentum and energy relaxation pathways provided by the coupling to phonon and Fermi reservoirs. In order to utilize the latter, we propose to couple the system and reservoir via an energy filter which suppresses photon-assisted tunneling. Importantly, coupling to these reservoirs yields a steady state resembling a band insulator in the Floquet basis. The system exhibits incompressible behavior, while hosting a small density of excitations. We discuss transport signatures, and describe the regimes where insulating behavior is obtained. Our results give promise for realizing Floquet topological insulators.

Karthik I. Seetharam; Charles-Edouard Bardyn; Netanel H. Lindner; Mark S. Rudner; Gil Refael

2015-02-09T23:59:59.000Z

378

On the use of the double floating probe method to infer the difference between the electron and the heavy particles temperatures in an atmospheric pressure, vortex-stabilized nitrogen plasma jet  

SciTech Connect (OSTI)

Sweeping double probe measurements in an atmospheric pressure direct current vortex-stabilized plasma jet are reported (plasma conditions: 100 A discharge current, N{sub 2} gas flow rate of 25 Nl/min, thoriated tungsten rod-type cathode, copper anode with 5 mm inner diameter). The interpretation of the double probe characteristic was based on a generalization of the standard double floating probe formulae for non-uniform plasmas coupled to a non-equilibrium plasma composition model. Perturbations caused by the current to the probe together with collisional and thermal processes inside the probe perturbed region were taken into account. Radial values of the average electron and heavy particle temperatures as well as the electron density were obtained. The calculation of the temperature values did not require any specific assumption about a temperature relationship between different particle species. An electron temperature of 10?900 ± 900 K, a heavy particle temperature of 9300 ± 900 K, and an electron density of about 3.5 × 10{sup 22} m{sup ?3} were found at the jet centre at 3.5 mm downstream from the torch exit. Large deviations from kinetic equilibrium were found toward the outer border of the plasma jet. These results showed good agreement with those previously reported by the authors by using a single probe technique. The calculations have shown that this method is particularly useful for studying spraying-type plasma torches operated at power levels of about 15 kW.

Prevosto, L., E-mail: prevosto@waycom.com.ar; Mancinelli, B. R. [Grupo de Descargas Eléctricas, Departamento Ingeniería Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, 2600 Venado Tuerto, Santa Fe (Argentina)] [Grupo de Descargas Eléctricas, Departamento Ingeniería Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, 2600 Venado Tuerto, Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ingeniería Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, 2600 Venado Tuerto, Santa Fe (Argentina) [Grupo de Descargas Eléctricas, Departamento Ingeniería Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, 2600 Venado Tuerto, Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina)

2014-05-15T23:59:59.000Z

379

A diffuse interface model with immiscibility preservation  

SciTech Connect (OSTI)

A new, simple, and computationally efficient interface capturing scheme based on a diffuse interface approach is presented for simulation of compressible multiphase flows. Multi-fluid interfaces are represented using field variables (interface functions) with associated transport equations that are augmented, with respect to an established formulation, to enforce a selected interface thickness. The resulting interface region can be set just thick enough to be resolved by the underlying mesh and numerical method, yet thin enough to provide an efficient model for dynamics of well-resolved scales. A key advance in the present method is that the interface regularization is asymptotically compatible with the thermodynamic mixture laws of the mixture model upon which it is constructed. It incorporates first-order pressure and velocity non-equilibrium effects while preserving interface conditions for equilibrium flows, even within the thin diffused mixture region. We first quantify the improved convergence of this formulation in some widely used one-dimensional configurations, then show that it enables fundamentally better simulations of bubble dynamics. Demonstrations include both a spherical-bubble collapse, which is shown to maintain excellent symmetry despite the Cartesian mesh, and a jetting bubble collapse adjacent a wall. Comparisons show that without the new formulation the jet is suppressed by numerical diffusion leading to qualitatively incorrect results.

Tiwari, Arpit, E-mail: atiwari2@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)] [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Freund, Jonathan B., E-mail: jbfreund@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Pantano, Carlos [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)] [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

2013-11-01T23:59:59.000Z

380

Microstructural Aspects of Irradiation Damage in A508 Gr 4N Forging Steel: Composition and Flux Effects  

SciTech Connect (OSTI)

Neutron irradiation can promote significant changes in the microstructure and associated mechanical properties of low alloy steels. In particular, irradiation can induce the formation of non-equilibrium phases and segregation, which may lead to a degradation in toughness. In this study, the microstructural changes caused by neutron irradiation have been characterized in A508 Grade (Gr) 4N-type steels ({approx}3.5% Ni) using a variety of state-of-the-art analytical techniques including 3D-Atom Probe Field-Ion Microscopy and Small Angle Neutron Scattering, along with post-irradiation annealing studies combining Positron Annihilation Lineshape Analysis and hardness measurements. Important differences between conventional and ''superclean'' A508 Gr 4N steel have been identified in this investigation. The data indicate that Ni is not the controlling factor in the irradiation damage behavior of these materials; rather, the Mn content of the steel is a dominant factor in the irradiation-induced microstructural development of solute-related hardening features.

M.G. Burke; R.J. Stofanak; J.M. Hyde; C.A. English; W.L. Server

2002-10-09T23:59:59.000Z

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381

Friction between Ring Polymer Brushes  

E-Print Network [OSTI]

Friction between ring-polymer brushes at melt densities sliding past each other are studied using extensive course-grained molecular dynamics simulations and scaling arguments, and the results are compared to the friction between linear-polymer brushes. We show that for a velocity range spanning over three decades, the frictional forces measured for ring-polymer brushes are half the corresponding friction in case of linear brushes. In the linear-force regime, the weak inter-digitation of two ring brushes compared to linear brushes also leads to a lower number of binary collisions between the monomers of opposing brushes. At high velocities, where the thickness of the inter-digitation layer between two opposing brushes is on the order monomer size regardless of brush topology, stretched segments of ring polymers take a double-stranded conformation. As a result, monomers of the double-stranded segments collide less with the monomers of the opposing ring brush even though a similar number of monomers occupies the inter-digitation layer for ring and linear-brush bilayers. The numerical data obtained from our simulations is consistent with the proposed scaling analysis. Conformation-dependent frictional reduction observed in ring brushes can have important consequences in non-equilibrium bulk systems.

A. Erbas; J. Paturej

2015-01-07T23:59:59.000Z

382

Gauge field, strings, solitons, anomalies and the speed of life  

E-Print Network [OSTI]

It's been said that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better". Here we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this we merge techniques which have been introduced and developed in modern mathematical physics, largely by Ludvig Faddeev to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic string-like configuration in the far infrared. We observe that the energy supports topological solitons, that pertain to an anomaly in the manner how a string is framed around its inflection points. We explain how the solitons operate as modular building blocks from which folded proteins are composed. We describe crystallographic protein structures by multi-solitons with experimental precision, and investigate the non-equilibrium dynamics of proteins under varying temperature. We simulate the folding process of a protein at in vivo speed and with close to pico-scale accuracy using a standard laptop computer: With pico-biology as mathematical physics' next pursuit, things can only get better.

Antti J. Niemi

2014-07-05T23:59:59.000Z

383

Turbulent equipartitions in two dimensional drift convection  

SciTech Connect (OSTI)

Unlike the thermodynamic equipartition of energy in conservative systems, turbulent equipartitions (TEP) describe strongly non-equilibrium systems such as turbulent plasmas. In turbulent systems, energy is no longer a good invariant, but one can utilize the conservation of other quantities, such as adiabatic invariants, frozen-in magnetic flux, entropy, or combination thereof, in order to derive new, turbulent quasi-equilibria. These TEP equilibria assume various forms, but in general they sustain spatially inhomogeneous distributions of the usual thermodynamic quantities such as density or temperature. This mechanism explains the effects of particle and energy pinch in tokamaks. The analysis of the relaxed states caused by turbulent mixing is based on the existence of Lagrangian invariants (quantities constant along fluid-particle or other orbits). A turbulent equipartition corresponds to the spatially uniform distribution of relevant Lagrangian invariants. The existence of such turbulent equilibria is demonstrated in the simple model of two dimensional electrostatically turbulent plasma in an inhomogeneous magnetic field. The turbulence is prescribed, and the turbulent transport is assumed to be much stronger than the classical collisional transport. The simplicity of the model makes it possible to derive the equations describing the relaxation to the TEP state in several limits.

Isichenko, M.B.; Yankov, V.V. [Univ. of California, Santa Barbara, CA (United States). Inst. for Theoretical Physics

1995-07-25T23:59:59.000Z

384

Radiation in molecular dynamic simulations  

SciTech Connect (OSTI)

Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of Megabars to thousands of Gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The new technique passes a key test: it relaxes to a blackbody spectrum for a plasma in local thermodynamic equilibrium. This new tool also provides a method for assessing the accuracy of energy and momentum exchange models in hot dense plasmas. As an example, we simulate the evolution of non-equilibrium electron, ion, and radiation temperatures for a hydrogen plasma using the new molecular dynamics simulation capability.

Glosli, J; Graziani, F; More, R; Murillo, M; Streitz, F; Surh, M

2008-10-13T23:59:59.000Z

385

Theoretical investigation of spin-filtering in CrAs/GaAs heterostructures  

SciTech Connect (OSTI)

The electronic structure of bulk zinc-blende GaAs, zinc-blende and tetragonal CrAs, and CrAs/GaAs supercells, computed within linear muffin-tin orbital (LMTO) local spin-density functional theory, is used to extract the band alignment for the [1,0,0] GaAs/CrAs interface in dependence of the spin orientation. With the lateral lattice constant fixed to the experimental bulk GaAs value, a local energy minimum is found for a tetragonal CrAs unit cell with a longitudinal ([1,0,0]) lattice constant reduced by ?2%. Due to the identified spin-dependent band alignment, half-metallicity of CrAs no longer is a key requirement for spin-filtering. Based on these findings, we study the spin-dependent tunneling current in [1,0,0] GaAs/CrAs/GaAs heterostructures within the non-equilibrium Green's function approach for an effective tight-binding Hamiltonian derived from the LMTO electronic structure. Results indicate that these heterostructures are promising candidates for efficient room-temperature all-semiconductor spin-filtering devices.

Stickler, B. A.; Ertler, C.; Pötz, W., E-mail: walter.poetz@uni-graz.at [Institute of Physics, Karl-Franzens Universität Graz, Graz (Austria); Chioncel, L. [Institute of Physics, Theoretical Physics III, Center for Electronic Correlations and Magnetism, University of Augsburg, D-86135 Augsburg (Germany)

2013-12-14T23:59:59.000Z

386

Deceleration of Alpha Particles in the Solar Wind by Instabilities and the Rotational Force: Implications for Heating, Azimuthal Flow, and the Parker Spiral Magnetic Field  

E-Print Network [OSTI]

Protons and alpha particles in the fast solar wind are only weakly collisional and exhibit a number of non-equilibrium features, including relative drifts between particle species. Two non-collisional mechanisms have been proposed for limiting differential flow between alpha particles and protons: plasma instabilities and the rotational force. Both mechanisms decelerate the alpha particles. In this paper, we derive an analytic expression for the rate $Q_{\\mathrm{flow}}$ at which energy is released by alpha-particle deceleration, accounting for azimuthal flow and conservation of total momentum. We find that $Q_{\\mathrm{flow}} > 0 $ at $r r_{\\mathrm{crit}}$. We compare the value of $Q_{\\mathrm{flow}}$ at $r< r_{\\mathrm{crit}}$ with empirical heating rates for protons and alpha particles, denoted $Q_{\\mathrm{p}}$ and $Q_{\\alpha}$, deduced from in-situ measurements of fast-wind streams from the Helios and Ulysses spacecraft. We find that $Q_{\\mathrm{flow}}$ exceeds $Q_{\\alpha}$ at $r < 1\\,\\mathrm{AU}$, $Q_{...

Verscharen, Daniel; Bourouaine, Sofiane; Hollweg, Joseph V

2014-01-01T23:59:59.000Z

387

Fe-rich ejecta in the supernova remnant G352.7-0.1 with Suzaku  

E-Print Network [OSTI]

In this work, we present results from a $\\sim$201.6 ks observation of G352.7$-$0.1 by using the X-ray Imaging Spectrometer onboard {\\it Suzaku} X-ray Observatory. The X-ray emission from the remnant is well described by two-temperature thermal models of non-equilibrium ionization with variable abundances with a column density of $N_{\\rm H}$ $\\sim$ 3.3$\\times$10$^{22}$ cm$^{-2}$. The soft component is characterized by an electron temperature of $kT_{\\rm e}$ $\\sim$ 0.6 keV, an ionization time-scale of $\\tau$ $\\sim$ 3.4$\\times$10$^{11}$ cm$^{-3}$ s, and enhanced Si, S, Ar, and Ca abundances. The hard component has $kT_{\\rm e}$ $\\sim$ 4.3 keV, $\\tau$ $\\sim$ 8.8$\\times$10$^{9}$ cm$^{-3}$ s, and enhanced Fe abundance. The elemental abundances of Si, S, Ar, Ca, and Fe are found to be significantly higher than the solar values that confirm the presence of ejecta. We detected strong Fe K-shell emission and determined its origin to be the ejecta for the first time. The detection of Fe ejecta with a lower ionization tim...

Sezer, Aytap

2014-01-01T23:59:59.000Z

388

TRIGGERED STAR FORMATION AND DUST AROUND MID-INFRARED-IDENTIFIED BUBBLES  

SciTech Connect (OSTI)

We use Two Micron All Sky Survey, GLIMPSE, and MIPSGAL survey data to analyze the young stellar object (YSO) and warm dust distribution around several mid-infrared-identified bubbles. We identify YSOs using J-band to 8 {mu}m photometry and correlate their distribution relative to the photodissociation region (PDR; as traced by diffuse 8 {mu}m emission), which we assume to be associated with and surrounding an H II region. We find that only 20% of the sample H II regions appear to have a significant number of YSOs associated with their PDRs, implying that triggered star formation mechanisms acting on the boundary of the expanding H II region do not dominate in this sample. We also measure the temperature of dust inside 20 H II regions using 24 {mu}m and 70 {mu}m MIPSGAL images. In eight circularly symmetric sources, we analyze the temperature distribution and find shallower temperature gradients than predicted by an analytic model. Possible explanations of this shallow temperature gradient are a radially dependent grain-size distribution and/or non-equilibrium radiative processes.

