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Sample records for tailored gc5 non-equilibrium

  1. Non-equilibrium STLS approach to transport properties of single...

    Office of Scientific and Technical Information (OSTI)

    Non-equilibrium STLS approach to transport properties of single impurity Anderson model Citation Details In-Document Search Title: Non-equilibrium STLS approach to transport ...

  2. Non-equilibrium many body dynamics

    SciTech Connect

    Creutz, M.; Gyulassy, M.

    1997-09-22

    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.

  3. Fe Atomic Data for Non-equilibrium Ionization Plasmas Eriksen...

    Office of Scientific and Technical Information (OSTI)

    Fe Atomic Data for Non-equilibrium Ionization Plasmas Eriksen, Kristoffer A. Los Alamos National Laboratory; Fontes, Christopher J. Los Alamos National Laboratory; Colgan,...

  4. Non-equilibrium tunneling in zigzag graphene nanoribbon break...

    Office of Scientific and Technical Information (OSTI)

    Spintronic devices promise new faster and lower energy-consumption electronic systems. ... In this paper, by utilizing density functional theory and non-equilibrium green function ...

  5. Electron Broadening of Isolated Lines with Stationary Non-Equilibrium...

    Office of Scientific and Technical Information (OSTI)

    Title: Electron Broadening of Isolated Lines with Stationary Non-Equilibrium Level Populations It is shown that a quantum kinetic theory approach to line broadening, extended to ...

  6. Fe Atomic Data for Non-equilibrium Ionization Plasmas (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Fe Atomic Data for Non-equilibrium Ionization Plasmas Citation Details In-Document Search Title: Fe Atomic Data for Non-equilibrium Ionization Plasmas No abstract prepared. Authors: Eriksen, Kristoffer A. [1] ; Fontes, Christopher J. [1] ; Colgan, James P. [1] ; Zhang, Honglin [1] ; Hungerford, Aimee L. [1] ; Fryer, Christopher L. [1] ; Hughes, John P. [2] ; Smith, Randall K. [3] ; Badenes, Carles [4] + Show Author Affiliations Los Alamos National Laboratory Rutgers

  7. Boltzmann equation solver adapted to emergent chemical non-equilibrium

    SciTech Connect

    Birrell, Jeremiah; Wilkening, Jon; Rafelski, Johann

    2015-01-15

    We present a novel method to solve the spatially homogeneous and isotropic relativistic Boltzmann equation. We employ a basis set of orthogonal polynomials dynamically adapted to allow for emergence of chemical non-equilibrium. Two time dependent parameters characterize the set of orthogonal polynomials, the effective temperature T(t) and phase space occupation factor ?(t). In this first paper we address (effectively) massless fermions and derive dynamical equations for T(t) and ?(t) such that the zeroth order term of the basis alone captures the particle number density and energy density of each particle distribution. We validate our method and illustrate the reduced computational cost and the ability to easily represent final state chemical non-equilibrium by studying a model problem that is motivated by the physics of the neutrino freeze-out processes in the early Universe, where the essential physical characteristics include reheating from another disappearing particle component (e{sup }-annihilation)

  8. Non-Equilibrium Pathways during Electrochemical Phase Transformations in

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Single Crystals Revealed by Dynamic Chemical Imaging at Nanoscale Resolution | Stanford Synchrotron Radiation Lightsource Non-Equilibrium Pathways during Electrochemical Phase Transformations in Single Crystals Revealed by Dynamic Chemical Imaging at Nanoscale Resolution Friday, February 27, 2015 The energy density of current batteries is limited by the practical capacity of the positive electrode, which is the determined by the properties of the active material and its concentration in the

  9. Characterization of non equilibrium effects on high quality critical flows

    SciTech Connect

    Camelo, E.; Lemonnier, H.; Ochterbeck, J.

    1995-09-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness.

  10. High-Z Non-Equilibrium Physics and Bright X-ray Sources with...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser Targets Citation Details In-Document Search Title: High-Z Non-Equilibrium Physics and ...

  11. HeteroFoaM | U.S. DOE Office of Science (SC)

    Office of Science (SC)

    Grand Challenges Addressed GC2 Tailored GC3 Emergent GC5 Non-equilibrium BRN Addressed Advanced Nuclear Energy Systems Electrical Energy Storage Materials under Extreme ...

  12. High-Z Non-Equilibrium Physics and Bright X-ray Sources with...

    Office of Scientific and Technical Information (OSTI)

    X-ray Sources with New Laser Targets Citation Details In-Document Search Title: High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser Targets You are ...

  13. Non-equilibrium scaling analysis of the Kondo model with voltage bias

    SciTech Connect

    Fritsch, Peter Kehrein, Stefan

    2009-05-15

    The quintessential description of Kondo physics in equilibrium is obtained within a scaling picture that shows the buildup of Kondo screening at low temperature. For the non-equilibrium Kondo model with a voltage bias, the key new feature are decoherence effects due to the current across the impurity. In the present paper, we show how one can develop a consistent framework for studying the non-equilibrium Kondo model within a scaling picture of infinitesimal unitary transformations (flow equations). Decoherence effects appear naturally in third order of the {beta}-function and dominate the Hamiltonian flow for sufficiently large voltage bias. We work out the spin dynamics in non-equilibrium and compare it with finite temperature equilibrium results. In particular, we report on the behavior of the static spin susceptibility including leading logarithmic corrections and compare it with the celebrated equilibrium result as a function of temperature.

  14. Non-equilibrium STLS approach to transport properties of single impurity Anderson model

    SciTech Connect

    Rezai, Raheleh Ebrahimi, Farshad

    2014-04-15

    In this work, using the non-equilibrium Keldysh formalism, we study the effects of the electron–electron interaction and the electron-spin correlation on the non-equilibrium Kondo effect and the transport properties of the symmetric single impurity Anderson model (SIAM) at zero temperature by generalizing the self-consistent method of Singwi, Tosi, Land, and Sjolander (STLS) for a single-band tight-binding model with Hubbard type interaction to out of equilibrium steady-states. We at first determine in a self-consistent manner the non-equilibrium spin correlation function, the effective Hubbard interaction, and the double-occupancy at the impurity site. Then, using the non-equilibrium STLS spin polarization function in the non-equilibrium formalism of the iterative perturbation theory (IPT) of Yosida and Yamada, and Horvatic and Zlatic, we compute the spectral density, the current–voltage characteristics and the differential conductance as functions of the applied bias and the strength of on-site Hubbard interaction. We compare our spectral densities at zero bias with the results of numerical renormalization group (NRG) and depict the effects of the electron–electron interaction and electron-spin correlation at the impurity site on the aforementioned properties by comparing our numerical result with the order U{sup 2} IPT. Finally, we show that the obtained numerical results on the differential conductance have a quadratic universal scaling behavior and the resulting Kondo temperature shows an exponential behavior. -- Highlights: •We introduce for the first time the non-equilibrium method of STLS for Hubbard type models. •We determine the transport properties of SIAM using the non-equilibrium STLS method. •We compare our results with order-U2 IPT and NRG. •We show that non-equilibrium STLS, contrary to the GW and self-consistent RPA, produces the two Hubbard peaks in DOS. •We show that the method keeps the universal scaling behavior and correct

  15. Prediction of non-equilibrium solidification modes in austenitic stainless steel laser welds

    SciTech Connect

    Vitek, J.M.; David, S.A.

    1993-08-01

    A primary austenitic, non-equilibrium mode of solidification can be induced in many 300 series austenitic stainless steels by laser welding and other rapid solidification techniques. The change in solidification mode can often result in a fully austenitic microstructure compared to the two phase ferrite plus austenite microstructure that is commonly found after primary ferrite solidification. A predictive capability for the solidification mode under rapid solidification conditions such as laser welding is needed since the microstructure and properties are closely related to solidification behavior. Conventional constitutional diagrams do not predict with any reliability the change to non-equilibrium austenitic solidification mode. Several means that have been attempted to predict the solidification behavior under extreme conditions are reviewed. The Cr{sub EQ}/Ni{sub EQ} ratio is shown to be unreliable, at least with the equivalence factors commonly used. Theoretical calculations of growth rate competition between ferrite and austenite solidification show promise, but some ambiguity results from inaccuracy in thermophysical material parameters. Use of calculated thermodynamic parameters such as equilibrium and non-equilibrium liquidus and solidus temperatures also shows some promise. However, this approach is not completely satisfactory and reliable either. It is concluded that a reliable and accurate method for predicting the tendency of austenitic stainless steels to solidify in the non-equilibrium mode is not yet available.

  16. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation

    DOE PAGES [OSTI]

    Ma, Wen; Senanayake, Sanjaya D.; Herbert, F. William; Yildiz, Bilge

    2015-03-11

    The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr1+, Zr2+, and Zr3+ as non-equilibrium oxidation states, in addition to Zr4+ in the stoichiometric ZrO2. This finding resolves the long-debated question of whether it is possible to form any valence states between Zr0 and Zr4+ at the metal-oxide interface. As a result, the presence of local strong electric fields andmore » the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr.« less

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

    SciTech Connect

    Choi, Jeong

    2011-08-15

    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

  18. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation

    SciTech Connect

    Ma, Wen; Senanayake, Sanjaya D.; Herbert, F. William; Yildiz, Bilge

    2015-03-11

    The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr1+, Zr2+, and Zr3+ as non-equilibrium oxidation states, in addition to Zr4+ in the stoichiometric ZrO2. This finding resolves the long-debated question of whether it is possible to form any valence states between Zr0 and Zr4+ at the metal-oxide interface. As a result, the presence of local strong electric fields and the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr.

  19. Laser induced plasma on copper target, a non-equilibrium model

    SciTech Connect

    Oumeziane, Amina Ait Liani, Bachir; Parisse, Jean-Denis

    2014-02-15

    The aim of this work is to present a comprehensive numerical model for the UV laser ablation of metal targets, it focuses mainly on the prediction of laser induced plasma thresholds, the effect of the laser-plasma interaction, and the importance of the electronic non-equilibrium in the laser induced plume and its expansion in the background gas. This paper describes a set of numerical models for laser-matter interaction between 193-248 and 355 nm lasers and a copper target. Along with the thermal effects inside the material resulting from the irradiation of the latter with the pulsed laser, the laser-evaporated matter interaction and the plasma formation are thoroughly modelled. In the laser induced plume, the electronic nonequilibrium and the laser beam absorption have been investigated. Our calculations of the plasmas ignition thresholds on copper targets have been validated and compared to experimental as well as theoretical results. Comparison with experiment data indicates that our results are in good agreement with those reported in the literature. Furthermore, the inclusion of electronic non-equilibrium in our work indicated that this important process must be included in models of laser ablation and plasma plume formation.

  20. Potential and flux field landscape theory. II. Non-equilibrium thermodynamics of spatially inhomogeneous stochastic dynamical systems

    SciTech Connect

    Wu, Wei; Wang, Jin

    2014-09-14

    We have established a general non-equilibrium thermodynamic formalism consistently applicable to both spatially homogeneous and, more importantly, spatially inhomogeneous systems, governed by the Langevin and Fokker-Planck stochastic dynamics with multiple state transition mechanisms, using the potential-flux landscape framework as a bridge connecting stochastic dynamics with non-equilibrium thermodynamics. A set of non-equilibrium thermodynamic equations, quantifying the relations of the non-equilibrium entropy, entropy flow, entropy production, and other thermodynamic quantities, together with their specific expressions, is constructed from a set of dynamical decomposition equations associated with the potential-flux landscape framework. The flux velocity plays a pivotal role on both the dynamic and thermodynamic levels. On the dynamic level, it represents a dynamic force breaking detailed balance, entailing the dynamical decomposition equations. On the thermodynamic level, it represents a thermodynamic force generating entropy production, manifested in the non-equilibrium thermodynamic equations. The Ornstein-Uhlenbeck process and more specific examples, the spatial stochastic neuronal model, in particular, are studied to test and illustrate the general theory. This theoretical framework is particularly suitable to study the non-equilibrium (thermo)dynamics of spatially inhomogeneous systems abundant in nature. This paper is the second of a series.

  1. Collision integrals for charged-charged interaction in two-temperature non-equilibrium plasma

    SciTech Connect

    Ghorui, S.; Das, A. K.

    2013-09-15

    Choice of an appropriate form of shielding distance in the estimation of collision integrals under screened coulomb potential for two-temperature non-equilibrium plasma is addressed. Simple expressions for collision integrals for charged-charged interactions are derived. It is shown that while some of the formalisms used earlier completely ignore the presence of ions, the others incorporating it may result in negative collision integrals for the interactions involving particles at higher charged states. The parametric regimes of concern and impact of different formalisms on the computed transport properties are investigated with specific reference to nitrogen plasma. A revised definition of the shielding distance is proposed, which incorporates both electrons and ions, avoids the problem of negative collision integrals in all practical regimes of interest and results in calculated property values in close agreement with experimentally observed results.

  2. Entropy analysis on non-equilibrium two-phase flow models

    SciTech Connect

    Karwat, H.; Ruan, Y.Q.

    1995-09-01

    A method of entropy analysis according to the second law of thermodynamics is proposed for the assessment of a class of practical non-equilibrium two-phase flow models. Entropy conditions are derived directly from a local instantaneous formulation for an arbitrary control volume of a structural two-phase fluid, which are finally expressed in terms of the averaged thermodynamic independent variables and their time derivatives as well as the boundary conditions for the volume. On the basis of a widely used thermal-hydraulic system code it is demonstrated with practical examples that entropy production rates in control volumes can be numerically quantified by using the data from the output data files. Entropy analysis using the proposed method is useful in identifying some potential problems in two-phase flow models and predictions as well as in studying the effects of some free parameters in closure relationships.

  3. Heat Transfer and Fluid Transport of Supercritical CO2 in Enhanced Geothermal System with Local Thermal Non-equilibrium Model

    DOE PAGES [OSTI]

    Zhang, Le; Luo, Feng; Xu, Ruina; Jiang, Peixue; Liu, Huihai

    2014-12-31

    The heat transfer and fluid transport of supercritical CO2 in enhanced geothermal system (EGS) is studied numerically with local thermal non-equilibrium model, which accounts for the temperature difference between solid matrix and fluid components in porous media and uses two energy equations to describe heat transfer in the solid matrix and in the fluid, respectively. As compared with the previous results of our research group, the effect of local thermal non-equilibrium mainly depends on the volumetric heat transfer coefficient ah, which has a significant effect on the production temperature at reservoir outlet and thermal breakthrough time. The uniformity of volumetricmore » heat transfer coefficient ah has little influence on the thermal breakthrough time, but the temperature difference become more obvious with time after thermal breakthrough with this simulation model. The thermal breakthrough time reduces and the effect of local thermal non-equilibrium becomes significant with decreasing ah.« less

  4. emc2 | U.S. DOE Office of Science (SC)

    Office of Science (SC)

    External link Grand Challenges Addressed GC1 Electrons GC2 Tailored GC3 Emergent GC5 Non-equilibrium BRN Addressed Catalysis for Energy Electrical Energy Storage Hydrogen Economy

  5. Numerical solution of 2D wet steam flow with non-equilibrium condensation and real thermodynamics

    SciTech Connect

    Hric, V.; Halama, J.

    2015-03-10

    An approach to modeling of wet steam flow with non-equilibrium condensation phenomenon is presented. The first part of our flow model is homogeneous Euler system of transport equations for mass, momentum and total energy of wet steam (mixture). The additional second part describes liquid phase via non-homogeneous system of transport equations for moments of droplets number distribution function and relies on corrected classical nucleation theory. Moment equations are closed by linearization of droplet growth rate model. All necessary relations for thermodynamic properties of steam are provided by IAPWS set of equations. However, properties of condensate are simply modeled by liquid saturation data. Two real equations of state are implemented. Recently developed CFD formulation for entropy (does not require iteration process) and so-called IAPWS special gas equation for Helmholtz energy (one iteration loop is necessary). Flow model is validated on converging-diverging supersonic nozzle with Barschdorff geometry. Simulations were performed by in-house CFD code based on finite volume method and stiff character of equations was solved by symmetrical time operator splitting. Achieved results satisfactorily agreed with experimental data.

  6. Cosmological QCD phase transition in steady non-equilibrium dissipative Ho?avaLifshitz early universe

    SciTech Connect

    Khodadi, M. Sepangi, H.R.

    2014-07-15

    We study the phase transition from quarkgluon 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 110?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?avaLifshitz cosmology within an effective model of QCD. We consider a flat FriedmannRobertsonWalker universe filled with a non-causal and a causal bulk viscous cosmological fluid respectively and investigate the effects of the running coupling constants of Ho?avaLifshitz gravity, ?, 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 (?)/s . We assume that the bulk viscosity cosmological background fluid obeys the evolution equation of the steady truncated (Eckart) and full version of the IsraelStewart fluid, respectively. -- Highlights: In this paper we have studied quarkhadron phase transition in the early universe in the context of the Ho?avaLifshitz model. We use a flat FRW universe with the bulk viscosity cosmological background fluid obeying the evolution equation of the steady truncated (Eckart) and full version of the IsraelStewart fluid, respectively.

  7. Angularly Adaptive P1-Double P0 Flux-Limited Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems

    SciTech Connect

    Brantley, P S

    2005-12-13

    The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near a non-equilibrium radiation wave front. In addition, the DP{sub 0} approximation should be more accurate in non-equilibrium optically thin regions where the positive and negative angular domains are largely decoupled. We develop an adaptive angular technique that locally uses either the DP{sub 0} or P{sub 1} flux-limited diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for two test problems due to Su and Olson and to Ganapol and Pomraning for which semi-analytic transport solutions exist. These numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation, both without and with flux-limiting, for non-equilibrium grey radiative transfer.

  8. Angularly Adaptive P1 - Double P0 Flux-Limited Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems

    SciTech Connect

    Brantley, P S

    2006-08-08

    The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near a non-equilibrium radiation wave front. In addition, the DP{sub 0} approximation should be more accurate in non-equilibrium optically thin regions where the positive and negative angular domains are largely decoupled. We develop an adaptive angular technique that locally uses either the DP{sub 0} or P{sub 1} flux-limited diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for two test problems due to Su and Olson and to Ganapol and Pomraning for which semi-analytic transport solutions exist. These numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation, both without and with flux-limiting, for non-equilibrium grey radiative transfer.

  9. Angularly Adaptive P1--Double P0 Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems in Planar Geometry

    SciTech Connect

    Brantley, P S

    2005-06-06

    The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. The standard P{sub 1} angular approximation represents the angular dependence of the radiation specific intensity using a linear function in the angular domain -1 {le} {mu} {le} 1. In contrast, the DP{sub 0} angular approximation represents the angular dependence as isotropic in each half angular range -1 {le} {mu} < 0 and 0 < {mu} {le} 1. Neglecting the time derivative of the radiation flux, both the P{sub 1} and DP{sub 0} equations can be written as a single diffusion equation for the radiation energy density. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near the non-equilibrium wave front. We develop an adaptive angular technique that locally uses either the DP{sub 0} or the P{sub 1} diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for a test problem due to Su and Olson for which a semi-analytic transport solution exists. The numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation for non-equilibrium grey radiative transfer.

  10. The dynamics of single protein molecules is non-equilibrium and self-similar over thirteen decades in time

    DOE PAGES [OSTI]

    Hu, Xiaohu; Hong, Liang; Smith, Micholas Dean; Neusius, Thomas; Cheng, Xiaolin; Smith, Jeremy C.

    2015-11-23

    Here, internal motions of proteins are essential to their function. The time dependence of protein structural fluctuations is highly complex, manifesting subdiffusive, non-exponential behavior with effective relaxation times existing over many decades in time, from ps up to ~102s (refs 1-4). Here, using molecular dynamics simulations, we show that, on timescales from 10–12 to 10–5s, motions in single proteins are self-similar, non-equilibrium and exhibit ageing. The characteristic relaxation time for a distance fluctuation, such as inter-domain motion, is observation-time-dependent, increasing in a simple, power-law fashion, arising from the fractal nature of the topology and geometry of the energy landscape explored.more » Diffusion over the energy landscape follows a non-ergodic continuous time random walk. Comparison with single-molecule experiments suggests that the non-equilibrium self-similar dynamical behavior persists up to timescales approaching the in vivo lifespan of individual protein molecules.« less

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

    SciTech Connect

    Chang, Zhengshi; Zhang, Guanjun; Jiang, Nan; Cao, Zexian

    2014-03-14

    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.

  12. Comparative analysis of quantum cascade laser modeling based on density matrices and non-equilibrium Green's functions

    SciTech Connect

    Lindskog, M. Wacker, A.; Wolf, J. M.; Liverini, V.; Faist, J.; Trinite, V.; Maisons, G.; Carras, M.; Aidam, R.; Ostendorf, R.

    2014-09-08

    We study the operation of an 8.5 μm quantum cascade laser based on GaInAs/AlInAs lattice matched to InP using three different simulation models based on density matrix (DM) and non-equilibrium Green's function (NEGF) formulations. The latter advanced scheme serves as a validation for the simpler DM schemes and, at the same time, provides additional insight, such as the temperatures of the sub-band carrier distributions. We find that for the particular quantum cascade laser studied here, the behavior is well described by simple quantum mechanical estimates based on Fermi's golden rule. As a consequence, the DM model, which includes second order currents, agrees well with the NEGF results. Both these simulations are in accordance with previously reported data and a second regrown device.

  13. The non-equilibrium response of a superconductor to pair-breaking radiation measured over a broad frequency band

    SciTech Connect

    Visser, P. J. de; Yates, S. J. C.; Guruswamy, T.; Goldie, D. J.; Withington, S.; Neto, A.; Llombart, N.; Baryshev, A. M.; Klapwijk, T. M.; Baselmans, J. J. A.

    2015-06-22

    We have measured the absorption of terahertz radiation in a BCS superconductor over a broad range of frequencies from 200 GHz to 1.1 THz, using a broadband antenna-lens system and a tantalum microwave resonator. From low frequencies, the response of the resonator rises rapidly to a maximum at the gap edge of the superconductor. From there on, the response drops to half the maximum response at twice the pair-breaking energy. At higher frequencies, the response rises again due to trapping of pair-breaking phonons in the superconductor. In practice, this is a measurement of the frequency dependence of the quasiparticle creation efficiency due to pair-breaking in a superconductor. The efficiency, calculated from the different non-equilibrium quasiparticle distribution functions at each frequency, is in agreement with the measurements.

  14. Heat Transfer and Fluid Transport of Supercritical CO2 in Enhanced Geothermal System with Local Thermal Non-equilibrium Model

    SciTech Connect

    Zhang, Le; Luo, Feng; Xu, Ruina; Jiang, Peixue; Liu, Huihai

    2014-12-31

    The heat transfer and fluid transport of supercritical CO2 in enhanced geothermal system (EGS) is studied numerically with local thermal non-equilibrium model, which accounts for the temperature difference between solid matrix and fluid components in porous media and uses two energy equations to describe heat transfer in the solid matrix and in the fluid, respectively. As compared with the previous results of our research group, the effect of local thermal non-equilibrium mainly depends on the volumetric heat transfer coefficient ah, which has a significant effect on the production temperature at reservoir outlet and thermal breakthrough time. The uniformity of volumetric heat transfer coefficient ah has little influence on the thermal breakthrough time, but the temperature difference become more obvious with time after thermal breakthrough with this simulation model. The thermal breakthrough time reduces and the effect of local thermal non-equilibrium becomes significant with decreasing ah.

  15. Soft-spring wall based non-periodic boundary conditions for non-equilibrium molecular dynamics of dense fluids

    SciTech Connect

    Ghatage, Dhairyashil; Tomar, Gaurav Shukla, Ratnesh K.

    2015-03-28

    Non-equilibrium molecular dynamics (MD) simulations require imposition of non-periodic boundary conditions (NPBCs) that seamlessly account for the effect of the truncated bulk region on the simulated MD region. Standard implementation of specular boundary conditions in such simulations results in spurious density and force fluctuations near the domain boundary and is therefore inappropriate for coupled atomistic-continuum calculations. In this work, we present a novel NPBC model that relies on boundary atoms attached to a simple cubic lattice with soft springs to account for interactions from particles which would have been present in an untruncated full domain treatment. We show that the proposed model suppresses the unphysical fluctuations in the density to less than 1% of the mean while simultaneously eliminating spurious oscillations in both mean and boundary forces. The model allows for an effective coupling of atomistic and continuum solvers as demonstrated through multiscale simulation of boundary driven singular flow in a cavity. The geometric flexibility of the model enables straightforward extension to nonplanar complex domains without any adverse effects on dynamic properties such as the diffusion coefficient.

  16. Discontinuous non-equilibrium phase transition in a threshold Schloegl model for autocatalysis: Generic two-phase coexistence and metastability

    DOE PAGES [OSTI]

    Wang, Chi -Jen; Liu, Da -Jiang; Evans, James W.

    2015-04-28

    Threshold versions of Schloegl’s model on a lattice, which involve autocatalytic creation and spontaneous annihilation of particles, can provide a simple prototype for discontinuous non-equilibrium phase transitions. These models are equivalent to so-called threshold contact processes. A discontinuous transition between populated and vacuum states can occur selecting a threshold of N ≥ 2 for the minimum number, N, of neighboring particles enabling autocatalytic creation at an empty site. Fundamental open questions remain given the lack of a thermodynamic framework for analysis. For a square lattice with N = 2, we show that phase coexistence occurs not at a unique valuemore » but for a finite range of particle annihilation rate (the natural control parameter). This generic two-phase coexistence also persists when perturbing the model to allow spontaneous particle creation. Such behavior contrasts both the Gibbs phase rule for thermodynamic systems and also previous analysis for this model. We find metastability near the transition corresponding to a non-zero effective line tension, also contrasting previously suggested critical behavior. As a result, mean-field type analysis, extended to treat spatially heterogeneous states, further elucidates model behavior.« less

  17. Discontinuous non-equilibrium phase transition in a threshold Schloegl model for autocatalysis: Generic two-phase coexistence and metastability

    SciTech Connect

    Wang, Chi -Jen; Liu, Da -Jiang; Evans, James W.

    2015-04-28

    Threshold versions of Schloegl’s model on a lattice, which involve autocatalytic creation and spontaneous annihilation of particles, can provide a simple prototype for discontinuous non-equilibrium phase transitions. These models are equivalent to so-called threshold contact processes. A discontinuous transition between populated and vacuum states can occur selecting a threshold of N ≥ 2 for the minimum number, N, of neighboring particles enabling autocatalytic creation at an empty site. Fundamental open questions remain given the lack of a thermodynamic framework for analysis. For a square lattice with N = 2, we show that phase coexistence occurs not at a unique value but for a finite range of particle annihilation rate (the natural control parameter). This generic two-phase coexistence also persists when perturbing the model to allow spontaneous particle creation. Such behavior contrasts both the Gibbs phase rule for thermodynamic systems and also previous analysis for this model. We find metastability near the transition corresponding to a non-zero effective line tension, also contrasting previously suggested critical behavior. As a result, mean-field type analysis, extended to treat spatially heterogeneous states, further elucidates model behavior.

  18. Tailored Porous Materials

    SciTech Connect

    BARTON,THOMAS J.; BULL,LUCY M.; KLEMPERER,WALTER G.; LOY,DOUGLAS A.; MCENANEY,BRIAN; MISONO,MAKOTO; MONSON,PETER A.; PEZ,GUIDO; SCHERER,GEORGE W.; VARTULI,JAMES C.; YAGHI,OMAR M.

    1999-11-09

    Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol-gel derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

  19. Stark broadening for diagnostics of the electron density in non-equilibrium plasma utilizing isotope hydrogen alpha lines

    SciTech Connect

    Yang, Lin; Tan, Xiaohua; Wan, Xiang; Chen, Lei; Jin, Dazhi; Qian, Muyang; Li, Gongping

    2014-04-28

    Two Stark broadening parameters including FWHM (full width at half maximum) and FWHA (full width at half area) of isotope hydrogen alpha lines are simultaneously introduced to determine the electron density of a pulsed vacuum arc jet. To estimate the gas temperature, the rotational temperature of the C{sub 2} Swan system is fit to 2500 ± 100 K. A modified Boltzmann-plot method with b{sub i}-factor is introduced to determine the modified electron temperature. The comparison between results of atomic and ionic lines indicates the jet is in partial local thermodynamic equilibrium and the electron temperature is close to 13 000 ± 400 K. Based on the computational results of Gig-Card calculation, a simple and precise interpolation algorithm for the discrete-points tables can be constructed to obtain the traditional n{sub e}-T{sub e} diagnostic maps of two Stark broadening parameters. The results from FWHA formula by the direct use of FWHM = FWHA and these from the diagnostic map are different. It can be attributed to the imprecise FWHA formula form and the deviation between FWHM and FWHA. The variation of the reduced mass pair due to the non-equilibrium effect contributes to the difference of the results derived from two hydrogen isotope alpha lines. Based on the Stark broadening analysis in this work, a corrected method is set up to determine n{sub e} of (1.10 ± 0.08) × 10{sup 21} m{sup −3}, the reference reduced mass μ{sub 0} pair of (3.30 ± 0.82 and 1.65 ± 0.41), and the ion kinetic temperature of 7900 ± 1800 K.

  20. THE ABUNDANCE OF MOLECULAR HYDROGEN AND ITS CORRELATION WITH MIDPLANE PRESSURE IN GALAXIES: NON-EQUILIBRIUM, TURBULENT, CHEMICAL MODELS

    SciTech Connect

    Mac Low, Mordecai-Mark; Glover, Simon C. O. E-mail: glover@uni-heidelberg.de

    2012-02-20

    Observations of spiral galaxies show a strong linear correlation between the ratio of molecular to atomic hydrogen surface density R{sub mol} and midplane pressure. To explain this, we simulate three-dimensional, magnetized turbulence, including simplified treatments of non-equilibrium chemistry and the propagation of dissociating radiation, to follow the formation of H{sub 2} from cold atomic gas. The formation timescale for H{sub 2} is sufficiently long that equilibrium is not reached within the 20-30 Myr lifetimes of molecular clouds. The equilibrium balance between radiative dissociation and H{sub 2} formation on dust grains fails to predict the time-dependent molecular fractions we find. A simple, time-dependent model of H{sub 2} formation can reproduce the gross behavior, although turbulent density perturbations increase molecular fractions by a factor of few above it. In contradiction to equilibrium models, radiative dissociation of molecules plays little role in our model for diffuse radiation fields with strengths less than 10 times that of the solar neighborhood, because of the effective self-shielding of H{sub 2}. The observed correlation of R{sub mol} with pressure corresponds to a correlation with local gas density if the effective temperature in the cold neutral medium of galactic disks is roughly constant. We indeed find such a correlation of R{sub mol} with density. If we examine the value of R{sub mol} in our local models after a free-fall time at their average density, as expected for models of molecular cloud formation by large-scale gravitational instability, our models reproduce the observed correlation over more than an order-of-magnitude range in density.

  1. Final Report for Project: Impacts of stratification and non-equilibrium winds and waves on hub-height winds

    SciTech Connect

    Patton, Edward G.

    2015-07-14

    This project used a combination of turbulence-resolving large-eddy simulations, single-column modeling (where turbulence is parameterized), and currently available observations to improve, assess, and develop a parameterization of the impact of non-equilibrium wave states and stratification on the buoy-observed winds to establish reliable wind data at the turbine hub-height level. Analysis of turbulence-resolving simulations and observations illuminates the non-linear coupling between the atmosphere and the undulating sea surface. This analysis guides modification of existing boundary layer parameterizations to include wave influences for upward extrapolation of surface-based observations through the turbine layer. Our surface roughness modifications account for the interaction between stratification and the effects of swell’s amplitude and wavelength as well as swell’s relative motion with respect to the mean wind direction. The single-column version of the open source Weather and Research Forecasting (WRF) model (Skamarock et al., 2008) serves as our platform to test our proposed planetary boundary layer parameterization modifications that account for wave effects on marine atmospheric boundary layer flows. WRF has been widely adopted for wind resource analysis and forecasting. The single column version is particularly suitable to development, analysis, and testing of new boundary layer parameterizations. We utilize WRF’s single-column version to verify and validate our proposed modifications to the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer parameterization (Nakanishi and Niino, 2004). We explore the implications of our modifications for two-way coupling between WRF and wave models (e.g.,Wavewatch III). The newly implemented parameterization accounting for marine atmospheric boundary layer-wave coupling is then tested in three-dimensional WRF simulations at grid sizes near 1 km. These simulations identify the behavior of simulated winds at the

  2. Spectral tailoring device

    DOEpatents

    Brager, H.R.; Schenter, R.E.; Carter, L.L.; Karnesky, R.A.

    1987-08-05

    A spectral tailoring device for altering the neutron energy spectra and flux of neutrons in a fast reactor thereby selectively to enhance or inhibit the transmutation rate of a target metrical to form a product isotope. Neutron moderators, neutron filters, neutron absorbers and neutron reflectors may be used as spectral tailoring devices. Depending on the intended use for the device, a member from each of these four classes of materials could be used singularly, or in combination, to provide a preferred neutron energy spectra and flux of the neutrons in the region of the target material. In one embodiment of the invention, an assembly is provided for enhancing the production of isotopes, such as cobalt 60 and gadolinium 153. In another embodiment of the invention, a spectral tailoring device is disposed adjacent a target material which comprises long lived or volatile fission products and the device is used to shift the neutron energy spectra and flux of neutrons in the region of the fission products to preferentially transmute them to produce a less volatile fission product inventory. 6 figs.

  3. Strong lattice correlation of non-equilibrium quasiparticles in a pseudospin-1/2 Mott insulator Sr2IrO4

    DOE PAGES [OSTI]

    Li, Yuelin; Schaller, Richard D.; Zhu, Mengze; Walko, Donald A.; Kim, Jungho; Ke, Xianglin; Miao, Ludi; Mao, Z. Q.

    2016-01-20

    In correlated oxides the coupling of quasiparticles to other degrees of freedom such as spin and lattice plays critical roles in the emergence of symmetry-breaking quantum ordered states such as high temperature superconductivity. We report a strong lattice coupling of photon-induced quasiparticles in spin-orbital coupling Mott insulator Sr2IrO4 probed via optical excitation. Combining time-resolved x-ray diffraction and optical spectroscopy techniques, we reconstruct a spatiotemporal map of the diffusion of these quasiparticles. Lastly, due to the unique electronic configuration of the quasiparticles, the strong lattice correlation is unexpected but extends the similarity between Sr2IrO4 and cuprates to a new dimension ofmore » electron-phonon coupling which persists under highly non-equilibrium conditions.« less

  4. Tailored Materials Corp | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Zip: 85706 Sector: Carbon, Solar Product: String representation "Tailored Materi ... ng solar cells." is too long. References: Tailored Materials Corp1 This article is a stub....

  5. 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

    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)

    2014-02-28

    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.

  6. Tailored Ceramics for Laser Applications

    SciTech Connect

    Hollingsworth, Joel

    2007-12-10

    Transparent ceramics match or exceed the performance of single-crystal materials in laser applications, with a more-robust fabrication process. Controlling the distribution of optical dopants in transparent ceramics would allow qualitative improvements in amplifier slab design by allowing gain and loss to be varied within the material. My work aims to achieve a controlled pattern or gradient of dopant prior to sintering, in order to produce tailored ceramics.

  7. Tailored Working Fluids for Enhanced Binary Geothermal Power...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Tailored Working Fluids for Enhanced Binary Geothermal Power Plants Tailored Working Fluids for Enhanced Binary Geothermal Power Plants DOE Geothermal Program Peer Review 2010 - ...

  8. High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded...

    Energy Saver

    High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks 2013 DOE Hydrogen and Fuel Cells Program ...