Watson, C.; Mengistu, A. [Department of Physics, Manchester College, 604 East College Avenue, North Manchester, IN 46962 (United States); Hanspal, U. [Ross University School of Medicine, 630 US Highway 1, North Brunswick, NJ 08902 (United States)

2010-06-20T23:59:59.000Z

389

The Principle of Stationary Action in Biophysics: Stability in Protein Folding  

E-Print Network [OSTI]

Processes that proceed reliably from a variety of initial conditions to a unique final form, regardless of moderately changing conditions, are of obvious importance in biophysics. Protein folding is a case in point. We show that the action principle can be applied directly to study the stability of biological processes. The action principle in classical physics starts with the first variation of the action and leads immediately to the equations of motion. The second variation of the action leads in a natural way to powerful theorems that provide quantitative treatment of stability and focusing and also explain how some very complex processes can behave as though some seemingly important forces drop out. We first apply these ideas to the non-equilibrium states involved in two-state folding. We treat torsional waves and use the action principle to talk about critical points in the dynamics. For some proteins the theory resembles TST. We reach several quantitative and qualitative conclusions. Besides giving an e...

Simmons, Walter

2013-01-01T23:59:59.000Z

390

Modulation of contact resistance between metal and graphene by controlling the graphene edge, contact area, and point defects: An ab initio study  

SciTech Connect (OSTI)

A systematic first-principles non-equilibrium Green's function study is conducted on the contact resistance between a series of metals (Au, Ag, Pt, Cu, Ni, and Pd) and graphene in the side contact geometry. Different factors such as the termination of the graphene edge, contact area, and point defect in contacted graphene are investigated. Notable differences are observed in structural configurations and electronic transport characteristics of these metal-graphene contacts, depending on the metal species and aforementioned influencing factors. It is found that the enhanced chemical reactivity of the graphene due to dangling bonds from either the unsaturated graphene edge or point defects strengthens the metal-graphene bonding, leading to a considerable contact resistance reduction for weakly interacting metals Au and Ag. For stronger interacting metals Pt and Cu, a slightly reduced contact resistance is found due to such influencing factors. However, the wetting metals Ni and Pd most strongly hybridize with graphene, exhibiting negligible dependence on the above influencing factors. This study provides guidance for the optimization of metal-graphene contacts at an atomic scale.

Ma, Bo; Wen, Yanwei, E-mail: ywwen@hust.edu.cn, E-mail: bshan@mail.hust.edu.cn [State Key Laboratory of Material Processing and Die and Mould Technology and School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Gong, Cheng; Cho, Kyeongjae [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States); Chen, Rong [State Key Laboratory of Digital Manufacturing Equipment and Technology and School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Shan, Bin, E-mail: ywwen@hust.edu.cn, E-mail: bshan@mail.hust.edu.cn [State Key Laboratory of Material Processing and Die and Mould Technology and School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States)

2014-05-14T23:59:59.000Z

391

Heat conductance in nonlinear lattices at small temperature gradients  

E-Print Network [OSTI]

This paper proposes a new methodological framework within which the heat conductance in 1D lattices can be studied. The total process of heat conductance is separated into two parts where the first one is the equilibrium process at equal temperatures $T$ of both ends and the second one -- non-equilibrium with the temperature $\\Delta T$ of one end and zero temperature of the other. This approach allows significant decrease of computational time at $\\Delta T \\to 0$. The threshold temperature $T_{\\rm thr}$ is found which scales $T_{\\rm thr}(N) \\sim N^{-3}$ with the lattice size $N$ and by convention separates two mechanisms of heat conductance: phonon mechanism dominates at $T T_{\\rm thr}$. Solitons and breathers are directly visualized in numerical experiments. The problem of heat conductance in non-linear lattices in the limit $\\Delta T \\to 0$ can be reduced to the heat conductance of harmonic lattice with time-dependent stochastic rigidities determined by the equilibrium process at temperature $T$. The detailed analysis is done for the $\\beta$-FPU lattice though main results are valid for one-dimensional lattices with arbitrary potentials.

T. Yu. Astakhova; V. N. Likhachev; G. A. Vinogradov

2010-06-09T23:59:59.000Z

392

Linking Grain Boundary Structure and Composition to Intergranular Stress Corrosion Cracking of Austenitic Stainless Steels  

SciTech Connect (OSTI)

Grain boundary structure and composition is assessed in austenitic stainless steels along with its influence on intergranular stress corrosion cracking (IGSCC) in high-temperature water. Brief examples are presented illustrating effects of grain boundary character and segregation on behavior in specific light-water-reactor environments. Although grain boundary engineering can produce an increased fraction of special boundaries in austenitic stainless alloys, practical benefits depend on the boundary orientation distribution. It is critical to recognize that only coherent sigma 3s appear to be resistant to SCC and the behavior of other low sigma boundaries is uncertain. Grain boundary composition can have a dominant effect on IGSCC under certain conditions, but altered interfacial chemistry is not required for cracking. In high-potential oxidizing environments, IGSCC susceptibility is a direct function of the boundary Cr concentration. Non-equilibrium thermal segregation of Cr and Mo is often present in millannealed stainless steels and may influence cracking susceptibility. This initial grain boundary composition alters subsequent radiation-induced segregation and delays irradiation-assisted SCC susceptibility to higher doses. Other alloying elements and impurities in 300-series stainless steels have been seen to enrich grain boundaries, but few have any significant impact on IGSCC susceptibility. One exception is Si that strongly segregates during irradiation. recent results suggest that Si may accelerate crack propagation in both low- and high-potential water environments. Critical research is still needed to isolate individual grain boundary characteristics and quantitatively link to IGSCC.

Bruemmer, Stephen M.

2004-08-10T23:59:59.000Z

393

Effect of laser field and thermal stress on diffusion in laser doping of SiC  

Science Journals Connector (OSTI)

The electromagnetic field of lasers and non-equilibrium doping conditions enable laser doping of SiC with increased dopant diffusivity. Chromium, which acts as a double acceptor, has been laser-doped in SiC wafers. A thermal model is utilized to determine the temperature distribution at various depths of the wafer and a diffusion model is presented including the effects of Fickian diffusion, laser electromagnetic field and thermal stresses due to localized laser heating on the mass flux of dopant atoms. The dopant diffusivity is calculated as a function of temperature at different depths of the wafer based on measured dopant concentration profile. The maximum diffusivities achieved in this study are 4.61 × 10?10 cm2 s?1 at 2898 K and 6.92 × 10?12 cm2 s?1 at 3046 K for 6H-SiC and 4H-SiC, respectively. The maximum concentration is found to be 2.29 × 1019 cm?3 for 6H-SiC, which is two orders of magnitude higher than the reported value (3 × 1017 cm?3 solid solubility limit).

Sachin Bet; Nathaniel Quick; Aravinda Kar

2007-01-01T23:59:59.000Z

394

Fractal quantum well heterostructures for broadband light emitters  

SciTech Connect (OSTI)

We examine carrier relaxation and radiative recombination in AlGaAs based near IR and AlGaInP based visible fractal quantum well heterostructures. Through temperature dependent photoluminescence, we demonstrate that enhanced population of higher lying energy levels can be achieved by varying the thickness of the layers in the fractal heterostructurd. This distribution of carriers results in room temperature emission over a relatively broad range of wavelengths: approximately 700--855 nm for AlGaAs structures and 575--650 nm for AlGaInP structures. Spectra are compared to theoretical calculations to evaluate the non-equilibrium nature of the carrier distributions. Time resolved photoluminescence measurements demonstrate an approximately linear relationship between the radiative decay time and the layer thickness of the structure. Correspondingly, integrated luminescence measurements at room temperature reveal a factor of four increase in the light output efficiency of the structure as the fractal layer thickness is increased from 50 {angstrom} to 400 {angstrom}. The applicability of these heterostructures to broadband LEDs is discussed.

Crawford, M.H.; Gourley, P.L.; Meissner, K.E.; Sinclair, M.B.; Jones, E.D.; Chow, W.W.; Schneider, R.P. Jr.

1994-12-31T23:59:59.000Z

395

Pre-equilibrium plasma dynamics  

SciTech Connect (OSTI)

Approaches towards understanding and describing the pre-equilibrium stage of quark-gluon plasma formation in heavy-ion collisions are reviewed. Focus is on a kinetic theory approach to non-equilibrium dynamics, its extension to include the dynamics of color degrees of freedom when applied to the quark-gluon plasma, its quantum field theoretical foundations, and its relationship to both the particle formation stage at the very beginning of the nuclear collision and the hydrodynamic stage at late collision times. The usefulness of this approach to obtain the transport coefficients in the quark-gluon plasma and to derive the collective mode spectrum and damping rates in this phase are discussed. Comments are made on the general difficulty to find appropriated initial conditions to get the kinetic theory started, and a specific model is given that demonstrates that, once given such initial conditions, the system can be followed all the way through into the hydrodynamical regime. 39 refs., 7 figs. (LEW)

Heinz, U.

1986-01-01T23:59:59.000Z

396

Electron dynamics and energy dissipation in highly excited dielectrics  

Science Journals Connector (OSTI)

Abstract When dielectrics are irradiated with an ultrashort laser pulse or a swift heavy ion, the transient density of electrons in the conduction band increases considerably. This density is a crucial parameter for the subsequent behavior of the material: After ion irradiation, it influences energy dissipation to the lattice as well as the energy transport to the outer track. For the case of laser irradiation on a timescale of about hundred femtoseconds, the free-electron density increase due to irradiation also determines the further absorption of the pulse energy. Additionally, the distribution function of the excited electrons may influence energy absorption and dissipation. We study the evolution of the free-electron density and energy in laser-irradiated solids on ultrashort timescales. Our calculations also give insights to the case of irradiation with a swift heavy ion. Various theoretical approaches are applied to trace the non-equilibrium distribution function of the highly excited electronic system as well as the energy transfer to the lattice and the transport of heat and carriers to the depth of the irradiated material.

B. Rethfeld; A. Rämer; N. Brouwer; N. Medvedev; O. Osmani

2014-01-01T23:59:59.000Z

397

Lattice-gas model for active vesicle transport by molecular motors with opposite polarities  

E-Print Network [OSTI]

We introduce a multi-species lattice gas model for motor protein driven collective cargo transport on cellular filaments. We use this model to describe and analyze the collective motion of interacting vesicle cargoes being carried by oppositely directed molecular motors, moving on a single biofilament. Building on a totally asymmetric exclusion process (TASEP) to characterize the motion of the interacting cargoes, we allow for mass exchange with the environment, input and output at filament boundaries and focus on the role of interconversion rates and how they affect the directionality of the net cargo transport. We quantify the effect of the various different competing processes in terms of non-equilibrium phase diagrams. The interplay of interconversion rates, which allow for flux reversal and evaporation/deposition processes introduce qualitatively new features in the phase diagrams. We observe regimes of three-phase coexistence, the possibility of phase re-entrance and a significant flexibility in how the different phase boundaries shift in response to changes in control parameters. The moving steady state solutions of this model allows for different possibilities for the spatial distribution of cargo vesicles, ranging from homogeneous distribution of vesicles to polarized distributions, characterized by inhomogeneities or {\\it shocks}. Current reversals due to internal regulation emerge naturally within the framework of this model. We believe this minimal model will clarify the understanding of many features of collective vesicle transport, apart from serving as the basis for building more exact quantitative models for vesicle transport relevant to various {\\it in-vivo} situations.

Sudipto Muhuri; Ignacio Pagonabarraga

2010-09-09T23:59:59.000Z

398

Analysis of the heat transfer and airflow in solar chimney drying system with porous absorber  

Science Journals Connector (OSTI)

Abstract In this paper, the chimney is assembled with porous absorber for the indirect-mode solar dryer. Local thermal non-equilibrium (LTNE) exists in the porous absorber, so the double energy equations and Brinkman–Forchheimer extended Darcy model are employed to analyze the heat transfer and flow in the solar porous absorber, and the k-? turbulent model coupled with the above equations are also used to investigate the influences of the porous absorber inclination and the height of drying system on the heat transfer in the solar dryer. The specific heat capacities (?c) and thermal conductivity ks have remarkable effects on the average temperature of solar porous absorber in the drying system. The mean temperature of the higher (?c) Aluminous solar absorber is lower and the top temperature of porous absorber delays due to lower thermal conductivity ks. The inclined angle of porous absorber influences the airflow and temperature field in the solar dryer greatly. With the height of solar dryer changing from 1.41 m to 1.81 m, the higher airflow velocity and the lower temperature at chimney exit can be achieved. The simulations agree with the published experimental data. All these results should be taken into account for the promotion and application of the solar chimney dryer with porous absorber.

Wei Chen; Man Qu

2014-01-01T23:59:59.000Z

399

The operation principle of the well in quantum dot stack infrared photodetector  

SciTech Connect (OSTI)

The well in the quantum dot stack infrared photodetector (WD-QDIP) is proposed which can be operated at high temperature ?230?K. The operation principle of this device is investigated, including the carrier transport and the enhancement in the photocurrent. The WD-QDIPs with different well numbers are fabricated to study the mechanisms. It is realized that the carrier transport from the emitter to the collector in traditional quantum dot infrared photodetectors consists of two channels deduced from current-voltage characteristics and dark current activation energy at different temperatures. At temperatures below 77?K, the current transports through the InAs quantum dot channel, whereas at temperatures higher than 77?K, the current is dominated by the GaAs leakage channel. In addition, the non-equilibrium situation at low temperatures is also observed owing to the presence of photovoltaic phenomenon. The carrier distribution inside the QDs is simulated to investigate the reasons for the increase of photocurrent. Based on the simulation and the photocurrent response, the hot carrier (electron) scattering effect by the insertion of a quantum well layer is inferred as the most probable reason that lead to the enhancement of the response and regarded as the key factor to achieve high- temperature operation.

Lee, Jheng-Han; Wu, Zong-Ming [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Liao, Yu-Min; Wu, Yuh-Renn [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China); Lin, Shih-Yen [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Taipei 115299, Taiwan (China); Lee, Si-Chen, E-mail: sclee@cc.ee.ntu.edu.tw [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China)

2013-12-28T23:59:59.000Z

400

Finite-size Domains in a Membrane with Two-state Active Inclusions  

E-Print Network [OSTI]

We propose a model that leads to the formation of non-equilibrium finite-size domains in a biological membrane. Our model considers the active conformational change of the inclusions and the coupling between inclusion density and membrane curvature. Two special cases with different interactions are studied by Monte Carlo simulations. In case (i) exited state inclusions prefer to aggregate. In case (ii) ground state inclusions prefer to aggregate. When the inclusion density is not coupled to the local membrane curvature, in case (i) the typical length scale ($\\sqrt{M}$) of the inclusion clusters shows weak dependence on the excitation rate ($K_{on}$) of the inclusions for a wide range of $K_{on}$ but increases fast when $K_{on}$ becomes sufficiently large; in case (ii) $\\sqrt{M}\\sim {K_{on}}^{-{1/3}}$ for a wide range of $K_{on}$. When the inclusion density is coupled to the local membrane curvature, the curvature coupling provides the upper limit of the inclusion clusters. In case (i) (case (ii)), the formation of the inclusions is suppressed when $K_{off}$ ($K_{on}$) is sufficiently large such that the ground state (excited state) inclusions do not have sufficient time to aggregate. We also find that the mobility of an inclusion in the membrane depends on inclusion-curvature coupling. Our study suggests possible mechanisms that produce finite-size domains in biological membranes.

Chien-Hsun Chen

2005-12-06T23:59:59.000Z

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401

M-BAND IMAGING OF THE HR 8799 PLANETARY SYSTEM USING AN INNOVATIVE LOCI-BASED BACKGROUND SUBTRACTION TECHNIQUE  

SciTech Connect (OSTI)

Multi-wavelength observations/spectroscopy of exoplanetary atmospheres are the basis of the emerging exciting field of comparative exoplanetology. The HR 8799 planetary system is an ideal laboratory to study our current knowledge gap between massive field brown dwarfs and the cold 5 Gyr old solar system planets. The HR 8799 planets have so far been imaged at J- to L-band, with only upper limits available at M-band. We present here deep high-contrast Keck II adaptive optics M-band observations that show the imaging detection of three of the four currently known HR 8799 planets. Such detections were made possible due to the development of an innovative LOCI-based background subtraction scheme that is three times more efficient than a classical median background subtraction for Keck II AO data, representing a gain in telescope time of up to a factor of nine. These M-band detections extend the broadband photometric coverage out to {approx}5 {mu}m and provide access to the strong CO fundamental absorption band at 4.5 {mu}m. The new M-band photometry shows that the HR 8799 planets are located near the L/T-type dwarf transition, similar to what was found by other studies. We also confirm that the best atmospheric fits are consistent with low surface gravity, dusty, and non-equilibrium CO/CH{sub 4} chemistry models.

Galicher, Raphael; Marois, Christian [National Research Council Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Macintosh, Bruce; Konopacky, Quinn [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 (United States); Barman, Travis, E-mail: raphael.galicher@nrc-cnrc.gc.ca [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)

2011-10-01T23:59:59.000Z

402

Heat conductivity in the beta-FPU lattice. Solitons and breathers as energy carriers  

E-Print Network [OSTI]

This paper consists of two parts. The first part proposes a new methodological framework within which the heat conductivity in 1D lattices can be studied. The total process of heat conductivity is decomposed into two contributions where the first one is the equilibrium process at equal temperatures T of both lattice ends and the second -- non-equilibrium process with the temperature \\Delta T of one end and zero temperature of the other. The heat conductivity in the limit \\Delta T \\to 0 is reduced to the heat conductivity of harmonic lattice. A threshold temperature T_{thr} scales T_{thr}(N) \\sim N^{-3} with the lattice size N. Some unusual properties of heat conductivity can be exhibited on nanoscales at low temperatures. The thermodynamics of the \\beta-FPU lattice can be adequately approximated by the harmonic lattice. The second part testifies in the favor of the soliton and breather contribution to the heat conductivity in contrast to [N. Li, B. Li, S. Flach, PRL 105 (2010) 054102]. In the continuum limit the \\beta-FPU lattice is reduced to the modified Korteweg - de Vries equation with soliton and breather solutions. Numerical simulations demonstrate their high stability. New method for the visualization of moving solitons and breathers is suggested. An accurate expression for the dependence of the sound velocity on temperature is also obtained. Our results support the conjecture on the solitons and breathers contribution to the heat conductivity.

T. Yu. Astakhova; V. N. Likhachev; G. A. Vinogradov

2011-03-18T23:59:59.000Z

403

The dynamics of technology diffusion and the impacts of climate policy instruments in the decarbonisation of the global electricity sector  

Science Journals Connector (OSTI)

Abstract This paper presents an analysis of climate policy instruments for the decarbonisation of the global electricity sector in a non-equilibrium economic and technology diffusion perspective. Energy markets are driven by innovation, path-dependent technology choices and diffusion. However, conventional optimisation models lack detail on these aspects and have limited ability to address the effectiveness of policy interventions because they do not represent decision-making. As a result, known effects of technology lock-ins are liable to be underestimated. In contrast, our approach places investor decision-making at the core of the analysis and investigates how it drives the diffusion of low-carbon technology in a highly disaggregated, hybrid, global macroeconometric model, FTT:Power-E3MG. Ten scenarios to 2050 of the electricity sector in 21 regions exploring combinations of electricity policy instruments are analysed, including their climate impacts. We show that in a diffusion and path-dependent perspective, the impact of combinations of policies does not correspond to the sum of impacts of individual instruments: synergies exist between policy tools. We argue that the carbon price required to break the current fossil technology lock-in can be much lower when combined with other policies, and that a 90% decarbonisation of the electricity sector by 2050 is affordable without early scrapping.

J.-F. Mercure; H. Pollitt; U. Chewpreecha; P. Salas; A.M. Foley; P.B. Holden; N.R. Edwards

2014-01-01T23:59:59.000Z

404

Spectrally Resolved Intensities of Ultra-Dense Hot Aluminum Plasmas  

SciTech Connect (OSTI)

We present a first study of spectroscopic determination of electron temperature and density spatial profiles of aluminum K-shell line emission spectra from laser-shocked aluminum experiments performed at LULI. The radiation emitted by the aluminum plasma was dispersed with an ultra-high resolution spectrograph ({lambda}/{delta}{lambda}{approx_equal}6000). From the recorded films one can extract a set of time-integrated emission lineouts associated with the corresponding spatial region of the plasma. The observed spectra include the Ly{alpha}, He{beta}, He{gamma}, Ly{beta} and Ly{gamma} line emissions and their associated He- and Li-like satellites thus covering a photon energy range from 1700 eV to 2400 eV approximately. The data analysis rely on the ABAKO/RAPCAL computational package, which has been recently developed at the University of Las Palmas de Gran Canaria and takes into account non-equilibrium collisional-radiative atomic kinetics, Stark broadened line shapes and radiation transport calculations.

Gil, J. M.; Rodriguez, R.; Florido, R.; Rubiano, J. G.; Martel, P. [Departamento de Fisica, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria (Spain); Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Minguez, E. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Sauvan, P. [Departamento de Ingenieria Energetica, UNED, Madrid (Spain); Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Angelo, P.; Dalimier, E. [Physique Atomique dans les Plasmas Denses, LULI, CNRS-CEA-Ecole Polytechnique-Universite Paris VI, 75252 Paris cedex 05 (France); Schott, R.; Mancini, R. [Department of Physics, University of Nevada, Reno, NV 89557 (United States)

2008-10-22T23:59:59.000Z

405

New XMM-Newton observations of SNRs in the SMC  

E-Print Network [OSTI]

A complete overview of the supernova remnant (SNR) population is required to investigate their evolution and interaction with the surrounding interstellar medium in the Small Magellanic Cloud (SMC). Recent XMM-Newton observations of the SMC cover three known SNRs (DEM S5, SNR B0050-72.8, and SNR B0058-71.8), which are poorly studied and are X-ray faint. We used new multi-frequency radio-continuum surveys and new optical observations at Ha, [SII], and [OIII] wavelengths, in combination with the X-ray data, to investigate their properties and to search for new SNRs in the SMC. We used X-ray source selection criteria and found one SMC object with typical SNR characteristics (HFPK 334), that was initially detected by ROSAT. We analysed the X-ray spectra and present multi-wavelength morphological studies of the three SNRs and the new candidate. Using a non-equilibrium ionisation collisional plasma model, we find temperatures kT around 0.18 keV for the three known remnants and 0.69 keV for the candidate. The low te...

Filipovic, M D; Winkler, P F; Pietsch, W; Payne, J L; Crawford, E J; De Horta, A Y; Stootman, F H; Reaser, B E

2008-01-01T23:59:59.000Z

406

A mechanism for stickness, dealing with extreme events  

E-Print Network [OSTI]

In this letter we study how hyperbolic and non hyperbolic regions in the neighborhood of a resonant island perform a important role allowing or forbidding stickiness phenomenon around islands in conservative systems. The vicinity of the island is composed by non hyperbolic areas that almost prevent the trajectory to visit the island edge. For some specific parameters there are tiny channels embedded in the non hyperbolic area that are associated to hyperbolic fixed points present in the neighborhood of the islands. Such channels allow the trajectory to be injected in the inner portion of the vicinity. When the trajectory crosses the barrier imposed by the non hyperbolic regions, it spends a long time to abandon the surrounding of the island, since the barrier also prevents the trajectory to scape from the neighborhood of the island. In this scenario the non hyperbolic structures are the responsible for the stickiness phenomena, and more than that, the strength of the sticky effect. We reveal that those properties of the phase space allow us to manipulate the existence of extreme events (and the transport associated to it) responsible for the non equilibrium fluctuation of the system. In fact we demonstrate that monitoring very small portions of the phase space (namely $\\approx 4\\times 10^{-4}$ \\% of it) it is possible to generate a completely diffusive system eliminating long time recurrences that result from the stickiness phenomenon.

Taline Suellen Kruger; Paulo Paneque Galuzio; Thiago de Lima Prado; Sergio Roberto Lopes; José Danilo Szezech Jr; Ricardo Luiz Viana

2015-01-12T23:59:59.000Z

407

Generation of Initial Kinetic Distributions for Simulation of Long-Pulse Charged Particle Beams with High Space-Charge intensity  

SciTech Connect (OSTI)

Self-consistent Vlasov-Poisson simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel--both in terms of low-order rms (envelope) properties as well as the higher-order phase-space structure. Here, we first review broad classes of kinetic distributions commonly in use as initial Vlasov distributions in simulations of unbunched or weakly bunched beams with intense space-charge fields including: the Kapchinskij-Vladimirskij (KV) equilibrium, continuous-focusing equilibria with specific detailed examples, and various non-equilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of usual accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial kinetic distributions are constructed using transformations that preserve linear-focusing single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for non-continuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulation applications that more precisely probe intrinsic stability properties and machine performance.

Lund, Steven M.; Kikuchi, Takashi; Davidson, Ronald C.

2007-04-03T23:59:59.000Z

408

Generation of initial Vlasov distributions for simulation of charged particle beams with high space-charge intensity  

SciTech Connect (OSTI)

Self-consistent Vlasov simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel, both in terms of low-order rms (envelope) properties as well as the higher-order phase-space structure. Here, we first review broad classes of distributions commonly in use as initial Vlasov distributions in simulations of beams with intense space-charge fields including: the Kapchinskij-Vladimirskij (KV) equilibrium, continuous-focusing equilibria with specific detailed examples, and various non-equilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of usual accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial distributions are constructed using transformations that preserve linear-focusing single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for non-continuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulation applications that more precisely probe intrinsic stability properties and machine performance.

Lund, S M; Kikuchi, T; Davidson, R C

2007-04-12T23:59:59.000Z

409

Extended Fokker Planck model: properties and solutions  

E-Print Network [OSTI]

In the current paper Fokker Planck model of random walks has been extended to non conservative cases characterized by explicit dependence of diffusion and energy on time. A given generalization allows describing of such non equilibrium processes as Levy flights in a classical differential form without use of fractal PDE. Besides it takes into account mixing properties that are obligatory for a certain class of chaotic systems such as Kolmogorov K system. It was shown that an abnormal transport is a consequence of the equilibrium distortion and not stationary diffusion. The particular case of fixed boundaries was considered. According to the received solutions it was shown that a system structure can resist a weak disturbance in the vicinity of the discrete regimes, defined by a system scale and its nonlinear properties. These regimes correspond to the exponential increase of quasi regular structure fluctuations. Only fast disruption of regime is possible for other states of the system. It leads to an immediate transition to the chaos.