  9. Non-Equilibrium Nanoscale Self-Organization

    SciTech Connect

    Aziz, Michael J

    2006-03-09

    Self-organized one- and two-dimensional arrays of nanoscale surface features ("ripples" and "dots") sometimes form spontaneously on initially flat surfaces eroded by a directed ion beam in a process called "sputter patterning". Experiments on this sputter patterning process with focused and unfocused ion beams, combined with theoretical advances, have been responsible for a number of scientific advances. Particularly noteworthy are (i) the discovery of propagative, rather than dissipative, behavior under some ion erosion conditions, permitting a pattern to be fabricated at a large length scale and propagated over large distances while maintaining, or even sharpening, the sharpest features; (ii) the first demonstration of guided self-organization of sputter patterns, along with the observation that defect density is minimized when the spacing between boundaries is near an integer times the natural spatial period; and (iii) the discovery of metastability of smooth surfaces, which contradicts the nearly universally accepted linear stability theory that predicts that any surface is linearly unstable to sinusoidal perturbations of some wave vector.

  10. 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

    Prevosto, L.; Mancinelli, B.; Kelly, H.; Instituto de Fsica del Plasma , Departamento de Fsica, Facultad de Ciencias Exactas y Naturales Ciudad Universitaria Pab. I, 1428 Buenos Aires

    2013-12-15

    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.

  11. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Wednesday, 29 November 2006 00:00 Researchers at ...

  12. Near-infrared spectroscopy of the Y0 WISEP J173835.52+273258.9 and the Y1 WISE J035000.32–565830.2: The importance of non-equilibrium chemistry

    DOE PAGES [OSTI]

    Leggett, Sandy K.; Tremblin, Patrick; Saumon, Didier; Marley, Mark S.; Morley, Caroline V.; Amundsen, David S.; Baraffe, Isabelle; Chabrier, Gilles

    2016-06-03

    Here, we present new near-infrared spectra, obtained at Gemini Observatory, for two Y dwarfs: WISE J035000.32–565830.2 (W0350) and WISEP J173835.52+273258.9 (W1738). A FLAMINGOS-2 R = 540 spectrum was obtained for W0350, coveringmore » $$1.0\\lt \\lambda \\;\\mu {\\rm{m}}$$ $$\\lt \\;1.7$$, and a cross-dispersed Gemini near-infrared spectrograph R = 2800 spectrum was obtained for W1738, covering 0.993–1.087 μm, 1.191–1.305 μm, 1.589–1.631 μm, and 1.985–2.175 μm, in four orders. We also present revised YJH photometry for W1738, using new NIRI Y and J imaging, and a re-analysis of the previously published NIRI H-band images. We compare these data, together with previously published data for late-T and Y dwarfs, to cloud-free models of solar metallicity, calculated both in chemical equilibrium and with disequilibrium driven by vertical transport. We find that for the Y dwarfs, the non-equilibrium models reproduce the near-infrared data better than the equilibrium models. The remaining discrepancies suggest that fine-tuning the CH4/CO and NH3/N2 balance is needed. Improved trigonometric parallaxes would improve the analysis. Despite the uncertainties and discrepancies, the models reproduce the observed near-infrared spectra well. We find that for the Y0, W1738, $${T}_{{\\rm{eff}}}=425\\pm 25\\;{\\rm{K}}$$, and log $$g=4.0\\pm 0.25$$, and for the Y1, W0350, $${T}_{{\\rm{eff}}}=350\\pm 25\\;{\\rm{K}}$$, and log $$g=4.0\\pm 0.25$$. W1738 may be metal-rich. Based on evolutionary models, these temperatures and gravities correspond to a mass range for both Y dwarfs of 3–9 Jupiter masses, with W0350 being a cooler, slightly older, version of W1738; the age of W0350 is 0.3–3 Gyr, and the age of W1738 is 0.15–1 Gyr.« less

  13. High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks 2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting lm075_hovanski_2013_o.pdf (3.29 MB) More Documents & Publications Vehicle Technologies Office Merit Review 2014: High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks Vehicle Technologies Office

  14. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Researchers at the ... terahertz radiation from a relativistic electron beam modulated by a femtosecond laser. ...

  15. Vehicle Technologies Office Merit Review 2014: Tailored Materials...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Vehicle Technologies Office Merit Review 2014: Tailored Materials for Improved ... at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit ...

  16. Engineering Property Prediction Tools for Tailored Polymer Composite...

    Energy.gov [DOE] (indexed site)

    (1.96 MB) More Documents & Publications Engineering Property Prediction Tools for Tailored Polymer Composite Structures 2011 Annual Progress Report for ...

  17. Engineering Property Prediction Tools for Tailored Polymer Composite...

    Energy.gov [DOE] (indexed site)

    Engineering Property Prediction Tools for Tailored Polymer Composite Structures Vehicle Technologies Office Merit Review 2014: Predictive Engineering Tools for Injection-Molded ...

  18. Tailored Materials for High Efficiency CIDI Engines (Caterpillar...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    High Efficiency CIDI Engines (Caterpillar CRADA) Tailored Materials for High Efficiency CIDI Engines (Caterpillar CRADA) 2009 DOE Hydrogen Program and Vehicle Technologies Program ...

  19. Tailored Materials for Advanced CIDI Engines | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Advanced CIDI Engines Tailored Materials for Advanced CIDI Engines 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer ...

  20. Tailored Recovery of Carbons from Waste Tires for Enhanced Performance...

    Office of Scientific and Technical Information (OSTI)

    Morphologically tailored pyrolysis-recovered carbon black is utilized in lithium-ion ... Carbon was recovered from the modified rubber cake by pyrolysis in a nitrogen atmosphere. ...

  1. Tailoring the properties of organic aerogels

    SciTech Connect

    Not Available

    1993-05-01

    We have recently succeeded in producing a new class of organic (or carbon) aerogels whose electrical, mechanical, and other properties are superior to those of the metal alkoxides. By tailoring properties to specific applications, we hope to achieve aerogels with even better performance. We have already tested carbon aerogels for use in inertial-confinement fusion targets and are currently studying applications to other technologies, such as battery electrodes, catalyst supports, and gas filters. In several of these applications, the permeability of the carbon aerogels-that is, their resistance to fluid flow-is crucial to their performance. Here, we describe briefly the synthesis of organic aerogels and present the results of our permeability studies.

  2. Tailored Marketing for Low-income and Under-Represented Population...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Tailored Marketing for Low-income and Under-Represented Population Segments (201) Tailored Marketing for Low-income and Under-Represented Population Segments (201) Better Buildings ...

  3. Tailored Materials for High Efficiency CIDI Engines

    SciTech Connect

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  4. Tailoring Nanostructures for Energy Conversion Devices | Solid State Solar

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Thermal Energy Conversion Tailoring Nanostructures for Energy Conversion Devices Seminar Thursday Oct 20, 2016 12:00pm Location: 4-163 Speaker: Prof. Jia Zhu, Nanjing University Event Contact: sborisk@mit.edu Supplying the world with sustainable energy is one of the most pressing issues in modern society. Nanomaterials with carefully tailored properties (such as interface, impurities) can be used to manipulate the flow of phonons, electrons and photons, to enable novel energy devices in an

  5. Tailored Working Fluids for Enhanced Binary Geothermal Power Plants

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE Geothermal Program Peer Review 2010 - Presentation. Project Objective: To improve the utilization of available energy in geothermal resources and increase the energy conversion efficiency of systems employed by a) tailoring the subcritical and/or supercritical glide of enhanced working fluids to best match thermal resources, and b) identifying appropriate thermal system and component designs for the down-selected working fluids.

  6. Recent progress in tailoring trap-based positron beams

    SciTech Connect

    Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M.

    2013-03-19

    Recent progress is described to implement two approaches to specially tailor trap-based positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 {>=} T {>=} 300 K. These simulations are also used to predict beam performance for cryogenically cooled positrons. Experiments and simulations are also presented to understand the properties of beams formed when plasmas are tailored in a PM trap in a 5 tesla magnetic field, then non-adiabatically extracted from the field using a specially designed high-permeability grid to create a new class of electrostatically guided beams.

  7. Tailorable infrared sensing device with strain layer superlattice structure

    DOEpatents

    Cheng, Li-Jen

    1987-12-08

    An infrared photodetector is formed of a heavily doped p-type Ge.sub.x Si.sub.1-x /Si superlattice in which x is pre-established during manufacture in the range 0 to 100 percent. A custom tailored photodetector that can differentiate among close wavelengths in the range of 2.7 to 50 microns is fabricated by appropriate selection of the alloy constituency value, x, to establish a specific wavelength at which photodetection cut-off will occur.

  8. High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks YURI HOVANSKI April 10, 2013 This Presentation does not contain any proprietary, confidential, or otherwise restricted information Project ID #LM075 Pacific Northwest National Laboratory May 15, 2013 Project Overview OEM GM Tier I Supplier TWB Company LLC Material Provider Alcoa April 10, 2013 2 2 Start: FY2012 Finish: FY2014 33% complete Capacity to rapidly join Al sheet in dissimilar thicknesses and alloys is not developed. Supply

  9. High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Annual Merit Review High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks YURI HOVANSKI This Presentation does not contain any proprietary, confidential, or otherwise restricted information Project ID #LM099 Pacific Northwest National Laboratory June 12, 2015 Project Overview Automotive OEM GM Tier I Supplier TWB Company LLC Material Provider Alcoa 2 2 Start: FY2015 Finish: FY2017 15% complete Capacity to rapidly join dissimilar alloy Al sheet is not developed for high volume production.

  10. High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Annual Merit Review High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks YURI HOVANSKI This Presentation does not contain any proprietary, confidential, or otherwise restricted information Project ID #LM099 Pacific Northwest National Laboratory June 2016 Project Overview National Laboratory PNNL (lead) Automotive OEM GM Tier I Supplier TWB Company LLC Material Provider Alcoa 2 2 Start: FY2015 Finish: FY2017 43% complete Capacity to rapidly join dissimilar alloy Al sheet is not developed

  11. Non-Equilibrium Pathways during Electrochemical Phase Transformations...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    of the active material and its concentration in the composite electrode architecture. ... Figure 1. (Upper panel) Schematic illustration of operando FF TXM-XANES. Electrochemistry ...

  12. Non-equilibrium electronic and phononic specific heat in systems...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: AC04-94AL85000 Resource Type: Journal Article Resource Relation: Journal Name: Applied Physics Letters; Related Information: Proposed for publication in ...

  13. Fe Atomic Data for Non-equilibrium Ionization Plasmas (Conference...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: AtomDB Work Week and Workshop ; 2012-08-06 - 2012-08-10 ; Cambridge, Massachusetts, United States Research Org: Los Alamos National Laboratory (LANL) ...

  14. Modeling non-equilibrium phase transitions in isentropically...

    Office of Scientific and Technical Information (OSTI)

    The pressure drive is deduced by back integration of VISAR data from shots performed with Al samples. Authors: Kane, J ; Smith, R Publication Date: 2005-09-19 OSTI Identifier: ...

  15. Transport properties of non-equilibrium metallic alloys

    SciTech Connect

    Wong, K.M.M.

    1987-01-01

    A systematic and quantitative study of upper critical fields, H/sub C2/(T), in disordered bulk alloys with increasing atomic numbers was carried out. They include alloys of Ti-Mo, Ti-Pd, Zr-Mo, Zr-Pd, Zr-Rh, Hf-Mo, and Hf-Ta. A least-squares fitting routine was performed on H/sub C2/(T) with the Werthamer, Helfand, Hohenberg, and Maki theory of dirty superconductors. The localization effects on H/sub C2/(T) were examined by comparing the electronic density of states obtained from specific heat measurements (absence of field-induced delocalization effects) and those derived from fitting critical field data. Measurements on bulk Zr-Ni, Zr-Rh and Hf-Mo alloys gave the first direct confirmation of theoretical predictions on H/sub C2/(T) for the weakly localized 3D systems. To further test the localization theories, magnetoresistance was measured on amorphous Lu-Pd and Lu-Ni alloys. The author also investigated a wide compositional range of U-Fe, U-Co, and U-Ni metallic glasses which contain f-electrons. These uranium glasses exhibit unusual resistivity and superconducting behaviors and have very large upper-critical-field gradients.

  16. Non-Equilibrium Magnetohydrodynamic Behavior of Plasmas having...

    Office of Scientific and Technical Information (OSTI)

    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...

  17. Fe Atomic Data for Non-equilibrium Ionization Plasmas (Conference...

    Office of Scientific and Technical Information (OSTI)

    1 ; Hungerford, Aimee L. 1 ; Fryer, Christopher L. 1 ; Hughes, John P. 2 ; Smith, Randall K. 3 ; Badenes, Carles 4 + Show Author Affiliations Los Alamos National ...

  18. Non-equilibrium chemical partitioning calculation for phase transforma...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    and time dependent phase selection. The calculation programs were developed in C++ and fortran. In this program, we will integrate the existing calculation programs. Research area:...

  19. Non-Equilibrium Magnetohydrodynamic Behavior of Plasmas having...

    Office of Scientific and Technical Information (OSTI)

    of Plasmas having Complex, Evolving Morphology Citation Details In-Document Search ... Country of Publication: United States Language: English Subject: 70 PLASMA PHYSICS AND ...

  20. Modeling non-equilibrium phase transitions in isentropically...

    Office of Scientific and Technical Information (OSTI)

    In the experiments, the Bi samples are attached to windows of LiF or sapphire, and the velocity history of the sample-window interface is recorded with line VISAR. The 1D response ...

  1. Forty years of molecular electronics: Non-equilibrium heat and...

    Office of Scientific and Technical Information (OSTI)

    Volume: 250; Related Information: CBES partners with Northwestern University (lead); Harvard University; New York University; Pennsylvania State University; University of...

  2. Equilibrium and non-equilibrium emission of complex fragments

    SciTech Connect

    Bowman, D.R.

    1989-08-01

    Complex fragment emission (Z{gt}2) has been studied in the reactions of 50, 80, and 100 MeV/u {sup 139}La + {sup 12}C, and 80 MeV/u {sup 139}La + {sup 27}Al, {sup nat}Cu, and {sup 197}Au. Charge, angle, and energy distributions were measured inclusively and in coincidence with other complex fragments, and were used to extract the source rapidities, velocity distributions, and cross sections. The experimental emission velocity distributions, charge loss distributions, and cross sections have been compared with calculations based on statistical compound nucleus decay. The binary signature of the coincidence events and the sharpness of the velocity distributions illustrate the primarily 2-body nature of the {sup 139}La + {sup 12}C reaction mechanism between 50 and 100 MeV/u. The emission velocities, angular distributions, and absolute cross sections of fragments of 20{le}Z{le}35 at 50 MeV/u, 19{le}Z{le}28 at 80 MeV/u, and 17{le}Z{le}21 at 100 MeV/u indicate that these fragments arise solely from the binary decay of compound nuclei formed in incomplete fusion reactions in which the {sup 139}La projectile picks up about one-half of the {sup 12}C target. In the 80 MeV/u {sup 139}La + {sup 27}Al, {sup nat}Cu, and {sup 197}Au reactions, the disappearance of the binary signature in the total charge and velocity distributions suggests and increase in the complex fragment and light charged particle multiplicity with increasing target mass. As in the 80 and 100 MeV/u {sup 139}La + {sup 12}C reactions, the lighter complex fragments exhibit anisotropic angular distributions and cross sections that are too large to be explained exclusively by statistical emission. 143 refs., 67 figs.

  3. Tailoring oxidation degrees of graphene oxide by simple chemical reactions

    SciTech Connect

    Wang Gongkai; Sun Xiang; Lian Jie; Liu Changsheng

    2011-08-01

    High quality graphene oxide (GO) with controllable degrees of oxidation was synthesized by simple chemical reactions inspired by approaches to unzip single wall carbon nanotubes using strong oxidizing agents. As compared to the conventional Hummers method, these reactions are less exo-therm involved without emission of toxic gases. The structural characteristics of the synthesized GO with various oxidation degrees were evaluated by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, thermal gravimetric analysis, and UV-vis-IR spectroscopy. GO with tailored degrees of oxidation displays tunable optoelectronic properties and may have a significant impact on developing graphene- or GO-based platforms for various technological applications.

  4. Vehicle Technologies Office Merit Review 2014: Active, Tailorable Adhesives for Dissimilar Material Bonding, Repair and Assembly

    Energy.gov [DOE]

    Presentation given by Michigan State University at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about Active, tailorable...

  5. Vehicle Technologies Office Merit Review 2015: Active, Tailorable Adhesives for Dissimilar Material Bonding, Repair and Assembly

    Energy.gov [DOE]

    Presentation given by Michigan State University at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about active, tailorable...

  6. Tailored Marketing for Low-income and Under-Represented Population Segments (201)

    Energy.gov [DOE]

    Better Buildings Residential Network Peer Exchange Call Series: Tailored Marketing for Low-Income and Under-Represented Population Segments (201), call slides and discussion summary.

  7. Model for the Fabrication of Tailored Materials for Lithium-Ion...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Model for the Fabrication of Tailored Materials for Lithium-Ion Batteries Technology available for licensing: Safe, stable and high-capacity cathodes for lithium-ion batteries ...

  8. Tailoring the slow light behavior in terahertz metasurfaces

    SciTech Connect

    Manjappa, Manukumara; Cong, Longqing; Singh, Ranjan; Chiam, Sher-Yi; Bettiol, Andrew A.; Zhang, Weili

    2015-05-04

    We experimentally study the effect of near field coupling on the transmission of light in terahertz metasurfaces. Our results show that tailoring the coupling between the resonators modulates the amplitude of resulting electromagnetically induced transmission, probed under different types of asymmetries in the coupled system. Observed change in the transmission amplitude is attributed to the change in the amount of destructive interference between the resonators in the vicinity of strong near field coupling. We employ a two-particle model to theoretically study the influence of the coupling between bright and quasi-dark modes on the transmission properties of the system and we find an excellent agreement with our observed results. Adding to the enhanced transmission characteristics, our results provide a deeper insight into the metamaterial analogues of atomic electromagnetically induced transparency and offer an approach to engineer slow light devices, broadband filters, and attenuators at terahertz frequencies.

  9. High gain photoconductive semiconductor switch having tailored doping profile zones

    DOEpatents

    Baca, Albert G.; Loubriel, Guillermo M.; Mar, Alan; Zutavern, Fred J; Hjalmarson, Harold P.; Allerman, Andrew A.; Zipperian, Thomas E.; O'Malley, Martin W.; Helgeson, Wesley D.; Denison, Gary J.; Brown, Darwin J.; Sullivan, Charles T.; Hou, Hong Q.

    2001-01-01

    A photoconductive semiconductor switch with tailored doping profile zones beneath and extending laterally from the electrical contacts to the device. The zones are of sufficient depth and lateral extent to isolate the contacts from damage caused by the high current filaments that are created in the device when it is turned on. The zones may be formed by etching depressions into the substrate, then conducting epitaxial regrowth in the depressions with material of the desired doping profile. They may be formed by surface epitaxy. They may also be formed by deep diffusion processes. The zones act to reduce the energy density at the contacts by suppressing collective impact ionization and formation of filaments near the contact and by reducing current intensity at the contact through enhanced current spreading within the zones.

  10. Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring

    SciTech Connect

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Panasenko, Dmitriy; Shiraishi, Satomi; Sokollik, Thomas; Benedetti, Carlo; Schroeder, Carl; Geddes, Cameron; Tilborg, Jeroen van; Osterhoff, Jens; Esarey, Eric; Toth, Csaba; Leemans, Wim

    2011-07-15

    Laser plasma accelerators have produced high-quality electron beams with GeV energies from cm-scale devices and are being investigated as hyperspectral fs light sources producing THz to {gamma}-ray radiation and as drivers for future high-energy colliders. These applications require a high degree of stability, beam quality and tunability. Here we report on a technique to inject electrons into the accelerating field of a laser-driven plasma wave and coupling of this injector to a lower-density, separately tunable plasma for further acceleration. The technique relies on a single laser pulse powering a plasma structure with a tailored longitudinal density profile, to produce beams that can be tuned in the range of 100-400 MeV with percent-level stability, using laser pulses of less than 40 TW. The resulting device is a simple stand-alone accelerator or the front end for a multistage higher-energy accelerator.

  11. Tailoring dielectric properties of ferroelectric-dielectric multilayers

    SciTech Connect

    Kesim, M. T.; Zhang, J.; Cole, M. W.; Misirlioglu, I. B.

    2014-01-13

    We develop a nonlinear thermodynamic model for multilayer ferroelectric heterostructures that takes into account electrostatic and electromechanical interactions between layers. We concentrate on the effect of relative layer fractions and in-plane thermal stresses on dielectric properties of Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}-, BaTiO{sub 3}-, and PbZr{sub 0.2}Ti{sub 0.8}O{sub 3} (PZT)-SrTiO{sub 3} (STO) multilayers on Si and c-sapphire. We show that dielectric properties of such multilayers can be significantly enhanced by tailoring the growth/processing temperature and the STO layer fraction. Our computations show that large tunabilities (?90% at 400?kV/cm) are possible in carefully designed barium strontium titanate-STO and PZT-STO even on Si for which there exist substantially large in-plane strains.

  12. Tailoring dielectric resonator geometries for directional scattering and Huygens metasurfaces

    DOE PAGES [OSTI]

    Campione, Salvatore; Basilio, Lorena I.; Warne, Larry K.; Sinclair, Michael B.

    2015-01-28

    In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity dielectric cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometrymorein a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole resonances to achieve local behavior. These properties are confirmed through the multipolar expansion and show that the use of geometries suggested by perturbation theory is a viable route to achieve purely dipole resonances for metamaterial applications such as wave-front manipulation with Huygens metasurfaces. Our results are fully scalable across any frequency bands where high-permittivity dielectric materials are available, including microwave, THz, and infrared frequencies.less

  13. Chemical tailoring of steam to remediate underground mixed waste contaminents

    DOEpatents

    Aines, Roger D.; Udell, Kent S.; Bruton, Carol J.; Carrigan, Charles R.

    1999-01-01

    A method to simultaneously remediate mixed-waste underground contamination, such as organic liquids, metals, and radionuclides involves chemical tailoring of steam for underground injection. Gases or chemicals are injected into a high pressure steam flow being injected via one or more injection wells to contaminated soil located beyond a depth where excavation is possible. The injection of the steam with gases or chemicals mobilizes contaminants, such as metals and organics, as the steam pushes the waste through the ground toward an extraction well having subatmospheric pressure (vacuum). The steam and mobilized contaminants are drawn in a substantially horizontal direction to the extraction well and withdrawn to a treatment point above ground. The heat and boiling action of the front of the steam flow enhance the mobilizing effects of the chemical or gas additives. The method may also be utilized for immobilization of metals by using an additive in the steam which causes precipitation of the metals into clusters large enough to limit their future migration, while removing any organic contaminants.

  14. Marketing to Win: How to Identify the Real Decision-maker and Tailor Your

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Message | Department of Energy Marketing to Win: How to Identify the Real Decision-maker and Tailor Your Message Marketing to Win: How to Identify the Real Decision-maker and Tailor Your Message Presented at the 15th Annual DOE Small Business Forum & Expo by: Gloria Larkin, President TargetGov Marketing to Win: How to Identify the Real Decision-maker and Tailor Your Message (4.06 MB) More Documents & Publications Presentations from the 12th Annual Small Business Conference, May 2011

  15. EXC-12-0007- In the Matter of Tailored Lighting, Inc.

    Energy.gov [DOE]

    On October 23, 2012, OHA issued a decision considering an Application for Exception filed by Tailored Lighting, Inc. (TLI) for relief from the provisions of 10 C.F.R. Part 430, Energy Conservation...

  16. Tailored light-matter interaction through epsilon-near-zero modes.

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Tailored light-matter interaction through epsilon-near-zero modes. Citation Details In-Document Search Title: Tailored light-matter interaction through epsilon-near-zero modes. Abstract not provided. Authors: campione, salvatore ; Liu, Sheng ; Benz, Alexander ; Klem, John Frederick ; Sinclair, Michael B. ; Brener, Igal Publication Date: 2014-12-01 OSTI Identifier: 1315705 Report Number(s): SAND2014-20387C 547726 DOE Contract Number: AC04-94AL85000

  17. Multiple soliton self-frequency shift cancellations in a temporally tailored photonic crystal fiber

    SciTech Connect

    Liu, Lai; Kang, Zhe; Li, Qing; Gao, Xuejian; Qin, Guanshi E-mail: wpqin@jlu.edu.cn; Qin, Weiping E-mail: wpqin@jlu.edu.cn; Liao, Meisong; Hu, Lili; Ohishi, Yasutake

    2014-11-03

    We report the generation of multiple soliton self-frequency shift cancellations in a temporally tailored tellurite photonic crystal fiber (PCF). The temporally regulated group velocity dispersion (GVD) is generated in the fiber by soliton induced optical Kerr effect. Two red-shifted dispersive waves spring up when two Raman solitons meet their own second zero-dispersion-wavelengths in the PCF. These results show how, through temporally tailored GVD, nonlinearities can be harnessed to generate unexpected effects.

  18. Tailoring double Fano profiles with plasmon-assisted quantum interference in hybrid exciton-plasmon system

    SciTech Connect

    Zhao, Dongxing; Wu, Jiarui; Gu, Ying Gong, Qihuang

    2014-09-15

    We propose tailoring of the double Fano profiles via plasmon-assisted quantum interference in a hybrid exciton-plasmon system. Tailoring is performed by the interference between two exciton channels interacting with a common localized surface plasmon. Using an applied field of low intensity, the absorption spectrum of the hybrid system reveals a double Fano lineshape with four peaks. For relatively large field intensity, a broad flat window in the absorption spectrum appears which results from the destructive interference between excitons. Because of strong constructive interference, this window vanishes as intensity is further increased. We have designed a nanometer bandpass optical filter for visible light based on tailoring of the optical spectrum. This study provides a platform for quantum interference that may have potential applications in ultracompact tunable quantum devices.

  19. Comparing Laser Welding Technologies with Friction Stir Welding for Production of Aluminum Tailor-Welded Blanks

    SciTech Connect

    Hovanski, Yuri; Carsley, John; Carlson, Blair; Hartfield-Wunsch, Susan; Pilli, Siva Prasad

    2014-01-15

    A comparison of welding techniques was performed to determine the most effective method for producing aluminum tailor-welded blanks for high volume automotive applications. Aluminum sheet was joined with an emphasis on post weld formability, surface quality and weld speed. Comparative results from several laser based welding techniques along with friction stir welding are presented. The results of this study demonstrate a quantitative comparison of weld methodologies in preparing tailor-welded aluminum stampings for high volume production in the automotive industry. Evaluation of nearly a dozen welding variations ultimately led to down selecting a single process based on post-weld quality and performance.

  20. Tailored light-matter interaction through epsilon-near-zero modes.

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Tailored light-matter interaction through epsilon-near-zero modes. Citation Details In-Document Search Title: Tailored light-matter interaction through epsilon-near-zero modes. Abstract not provided. Authors: campione, salvatore ; Liu, Sheng ; Benz, Alexander ; Klem, John F. ; Sinclair, Michael B. ; Brener, Igal Publication Date: 2015-05-01 OSTI Identifier: 1258099 Report Number(s): SAND2015-3805C 583947 DOE Contract Number: AC04-94AL85000 Resource Type:

  1. Tailored light-matter interaction through epsilon-near-zero modes.

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Tailored light-matter interaction through epsilon-near-zero modes. Citation Details In-Document Search Title: Tailored light-matter interaction through epsilon-near-zero modes. Abstract not provided. Authors: campione, salvatore ; Liu, Sheng ; Benz, Alexander ; Klem, John F. ; Sinclair, Michael B. ; Brener, Igal Publication Date: 2015-05-01 OSTI Identifier: 1258224 Report Number(s): SAND2015-3805C 583947 DOE Contract Number: AC04-94AL85000 Resource Type:

  2. Anthraquinone with Tailored Structure for Nonaqueous Metal-Organic Redox Flow Battery

    SciTech Connect

    Wang, Wei; Xu, Wu; Cosimbescu, Lelia; Choi, Daiwon; Li, Liyu; Yang, Zhenguo

    2012-06-08

    A nonaqueous, hybrid metal-organic redox flow battery based on tailored anthraquinone structure is demonstrated to have an energy efficiency of {approx}82% and a specific discharge energy density similar to aqueous redox flow batteries, which is due to the significantly improved solubility of anthraquinone in supporting electrolytes.

  3. Computational Nanophotonics: Model Optical Interactions and Transport in Tailored Nanosystem Architectures

    SciTech Connect

    Stockman, Mark; Gray, Steven

    2014-02-21

    The program is directed toward development of new computational approaches to photoprocesses in nanostructures whose geometry and composition are tailored to obtain desirable optical responses. The emphasis of this specific program is on the development of computational methods and prediction and computational theory of new phenomena of optical energy transfer and transformation on the extreme nanoscale (down to a few nanometers).

  4. Initial tensile test results from J316 stainless steel irradiated in the HFIR spectrally tailored experiment

    SciTech Connect

    Pawel, J.E.; Grossbeck, M.L.; Rowcliffe, A.F.

    1995-04-01

    The objective of this work is to determine the effects of neutron irradiation on the mechanical properties of austenitic stainless steel alloys. In this experiment, the spectrum has been tailored to reduce the thermal neutron flux and achieve a He/dpa level near that expected in a fusion reactor.

  5. Formation of electron bunches with tailored current profiles using multi-frequency linacs

    SciTech Connect

    Piot, P.; Behrens, C.; Gerth, C.; Lemery, F.; Mihalcea, D.; Stoltz, P.

    2012-12-21

    Tailoring an electron bunch with specific current profile can provide substantial enhancement of the transformer ratio in beam-driven acceleration methods. We present a method relying on the use of a linac with accelerating sections operating at different frequencies followed by a magnetic bunch compressor. The experimental verfification of the technique in a two-frequency linac is presented. The compatibility of the proposed technique with the formation and acceleration of a drive and witness bunches is numerically demonstrated.

  6. Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

    SciTech Connect

    Xu, Wei; Li, Yani; Yu, Bo; Yang, Jindou; Zhang, Ying; Chen, Xi; Zhang, Guofang Gao, Ziwei

    2015-01-15

    A successive anchoring of Ti(NMe{sub 2}){sub 4}, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1′-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, {sup 13}C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands. - Graphical abstract: The ligand-tailored silica supported “single site” titanium complexes were synthesized by SOMC strategy and fully characterized. Their catalytic activity were evaluated by benzaldehyde silylcyanation. - Highlights: • Single-site silica supported Ti active species was prepared by SOMC technique. • O-donor ligand tailored Ti surface species was synthesized. • The surface species was characterized by XPS, {sup 13}C CP-MAS NMR, XANES etc. • Catalytic activity of the Ti active species in silylcyanation reaction was evaluated.

  7. Marketing_to_Win_How_to_Identify_the_Real_Decision_makers_and_Tailor_Your_Message

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Marketing to Win: How to Identify the Real Decision-makers and Tailor Your Message Gloria Larkin President, TargetGov 1 ©TargetGov 2016 2 Agenda * Disappearing act * First impressions * Mitigating risks * Identifying real decision makers * Layers of decision makers * How and why they choose * Marketing and positioning tools ©TargetGov 2016 Disappearing Act? * In 2000, $200 Billion in Contracts - Over 100,000 contracting and acquisition staff * In 2013, $500 Billion in contracts - Fewer than

  8. Material system for tailorable white light emission and method for making thereof

    DOEpatents

    Smith, Christine A.; Lee, Howard W.

    2004-08-10

    A method of processing a composite material to tailor white light emission of the resulting composite during excitation. The composite material is irradiated with a predetermined power and for a predetermined time period to reduce the size of a plurality of nanocrystals and the number of a plurality of traps in the composite material. By this irradiation process, blue light contribution from the nanocrystals to the white light emission is intensified and red and green light contributions from the traps are decreased.

  9. Material system for tailorable white light emission and method for making thereof

    DOEpatents

    Smith, Christine A.; Lee, Howard W. H.

    2009-05-19

    A method of processing a composite material to tailor white light emission of the resulting composite during excitation. The composite material is irradiated with a predetermined power and for a predetermined time period to reduce the size of a plurality of nanocrystals and the number of a plurality of traps in the composite material. By this irradiation process, blue light contribution from the nanocrystals to the white light emission is intensified and red and green light contributions from the traps are decreased.

  10. Synthetic Biology for Tailored Enzyme Cocktails Presentation for BETO 2015 Project Peer Review

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    March 2015 SynTec Synthetic Biology for Tailored Enzyme Cocktails DOE Bioenergy Technologies Office (BETO) 2015 Project Peer Review Biochemical Conversion Sarah Teter Novozymes, Inc This presentation does not contain any proprietary, confidential, or otherwise restricted information NOVOZYMES PRESENTATION 26 Mar 2015 2 ACCELERATE INNOVATION IN ENZYME DISCOVERY REDUCE COSTS FOR PRODUCING CELLULOSIC SUGARS  Deliver a screening platform which can be used to reduce discovery time required for

  11. Computational model, method, and system for kinetically-tailoring multi-drug chemotherapy for individuals

    DOEpatents

    Gardner, Shea Nicole

    2007-10-23

    A method and system for tailoring treatment regimens to individual patients with diseased cells exhibiting evolution of resistance to such treatments. A mathematical model is provided which models rates of population change of proliferating and quiescent diseased cells using cell kinetics and evolution of resistance of the diseased cells, and pharmacokinetic and pharmacodynamic models. Cell kinetic parameters are obtained from an individual patient and applied to the mathematical model to solve for a plurality of treatment regimens, each having a quantitative efficacy value associated therewith. A treatment regimen may then be selected from the plurlaity of treatment options based on the efficacy value.

  12. Observables can be tailored to change the entanglement of any pure state

    SciTech Connect

    Harshman, N. L.; Ranade, Kedar S.

    2011-07-15

    We show that, for a finite-dimensional Hilbert space, there exist observables that induce a tensor product structure such that the entanglement properties of any pure state can be tailored. In particular, we provide an explicit, finite method for constructing observables in an unstructured d-dimensional system so that an arbitrary known pure state has any Schmidt decomposition with respect to an induced bipartite tensor product structure. In effect, this article demonstrates that, in a finite-dimensional Hilbert space, entanglement properties can always be shifted from the state to the observables and all pure states are equivalent as entanglement resources in the ideal case of complete control of observables.

  13. Evaluation of Aeroelastically Tailored Small Wind Turbine Blades Final Project Report

    SciTech Connect

    Griffin, Dayton A.

    2005-09-29

    Evaluation of Aeroelastically Tailored Small Wind Turbine Blades Final Report Global Energy Concepts, LLC (GEC) has performed a conceptual design study concerning aeroelastic tailoring of small wind turbine blades. The primary objectives were to evaluate ways that blade/rotor geometry could be used to enable cost-of-energy reductions by enhancing energy capture while constraining or mitigating blade costs, system loads, and related component costs. This work builds on insights developed in ongoing adaptive-blade programs but with a focus on application to small turbine systems with isotropic blade material properties and with combined blade sweep and pre-bending/pre-curving to achieve the desired twist coupling. Specific goals of this project are to: (A) Evaluate and quantify the extent to which rotor geometry can be used to realize load-mitigating small wind turbine rotors. Primary aspects of the load mitigation are: (1) Improved overspeed safety affected by blades twisting toward stall in response to speed increases. (2) Reduced fatigue loading affected by blade twisting toward feather in response to turbulent gusts. (B) Illustrate trade-offs and design sensitivities for this concept. (C) Provide the technical basis for small wind turbine manufacturers to evaluate this concept and commercialize if the technology appears favorable. The SolidWorks code was used to rapidly develop solid models of blade with varying shapes and material properties. Finite element analyses (FEA) were performed using the COSMOS code modeling with tip-loads and centripetal accelerations. This tool set was used to investigate the potential for aeroelastic tailoring with combined planform sweep and pre-curve. An extensive matrix of design variables was investigated, including aerodynamic design, magnitude and shape of planform sweep, magnitude and shape of blade pre-curve, material stiffness, and rotor diameter. The FEA simulations resulted in substantial insights into the structural

  14. Non-Equilibrium Superconductivity and Quasiparticle Dynamics in YBaCuO

    SciTech Connect

    Siders, J.L.W.; Jacobs, R.N.; Siders, C.W.; Trugman, S.A.; Taylor, A.J.