Sergey Kamenshchikov

2014-01-20T23:59:59.000Z

410

Thermalization, Isotropization and Elliptic Flow from Nonequilibrium Initial Conditions with a Saturation Scale  

E-Print Network [OSTI]

In this article we report on our results about the computation of the elliptic flow of the quark-gluon-plasma produced in relativistic heavy ion collisions, simulating the expansion of the fireball by solving the relativistic Boltzmann equation for the parton distribution function tuned at a fixed shear viscosity to entropy density ratio $\\eta/s$. Our main goal is to put emphasis on the role of a saturation scale in the initial gluon spectrum, which makes the initial distribution far from a thermalized one. We find that the presence of the saturation scale reduces the efficiency in building-up the elliptic flow, even if the thermalization process is quite fast $\\tau_{therm} \\approx 0.8 \\,\\rm fm/c$ and the pressure isotropization even faster $\\tau_{isotr} \\approx 0.3 \\,\\rm fm/c$. The impact of the non-equilibrium implied by the saturation scale manifests for non-central collisions and can modify the estimate of the viscosity respect to the assumption of full thermalization in $p_T$-space. We find that the estimate of $\\eta/s$ is modified from $\\eta/s \\approx 2/4\\pi$ to $\\eta/s \\approx 1/4\\pi$ at RHIC and from $\\eta/s \\approx 3/4\\pi$ to $\\eta/s \\approx 2/4\\pi$ at LHC. We complete our investigation by a study of the thermalization and isotropization times of the fireball for different initial conditions and values of $\\eta/s$ showing how the latter affects both isotropization and thermalization. Lastly, we have seen that the range of values explored by the phase-space distribution function $f$ is such that at $p_T<0.5\\, \\rm GeV$ the inner part of the fireball stays with occupation number significantly larger than unity despite the fast longitudinal expansion, which might suggest the possibility of the formation of a transient Bose-Einstein Condensate.

Marco Ruggieri; Francesco Scardina; Salvatore Plumari; Vincenzo Greco

2014-07-09T23:59:59.000Z

411

Enhancing the performance of organic light emitting diodes by using nanostructured composite films  

Science Journals Connector (OSTI)

Recent achievements on the use of nanocomposites such as nanostructured composites with a structure of nanoparticles embedded in polymers (NIP) and nanocomposites with a structure of polymers deposited on nanoporous thin films (PON) for OLEDs are presented in this report. The influence of nanooxides on the photoelectric properties of the NIPs is explained with regard to the fact that TiO2 particles usually form a type-II heterojunction with a polymer matrix, which essentially results in the separation of non-equilibrium electrons and holes. MEH-PPV luminescence quenching is strongly dependent on the nature of nanostructural particles embedded in polymer matrix. Actually, the higher quenching of the polymer fluorescence observed in the presence of titania nanoparticles proves that the transfer of the photogenerated electrons to the TiO2 is more efficient for rods. Characterisation of the nanocomposite films showed that both the current-voltage characteristics and the photoluminescent properties of the NIP nanocomposite materials were significantly enhanced in comparison with the standard polymers. OLEDs made from these layers demonstrate high photonic efficiency. For a PON-like hybrid layer of MEH-PPV/nc-TiO2, the photoluminescence enhancement was observed when the MEHPPV-PON films were excited by a 325 nm wavelength laser, and the excitation of a 470 nm wavelength light resulted in the strong polymer fluorescence quenching. Current-voltage characteristics of laminar layer devices with a structure of Ti/PON/Al-Ag in comparison with that of Ti/MEH-PPV/Al-Ag showed that the turn-on voltage of the devices was lowered considerably. Therefore, PONs are suitable for use in a reverse OLED, where the light goes out through a transparent or semi-transparent cathode; moreover, it is much easier to make ohmic contact to the metallic Ti electrode.

Nguyen Nang Dinh; Le Ha Chi; Tran Quang Trung

2011-01-01T23:59:59.000Z

412

New XMM-Newton observations of SNRs in the SMC  

E-Print Network [OSTI]

A complete overview of the supernova remnant (SNR) population is required to investigate their evolution and interaction with the surrounding interstellar medium in the Small Magellanic Cloud (SMC). Recent XMM-Newton observations of the SMC cover three known SNRs (DEM S5, SNR B0050-72.8, and SNR B0058-71.8), which are poorly studied and are X-ray faint. We used new multi-frequency radio-continuum surveys and new optical observations at Ha, [SII], and [OIII] wavelengths, in combination with the X-ray data, to investigate their properties and to search for new SNRs in the SMC. We used X-ray source selection criteria and found one SMC object with typical SNR characteristics (HFPK 334), that was initially detected by ROSAT. We analysed the X-ray spectra and present multi-wavelength morphological studies of the three SNRs and the new candidate. Using a non-equilibrium ionisation collisional plasma model, we find temperatures kT around 0.18 keV for the three known remnants and 0.69 keV for the candidate. The low temperature, low surface brightness, and large extent of the three remnants indicates relatively large ages. The emission from the new candidate (HFPK 334) is more centrally peaked and the higher temperature suggests a younger remnant. Our new radio images indicate that a pulsar wind nebulae (PWN) is possibly associated with this object. The SNRs known in the SMC show a variety of morphological structures that are relatively uncorrelated in the different wavelength bands, probably caused by the different conditions in the surrounding medium with which the remnant interacts.

M. D. Filipovic; F. Haberl; P. F. Winkler; W. Pietsch; J. L. Payne; E. J. Crawford; A. Y. De Horta; F. H. Stootman; B. E. Reaser

2008-05-02T23:59:59.000Z

413

Microscopic quantum structure of black hole and vacuum versus quantum statistical origin of gravity  

E-Print Network [OSTI]

The Planckon densely piled model of vacuum is proposed. Based on this model, the microscopic quantum structure of Schwarzschild black hole and quantum statistical origin of its gravity are studied. The cutoff of black hole horizon leads to Casimir effect inside the horizon. This effect makes the inside vacuum has less zero quantum fluctuation energy than that of outside vacuum and the spin 1/2 radiation hole excitations are resulted inside the horizon. The mean energy of the radiation hole excitations is related to the temperature decrease of the Hawking-Unruh type by the period law of the Fermion temperature greens function and a temperature difference as well as gravity are created on the horizon. A dual relation of the gravity potentials between inside and outside regions of the black hole is found. An attractor behaviour of the horizon surface is unveiled. The gravity potential inside the black hole is linear in radial coordinate and no singularity exists at the origin of the black hole, in contrast to the conventional conjecture. All the particles absorbed by the black hole have fallen down to the horizon and converted into spin 1/2 radiation quanta with the mean energy related to the Hawking-Unruh temperature, the thermodynamic equilibrium and the mechanical balance make the radiation quanta be tightly bound in the horizon. The gravitation mass $2M$ and physical mass $M$ of the black hole are calculated. The calculated entropy of the black hole is well consistent with Hawking. Outside the horizon, there exist thermodynamic non-equilibrium and mechanical non-balance which lead to an outward centrifugal energy flow and an inward gravitation energy flow. The lost vacuum energy in the negative gravitation potential region has been removed to the black hole surface to form a spherical Planckon shell with the thickness of Planckon diameter so that energy conservation is guaranteed.

Shun-Jin Wang

2014-10-28T23:59:59.000Z

414

The role of local structure in dynamical arrest  

E-Print Network [OSTI]

Amorphous solids, or glasses, are distinguished from crystalline solids by their lack of long-range structural order. At the level of two-body structural correlations, glassformers show no qualitative change upon vitrifying from a supercooled liquid. Nonetheless the dynamical properties of a glass are so much slower that it appears to take on the properties of a solid. While many theories of the glass transition focus on dynamical quantities, a solid's resistance to flow is often viewed as a consequence of its structure. Here we address the viewpoint that this remains the case for a glass. Recent developments using higher-order measures show a clear emergence of structure upon dynamical arrest in a variety of glass formers and offer the tantalising hope of a structural mechanism for arrest. However a rigorous fundamental identification of such a causal link between structure and arrest remains elusive. We undertake a critical survey of this work in experiments, computer simulation and theory and discuss what might strengthen the link between structure and dynamical arrest. We move on to highlight the relationship between crystallisation and glass-forming ability made possible by this deeper understanding of the structure of the liquid state, and emphasize the potential to design materials with optimal glassforming and crystallisation ability, for applications such as phase-change memory. We then consider aspects of the phenomenology of glassy systems where structural measures have yet to make a large impact, such as polyamorphism (the existence of multiple liquid states), aging (the time-evolution of non-equilibrium materials below their glass transition) and the response of glassy materials to external fields such as shear.

C. Patrick Royall; Stephen R. Williams

2014-05-22T23:59:59.000Z

415

CHARACTERIZING TRANSITION TEMPERATURE GAS IN THE GALACTIC CORONA  

SciTech Connect (OSTI)

We present a study of the properties of the transition temperature (T {approx} 10{sup 5} K) gas in the Milky Way corona, based on the measurements of O VI, N V, C IV, Si IV, and Fe III absorption lines seen in the far-ultraviolet spectra of 58 sight lines to extragalactic targets, obtained with the Far-Ultraviolet Spectroscopic Explorer and the Space Telescope Imaging Spectrograph. In many sight lines the Galactic absorption profiles show multiple components, which are analyzed separately. We find that the highly ionized atoms are distributed irregularly in a layer with a scale height of about 3 kpc, which rotates along with the gas in the disk, without an obvious gradient in the rotation velocity away from the Galactic plane. Within this layer the gas has randomly oriented velocities with a dispersion of 40-60 km s{sup -1}. On average the integrated column densities are log N(O VI) = 14.3, log N(N V) = 13.5, log N(C IV) = 14.2, log N(Si IV) = 13.6, and log N(Fe III) = 14.2, with a dispersion of just 0.2 dex in each case. In sight lines around the Galactic center and Galactic north pole, all column densities are enhanced by a factor {approx}2, while at intermediate latitudes in the southern sky there is a deficit in N(O VI) of about a factor of two, but no deficit for the other ions. We compare the column densities and ionic ratios to a series of theoretical predictions: collisional ionization equilibrium, shock ionization, conductive interfaces, turbulent mixing, thick disk supernovae, static non-equilibrium ionization (NIE) radiative cooling, and an NIE radiative cooling model in which the gas flows through the cooling zone. None of these models can fully reproduce the data, but it is clear that NIE radiative cooling is important in generating the transition temperature gas.

Wakker, Bart P.; Savage, Blair D. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Fox, Andrew J. [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Benjamin, Robert A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore MD 21218 (United States); Shapiro, Paul R., E-mail: wakker@astro.wisc.edu, E-mail: savage@astro.wisc.edu, E-mail: afox@stsci.edu, E-mail: benjamir@uww.edu, E-mail: shapiro@astro.as.utexas.edu [University of Texas at Austin, Department of Astronomy, Austin, TX 78712 (United States)

2012-04-20T23:59:59.000Z

416

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the previous research, the reference point of oxygen occupancy was determined and verified. In the current research, the oxygen occupancy was investigated at 1200 C as a function of oxygen activity and compared with that at 1000 C. The cause of bumps at about 200 C was also investigated by using different heating and cooling rates during TGA. The fracture toughness of LSFT and dual phase membranes at room temperature is an important mechanical property. Vicker's indentation method was used to evaluate this toughness. Through this technique, a K{sub Ic} (Mode-I Fracture Toughness) value is attained by means of semi-empirical correlations between the indentation load and the length of the cracks emanating from the corresponding Vickers indentation impression. In the present investigation, crack propagation behavior was extensively analyzed in order to understand the strengthening mechanisms involved in the non-transforming La based ceramic composites. Cracks were generated using Vicker's indenter and used to identify and evaluate the toughening mechanisms involved. Preliminary results of an electron microscopy study of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Modeling of the isotopic transients on operating membranes (LSCrF-2828 at 900 C) and a ''frozen'' isotope profile have been analyzed in conjunction with a 1-D model to reveal the gradient in oxygen diffusivity through the membrane under conditions of high chemical gradients.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-08-01T23:59:59.000Z

417

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the current research, the electrical conductivity and Seebeck coefficient were measured as a function of temperature in air. Based on these measurements, the charge carrier concentration, net acceptor dopant concentration, activation energy of conduction and mobility were estimated. The studies on the fracture toughness of the LSFT and dual phase membranes at room temperature have been completed and reported previously. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affects the mechanical properties. To study the effect of temperature on the membranes when exposed to an inert environment, the membranes (LAFT and Dual phase) were heat treated at 1000 C in air and N{sub 2} atmosphere and hardness and fracture toughness of the membranes were studied after the treatment. The indentation method was used to find the fracture toughness and the effect of the heat treatment on the mechanical properties of the membranes. Further results on the investigation of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appears to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model will serve to study ''frozen'' profiles in patterned or composite membranes.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-11-01T23:59:59.000Z

418

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was observed in the N{sub 2} treated LSFT samples. Further results to investigate the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Recent results on transient kinetic data are presented. The 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model is used to study ''frozen'' profiles in patterned or composite membranes.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-02-01T23:59:59.000Z

419

Vacuum quantum fluctuation energy in expanding universe and dark energy  

E-Print Network [OSTI]

This article is based on the Planckon densely piled vacuum model and the principle of cosmology. With the Planck era as initial conditions and including the early inflation, we have solved the Einstein-Friedmann equations to describe the evolution of the universe. The results are: 1) the ratio of the dark energy density to the vacuum quantum fluctuation energy density is $\\frac{{{\\rho }_{de}}}{{{\\rho }_{vac}}}\\sim{{(\\frac{{{t}_{P}}}{{{T}_{0}}})}^{2}}\\sim{{10}^{-122}} $; 2) at the inflation time ${{t}_{\\inf }}={{10}^{-35}}s$, the calculated universe radiation energy density is $\\rho ({{t}_{\\inf }})\\sim{{10}^{-16}}{{\\rho }_{vac}}$ and the corresponding temperature is ${{E}_{c}}\\sim{{10}^{15}}GeV$ consistent with the GUT phase transition temperature; 3) the expanding universe with vacuum as its environment is a non-equilibrium open system constantly exchanging energy with vacuum; during its expansion, the Planckons in the universe lose quantum fluctuation energy and create the cosmic expansion quanta-cosmons, the energy of cosmons is the lost part of the vacuum quantum fluctuation energy and contributes to the universe energy with the calculated value ${{E}_{\\cos mos}}={{10}^{22}}{{M}_{\\otimes }}{{c}^{2}}$ (where ${{M}_{\\otimes }}$ is solar mass); 4) the total energy of the universe, namely the negative gravity energy plus the positive universe energy is zero; 5) the negative gravity potential and the gravity acceleration related to the creation of cosmons are derived with the nature of outward repulsive force, indicating that the cosmon may be the candidate of the dark energy quantum; 6) both the initial Planck era solution and the infinite asymptotic solution of the Einstein-Friedman equations are unstable: the former tends to expand and the latter tends to shrink, so that the Einstein-Friedman universe will undergo a cyclic evolution of successive expansion and shrinking.

Shun-Jin Wang

2014-10-27T23:59:59.000Z

420

White noise approach to the low density limit of a quantum particle in a gas  

E-Print Network [OSTI]

The white noise approach to the investigation of the dynamics of a quantum particle interacting with a dilute and in general non-equilibrium gaseous environment in the low density limit is outlined. The low density limit is the kinetic Markovian regime when only pair collisions (i.e., collisions of the test particle with one particle of the gas at one time moment) contribute to the dynamics. In the white noise approach one first proves that the appropriate operators describing the gas converge in the sense of appropriate matrix elements to certain operators of quantum white noise. Then these white noise operators are used to derive quantum white noise and quantum stochastic equations describing the approximate dynamics of the total system consisting of the particle and the gas. The derivation is given ab initio, starting from the exact microscopic quantum dynamics. The limiting dynamics is described by a quantum stochastic equation driven by a quantum Poisson process. This equation then applied to the derivation of quantum Langevin equation and linear Boltzmann equation for the reduced density matrix of the test particle. The first part of the paper describes the approach which was developed by L. Accardi, I.V. Volovich and the author and uses the Fock-antiFock (or GNS) representation for the CCR algebra of the gas. The second part presents the approach to the derivation of the limiting equations directly in terms of the correlation functions, without use of the Fock-antiFock representation. This approach simplifies the derivation and allows to express the strength of the quantum number process directly in terms of the one-particle $S$-matrix.

Alexander Pechen

2006-07-19T23:59:59.000Z

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421

Second Law of Thermodynamics, Macroscopic Observables within Boltzmann's Principle but without Thermodynamic Limit  

E-Print Network [OSTI]

Boltzmann's principle S=k ln W allows to extend equilibrium thermo-statistics to ``Small'' systems without invoking the thermodynamic limit. The clue is to base statistical probability on ensemble averaging and not on time averaging. It is argued that due to the incomplete information obtained by macroscopic measurements thermodynamics handles ensembles or finite-sized sub-manifolds in phase space and not single time-dependent trajectories. Therefore, ensemble averages are the natural objects of statistical probabilities. This is the physical origin of coarse-graining which is not anymore a mathematical ad hoc assumption. From this concept all equilibrium thermodynamics can be deduced quite naturally including the most sophisticated phenomena of phase transitions for ``Small'' systems. Boltzmann's principle is generalized to non-equilibrium Hamiltonian systems with possibly fractal distributions ${\\cal{M}}$ in 6N-dim. phase space by replacing the conventional Riemann integral for the volume in phase space by its corresponding box-counting volume. This is equal to the volume of the closure $\\bar{\\cal{M}}$. With this extension the Second Law is derived without invoking the thermodynamic limit. The irreversibility in this approach is due to the replacement of the phase-space volume by the volume of its closure $\\bar{\\cal{M}}$. The physical reason for this replacement is that macroscopic measurements cannot distinguish ${\\cal{M}}$ from $\\bar{\\cal{M}}$. Whereas the former is not changing in time due to Liouville's theorem, the volume of the closure can be larger. In contrast to conventional coarse graining the box-counting volume is defined in the limit of infinite resolution. I.e. there is no artificial loss of information.

D. H. E. Gross

2001-01-18T23:59:59.000Z

422

EXPLORING TRANSITIONS OF SPACE PLASMAS OUT OF EQUILIBRIUM  

SciTech Connect (OSTI)

Space plasmas from the solar wind to planetary magnetospheres and the outer heliosphere are systems in stationary states out of equilibrium. Empirical kappa distributions, which naturally emerge from Tsallis Statistics, successfully describe these space plasmas. The Tsallis formalism offers a solid statistical foundation and provides a set of proven tools for understanding these distributions, including a consistent definition of temperature-the physical temperature, which characterizes the non-equilibrium stationary states. Here, we develop a measure of the 'thermodynamic distance' of stationary states away from equilibrium. The stationary states are labeled by the value of the entropic q-index, lying in a spectrum from q = 1 (equilibrium) to the maximum value of q, which specifies the furthest possible stationary state from equilibrium. We call this the 'q-frozen state', because as a system approaches this state, it behaves analogously to when its temperature approaches absolute zero. We also introduce a novel isothermal procedure that describes a system's transition into different stationary states by varying the q-index, and show how the variation of temperature can be realized using an 'iso-metastability' procedure, in which the system remains in a fixed stationary state. These innovations allow a generalization of the zeroth law of thermodynamics to cover stationary states out of equilibrium. By expressing the entropy in terms of the q-index, we show the detailed paths by which the transition of stationary states evolves toward equilibrium following the dynamics of a characteristic difference equation along the q-indices. This naturally exhibits certain stationary states out of equilibrium that are frequently observed in space plasmas.

Livadiotis, G.; McComas, D. J. [Southwest Research Institute, San Antonio, TX 78238 (United States)

2010-05-01T23:59:59.000Z

423

Multidimensional Supernova Simulations with Approximative Neutrino Transport I. Neutron Star Kicks and the Anisotropy of Neutrino-Driven Explosions in Two Spatial Dimensions  

E-Print Network [OSTI]

By means of two-dimensional (2D) simulations we study hydrodynamic instabilities during the first seconds of neutrino-driven supernova explosions, using a PPM hydrodynamics code, supplemented with a gray, non-equilibrium approximation of radial neutrino transport. We consider three 15 solar mass progenitors with different structures and one rotating model, in which we replace the dense core of the newly formed neutron star (NS) by a contracting inner grid boundary, and trigger neutrino-driven explosions by systematically varying the neutrino fluxes emitted at this boundary. Confirming more idealized studies as well as supernova simulations with spectral transport, we find that random seed perturbations can grow by hydrodynamic instabilities to a globally asymmetric mass distribution, leading to a dominance of dipole (l=1) and quadrupole (l=2) modes in the explosion ejecta. Anisotropic gravitational and hydrodynamic forces are found to accelerate the NS on a timescale of 2-3 seconds. Since the explosion anisotropies develop chaotically, the magnitude of the corresponding kick varies stochastically in response to small differences in the fluid flow. Our more than 70 models separate into two groups, one with high and the other with low NS velocities and accelerations after 1s of post-bounce evolution, depending on whether the l=1 mode is dominant in the ejecta or not. This leads to a bimodality of the distribution when the NS velocities are extrapolated to their terminal values. The fast group has an average velocity of about 500 km/s and peak values in excess of 1000 km/s. Establishing a link to the measured distribution of pulsar velocities, however, requires a much larger set of calculations and ultimately 3D modeling. (abridged)

L. Scheck; K. Kifonidis; H. -Th. Janka; E. Mueller

2006-01-13T23:59:59.000Z

424

Closed time path approach to the Casimir energy in real media  

E-Print Network [OSTI]

The closed time path formalism is applied, in the framework of open quantum systems, to study the time evolution of the expectation value of the energy-momentum tensor of a scalar field in the presence of real materials. We analyze quantum fluctuations in a fully non-equilibrium scenario, when the scalar field is interacting with the polarization degrees of freedom of matter, described as quantum Brownian particles. A generalized analysis was done for two types of couplings between the field and the material. On the one hand, we considered a bilinear coupling, and on the other hand, a (more realistic) current-type coupling as in the case of the electromagnetic field interacting with matter. We considered the high temperature limit for the field, keeping arbitrary temperatures for each part of the volume elements of the material. We obtained a closed form for the Hadamard propagator, which let us study the dynamical evolution of the expectations values of the energy-momentum tensor components from the initial time. We showed that two contributions always take place in the transient evolution: one of these is associated to the material and the other one is only associated to the field. Transient features were studied and the long-time limit was derived in several cases. We proved that in the steady situation of a field in n + 1 dimensions, the material always contribute unless is non-dissipative. Conversely, the proper field contribution vanishes unless the material is non-dissipative or, moreover, at least for the 1 + 1 case, if there are regions without material. We conclude that any steady quantization scheme in 1 + 1 dimensions must consider both contributions and we argue why these results are physically expected from a dynamical point of view, and also could be valid for higher dimensions based on the expected continuity between the non-dissipative and real material cases.

Adrian E. Rubio Lopez; Fernando C. Lombardo

2014-04-28T23:59:59.000Z

425

Half-metallicity and stability of the rock salt BaC and SrC (111) surfaces: A density functional study  

SciTech Connect (OSTI)

The electronic structure and magnetic properties of relaxed (111) surfaces of the alkaline-earth monocarbides BaC and SrC in the stable rock salt structure, are calculated on the basis of first principle density functional theory within the framework of self-consistent field plane wave pseudo-potential method, using the generalized gradient approximation for the exchange-correlation functional. The results of this study reveal that the C-terminated (111) surfaces retain the bulk half-metallic property in both BaC and SrC. The half-metallicity of the C-terminated BaC surface is found to be more robust compared to the bulk BaC due to the larger half-metallic energy gap. In contrast, the half-metallic energy gap of the C-terminated SrC surface is found to be smaller than that of the bulk. The Ba-terminated surface of BaC and the Sr-terminated surface of SrC, however, lose their bulk half-metallicity due to the formation of surface states in the majority spin band gap. The calculations also show that the atomic magnetic moments at the half-metallic C-terminated surfaces in both BaC and SrC increase considerably with respect to the corresponding bulk values, which is explained in terms of an increase in the number of unpaired 2p electrons of the carbon atom at the surface. We also discuss the stability of the surfaces via the calculated bulk formation energies. The bulk formation energies for both BaC and SrC in the rock salt structure are found to be positive, which indicate that the surfaces are not stable at normal pressure and temperature conditions, and non-equilibrium growth techniques may be required for the realization of BaC and SrC thin films.

Tabatabaeifar, A. H.; Davatolhagh, S., E-mail: davatolhagh@susc.ac.ir; Foroughpour, M. [Department of Physics, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

2013-12-07T23:59:59.000Z

426

Past and present of nuclear matter  

SciTech Connect (OSTI)

The subject of nuclear matter is interesting for many fields of physics ranging from condensed matter to lattice QCD. Knowing its properties is important for our understanding of neutron stars, supernovae and cosmology. Experimentally, we have the most precise information on ground state nuclear matter from the mass formula and from the systematics of monopole vibrations. This gives us the ground state density, binding energy and the compression modulus k at ground state density. However, those methods can not be extended towards the regime we are most interested in, the regime of high density and high temperature. Additional information can be obtained from the observation of neutron stars and of supernova explosions. In both cases information is limited by the rare events that nature provides for us. High energy heavy ion collisions, on the other hand, allow us to perform controlled experiments in the laboratory. For a very short period in time we can create a system that lets us study nuclear matter properties. Density and temperature of the system depend on the mass of the colliding nuclei, on their energy and on the impact parameter. The system created in nuclear collisions has at best about 200 constituents not even close to infinite nuclear matter, and it lasts only for collision times of {approx} 10{sup {minus}22}sec, not an ideal condition for establishing any kind of equilibrium. Extended size and thermal and chemical equilibrium, however, axe a priori conditions of nuclear matter. As a consequence we need realistic models that describe the collision dynamics and non-equilibrium effects in order to relate experimental observables to properties of nuclear matter. The study of high energy nuclear collisions started at the Bevalac. I will try to summarize the results from the Bevalac studies, the highlights of the continuing program, and extension to higher energies without claiming to be complete.

Ritter, H.G.

1994-05-01T23:59:59.000Z

427

PROCEEDINGS OF RIKEN/BNL RESEARCH CENTER WORKSHOP, EQUILIBRIUM AND NON-EQUILIBRIM ASPECTS OF HOT, DENSE QCD, VOLUME 28.  

SciTech Connect (OSTI)

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven, beginning operation this year, and the Large Hadron Collider (LHC) at CERN, beginning operation {approximately}2005, will provide an unprecedented range of energies and luminosities that will allow us to probe the Gluon-Quark plasma. At RHIC and LHC, at central rapidity typical estimates of energy densities and temperatures are e * 1-10 GeV/fm3 and T0 * 300 - 900 MeV. Such energies are well above current estimates for the GQ plasma. Initially, this hot, dense plasma is far from local thermal equilibrium, making the theoretical study of transport phenomena, kinetic and chemical equilibration in dense and hot plasmas, and related issues a matter of fundamental importance. During the last few years a consistent framework to study collective effects in the Gluon-Quark plasma, and a microscopic description of transport in terms of the hard thermal (and dense) loops resummation program has emerged. This approach has the potential of providing a microscopic formulation of transport, in the regime of temperatures and densities to be achieved at RHIC and LHC. A parallel development over the last few years has provided a consistent formulation of non-equilibrium quantum field theory that provides a real-time description of phenomena out of equilibrium. Novel techniques including non-perturbative approaches and the dynamical renormalization group techniques lead to new insights into transport and relaxation. A deeper understanding of collective.excitations and transport phenomena in the GQ plasma could lead to recognize novel potential experimental signatures. New insights into small-c physics reveals a striking similarity between small-c and hard thermal loops, and novel real-time numerical simulations have recently studied the parton distributions and their thermalizations in the initial stages of a heavy ion collision.