    1999-05-21

    The authors use optical pump, coherent terahertz probe spectroscopy to transiently excite nonequilibrium populations of quasiparticles in YBa{sub 2}Cu{sub 3}O{sub 7.{delta}} and monitor, with picosecond resolution, the superfluid and quasiparticle dynamics.

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

    SciTech Connect

    Bellan, Paul M.

    2014-03-13

    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.

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

    SciTech Connect

    Leonard, T.; Lander, B.; Seifert, U.; Speck, T.

    2013-11-28

    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.

  17. Systematic validation of non-equilibrium thermochemical models using Bayesian inference

    SciTech Connect

    Miki, Kenji; Panesi, Marco; Prudhomme, Serge

    2015-10-01

    The validation process proposed by Babuška et al. [1] is applied to thermochemical models describing post-shock flow conditions. In this validation approach, experimental data is involved only in the calibration of the models, and the decision process is based on quantities of interest (QoIs) predicted on scenarios that are not necessarily amenable experimentally. Moreover, uncertainties present in the experimental data, as well as those resulting from an incomplete physical model description, are propagated to the QoIs. We investigate four commonly used thermochemical models: a one-temperature model (which assumes thermal equilibrium among all inner modes), and two-temperature models developed by Macheret et al. [2], Marrone and Treanor [3], and Park [4]. Up to 16 uncertain parameters are estimated using Bayesian updating based on the latest absolute volumetric radiance data collected at the Electric Arc Shock Tube (EAST) installed inside the NASA Ames Research Center. Following the solution of the inverse problems, the forward problems are solved in order to predict the radiative heat flux, QoI, and examine the validity of these models. Our results show that all four models are invalid, but for different reasons: the one-temperature model simply fails to reproduce the data while the two-temperature models exhibit unacceptably large uncertainties in the QoI predictions.

  18. Non-equilibrium dynamics in disordered materials: Ab initio molecular dynamics simulations

    SciTech Connect

    Ohmura, Satoshi; Nagaya, Kiyonobu; Yao, Makoto; Shimojo, Fuyuki

    2015-08-17

    The dynamic properties of liquid B{sub 2}O{sub 3} under pressure and highly-charged bromophenol molecule are studied by using molecular dynamics (MD) simulations based on density functional theory (DFT). Diffusion properties of covalent liquids under high pressure are very interesting in the sense that they show unexpected pressure dependence. It is found from our simulation that the magnitude relation of diffusion coefficients for boron and oxygen in liquid B{sub 2}O{sub 3} shows the anomalous pressure dependence. The simulation clarified the microscopic origin of the anomalous diffusion properties. Our simulation also reveals the dissociation mechanism in the coulomb explosion of the highly-charged bromophenol molecule. When the charge state n is 6, hydrogen atom in the hydroxyl group dissociates at times shorter than 20 fs while all hydrogen atoms dissociate when n is 8. After the hydrogen dissociation, the carbon ring breaks at about 100 fs. There is also a difference on the mechanism of the ring breaking depending on charge states, in which the ring breaks with expanding (n = 6) or shrink (n = 8)

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

    SciTech Connect

    Malhotra, Vivak

    2014-06-30

    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.

  20. Relationship between population dynamics and the self-energy in driven non-equilibrium systems

    DOE PAGES [OSTI]

    Kemper, Alexander F.; Freericks, James K.

    2016-05-13

    We compare the decay rates of excited populations directly calculated within a Keldysh formalism to the equation of motion of the population itself for a Hubbard-Holstein model in two dimensions. While it is true that these two approaches must give the same answer, it is common to make a number of simplifying assumptions, within the differential equation for the populations, that allows one to interpret the decay in terms of hot electrons interacting with a phonon bath. Furthermore, we show how care must be taken to ensure an accurate treatment of the equation of motion for the populations due tomore » the fact that there are identities that require cancellations of terms that naively look like they contribute to the decay rates. In particular, the average time dependence of the Green's functions and self-energies plays a pivotal role in determining these decay rates.« less

  1. Non-equilibrium atmospheric pressure microplasma jet: An approach to endoscopic therapies

    SciTech Connect

    Zuo, Xiao; Wei, Yu; Wei Chen, Long; Dong Meng, Yue; Collaboration: Plasma Medicine Team

    2013-08-15

    Atmospheric pressure microplasma jet generated in a long hollow core optical fiber is studied to verify the potential feasibility of endoscopic therapies. Thermal damage and electric shock to the human body were suppressed by two technical methods, i.e., the high-voltage resistant flexible tube wrapped on the optical fiber and a power resistor of 100 k? connected between the power supply and the copper foil electrode. Optical emission spectra analysis indicated that many kinds of active radicals like excited atomic O and OH, were generated in the microplasma jet. In addition, the applications of the microplasma jet on sterilization and lung cancer cell apoptosis were presented. After 5 min of exposures to the microplasma jet, the cell viability and the bacillus subtilis replication decreased to about 3% and zero, respectively. More investigations are needed to improve the plasma-aided endoscopic therapies.

  2. Microscopic analysis of non-equilibrium dynamics in the semiconductor-laser gain medium

    SciTech Connect

    Hader, J.; Moloney, J. V.; Koch, S. W.

    2014-04-14

    Fully microscopic many-body calculations are used to analyze the carrier dynamics in situations where a strong sub-picosecond pulse interacts with an inverted semiconductor quantum well. Electron-electron and electron-phonon scatterings are calculated on a second Born-Markov level. Intra-subband scatterings on a scale of tens of femtoseconds are shown to quickly re-fill the kinetic holes created in the carrier distributions during the pulse amplification. Even for sub-100 fs pulses, this significantly influences the pulse amplification as well as its spectral dependence. Interband scatterings on a few picosecond timescale limit the possibly achievable repetition rate in pulsed semiconductor lasers.

  3. The behavior of matter under non-equilibrium conditions: Fundamental aspects and applications

    SciTech Connect

    Prigogine, I.

    1992-04-01

    This report briefly discusses concepts of chaotic systems. The topics discusses are: Bernoulli maps; mathematical aspects of the complex spectral representations; and large poincare systems. (LSP)

  4. Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron microscopy

    DOE PAGES [OSTI]

    He, Kai; Zhang, Sen; Li, Jing; Yu, Xiqian; Meng, Qingping; Zhu, Yizhou; Hu, Enyuan; Sun, Ke; Yun, Hongseok; Yang, Xiao -Qing; et al

    2016-05-09

    In this study, spinel transition metal oxides are an important class of materials that are being considered as electrodes for lithium-ion batteries, due to their low cost and high theoretical capacity. The lithiation of these compounds is known to undergo a two-step reaction, whereby intercalation and conversion occur in a sequential fashion. These two reactions are known to have distinct reaction dynamics, but it is unclear how the kinetics of these processes affect the overall electrochemical response. Here, we explore the lithiation of nanosized magnetite (Fe3O4) by employing a new strain-sensitive, bright-field scanning transmission electron microscopy approach.

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

    SciTech Connect

    2010-09-01

    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.

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

    SciTech Connect

    DeMille, David; LeHur, Karyn

    2013-11-27

    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.

  7. A coupled implicit method for chemical non-equilibrium flows at all speeds

    SciTech Connect

    Shuen, J.S.; Choi, Y. ); Chen, K.H. )

    1993-06-01

    A time-accurate, coupled solution procedure is described for the chemical nonequilibrium Navier-Stokes equations over a wide range of Mach numbers. This method employs the strong conservation form of the governing equations, but uses primitive variables (p[sub g], u, v, h, Y[sub i]) as unknowns. Real gas properties and nonequilibrium chemistry are considered. Numerical tests include steady convergent-divergent nozzle flows with air dissociation/recombination chemistry, dump combustor flows with n-pentan air chemistry, and nonreacting unsteady driven cavity flows. Numerical results for both the steady and unsteady flows demonstrate the efficiency and robustness of the present algorithm for Mach numbers ranging from the incompressible limit to supersonic speeds. 26 refs., 10 figs.

  8. Tailoring of a metastable material: alfa-FeSi2 thin film

    DOE PAGES [OSTI]

    Cao, Guixin; Singh, David J; Zhang, Xiaoguang; Samolyuk, German D; Qiao, Liang; Parish, Chad M; Ke, Jin; Zhang, Yanwen; Guo, Hangwen; Wang, Wenbin; et al

    2015-01-01

    The epitaxially stabilized metallic -FeSi2 thin films on Si(001) were grown using pulsed laser deposition. While the bulk material of -FeSi2 is a high temperature metastable phase and nonmagnetic, the thin film is stabilized at room temperature and shows unusual electronic transport and magnetic properties due to strain modification. The transport renders two different conducting states with a strong crossover at 50 K accompanied by an onset of ferromagnetism as well as a substantial magnetocaloric effect and magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of -FeSi2 obtained within density functional calculations and Boltzmann transportmore » calculations with and without strain. Our findings provide an example of a tailored material with interesting physics properties for practical applications.« less

  9. Polarization-selective vortex-core switching by tailored orthogonal Gaussian-pulse currents

    SciTech Connect

    Jung, H.; Choi, Y. -S.; Yoo, M. -W.; Im, M. -Y.; Kim, S. -K.

    2010-10-13

    We experimentally demonstrate low-power-consumption vortex-core switching in magnetic nanodisks using tailored rotating magnetic fields produced with orthogonal and unipolar Gaussian-pulse currents. The optimal width of the orthogonal pulses and their time delay are found, from analytical and micromagnetic numerical calculations, to be determined only by the angular eigenfrequency {omega}{sub D} for a given vortex-state disk of polarization p, such that {sigma}=1/{omega}{sub D} and {Delta}t={pi}/2 p/{omega}{sub D} . The estimated optimal pulse parameters are in good agreement with the experimental results. This work lays a foundation for energy-efficient information recording in vortex-core cross-point architecture.

  10. Tailoring of unipolar strain in lead-free piezoelectrics using the ceramic/ceramic composite approach

    SciTech Connect

    Khansur, Neamul H.; Daniels, John E.; Groh, Claudia; Jo, Wook; Webber, Kyle G.; Reinhard, Christina; Kimpton, Justin A.

    2014-03-28

    The electric-field-induced strain response mechanism in a polycrystalline ceramic/ceramic composite of relaxor and ferroelectric materials has been studied using in situ high-energy x-ray diffraction. The addition of ferroelectric phase material in the relaxor matrix has produced a system where a small volume fraction behaves independently of the bulk under an applied electric field. Inter- and intra-grain models of the strain mechanism in the composite material consistent with the diffraction data have been proposed. The results show that such ceramic/ceramic composite microstructure has the potential for tailoring properties of future piezoelectric materials over a wider range than is possible in uniform compositions.

  11. Tailoring of a metastable material: alfa-FeSi2 thin film

    SciTech Connect

    Cao, Guixin; Singh, David J; Zhang, Xiaoguang; Samolyuk, German D; Qiao, Liang; Parish, Chad M; Ke, Jin; Zhang, Yanwen; Guo, Hangwen; Tang, Siwei; Wang, Wenbin; Yi, Jieyu; Cantoni, Claudia; Siemons, Wolter; Payzant, E Andrew; Biegalski, Michael D; Ward, Thomas Zac; Sales, Brian C; Mandrus, D.; Stocks, George Malcolm; Gai, Zheng

    2015-01-01

    The epitaxially stabilized metallic -FeSi2 thin films on Si(001) were grown using pulsed laser deposition. While the bulk material of -FeSi2 is a high temperature metastable phase and nonmagnetic, the thin film is stabilized at room temperature and shows unusual electronic transport and magnetic properties due to strain modification. The transport renders two different conducting states with a strong crossover at 50 K accompanied by an onset of ferromagnetism as well as a substantial magnetocaloric effect and magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of -FeSi2 obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our findings provide an example of a tailored material with interesting physics properties for practical applications.

  12. Layer thickness and period as design parameters to tailor pyroelectric properties in ferroelectric superlattices

    SciTech Connect

    Misirlioglu, I. B.; Alpay, S. P.

    2014-10-27

    We theoretically examine the pyroelectric properties of ferroelectric-paraelectric superlattices as a function of layer thickness and configuration using non-linear thermodynamics coupled with electrostatic and electromechanical interactions between layers. We specifically study PbZr{sub 0.3}Ti{sub 0.7}O{sub 3}/SrTiO{sub 3} superlattices. The pyroelectric properties of such constructs consisting of relatively thin repeating units are shown to exceed the pyroelectric response of monolithic PbZr{sub 0.3}Ti{sub 0.7}O{sub 3} films. This is related to periodic internal electric fields generated due to the polarization mismatch between layers that allows tailoring of the shift in the transition temperature. Our results indicate that higher and electric field sensitive pyroresponse can be achieved from layer-by-layer engineered ferroelectric heterostructures.

  13. Tailoring graphene magnetism by zigzag triangular holes: A first-principles thermodynamics study

    DOE PAGES [OSTI]

    Khan, Muhammad Ejaz; Zhang, P.; Sun, Yi -Yang; Zhang, S. B.; Kim, Yong -Hyun

    2016-03-30

    In this study, we discuss the thermodynamic stability and magnetic property of zigzag triangular holes (ZTHs) in graphene based on the results of first-principles density functional theory calculations. We find that ZTHs with hydrogen-passivated edges in mixed sp2/sp3 configurations (z211) could be readily available at experimental thermodynamic conditions, but ZTHs with 100% sp2 hydrogen-passivation (z1) could be limitedly available at high temperature and ultra-high vacuum conditions. Graphene magnetization near the ZTHs strongly depends on the type and the size of the triangles. While metallic z1 ZTHs exhibit characteristic edge magnetism due to the same-sublattice engineering, semiconducting z211 ZTHs do showmore » characteristic corner magnetism when the size is small < 2 nm. Our findings could be useful for experimentally tailoring metal-free carbon magnetism by simply fabricating triangular holes in graphene.« less

  14. Tailorable 3D microfabrication for photonic applications: two-polymer microtransfer molding (proceedings paper)

    SciTech Connect

    Lee, Jae-Hwang; kim, Chang-Hwan; Constant, Kristen; Ho, Kai-Ming

    2006-02-28

    For photonic devices, extending beyond the planar regime to the third dimension can allow a higher degree of integration and novel functionalities for applications such as photonic crystals and integrated optical circuits. Although conventional photolithography can achieve both high quality and structural control, it is still costly and slow for three-dimensional (3D) fabrication. Moreover, as diverse functional polymers emerge, there is potential to develop new techniques for quick and economical fabrication of 3D structures. We present a 3D microfabrication technique based on the soft lithographic technique, called two-polymer microtransfer molding (2P-{micro}TM) to accomplish low cost, high structural fidelity and tailorable 3D microfabrication for polymers. Using 2P-{micro}TM, highly layered polymeric microstructures are achievable by stacking planar structures layer by layer. For increased processing control, the surface chemistry of the polymers is characterized as a function of changing ultraviolet dosage to optimize yield in layer transfer. We discuss the application of the 2P-{micro}TM to build polymer templates for woodpile photonic crystals, and demonstrate methods for converting the polymer templates to dielectric and metallic photonic crystal structures. Finally, we will show that 2P-{micro}TM is promising for fabricating 3D polymeric optical waveguides.

  15. Epsilon-near-zero modes for tailored light-matter interaction

    DOE PAGES [OSTI]

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-20

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximizemore » the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.« less

  16. Tailoring Lignocelluloses for a Sustainable Energy Future (462nd Brookhaven Lecture)

    SciTech Connect

    Liu, Chang-Jun

    2010-10-21

    Today, the world relies on fossil fuels as a primary energy resource. This resource, however, is limited and associated with rising levels of carbon dioxide in the atmosphere. In consequence, the search for renewable biofuels has become increasingly vital. Solutions thus far have focused on first-generation biofuels, such as corn ethanol and biodiesel. But this is not enough. Chang-Jun Liu of the Biology Department discusses how he and his colleagues are studying a more abundant and environmentally friendly renewable energy source — lignocellulosic biomass — found in plant cell walls. Liu explaines, plant cell walls provide unlimited quantities of renewable biomass. However, the intertwined lignin and cellulose that make up the cell walls resist decomposition, so obtaining energy from cellulosic biomass is a challenge. Liu and his colleagues are exploring the biosynthesis and molecular regulation of plant cell walls, particularly that of the most formidable polymer — lignin. With this knowledge, they will develop novel strategies to tailor plant cell wall’s structure and composition for efficient biofuel and biomaterial production.

  17. Electrodeposition of InSb branched nanowires: Controlled growth with structurally tailored properties

    SciTech Connect

    Das, Suprem R.; Mohammad, Asaduzzaman; Janes, David B.; Akatay, Cem; Khan, Mohammad Ryyan; Alam, Muhammad A.; Maeda, Kosuke; Deacon, Russell S.; Ishibashi, Koji; Chen, Yong P.; Sands, Timothy D.

    2014-08-28

    In this article, electrodeposition method is used to demonstrate growth of InSb nanowire (NW) arrays with hierarchical branched structures and complex morphology at room temperature using an all-solution, catalyst-free technique. A gold coated, porous anodic alumina membrane provided the template for the branched NWs. The NWs have a hierarchical branched structure, with three nominal regions: a “trunk” (average diameter of 150 nm), large branches (average diameter of 100 nm), and small branches (average diameter of sub-10 nm to sub-20 nm). The structural properties of the branched NWs were studied using scanning transmission electron microscopy, transmission electron microscopy, scanning electron microscopy, x-ray diffraction, energy dispersive x-ray spectroscopy, and Raman spectroscopy. In the as-grown state, the small branches of InSb NWs were crystalline, but the trunk regions were mostly nanocrystalline with an amorphous boundary. Post-annealing of NWs at 420 °C in argon produced single crystalline structures along 〈311〉 directions for the branches and along 〈111〉 for the trunks. Based on the high crystallinity and tailored structure in this branched NW array, the effective refractive index allows us to achieve excellent antireflection properties signifying its technological usefulness for photon management and energy harvesting.

  18. Dry particle coating of polymer particles for tailor-made product properties

    SciTech Connect

    Blümel, C. Schmidt, J. Dielesen, A. Sachs, M. Winzer, B. Peukert, W. Wirth, K.-E.

    2014-05-15

    Disperse polymer powders with tailor-made particle properties are of increasing interest in industrial applications such as Selective Laser Beam Melting processes (SLM). This study focuses on dry particle coating processes to improve the conductivity of the insulating polymer powder in order to assemble conductive devices. Therefore PP particles were coated with Carbon Black nanoparticles in a dry particle coating process. This process was investigated in dependence of process time and mass fraction of Carbon Black. The conductivity of the functionalized powders was measured by impedance spectroscopy. It was found that there is a dependence of process time, respectively coating ratio and conductivity. The powder shows higher conductivities with increasing number of guest particles per host particle surface area, i.e. there is a correlation between surface functionalization density and conductivity. The assembled composite particles open new possibilities for processing distinct polymers such as PP in SLM process. The fundamentals of the dry particle coating process of PP host particles with Carbon Black guest particles as well as the influence on the electrical conductivity will be discussed.

  19. Tailoring the index of refraction of nanocrystalline hafnium oxide thin films

    SciTech Connect

    Vargas, Mirella; Murphy, N. R.; Ramana, C. V.

    2014-03-10

    Hafnium oxide (HfO{sub 2}) films were grown by sputter-deposition by varying the growth temperature (T{sub s} = 25–700 °C). HfO{sub 2} films grown at T{sub s} < 200 °C were amorphous, while those grown at T{sub s} ≥ 200 °C were monoclinic, nanocrystalline with (1{sup ¯}11) texturing. X-ray reflectivity (XRR) analyses indicate that the film-density (ρ) increases with increasing T{sub s}. The index of refraction (n) profiles derived from spectroscopic ellipsometry analyses follow the Cauchy dispersion relation. Lorentz-Lorenz analysis (n{sub (λ)} = 550 nm) and optical-model adopted agree well with the XRR data/analyses. A direct T{sub s}-ρ-n relationship suggests that tailoring the optical quality is possible by tuning T{sub s} and the microstructure of HfO{sub 2} films.

  20. In situ evaluation of several tailored-pulse well-shooting concepts

    SciTech Connect

    Schmidt, R A; Warpinski, N R; Cooper, P W

    1980-01-01

    This paper describes a series of five full-scale tests performed to evaluate various multi-frac concepts. The tests were conducted at the Nevada Test Site in cased, horizontal boreholes drilled in ash-fall tuff from a tunnel under 430 m of overburden. This site provides both realistic in situ conditions for the tests and access to the stimulated regions by mineback which permits direct observation of results. The five tailored-pulse concepts tested involve: Case A - a decoupled explosive, Case B - a decoupled explosive with propellant booster, Case C - a small-diameter propellant charge with pressurized water pad, Case D - three successive shots of Case C, and Case E - a full-diameter charge of a progressively-burning propellant. Results show a large increase in formation permeability for Case E, modest increases for Cases B, C, and D and a decrease for Case A that appears due to the formation of a stress cage. A comparison of Case E results with previous tests suggests a multiple fracture criterion based on pressure rate with little effect of peak pressures.

  1. Multipole and field uniformity tailoring of a 750 MHz rf dipole

    SciTech Connect

    Delayen, Jean R.; Castillo, Alejandro

    2014-12-01

    In recent years great interest has been shown in developing rf structures for beam separation, correction of geometrical degradation on luminosity, and diagnostic applications in both lepton and hadron machines. The rf dipole being a very promising one among all of them. The rf dipole has been tested and proven to have attractive properties that include high shunt impedance, low and balance surface fields, absence of lower order modes and far-spaced higher order modes that simplify their damping scheme. As well as to be a compact and versatile design in a considerable range of frequencies, its fairly simple geometry dependency is suitable both for fabrication and surface treatment. The rf dipole geometry can also be optimized for lowering multipacting risk and multipole tailoring to meet machine specific field uniformity tolerances. In the present work a survey of field uniformities, and multipole contents for a set of 750 MHz rf dipole designs is presented as both a qualitative and quantitative analysis of the inherent flexibility of the structure and its limitations.

  2. Epsilon-near-zero modes for tailored light-matter interaction

    SciTech Connect

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-20

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximize the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.

  3. Tailoring a low-molecular weight protein tyrosine phosphatase into an efficient reporting protein

    SciTech Connect

    Liu, Xiao-Yan; Li, Lan-Fen [The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Science, Peking University, Beijing 100871 (China)] [The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Science, Peking University, Beijing 100871 (China); Su, Xiao-Dong, E-mail: xdsu@pku.edu.cn [The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Science, Peking University, Beijing 100871 (China) [The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Science, Peking University, Beijing 100871 (China); Shenzhen Graduate School of Peking University, Shenzhen 518055 (China)

    2009-05-15

    Fusion reporter methods are important tools for biology and biotechnology. An ideal reporter protein in a fusion system should have little effects on its fusion partner and provide an easy and accurate readout. Therefore, a small monomeric protein with high activity for detection assays often has advantages as a reporter protein. For this purpose, we have tailored the human B-form low-molecular-weight phosphotyrosyl phosphatase (HPTP-B) to increase its general applicability as a potent reporter protein. With the aim to eliminate interference from cysteine residues in the native HPTP-B, combined with a systematic survey of N- and C-terminal truncated variants, a series of cysteine to serine mutations were introduced, which allowed isolation of an engineered soluble protein with suitable biophysical properties. When we deleted both the first six residues and the last two residues, we still obtained a soluble mutant protein with correct folding and similar activity with wild-type protein. This mutant with two cysteine to serine mutations, HPTP-B{sup N{sub {Delta}}6-C{sub {Delta}}2-C90S-C109S}, has good potential as an optimal reporter.

  4. Passive tailoring of laser-accelerated ion beam cut-off energy by using double foil assembly

    SciTech Connect

    Chen, S. N. Brambrink, E.; Mancic, A.; Romagnani, L.; Audebert, P.; Fuchs, J.; Robinson, A. P. L.; Antici, P.; Dipartimento SBAI, Università di Roma « La Sapienza », Via Scarpa 14-16, 00165 Roma; INRS-Énergie et Matériaux, 1650 bd. L. Boulet, Varennes, J3X1S2 Québec ; D'Humières, E.; Centre de Physique Théorique, CNRS-Ecole Polytechnique, 91128 Palaiseau; University of Bordeaux—CNRS—CEA, CELIA, UMR5107, 33405 Talence ; Gaillard, S.; Grismayer, T.; Mora, P.; Pépin, H.

    2014-02-15

    A double foil assembly is shown to be effective in tailoring the maximum energy produced by a laser-accelerated proton beam. The measurements compare favorably with adiabatic expansion simulations, and particle-in-cell simulations. The arrangement proposed here offers for some applications a simple and passive way to utilize simultaneously highest irradiance lasers that have best laser-to-ion conversion efficiency while avoiding the production of undesired high-energy ions.

  5. Facile synthesis of B-type carbonated nanoapatite with tailored microstructure

    SciTech Connect

    Gualtieri, Magdalena Lassinantti; Romagnoli, Marcello; Hanuskova, Miriam; Fabbri, Elena; Gualtieri, Alessandro F.

    2014-12-15

    Nanolime and a phosphate-based chelating agent were used to synthesize B-type carbonated apatite. Developed Rietveld refinement strategies allowed one to determine process yield, product crystallinity as well as structural (unit cell) and microstructural (size, strain) parameters. The effect of synthesis temperature (20–60 °C) as well as Ca/P ratio (1.5–2.5) and solid content (10–30 wt%) of the starting batch on these properties were investigated. FTIR, TEM and gas adsorption data provided supporting evidence. The process yield was 42–60 wt% and found to be governed by the Ca/P ratio. The purified products had high specific surface area (107–186 m{sup 2}/g) and crystallinity (76–97%). The unit cell parameters, correlated to the degree of structural carbonate, were sensitive to the Ca/P ratio. Instead, temperature governed the microstructural parameters. Less strained and larger crystals were obtained at higher temperatures. Long-term aging up to 6 months at 20 °C compensated for higher crystal growth kinetics at higher temperature. - Graphical abstract: Controlled synthesis of carbonated apatite at moderate temperatures using nanolime and sodiumhexametaphosphate as starting reagent. - Highlights: • Chemical synthesis of nano-sized apatite with tailored microstructure was performed. • Colloidal Ca(OH){sub 2} and a phosphorus-based chelating agents were used as reagents. • The method is simple and reproducible which facilitate industrial process scale-up. • Rietveld refinement strategies for product characterization were developed. • Rietveld analyses provided yield, microstructural and structure information.

  6. Oxygen and relative humidity monitoring with films tailored for enhanced photoluminescence

    DOE PAGES [OSTI]

    Cui, Weipan; Liu, Rui; Manna, Eeshita; Park, Joong -Mok; Fungura, Fadzai; Shinar, Joseph; Shinar, Ruth

    2014-10-31

    In this study, approaches to generate porous or doped sensing films, which significantly enhance the photoluminescence (PL) of oxygen optical sensors, and thus improve the signal-to-noise (S/N) ratio, are presented. Tailored films, which enable monitoring the relative humidity (RH) as well, are also presented. Effective porous structures, in which the O2-sensitive dye Pt octaethylporphyrin (PtOEP) or the Pd analog PdOEP was embedded, were realized by first generating blend films of polyethylene glycol (PEG) with polystyrene (PS) or with ethyl cellulose (EC), and then immersing the dried films in water to remove the water-soluble PEG. This approach creates pores (voids) inmore » the sensing films. The dielectric contrast between the films’ constituents and the voids increases photon scattering, which in turn increases the optical path of the excitation light within the film, and hence light absorption by the dye, and its PL. Optimized sensing films with a PEG:PS ratio of 1:4 (PEG’s molecular weight Mw ~8000) led to ~4.4× enhancement in the PL (in comparison to PS films). Lower Mw ~200 PEG with a PEG:EC ratio of 1:1 led to a PL enhancement of ~4.7×. Film-dependent PL enhancements were observed at all oxygen concentrations. The strong PL enhancement enables (i) using lower dye (luminophore) concentrations, (ii) reducing power consumption and enhancing the sensor’s operational lifetime when using organic light emitting diodes (OLEDs) as excitation sources, (iii) improving performance when using compact photodetectors with no internal gain, and (iv) reliably extending the dynamic range.« less

  7. AN ANALYTICAL MODEL OF INTERSTELLAR GAS IN THE HELIOSPHERE TAILORED TO INTERSTELLAR BOUNDARY EXPLORER OBSERVATIONS

    SciTech Connect

    Lee, Martin A.; Kucharek, Harald; Moebius, Eberhard; Wu Xian [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Bzowski, Maciej [Space Research Centre, Polish Academy of Sciences, 00-716 Warsaw (Poland); McComas, David, E-mail: marty.lee@unh.edu [Engineering and Space Science Division, Southwest Research Institute, San Antonio, TX 78228 (United States)

    2012-02-01

    The stationary distribution of interstellar neutral gas in the heliosphere subject to solar gravity, solar radiation pressure, photoionization, and charge exchange is investigated analytically assuming ionization rates and radiation pressure that are proportional to R{sup -2}, where R is the heliocentric radius. The collisionless hyperbolic trajectories of the individual atoms including ionization losses are combined with Liouville's Theorem to construct the heliospheric phase-space distribution function of an interstellar gas species in the solar reference frame under the assumption that the distribution is a drifting Maxwellian at large distances from the Sun. The distribution is transformed to the Earth (essentially Interstellar Boundary Explorer (IBEX)) frame as a function of solar longitude. The expression is then tailored to the latitudinal scan of IBEX as a function of longitude using the fact that IBEX detects each atom close to perihelion in its hyperbolic orbit. The distribution is further adapted to IBEX by integrating the differential intensity over the entrance aperture solid angle of the IBEX-Lo collimator, and over energy to predict the IBEX count rate of helium. The major features of the predicted count rate are described, including a peak in longitude, a peak in latitude at each longitude, and the widths of the major peak in both latitude and longitude. Analytical formulae for these features are derived for comparison with IBEX observations in order to determine the temperature and bulk velocity of the gas in interstellar space. Based in part on these formulae, the results for helium are presented in the companion paper by Moebius et al.

  8. Towards tailoring the magnetocaloric response in FeRh-based ternary compounds

    SciTech Connect

    Barua, Radhika Jiménez-Villacorta, Félix; Lewis, L. H.

    2014-05-07

    In this work, we demonstrate that the magnetocaloric response of FeRh-based compounds may be tailored for potential magnetic refrigeration applications by chemical modification of the FeRh lattice. Alloys of composition Fe(Rh{sub 1−x}A{sub x}) or (Fe{sub 1−x}B{sub x})Rh (A = Cu, Pd; B = Ni; 0 < x < 0.06) were synthesized via arc-melting and subsequent annealing in vacuum at 1000 °C for 48 h. The magnetocaloric properties of the FeRh-based systems were determined using isothermal M(H) curves measured in the vicinity of the magnetostructural temperature (T{sub t}). It is found that the FeRh working temperature range (δT{sub FWHM}) may be chemically tuned over a wide temperature range, 100 K ≤ T ≤ 400 K. While elemental substitution consistently decreases the magnetic entropy change (ΔS{sub mag}) of the FeRh-based ternary alloys from that of the parent FeRh compound (ΔS{sub mag},{sub FeRh} ∼ 17 J/kg K; ΔS{sub mag,FeRh-ternary =} 7–14 J/kg K at H{sub app} = 2 T), the net refrigeration capacity (RC), defined as the amount of heat that can be transferred during one magnetic refrigeration cycle, of the modified systems is significantly higher (RC{sub FeRh} ∼ 150 J/kg; RC{sub FeRh-ternary =} 170–210 J/kg at H{sub app} = 2 T). These results are attributed to stoichiometry-induced changes in the FeRh electronic band structure and beneficial broadening of the magnetostructural transition due to local chemical disorder.

  9. Controlling the spectrum of x-rays generated in a laser-plasma accelerator by tailoring the laser wavefront

    SciTech Connect

    Mangles, S. P. D.; Kneip, S.; Dover, N. P.; Najmudin, Z.; Schreiber, J.; Genoud, G.; Burza, M.; Kamperidis, C.; Persson, A.; Wahlstroem, C.-G.; Cassou, K.; Cros, B.; Wojda, F.

    2009-11-02

    By tailoring the wavefront of the laser pulse used in a laser-wakefield accelerator, we show that the properties of the x-rays produced due to the electron beam's betatron oscillations in the plasma can be controlled. By creating a wavefront with coma, we find that the critical energy of the synchrotronlike x-ray spectrum can be significantly increased. The coma does not substantially change the energy of the electron beam, but does increase its divergence and produces an energy-dependent exit angle, indicating that changes in the x-ray spectrum are due to an increase in the electron beam's oscillation amplitude within the wakefield.

  10. Design and Testing of a 10B4C Capsule for Spectral-Tailoring in Mixed-Spectrum Reactors

    SciTech Connect

    Greenwood, Lawrence R.; Wittman, Richard S.; Metz, Lori A.; Finn, Erin C.; Friese, Judah I.

    2014-04-11

    A boron carbide capsule highly enriched in 10B has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. New experiments show that enriching the boron to 96% B-10 results in additional absorption of neutrons in the resonance region thereby producing a neutron spectrum that is much closer to a pure 235U fission spectrum. A cadmium outer cover was used to reduce thermal heating. The neutron spectrum calculated with MCNP was found to be in very good agreement with measured activation rates from neutron fluence monitors.

  11. Rapid production of large-area deep sub-wavelength hybrid structures by femtosecond laser light-field tailoring

    SciTech Connect

    Wang, Lei; Chen, Qi-Dai E-mail: hbsun@jlu.edu.cn; Yang, Rui; Xu, Bin-Bin; Wang, Hai-Yu; Yang, Hai; Huo, Cheng-Song; Tu, Hai-Ling; Sun, Hong-Bo E-mail: hbsun@jlu.edu.cn

    2014-01-20

    The goal of creation of large-area deep sub-wavelength nanostructures by femtosecond laser irradiation onto various materials is being hindered by the limited coherence length. Here, we report solution of the problem by light field tailoring of the incident beam with a phase mask, which serves generation of wavelets. Direct interference between the wavelets, here the first-order diffracted beams, and interference between a wavelet and its induced waves such as surface plasmon polariton are responsible for creation of microgratings and superimposed nanogratings, respectively. The principle of wavelets interference enables extension of uniformly induced hybrid structures containing deep sub-wavelength nanofeatures to macro-dimension.

  12. Chemistry of SOFC Cathode Surfaces: Fundamental Investigation and Tailoring of Electronic Behavior

    SciTech Connect

    Yildiz, Bilge; Heski, Clemens

    2013-08-31

    provides a predictive capability to tailor the cathode surface compositions for high-performance SO

  13. Mechanism of tailored magnetic anisotropy in amorphous Co{sub 68}Fe{sub 24}Zr{sub 8} thin films

    SciTech Connect

    Fu, Yu E-mail: cangcangzhulin@gmail.com; Meckenstock, R.; Farle, M.; Barsukov, I.; Lindner, J.; Raanaei, H.; Hjörvarsson, B.

    2014-02-17

    The mechanism of tailored magnetic anisotropy in amorphous Co{sub 68}Fe{sub 24}Zr{sub 8} thin films was investigated by ferromagnetic resonance (FMR) on samples deposited without an applied magnetic field, with an out-of-plane field and an in-plane field. Analysis of FMR spectra profiles, high frequency susceptibility calculations, and statistical simulations using a distribution of local uniaxial magnetic anisotropy reveal the presence of atomic configurations with local uniaxial anisotropy, of which the direction can be tailored while the magnitude remains at an intrinsically constant value of 3.0(2) kJ/m{sup 3}. The in-plane growth field remarkably sharpens the anisotropy distribution and increases the sample homogeneity. The results benefit designing multilayer spintronic devices based on highly homogeneous amorphous layers with tailored magnetic anisotropy.

  14. Non-Equilibrium Vibrational Kinetics in Radiofrequency H2 Plasmas: a Comparison Between Theoretical and Experimental Results

    SciTech Connect

    Capitelli, M.; De Pascale, O.; Shakatov, V.; Hassouni, K.; Lombardi, G.; Gicquel, A.

    2005-05-16

    Vibrational and rotational experimental temperatures of molecular hydrogen obtained by Coherent Anti-Stokes Spectroscopy (CARS) in Radiofrequency Inductive Plasmas have been analyzed and interpreted in terms of vibration, electron, dissociation-recombination and attachment kinetics. The analysis clarifies the role of atomic hydrogen and its heterogeneous recombination in affecting the vibrational content of the molecules.

  15. Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses

    SciTech Connect

    Canton, Sophie E.; Kjr, Kasper S.; Vank, Gyrgy; van Driel, Tim B.; Adachi, Shin -ichi; Bordage, Amlie; Bressler, Christian; Chabera, Pavel; Christensen, Morten; Dohn, Asmus O.; Galler, Andreas; Gawelda, Wojciech; Gosztola, David; Haldrup, Kristoffer; Harlang, Tobias; Liu, Yizhu; Mller, Klaus B.; Nmeth, Zoltn; Nozawa, Shunsuke; Ppai, Mtys; Sato, Tokushi; Sato, Takahiro; Suarez-Alcantara, Karina; Togashi, Tadashi; Tono, Kensuke; Uhlig, Jens; Vithanage, Dimali A.; Wrnmark, Kenneth; Yabashi, Makina; Zhang, Jianxin; Sundstrm, Villy; Nielsen, Martin M.

    2015-03-02

    Ultrafast photoinduced electron transfer preceding energy equilibration still poses many experimental and conceptual challenges to the optimization of photoconversion since an atomic-scale description has so far been beyond reach. Here we combine femtosecond transient optical absorption spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donoracceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution as compared with storage ring facilities, these measurements constitute the first X-ray-based visualization of a non-equilibrated intramolecular electron transfer process over large interatomic distances. Thus experimental and theoretical results establish that mediation through electronically excited molecular states is a key mechanistic feature. The present study demonstrates the extensive potential of femtosecond X-ray techniques as diagnostics of non-adiabatic electron transfer processes in synthetic and biological systems, and some directions for future studies, are outlined.

  16. Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses

    DOE PAGES [OSTI]

    Canton, Sophie E.; Kjær, Kasper S.; Vankó, György; van Driel, Tim B.; Adachi, Shin -ichi; Bordage, Amélie; Bressler, Christian; Chabera, Pavel; Christensen, Morten; Dohn, Asmus O.; et al

    2015-03-02

    Ultrafast photoinduced electron transfer preceding energy equilibration still poses many experimental and conceptual challenges to the optimization of photoconversion since an atomic-scale description has so far been beyond reach. Here we combine femtosecond transient optical absorption spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donor–acceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution as compared with storage ring facilities, these measurements constitute the first X-ray-based visualization of a non-equilibrated intramolecular electron transfer process over large interatomic distances.more » Thus experimental and theoretical results establish that mediation through electronically excited molecular states is a key mechanistic feature. The present study demonstrates the extensive potential of femtosecond X-ray techniques as diagnostics of non-adiabatic electron transfer processes in synthetic and biological systems, and some directions for future studies, are outlined.« less

  17. Tailoring the laser pulse shape to improve the quality of the self-injected electron beam in laser wakefield acceleration

    SciTech Connect

    Upadhyay, Ajay K.; Samant, Sushil A.; Krishnagopal, S.

    2013-01-15

    In laser wakefield acceleration, tailoring the shape of the laser pulse is one way of influencing the laser-plasma interaction and, therefore, of improving the quality of the self-injected electron beam in the bubble regime. Using three-dimensional particle-in-cell simulations, the evolution dynamics of the laser pulse and the quality of the self-injected beam, for a Gaussian pulse, a positive skew pulse (i.e., one with sharp rise and slow fall), and a negative skew pulse (i.e., one with a slow rise and sharp fall) are studied. It is observed that with a negative skew laser pulse there is a substantial improvement in the emittance (by around a factor of two), and a modest improvement in the energy-spread, compared to Gaussian as well as positive skew pulses. However, the injected charge is less in the negative skew pulse compared to the other two. It is also found that there is an optimal propagation distance that gives the best beam quality; beyond this distance, though the energy increases, the beam quality deteriorates, but this deterioration is least for the negative skew pulse. Thus, the negative skew pulse gives an improvement in terms of beam quality (emittance and energy spread) over what one can get with a Gaussian or positive skew pulse. In part, this is because of the lesser injected charge, and the strong suppression of continuous injection for the negative skew pulse.

  18. Tailored Recovery of Carbons from Waste Tires for Enhanced Performance as Anodes in Lithium-ion Batteries

    SciTech Connect

    Naskar, Amit K; Bi,; Saha, Dipendu; Chi, Miaofang; Bridges, Craig A; Paranthaman, Mariappan Parans

    2014-01-01

    Morphologically tailored pyrolysis-recovered carbon black is utilized in lithium-ion batteries as a potential solution for adding value to waste tire-rubber-derived materials. Micronized tire rubber was digested in a hot oleum bath to yield a sulfonated rubber slurry that was then filtered, washed, and compressed into a solid cake. Carbon was recovered from the modified rubber cake by pyrolysis in a nitrogen atmosphere. The chemical pretreatment of rubber produced a carbon monolith with higher yield than that from the control (a fluffy tire-rubber-derived carbon black). The carbon monolith showed a very small volume fraction of pores of widths 3 4 nm, reduced specific surface area, and an ordered assembly of graphitic domains. Electrochemical studies on the recovered-carbon-based anode revealed an improved Li-ion battery performance with higher reversible capacity than that of commercial carbon materials. Anodes made with a sulfonated tire-rubber-derived carbon and a control tire-rubber-derived carbon, respectively, exhibited an initial coulombic efficiency of 80% and 45%, respectively. The reversible capacity of the cell with the sulfonated carbon as anode was 400 mAh/g after 100 cycles, with nearly 100% coulombic efficiency. Our success in producing higher performance carbon material from waste tire rubber for potential use in energy storage applications adds a new avenue to tire rubber recycling.

  19. Tailoring the magnetic properties of new Fe-Ni-Co-Al-(Ta,Nb)-B superelastic rapidly quenched microwires

    SciTech Connect

    Borza, F. Lupu, N.; Dobrea, V.; Chiriac, H.

    2015-05-07

    Ferromagnetic Fe-Ni-Co-Al-(Ta,Nb)-B microwires with diameters from 170 μm to 50 μm, which possess both superelastic and good magnetic properties, have been prepared by rapid quenching from the melt using the in rotating water spinning technique followed by cold-drawing and ageing. The cold-drawing and annealing processes lead to the initialization of premartensitic phases as confirmed by the X-ray diffraction and scanning transmission electron microscopic investigations, more significantly in the 50 μm cold-drawn microwires. An increase in the coercive field and in the saturation magnetization has been obtained by annealing, more importantly in the case of Nb-containing alloy. Ageing by thermal or current annealing led to the initialization of the superelastic effect. High values of strain of up to 1.8%, very good repeatability under successive loading, and values of superelastic effect of up to 1.2% have been achieved. The structural analysis coupled with the stress-strain data suggests that these materials annealed at 800 °C have superelastic potential at reduced ageing times. The magnetic behavior was found to be easily tailored through both thermal and thermomagnetic treatments with changes in the magnetic parameters which can be contactless detected. The results are important for future applications where both mechanical and magnetic properties matter, i.e., sensing/actuating systems.

  20. Role of bimodal distribution in tailoring the inter-particle interactions in Cu{sub 79}Co{sub 21} nanogranular films

    SciTech Connect

    Kumar, Dinesh Chaudhary, Sujeet Pandya, Dinesh K.

    2014-04-24

    Nanogranular Cu{sub 79}Co{sub 21} films were deposited by magnetron co-sputtering and their magnetotransport properties were investigated as a function of thickness (t). The fitting of magnetoresistance (MR) data reveals the presence of bimodal distribution of Co-particles. With the increase of film thickness from 25 to 200 nm, whereas smaller particle (2.5 nm) distribution remains unaffected, the bigger one grows monotonically from 3.3 nm to 4.9 nm for 25 ≤ t < 100 nm and stays same (4.9 nm) for 100 ≤ t ≤ 200 nm. From MR data recorded in the range of 20–300 K, it is observed that dependence of MR on thickness keeps on reducing on lowering the temperature. This observance has been presented in terms of presence of bimodal distribution and its role in tailoring the inter-particle magnetic interactions.

  1. Single crystalline Pr{sub 2-x}Y{sub x}O{sub 3} (x=0-2) dielectrics on Si with tailored electronic and crystallographic structure

    SciTech Connect

    Seifarth, O.; Schubert, M. A.; Giussani, A.; Schroeder, T.; Klenov, D. O.; Schmeisser, D.

    2010-11-15

    Crystalline oxides on Si with tailored electronic and crystallographic properties are of importance for the integration of functional oxides or alternative semiconductors to enable novel device concepts in Si microelectronics. We present an electronic band gap study of single crystalline Pr{sub 2-x}Y{sub x}O{sub 3} (0{<=}x{<=}2) heterostructures on Si(111). The perfect solubility of the isomorphic bixbyites Pr{sub 2}O{sub 3} and Y{sub 2}O{sub 3} during molecular beam epitaxy thin film growth on Si enables a linear band gap tuning. Special focus is devoted to the determination of the electronic band offsets across the dielectric/Si interface. In addition, the composition x allows to control the crystallographic lattice parameter where, for example, Pr{sub 0.8}Y{sub 1.2}O{sub 3} enables the growth of fully lattice matched oxide heterostructures on Si.

  2. A general unified non-equilibrium model for predicting saturated and subcooled critical two-phase flow rates through short and long tubes

    SciTech Connect

    Fraser, D.W.H.; Abdelmessih, A.H.

    1995-09-01

    A general unified model is developed to predict one-component critical two-phase pipe flow. Modelling of the two-phase flow is accomplished by describing the evolution of the flow between the location of flashing inception and the exit (critical) plane. The model approximates the nonequilibrium phase change process via thermodynamic equilibrium paths. Included are the relative effects of varying the location of flashing inception, pipe geometry, fluid properties and length to diameter ratio. The model predicts that a range of critical mass fluxes exist and is bound by a maximum and minimum value for a given thermodynamic state. This range is more pronounced at lower subcooled stagnation states and can be attributed to the variation in the location of flashing inception. The model is based on the results of an experimental study of the critical two-phase flow of saturated and subcooled water through long tubes. In that study, the location of flashing inception was accurately controlled and adjusted through the use of a new device. The data obtained revealed that for fixed stagnation conditions, the maximum critical mass flux occurred with flashing inception located near the pipe exit; while minimum critical mass fluxes occurred with the flashing front located further upstream. Available data since 1970 for both short and long tubes over a wide range of conditions are compared with the model predictions. This includes test section L/D ratios from 25 to 300 and covers a temperature and pressure range of 110 to 280{degrees}C and 0.16 to 6.9 MPa. respectively. The predicted maximum and minimum critical mass fluxes show an excellent agreement with the range observed in the experimental data.

  3. Non-equilibrium synthesis by laser cladding of Ni, Nb and Mg alloys for improved environmental resistance. Final report, Nov 88-Oct 91

    SciTech Connect

    Mazumder, J.; Kar, A.; Tewari, S.K.; Ribaudo, C.R.

    1992-03-30

    The technique of laser surface modification provides a unique means of synthesizing novel nonequilibrium materials in near net shape. The goal of the proposed program is to develop a science base for synthesis of nonequilibrium metastable alloys by laser processing. This report summarizes experimental and theoretical studies carried out during the period of November 1988 to October 1991 on laser surface modification of Ni, Nb and Mg alloys for improved environmental resistance at high temperature. A microstructural evolution model of NbAl3 was developed and the relative oxidation resistance of claddings of several Nb-based alloys were investigated. Initial work with V revealed that V increases the ductility, and decreases the oxidation resistance of laser clad NbAl3. Oxidation behavior of alloys with Ti, B and Hf as a ternary alloy addition were identified: Oxidation tests at 800, 1200, and 1400 deg C were conducted on NbAl3-0 at %B (O B), NbAl3-0.5 at %B (0.5 B), NbAl3-1.0 at %B (1.0 B), NbAl3-1.0 at B-3 at %Ti (3 Ti), NbAl3-1.0 at %B-6 at %Ti (6 Ti) and NbAl3-1.5 at %Hf (1.5 Hf) alloys. An external layer of x-alumina formed on samples of alloys 0.5 B and 1.0 B isothermally oxidized in air at 800, 1200 and 1400 deg C. A mixture of alumina and NbAl04 formed on the samples of alloy 0 B exposed to same testing conditions.

  4. The behavior of matter under non-equilibrium conditions: Fundamental aspects and applications. Progress report, July 15, 1991--July 14, 1992

    SciTech Connect

    Prigogine, I.

    1992-04-01

    This report briefly discusses concepts of chaotic systems. The topics discusses are: Bernoulli maps; mathematical aspects of the complex spectral representations; and large poincare systems. (LSP)

  5. Modeling of ground water aquifer remediation by pulsed pumping when contaminant transport is affected by physical, non-equilibrium sorption and desorption. Master's thesis

    SciTech Connect

    Caspers, J.L.

    1994-08-12

    This research postulates and demonstrates incorporating rate-limited sorption effects in the USGS SUTRA code for cleanup of a hypothetical sandy aquifer by pump-and-treat remediation methods. Contaminant transport is assumed to be affected by advection, dispersion, and rate-limited sorption/desorption. Sorption is assumed to be either equilibrium or rate-limited, with the rate-limitation described by either a first-order law, or by Fickian diffusion of contaminant through a spherical immobile pore region. Solutions are arrived at by split operator methods for the transport and one-dimensional Galerkin solutions for the solute concentration equations. The resulting model is tested against an analytical Laplace transform model for both first-order and Fickian diffusion methods in a radial pumping simulation. Model simulations are used to evaluate equilibrium, first-order and Fickian diffusion effects for pulsed and continuous pumping solutions within a hypothetical sandy aquifer. These show that equilibrium methods under-predicted rebound while first-order methods may both under and over predict rebound within the matrix for certain regions and may be equivalent to Fickian diffusion in equilibrium regimes for cleanup time prediction. Model simulations are then used to show the efficiency of pulsed pumping methods in cleanup mass extraction per pumped volume for a contaminated aquifer pump-and-treat remediation activity versus more conventional, continuous pumping methods.

  6. Simultaneous enhancement of carrier mobility and concentration via tailoring of Al-chemical states in Al-ZnO thin films

    SciTech Connect

    Kumar, Manish Wen, Long; Sahu, Bibhuti B.; Han, Jeon Geon

    2015-06-15

    Simultaneously achieving higher carriers concentration and mobility is a technical challenge against up-scaling the transparent-conductive performances of transparent-conductive oxides. Utilizing one order higher dense (∼1 × 10{sup 11} cm{sup −3}) plasmas (in comparison to the conventional direct current plasmas), highly c-axis oriented Al-doped ZnO films have been prepared with precise control over relative composition and chemical states of constituting elements. Tailoring of intrinsic (O vacancies) and extrinsic (ionic Al and zero-valent Al) dopants provide simultaneous enhancement in mobility and concentration of charge carriers. Room-temperature resistivity as low as 4.89 × 10{sup −4} Ω cm along the carrier concentration 5.6 × 10{sup 20} cm{sup −3} is obtained in 200 nm thick transparent films. Here, the control of atomic Al reduces the charge trapping at grain boundaries and subdues the effects of grain boundary scattering. A mechanism based on the correlation between electron-hole interaction and carrier mobility is proposed for degenerately doped wide band-gap semiconductors.

  7. Neutron dosimetry, damage calculations, and helium measurements for the HFIR-MFE-60J-1 and MFE-330J-1 spectral tailoring experiments

    SciTech Connect

    Greenwood, L.R.; Baldwin, C.A.; Oliver, B.M.

    1995-04-01

    The objective is to provide dosimetry and damage analysis for fusion materials irradiation experiments. Neutron fluence measurements and radiation damage calculations are reported for the joint US -Japanese MFE-60J-1 and MFE-330J-1 experiments in the hafnium-lined removable beryllium (RB{sup *}) position of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. These experiments were continuations of the ORR-6J and 7J irradiations performed in the Oak Ridge Research Reactor. The combination of irradiations was designed to tailor the neutron spectrum in order to achieve fusion reactor helium/dpa levels in stainless steel. These experiments produced maximum helium (appm)/dpa(displacement per atom) levels of 10.2 at 18.5 dpa for the ORR-6J and HFIR-MFE-60J-1 combination and 11.8 at 19.0 dpa for the ORR-7J and HFIR-MFE-330J-1 combination. A helium measurement in one JPCA sample was in good agreement with helium calculations.

  8. Small-scale experiments with an analysis to evaluate the effect of tailored pulse loading on fracture and permeability. Final report for phase I, June 11, 1979-June 11, 1980

    SciTech Connect

    McHugh, S.

    1980-06-01

    To determine the applicability of the tailored pulse-loading technique to full-scale stimulation, a two-year program was conducted to examine the effects of pulse tailoring on fracture. Results of the field, laboratory, and calculational program demonstrate that: (1) the material and fracture properties derived from laboratory measurements can be used successfully in the NAG-FRAG calculational simulations to reproduce the main features of fracturing in the field; and (2) the fracture patterns produced in these experiments show a strong dependence on the borehole pressure pulse shape. The material and fracture properties will have a significant influence on the fracture patterns. Therefore, shale and tuff will have different optimum pulse shapes.

  9. Novel chemically stable Ba3Ca1.18Nb1.82-xYxO9- proton conductor: improved proton conductivity through tailored cation ordering

    SciTech Connect

    Wang, Siwei; Chen, Yan; Fang, Shumin; Zhang, Lingling; Tang, Ming; An, Ke; Brinkman, Dr. Kyle S.; Chen, Fanglin

    2014-01-01

    Simple perovskite-structured proton conductors encounter significant challenges to simultaneously achieving excellent chemical stability and proton conductivity that are desirable for many important applications in energy conversion and storage. This work demonstrates that Y-doped complex-perovskite-structured Ba3Ca1.18Nb1.82 xYxO9 materials possess both improved proton conductivity and exceptional chemical stability. Neutron powder diffraction refinement revealed a Fm3 m perovskite-structure and increased oxygen vacancy concentration due to the Y doping. High-resolution TEM analysis confirmed the perturbation of the B site cation ordering in the structure for the Ba3Ca1.18Nb1.82 xYxO9 materials. Such combined effects led to improved proton conductivity with a value of 5.3 10 3 S cm 1 at 600 C for Ba3Ca1.18Nb1.52Y0.3O9 (BCNY0.3), a value 2.4 times higher compared with that of the undoped Ba3Ca1.18Nb1.82O9 . The Ba3Ca1.18Nb1.82 xYxO9 materials showed remarkable chemical stability toward water and demonstrated no observable reactions to CO2 exposure. Ionic transport number studies showed that BCNY0.3 had predominantly proton conduction below 600 C. Solid oxide fuel cells using BCNY0.3 as an electrolyte demonstrated cell power output of 103 mW cm 2 at 750 C. These results suggest that a doping strategy that tailors the cation ordering in complex perovskites provides a new direction in the search for novel proton conducting ceramics.

  10. A MATERIAL WORLD Tailoring Materials

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Sandia's newly developed information-extraction software. ... Sandia has broad- based research and development ... of Sandia's photovoltaic water-pumping station on Rancho ...

  11. Tailoring nanocrystalline diamond film properties

    DOEpatents

    Gruen, Dieter M.; McCauley, Thomas G.; Zhou, Dan; Krauss, Alan R.

    2003-07-15

    A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

  12. SiO{sub 2} nanospheres with tailorable interiors by directly controlling Zn{sup 2+} and NH{sub 3}.H{sub 2}O species in an emulsion process

    SciTech Connect

    Liao Yuchao; Wu Xiaofeng; Wang Zhen; Chen Yunfa

    2011-07-15

    SiO{sub 2} nanospheres with tailorable interiors were synthesized by a facile one-spot microemulsion process using TEOS as silica source, wherein cyclohexane including triton X-100 and n-octanol as oil phase and Zn{sup 2+} or NH{sub 3}.H{sub 2}O aqueous solution as dispersive phase, respectively. The products were characterized by Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray Powder Diffraction. It was suggested that the as-synthesized silica nanospheres possessed grape-stone-like porous or single hollow interior, and also found that the ammonia dosage and aging time played key roles in controlling the size and structure of silica nanospheres. Furthermore, the comparative results confirmed that in-situ zinc species [ZnO/Zn(OH){sub 2}] acted as the temporary templates to construct grape-stone-like interior, and a simultaneously competing etching process occurred owing to the soluble Zn(NH{sub 3}){sub 4}{sup 2+} complex formation while the additional excessive ammonia was introduced. With the aging time being extended, the in-situ nanocrystals tended to grow into bigger ones by Ostwald Ripening, producing single hollow interior. - Graphical Abstract: Formation process of SiO{sub 2} nanospheres with porous and single hollow interior. Highlights: > ZnO/Zn(OH){sub 2} nanocrystals as the temporary templates shape the interior structures of SiO{sub 2} nanospheres. > Fabrication of porous and single hollow interiors needs no additional processes such as roasting or dissolving. > Tailorable interiors can be easily obtained through adjusting the aging time of temporary templates.

  13. ?Linear Gas Jet with Tailored Density Profile"

    SciTech Connect

    KRISHNAN, Mahadevan

    2012-12-10

    Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

  14. Tailored ion energy distributions on plasma electrodes

    SciTech Connect

    Economou, Demetre J.

    2013-09-15

    As microelectronic device features continue to shrink approaching atomic dimensions, control of the ion energy distribution on the substrate during plasma etching and deposition becomes increasingly critical. The ion energy should be high enough to drive ion-assisted etching, but not too high to cause substrate damage or loss of selectivity. In many cases, a nearly monoenergetic ion energy distribution (IED) is desired to achieve highly selective etching. In this work, the author briefly reviews: (1) the fundamentals of development of the ion energy distribution in the sheath and (2) methods to control the IED on plasma electrodes. Such methods include the application of “tailored” voltage waveforms on an electrode in continuous wave plasmas, or the application of synchronous bias on a “boundary electrode” during a specified time window in the afterglow of pulsed plasmas.

  15. Tailored fischer-tropsch synthesis product distribution

    DOEpatents

    Wang, Yong; Cao, Chunshe; Li, Xiaohong Shari; Elliott, Douglas C.

    2012-06-19

    Novel methods of Fischer-Tropsch synthesis are described. It has been discovered that conducting the Fischer-Tropsch synthesis over a catalyst with a catalytically active surface layer of 35 microns or less results in a liquid hydrocarbon product with a high ratio of C.sub.5-C.sub.20:C.sub.20+. Descriptions of novel Fischer-Tropsch catalysts and reactors are also provided. Novel hydrocarbon compositions with a high ratio of C.sub.5-C.sub.20:C.sub.20+ are also described.

  16. Tomographic imaging of nonsymmetric multicomponent tailored supersonic...

    Office of Scientific and Technical Information (OSTI)

    Additional Journal Information: Journal Volume: 54; Journal Issue: 11; Journal ID: ISSN 0003-6935 Publisher: Optical Society of America Sponsoring Org: USDOE Country of ...

  17. Tailored Acicular Mullite Substrates for Multifunctional Diesel...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    SEM analysis showed that ACM DPF can be coated with relatively high catalyst washcoat without significantly affecting the porosity or pore size Therefore, it maintains a low back ...

  18. Linear nozzle with tailored gas plumes

    DOEpatents

    Leon, David D.; Kozarek, Robert L.; Mansour, Adel; Chigier, Norman

    2001-01-01

    There is claimed a method for depositing fluid material from a linear nozzle in a substantially uniform manner across and along a surface. The method includes directing gaseous medium through said nozzle to provide a gaseous stream at the nozzle exit that entrains fluid material supplied to the nozzle, said gaseous stream being provided with a velocity profile across the nozzle width that compensates for the gaseous medium's tendency to assume an axisymmetric configuration after leaving the nozzle and before reaching the surface. There is also claimed a nozzle divided into respective side-by-side zones, or preferably chambers, through which a gaseous stream can be delivered in various velocity profiles across the width of said nozzle to compensate for the tendency of this gaseous medium to assume an axisymmetric configuration.

  19. Linear nozzle with tailored gas plumes

    DOEpatents

    Kozarek, Robert L.; Straub, William D.; Fischer, Joern E.; Leon, David D.

    2003-01-01

    There is claimed a method for depositing fluid material from a linear nozzle in a substantially uniform manner across and along a surface. The method includes directing gaseous medium through said nozzle to provide a gaseous stream at the nozzle exit that entrains fluid material supplied to the nozzle, said gaseous stream being provided with a velocity profile across the nozzle width that compensates for the gaseous medium's tendency to assume an axisymmetric configuration after leaving the nozzle and before reaching the surface. There is also claimed a nozzle divided into respective side-by-side zones, or preferably chambers, through which a gaseous stream can be delivered in various velocity profiles across the width of said nozzle to compensate for the tendency of this gaseous medium to assume an axisymmetric configuration.

  20. Tailored Materials for Advanced CIDI Engines

    Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  1. Understand morphology of organic semiconductors, for better tailoring...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    for energy related applications. References: 1 H. Yan, B. A. Collins, E. Gann, C. Wang, H. Ade, and C. R. McNeill, ACS Nano 6, 677 (2012). 2 B. A. Collins, J. E. Cochran,...

  2. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    in shaping the terahertz pulses by appropriate modulation of the laser pulse. The electromagnetic spectrum. The scarcity of intense broadband sources of radiation in the...

  3. Directionally-Tailored Infrared Emission. AFRL STTR Program

    SciTech Connect

    Burckel, David Bruce; Peters, David W.; Davids, Paul; Resnick, Paul J.; Clem, Paul G.; Ginn, James; Figueiredo, Pedro; Shelton, David

    2015-10-30

    The purpose of this program is to investigate emissive metamaterials (EMM) as a path to realizing surfaces with directional absorption/emission.

  4. Engineering Property Prediction Tools for Tailored Polymer Composite Structures (49465)

    SciTech Connect

    Nguyen, Ba Nghiep; Kunc, Vlastimil

    2009-12-29

    Process and constitutive models as well as characterization tools and testing methods were developed to determine stress-strain responses, damage development, strengths and creep of long-fiber thermoplastics (LFTs). The developed models were implemented in Moldflow and ABAQUS and have been validated against LFT data obtained experimentally.

  5. Understanding and Tailoring Metal-Support Interactions in Heterogeneou...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    an archetypical catalyst used for a variety of applications, including fuel cells, electrolyzers, and processes involved in the production of renewable chemicals. Unfortunately,...

  6. Phased laser array with tailored spectral and coherence properties

    DOEpatents

    Messerly, Michael J; Dawson, Jay W; Beach, Raymond J

    2014-05-20

    Architectures for coherently combining an array of fiber-based lasers are provided. By matching their lengths to within a few integer multiples of a wavelength, the spatial and temporal properties of a single large laser are replicated, while extending the average or peak pulsed power limit.

  7. Tailored semiconducting carbon nanotube networks with enhanced thermoelectric properties

    DOE PAGES [OSTI]

    Avery, Azure D.; Zhou, Ben H.; Lee, Jounghee; Lee, Eui -Sup; Miller, Elisa M.; Ihly, Rachelle; Wesenberg, Devin; Mistry, Kevin S.; Guillot, Sarah L.; Zink, Barry L.; et al

    2016-04-04

    Thermoelectric power generation, allowing recovery of part of the energy wasted as heat, is emerging as an important component of renewable energy and energy efficiency portfolios. Although inorganic semiconductors have traditionally been employed in thermoelectric applications, organic semiconductors garner increasing attention as versatile thermoelectric materials. Here we present a combined theoretical and experimental study suggesting that semiconducting single-walled carbon nanotubes with carefully controlled chirality distribution and carrier density are capable of large thermoelectric power factors, higher than 340 μW m-1 K-2, comparable to the best-performing conducting polymers and larger than previously observed for carbon nanotube films. Furthermore, we demonstrate thatmore » phonons are the dominant source of thermal conductivity in the networks, and that our carrier doping process significantly reduces the thermal conductivity relative to undoped networks. As a result, these findings provide the scientific underpinning for improved functional organic thermoelectric composites with carbon nanotube inclusions.« less

  8. Tailoring the slow light behavior in terahertz metasurfaces ...

    Office of Scientific and Technical Information (OSTI)

    OSTI Identifier: 22398985 Resource Type: Journal Article Resource Relation: Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 18; Other Information: (c) ...

  9. Tailoring femtosecond laser pulse filamentation using plasma photonic lattices

    SciTech Connect

    Suntsov, Sergiy; Abdollahpour, Daryoush; Panagiotopoulos, Paris; Papazoglou, Dimitrios G.; Tzortzakis, Stelios; Couairon, Arnaud

    2013-07-08

    We demonstrate experimentally that by using transient plasma photonic lattices, the attributes of intense femtosecond laser filaments, such as peak intensity and length, can be dynamically controlled. The extended plasma lattice structure is generated using two co-propagating non-diffracting intense Bessel beams in water. The use of such transient lattice structures to control the competition between linear and nonlinear effects involved in filamentation opens the way for extensive control of the filamentation process.

  10. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    None

    2016-07-12

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  11. New system enables fleets to tailor maintenance programs

    SciTech Connect

    Fiscor, S.

    2007-08-15

    The Lubrizol Corporation has developed FluiPak and FluiPak Lite systems to pull engine oils and sample them continuously, helping to maintain mining equipment between oil change intervals. The FluiPak system has a control box, a sensor box and a reserve system. FluiPak Lite is simply a cut-down version of FluiPak. The article explains how the system works to detect in real time oil quality and contaminants and hence optimize drain intervals and also prolong engine component life and reduce waste oil disposal costs. 100 units are currently installed in coal operations. 5 figs., 5 photos.

  12. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    of the electron bunch with about the same duration as the laser pulse. This causes a dispersion of the electron trajectories, and the bunch develops a hole that emits short pulses...

  13. Laser beam temporal and spatial tailoring for laser shock processing

    DOEpatents

    Hackel, Lloyd; Dane, C. Brent

    2001-01-01

    Techniques are provided for formatting laser pulse spatial shape and for effectively and efficiently delivering the laser energy to a work surface in the laser shock process. An appropriately formatted pulse helps to eliminate breakdown and generate uniform shocks. The invention uses a high power laser technology capable of meeting the laser requirements for a high throughput process, that is, a laser which can treat many square centimeters of surface area per second. The shock process has a broad range of applications, especially in the aerospace industry, where treating parts to reduce or eliminate corrosion failure is very important. The invention may be used for treating metal components to improve strength and corrosion resistance. The invention has a broad range of applications for parts that are currently shot peened and/or require peening by means other than shot peening. Major applications for the invention are in the automotive and aerospace industries for components such as turbine blades, compressor components, gears, etc.

  14. Phased laser array with tailored spectral and coherence properties

    DOEpatents

    Messerly, Michael J; Dawson, Jay W; Beach, Raymond J

    2011-03-29

    Architectures for coherently combining an array of fiber-based lasers are provided. By matching their lengths to within a few integer multiples of a wavelength, the spatial and temporal properties of a single large laser are replicated, while extending the average or peak pulsed power limit.

  15. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    The technique allows tremendous flexibility in shaping the terahertz pulses by appropriate modulation of the laser pulse. The electromagnetic spectrum. The scarcity of intense ...

  16. Aluminum Tailor-Welded Blanks for High Volume Automotive Applications

    SciTech Connect

    Hovanski, Yuri; Upadhyay, Piyush; Pilli, Siva Prasad; Carlson, Blair; Carsley, John; Hartfield-Wunsch, Susan; Eisenmenger, Mark

    2014-02-04

    A Design of Experiment based approach is used to systematically investigate relationships between 8 different welding factors (4 related to tool geometry, 4 related to weld process control) and resulting weld properties including strength, elongation and formability in 1.2mm-2mm thick friction stir welding of AA5182-O for TWB application. The factors that result in most significant effects are elucidated. The interactions between several key factors like plunge depth, tool tilt, pin feature and pin length on the overall weld quality is discussed. Appropriate levels of factors that lead to excellent weld properties are also identified.

  17. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    Sandia

    2009-09-01

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  18. HIPed Tailored Ceramic Waste Forms for the Immobilization of...

    Office of Scientific and Technical Information (OSTI)

    Experimental data on the immobilization of Tc in titanate ceramics containing up to 40wt% TcO2 are also be presented. Authors: Melody L. Carter ; Martin W. A. Stewart ; Eric R. ...

  19. High-Pressure Tailored Compression: Controlled Thermodynamic Paths

    SciTech Connect

    Nguyen, J H; Orlikowski, D; Streitz, F H; Moriarty, J A; Holmes, N C

    2005-10-21

    We have recently carried out novel and exploratory dynamic experiments where the sample follows a prescribed thermodynamic path. In typical dynamic compression experiments, the samples are thermodynamically limited to the principal Hugoniot or quasi-isentrope. With recent developments in the functionally graded material impactor, we can prescribe and shape the applied pressure profile with similarly-shaped, non-monotonic impedance profile in the impactor. Previously inaccessible thermodynamic states beyond the quasi-isentropes and Hugoniot can now be reached in dynamic experiments with these impactors. In the light gas-gun experiments on copper reported here, we recorded the particle velocities of the Cu-LiF interfaces and employed hydrodynamic simulations to relate them to the thermodynamic phase diagram. Peak pressures for these experiments were on the order of megabars, and the time-scales ranged from nanoseconds to several microseconds. The strain rates of the quasi-isentropic experiments are approximately 10{sup 4} s{sup -1} to 10{sup 6} s{sup -1} in samples with thicknesses up to 5 mm. Though developed at a light-gas gun facility, such shaped pressure-profiles are also feasible in principle with laser ablation or magnetic driven compression techniques allowing for new directions to be taken in high pressure physics.

  20. Building a road map for tailoring multilayer polyelectrolyte...

    Office of Scientific and Technical Information (OSTI)

    ... salt (i.e., conditions that imitate real life) can compromise this film layering, as the ... of the layered films exhibits the quality of the layering, in particular the ...

  1. Semiconductor laser devices having lateral refractive index tailoring

    DOEpatents

    Ashby, Carol I. H.; Hadley, G. Ronald; Hohimer, John P.; Owyoung, Adelbert

    1990-01-01

    A broad-area semiconductor laser diode includes an active lasing region interposed between an upper and a lower cladding layer, the laser diode further comprising structure for controllably varying a lateral refractive index profile of the diode to substantially compensate for an effect of junction heating during operation. In embodiments disclosed the controlling structure comprises resistive heating strips or non-radiative linear junctions disposed parallel to the active region. Another embodiment discloses a multi-layered upper cladding region selectively disordered by implanted or diffused dopant impurities. Still another embodiment discloses an upper cladding layer of variable thickness that is convex in shape and symmetrically disposed about a central axis of the active region. The teaching of the invention is also shown to be applicable to arrays of semiconductor laser diodes.