De Vega, H.J.; Boyanovsky, D. [and others

2000-07-17T23:59:59.000Z

428

PROCEEDINGS OF RIKEN/BNL RESEARCH CENTER WORKSHOP, EQUILIBRIUM AND NON-EQUILIBRIM ASPECTTS OF HOT, DENSE QCD, VOLUME 28.  

SciTech Connect (OSTI)

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven, beginning operation this year, and the Large Hadron Collider (LHC) at CERN, beginning operation {approximately}2005, will provide an unprecedented range of energies and luminosities that will allow us to probe the Gluon-Quark plasma. At RHIC and LHC, at central rapidity typical estimates of energy densities and temperatures are e * 1-10 GeV/fm3 and T0 * 300 - 900 MeV. Such energies are well above current estimates for the GQ plasma. Initially, this hot, dense plasma is far from local thermal equilibrium, making the theoretical study of transport phenomena, kinetic and chemical equilibration in dense and hot plasmas, and related issues a matter of fundamental importance. During the last few years a consistent framework to study collective effects in the Gluon-Quark plasma, and a microscopic description of transport in terms of the hard thermal (and dense) loops resummation program has emerged. This approach has the potential of providing a microscopic formulation of transport, in the regime of temperatures and densities to be achieved at RHIC and LHC. A parallel development over the last few years has provided a consistent formulation of non-equilibrium quantum field theory that provides a real-time description of phenomena out of equilibrium. Novel techniques including non-perturbative approaches and the dynamical renormalization group techniques lead to new insights into transport and relaxation. A deeper understanding of collective.excitations and transport phenomena in the GQ plasma could lead to recognize novel potential experimental signatures. New insights into small-c physics reveals a striking similarity between small-c and hard thermal loops, and novel real-time numerical simulations have recently studied the parton distributions and their thermalizations in the initial stages of a heavy ion collision.

DE VEGA,H.J.; BOYANOVSKY,D. [and others

2000-07-17T23:59:59.000Z

429

MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization  

SciTech Connect (OSTI)

The power of magnetic resonance imaging (MRI) is its ability to image the internal structure of optically opaque samples and provide detailed maps of a variety of important parameters, such as density, diffusion, velocity and temperature. However, one of the fundamental limitations of this technique is its inherent low sensitivity. For example, the low signal to noise ratio (SNR) is particularly problematic for imaging gases in porous materials due to the low density of the gas and the large volume occluded by the porous material. This is unfortunate, as many industrially relevant chemical reactions take place at gas-surface interfaces in porous media, such as packed catalyst beds. Because of this severe SNR problem, many techniques have been developed to directly increase the signal strength. These techniques work by manipulating the nuclear spin populations to produce polarized} (i.e., non-equilibrium) states with resulting signal strengths that are orders of magnitude larger than those available at thermal equilibrium. This dissertation is concerned with an extension of a polarization technique based on the properties of parahydrogen. Specifically, I report on the novel use of heterogeneous catalysis to produce parahydrogen induced polarization and applications of this new technique to gas phase MRI and the characterization of micro-reactors. First, I provide an overview of nuclear magnetic resonance (NMR) and how parahydrogen is used to improve the SNR of the NMR signal. I then present experimental results demonstrating that it is possible to use heterogeneous catalysis to produce parahydrogen-induced polarization. These results are extended to imaging void spaces using a parahydrogen polarized gas. In the second half of this dissertation, I demonstrate the use of parahydrogen-polarized gas-phase MRI for characterizing catalytic microreactors. Specifically, I show how the improved SNR allows one to map parameters important for characterizing the heat and mass transport in a heterogeneous catalyst bed. This is followed by appendices containing detailed information regarding the design and use of my experimental setup.

Burt, Scott R; Burt, Scott R.

2008-06-25T23:59:59.000Z

430

In Situ Heating of the 2007 May 19 CME Ejecta Detected by Stereo/PLASTIC and ACE  

Science Journals Connector (OSTI)

In situ measurements of ion charge states can provide unique insight into the heating and evolution of coronal mass ejections (CMEs) when tested against realistic non-equilibrium ionization modeling. In this work, we investigate the representation of the CME magnetic field as an expanding spheromak configuration, where the plasma heating is prescribed by the choice of anomalous resistivity and the spheromak dynamics. We chose as a test case the 2007 May 19 CME observed by STEREO and ACE. The spheromak is an appealing physical model, because the location and degree of heating are fixed by the choice of anomalous resistivity and the spheromak expansion rate which we constrain with observations. This model can provide the heating required between 1.1R ? and Earth's orbit to produce charge states observed in the CME flux rope. However, this source of heating in the spheromak alone has difficulty accounting for the rapid heating to Fe8-Fe11+ at lower heights, as observed in STEREO EUVI due to the rapid radiative cooling that occurs at the high densities involved. Episodes of heating and cooling clearly unrelated to spheromak expansion are observed prior to the eruption, and presumably still play a role during the eruption itself. Spheromak heating is also not capable of reproducing the high Fe charge states (Fe16+ and higher) seen in situ exterior to the flux rope in this CME. Thus, while the spheromak configuration may be a valid model for the magnetic topology, other means of energization are still required to provide much of the rapid heating observed.

Cara E. Rakowski; J. Martin Laming; Maxim Lyutikov

2011-01-01T23:59:59.000Z

431

DEGRADATION ISSUES IN SOLID OXIDE CELLS DURING HIGH TEMPERATURE ELECTROLYSIS  

SciTech Connect (OSTI)

Idaho National Laboratory (INL) is performing high-temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells (SOECs). The project goals are to address the technical and degradation issues associated with the SOECs. This paper provides a summary of various ongoing INL and INL sponsored activities aimed at addressing SOEC degradation. These activities include stack testing, post-test examination, degradation modeling, and a list of issues that need to be addressed in future. Major degradation issues relating to solid oxide fuel cells (SOFC) are relatively better understood than those for SOECs. Some of the degradation mechanisms in SOFCs include contact problems between adjacent cell components, microstructural deterioration (coarsening) of the porous electrodes, and blocking of the reaction sites within the electrodes. Contact problems include delamination of an electrode from the electrolyte, growth of a poorly (electronically) conducting oxide layer between the metallic interconnect plates and the electrodes, and lack of contact between the interconnect and the electrode. INL’s test results on high temperature electrolysis (HTE) using solid oxide cells do not provide a clear evidence whether different events lead to similar or drastically different electrochemical degradation mechanisms. Post-test examination of the solid oxide electrolysis cells showed that the hydrogen electrode and interconnect get partially oxidized and become non-conductive. This is most likely caused by the hydrogen stream composition and flow rate during cool down. The oxygen electrode side of the stacks seemed to be responsible for the observed degradation due to large areas of electrode delamination. Based on the oxygen electrode appearance, the degradation of these stacks was largely controlled by the oxygen electrode delamination rate. University of Utah (Virkar) has developed a SOEC model based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. This model is under continued development. It shows that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, within the electrolyte. The chemical potential within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just under the oxygen electrode (anode)/electrolyte interface, leading to electrode delamination. This theory is being further refined and tested by introducing some electronic conduction in the electrolyte.

J. E. O'Brien; C. M. Stoots; V. I. Sharma; B. Yildiz; A. V. Virkar

2010-06-01T23:59:59.000Z

432

DEGRADATION ISSUES IN SOLID OXIDE CELLS DURING HIGH TEMPERATURE ELECTROLYSIS  

SciTech Connect (OSTI)

Idaho National Laboratory (INL) is performing high-temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells (SOECs). The project goals are to address the technical and degradation issues associated with the SOECs. This paper provides a summary of various ongoing INL and INL sponsored activities aimed at addressing SOEC degradation. These activities include stack testing, post-test examination, degradation modeling, and a list of issues that need to be addressed in future. Major degradation issues relating to solid oxide fuel cells (SOFC) are relatively better understood than those for SOECs. Some of the degradation mechanisms in SOFCs include contact problems between adjacent cell components, microstructural deterioration (coarsening) of the porous electrodes, and blocking of the reaction sites within the electrodes. Contact problems include delamination of an electrode from the electrolyte, growth of a poorly (electronically) conducting oxide layer between the metallic interconnect plates and the electrodes, and lack of contact between the interconnect and the electrode. INL's test results on high temperature electrolysis (HTE) using solid oxide cells do not provide a clear evidence whether different events lead to similar or drastically different electrochemical degradation mechanisms. Post-test examination of the solid oxide electrolysis cells showed that the hydrogen electrode and interconnect get partially oxidized and become non-conductive. This is most likely caused by the hydrogen stream composition and flow rate during cool down. The oxygen electrode side of the stacks seemed to be responsible for the observed degradation due to large areas of electrode delamination. Based on the oxygen electrode appearance, the degradation of these stacks was largely controlled by the oxygen electrode delamination rate. University of Utah (Virkar) has developed a SOEC model based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. This model is under continued development. It shows that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, within the electrolyte. The chemical potential within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just under the oxygen electrode (anode)/electrolyte interface, leading to electrode delamination. This theory is being further refined and tested by introducing some electronic conduction in the electrolyte.

M. S. Sohal; J. E. O'Brien; C. M. Stoots; V. I. Sharma; B. Yildiz; A. Virkar

2012-02-01T23:59:59.000Z

433

Comprehensive modeling study analyzing the insights of the NO–NO2 conversion process in current diesel engines  

Science Journals Connector (OSTI)

Abstract Multiple researches have focused on reducing the \\{NOx\\} emissions and the greatest results have been achieved when lowering the combustion temperature by employing massive exhaust gas recirculation rates (LTC). Despite this benefit, a substantial increase in the NO2 contribution to the \\{NOx\\} emissions has also been observed, which is the most harmful specie and is important for the design and positioning of the after-treatment devices. To understand how NO2 behaves and how it contributes to the total \\{NOx\\} (NO2/NOx), not only under LTC but also for CDC conditions, a stepwise computational research study was performed with Chemkin Pro software, due to the complexity of isolating the different phenomena studied, to analyze: (1) general equilibrium conditions and (2) the influence of typical diesel engine phenomena (combustion and cooling effects) under non-equilibrium conditions. The results obtained under equilibrium state confirm the theoretical guidelines established for the NO2 formation process. When considering a combustion process (HCCI-like mode), the previous results were corroborated as well as the fact that only poor or slow combustion processes are responsible for the NO2 formation. Additionally, it reflected a cyclic process between NO and NO2, or in other words, it is suffice to just concentrate on NO to be able to predict NO2. Finally, the results yield after analyzing some cooling effects, inherent to how diesel engines work (the expansion stroke, dilution of combustion products with the rest of in-cylinder charge and the one caused by wall impingement), reflect that: (1) the dilution effect explains the 10% of the NO2/NOx ratio under CDC conditions and (2) the coupling of the dilution with the expansion stroke cooling effects can explain the NO2 increase typical of LTC conditions. These results were also supported by some experiments performed in a single-cylinder diesel engine. Consequently, the cooling effect caused by dilution should be considered when modeling the NO2 formation just like the expansion stroke.

J. Benajes; J.J. López; R. Novella; P. Redón

2014-01-01T23:59:59.000Z

434

High temperature corrosion research at the Albany Research Center  

SciTech Connect (OSTI)

The Severe Environment Corrosion and Erosion Research Facility (SECERF) at the Albany Research Center is operational. SECERF consists of 6 modules that share the availability of up to 10 different gases to produce environments for high temperature corrosion and erosion research. Projects to be conducted in the modules include: corrosion sensors for fossil energy systems, thermal gradient effects on high temperature corrosion, the development of sulfidation resistant alloys, determination of the effects of ash on the corrosion of metals and alloys in coal and waste combustion and coal gasification environments, high temperature erosion-corrosion of metals, and molten slag effects on refractories. Results from two areas, the effect of ash deposits on alloy corrosion and thermal gradient effects on the corrosion of metals, will be highlighted. Ash produced in coal gasifiers, coal combustors, and waste combustors, when deposited on metal surfaces, provides sites for corrosion attack and contributes chemical species that participate in the corrosion reaction. Results are presented for the corrosion of 304L stainless steel, that was either uncoated or coated with ash or with ash containing NaCl or Na2SO4, in air-water vapor mixtures at 600 C. The presence of high heat fluxes and temperature gradients in many fossil energy systems creates the need for an understanding of their effects on corrosion and oxidation. Such information would be useful for both improved alloy design and for better translation of isothermal laboratory results to field use. Temperature gradients in a solid oxide result in two changes that modify diffusion within the oxide. The first is when a gradient in point defect concentration is created within the oxide, for example, where more vacancies are expected at a higher temperature. The second change is when the presence of a temperature gradient biases the diffusion jump of an atom. Results of tests are presented for cobalt with metal surface temperatures of approximately 920-950 C in N2 plus 1-10 vol% O2 environments with a heat flux of about 40 kW/m2. Non-equilibrium thermodynamics were used to develop oxidation rate equations in temperature gradients that were combined with point defect information of CoO to predict oxidation rates.

Covino, Bernard S., Jr.; Holcomb, Gordon R.; Russell, James H.; Cramer, Stephen D.; Bullard, Sophie J.; Ziomek-Moroz, Margaret; Matthes, Steven A.; Chinn, R.E.