  2. Tailored Working Fluids for Enhanced Binary Geothermal Power Plants

    SciTech Connect

    Mahmoud, Ahmad

    2013-01-29

    United Technologies Research Center (UTRC), in collaboration with the Georgia Institute of Technology and the National Institute of Standards and Technology will evaluate and develop fundamental and component level models, conduct experiments and generate data to support the use of mixed or enhanced working fluids for geothermal power generation applications.

  3. Tailored Acicular Mullite Substrates for Multifunctional Diesel Particulate Filters

    Energy.gov [DOE]

    SEM analysis showed that ACM DPF can be coated with relatively high catalyst washcoat without significantly affecting the porosity or pore size Therefore, it maintains a low back pressure performance at very high catalyst

  4. HIPed Tailored Ceramic Waste Forms for the Immobilization of...

    Office of Scientific and Technical Information (OSTI)

    An important element of this initiative is the separation of key radionuclides . One of the systems being developed to separate key radionuclides is the UREX+1 process. The Tc and ...

  5. High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded...

    Energy Saver

    ... of component forming Utilizing statistical formability limits validate FEA models with strain data obtained from actual stampings Technical Approach Task 1: Weld development ...

  6. Multi-functional carbon nanomaterials: Tailoring morphology for multidisciplinary applications

    SciTech Connect

    Dervishi, Enkeleda

    2015-05-14

    Carbon based nanomaterials are being developed to have many new properties and applications. Graphene, is a mono-layer 2D atomic thick structure formed from hexagons of carbon atoms bound together by sp^2hybrid bonds. A carbon nanotube (CNT) can be viewed as a sheet of graphene rolled up into a cylinder, usually 1-2 nanometers in diameter and a few microns thick. A few applications of graphene and carbon nanotubes include the development of Nanoelectronics, nanocomposite materials, Hydrogen storage and Li⁺ battery, etc.

  7. Tailored Ink For Piston-Driven Electrostatic Liquid Drop Modulator

    DOEpatents

    Wong, Raymond W.; Breton, Marcel P.; Bedford, Christine E.; Carreira, Leonard M.; Gooray, Arthur M.; Roller, George J.; Zavadil, Kevin; Galambos, Paul; Crowley, Joseph

    2005-04-19

    The present invention relates to an ink composition including water, a solvent, a solvent-soluble dye, and a surfactant, where the ink exhibits a stable liquid microemulsion phase at a first temperature and a second temperature higher than the first temperature and has a conductivity of at most about 200 .mu.S/cm and a dielectric constant of at least about 60, and methods of making such ink compositions. The present invention also relates to a method of making an ink composition for use in a microelectromechanical system-based fluid ejector. The method involves providing a solution or dispersion including a dye or a pigment and adding to the solution or dispersion an additive which includes a material that enhances dielectric permittivity and/or reduces conductivity under conditions effective to produce an ink composition having a conductivity of at most about 200 .mu.S/cm and a dielectric constant of at least about 60.

  8. Engineering Property Prediction Tools for Tailored Polymer Composite Structures

    Energy.gov [DOE]

    2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  9. Linear nozzle with tailored gas plumes and method

    DOEpatents

    Leon, David D.; Kozarek, Robert L.; Mansour, Adel; Chigier, Norman

    1999-01-01

    There is claimed a method for depositing fluid material from a linear nozzle in a substantially uniform manner across and along a surface. The method includes directing gaseous medium through said nozzle to provide a gaseous stream at the nozzle exit that entrains fluid material supplied to the nozzle, said gaseous stream being provided with a velocity profile across the nozzle width that compensates for the gaseous medium's tendency to assume an axisymmetric configuration after leaving the nozzle and before reaching the surface. There is also claimed a nozzle divided into respective side-by-side zones, or preferably chambers, through which a gaseous stream can be delivered in various velocity profiles across the width of said nozzle to compensate for the tendency of this gaseous medium to assume an axisymmetric configuration.

  10. Public Housing: A Tailored Approach to Energy Retrofits

    SciTech Connect

    Dentz, Jordan; Conlin, Francis; Podorson, David; Alaigh, Kunal

    2014-06-01

    More than 1 million HUD-supported public housing units provide rental housing for eligible low-income families across the country. A survey of over 100 public housing authorities (PHAs) across the country indicated that there is a high level of interest in developing low-cost solutions that improve energy efficiency and can be seamlessly included in the refurbishment process. Further, PHAs, have incentives (both internal and external) to reduce utility bills. ARIES worked with two PHAs to develop packages of energy efficiency retrofit measures the PHAs can cost effectively implement with their own staffs in the normal course of housing operations when units are refurbished between occupancies. The energy efficiency turnover protocols emphasized air infiltration reduction, duct sealing and measures that improve equipment efficiency. ARIES documented implementation 10 ten housing units. Total source energy consumption savings was estimated at 6%-10% based on BEopt modeling with a simple payback of 1.7 to 2.2 years. At typical housing unit turnover rates, these measures could impact hundreds of thousands of units per year nationally.

  11. Public Housing: A Tailored Approach to Energy Retrofits

    SciTech Connect

    Dentz, J.; Conlin, F.; Podorson, D.; Alaigh, K.

    2014-06-01

    Over one million HUD-supported public housing units provide rental housing for eligible low-income families across the country. A survey of over 100 PHAs across the country indicated that there is a high level of interest in developing low cost solutions that improve energy efficiency and can be seamlessly included in the refurbishment process. Further, PHAs, have incentives (both internal and external) to reduce utility bills. ARIES worked with two public housing authorities (PHAs) to develop packages of energy efficiency retrofit measures the PHAs can cost effectively implement with their own staffs in the normal course of housing operations at the time when units are refurbished between occupancies. The energy efficiency turnover protocols emphasized air infiltration reduction, duct sealing and measures that improve equipment efficiency. ARIES documented implementation in ten housing units. Reductions in average air leakage were 16-20% and duct leakage reductions averaged 38%. Total source energy consumption savings was estimated at 6-10% based on BEopt modeling with a simple payback of 1.7 to 2.2 years. Implementation challenges were encountered mainly related to required operational changes and budgetary constraints. Nevertheless, simple measures can feasibly be accomplished by PHA staff at low or no cost. At typical housing unit turnover rates, these measures could impact hundreds of thousands of unit per year nationally.

  12. Highly Ordered Tailored Three-Dimensional Hierarchical Porous...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Journal Name: Advanced Functional Materials; Related Information: Proposed for publication in Advanced Functional Materials. Research Org: Sandia National ...

  13. Tailored Materials for High Efficiency CIDI Engines (Caterpillar CRADA)

    Office of Energy Efficiency and Renewable Energy (EERE)

    2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C.

  14. Engineering Property Prediction Tools for Tailored Polymer Composite Structures

    Office of Energy Efficiency and Renewable Energy (EERE)

    2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C.

  15. Alloys in energy development

    SciTech Connect

    Frost, B.R.T.

    1984-02-01

    The development of new and advanced energy systems often requires the tailoring of new alloys or alloy combinations to meet the novel and often stringent requirements of those systems. Longer life at higher temperatures and stresses in aggressive environments is the most common goal. Alloy theory helps in achieving this goal by suggesting uses of multiphase systems and intermediate phases, where solid solutions were traditionally used. However, the use of materials under non-equilibrium conditions is now quite common - as with rapidly solidified metals - and the application of alloy theory must be modified accordingly. Under certain conditions, as in a reactor core, the rate of approach to equilibrium will be modified; sometimes a quasi-equilibrium is established. Thus an alloy may exhibit enhanced general diffusion at the same time as precipitate particles are being dispersed and solute atoms are being carried to vacancy sinks. We are approaching an understanding of these processes and can begin to model these complex systems.

  16. Influence of chemical disorder on energy dissipation and defect evolution in concentrated solid solution alloys

    SciTech Connect

    Zhang, Yanwen; Stocks, George Malcolm; Jin, Ke; Lu, Chenyang; Bei, Hongbin; Sales, Brian C.; Wang, Lumin; Béland, Laurent K.; Stoller, Roger E.; Samolyuk, German D.; Caro, Magdalena; Caro, Alfredo; Weber, William J.

    2015-10-28

    A long-standing objective in materials research is to understand how energy is dissipated in both the electronic and atomic subsystems in irradiated materials, and how related non-equilibrium processes may affect defect dynamics and microstructure evolution. Here we show that alloy complexity in concentrated solid solution alloys having both an increasing number of principal elements and altered concentrations of specific elements can lead to substantial reduction in the electron mean free path and thermal conductivity, which has a significant impact on energy dissipation and consequentially on defect evolution during ion irradiation. Enhanced radiation resistance with increasing complexity from pure nickel to binary and to more complex quaternary solid solutions is observed under ion irradiation up to an average damage level of 1 displacement per atom. Understanding how materials properties can be tailored by alloy complexity and their influence on defect dynamics may pave the way for new principles for the design of radiation tolerant structural alloys.

  17. Risk and Vulnerability Assessment Using Cybernomic Computational Models: Tailored for Industrial Control Systems

    SciTech Connect

    Abercrombie, Robert K; Sheldon, Federick T.; Schlicher, Bob G

    2015-01-01

    There are many influencing economic factors to weigh from the defender-practitioner stakeholder point-of-view that involve cost combined with development/deployment models. Some examples include the cost of countermeasures themselves, the cost of training and the cost of maintenance. Meanwhile, we must better anticipate the total cost from a compromise. The return on investment in countermeasures is essentially impact costs (i.e., the costs from violating availability, integrity and confidentiality / privacy requirements). The natural question arises about choosing the main risks that must be mitigated/controlled and monitored in deciding where to focus security investments. To answer this question, we have investigated the cost/benefits to the attacker/defender to better estimate risk exposure. In doing so, it s important to develop a sound basis for estimating the factors that derive risk exposure, such as likelihood that a threat will emerge and whether it will be thwarted. This impact assessment framework can provide key information for ranking cybersecurity threats and managing risk.

  18. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z

    DOE PAGES [OSTI]

    Jennings, Christopher A.; Ampleford, David J.; Lamppa, Derek C.; Hansen, Stephanie B.; Jones, Brent Manley; Harvey-Thompson, Adam James; Jobe, Marc Ronald Lee; Reneker, Joseph; Rochau, Gregory A.; Cuneo, Michael Edward; et al

    2015-05-18

    Large diameter multi-shell gas puffs rapidly imploded by high current (~20 MA, ~100 ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ~13 keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiativemore » output from this combined system. Furthermore, guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-Rayleigh–Taylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.« less

  19. Tailoring of absorption edge by thermal annealing in tin oxide thin films

    SciTech Connect

    Thakur, Anup; Gautam, Sanjeev; Kumar, Virender; Chae, K. H.; Lee, Ik-Jae; Shin, Hyun Joon

    2015-05-15

    Tin oxide (SnO{sub 2}) thin films were deposited by radio-frequency (RF) magnetron sputtering on silicon and glass substrates in different oxygen-to-argon gas-flow ratio (O{sub 2}-to-Ar = 0%, 10%, 50%). All films were deposited at room temperature and fixed working pressures, 10 mTorr. The X-ray diffraction (XRD) measurement suggests that all films were crystalline in nature except film deposited in argon environment. Thin films were annealed in air at 200 C, 400 C and 600 C for two hours. All films were highly transparent except the film deposited only in the argon environment. It was also observed that transparency was improved with annealing due to decrease in oxygen vacancies. Atomic force microscopy (AFM), results showed that the surface of all the films were highly flat and smooth. Blue shift was observed in the absorption edge with annealing temperature. It was also observed that there was not big change in the absorption edge with annealing for films deposited in 10% and 50% oxygen-to-argon gas-flow ratio.

  20. Vehicle Technologies Office Merit Review 2016: Tailoring Spinel Electrodes for High Capacity Li-Ion Cells

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation given by Argonne National Laboratory (ANL) at the 2016 DOE Vehicle Technologies Office and Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting about Batteries

  1. Computational Nanophotonics: modeling optical interactions and transport in tailored nanosystem architectures

    SciTech Connect

    Schatz, George; Ratner, Mark

    2014-02-27

    This report describes research by George Schatz and Mark Ratner that was done over the period 10/03-5/09 at Northwestern University. This research project was part of a larger research project with the same title led by Stephen Gray at Argonne. A significant amount of our work involved collaborations with Gray, and there were many joint publications as summarized later. In addition, a lot of this work involved collaborations with experimental groups at Northwestern, Argonne, and elsewhere. The research was primarily concerned with developing theory and computational methods that can be used to describe the interaction of light with noble metal nanoparticles (especially silver) that are capable of plasmon excitation. Classical electrodynamics provides a powerful approach for performing these studies, so much of this research project involved the development of methods for solving Maxwell’s equations, including both linear and nonlinear effects, and examining a wide range of nanostructures, including particles, particle arrays, metal films, films with holes, and combinations of metal nanostructures with polymers and other dielectrics. In addition, our work broke new ground in the development of quantum mechanical methods to describe plasmonic effects based on the use of time dependent density functional theory, and we developed new theory concerned with the coupling of plasmons to electrical transport in molecular wire structures. Applications of our technology were aimed at the development of plasmonic devices as components of optoelectronic circuits, plasmons for spectroscopy applications, and plasmons for energy-related applications.

  2. Relaxed active space: Fixing tailored-CC with high order coupled cluster. II

    SciTech Connect

    Melnichuk, Ann Bartlett, Rodney J.

    2014-02-14

    Due to the steep increase in computational cost with the inclusion of higher-connected cluster operators in coupled-cluster applications, it is usually not practical to use such methods for larger systems or basis sets without an active space partitioning. This study generates an active space subject to unambiguous statistical criteria to define a space whose size permits treatment at the CCSDT level. The automated scheme makes it unnecessary for the user to judge whether a chosen active space is sufficient to correctly solve the problem. Two demanding applications are presented: twisted ethylene and the transition states for the bicyclo[1,1,0]butane isomerization. As bi-radicals both systems require at least a CCSDT level of theory for quantitative results, for the geometries and energies.

  3. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z

    SciTech Connect

    Jennings, C. A.; Ampleford, D. J.; Lamppa, D. C.; Hansen, S. B.; Jones, B.; Harvey-Thompson, A. J.; Jobe, M.; Strizic, T.; Reneker, J.; Rochau, G. A.; Cuneo, M. E.

    2015-05-15

    Large diameter multi-shell gas puffs rapidly imploded by high current (?20 MA, ?100?ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ?13?keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiative output from this combined system. Guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-RayleighTaylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.

  4. (Bio)Chemical Tailoring of Biogenic 3-D Nanopatterned Templates with Energy-Relevant Functionalities

    SciTech Connect

    Sandhage, Kenneth H; Kroger, Nils

    2014-09-08

    The overall aim of this research has been to obtain fundamental understanding of (bio)chemical methodologies that will enable utilization of the unique 3-D nanopatterned architectures naturally produced by diatoms for the syntheses of advanced functional materials attractive for applications in energy harvesting/conversion and storage. This research has been conducted in three thrusts: Thrust 1 (In vivo immobilization of proteins in diatom biosilica) is directed towards elucidating the fundamental mechanism(s) underlying the cellular processes of in vivo immobilization of proteins in diatom silica. Thrust 2 (Shape-preserving reactive conversion of diatom biosilica into porous, high-surface area inorganic replicas) is aimed at understanding the fundamental mechanisms of shape preservation and nanostructural evolution associated with the reactive conversion and/or coating-based conversion of diatom biosilica templates into porous inorganic replicas. Thrust 3 (Immobilization of energy-relevant enzymes in diatom biosilica and onto diatom biosilica-derived inorganic replicas) involves use of the results from both Thrust 1 and 2 to develop strategies for in vivo and in vitro immobilization of enzymes in/on diatom biosilica and diatom biosilica-derived inorganic replicas, respectively. This Final Report describes progress achieved in all 3 of these thrusts.

  5. Tailored Materials for Improved Internal Combustion Engine Efficiency (Agreement ID:23725)

    Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  6. Vehicle Technologies Office Merit Review 2015: Tailored Materials for Improved Internal Combustion Engine Efficiency

    Energy.gov [DOE]

    Presentation given by Pacific Northwest National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about...

  7. Vehicle Technologies Office Merit Review 2014: Tailored Materials for Improved Internal Combustion Engine Efficiency

    Energy.gov [DOE]

    Presentation given by Pacific Northwest National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about...

  8. Tailoring the physical properties of Ni-based single-phase equiatomic...

    Office of Scientific and Technical Information (OSTI)

    Authors: Jin, Ke 1 ; Sales, Brian C 1 ; Stocks, George Malcolm 1 ; Samolyuk, German D. 1 ; Daene, Markus 2 ; Weber, William J. 3 ; Zhang, Yanwen 3 ; Bei, Hongbin 1 ...

  9. Collimated proton acceleration in light sail regime with a tailored pinhole target

    SciTech Connect

    Wang, H. Y.; Zepf, M.; Yan, X. Q.

    2014-06-15

    A scheme for producing collimated protons from laser interactions with a diamond-like-carbon?+?pinhole target is proposed. The process is based on radiation pressure acceleration in the multi-species light-sail regime [B. Qiao et al., Phys. Rev. Lett. 105, 155002 (2010); T. P. Yu et al., Phys. Rev. Lett. 105, 065002 (2010)]. Particle-in-cell simulations demonstrate that transverse quasistatic electric field at TV/m level can be generated in the pinhole. The transverse electric field suppresses the transverse expansion of protons effectively, resulting in a higher density and more collimated proton beam compared with a single foil target. The dependence of the proton beam divergence on the parameters of the pinhole is also investigated.

  10. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z

    SciTech Connect

    Jennings, Christopher A.; Ampleford, David J.; Lamppa, Derek C.; Hansen, Stephanie B.; Jones, Brent Manley; Harvey-Thompson, Adam James; Jobe, Marc Ronald Lee; Reneker, Joseph; Rochau, Gregory A.; Cuneo, Michael Edward; Strizic, T.

    2015-05-18

    Large diameter multi-shell gas puffs rapidly imploded by high current (~20 MA, ~100 ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ~13 keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiative output from this combined system. Furthermore, guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-Rayleigh–Taylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.

  11. Tailoring next-generation biofuels and their combustion in next-generation engines.

    SciTech Connect

    Gladden, John Michael; Wu, Weihua; Taatjes, Craig A.; Scheer, Adam Michael; Turner, Kevin M.; Yu, Eizadora T.; O'Bryan, Greg; Powell, Amy Jo; Gao, Connie W.

    2013-11-01

    Increasing energy costs, the dependence on foreign oil supplies, and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals. The strategy for producing next-generation biofuels must include efficient processes for biomass conversion to liquid fuels and the fuels must be compatible with current and future engines. Unfortunately, biofuel development generally takes place without any consideration of combustion characteristics, and combustion scientists typically measure biofuels properties without any feedback to the production design. We seek to optimize the fuel/engine system by bringing combustion performance, specifically for advanced next-generation engines, into the development of novel biosynthetic fuel pathways. Here we report an innovative coupling of combustion chemistry, from fundamentals to engine measurements, to the optimization of fuel production using metabolic engineering. We have established the necessary connections among the fundamental chemistry, engine science, and synthetic biology for fuel production, building a powerful framework for co-development of engines and biofuels.

  12. Manganese Doping of Magnetic Iron Oxide Nanoparticles: Tailoring Surface Reactivity for a Regenerable Heavy Metal Sorbent

    SciTech Connect

    Warner, Cynthia L.; Chouyyok, Wilaiwan; Mackie, Katherine E.; Neiner, Doinita; Saraf, Laxmikant; Droubay, Timothy C.; Warner, Marvin G.; Addleman, Raymond S.

    2012-02-28

    A method for tuning the analyte affinity of magnetic, inorganic nanostructured sorbents for heavy metal contaminants is described. The manganese-doped iron oxide nanoparticle sorbents have a remarkably high affinity compared to the precursor material. Sorbent affinity can be tuned toward an analyte of interest simply by adjustment of the dopant quantity. The results show that following the Mn doping process there is a large increase in affinity and capacity for heavy metals (i.e., Co, Ni, Zn, As, Ag, Cd, Hg, and Tl). Capacity measurements were carried out for the removal of cadmium from river water and showed significantly higher loading than the relevant commercial sorbents tested for comparison. The reduction in Cd concentration from 100 ppb spiked river water to 1 ppb (less than the EPA drinking water limit of 5 ppb for Cd) was achieved following treatment with the Mn-doped iron oxide nanoparticles. The Mn-doped iron oxide nanoparticles were able to load 1 ppm of Cd followed by complete stripping and recovery of the Cd with a mild acid wash. The Cd loading and stripping is shown to be consistent through multiple cycles with no loss of sorbent performance.

  13. Toward tailorable surfaces: A combined theoretical and experimental study of lanthanum niobate layered perovskites

    SciTech Connect

    Di Tommaso, Stefania E-mail: frederic.labat@chimie-paristech.fr; Giannici, Francesco; Mossuto Marculescu, Adriana; Martorana, Antonino; Adamo, Carlo; Labat, Frdric E-mail: frederic.labat@chimie-paristech.fr

    2014-07-14

    A comprehensive theoretical investigation of the MLaNb{sub 2}O{sub 7} (M = H, Li, Na, K, Rb, and Cs) series of ion-exchangeable layered perovskite is presented. These perovskites are in particular interesting in view of their potential applications as inorganic supports for the design of new hybrid inorganic-organic proton conductors. In particular, their structural and electronic properties have been investigated by periodic calculations in the framework of Density Functional Theory, using different exchange-correlation functionals. A general very good agreement with the available experimental (XRD, NPD, and EXAFS) data has been found. The structure of the protonated HLaNb{sub 2}O{sub 7} form has also been further clarified and a new tetragonal space group is proposed for this compound, better reproducing the experimental cell parameters and yielding to a more realistic picture of the system. The electronic investigation highlighted that all the compounds considered are very similar to each other and that the interaction between interlayer cations and perovskite slabs is purely ionic, except for the proton that is, instead, covalently bound.

  14. Band-gap tailoring of ZnO by means of heavy Al doping

    SciTech Connect

    Sernelius, B.E.; Berggren, K.; Jin, Z.; Hamberg, I.; Granqvist, C.G.

    1988-06-15

    Films of ZnO:Al were produced by weakly reactive dual-target magnetron sputtering. Optical band gaps, evaluated from spectrophotometric data, were widened in proportion to the Al doping. The widening could be quantitatively reconciled with an effective-mass model for n-doped semiconductors, provided the polar character of ZnO was accounted for.

  15. A family of peroxo-titanate materials tailored for optimal strontium...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: AC04-94AL85000 Resource Type: Journal Article Resource Relation: Journal Name: Proposed for presentation at the Chemistry of Materials. Research Org: Sandia ...

  16. Magnetic properties of granular CoCrPt:SiO{sub 2} films as tailored...

    Office of Scientific and Technical Information (OSTI)

    Ion irradiation simulations suggest that this is caused by strong intermixing at the grain and layer interfaces. Authors: Tibus, Stefan ; Springer, Felix 1 ; Institute of ...

  17. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z.

    SciTech Connect

    Jennings, Christopher A.; Ampleford, David J.; Lamppa, Derek C.; Hansen, Stephanie B.; Jones, Brent Manley; Harvey-Thompson, Adam James; Jobe, Marc Ronald Lee; Reneker, Joseph; Rochau, Gregory A.; Cuneo, Michael Edward; Strizic, T.

    2015-05-18

    Large diameter multi-shell gas puffs rapidly imploded by high current (~20 MA, ~100 ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ~13 keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiative output from this combined system. Furthermore, guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-Rayleigh–Taylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.

  18. Enhancing ionic conductivity of bulk single-crystal yttria-stabilized zirconia by tailoring dopant distribution

    SciTech Connect

    Lee, E.; Prinz, F. B.; Cai, W.

    2011-02-11

    We present an ab initiobased kinetic Monte Carlo model for ionic conductivity in single-crystal yttria-stabilized zirconia. Ionic interactions are taken into account by combining density functional theory calculations and the cluster expansion method and are found to be essential in reproducing the effective activation energy observed in experiments. The model predicts that the effective energy barrier can be reduced by 0.150.25 eV by arranging the dopant ions into a superlattice.

  19. Au and Pt nanoparticle supported catalysts tailored for H-2 production: From models to powder catalysts

    DOE PAGES [OSTI]

    T. D. Nguyen-Phan; Baber, A. E.; Rodriguez, J. A.; Senanayake, S. D.

    2015-12-10

    The use of metal nanoparticles (NPs), including Au and Pt, supported over oxides has been pivotal, and is ever increasing in enabling catalytic reactions which target the production of hydrogen. We review here the most recent works pertaining to the fundamental understanding of the structure, morphology, growth, characterization, and intrinsic phenomenological properties of Au– and Pt– based catalysts that influence the reactivity and selectivity to target hydrogen production. We draw on surface science and theoretical methods of model and powder catalysts using high resolution imaging, spectroscopy, scattering experiments, and theoretical studies. Based on these insights we identify key aspects ofmore » studies of supported metal nanoparticle (NP) catalysts for several reactions. The main focus of this review is on the intersection of catalytic chemistry related to the water-gas shift (WGS), oxygenate steam reforming (OSR), and solarassisted reactions (SAR).« less

  20. Tailored fatty acid synthesis via dynamic control of fatty acid elongation

    SciTech Connect

    Torella, JP; Ford, TJ; Kim, SN; Chen, AM; Way, JC; Silver, PA

    2013-07-09

    Medium-chain fatty acids (MCFAs, 4-12 carbons) are valuable as precursors to industrial chemicals and biofuels, but are not canonical products of microbial fatty acid synthesis. We engineered microbial production of the full range of even-and odd-chain-length MCFAs and found that MCFA production is limited by rapid, irreversible elongation of their acyl-ACP precursors. To address this limitation, we programmed an essential ketoacyl synthase to degrade in response to a chemical inducer, thereby slowing acyl-ACP elongation and redirecting flux from phospholipid synthesis to MCFA production. Our results show that induced protein degradation can be used to dynamically alter metabolic flux, and thereby increase the yield of a desired compound. The strategy reported herein should be widely useful in a range of metabolic engineering applications in which essential enzymes divert flux away from a desired product, as well as in the production of polyketides, bioplastics, and other recursively synthesized hydrocarbons for which chain-length control is desired.

  1. Vehicle Technologies Office Merit Review 2014: High Speed Joining of Dissimilar Alloy Aluminum Tailor Welded Blanks

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation given by Pacific Northwest National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high...

  2. Tailoring dye-sensitized upconversion nanoparticle excitation bands towards excitation wavelength selective imaging

    DOE PAGES [OSTI]

    Wu, Xiang; Lee, Hyungseok; Bilsel, Osman; Zhang, Yuanwei; Li, Zhanjun; Chen, Teresa; Liu, Yi; Duan, Chunying; Shen, Jie; Punjabi, Amol; et al

    2015-01-01

    One of the key roadblocks in UCNP development is its extremely limited choices of excitation wavelengths. We report a generic design to program UCNPs to possess highly tunable dye characteristic excitation bands. Using such distinctive properties, we were able to develop a new excitation wavelength selective security imaging. Finally, this work unleashed the greater freedom of the excitation wavelengths of the upconversion nanoparticles and we believe it is a game-changer in the field and this method will enable numerous applications that are currently limited by existing UCNPs.

  3. Nuclear forward scattering vs. conventional Mossbauer studies of atomically tailored Eu-based materials.

    SciTech Connect

    Konjhodzic, A.; Adamczyk, A.; Hasan, Z.; Alp, E. E.; Sturhahn, W.; Zhao, J.; Carroll, J. J.; Vagizov, F.; Univ. of Philadelphia; Youngstown State Univ.

    2006-01-01

    With the decrease in size of devices, rapid characterization of nano-devices is an inevitable necessity. It is shown that Moessbauer spectroscopy using synchrotron radiation from the advanced photon source provides such a tool of investigation. Results are presented and compared for conventional Moessbauer and Nuclear Forward Scattering for {sup 151}Eu-doped magnesium sulfide as an example, especially at low concentrations.

  4. Implementation of New Process Models for Tailored Polymer Composite Structures into Processing Software Packages

    SciTech Connect

    Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin; Phelps, Jay; Tucker III, Charles L.; Kunc, Vlastimil; Bapanapalli, Satish K.; Smith, Mark T.

    2010-02-23

    This report describes the work conducted under the Cooperative Research and Development Agreement (CRADA) (Nr. 260) between the Pacific Northwest National Laboratory (PNNL) and Autodesk, Inc. to develop and implement process models for injection-molded long-fiber thermoplastics (LFTs) in processing software packages. The structure of this report is organized as follows. After the Introduction Section (Section 1), Section 2 summarizes the current fiber orientation models developed for injection-molded short-fiber thermoplastics (SFTs). Section 3 provides an assessment of these models to determine their capabilities and limitations, and the developments needed for injection-molded LFTs. Section 4 then focuses on the development of a new fiber orientation model for LFTs. This model is termed the anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model as it explores the concept of anisotropic rotary diffusion to capture the fiber-fiber interaction in long-fiber suspensions and uses the reduced strain closure method of Wang et al. to slow down the orientation kinetics in concentrated suspensions. In contrast to fiber orientation modeling, before this project, no standard model was developed to predict the fiber length distribution in molded fiber composites. Section 5 is therefore devoted to the development of a fiber length attrition model in the mold. Sections 6 and 7 address the implementations of the models in AMI, and the conclusions drawn from this work is presented in Section 8.

  5. Solvent tailoring in coal liquefaction. Quarterly report, July-September 1983

    SciTech Connect

    Tarrer, A.R.; Curtis, C.W.; Guin, J.A.; Williams, D.C.

    1983-01-01

    A series of twenty-three aromatic compounds were ranked for their donor solvent efficacy for the dissolution of Western Kentucky No. 9/14 coal. The transfer of hydrogen from the solvent to the coal fragments, as measured by coal conversion, was examined at three levels of available hydrogen. The hydrogen donors are ranked according to their ability to convert coal to THF solubles. Aromatic analogs of the donors showed little ability to convert coal to THF solubles. Factors which influence hydrogen donation include the presence of heteroatoms or substituents both internal and external to the aromatic or hydroaromatic rings, the degree of hydrogenation, the aromaticity or nonaromaticity of the hydroaromatics, and the presence of five-membered rings. A relationship between heats of formation and hydrogen donor ability is shown for hydroaromatics within two ring or three ring homologous series. A model hydrogen acceptor, benzophenone, is also used to rank donors. No correlation exists in the ranking of hydrogen donors by the model acceptor used in this work and in other experimental studies and that obtained by conversion of Western Kentucky coal at typical liquefaction conditions. 24 references.

  6. Vehicle Technologies Office Merit Review 2016: Active, Tailorable Adhesives for Dissimilar Material Bonding, Repair and Assembly

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation given by Michigan State University at the 2016 DOE Vehicle Technologies Office and Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting about Lightweighting

  7. Tailoring Pore Size of Nitrogen-Doped Hollow Carbon Nanospheres for Confi ning Sulfur in LithiumSulfur Batteries

    SciTech Connect

    Zhou, Weidong; Wang, Chong M.; Zhang, Quiglin; Abruna, Hector D.; He, Yang; Wang, Jiangwei; Mao, Scott X.; Xiao, Xingcheng

    2015-08-19

    Three types of nitrogen-doped hollow carbon spheres with different pore sized porous shells are prepared to investigate the performance of sulfur confinement. The reason that why no sulfur is observed in previous research is determined and it is successfully demonstrated that the sulfur/polysulfide will overflow the porous carbon during the lithiation process.

  8. Tailoring the crystal structure of TiO{sub 2} thin films from the anatase to rutile phase

    SciTech Connect

    Kotake, Haruka; Jia, Junjun; Nakamura, Shin-ichi; Shigesato, Yuzo; Okajima, Toshihiro

    2015-07-15

    TiO{sub 2} films with various Sn concentrations were deposited on quartz substrates using rf reactive magnetron sputtering. The crystal structure was investigated by using x-ray diffraction, Raman spectroscopy, and transmission electron microscopy, and the chemical states of Ti and Sn were analyzed by x-ray absorption near edge structure (XANES) spectroscopy. Without Sn doping, TiO{sub 2} films change the crystal structure from rutile to anatase as the total gas pressure increases in the sputtering deposition. On the other hand, Sn doping induces the transformation of TiO{sub 2} crystalline structure from anatase to rutile phase, where the XANES spectra implied that Sn substitutes into Ti site of rutile TiO{sub 2}. Atomic force microscope analyses revealed that the Sn-doped TiO{sub 2} films exhibited a flat surface with the roughness of approximately 2 nm.

  9. Tailoring the coercivity in ferromagnetic ZnO thin films by 3d and 4f elements codoping

    SciTech Connect

    Lee, J. J.; Xing, G. Z. Yi, J. B.; Li, S.; Chen, T.; Ionescu, M.

    2014-01-06

    Cluster free, Co (3d) and Eu (4f) doped ZnO thin films were prepared using ion implantation technique accompanied by post annealing treatments. Compared with the mono-doped ZnO thin films, the samples codoped with Co and Eu exhibit a stronger magnetization with a giant coercivity of 1200 Oe at ambient temperature. This was further verified through x-ray magnetic circular dichroism analysis, revealing the exchange interaction between the Co 3d electrons and the localized carriers induced by Eu{sup 3+} ions codoping. The insight gained with modulating coercivity in magnetic oxides opens up an avenue for applications requiring non-volatility in spintronic devices.

  10. Tailored benzoxazines as novel resin systems for printed circuit boards in high temperature e-mobility applications

    SciTech Connect

    Troeger, K. Darka, R. Khanpour Neumeyer, T. Altstaedt, V.

    2014-05-15

    This study focuses on the development of Bisphenol-F-benzoxazine resins blended with different ratios of a trifunctional epoxy resin suitable as matrix for substrates for high temperature printed circuit board (HT-PCB) applications. With the benzoxazine blends glass transition temperatures of more than 190 °C could be achieved in combination with a coefficient of thermal expansion in thickness direction (z-CTE) of less than 60 ppm/K without adding any fillers. This shows the high potential of the benzoxazine-epoxy blend systems as substrate materials for HT-PCBs. To understand the thermal behavior of the different formulations, the apparent crosslink density was calculated based on data from Dynamic Mechanical Analysis. Laminates in laboratory scale were prepared and characterized to demonstrate the transformation of the neat resin properties into real electronic substrate properties. The produced laminates exhibit a z-CTE below 40 ppm/K.

  11. Tailoring the physical properties of Ni-based single-phase equiatomic alloys by modifying the chemical complexity

    DOE PAGES [OSTI]

    Jin, Ke; Sales, Brian C.; Stocks, George Malcolm; Samolyuk, German D.; Daene, Markus; Weber, William J.; Zhang, Yanwen; Bei, Hongbin

    2016-02-01

    We discovered that equiatomic alloys (e.g. high entropy alloys) have recently attracted considerable interest due to their exceptional properties, which might be closely related to their extreme disorder induced by the chemical complexity. To understand the effects of chemical complexity on their fundamental physical properties, a family of (eight) Ni-based, face-center-cubic (FCC), equiatomic alloys, extending from elemental Ni to quinary high entropy alloys, has been synthesized, and their electrical, thermal, and magnetic properties are systematically investigated in the range of 4–300 K by combining experiments with ab initio Korring-Kohn-Rostoker coherent-potential-approximation (KKR-CPA) calculations. The scattering of electrons is significantly increased duemore » to the chemical (especially magnetic) disorder. It has weak correlation with the number of elements but strongly depends on the type of elements. Thermal conductivities of the alloys are largely lower than pure metals, primarily because the high electrical resistivity suppresses the electronic thermal conductivity. Moreover, the temperature dependence of the electrical and thermal transport properties is further discussed, and the magnetization of five alloys containing three or more elements is measured in magnetic fields up to 4 T.« less

  12. Tailoring surface properties and structure of layered double hydroxides using silanes with different number of functional groups

    SciTech Connect

    Tao, Qi; He, Hongping; Li, Tian; Frost, Ray L.; Zhang, Dan; He, Zisen

    2014-05-01

    Four silanes, trimethylchlorosilane (TMCS), dimethyldiethoxylsilane (DMDES), 3-aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS), were adopted to graft layered double hydroxides (LDH) via an induced hydrolysis silylation method (IHS). Fourier transform infrared spectra (FTIR) and {sup 29}Si MAS nuclear magnetic resonance spectra ({sup 29}Si MAS NMR) indicated that APTES and TEOS can be grafted onto LDH surfaces via condensation with hydroxyl groups of LDH, while TMCS and DMDES could only be adsorbed on the LDH surface with a small quantity. A combination of X-ray diffraction patterns (XRD) and {sup 29}Si MAS NMR spectra showed that silanes were exclusively present in the external surface and had little influence on the long range order of LDH. The surfactant intercalation experiment indicated that the adsorbed and/or grafted silane could not fix the interlamellar spacing of the LDH. However, they will form crosslink between the particles and affect the further surfactant intercalation in the silylated samples. The replacement of water by ethanol in the tactoids and/or aggregations and the polysiloxane oligomers formed during silylation procedure can dramatically increase the value of BET surface area (S{sub BET}) and total pore volumes (V{sub p}) of the products. - Graphical abstract: The replacement of water by ethanol in the tactoids and aggregations of LDHs, and the polysiloxane oligomers formed during silylation process can dramatically increase the BET surface area (S{sub BET}) and the total pore volume (V{sub p}) of the silylated products. - Highlights: Silanes with multifunctional groups were grafted onto LDH surface in C{sub 2}H{sub 5}OH medium. The number of hydrolysable groups in silanes affects the structure of grafted LDH. Replacement of H{sub 2}O by C{sub 2}H{sub 5}OH in aggregations increases S{sub BET} and V{sub p} of grafted LDH. Polysiloxane oligomers contribute to the increase of S{sub BET} and V{sub p} of grafted LDH.

  13. Tailoring the energy level alignment at the Co/Alq{sub 3} interface by controlled cobalt oxidation

    SciTech Connect

    Haag, Norman; Steil, Sabine; Großmann, Nicolas; Fetzer, Roman; Cinchetti, Mirko; Aeschlimann, Martin

    2013-12-16

    We have studied the influence of oxygen exposure at the prototypical interface between cobalt and the organic semiconductor tris(8-hydroxyquinoline)aluminum (III) (Alq{sub 3}) by photoemission spectroscopy. We find that oxidation of the cobalt leads to a gradual suppression of hybrid interface states, to a progressive change in the work function and to a continuous energetic shift of the molecular orbitals towards higher binding energies. Based on these observations, we propose controlled oxidation of the ferromagnetic electrode as an easy and effective possibility to tune the performance of organic spintronics devices.

  14. Gasifier feed: Tailor-made from Illinois coals. Interim final technical report, September 1, 1991--August 31, 1992

    SciTech Connect

    Ehrlinger, H.P. III; Lytle, J.; Frost, R.R.; Lizzio, A.; Kohlenberger, L.; Brewer, K.

    1992-12-31

    The main purpose of this project is to produce a feedstock from preparation plant fines from an Illinois coal that is ideal for a slurry fed, slagging, entrained-flow coal gasifier. The high sulfur content and high Btu value of Illinois coals are particularly advantageous in such a gasifier; preliminary calculations indicate that the increased cost of removing sulfur from the gas from a high sulfur coal is more than offset by the increased revenue from the sale of the elemental sulfur; additionally the high Btu Illinois coal concentrates more energy into the slurry of a given coal to water ratio. The Btu is higher not only because of the higher Btu value of the coal but also because Illinois coal requires less water to produce a pumpable slurry than western coal, i.e., as little as 30--35% water may be used for Illinois coal as compared to approximately 45% for most western coals. Destec Energy, a wholly-owned subsidiary of Dow Chemical Company, will provide guidelines and test compatibility of the slurries developed for gasification feedstock. Williams Technologies, Inc., will provide their expertise in long distance slurry pumping, and test selected products for viscosity, pumpability, and handleability. The Illinois State Geological Survey will study methods for producing clean coal/water slurries from preparation plant wastes including the concentration of pyritic sulfur into the coal slurry to increase the revenue from elemental sulfur produced during gasification operations, and decrease the pyritic sulfur content of the waste streams. ISGS will also test the gasification reactivity of the coals.

  15. Gasifier feed: Tailor-made from Illinois coals. Final technical report, September 1, 1991--December 31, 1992

    SciTech Connect

    Ehrlinger, H.P. III; Lytle, J.M.; Frost, R.R.; Lizzio, A.A.; Kohlenberger, L.B.; Brewer, K.K. |||

    1992-12-31

    The main purpose of this project was to produce a feedstock from preparation plant fines from an Illinois (IL) coal that is ideal for a slurry fed, slagging, entrained-flow coal gasifier. The high-sulfur content and high-Btu value of IL coals are Particularly advantageous in such a gasifier; preliminary-calculations indicate that the increased cost of removing sulfur from the gas from a high-sulfur coal is more than offset b the increased revenue from the sale of the elemental sulfur; additionally the high-Btu IL coal concentrates more energy into the slurry of a given coal to water ratio. The Btu is--higher not only because of the hither Btu value of the coal but also because IL coal requires less water to produce a pumpable slurry than western coal, i.e., as little as 30--35% water may be used for IL coal as compared to approximately 45% for most western coals. During the contract extension, additional coal testing was completed confirming the fact that coal concentrates can be made from plant waste under a variety of flotation conditions 33 tests were conducted, yielding an average of 13326 Btu with 9.6% ash while recovering 86.0%-Of the energy value.

  16. Volume 1, 1st Edition, Multiscale Tailoring of Highly Active and Stable Nanocomposite Catalysts, Final Technical Report

    SciTech Connect

    Veser, Goetz

    2009-08-31

    Nanomaterials have gained much attention as catalysts since the discovery of exceptional CO oxidation activity of nanoscale gold by Haruta. However, many studies avoid testing nanomaterials at the high-temperatures relevant to reactions of interest for the production of clean energy (T > 700C). The generally poor thermal stability of catalytically active noble metals has thus far prevented significant progress in this area. We have recently overcome the poor thermal stability of nanoparticles by synthesizing a platinum barium-hexaaluminate (Pt-BHA) nanocomposite which combines the high activity of noble metal nanoparticles with the thermal stability of hexaaluminates. This Pt-BHA nanocomposite demonstrates excellent activity, selectivity, and long-term stability in CPOM. Pt-BHA is anchored onto a variety of support structures in order to improve the accessibility, safety, and reactivity of the nanocatalyst. Silica felts prove to be particularly amenable to this supporting procedure, with the resulting supported nanocatalyst proving to be as active and stable for CPOM as its unsupported counterpart. Various pre-treatment conditions are evaluated to determine their effectiveness in removing residual surfactant from the active nanoscale platinum particles. The size of these particles is measured across a wide temperature range, and the resulting plateau of stability from 600-900C can be linked to a particle caging effect due to the structure of the supporting ceramic framework. The nanocomposites are used to catalyze the combustion of a dilute methane stream, and the results indicate enhanced activity for both Pt-BHA as well as ceria-doped BHA, as well as an absence of internal mass transfer limitations at the conditions tested. In water-gas shift reaction, nanocomposite Pt-BHA shows stability during prolonged WGS reaction and no signs of deactivation during start-up/shut-down of the reactor. The chemical and thermal stability, low molecular weight, and wealth of literature on the formation of mesoporous silica materials motivated investigations of nanocomposite silica catalysts. High surface area silicas are synthesized via sol-gel methods, and the addition of metal-salts lead to the formation of stable nanocomposite Ni- and Fe- silicates. The results of these investigations have increased the fundamental understanding and improved the applicability of nanocatalysts for clean energy applications.

  17. Capping layer-tailored interface magnetic anisotropy in ultrathin Co{sub 2}FeAl films

    SciTech Connect

    Belmeguenai, M. Zighem, F.; Chérif, S. M.; Gabor, M. S. Petrisor, T.; Tiusan, C.

    2015-01-14

    Co{sub 2}FeAl (CFA) thin films of various thicknesses (2 nm ≤ d ≤ 50 nm) have been grown on (001) MgO single crystal substrates and then capped with Cr, V, and Ta. Their magnetic and structural properties have been studied by x-ray diffraction (XRD), vibrating sample magnetometry, and broadband microstrip ferromagnetic resonance (MS-FMR). The XRD revealed that the films are epitaxial with the cubic [001] CFA axis normal to the substrate plane and that the chemical order varies from the B2 phase to the A2 phase when decreasing the thickness. The deduced lattice parameters showed that the Cr-capped films exhibit a larger tetragonal distortion, as compared with the films capped with V or Ta. The presence of magnetic dead layers has been observed in CFA samples capped with V and Ta but not in the case of the Cr-capped ones. The effective magnetization, deduced from the fit of MS-FMR measurements, increases (decreases) linearly with the CFA inverse thickness (1/d) for the Cr-capped (Ta-capped) films while it is constant for the V-capped ones. This allows quantifying the perpendicular surface anisotropy coefficients of −0.46 erg/cm{sup 2} and 0.74 erg/cm{sup 2} for Cr and Ta-capped films, respectively. Moreover, the fourfold and the uniaxial anisotropy fields, measured in these films, showed different trends with a respect to the CFA inverse thickness. This allows inferring that a non-negligible part of the fourfold magnetocrystalline term is of interfacial origin.

  18. Novel cross-linked polystyrenes with large space network as tailor-made catalyst supports for sustainable media

    DOE PAGES [OSTI]

    Marrocchi, Assunta; Adriaensens, Peter; Bartollini, Elena; Barkakaty, Balaka; Carleer, Robert; Chen, Jihua; Hensley, Dale K.; Petrucci, Chiara; Tassi, Marco; Vaccaro, Luigi

    2015-10-09

    For a novel class of polystyrene-based gel-type resins (SPACeR, SP), containing the large 1,4-bis (4-vinylphenoxy)benzene cross-linker, is introduced; SP-immobilized 1,5,7-triazabicyclo [4.4.0]dec-5-ene (TBD) and triethylamine (TEA) bases are synthesized and characterized in terms of their structural, thermal and morphological features, and their catalytic efficiency in a series of fundamental chemical transformations under solvent-free conditions is investigated.

  19. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Spintronic devices promise new faster and lower energy-consumption electronic systems. ... In this paper, by utilizing density functional theory and non-equilibrium green function ...

  20. PowerPoint Presentation

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Nat. Photonics 2010 Bae et al. Nat. Nanotech. 2010 Understanding the non-equilibrium behavior of photoexcited graphene is important for science and applications in detectors, solar ...

  1. Microsoft Word - strickland_abstract

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    quark gluon plasma Dr. Michael Strickland Gettysburg College Abstract: In this talk I will review our theoretical understanding of the dynamics of a non- equilibrium quark ...

  2. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Richland, WA (United States) Idaho Chemical Processing Plant, Idaho Falls, ID ... By using the non-equilibrium Green function method with the slave-boson mean field ...

  3. Nonequilibrium volumetric response of shocked polymers

    SciTech Connect

    Clements, B E

    2009-01-01

    Polymers are well known for their non-equilibrium deviatoric behavior. However, investigations involving both high rate shock experiments and equilibrium measured thermodynamic quantities remind us that the volumetric behavior also exhibits a non-equilibrium response. Experiments supporting the notion of a non-equilibrium volumetric behavior will be summarized. Following that discussion, a continuum-level theory is proposed that will account for both the equilibrium and non-equilibrium response. Upon finding agreement with experiment, the theory is used to study the relaxation of a shocked polymer back towards its shocked equilibrium state.

  4. Communication: Energy-dependent resonance broadening in symmetric...

    Office of Scientific and Technical Information (OSTI)

    Energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach Title: Communication: Energy-depen...

  5. Electronic and spin transport properties of graphene nanoribbon...

    Office of Scientific and Technical Information (OSTI)

    (QUAMBOs), a first-principles tight binding (TB) scheme based on density functional theory (DFT), combined with a non-equilibrium Green's function. For electronic transport,...

  6. Influence of chemical disorder on energy dissipation and defect evolution in concentrated solid solution alloys

    DOE PAGES [OSTI]

    Zhang, Yanwen; Stocks, George Malcolm; Jin, Ke; Lu, Chenyang; Bei, Hongbin; Sales, Brian C.; Wang, Lumin; Béland, Laurent K.; Stoller, Roger E.; Samolyuk, German D.; et al

    2015-10-28

    A long-standing objective in materials research is to understand how energy is dissipated in both the electronic and atomic subsystems in irradiated materials, and how related non-equilibrium processes may affect defect dynamics and microstructure evolution. Here we show that alloy complexity in concentrated solid solution alloys having both an increasing number of principal elements and altered concentrations of specific elements can lead to substantial reduction in the electron mean free path and thermal conductivity, which has a significant impact on energy dissipation and consequentially on defect evolution during ion irradiation. Enhanced radiation resistance with increasing complexity from pure nickel tomore » binary and to more complex quaternary solid solutions is observed under ion irradiation up to an average damage level of 1 displacement per atom. Understanding how materials properties can be tailored by alloy complexity and their influence on defect dynamics may pave the way for new principles for the design of radiation tolerant structural alloys.« less

  7. Tailoring local density of optical states to control emission intensity and anisotropy of quantum dots in hybrid photonic-plasmonic templates

    SciTech Connect

    Indukuri, Chaitanya; Mukherjee, Arnab; Basu, J. K.

    2015-03-30

    We report results of controlled tuning of the local density of states (LDOS) in versatile, flexible, and hierarchical self assembled plasmonic templates. Using 5 nm diameter gold (Au) spherical nanoantenna within a polymer template randomly dispersed with quantum dots, we show how the photoluminescence intensity and lifetime anisotropy of these dots can be significantly enhanced through LDOS tuning. Finite difference time domain simulations corroborate the experimental observations and extend the regime of enhancement to a wider range of geometric and spectral parameters bringing out the versatility of these functional plasmonic templates. It is also demonstrated how the templates act as plasmonic resonators for effectively engineer giant enhancement of the scattering efficiency of these nano antenna embedded in the templates. Our work provides an alternative method to achieve spontaneous emission intensity and anisotropy enhancement with true nanoscale plasmon resonators.

  8. Tailoring the composition of ultrathin, ternary alloy PtRuFe nanowires for the methanol oxidation reaction and formic acid oxidation reaction

    DOE PAGES [OSTI]

    Scofield, Megan E.; Koenigsmann, Christopher; Wang, Lei; Liu, Haiqing; Wong, Stanislaus S.

    2014-11-25

    In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared ‘multifunctional’ ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with binary Pt₇Ru₃ NW, monometallic Pt NW, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication ofmore » crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. Thus, these NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.« less

  9. Tailoring Vacancies Far Beyond Intrinsic Levels Changes the Carrier Type and Optical Response in Monolayer MoSe 2-x Crystals

    DOE PAGES [OSTI]

    Mahjouri-Samani, Masoud; Liang, Liangbo; Oyedele, Akinola; Kim, Yong-Sung; Tian, Mengkun; Cross, Nicholas; Wang, Kai; Lin, Ming-Wei; Boulesbaa, Abdelaziz; Rouleau, Christopher M.; et al

    2016-07-14

    Defect engineering has been a critical step in controlling the transport characteristics of electronic devices, and the ability to create, tune, and annihilate defects is essential to enable the range of next-generation devices. Whereas defect formation has been well-demonstrated in three-dimensional semiconductors, similar exploration of the heterogeneity in atomically thin two-dimensional semiconductors and the link between their atomic structures, defects, and properties has not yet been extensively studied. In this paper, we demonstrate the growth of MoSe2–x single crystals with selenium (Se) vacancies far beyond intrinsic levels, up to ~20%, that exhibit a remarkable transition in electrical transport properties frommore » n- to p-type character with increasing Se vacancy concentration. A new defect-activated phonon band at ~250 cm-1 appears, and the A1g Raman characteristic mode at 240 cm-1 softens toward ~230 cm-1 which serves as a fingerprint of vacancy concentration in the crystals. We show that post-selenization using pulsed laser evaporated Se atoms can repair Se-vacant sites to nearly recover the properties of the pristine crystals. Finally, first-principles calculations reveal the underlying mechanisms for the corresponding vacancy-induced electrical and optical transitions.« less

  10. Tailoring the surface properties of LiNi0.4Mn0.4Co0.2O₂ by...

    Office of Scientific and Technical Information (OSTI)

    Authors: Wolff-Goodrich, Silas 1 ; Xin, Huolin L. 2 ; Lin, Feng 3 ; Markus, Isaac M. 1 ; Nordlund, Dennis 4 ; Asta, Mark 1 ; Doeff, Marca M. 3 + Show Author ...

  11. Bandgap tailoring of in-situ nitrogen-doped TiO₂ sputtered films intended for electrophotocatalytic applications under solar light

    SciTech Connect

    Delegan, N.; El Khakani, M. A.; Daghrir, R.; Drogui, P.

    2014-10-21

    We report on a reactive RF-sputtering process permitting the in-situ nitrogen doping of TiO₂ films in order to shift their photoactivity from UV to visible range. By carefully controlling the relative nitrogen-to-argon mass flow rate ratio (within the 0%–25% range) in the sputter deposition chamber, TiO₂:N films were grown with nitrogen contents ranging from 0 to 6.2 at. %, as determined by high-resolution X-ray spectroscopy measurements. A systematic investigation of the crystalline structure of the TiO₂:N films, as a function of their N content, revealed that low N contents (0.2–0.3 at. %) induce crystallization in the rutile phase while higher N contents (≥1.4 at. %) were accompanied with the recovery of the anatase structure with an average crystallite size of ~35 nm. By using both UV-Vis absorption and spectroscopic ellipsometry measurements, we were able to quantitatively determine the bandgap (E{sub g}) variation of the TiO₂:N films as a function of their N content. Thus, we have demonstrated that the E{sub g} of the TiO₂:N films effectively narrows from 3.2 eV down to a value as low as ~2.3 eV for the optimal N doping concentration of 3.4 at. % (higher N incorporation does not translate into further red shifting of the TiO₂:N films' E{sub g}). The photoactivity of the TiO₂:N films under visible light was confirmed through electro-photocatalytic decomposition of chlortetracycline (CTC, an emerging water pollutant) under standard 1.5AM solar radiation. Thus, CTC degradation efficiencies of up to 98% were achieved with 2 hours process cycles under simulated solar light. Moreover, the electro-photocatalytic performance of the TiO₂:N films is shown to be directly correlated to their optoelectronic properties (namely their bandgap narrowing).

  12. Plasma treatment of porous SiN{sub x}:H films for the fabrication of porous-dense multilayer optical filters with tailored interfaces

    SciTech Connect

    Vernhes, R.; Amassian, A.; Klemberg-Sapieha, J.E.; Martinu, L.

    2006-06-01

    Porous and dense silicon nitride films with low (1.58) and high (1.88) refractive indices were prepared by using successively microwave and radio frequency (rf) plasma-enhanced chemical vapor deposition. Surface treatments were performed on porous layers using argon and nitrogen rf plasmas in order to densify and flatten their surface, and hence to obtain an abrupt transition between porous and dense films. The processes during deposition and interface treatment were studied by in situ real-time spectroscopic ellipsometry as well as by other characterization techniques. We show that besides the densification effect, preferential sputtering and annealing phenomena occur during plasma treatments at high bias (|V{sub B}{sup treat}|>400 V), leading to silicon enrichment at the film surface and chemical stabilization of the film bulk. Using atomic force microscopy, we observed a significant reduction of the thickness of the surface roughness layer after treatment for single layers ({approx_equal}70% reduction) and multilayer stacks ({approx_equal}60% reduction). Porous-dense Fabry-Perot filters were fabricated using this approach that led to both enhanced optical performance due to minimized interface thickness and improved environmental stability.

  13. Record figure of merit values of highly stoichiometric Sb2Te3 porous bulk synthesized from tailor-made molecular precursors in ionic liquids

    DOE PAGES [OSTI]

    Heimann, Stefan; Schulz, Stephan; Schaumann, Julian; Mudring, Anja; Stötzel, Julia; Maculewicz, Franziska; Schierning, Gabi

    2015-08-06

    We report on the synthesis of Sb2Te3 nanoparticles with record-high figure of merit values of up to 1.5. The central thermoelectric parameters, electrical conductivity, thermal conductivity and Seebeck coefficient, were independently optimized. Critical influence of porosity for the fabrication of highly efficient thermoelectric materials is firstly demonstrated, giving a strong guidance for the optimization of other thermoelectric materials.

  14. TAILORING X-RAY BEAM ENERGY SPECTRUM TO ENHANCE IMAGE QUALITY OF NEW RADIOGRAPHY CONTRAST AGENTS BASED ON GD OR OTHER LANTHANIDES.

    SciTech Connect

    DILMANIAN,F.A.; WEINMANN,H.J.; ZHONG,Z.; BACARIAN,T.; RIGON,L.; BUTTON,T.M.; REN,B.; WU,X.Y.; ZHONG,N.; ATKINS,H.L.

    2001-02-17

    Gadovist, a 1.0-molar Gd contrast agent from Schering AG, Berlin Germany, in use in clinical MPI in Europe, was evaluated as a radiography contrast agent. In a collaboration with Brookhaven National Laboratory (BNL), Schering AG is developing several such lanthanide-based contrast agents, while BNL evaluates them using different x-my beam energy spectra. These energy spectra include a ''truly'' monochromatic beam (0.2 keV energy bandwidth) from the National Synchrotron Light Source (NSLS), BNL, tuned above the Gd K-edge, and x-ray-tube beams from different kVp settings and beam filtrations. Radiographs of rabbits' kidneys were obtained with Gadovist at the NSLS. Furthermore, a clinical radiography system was used for imaging rabbits' kidneys comparing Gadovist and Conray, an iodinated contrast agent. The study, using 74 kVp and standard Al beam filter for Conray and 66 kVp and an additional 1.5 mm Cu beam filter for Gadovist, produced comparable images for Gadovist and Conray; the injection volumes were the same, while the radiation absorbed dose for Gadovist was slightly smaller. A bent-crystal silicon monochromator operating in the Laue diffraction mode was developed and tested with a conventional x-ray tube beam; it narrows the energy spectrum to about 4 keV around the anode tungsten's Ku line. Preliminary beam-flux results indicate that the method could be implemented in clinical CT if x-ray tubes with {approximately} twice higher output become available.

  15. Tailoring the composition of ultrathin, ternary alloy PtRuFe nanowires for the methanol oxidation reaction and formic acid oxidation reaction

    SciTech Connect

    Scofield, Megan E.; Koenigsmann, Christopher; Wang, Lei; Lui, Haiqing; Wong, Stanislaus S.

    2014-11-25

    In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared multifunctional ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with binary Pt?Ru? NW, monometallic Pt NW, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication of crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. These NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.

  16. Numerical modeling of heat-transfer and the influence of process parameters on tailoring the grain morphology of IN718 in electron beam additive manufacturing

    DOE PAGES [OSTI]

    Raghavan, Narendran; Dehoff, Ryan; Pannala, Sreekanth; Simunovic, Srdjan; Kirka, Michael; Turner, John; Carlson, Neil; Babu, Sudarsanam S.

    2016-04-26

    The fabrication of 3-D parts from CAD models by additive manufacturing (AM) is a disruptive technology that is transforming the metal manufacturing industry. The correlation between solidification microstructure and mechanical properties has been well understood in the casting and welding processes over the years. This paper focuses on extending these principles to additive manufacturing to understand the transient phenomena of repeated melting and solidification during electron beam powder melting process to achieve site-specific microstructure control within a fabricated component. In this paper, we have developed a novel melt scan strategy for electron beam melting of nickel-base superalloy (Inconel 718) andmore » also analyzed 3-D heat transfer conditions using a parallel numerical solidification code (Truchas) developed at Los Alamos National Laboratory. The spatial and temporal variations of temperature gradient (G) and growth velocity (R) at the liquid-solid interface of the melt pool were calculated as a function of electron beam parameters. By manipulating the relative number of voxels that lie in the columnar or equiaxed region, the crystallographic texture of the components can be controlled to an extent. The analysis of the parameters provided optimum processing conditions that will result in columnar to equiaxed transition (CET) during the solidification. Furthermore, the results from the numerical simulations were validated by experimental processing and characterization thereby proving the potential of additive manufacturing process to achieve site-specific crystallographic texture control within a fabricated component.« less

  17. Tailoring the composition of ultrathin, ternary alloy PtRuFe nanowires for the methanol oxidation reaction and formic acid oxidation reaction

    SciTech Connect

    Scofield, Megan E.; Koenigsmann, Christopher; Wang, Lei; Liu, Haiqing; Wong, Stanislaus S.

    2014-11-25

    In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared multifunctional ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with binary Pt?Ru? NW, monometallic Pt NW, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication of crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. Thus, these NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.

  18. Tailoring characteristic thermal stability of Ni-Au binary nanocrystals via structure and composition engineering: theoretical insights into structural evolution and atomic inter-diffusion

    SciTech Connect

    Li, Bangquan; Wang, Hailong; Xing, Guozhong; Wang, Rongming E-mail: rmwang@ustb.edu.cn

    2014-11-15

    We report on the structural evolution and atomic inter-diffusion characteristics of the bimetallic Ni-Au nanocrystals (NCs) by molecular dynamics simulations studies. Our results reveal that the thermal stability dynamics of Ni-Au NCs strongly depends on the atomic configurations. By engineering the structural construction with Ni:Au = 1:1 atomic composition, compared with core-shell Au@Ni and alloy NCs, the melting point of core-shell Ni@Au NCs is significantly enhanced up to 1215 K. Unexpectedly, with atomic ratio of Au:Ni= 1:9, the melting process initiates from the atoms in the shell of Ni@Au and alloy NCs, while starts from the core of Au@Ni NCs. The corresponding features and evolution process of structural motifs, mixing and segregation are illustrated via a series of dynamic simulations videos. Moreover, our results revealed that the face centered cubic phase Au{sub 0.75}Ni{sub 0.25} favorably stabilizes in NCs form but does not exist in the bulk counterpart, which elucidates the anomalies of previously reported experimental results on such bimetallic NCs.

  19. Nonequilibrium Thermoelectrics: Low-Cost, High-Performance Materials...

    Office of Scientific and Technical Information (OSTI)

    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 ...

  20. May

    Office of Scientific and Technical Information (OSTI)

    By using the non-equilibrium Green function method with the slave-boson mean field ... But for the undoped graphene, the Kondo phase only exists if the adatom's energy level is ...

  1. Search for: kondo effect | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    By using the non-equilibrium Green function method with the slave-boson mean field ... But for the undoped graphene, the Kondo phase only exists if the adatom's energy level is ...

  2. Scanning tunneling spectroscopy of a magnetic atom on graphene...

    Office of Scientific and Technical Information (OSTI)

    By using the non-equilibrium Green function method with the slave-boson mean field ... But for the undoped graphene, the Kondo phase only exists if the adatom's energy level is ...

  3. Scanning tunneling spectroscopy of a magnetic atom on graphene...

    Office of Scientific and Technical Information (OSTI)

    Visit OSTI to utilize additional information resources in energy science and technology. A ... By using the non-equilibrium Green function method with the slave-boson mean field ...

  4. Reversibility and criticality in amorphous solids (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    We compare this non-equilibrium critical behaviour to the prevailing concept of a 'front depinning' transition that has been used to describe steady-state avalanche behaviour in ...

  5. Scanning tunneling spectroscopy of a magnetic atom on graphene...

    Office of Scientific and Technical Information (OSTI)

    In this study, the Kondo effect in the system consisting of a magnetic adatom on the graphene is studied. By using the non-equilibrium Green function method with the slave-boson ...

  6. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... By using the non-equilibrium Green function method with the slave-boson mean field approximation, the local density of state (LDOS) and the conductance are calculated. For a doped ...

  7. CX-004918: Categorical Exclusion Determination

    Energy.gov [DOE]

    Sheetak -Non-Equilibrium Asymmetric Thermoelectric DevicesCX(s) Applied: B3.6Date: 08/10/2010Location(s): Austin, TexasOffice(s): Advanced Research Projects Agency - Energy

  8. Non-local thermodynamic equilibrium effects on isentropic coefficient in argon and helium thermal plasmas

    SciTech Connect

    Sharma, Rohit; Singh, Kuldip

    2014-03-15

    In the present work, two cases of thermal plasma have been considered; the ground state plasma in which all the atoms and ions are assumed to be in the ground state and the excited state plasma in which atoms and ions are distributed over various possible excited states. The variation of Z?, frozen isentropic coefficient and the isentropic coefficient with degree of ionization and non-equilibrium parameter ?(= T{sub e}/T{sub h}) has been investigated for the ground and excited state helium and argon plasmas at pressures 1?atm, 10?atm, and 100?atm in the temperature range from 6000?K to 60?000?K. For a given value of non-equilibrium parameter, the relationship of Z? with degree of ionization does not show any dependence on electronically excited states in helium plasma whereas in case of argon plasma this dependence is not appreciable till degree of ionization approaches 2. The minima of frozen isentropic coefficient shifts toward lower temperature with increase of non-equilibrium parameter for both the helium and argon plasmas. The lowering of non-equilibrium parameter decreases the frozen isentropic coefficient more emphatically in helium plasma at high pressures in comparison to argon plasma. The increase of pressure slightly reduces the ionization range over which isentropic coefficient almost remains constant and it does not affect appreciably the dependence of isentropic coefficient on non-equilibrium parameter.

  9. Tailoring the surface properties of LiNi0.4Mn0.4Co0.2O₂ by titanium substitution for improved high voltage cycling performance

    DOE PAGES [OSTI]

    Wolff-Goodrich, Silas; Xin, Huolin L.; Lin, Feng; Markus, Isaac M.; Nordlund, Dennis; Asta, Mark; Doeff, Marca M.

    2015-07-30

    The present research aims to provide insights into the behavior of LiNi0.4Mn0.4Co0.2O2 (NMC442) and LiNi0.4Mn0.4Co0.2O₂ (NMC442-Ti02) cathode materials under galvanostatic cycling to high potentials, in the context of previous work which predicted that Ti-substituted variants should deliver higher capacities and exhibit better cycling stability than the unsubstituted compounds. It is found that NMC cathodes containing Ti show equivalent capacity fading but greater specific capacity than those without Ti in the same potential range. When repeatedly charged to the same degree of delithiation, NMC cathodes containing Ti showed better capacity retention. Soft x-ray absorption spectroscopy (XAS) spectra for Mn and Comore » indicated increased reduction in these elements for NMC cathodes without Ti, indicating that the substitution of Ti for Co acts to suppress the formation of a high impedance rock salt phase at the surface of NMC cathode particles. The results of this study validate the adoption of a facile change to existing NMC chemistries to improve cathode capacity retention under high voltage cycling conditions.« less

  10. Tailoring the surface properties of LiNi0.4Mn0.4Co0.2O₂ by titanium substitution for improved high voltage cycling performance

    SciTech Connect

    Wolff-Goodrich, Silas; Xin, Huolin L.; Lin, Feng; Markus, Isaac M.; Nordlund, Dennis; Asta, Mark; Doeff, Marca M.

    2015-07-30

    The present research aims to provide insights into the behavior of LiNi0.4Mn0.4Co0.2O2 (NMC442) and LiNi0.4Mn0.4Co0.2O₂ (NMC442-Ti02) cathode materials under galvanostatic cycling to high potentials, in the context of previous work which predicted that Ti-substituted variants should deliver higher capacities and exhibit better cycling stability than the unsubstituted compounds. It is found that NMC cathodes containing Ti show equivalent capacity fading but greater specific capacity than those without Ti in the same potential range. When repeatedly charged to the same degree of delithiation, NMC cathodes containing Ti showed better capacity retention. Soft x-ray absorption spectroscopy (XAS) spectra for Mn and Co indicated increased reduction in these elements for NMC cathodes without Ti, indicating that the substitution of Ti for Co acts to suppress the formation of a high impedance rock salt phase at the surface of NMC cathode particles. The results of this study validate the adoption of a facile change to existing NMC chemistries to improve cathode capacity retention under high voltage cycling conditions.

  11. Record figure of merit values of highly stoichiometric Sb2Te3 porous bulk synthesized from tailor-made molecular precursors in ionic liquids

    SciTech Connect

    Heimann, Stefan; Schulz, Stephan; Schaumann, Julian; Mudring, Anja; Stötzel, Julia; Maculewicz, Franziska; Schierning, Gabi

    2015-08-06

    We report on the synthesis of Sb2Te3 nanoparticles with record-high figure of merit values of up to 1.5. The central thermoelectric parameters, electrical conductivity, thermal conductivity and Seebeck coefficient, were independently optimized. Critical influence of porosity for the fabrication of highly efficient thermoelectric materials is firstly demonstrated, giving a strong guidance for the optimization of other thermoelectric materials.

  12. Influences of ureaglycerol mixtures as mixed mesopore-controlling agents on tailoring physicochemical properties and photocatalytic H{sub 2} production activity of solgel-derived mesoporous-assembled TiO{sub 2} nanocrystals

    SciTech Connect

    Sreethawong, Thammanoon; Ngamsinlapasathian, Supachai; Yoshikawa, Susumu

    2013-01-15

    Graphical abstract: Display Omitted Highlights: ? Mesoporous-assembled TiO{sub 2} nanocrystals were synthesized by modified solgel process. ? Ureaglycerol mixtures were applied as mixed mesopore-controlling agents. ? Urea and glycerol contents affected physicochemical properties of synthesized TiO{sub 2}. ? Photocatalytic H{sub 2} production activity also depended on urea and glycerol contents. ? 75 mol% urea and 25 mol% glycerol yielded the most photocatalytically active TiO{sub 2}. -- Abstract: In this work, the mesoporous-assembled TiO{sub 2} nanocrystal photocatalysts were successfully synthesized by a solgel process with the aid of ureaglycerol mixtures used as mixed mesopore-controlling agents. The photocatalytic activity of the synthesized mesoporous-assembled TiO{sub 2} nanocrystal photocatalysts was investigated for hydrogen production from the water splitting reaction using methanol as a hole scavenger under UV light irradiation. The synthesized TiO{sub 2} nanocrystal photocatalysts were systematically characterized by TGDTA, N{sub 2} adsorptiondesorption, SEM, high resolution TEM, and XRD analyses. The characterization results showed that the well-controlled contents of urea and glycerol in a ureaglycerol mixture at 75 mol% urea and 25 mol% glycerol resulted in not only the most highly porous network (i.e. the highest specific surface area and total pore volume, and the smallest mean mesopore diameter), but also the smallest crystallite size of the synthesized TiO{sub 2} nanocrystal photocatalyst. The photocatalytic reaction results, hence, revealed a much superior photocatalytic hydrogen production activity of the mesoporous-assembled TiO{sub 2} nanocrystal synthesized with 75 mol% urea and 25 mol% glycerol to the other synthesized TiO{sub 2} nanocrystals, also being much higher than those of the commercially available P-25 TiO{sub 2} and ST-01 TiO{sub 2} powders.

  13. Tailoring the surface properties of LiNi0.4Mn0.4Co0.2O? by titanium substitution for improved high voltage cycling performance

    SciTech Connect

    Wolff-Goodrich, Silas; Xin, Huolin L.; Lin, Feng; Markus, Isaac M.; Nordlund, Dennis; Asta, Mark; Doeff, Marca M.