2002-01-01T23:59:59.000Z

435

Theory of Many-Particle Systems. I  

Science Journals Connector (OSTI)

This is the first of a series of papers dealing with many-particle systems from a unified, nonperturbative point of view. It contains derivations and discussions of various field-theoretical techniques which will be applied in subsequent papers. In a short introduction the general method of approach is summarized, and its relationship to other field-theoretic problems indicated. In the second section the macroscopic properties of the spectra of many-particle systems are described. Asymptotic evaluations are performed which characterize these macroscopic features in terms of intensive parameters, and the relationship of these parameters to thermodynamics is discussed. The special characteristics of the ground state are shown to follow as a limiting case of the asymptotic evaluations. The third section is devoted to the time-dependent field correlation functions, or Green's functions, which describe the microscopic behavior of a multiparticle system. These functions are defined, and related to intensive macroscopic variables when the energy and number of particles are large. Spectral representations and other properties of various one-particle Green's functions are derived. In the fourth section the treatment of non-equilibrium processes is considered. As a particular example, the electromagnetic properties of a system are expressed in terms of the special two-particle Green's function which describes current correlation. The discussion yields specifically a fluctuation-dissipation theorem, a sum rule for conductivity, and certain dispersion relations. The fifth section deals with the differential equations which determine the Green's functions. The boundary conditions that characterize the Green's function equations are exhibited without reference to adiabatic decoupling. A method for solving the equations approximately, by treating the correlations among successively larger numbers of particles, is considered. The first approximation in this sequence is shown to yield a generalized Hartree-like equation. A related, but rigorous, identity for the single-particle Green's function is then derived. A second approximation, which takes certain two-particle correlations into account, is shown to produce various additional effects: The interaction between particles is altered in a manner characterized by the intensive macroscopic parameters, and the modification and spread of the energy-momentum relation come into play. In the final section compact formal expressions for the Green's functions and other physical quantities are derived. Alternative equations and systematic approximations for the Green's functions are obtained.

Paul C. Martin and Julian Schwinger

1959-09-15T23:59:59.000Z

436

Plasma jets and plasma bullets  

Science Journals Connector (OSTI)

Plasma plumes, or plasma jets, belong to a large family of gas discharges whereby the discharge plasma is extended beyond the plasma generation region into the surrounding ambience, either by a field (e.g. electromagnetic, convective gas flow, or shock wave) or a gradient of a directionless physical quantity (e.g. particle density, pressure, or temperature). This physical extension of a plasma plume gives rise to a strong interaction with its surrounding environment, and the interaction alters the properties of both the plasma and the environment, often in a nonlinear and dynamic fashion. The plasma is therefore not confined by defined physical walls, thus extending opportunities for material treatment applications as well as bringing in new challenges in science and technology associated with complex open-boundary problems. Some of the most common examples may be found in dense plasmas with very high dissipation of externally supplied energy (e.g. in electrical, optical or thermal forms) and often in or close to thermal equilibrium. For these dense plasmas, their characteristics are determined predominantly by strong physical forces of different fields, such as electrical, magnetic, thermal, shock wave, and their nonlinear interactions [1]. Common to these dense plasma plumes are significant macroscopic plasma movement and considerable decomposition of solid materials (e.g. vaporization). Their applications are numerous and include detection of elemental traces, synthesis of high-temperature materials and welding, laser--plasma interactions, and relativistic jets in particle accelerators and in space [2]–[4]. Scientific challenges in the understanding of plasma jets are exciting and multidisciplinary, involving interweaving transitions of all four states of matter, and their technological applications are wide-ranging and growing rapidly. Using the Web of Science database, a search for journal papers on non-fusion plasma jets reveals that a long initial phase up to 1990 with only 31 papers per year on average, and a total of some 1300 papers, precedes a considerable growth of some 35–50% in research activity every five years, over the last 20 years or so. As shown in the table, the annual dissemination of the field is more than 1600 papers and the total number of papers is in excess of 20000. This upwards trajectory is typical of a strong and growing subject area in physical science, with considerable capacity in both fundamental science and applications. PeriodNumber of papersPapers per annum 1948–1990130031 1991–19952279456 1996–20003447689 2001–20054571914 2006–201066401328 2011 1658 In many of the dense plasma jets discussed above, strong physical forces generated by the plasma are often desired and this favours plasma generation at elevated gas pressure, including atmospheric pressure, which favours a high level of gas ionization. Historically it has been challenging to reduce and control the strong physical forces in high-pressure plasmas for applications where these are unwanted, for example, surface modification of polymeric sheets [5]. Indeed, there is a real need for a vast range of material processing applications at temperatures below 100oC (or below 400 K) and this favours atmospheric-pressure plasma jets sustained far from thermal equilibrium with the dissipated electrical energy largely used not in heat generation but in unleashing non-equilibrium chemical reactions. The long-standing difficulty of effectively controlling the level of gas ionization at atmospheric pressure was overcome by the technological breakthrough of achieving atmospheric-pressure glow discharges in the late 1980s [6]. A related challenge stemming from high collisionality of atmospheric-pressure plasmas (v >> ?0) means that large-area plasmas sustained between parallel-plate electrodes are very susceptible to strong plasma instabilities when molecular gases are introduced for processing applications. This led to an effective technological solution in the early to late 1990s of confining atmospheric plasmas in a small v

M G Kong; B N Ganguly; R F Hicks

2012-01-01T23:59:59.000Z

437

Summary on the depressurization from supercritical pressure conditions  

SciTech Connect (OSTI)

When a fluid discharges from a high pressure and temperature system, a 'choking' or critical condition occurs, and the flow rate becomes independent of the downstream pressure. During a postulated loss of coolant accident (LOCA) of a water reactor the break flow will be subject to this condition. An accurate estimation of the critical flow rate is important for the evaluation of the reactor safety, because this flow rate controls the loss of coolant inventory and energy from the system, and thus has a significant effect on the accident consequences[1]. In the design of safety systems for a super critical water reactor (SCWR), postulated LOCA transients are particularly important due to the lower coolant inventory compared to a typical PWR for the same power output. This lower coolant inventory would result in a faster transient response of the SCWR, and hence accurate prediction of the critical discharge is mandatory. Under potential two-phase conditions critical flow is dominated by the vapor content or quality of the vapor, which is closely related with the onset of vaporization and the interfacial interaction between phases [2]. This presents a major challenge for the estimation of the flow rate due to the lack of the knowledge of those processes, especially under the conditions of interest for the SCWR. According to the limited data of supercritical fluids, the critical flows at conditions above the pseudo-critical point seem to be fairly stable and consistent with the subcritical homogeneous equilibrium model (HEM) model predictions, while having a lower flow rate than those in the two-phase region. Thus the major difficulty in the prediction of the depressurization flow rates remains in the region where two phases co-exist at the top of the vapor dome. In this region, the flow rate is strongly affected by the nozzle geometry and tends to be unstable. Various models for this region have been developed with different assumptions, e.g. the HEM and Moody model [3], and the Henry-Fauske non-equilibrium model [4], and are currently used in subcritical pressure reactor safety design[5]. It appears that some of these models could be reasonably extended to above the thermodynamic pseudo-critical point. The more stable and lower discharge flow rates observed in conditions above the pseudo-critical point suggests that even though SCWR's have a smaller coolant inventory, the safety implications of a LOCA and the subsequent depressurization may not be as severe as expected, this however needs to be confirmed by a rigorous evaluation of the particular event and further evaluation of the critical flow rate. This paper will summarize activities on critical flow models, experimental data and numerical modeling during blowdown from supercritical pressure conditions under the International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) on 'Heat Transfer Behaviour and Thermo-hydraulics Code testing for SCWRs'. (authors)

Anderson, M. [Univ. of Wisconsin Madison, 1500 Engineering Dr., Madison, WI 53706 (United States); Chen, Y. [Dept. of Reactor Engineering, Research and Design, Reactor Thermal-Hydraulic Lab., China Inst. of Atomic Energy, P.O.Box 275 59, 102413 Beijing (China); Ammirable, L. [JRC/Inst. for Energy and Transport (Netherlands); Novog, D. [Dept. of Engineering Physics, McMaster Univ., 1280 Main Street, ON (Canada); Yamada, K. [International Atomic Energy Agency, Vienna International Centre, P.O. Box 100, 1400 Vienna (Austria)

2012-07-01T23:59:59.000Z

438

Optical emission spectroscopic diagnostics of a non-thermal atmospheric pressure helium-oxygen plasma jet for biomedical applications  

Science Journals Connector (OSTI)

In this work we have applied optical emission spectroscopy diagnostics to investigate the characteristics of a non-thermal atmospheric pressure helium plasma jet. The discharge characteristics in the active and afterglow region of the plasma jet that are critical for biomedical applications have been investigated. The voltage-current characteristics of the plasma discharge were analyzed and the average plasma power was measured to be around 18?W. The effect of addition of small fractions of oxygen at 0.1%–0.5% on the plasma jet characteristics was studied. The addition of oxygen resulted in a decrease in plasma plume length due to the electronegativity property of oxygen. Atomic and molecular lines of selected reactive plasma species that are considered to be useful to induce biochemical reactions such as OH transitions A 2 ? + ( ? = 0 1 ) ? X 2 ? ( ? ? = 0 ) at 308?nm and A 2 ? + ( ? = 0 1 ) ? X 2 ? ( ? ? = 1 ) at 287?nm O I transitions 3p5P?3s5S0 at 777.41?nm and 3p3P?3s3S0 at 844.6?nm N2(C-B) second positive system with electronic transition C 3 ? u ? ? B 3 ? g ? in the range of 300–450?nm and N2 +(B-X) first negative system with electronic transition B 2 ? u + ? X 2 ? g + ( ? ? = 0 ) at 391.4?nm have been studied. The atomic emission lines of helium were identified including the He I transitions 3p3P0?2s3S at 388.8?nm 3p1P0? 2s1S at 501.6?nm 3d3D?2p3P0 at 587.6?nm 3d1D?2p1P0 at 667.8?nm 3s3S1?2p3P0 at 706.5?nm 3s1S0?2p1P0 at 728.1?nm and H? transition 2p-3d at 656.3?nm. Using a spectral fitting method the OH radicals at 306–312?nm the rotational and vibrational temperatures equivalent to gas temperatures of the discharge was measured and the effective non-equilibrium nature of the plasma jet was demonstrated. Our results show that in the entire active plasma region the gas temperature remains at 310?±?25?K and 340?±?25?K and it increases to 320?±?25?K and 360?±?25?K in the afterglow region of the plasma jet for pure helium and helium/oxygen (0.1%) mixture respectively. Additionally the vibrational temperatures range from 2200?±?100?K and 2500?±?100?K for pure helium and helium/oxygen (0.1%) mixture respectively. The plasma jet was tested on heat sensitive polymer films used in biomedical applications such as polyethylene terephthalate and poly-L-lactide samples continuously for several minutes without causing any physical or thermal damage to the films. The plasma jet produces significant reactive species of interest while the gas temperatures remain very low demonstrating its potential for a range of biomedical applications.

2013-01-01T23:59:59.000Z

439

Atmospheric-pressure plasma cleaning of contaminated surfaces. 1998 annual progress report  

SciTech Connect (OSTI)

'The object of this research program is to develop an atmospheric-pressure plasma jet for converting transuranic wastes (TRUs) into low-level radioactive wastes (LLWs). This plasma process will be used to efficiently decontaminate a wide range of structures and equipment. This report summarizes work after 1 year and 9 months of a 3-year project. A picture of the atmospheric-pressure plasma jet is shown in Fig. 1. This new plasma source consists of two concentric electrodes through which a mixture of helium and reactive gases flow. The plasma is ignited by applying 13.56 MHz RF power to the inner electrode. The characteristics of this discharge are different from other atmospheric-pressure plasmas, such as transferred arcs, torches, coronas and silent discharges. Shown in Fig. 2 is the current-voltage curve for the plasma jet. Spark breakdown occurs at 0.01 A, and is proceeded by a normal glow region, in which the voltage remains constant with increasing current, and an abnormal glow region, in which the voltage increases rapidly with current. At about 1.0 A and 225 V, the plasma begins to arc. The normal glow region is rarely observed in atmospheric pressure plasmas. They usually proceed directly from spark breakdown to arcing. The trend shown in the figure indicates that the plasma jet is stable over a wide range of operating conditions. The distribution of reactive species in a plasma jet, containing oxygen and helium, has been characterized by Langmuir probe measurements, optical emission spectroscopy, and ultraviolet absorption spectroscopy. The charged particle density ranges from about 5 x 10{sup 11} cm{sup -3} inside the plasma to 1 x 10{sup 10} cm{sup -3} in the jet exit. The concentration of metastable oxygen molecules (a 1 Dg and b 1 Sg{sup +} ) is estimated to be between 10{sup 12} to 10{sup 13} cm{sup -3} . By contrast, the ozone concentration increases from about 5 x 10{sup 14} cm{sup -3} inside the plasma to 1 x 10{sup 16} cm{sup -3} in the effluent. The ozone molecules are produced by the reaction of O atoms with O{sub 2} molecules: O + O{sub 2} + M a O{sub 3} + M. To generate the amount of ozone observed, the O atom concentration in the plasma must be near 1 x 10{sup 16} cm{sup -3}, or about 10% of the oxygen fed. These results are quite unexpected, because most non-equilibrium, low-temperature plasmas achieve a much lower degree of dissociation. The etching of actinide metals has been simulated by using tantalum as a surrogate material. Tantalum etching rates of up to 1.2 mm/min are achieved with the plasma jet using a CF{sub 4}/O{sub 2}/He gas feed. This is 10 times faster than conventional plasma systems, and indicates that the atmospheric-pressure plasma is a promising technology for decontamination of DOE sites. Finally, the plasma jet has been successfully modified to process larger areas, up to about 1.0 ft{sup 2} . Work is underway to increase the process scale further. The authors are confident that this technology is capable of being adapted for decontamination operations in the field.'