    2015-07-30

    The present research aims to provide insights into the behavior of LiNi0.4Mn0.4Co0.2O2 (NMC442) and LiNi0.4Mn0.4Co0.2O? (NMC442-Ti02) cathode materials under galvanostatic cycling to high potentials, in the context of previous work which predicted that Ti-substituted variants should deliver higher capacities and exhibit better cycling stability than the unsubstituted compounds. It is found that NMC cathodes containing Ti show equivalent capacity fading but greater specific capacity than those without Ti in the same potential range. When repeatedly charged to the same degree of delithiation, NMC cathodes containing Ti showed better capacity retention. Soft x-ray absorption spectroscopy (XAS) spectra for Mn and Co indicated increased reduction in these elements for NMC cathodes without Ti, indicating that the substitution of Ti for Co acts to suppress the formation of a high impedance rock salt phase at the surface of NMC cathode particles. The results of this study validate the adoption of a facile change to existing NMC chemistries to improve cathode capacity retention under high voltage cycling conditions.

  14. (Magneto)caloric refrigeration: Is there light at the end of the tunnel?

    DOE PAGES [OSTI]

    Pecharsky, Vitalij K.; Cui, Jun; Johnson, Duane D.

    2016-07-11

    Here, caloric cooling and heat pumping rely on reversible thermal effects triggered in solids by magnetic, electric or stress fields. In the recent past, there have been several successful demonstrations of using first-order phase transition materials in laboratory cooling devices based on both the giant magnetocaloric and elastocaloric effects. All such materials exhibit non-equilibrium behaviours when driven through phase transformations by corresponding fields. Common wisdom is that non-equilibrium states should be avoided; yet, as we show using a model material exhibiting a giant magnetocaloric effect, non-equilibrium phase-separated states offer a unique opportunity to achieve uncommonly large caloric effects by verymore » small perturbations of the driving field(s).« less

  15. An approximate framework for quantum transport calculation with model order reduction

    SciTech Connect

    Chen, Quan; Li, Jun; Yam, Chiyung; Zhang, Yu; Wong, Ngai; Chen, Guanhua

    2015-04-01

    A new approximate computational framework is proposed for computing the non-equilibrium charge density in the context of the non-equilibrium Green's function (NEGF) method for quantum mechanical transport problems. The framework consists of a new formulation, called the X-formulation, for single-energy density calculation based on the solution of sparse linear systems, and a projection-based nonlinear model order reduction (MOR) approach to address the large number of energy points required for large applied biases. The advantages of the new methods are confirmed by numerical experiments.

  16. Relaxation dynamics in correlated quantum dots

    SciTech Connect

    Andergassen, S.; Schuricht, D.; Pletyukhov, M.; Schoeller, H.

    2014-12-04

    We study quantum many-body effects on the real-time evolution of the current through quantum dots. By using a non-equilibrium renormalization group approach, we provide analytic results for the relaxation dynamics into the stationary state and identify the microscopic cutoff scales that determine the transport rates. We find rich non-equilibrium physics induced by the interplay of the different energy scales. While the short-time limit is governed by universal dynamics, the long-time behavior features characteristic oscillations as well as an interplay of exponential and power-law decay.

  17. Entropy in an Arc Plasma Source

    SciTech Connect

    Kaminska, A.; Dudeck, M

    2008-03-19

    The entropy properties in a D.C. argon arc plasma source are studied. The local thermodynamical entropy relations are established for a set of uniform sub-systems (Ar, Ar{sup +}, e) in order to deduce the entropy balance equation in presence of dissipative effects and in the case of a thermal non equilibrium. Phenomenological linear laws are deduced in near equilibrium situation. The flow parameters inside the plasma source are calculated by a Navier-Stokes fluid description taking into account a thermal local non equilibrium. The entropy function is calculated in the plasma source using the values of the local variables obtained from the numerical code.

  18. Upscaling of the waterflood reservoir properties on the core level: Laboratory study, macro and micro modelling

    SciTech Connect

    Bedrikovetsky, P.G.; Polyanin, A.D.; Zhurov, A.I.; Potsch, K.T.

    1995-10-01

    The aim of the paper is to develop a mathematical model for waterflooding at high velocities in short cores under laboratory conditions. The model is based on the theory of non-equilibrium two-phase flow in a porous medium. The asymptotic solution includes the capillary pressure and non-equilibrium effects. It allows for determining an expression for he stabilized zone, which leads to an optimal core length and an optimal displacement velocity. With these parameters it is possible to plan waterflooding tests for determining the relative phase permeabilities with a given accuracy.

  19. Towards breaking temperature equilibrium in multi-component Eulerian schemes

    SciTech Connect

    Grove, John W; Masser, Thomas

    2009-01-01

    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.

  20. Recovery Act, EFRC Project: Solar Energy Conversion in Complex Materials (SECCM)

    SciTech Connect

    Green, Peter F.

    2015-06-25

    The goal of the Center was to design and to synthesize new materials for high efficiency photovoltaic (PV) and thermoelectric (TE) devices, predicated on new fundamental insights into equilibrium and non-equilibrium processes, including quantum phenomena, that occur in materials over various spatial and temporal scales.

  1. Supersonic Argon Flow In An Arc Plasma Source

    SciTech Connect

    Izrar, B.; Dudeck, M.; Andre, P.; Elchinger, M. F.; Aubreton, J.

    2006-01-15

    The plasma properties inside a D.C. arc-jet operating with argon is analysed by means of a continuum description taking into account non equilibrium ionization processes and dissipative effects. The relaxation of the different physical processes inside the nozzle and the evolution of the Mach number are aanalysed.

  2. Gas-kinetic unified algorithm for hypersonic flows covering various flow regimes solving Boltzmann model equation in nonequilibrium effect

    SciTech Connect

    Li, Zhihui; Ma, Qiang; Wu, Junlin; Jiang, Xinyu; Zhang, Hanxin

    2014-12-09

    Based on the Gas-Kinetic Unified Algorithm (GKUA) directly solving the Boltzmann model equation, the effect of rotational non-equilibrium is investigated recurring to the kinetic Rykov model with relaxation property of rotational degrees of freedom. The spin movement of diatomic molecule is described by moment of inertia, and the conservation of total angle momentum is taken as a new Boltzmann collision invariant. The molecular velocity distribution function is integrated by the weight factor on the internal energy, and the closed system of two kinetic controlling equations is obtained with inelastic and elastic collisions. The optimization selection technique of discrete velocity ordinate points and numerical quadrature rules for macroscopic flow variables with dynamic updating evolvement are developed to simulate hypersonic flows, and the gas-kinetic numerical scheme is constructed to capture the time evolution of the discretized velocity distribution functions. The gas-kinetic boundary conditions in thermodynamic non-equilibrium and numerical procedures are studied and implemented by directly acting on the velocity distribution function, and then the unified algorithm of Boltzmann model equation involving non-equilibrium effect is presented for the whole range of flow regimes. The hypersonic flows involving non-equilibrium effect are numerically simulated including the inner flows of shock wave structures in nitrogen with different Mach numbers of 1.5-Ma-25, the planar ramp flow with the whole range of Knudsen numbers of 0.0009-Kn-10 and the three-dimensional re-entering flows around tine double-cone body.

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

    SciTech Connect

    Cappelli, Mark; Mungal, M Godfrey

    2014-10-28

    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.

  4. CX-000428: Categorical Exclusion Determination

    Energy.gov [DOE]

    Risk Assessment and Monitoring of Stored of Non-Equilibrium Conditions on Carbon Dioxide Stored in Organic RocksCX(s) Applied: B3.1Date: 12/11/2009Location(s): Carbondale, IllinoisOffice(s): Fossil Energy, National Energy Technology Laboratory

  5. Propulsion Materials

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    17257 - Materials for Advanced Turbocharger Designs ......- Tailored Materials for Improved Internal Combustion Engine Efficiency ...... 82 ...

  6. Genetics in the courts

    SciTech Connect

    Coyle, Heather; Drell, Dan

    2000-12-01

    Various: (1)TriState 2000 Genetics in the Courts (2) Growing impact of the new genetics on the courts (3)Human testing (4) Legal analysis - in re G.C. (5) Legal analysis - GM ''peanots'', and (6) Legal analysis for State vs Miller

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

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    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

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

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    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

  9. CI-ON Ex A (Rev. 0.4, 8/20/14) Exhibit A General Conditions

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    4, 8/20/14) Exhibit A General Conditions Page 1 of 13 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-A1 COMMERCIAL ITEMS (Aug 2014) ........................................................................................... 2 GC-1B DEFINITIONS (Mar 2012) ......................................................................................................... 4 GC-2B CORRESPONDENCE AND SUBCONTRACT INTERPRETATION (Jan 2010) ....................... 4 GC-5 NOTICE TO

  10. CI-ON Ex A (Rev. 0.5, 3/6/15) Exhibit A General Conditions

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    5, 3/6/15) Exhibit A General Conditions Page 1 of 14 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-A1 COMMERCIAL ITEMS (Aug 2014) ........................................................................................... 2 GC-1B DEFINITIONS (Mar 2012) ......................................................................................................... 4 GC-2B CORRESPONDENCE AND SUBCONTRACT INTERPRETATION (Jan 2010) ....................... 4 GC-5 NOTICE TO

  11. CI-ON Ex A (Rev. 0.7, 11/9/15) Exhibit A General Conditions

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    7, 11/9/15) Exhibit A General Conditions Page 1 of 14 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-A1 COMMERCIAL ITEMS (May 2015) ....................................................................................... 2 GC-1B DEFINITIONS (Mar 2012) ..................................................................................................... 4 GC-2B CORRESPONDENCE AND SUBCONTRACT INTERPRETATION (Jan 2010) ...................... 4 GC-5 NOTICE TO PROCEED (Jul

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

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    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

  13. Attempt to measure magnetic hyperfine fields in metallic thin wires under spin Hall conditions using synchrotron-radiation Mssbauer spectroscopy

    SciTech Connect

    Mibu, K. Tanaka, M. A.; Mitsui, T.; Masuda, R.; Kitao, S.; Kobayashi, Y.; Seto, M.; Yoda, Y.

    2015-05-07

    Measurement of the magnetic hyperfine fields in metallic thin wires under spin Hall conditions was attempted using the emerging technique, synchrotron-radiation Mssbauer spectroscopy. A Mssbauer probe layer of {sup 57}Fe (0.2?nm), {sup 57}Fe (0.6?nm), or {sup 119}Sn (0.6?nm) was embedded as an electron spin detector near the surfaces of V, Au, Pt, and {sup 56}Fe wires. The magnitudes of the magnetic hyperfine fields at the {sup 57}Fe and {sup 119}Sn nuclear sites that could be enhanced by non-equilibrium conduction-electron spin polarization were measured both without and with the application of an electric current along the wire. Changes in the Mssbauer spectra were not clearly observed, indicating that the magnetic hyperfine field induced by non-equilibrium spin polarization is smaller than the detection limit at least for the measured systems and conditions.

  14. Terahertz Spectroscopy of Low-Dimensional Nanomaterials: Nonlinear Emission and Ultrafast Electrodynamics

    DOE PAGES [OSTI]

    Luo, Liang; Wang, Jigang

    2016-01-01

    Nonlinear and non-equilibrium properties of low-dimensional quantum materials are fundamental in nanoscale science yet transformative in nonlinear imaging/photonic technology today. These have been poorly addressed in many nano-materials despite of their well-established equilibrium optical and transport properties. The development of ultrafast terahertz (THz) sources and nonlinear spectroscopy tools facilitates understanding these issues and reveals a wide range of novel nonlinear and quantum phenomena that are not expected in bulk solids or atoms. In this paper, we discuss our recent discoveries in two model photonic and electronic nanostructures to solve two outstanding questions: (1) how to create nonlinear broadband terahertz emittersmore » using deeply subwavelength nanoscale meta-atom resonators? (2) How to access one-dimensional (1D) dark excitons and their non-equilibrium correlated states in single-walled carbon nanotubes (SWMTs)?« less

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

    SciTech Connect

    Li, Qiang

    2009-04-30

    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.

  16. Fluctuational electrodynamics of hyperbolic metamaterials

    SciTech Connect

    Guo, Yu; Jacob, Zubin

    2014-06-21

    We give a detailed account of equilibrium and non-equilibrium fluctuational electrodynamics of hyperbolic metamaterials. We show the unifying aspects of two different approaches; one utilizes the second kind of fluctuation dissipation theorem and the other makes use of the scattering method. We analyze the near-field of hyperbolic media at finite temperatures and show that the lack of spatial coherence can be attributed to the multi-modal nature of super-Planckian thermal emission. We also adopt the analysis to phonon-polaritonic super-lattice metamaterials and describe the regimes suitable for experimental verification of our predicted effects. The results reveal that far-field thermal emission spectra are dominated by epsilon-near-zero and epsilon-near-pole responses as expected from Kirchoff's laws. Our work should aid both theorists and experimentalists to study complex media and engineer equilibrium and non-equilibrium fluctuations for applications in thermal photonics.

  17. Terahertz Spectroscopy of Low-Dimensional Nanomaterials: Nonlinear Emission and Ultrafast Electrodynamics

    SciTech Connect

    Luo, Liang; Wang, Jigang

    2016-01-01

    Nonlinear and non-equilibrium properties of low-dimensional quantum materials are fundamental in nanoscale science yet transformative in nonlinear imaging/photonic technology today. These have been poorly addressed in many nano-materials despite of their well-established equilibrium optical and transport properties. The development of ultrafast terahertz (THz) sources and nonlinear spectroscopy tools facilitates understanding these issues and reveals a wide range of novel nonlinear and quantum phenomena that are not expected in bulk solids or atoms. In this paper, we discuss our recent discoveries in two model photonic and electronic nanostructures to solve two outstanding questions: (1) how to create nonlinear broadband terahertz emitters using deeply subwavelength nanoscale meta-atom resonators? (2) How to access one-dimensional (1D) dark excitons and their non-equilibrium correlated states in single-walled carbon nanotubes (SWMTs)?

  18. Complexity reduction of collisional-radiative kinetics for atomic plasma

    SciTech Connect

    Le, Hai P.; Karagozian, Ann R.; Cambier, Jean-Luc

    2013-12-15

    Thermal non-equilibrium processes in partially ionized plasmas can be most accurately modeled by collisional-radiative kinetics. This level of detail is required for an accurate prediction of the plasma. However, the resultant system of equations can be prohibitively large, making multi-dimensional and unsteady simulations of non-equilibrium radiating plasma particularly challenging. In this paper, we present a scheme for model reduction of the collisional-radiative kinetics, by combining energy levels into groups and deriving the corresponding macroscopic rates for all transitions. Although level-grouping is a standard approach to this type of problem, we provide here a mechanism for achieving higher-order accuracy by accounting for the level distribution within a group. The accuracy and benefits of the scheme are demonstrated for the generic case of atomic hydrogen by comparison with the complete solution of the master rate equations and other methods.

  19. Quarkyonic Matter and Quark Number Scaling of Elliptic Flow

    SciTech Connect

    Csernai, L. P.; Zschocke, S.; Horvat, Sz.; Cheng Yun; Mishustin, I. N.

    2011-05-23

    The constituent quark number scaling of elliptic flow is studied in a non-equilibrium hadronization and freeze-out model with rapid dynamical transition from ideal, deconfined and chirally symmetric Quark Gluon Plasma, to final non-interacting hadrons. In this transition a Bag model of constituent quarks is considered, where the quarks gain constituent quark mass while the background Bag-field breaks up and vanishes. The constituent quarks then recombine into simplified hadron states, while chemical, thermal and flow equilibrium break down one after the other. In this scenario the resulting temperatures and flow velocities of baryons and mesons are different. Using a simplified few source model of the elliptic flow, we are able to reproduce the constituent quark number scaling, with assumptions on the details of the non-equilibrium processes.

  20. Optical-phonon-mediated photocurrent in terahertz quantum-well photodetectors

    SciTech Connect

    Gu, L. L.; Guo, X. G. Fu, Z. L.; Wan, W. J.; Zhang, R.; Tan, Z. Y.; Cao, J. C.

    2015-03-16

    Strong and sharp photocurrent peak at longitudinal optical (LO) phonon frequency (8.87 THz) is found in GaAs/(Al,Ga)As terahertz quantum-well photodetectors (QWPs). Two mesa-structure terahertz QWPs with and without one-dimensional metal grating are fabricated to investigate the behavior of such photoresponse peak. The experimental and simulation results indicate that the photocurrent peak originates from a two-step process. First, at the LO phonon frequency, a large number of non-equilibrium LO phonons are excited by the incident electromagnetic field, and the electromagnetic energy is localized and enhanced in the thin multi-quantum-well layer. Second, through the Frohlich interaction, the localized electrons are excited to continuum states by absorbing the non-equilibrium LO phonons, which leads to the strong photoresponse peak. This finding is useful for exploring strong light-matter interaction and realizing high sensitive terahertz photodetectors.

  1. Repeated interactions in open quantum systems

    SciTech Connect

    Bruneau, Laurent; Joye, Alain; Merkli, Marco

    2014-07-15

    Analyzing the dynamics of open quantum systems has a long history in mathematics and physics. Depending on the system at hand, basic physical phenomena that one would like to explain are, for example, convergence to equilibrium, the dynamics of quantum coherences (decoherence) and quantum correlations (entanglement), or the emergence of heat and particle fluxes in non-equilibrium situations. From the mathematical physics perspective, one of the main challenges is to derive the irreversible dynamics of the open system, starting from a unitary dynamics of the system and its environment. The repeated interactions systems considered in these notes are models of non-equilibrium quantum statistical mechanics. They are relevant in quantum optics, and more generally, serve as a relatively well treatable approximation of a more difficult quantum dynamics. In particular, the repeated interaction models allow to determine the large time (stationary) asymptotics of quantum systems out of equilibrium.

  2. CoverSheet

    Office of Scientific and Technical Information (OSTI)

    interference of the light that is relevant for energy applications: visible and infra-red wavelengths. Tailoring the meso-structure, one can tailor the laws of physics (as far...

  3. Chemical Physics | The Ames Laboratory

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Physics FWP/Project Description: Project Leader(s): James Evans, Mark Gordon Principal Investigators: James Evans, Mark Gordon, Klaus Ruedenberg, Theresa Windus Key Scientific Personnel: Da-Jiang Liu, Michael Schmidt. The theoretical Chemical Physics program at Ames Laboratory supports integrated efforts in electronic structure theory and non-equilibrium statistical mechanical & multiscale modeling. The primary focus is on the development and especially application of methods that enable the

  4. Sandia researcher Stephanie Hansen receives DOE Early Career award |

    National Nuclear Security Administration (NNSA)

    National Nuclear Security Administration | (NNSA) researcher Stephanie Hansen receives DOE Early Career award Monday, June 9, 2014 - 3:47pm NNSA Blog Sandia National Laboratories researcher Stephanie Hansen has received a $2.5 million, five-year Early Career Research Program award from the DOE's Office of Science for her fundamental science proposal to improve existing atomic-scale models for high-energy-density matter. Hansen's winning submission, "Non-Equilibrium Atomic Physics in

  5. Modeling for Anaerobic Fixed-Bed Biofilm Reactors

    SciTech Connect

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

    1989-06-01

    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.

  6. K+ block is the mechanism of functional asymmetry in bacterial Nav channels

    DOE PAGES [OSTI]

    Ngo, Van; Wang, Yibo; Haas, Stephan; Noskov, Sergei Y.; Farley, Robert A.; Weinstein, Harel

    2016-01-04

    Crystal structures of several bacterial Nav channels have been recently published and molecular dynamics simulations of ion permeation through these channels are consistent with many electrophysiological properties of eukaryotic channels. Bacterial Nav channels have been characterized as functionally asymmetric, and the mechanism of this asymmetry has not been clearly understood. To address this question, we combined non-equilibrium simulation data with two-dimensional equilibrium unperturbed landscapes generated by umbrella sampling and Weighted Histogram Analysis Methods for multiple ions traversing the selectivity filter of bacterial NavAb channel. This approach provided new insight into the mechanism of selective ion permeation in bacterial Nav channels.more » The non-equilibrium simulations indicate that two or three extracellular K+ ions can block the entrance to the selectivity filter of NavAb in the presence of applied forces in the inward direction, but not in the outward direction. The block state occurs in an unstable local minimum of the equilibrium unperturbed free-energy landscape of two K+ ions that can be ‘locked’ in place bymodest applied forces. In contrast to K+, three Na+ ions move favorably through the selectivity filter together as a unit in a loose “knock-on” mechanism of permeation in both inward and outward directions, and there is no similar local minimum in the two-dimensional free-energy landscape of two Na+ ions for a block state. The useful work predicted by the non-equilibrium simulations that is required to break the K+ block is equivalent to large applied potentials experimentally measured for two bacterial Nav channels to induce inward currents of K+ ions. Here, these results illustrate how inclusion of non-equilibrium factors in the simulations can provide detailed information about mechanisms of ion selectivity that is missing from mechanisms derived from either crystal structures or equilibrium unperturbed free

  7. Measurement of electron-ion relaxation in warm dense copper

    DOE PAGES [OSTI]

    Cho, B. I.; Ogitsu, T.; Engelhorn, K.; Correa, A. A.; Ping, Y.; Lee, J. W.; Bae, L. J.; Prendergast, D.; Falcone, R. W.; Heimann, P. A.

    2016-01-06

    Experimental investigation of electron-ion coupling and electron heat capacity of copper in warm and dense states are presented. From time-resolved x-ray absorption spectroscopy, the temporal evolution of electron temperature is obtained for non-equilibrium warm dense copper heated by an intense femtosecond laser pulse. Electron heat capacity and electron-ion coupling are inferred from the initial electron temperature and its decrease over 10 ps. As a result, data are compared with various theoretical models.

  8. The effect of a magnetic field on the spin-selective transport in double-stranded DNA

    SciTech Connect

    Simchi, Hamidreza; Esmaeilzadeh, Mahdi Mazidabadi, Hossein

    2014-05-28

    Spin-polarization in double-stranded DNA is studied in the presence of a magnetic field applied along its helix axis using the non-equilibrium Green's function method. The spin-polarization could be tuned by changing the magnetic field. In some special cases, the double-stranded DNA behaved as a perfect spin-filter. Furthermore, the dependency of the spin-polarization on the spin-orbit strength and dephasing strength is studied.

  9. Lattice distortions and oxygen vacancies produced in Au+ irradiated nano-crystalline cubic zirconia

    SciTech Connect

    Edmondson, Philip D; Weber, William J; Namavar, Fereydoon; Zhang, Yanwen

    2011-01-01

    The structural impact of oxygen vacancies in nanocrystalline cubic zirconia is investigated. A non-equilibrium number of oxygen vacancies in introduced to the lattice by ion irradiation. The lattice is observed to be initially compressed, undergoes a relaxation at 0.7 displacements per atom (dpa), and experiences a contraction before reaching a temperature dependent steady state value at above 7 dpa. The level of lattice distortion is related to the charge state of the accumulating oxygen vacancies.

  10. Phonon coherence in isotopic silicon superlattices

    SciTech Connect

    Frieling, R.; Radek, M.; Eon, S.; Bracht, H.; Wolf, D. E.

    2014-09-29

    Recent experimental and theoretical investigations have confirmed that a reduction in thermal conductivity of silicon is achieved by isotopic silicon superlattices. In the present study, non-equilibrium molecular dynamics simulations are performed to identify the isotope doping and isotope layer ordering with minimum thermal conductivity. Furthermore, the impact of isotopic intermixing at the superlattice interfaces on phonon transport is investigated. Our results reveal that the coherence of phonons in isotopic Si superlattices is prevented if interfacial mixing of isotopes is considered.

  11. Microsoft Word - strickland_abstract

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    15th, 4:00 PM Dynamics of an anisotropic quark gluon plasma Dr. Michael Strickland Gettysburg College Abstract: In this talk I will review our theoretical understanding of the dynamics of a non- equilibrium quark gluon plasma. I will begin by discussing the emergence of strong local momentum-space anisotropies in the plasma due to the rapid longitudinal expansion of the plasma at early times. While strongly-coupled plasmas might remain approximately isotropic in the center of the collision

  12. ASC eNews (June 2014)

    National Nuclear Security Administration (NNSA)

    June 2014 Page 1 of 34 Contents: (To go directly to an article, click on its title below.) The Meisner Minute Trinity-NNSA ASC's First Advanced Technology System A New Take on Simulation Uncertainty "Cramming" Sequoia Full of Jobs for Uncertainty Quantification ParticlePack: Packing a Peck of Pickled Peppers Scaling Studies for Simulation of Non-Equilibrium Flow using SPARTA on the Sequoia Platform Pinch Weld Process Modeling to Improve GTS Reservoir Stem Weld Quality Predictive

  13. Vehicle Technologies Office Merit Review 2015: High Strength, Dissimilar

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Alloy Aluminum Tailor-Welded Blanks | Department of Energy High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks Vehicle Technologies Office Merit Review 2015: High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks Presentation given by Pacific Northwest National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high strength, dissimilar alloy aluminum tailor-welded blanks.

  14. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript Journal Name: Subject: Identifier Numbers: ... techniques. less February 2016 , American Chemical Society Tailoring of a metastable material: ...

  15. Better Buildings Residential Network: Lessions Learned: Peer...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    2014 Outreach: Providing tailored marketing materials and flexible messaging are ... Topics include: Data and Evaluation Financing and Revenue Marketing and ...

  16. Possible dynamical explanations for Paltridge's principle of maximum entropy production

    SciTech Connect

    Virgo, Nathaniel Ikegami, Takashi

    2014-12-05

    Throughout the history of non-equilibrium thermodynamics a number of theories have been proposed in which complex, far from equilibrium flow systems are hypothesised to reach a steady state that maximises some quantity. Perhaps the most celebrated is Paltridge's principle of maximum entropy production for the horizontal heat flux in Earth's atmosphere, for which there is some empirical support. There have been a number of attempts to derive such a principle from maximum entropy considerations. However, we currently lack a more mechanistic explanation of how any particular system might self-organise into a state that maximises some quantity. This is in contrast to equilibrium thermodynamics, in which models such as the Ising model have been a great help in understanding the relationship between the predictions of MaxEnt and the dynamics of physical systems. In this paper we show that, unlike in the equilibrium case, Paltridge-type maximisation in non-equilibrium systems cannot be achieved by a simple dynamical feedback mechanism. Nevertheless, we propose several possible mechanisms by which maximisation could occur. Showing that these occur in any real system is a task for future work. The possibilities presented here may not be the only ones. We hope that by presenting them we can provoke further discussion about the possible dynamical mechanisms behind extremum principles for non-equilibrium systems, and their relationship to predictions obtained through MaxEnt.

  17. Ultrafast pulse amplification in mode-locked vertical external-cavity surface-emitting lasers

    SciTech Connect

    Böttge, C. N. Hader, J.; Kilen, I.; Moloney, J. V.; Koch, S. W.

    2014-12-29

    A fully microscopic many-body Maxwell–semiconductor Bloch model is used to investigate the influence of the non-equilibrium carrier dynamics on the short-pulse amplification in mode-locked semiconductor microlaser systems. The numerical solution of the coupled equations allows for a self-consistent investigation of the light–matter coupling dynamics, the carrier kinetics in the saturable absorber and the multiple-quantum-well gain medium, as well as the modification of the light field through the pulse-induced optical polarization. The influence of the pulse-induced non-equilibrium modifications of the carrier distributions in the gain medium and the saturable absorber on the single-pulse amplification in the laser cavity is identified. It is shown that for the same structure, quantum wells, and gain bandwidth the non-equilibrium carrier dynamics lead to two preferred operation regimes: one with pulses in the (sub-)100 fs-regime and one with multi-picosecond pulses. The recovery time of the saturable absorber determines in which regime the device operates.

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

    SciTech Connect

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

    2009-08-01

    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.

  19. Vehicle Technologies Office Merit Review 2016: High Strength, Dissimilar

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Alloy Aluminum Tailor-Welded Blanks | Department of Energy High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks Vehicle Technologies Office Merit Review 2016: High Strength, Dissimilar Alloy Aluminum Tailor-Welded Blanks Presentation given by Pacific Northwest National Laboratory (PNNL) at the 2016 DOE Vehicle Technologies Office and Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting about Lightweighting lm099_hovanski_2016_o_web.pdf (3.63 MB) More

  20. On thermalization of electron-positron-photon plasma

    SciTech Connect

    Siutsou, I. A.; Aksenov, A. G.

    2015-12-17

    Recently a progress has been made in understanding thermalization mechanism of relativistic plasma starting from a non-equilibrium state. Relativistic Boltzmann equations were solved numerically for homogeneous isotropic plasma with collision integrals for two- and three-particle interactions calculated from the first principles by means of QED matrix elements. All particles were assumed to fulfill Boltzmann statistics. In this work we follow plasma thermalization by accounting for Bose enhancement and Pauli blocking in particle interactions. Our results show that particle in equilibrium reach Bose-Einstein distribution for photons, and Fermi-Dirac one for electrons, respectively.

  1. Periodically sheared 2D Yukawa systems

    SciTech Connect

    Kovács, Anikó Zsuzsa; Hartmann, Peter; Donkó, Zoltán

    2015-10-15

    We present non-equilibrium molecular dynamics simulation studies on the dynamic (complex) shear viscosity of a 2D Yukawa system. We have identified a non-monotonic frequency dependence of the viscosity at high frequencies and shear rates, an energy absorption maximum (local resonance) at the Einstein frequency of the system at medium shear rates, an enhanced collective wave activity, when the excitation is near the plateau frequency of the longitudinal wave dispersion, and the emergence of significant configurational anisotropy at small frequencies and high shear rates.

  2. Scanning tunneling spectroscopy of a magnetic atom on graphene in the Kondo

    Office of Scientific and Technical Information (OSTI)

    regime (Journal Article) | DOE PAGES Scanning tunneling spectroscopy of a magnetic atom on graphene in the Kondo regime Title: Scanning tunneling spectroscopy of a magnetic atom on graphene in the Kondo regime In this study, the Kondo effect in the system consisting of a magnetic adatom on the graphene is studied. By using the non-equilibrium Green function method with the slave-boson mean field approximation, the local density of state (LDOS) and the conductance are calculated. For a doped

  3. Spintronic transport of a non-magnetic molecule between magnetic electrodes

    SciTech Connect

    Kondo, Hisashi; Ohno, Takahisa; Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505

    2013-12-02

    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.

  4. Detonation Reaction Zones in Condensed Explosives

    SciTech Connect

    Tarver, C M

    2005-07-14

    Experimental measurements using nanosecond time resolved embedded gauges and laser interferometric techniques, combined with Non-Equilibrium Zeldovich--von Neumann--Doring (NEZND) theory and Ignition and Growth reactive flow hydrodynamic modeling, have revealed the average pressure/particle velocity states attained in reaction zones of self-sustaining detonation waves in several solid and liquid explosives. The time durations of these reaction zone processes is discussed for explosives based on pentaerythritol tetranitrate (PETN), nitromethane, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), triaminitrinitrobenzene(TATB) and trinitrotoluene (TNT).

  5. Electric response of a metal-molecule-metal junction to laser pulse by solving hierarchical equations of motion

    SciTech Connect

    Cao, Hui Zhang, Mingdao; Tao, Tao; Song, Mingxia; Zhang, Chaozhi

    2015-02-28

    We have combined the quantum dissipative theory and the time dependent density functional theory to perform the first principle calculation of laser induced quantum dynamical electron transport through a molecule weak bridged to two electrodes. The formalism of hierarchical equations of motion based on non-equilibrium Green’s function theory has been taken in this work. Numerical simulations of optical absorption spectra of benzene, laser induced transient current without and with bias, charge pumping effect, as well as the spectrum analysis from the current in Au-benzene-Au molecular junction are presented and discussed.

  6. Nanowire terahertz quantum cascade lasers

    SciTech Connect

    Grange, Thomas

    2014-10-06

    Quantum cascade lasers made of nanowire axial heterostructures are proposed. The dissipative quantum dynamics of their carriers is theoretically investigated using non-equilibrium Green functions. Their transport and gain properties are calculated for varying nanowire thickness, from the classical-wire regime to the quantum-wire regime. Our calculation shows that the lateral quantum confinement provided by the nanowires allows an increase of the maximum operation temperature and a strong reduction of the current density threshold compared to conventional terahertz quantum cascade lasers.

  7. Diagnostic of laser-accelerated ion beams for the ELIMED project

    SciTech Connect

    Torrisi, L.; INFN-Laboratori Nazionali del Sud, V. S. Sofia 64, 95123 Catania ; Cutroneo, M.; Cavallaro, S.; Andò, L.; Calcagno, L.; Musumeci, P.

    2013-07-26

    The laser-generated plasma, in non equilibrium conditions, has peculiar properties depending strongly on the laser parameters, on the target composition and on the target geometry. Different fast diagnostic techniques can be employed for the plasma characterization in terms of particles and photons emission, plasma temperature and density, ion energy distribution, angular emission, yield and electric field acceleration. Particular attention is devoted to the proton emission from hydrogenated targets and to the proton diagnostics by using time of flight techniques and Thomson parabola spectrometry. The diagnostic techniques will be presented and discussed on the base of the development of the ELIMED project.

  8. Fokker-Planck equation in mirror research

    SciTech Connect

    Post, R.F.

    1983-08-11

    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.

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

    SciTech Connect

    Sofronov, A. N.; Firsov, D. A.; Vorobjev, L. E.; Shalygin, V. A.; Panevin, V. Yu.; Vinnichenko, M. Ya.; Tonkikh, A. A.; Danilov, S. N.

    2013-12-04

    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.

  10. Method and apparatus for chemically altering fluids in continuous flow

    DOEpatents

    Heath, William O.; Virden, Jr., Judson W.; Richardson, R. L.; Bergsman, Theresa M.

    1993-01-01

    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.

  11. Method and apparatus for chemically altering fluids in continuous flow

    DOEpatents

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

    1993-10-19

    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.

  12. Basic knowledge on radiative and transport properties to begin in thermal plasmas modelling

    SciTech Connect

    Cressault, Y.

    2015-05-15

    This paper has for objectives to present the radiative and the transport properties for people beginning in thermal plasmas. The first section will briefly recall the equations defined in numerical models applied to thermal plasmas; the second section will particularly deal with the estimation of radiative losses; the third part will quickly present the thermodynamics properties; and the last part will concern the transport coefficients (thermal conductivity, viscosity and electrical conductivity of the gas or mixtures of gases). We shall conclude the paper with a discussion about the validity of these results the lack of data for some specific applications, and some perspectives concerning these properties for non-equilibrium thermal plasmas.

  13. Influence of interface roughness in quantum cascade lasers

    SciTech Connect

    Krivas, K. A.; Winge, D. O.; Franckié, M.; Wacker, A.

    2015-09-21

    We use a numerical model based on non-equilibrium Green's functions to investigate the influence of interface roughness (IFR) scattering in terahertz quantum cascade lasers. We confirm that IFR is an important phenomenon that affects both current and gain. The simulations indicate that IFR causes a leakage current that transfers electrons from the upper to the lower laser state. In certain cases, this current can greatly reduce gain. In addition, individual interfaces and their impact on the renormalized single particle energies are studied and shown to give both blue- and red-shifts of the gain spectrum.

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

    SciTech Connect

    Lange, H.; Labedz, O.; Huczko, A.; Bystrzejewski, M.

    2011-11-29

    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.

  15. Modeling direct interband tunneling. II. Lower-dimensional structures

    SciTech Connect

    Pan, Andrew; Chui, Chi On

    2014-08-07

    We investigate the applicability of the two-band Hamiltonian and the widely used Kane analytical formula to interband tunneling along unconfined directions in nanostructures. Through comparisons with kp and tight-binding calculations and quantum transport simulations, we find that the primary correction is the change in effective band gap. For both constant fields and realistic tunnel field-effect transistors, dimensionally consistent band gap scaling of the Kane formula allows analytical and numerical device simulations to approximate non-equilibrium Green's function current characteristics without arbitrary fitting. This allows efficient first-order calibration of semiclassical models for interband tunneling in nanodevices.