Hicks, R.F. [Univ. of California, Los Angeles, CA (US); Selwyn, G. [Los Alamos National Lab., NM (US)

1998-06-01T23:59:59.000Z

440

PHENIX EXPERIMENT AT RHIC: DECADAL PLAN 2004-2013  

SciTech Connect (OSTI)

The PHENIX Collaboration has developed a plan for the detailed investigation of quantum chromodynamics in the next decade. The demonstrated capabilities of the PHENIX experiment to measure rare processes in hadronic, leptonic and photonic channels, in combination with RHIC's unparalleled flexibility as a hadronic collider, provides a physics program of extraordinary breadth and depth. A superlative set of measurements to elucidate the states of both hot and cold nuclear matter, and to measure the spin structure of the proton has been identified. The components of this plan include: (1) Definitive measurements that will establish the nature of the matter created in nucleus+nucleus collisions, that will determine if the description of such matter as a quark-gluon plasma is appropriate, and that will quantify both the equilibrium and non-equilibrium features of the produced medium. (2) Precision measurements of the gluon structure of the proton, and of the spin structure of the gluon and sea-quark distributions of the proton via polarized proton+proton collisions. (3) Determination of the gluon distribution in cold nuclear matter using proton+nucleus collisions. Each of these fundamental fields of investigation will be addressed through a program of correlated measurements in some or all of the following channels: (1) Particle production at high transverse momentum, studied via single particle inclusive measurements of identified charged and neutral hadrons, multi-particle correlations and jet production. (2) Direct photon, photon+jet and virtual photon production. (3) Light and heavy vector mesons. (4) Heavy flavor production. These measurements, together with the established PHENIX abilities to identify hadrons at low transverse momentum, to perform detailed centrality selections, and to monitor polarization and luminosity with high precision create a superb opportunity for performing world-class science with PHENIX for the next decade. A portion of this program is achievable using the present capabilities of PHENIX experimental apparatus, but the physics reach is considerably extended and the program made even more compelling by a proposed set of upgrades which include: (1) An aerogel and time-of-flight system to provide complete {pi}/K/p separation for momenta up to 10 GeV/c. (2) A vertex detector to detect displaced vertices from the decay of mesons containing charm or bottom quarks. (3) A hadron-blind detector to detect and track electrons near the vertex. (4) A micro-TPC to extend the range of PHENIX tracking in azimuth and pseudo-rapidity. (5) A forward detector upgrade for an improved muon trigger to preserve sensitivity at the highest projected RHIC luminosities. (6) A forward calorimeter to provide photon+jet studies over a wide kinematic range. The success of the proposed program is contingent upon several factors external to PHENIX. Implementation of the upgrades is predicated on the availability of R&D funds to develop the required detector technologies on a timely, and in some cases urgent, basis. The necessity for such funding, and the physics merit of the proposed PHENIX program, has been endorsed in the first meeting of BNL's Detector Advisory Committee in December, 2002. Progress towards the physics goals depends in an essential way on the development of the design values for RHIC luminosity, polarization and availability. An analysis based on the guidance from the Collider Accelerator Department indicates that moderate increases in the yearly running time lead to very considerable increases in progress toward the enunciated goals. Efficient access to the rarest probes in the proposed program is achieved via the order-of-magnitude increase in luminosity provided by RHIC-II.

ZAJC,W.ET. AL.

2003-11-30T23:59:59.000Z

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441

EXPLORING THE ORIGIN AND FATE OF THE MAGELLANIC STREAM WITH ULTRAVIOLET AND OPTICAL ABSORPTION  

SciTech Connect (OSTI)

We present an analysis of ionization and metal enrichment in the Magellanic Stream (MS), the nearest gaseous tidal stream, using Hubble Space Telescope/STIS and FUSE ultraviolet spectroscopy of two background active galactic nuclei. The targets are NGC 7469, lying directly behind the MS with log N(H I){sub MS} = 18.63 {+-} 0.03(stat) {+-} 0.08(syst), and Mrk 335, lying 24.{sup 0}7 away with log N(H I){sub MS} = 16.67 {+-} 0.05. For NGC 7469, we include optical spectroscopy from VLT/UVES. In both sight lines, the MS is detected in low-ion (O I, C II, C III, Si II, Si III, Al II, Ca II) and high-ion (O VI, C IV, Si IV) absorption. Toward NGC 7469, we measure an MS oxygen abundance [O/H]{sub MS} = [O I/H I] = -1.00 {+-} 0.05(stat) {+-} 0.08(syst), supporting the view that the Stream originates in the Small Magellanic Cloud rather than the Large Magellanic Cloud. We use CLOUDY to model the low-ion phase of the Stream as a photoionized plasma using the observed Si III/Si II and C III/C II ratios. Toward Mrk 335, this yields an ionization parameter between log U = -3.45 and -3.15, a gas density log (n {sub H}/cm{sup -3}) between -2.51 and -2.21, and a hydrogen ionization fraction of 98.9%-99.5%. Toward NGC 7469, we derive sub-solar abundance ratios for [Si/O], [Fe/O], and [Al/O], indicating the presence of dust in the MS. The high-ion column densities are too large to be explained by photoionization, but also cannot be explained by a single-temperature collisional ionization model (equilibrium or non-equilibrium). This suggests that the high-ion plasma is multi-phase, with an Si IV region, a hotter O VI region, and C IV potentially contributing to each. Summing over the low-ion and high-ion phases, we derive conservative lower limits on the ratio N(total H II)/N(H I) of {approx}>19 toward NGC 7469 and {approx}>330 toward Mrk 335, showing that along these two directions the vast majority of the Stream has been ionized. The presence of warm-hot plasma together with the small-scale structure observed at 21 cm provides evidence for an evaporative interaction with the hot Galactic corona. This scenario, predicted by hydrodynamical simulations, suggests that the fate of the MS will be to replenish the Galactic corona with new plasma, rather than to bring neutral fuel to the disk.

Fox, Andrew J.; Smoker, Jonathan V. [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Wakker, Bart P.; Savage, Blair D. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter St., Madison, WI 53706 (United States); Richter, Philipp [Institut fuer Physik und Astronomie, Universitaet Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, 14476, Potsdam (Germany); Sembach, Kenneth R., E-mail: afox@eso.or [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

2010-08-01T23:59:59.000Z

442

Amorphous and nanocrystalline phase formation in highly-driven Al-based binary alloys  

SciTech Connect (OSTI)

Remarkable advances have been made since rapid solidification was first introduced to the field of materials science and technology. New types of materials such as amorphous alloys and nanostructure materials have been developed as a result of rapid solidification techniques. While these advances are, in many respects, ground breaking, much remains to be discerned concerning the fundamental relationships that exist between a liquid and a rapidly solidified solid. The scope of the current dissertation involves an extensive set of experimental, analytical, and computational studies designed to increase the overall understanding of morphological selection, phase competition, and structural hierarchy that occurs under far-from equilibrium conditions. High pressure gas atomization and Cu-block melt-spinning are the two different rapid solidification techniques applied in this study. The research is mainly focused on Al-Si and Al-Sm alloy systems. Silicon and samarium produce different, yet favorable, systems for exploration when alloyed with aluminum under far-from equilibrium conditions. One of the main differences comes from the positions of their respective T{sub 0} curves, which makes Al-Si a good candidate for solubility extension while the plunging T{sub 0} line in Al-Sm promotes glass formation. The rapidly solidified gas-atomized Al-Si powders within a composition range of 15 to 50 wt% Si are examined using scanning and transmission electron microscopy. The non-equilibrium partitioning and morphological selection observed by examining powders at different size classes are described via a microstructure map. The interface velocities and the amount of undercooling present in the powders are estimated from measured eutectic spacings based on Jackson-Hunt (JH) and Trivedi-Magnin-Kurz (TMK) models, which permit a direct comparison of theoretical predictions. For an average particle size of 10 {micro}m with a Peclet number of {approx}0.2, JH and TMK deviate from each other. This deviation indicates an adiabatic type solidification path where heat of fusion is reabsorbed. It is interesting that this particle size range is also consistent with the appearance of a microcellular growth. While no glass formation is observed within this system, the smallest size powders appear to consist of a mixture of nanocrystalline Si and Al. Al-Sm alloys have been investigated within a composition range of 34 to 42 wt% Sm. Gas atomized powders of Al-Sm are investigated to explore the morphological and structural hierarchy that correlates with different degrees of departure from full equilibrium conditions. The resultant powders show a variety of structural selection with respect to amount of undercooling, with an amorphous structure appearing at the highest cooling rates. Because of the chaotic nature of gas atomization, Cu-block melt-spinning is used to produce a homogeneous amorphous structure. The as-quenched structure within Al-34 to 42 wt% Sm consists of nanocrystalline fcc-Al (on the order of 5 nm) embedded in an amorphous matrix. The nucleation density of fcc-Al after initial crystallization is on the order of 10{sup 22}-10{sup 23} m{sup -3}, which is 10{sup 5}-10{sup 6} orders of magnitude higher than what classical nucleation theory predicts. Detailed analysis of liquid and as-quenched structures using high energy synchrotron X-ray diffraction, high energy transmission electron microscopy, and atom probe tomography techniques revealed an Al-Sm network similar in appearance to a medium range order (MRO) structure. A model whereby these MRO clusters promote the observed high nucleation density of fcc-Al nanocrystals is proposed. The devitrification path was identified using high temperature, in-situ, high energy synchrotron X-ray diffraction techniques and the crystallization kinetics were described using an analytical Johnson-Mehl-Avrami (JMA) approach.

Kalay, Yunus Eren

2008-10-15T23:59:59.000Z

443

The influence of Zn vacancy on thermal conductivity of {beta}-Zn{sub 4}Sb{sub 3}: A molecular dynamics study  

SciTech Connect (OSTI)

The influence of Zn vacancy on lattice thermal conductivity of {beta}-Zn{sub 4}Sb{sub 3} is studied by non-equilibrium molecular dynamics approach. The lattice thermal conductivity of single-crystal bulk {beta}-Zn{sub 4}Sb{sub 3} decreases rapidly when there is Zn vacancy, and then when the vacancy grows, the lattice thermal conductivity decreases further but rather slowly, which suggests a scaling law of k{sub v}{approx}n{sub v}{sup -{alpha}} of Zn atom vacancy (n{sub v}) to lattice thermal conductivity (k{sub vac}). This phenomenon is attributed to the fact that the existence of vacancy scattering can significantly decrease the mean free path. When the Zn atom vacant proportion reaches 10%, that is the vacancy model of {beta}-Zn{sub 4}Sb{sub 3}, the lattice thermal conductivity is 1.32 W/mk along the x-axis and 1.62 W/mk along the z-axis, respectively, which drops by {approx}90% that of its full occupancy model. Therefore, our calculations show that the 10% Zn atom vacancy in {beta}-Zn{sub 4}Sb{sub 3} is the main reason for its exceptionally low thermal conductivity, and the interstitial Zn atoms have little effect on the thermal conductivity of single-crystal {beta}-Zn{sub 4}Sb{sub 3}. - Graphical abstract: The bulk thermal conductivity (k{sub pure}) is 11.88 W/mk along the x-axis and 20.00 W/mk the z-axis. When it is 10% vacancy, namely the vacancy model of {beta}-Zn{sub 4}Sb{sub 3}, the thermal conductivity of {beta}-Zn{sub 4}Sb{sub 3} is 1.32 W/mk along the x-axis and 1.62 W/mk along the z-axis, respectively, which reduces by {approx}90% that of its full occupancy model. Our calculations show that the 10% Zn atom vacancy in the crystal structure of {beta}-Zn{sub 4}Sb{sub 3} is the main reason for its exceptionally low thermal conductivity, and the interstitial Zn atoms have little effect on the thermal conductivity of single-crystal {beta}-Zn{sub 4}Sb{sub 3}. Highlights: Black-Right-Pointing-Pointer The lattice stability of {beta}-Zn{sub 4}Sb{sub 3} decreases remarkably with the growing vacancy. Black-Right-Pointing-Pointer 10% Zn vacancy leads to its low thermal conductivity and structural instability. Black-Right-Pointing-Pointer Interstitial Zn atoms in {beta}-Zn{sub 4}Sb{sub 3} mainly stabilize the crystal structure.

Zhai, Pengcheng [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China) [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Li, Guodong; Wen, Pengfei [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)] [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Li, Yao, E-mail: liyao06@126.com [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)] [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Qingjie; Liu, Lisheng [State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)] [State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2012-09-15T23:59:59.000Z

444

Oxygen Transport Membranes  

SciTech Connect (OSTI)

The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the small polaron conduction mechanism. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were used to develop strategies to detect and characterize vacancy creation, dopant segregations and defect association in the oxygen conducting membrane material. The pO{sub 2} and temperature dependence of the conductivity, non-stoichiometry and thermal-expansion behavior of compositions with increasing complexity of substitution on the perovskite A and B sites were studied. Studies with the perovskite structure show anomalous behavior at low oxygen partial pressures (<10{sup -5} atm). The anomalies are due to non-equilibrium effects and can be avoided by using very strict criteria for the attainment of equilibrium. The slowness of the oxygen equilibration kinetics arises from two different mechanisms. In the first, a two phase region occurs between an oxygen vacancy ordered phase such as brownmillerite SrFeO{sub 2.5} and perovskite SrFeO{sub 3-x}. The slow kinetics is associated with crossing the two phase region. The width of the miscibility gap decreases with increasing temperature and consequently the effect is less pronounced at higher temperature. The preferred kinetic pathway to reduction of perovskite ferrites when the vacancy concentration corresponds to the formation of significant concentrations of Fe{sup 2+} is via the formation of a Ruddlesden-Popper (RP) phases as clearly observed in the case of La{sub 0.5}Sr{sub 0.5}FeO{sub 3-x} where LaSrFeO{sub 4} is found together with Fe. In more complex compositions, such as LSFTO, iron or iron rich phases are observed locally with no evidence for the presence of discrete RP phase. Fracture strength of tubular perovskite membranes was determined in air and in reducing atmospheric conditions. The strength of the membrane decreased with temperature and severity of reducing conditions although the strength distribution (Weibull parameter, m) was relatively unaltered. Surface and volume dominated the fracture origins and the overall fracture was purely transgranular. The dual phas

S. Bandopadhyay

2008-08-30T23:59:59.000Z