  16. Light-driven superconductivity in K3C60 at elevated temperature | Stanford

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Synchrotron Radiation Lightsource Light-driven superconductivity in K3C60 at elevated temperature Wednesday, October 12, 2016 - 1:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Alice Cantaluppi, Max Planck Institute Program Description Non-equilibrium superconducting-like optical signatures have been observed in a sample of K3C60 upon photo-excitation at temperatures up to 100K. In this experiment a coherent distortion of the lattice is driven by means of intense ultrashort laser

  17. Temperature dependence of the photo-induced inverse spin Hall effect in Au/InP hybrid structures

    SciTech Connect

    Khamari, Shailesh K. Porwal, S.; Dixit, V. K.; Sharma, T. K.

    2014-01-27

    Photo-induced Inverse Spin Hall Effect (ISHE) measurements on Au/InP hybrid structures are performed over a temperature range of 45 to 300 K. Dependence of the spin current density on the degree of circular polarization and also on the angle of incidence of laser beam confirms the ISHE origin of measured signal. The magnitude of ISHE increases with sample cooling. A numerical model based on the spin relaxation of non-equilibrium spin-polarized electrons is proposed for predicting the temperature dependence of ISHE. Our results indicate that the proposed device can be used as a spin photodetector over a wide temperature range.

  18. The effect of electron-electron interaction induced dephasing on electronic transport in graphene nanoribbons

    SciTech Connect

    Kahnoj, Sina Soleimani; Touski, Shoeib Babaee; Pourfath, Mahdi E-mail: pourfath@iue.tuwien.ac.at

    2014-09-08

    The effect of dephasing induced by electron-electron interaction on electronic transport in graphene nanoribbons is theoretically investigated. In the presence of disorder in graphene nanoribbons, wavefunction of electrons can set up standing waves along the channel and the conductance exponentially decreases with the ribbon's length. Employing the non-equilibrium Green's function formalism along with an accurate model for describing the dephasing induced by electron-electron interaction, we show that this kind of interaction prevents localization and transport of electrons remains in the diffusive regime where the conductance is inversely proportional to the ribbon's length.

  19. Getting Results from behavior-based Conservation Projects

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ... Use known and trusted sources to deliver messages Gave direction and outlined content Tailored emails and personal conversations 9 Energy Exchange: Federal Sustainability for the ...

  20. Energy Efficiency Title

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    posed similar questions to all stakeholders, with additional tailored questions for each type of respondent. Peer Utility Interviews Our interviews (n4) with peer utilities...

  1. Metal segregation in hierarchically structured cathode materials...

    Office of Scientific and Technical Information (OSTI)

    due to the tailored surface chemistry, compared to conventional NMC-442 materials. ... Nanomaterials; batteries; materials chemistry; surface chemistry Word Cloud More Like ...

  2. A New Route to Nano Self-Assembly

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    critical to tailoring the macroscopic properties during nanoparticle assembly. Although DNA has been used to induce self-assembly of nanoparticles with a high degree of...

  3. David L. Rogow | Center for Gas SeparationsRelevant to Clean...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    EFRC research: The focus of my research is on the rational design and synthesis of metal-organic framework (MOF) materials that are tailored with specific functionality for ...

  4. Search for: All records | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    PBL heights were derived from these merged potential temperature profiles usingmore a modified Heffter (1980) technique that was tailored to the SGP site (Della Monache et al., ...

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    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Towards High-Flux Isolated Attosecond Pulses with a 200 TW CPA 12092015 Understand morphology of organic semiconductors, for better tailoring it 12022015 Science Driver...

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    OpenEI (Open Energy Information) [EERE & EIA]

    entitled Navigating Transport NAMAs, which is tailored to each target group, outlines the instruments and technologies available as well as the context for climate negotiations...

  7. Providing Diurnal Sky Cover Data at ARM Sites (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    for the ASIVA instrument that could be implemented in real time and tailored for cloud modelers. This final report describes Solmirus' research and findings enabled by this grant. ...

  8. Peptoid Nanosheets Offer a Diversity of Functionalities

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    be tailored with great precision. And since peptoids are less vulnerable to chemical or metabolic breakdown than proteins, they are a highly promising platform for...

  9. Michigan Wind Maufacturer Teams with College on Training | Department...

    Energy.gov [DOE] (indexed site)

    ... all across Michigan. "We go out and find what types of employees companies need and tailor training programs around those skills," she says. "We have solar photovoltaic ...

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    require the production of clean hydrogen to fuel innovative combustion turbines and fuel cells. This research will focus on development and assessment of membranes tailored...

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    Office of Environmental Management (EM)

    memorandum memorializes the process the Department has used in implementing a tailored approach for streamlining the Energy Systems Acquisition Advisory Board (ESAAB) process...

  12. Flipping Photoelectron Spins in Topological Insulators

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    Spintronics The ability to shine polarized light on a topological insulator (TI) and excite spin-polarization-tailored electrons has great potential for the field of spintronics - ...

  13. Laser Seeding Yields High-Power Coherent Terahertz Radiation

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    Laser Seeding Yields High-Power Coherent Terahertz Radiation Print Researchers at Berkeley ... by femtoslicing (see "Tailored Terahertz Pulses from a Laser-Modulated Electron Beam"). ...

  14. Bigger's Not Always Better

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    Latest Issue:April 2016 past issues All Issues submit Bigger's Not Always Better Accuracy trumps explosive power when the Department of Defense seeks nuclear weapons tailored to ...

  15. Windspire Energy formerly Mariah Power | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Mariah Power) Place: Reno, Nevada Zip: 89521 Product: Mariah Power develops technology specifically tailored to be low-cost and affordable for urban, suburban, and rural...

  16. Microsoft PowerPoint - Gao_2014_CINT-CNMS User Project Highlight...

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    Graphene oxide (GO) contains several chemical functional groups that are attached to the graphene basal plane and can be manipulated to tailor GO for specific applications. In this...

  17. Microsoft Word - Delft_04STC-Abstract.doc

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    flutter may become a more important design consideration. In addition, innovative blade designs involving the use of aeroelastic tailoring, wherein the blade twists as it...

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    From designing tailored superconductors to transform the nation's energy grid to developing better materials for wind turbines and finding potential replacements for silicon for ...

  19. Merit Review Guide | Department of Energy

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    merit reviews of financial assistance applications. While programproject officials are encouraged to tailor this guidance to their specific programs, merit reviews should be ...

  20. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    The domain structure evolution was attributed to the action of pyroelectric field appeared ... experimental results and can be used for creation of tailored domain structures thus ...

  1. CCTUpdate2013_7-18-13.indd

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    ... C-2 Exhibits ii ES-1 Executive Summary ... Tailoring Rule under the express terms and intent of the ... 2 stream that can then be compressed for pipeline transport. ...

  2. Todd Munson | Argonne National Laboratory

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    of the linear support vector machine problem enabled MCS staff to write tailored linear algebra in interior-point and semismooth algorithms so that they can solve...

  3. Local stress engineering of magnetic anisotropy in soft magnetic...

    Office of Scientific and Technical Information (OSTI)

    to tailor the ferromagnetic thin film structure used in magnetoelectronic applications. ... Leibniz Institute for Solid State and Materials Research IFW Dresden, Postfach 270116, ...

  4. EBITSCHenergietechnik | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    EBITSCHenergietechnik Jump to: navigation, search Name: EBITSCHenergietechnik Place: Germany Sector: Renewable Energy Product: Germany-based firm that offers tailor-made economic...

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    Simulation-Based Engineering Water Management R&D View Project ... Benefits Of Tailoring Hot Isostatic Pressure... for Direct Power Extraction Electrode Applications ...

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    tailored materials; and polymers. AWARDS: Nominations for the Shirley (Science), Halbach (Instrumentation), and Renner (Service) Awards will accepted until Monday, August 31,...

  7. A Revolutionary Hybrid Thermodynamic Cycle for Bianary Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    PDF icon hybridthermcyclepeer2013.pdf More Documents & Publications Working Fluids and Their Effect on Geothermal Turbines Tailored Working Fluids for Enhanced Binary Geothermal ...

  8. Development of Acicular Mullite Materials for Diesel Particulate...

    Energy.gov [DOE] (indexed site)

    Tailored Acicular Mullite Substrates for Multifunctional Diesel Particulate Filters Future Trends for DPFSCR On-Filter (SCRF) fundamental Modeling and Experimental Studies of ...

  9. Quality Management System Guidelines - Building America Top Innovation...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Quality management tools tailored for the high performance homebuilding industry provide ... View other Top Innovations in the Effective Guidance and Tools category. Top Innovation - ...

  10. EM Corporate Performance Measures - Site Office Level | Department...

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    The Office of Environmental Management assigns specific measures to each site that is tailored to the unique nature and scope of each area's contamination and cleanup work. EM ...

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    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    sense, tailor the process to the project scope *Eligible utilities: 1) are the local ... goals - Describe the initial project scope - Inform utility that you are providing ...

  12. Vietnam-Lowering Emissions in Asia's Forests (LEAF) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    assessing, improving, and implementing REDD+- related forest policies; improving forest management; and encouraging equitable sharing of REDD+ benefits. The program will tailor...

  13. Malaysia-Lowering Emissions in Asia's Forests (LEAF) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    assessing, improving, and implementing REDD+- related forest policies; improving forest management; and encouraging equitable sharing of REDD+ benefits. The program will tailor...

  14. Papua New Guinea-Lowering Emissions in Asia's Forests (LEAF)...

    OpenEI (Open Energy Information) [EERE & EIA]

    assessing, improving, and implementing REDD+- related forest policies; improving forest management; and encouraging equitable sharing of REDD+ benefits. The program will tailor...

  15. Laos-Lowering Emissions in Asia's Forests (LEAF) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    assessing, improving, and implementing REDD+- related forest policies; improving forest management; and encouraging equitable sharing of REDD+ benefits. The program will tailor...

  16. Thailand-Lowering Emissions in Asia's Forests (LEAF) | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    assessing, improving, and implementing REDD+- related forest policies; improving forest management; and encouraging equitable sharing of REDD+ benefits. The program will tailor...

  17. nastasi EFRC Single Slide revised with new name v2.ppt

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    contribute to defect and damage evolution in materials, and use this information to design nanostructured materials with tailored response at irradiation and mechanical...

  18. ALSNews Vol. 316

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Rope, and Another Step Toward Complex Nanomaterials That Assemble Themselves Tailoring fungi-based biofuels to meet the needs of combustion engines Subscribe to ALSNews Email: Go...

  19. Harnessing the Bacterial Power of Nanomagnets

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    tailored for different uses. A relatively unexplored resource for magnetic nanomaterial production is a type of subsurface microorganism capable of producing large...

  20. About Us | Argonne National Laboratory

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    to tailor nanoscale interactions by creating, visualizing, and assembling hybrid nanomaterial architectures for energy-related research and development programs. High-impact...

  1. Superlattices Patterned by Polymers

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    grafted onto their surfaces ("hairy nanoparticles," or polymer "brushes"), can be tailored to exhibit desired characteristics for applications ranging from nano- to biotechnology. ...

  2. Center for Nanophase Materials Sciences (CNMS) - CNMS User Research

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    and Humberto Terrones, Instituto Potosino de Investigacion Cientifica y Tecnologica, San Luis Potosi, Mexico Novel and robust networks, tailored from nanostructures as...

  3. XP-SiC: An Innovative Substrate for Future Applications with...

    Energy.gov [DOE] (indexed site)

    Key Parameters Affecting DPF Performance Degradation and Impact on Lifetime Fuel Economy A Standard Soot Generator for Diesel Particulate Filter Testing Tailored Acicular Mullite ...

  4. SAND2008-6687

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ... at 300 K: Xe and Kr insertiondeletion statistics and guest mole fractions in the ... materials whose pore size and chemical environment can be chemically tailored because of ...

  5. EC Publications

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Sensitivity Study of a Large Photovoltaic System (2327 downloads) Sandia's ... Sandia's work in Fuel cell membrane research examines several organic polymer platforms tailored ...

  6. Research | Argonne National Laboratory

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Division focus on research that addresses grand challenges in nanoscience and nanotechnology and advances the division's user mission. Further, we are exploring ways to tailor...

  7. A general maximum entropy framework for thermodynamic variational principles

    SciTech Connect

    Dewar, Roderick C.

    2014-12-05

    Minimum free energy principles are familiar in equilibrium thermodynamics, as expressions of the second law. They also appear in statistical mechanics as variational approximation schemes, such as the mean-field and steepest-descent approximations. These well-known minimum free energy principles are here unified and extended to any system analyzable by MaxEnt, including non-equilibrium systems. The MaxEnt Lagrangian associated with a generic MaxEnt distribution p defines a generalized potential Ψ for an arbitrary probability distribution p-hat, such that Ψ is a minimum at (p-hat) = p. Minimization of Ψ with respect to p-hat thus constitutes a generic variational principle, and is equivalent to minimizing the Kullback-Leibler divergence between p-hat and p. Illustrative examples of min–Ψ are given for equilibrium and non-equilibrium systems. An interpretation of changes in Ψ is given in terms of the second law, although min–Ψ itself is an intrinsic variational property of MaxEnt that is distinct from the second law.

  8. Local equilibrium and the second law of thermodynamics for irreversible systems with thermodynamic inertia

    SciTech Connect

    Glavatskiy, K. S.

    2015-10-28

    Validity of local equilibrium has been questioned for non-equilibrium systems which are characterized by delayed response. In particular, for systems with non-zero thermodynamic inertia, the assumption of local equilibrium leads to negative values of the entropy production, which is in contradiction with the second law of thermodynamics. In this paper, we address this question by suggesting a variational formulation of irreversible evolution of a system with non-zero thermodynamic inertia. We introduce the Lagrangian, which depends on the properties of the normal and the so-called “mirror-image” systems. We show that the standard evolution equations, in particular, the Maxwell-Cattaneo-Vernotte equation, can be derived from the variational procedure without going beyond the assumption of local equilibrium. We also argue that the second law of thermodynamics in non-equilibrium should be understood as a consequence of the variational procedure and the property of local equilibrium. For systems with instantaneous response this leads to the standard requirement of the local instantaneous entropy production being always positive. However, if a system is characterized by delayed response, the formulation of the second law of thermodynamics should be altered. In particular, the quantity, which is always positive, is not the instantaneous entropy production, but the entropy production averaged over a proper time interval.

  9. Persistent order due to transiently enhanced nesting in an electronically excited charge density wave

    DOE PAGES [OSTI]

    Rettig, L.; Cortés, R.; Chu, J. -H.; Fisher, I. R.; Schmitt, F.; Moore, R. G.; Shen, Z. -X.; Kirchmann, P. S.; Wolf, M.; Bovensiepen, U.

    2016-01-25

    Non-equilibrium conditions may lead to novel properties of materials with broken symmetry ground states not accessible in equilibrium as vividly demonstrated by non-linearly driven mid-infrared active phonon excitation. Potential energy surfaces of electronically excited states also allow to direct nuclear motion, but relaxation of the excess energy typically excites fluctuations leading to a reduced or even vanishing order parameter as characterized by an electronic energy gap. Here, using femtosecond time-and angle-resolved photoemission spectroscopy, we demonstrate a tendency towards transient stabilization of a charge density wave after near-infrared excitation, counteracting the suppression of order in the non-equilibrium state. Analysis of themore » dynamic electronic structure reveals a remaining energy gap in a highly excited transient state. In conclusion, our observation can be explained by a competition between fluctuations in the electronically excited state, which tend to reduce order, and transiently enhanced Fermi surface nesting stabilizing the order.« less

  10. Oxygen transport properties estimation by DSMC-CT simulations

    SciTech Connect

    Bruno, Domenico; Frezzotti, Aldo; Ghiroldi, Gian Pietro

    2014-12-09

    Coupling DSMC simulations with classical trajectories calculations is emerging as a powerful tool to improve predictive capabilities of computational rarefied gas dynamics. The considerable increase of computational effort outlined in the early application of the method (Koura,1997) can be compensated by running simulations on massively parallel computers. In particular, GPU acceleration has been found quite effective in reducing computing time (Ferrigni,2012; Norman et al.,2013) of DSMC-CT simulations. The aim of the present work is to study rarefied Oxygen flows by modeling binary collisions through an accurate potential energy surface, obtained by molecular beams scattering (Aquilanti, et al.,1999). The accuracy of the method is assessed by calculating molecular Oxygen shear viscosity and heat conductivity following three different DSMC-CT simulation methods. In the first one, transport properties are obtained from DSMC-CT simulations of spontaneous fluctuation of an equilibrium state (Bruno et al, Phys. Fluids, 23, 093104, 2011). In the second method, the collision trajectory calculation is incorporated in a Monte Carlo integration procedure to evaluate the Taxman’s expressions for the transport properties of polyatomic gases (Taxman,1959). In the third, non-equilibrium zero and one-dimensional rarefied gas dynamic simulations are adopted and the transport properties are computed from the non-equilibrium fluxes of momentum and energy. The three methods provide close values of the transport properties, their estimated statistical error not exceeding 3%. The experimental values are slightly underestimated, the percentage deviation being, again, few percent.

  11. Tritium and neutron measurements of a solid state cell

    SciTech Connect

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

    1989-01-01

    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.

  12. Effect of surface roughness and size of beam on squeeze-film damping—Molecular dynamics simulation study

    SciTech Connect

    Kim, Hojin; Strachan, Alejandro

    2015-11-28

    We use large-scale molecular dynamics (MD) to characterize fluid damping between a substrate and an approaching beam. We focus on the near contact regime where squeeze film (where fluid gap is comparable to the mean free path of the gas molecules) and many-body effects in the fluid become dominant. The MD simulations provide explicit description of many-body and non-equilibrium processes in the fluid as well as the surface topography. We study how surface roughness and beam width increases the damping coefficient due to their effect on fluid mobility. We find that the explicit simulations are in good agreement with prior direct simulation Monte Carlo results except at near-contact conditions where many-body effects in the compressed fluid lead the increased damping and weaker dependence on beam width. We also show that velocity distributions near the beam edges and for short gaps deviate from the Boltzmann distribution indicating a degree of local non-equilibrium. These results will be useful to parameterize compact models used for microsystem device-level simulations and provide insight into mesoscale simulations of near-contact damping.

  13. Simulations of Turbulent Flows with Strong Shocks and Density Variations

    SciTech Connect

    Zhong, Xiaolin

    2012-12-13

    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.

  14. Influence of cooling rate on the development of multiple generations of {gamma}' precipitates in a commercial nickel base superalloy

    SciTech Connect

    Singh, A.R.P.; Nag, S.; Hwang, J.Y.; Viswanathan, G.B.; Tiley, J.; Srinivasan, R.; Fraser, H.L.; Banerjee, R.

    2011-09-15

    The compositional and microstructural evolution of different generations of {gamma}' precipitates during the continuous cooling of a commercial nickel base superalloy, Rene88DT, has been characterized by three dimensional atom probe tomography coupled with energy-filtered transmission electron microscopy studies. After solutionizing in the single {gamma} phase field, continuous cooling at a very high rate results in a monomodal size distribution of {gamma}' precipitates with a high nucleation density and non-equilibrium compositions. In contrast, a relatively slower cooling rate ({approx} 24 deg. C/min) results in a multi-modal size distribution of {gamma}' precipitates with the larger first generation primary precipitates exhibiting close to equilibrium composition, along with the smaller scale secondary {gamma}' precipitates, exhibiting non-equilibrium composition (excess of Co and Cr, depleted in Al and Ti). The composition of the {gamma} matrix near these precipitates also exhibits similar trends with the composition being closer to equilibrium near the primary precipitates as compared to the secondary precipitates. - Highlights: {yields} Effect of cooling rate on the precipitation of {gamma}' particles in commercial nickel base superalloy. {yields} Couples EFTEM and 3DAP studies to determine the composition and morphology of {gamma}' precipitates. {yields} Determination of near and far field compositional variations within the gamma matrix leading to subsequent precipitation.

  15. MEASURING NEBULAR TEMPERATURES: THE EFFECT OF NEW COLLISION STRENGTHS WITH EQUILIBRIUM AND {kappa}-DISTRIBUTED ELECTRON ENERGIES

    SciTech Connect

    Nicholls, David C.; Dopita, Michael A.; Sutherland, Ralph S.; Kewley, Lisa J.; Palay, Ethan

    2013-08-15

    In this paper we develop tools for observers to use when analyzing nebular spectra for temperatures and metallicities, with two goals: to present a new, simple method to calculate equilibrium electron temperatures for collisionally excited line flux ratios, using the latest atomic data; and to adapt current methods to include the effects of possible non-equilibrium ''{kappa}'' electron energy distributions. Adopting recent collision strength data for [O III], [S III], [O II], [S II], and [N II], we find that existing methods based on older atomic data seriously overestimate the electron temperatures, even when considering purely Maxwellian statistics. If {kappa} distributions exist in H II regions and planetary nebulae as they do in solar system plasmas, it is important to investigate the observational consequences. This paper continues our previous work on the {kappa} distribution. We present simple formulaic methods that allow observers to (1) measure equilibrium electron temperatures and atomic abundances using the latest atomic data, and (2) to apply simple corrections to existing equilibrium analysis techniques to allow for possible non-equilibrium effects. These tools should lead to better consistency in temperature and abundance measurements, and a clearer understanding of the physics of H II regions and planetary nebulae.

  16. Modeling Degradation in Solid Oxide Electrolysis Cells - Volume II

    SciTech Connect

    Manohar Motwani

    2011-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential,, within the electrolyte. The 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 near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, non-equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  17. Experimental evidence of new tetragonal polymorphs of silicon formed through ultrafast laser-induced confined microexplosion

    SciTech Connect

    Rapp, L.; Haberl, B.; Pickard, C. J.; Bradby, J. E.; Gamaly, E. G.; Williams, J. S.; Rode, A. V.

    2015-06-29

    Ordinary materials can transform into novel phases with new crystal structures at extraordinary high pressure and temperature applied under both equilibrium and non-equilibrium conditions 1-6. The recently developed method of ultra-short laser-induced confined microexplosions 7-9 extends the range of possible new phases by initiating a highly non-equilibrium plasma state deep inside a bulk material 7-12. Ultra-high quenching rates can help to overcome kinetic barriers to the formation of new metastable phases, while the surrounding pristine crystal confines the affected material and preserves it for further study 10-12. Here we demonstrate that ultra-rapid pressure release from a completely disordered plasma state in silicon produces several new metastable end phases quenched to ambient conditions. Their structure is determined from comparison to an ab initio random structure search which revealed six new energetically competitive potential phases, four tetragonal and two monoclinic ones. We show the presence of bt8 and st12, which have been predicted theoretically previously 13-15, but have not been observed in nature or in laboratory experiments. Additionally, the presence of the as yet unidentified silicon phase, Si-VIII and two of our other predicted tetragonal phases are highly likely within laser-affected zones. These findings pave the way for new materials with novel and exotic properties.

  18. Experimental evidence of new tetragonal polymorphs of silicon formed through ultrafast laser-induced confined microexplosion

    DOE PAGES [OSTI]

    Rapp, L.; Haberl, B.; Pickard, C. J.; Bradby, J. E.; Gamaly, E. G.; Williams, J. S.; Rode, A. V.

    2015-06-29

    Ordinary materials can transform into novel phases with new crystal structures at extraordinary high pressure and temperature applied under both equilibrium and non-equilibrium conditions 1-6. The recently developed method of ultra-short laser-induced confined microexplosions 7-9 extends the range of possible new phases by initiating a highly non-equilibrium plasma state deep inside a bulk material 7-12. Ultra-high quenching rates can help to overcome kinetic barriers to the formation of new metastable phases, while the surrounding pristine crystal confines the affected material and preserves it for further study 10-12. Here we demonstrate that ultra-rapid pressure release from a completely disordered plasma statemore » in silicon produces several new metastable end phases quenched to ambient conditions. Their structure is determined from comparison to an ab initio random structure search which revealed six new energetically competitive potential phases, four tetragonal and two monoclinic ones. We show the presence of bt8 and st12, which have been predicted theoretically previously 13-15, but have not been observed in nature or in laboratory experiments. Additionally, the presence of the as yet unidentified silicon phase, Si-VIII and two of our other predicted tetragonal phases are highly likely within laser-affected zones. These findings pave the way for new materials with novel and exotic properties.« less

  19. Groundwater transport and fate processes for radionuclides. Master`s thesis

    SciTech Connect

    Sullivan, K.L.

    1994-12-01

    This thesis focuses on groundwater transport and fate processes for selected radionuclides. It collates elementary concepts in hydrology, groundwater chemistry, radiological assessment and uncertainty analysis. Basic concepts of advective transport, dispersion and various sorption models are discussed. The advection-dispersion equation, formulated to include radioactive decay and linear equilibrium sorption, is presented with an explanation of terms and essential concepts. An analytical solution to the advection-dispersion equation is presented, which includes sorption and decay and is used in modeling trials to develop a qualitative understanding of the physical processes represented by the model. A numerical contaminant transport code (SUTRA) is then used to compare the linear and Langmuir sorption models when both are fitted to the same sorption isotherm data. Results from study of the literature covering a comparison between the Freundlich equilibrium isotherm and the linear equilibrium isotherm are presented. Time moment analysis of non- equilibrium sorption models is introduced as a quantitative approach to evaluating numerical errors when a linear equilibrium model is used to represent non-equilibrium sorption processes.

  20. Plastic flow modeling in glassy polymers

    SciTech Connect

    Clements, Brad

    2010-12-13

    developed glassy polymer model. While polymers are well known for their non-equilibrium deviatoric behavior we have found the need for incorporating both equilibrium and non-equilibrium volumetric behavior into our theory. Experimental evidence supporting the notion of non-equilibrium volumetric behavior will be summarized. Our polymer yield model accurately captures the stress plateau, softening and hardening and its yield stress predictions agree well with measured values for several glassy polymers including PMMA, PC, and an epoxy resin. We then apply our theory to plate impact experiments in an attempt to address the questions associated with high rate polymer yield in uniaxial strain configurations.

  1. Accommodating subject and instrument variations in spectroscopic determinations

    DOEpatents

    Haas, Michael J.; Rowe, Robert K.; Thomas, Edward V.

    2006-08-29

    A method and apparatus for measuring a biological attribute, such as the concentration of an analyte, particularly a blood analyte in tissue such as glucose. The method utilizes spectrographic techniques in conjunction with an improved instrument-tailored or subject-tailored calibration model. In a calibration phase, calibration model data is modified to reduce or eliminate instrument-specific attributes, resulting in a calibration data set modeling intra-instrument or intra-subject variation. In a prediction phase, the prediction process is tailored for each target instrument separately using a minimal number of spectral measurements from each instrument or subject.

  2. Private sector village enterprise a new approach to sustainable financing

    SciTech Connect

    Gay, C.F.

    1997-12-01

    This paper presents an enterprise plan for introducing solar power in a rural market, while providing economic development, and hence the ability of the user to pay for the power source. This plan is based on a product called GEEP - a solar sewing machine conversion kit. This kit can be retrofit onto pedal sewing machines and marketed to village tailors in India, as part of a marketing program which includes increased demand for tailored products which will allow the tailors to be able to finance the conversion kits.

  3. Supersonic Dislocation Bursts in Silicon

    DOE PAGES [OSTI]

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; Meyers, M. A.

    2016-06-06

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolutionmore » we successfully predict a dislocation density of 1.5 x 10(12) cm(-2) within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.« less

  4. Determination of deuterium–tritium critical burn-up parameter by four temperature theory

    SciTech Connect

    Nazirzadeh, M.; Ghasemizad, A.; Khanbabei, B.

    2015-12-15

    Conditions for thermonuclear burn-up of an equimolar mixture of deuterium-tritium in non-equilibrium plasma have been investigated by four temperature theory. The photon distribution shape significantly affects the nature of thermonuclear burn. In three temperature model, the photon distribution is Planckian but in four temperature theory the photon distribution has a pure Planck form below a certain cut-off energy and then for photon energy above this cut-off energy makes a transition to Bose-Einstein distribution with a finite chemical potential. The objective was to develop four temperature theory in a plasma to calculate the critical burn up parameter which depends upon initial density, the plasma components initial temperatures, and hot spot size. All the obtained results from four temperature theory model are compared with 3 temperature model. It is shown that the values of critical burn-up parameter calculated by four temperature theory are smaller than those of three temperature model.

  5. Quantum diffusion with drift and the Einstein relation. I

    SciTech Connect

    De Roeck, Wojciech; Fröhlich, Jürg; Schnelli, Kevin

    2014-07-15

    We study the dynamics of a quantum particle hopping on a simple cubic lattice and driven by a constant external force. It is coupled to an array of identical, independent thermal reservoirs consisting of free, massless Bose fields, one at each site of the lattice. When the particle visits a site x of the lattice it can emit or absorb field quanta of the reservoir at x. Under the assumption that the coupling between the particle and the reservoirs and the driving force are sufficiently small, we establish the following results: The ergodic average over time of the state of the particle approaches a non-equilibrium steady state describing a non-zero mean drift of the particle. Its motion around the mean drift is diffusive, and the diffusion constant and the drift velocity are related to one another by the Einstein relation.

  6. Thermal transport in UO2 with defects and fission products by molecular dynamics simulations

    SciTech Connect

    Liu, Xiang-Yang; Cooper, Michael William Donald; Mcclellan, Kenneth James; Lashley, Jason Charles; Byler, Darrin David; Stanek, Christopher Richard; Andersson, Anders David Ragnar

    2015-10-14

    The importance of the thermal transport in nuclear fuel has motivated a wide range of experimental and modelling studies. In this report, the reduction of thermal transport in UO2 due to defects and fission products has been investigated using non-equilibrium MD simulations, with two sets of empirical potentials for studying the degregation of UO2 thermal conductivity including a Buckingham type interatomic potential and a recently developed EAM type interatomic potential. Additional parameters for U5+ and Zr4+ in UO2 have been developed for the EAM potential. The thermal conductivity results from MD simulations are then corrected for the spin-phonon scattering through Callaway model formulations. To validate the modelling results, comparison was made with experimental measurements on single crystal hyper-stoichiometric UO2+x samples.

  7. Lagrangian formulation of irreversible thermodynamics and the second law of thermodynamics

    SciTech Connect

    Glavatskiy, K. S.

    2015-05-28

    We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a Lagrangian, which depends on the properties of the normal and the so-called “mirror-image” system. The Lagrangian is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the Lagrangian. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such that there exists an “integral of evolution” which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium.

  8. Controllable growth of layered selenide and telluride heterostructures and superlattices using molecular beam epitaxy

    DOE PAGES [OSTI]

    Vishwanath, Suresh; Liu, Xinyu; Rouvimov, Sergei; Basile, Leonardo; Lu, Ning; Azcatl, Angelica; Magno, Katrina; Wallace, Robert M.; Kim, Moon; Idrobo, Juan -Carlos; et al

    2016-01-06

    Layered materials are an actively pursued area of research for realizing highly scaled technologies involving both traditional device structures as well as new physics. Lately, non-equilibrium growth of 2D materials using molecular beam epitaxy (MBE) is gathering traction in the scientific community and here we aim to highlight one of its strengths, growth of abrupt heterostructures, and superlattices (SLs). In this work we present several of the firsts: first growth of MoTe2 by MBE, MoSe2 on Bi2Se3 SLs, transition metal dichalcogenide (TMD) SLs, and lateral junction between a quintuple atomic layer of Bi2Te3 and a triple atomic layer of MoTe2.more » In conclusion, reflected high electron energy diffraction oscillations presented during the growth of TMD SLs strengthen our claim that ultrathin heterostructures with monolayer layer control is within reach.« less

  9. Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy

    SciTech Connect

    Shur, V. Ya. Zelenovskiy, P. S.

    2014-08-14

    The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

  10. Reversible monolayer-to-crystalline phase transition in amphiphilic silsesquioxane at the air-water interface

    SciTech Connect

    Banerjee, R.; Sanyal, M. K.; Bera, M. K.; Gibaud, A.; Lin, B.; Meron, M.

    2015-02-17

    We report on the counter intuitive reversible crystallisation of two-dimensional monolayer of Trisilanolisobutyl Polyhedral Oligomeric SilSesquioxane (TBPOSS) on water surface using synchrotron x-ray scattering measurements. Amphiphilic TBPOSS form rugged monolayers and Grazing Incidence X-ray Scattering (GIXS) measurements reveal that the in-plane inter-particle correlation peaks, characteristic of two-dimensional system, observed before transition is replaced by intense localized spots after transition. The measured x-ray scattering data of the non-equilibrium crystalline phase on the air-water interface could be explained with a model that assumes periodic stacking of the TBPOSS dimers. These crystalline stacking relaxes upon decompression and the TBPOSS layer retains its initial monolayer state. The existence of these crystals in compressed phase is confirmed by atomic force microscopy measurements by lifting the materials on a solid substrate.

  11. Band filling effects on temperature performance of intermediate band quantum wire solar cells

    SciTech Connect

    Kunets, Vas. P. Furrow, C. S.; Ware, M. E.; Souza, L. D. de; Benamara, M.; Salamo, G. J.; Mortazavi, M.

    2014-08-28

    Detailed studies of solar cell efficiency as a function of temperature were performed for quantum wire intermediate band solar cells grown on the (311)A plane. A remotely doped one-dimensional intermediate band made of self-assembled In{sub 0.4}Ga{sub 0.6}As quantum wires was compared to an undoped intermediate band and a reference p-i-n GaAs sample. These studies indicate that the efficiencies of these solar cells depend on the population of the one-dimensional band by equilibrium free carriers. A change in this population by free electrons under various temperatures affects absorption and carrier transport of non-equilibrium carriers generated by incident light. This results in different efficiencies for both the doped and undoped intermediate band solar cells in comparison with the reference GaAs p-i-n solar cell device.

  12. UNIVERSALITY OF PHASE TRANSITION DYNAMICS: TOPOLOGICAL DEFECTS FROM SYMMETRY BREAKING

    SciTech Connect

    Zurek, Wojciech H.; Del Campo, Adolfo

    2014-02-13

    In the course of a non-equilibrium continuous phase transition, the dynamics ceases to be adiabatic in the vicinity of the critical point as a result of the critical slowing down (the divergence of the relaxation time in the neighborhood of the critical point). This enforces a local choice of the broken symmetry and can lead to the formation of topological defects. The Kibble-Zurek mechanism (KZM) was developed to describe the associated nonequilibrium dynamics and to estimate the density of defects as a function of the quench rate through the transition. During recent years, several new experiments investigating formation of defects in phase transitions induced by a quench both in classical and quantum mechanical systems were carried out. At the same time, some established results were called into question. We review and analyze the Kibble-Zurek mechanism focusing in particular on this surge of activity, and suggest possible directions for further progress.

  13. Quantum emitters dynamically coupled to a quantum field

    SciTech Connect

    Acevedo, O. L.; Quiroga, L.; Rodrguez, F. J.; Johnson, N. F.

    2013-12-04

    We study theoretically the dynamical response of a set of solid-state quantum emitters arbitrarily coupled to a single-mode microcavity system. Ramping the matter-field coupling strength in round trips, we quantify the hysteresis or irreversible quantum dynamics. The matter-field system is modeled as a finite-size Dicke model which has previously been used to describe equilibrium (including quantum phase transition) properties of systems such as quantum dots in a microcavity. Here we extend this model to address non-equilibrium situations. Analyzing the systems quantum fidelity, we find that the near-adiabatic regime exhibits the richest phenomena, with a strong asymmetry in the internal collective dynamics depending on which phase is chosen as the starting point. We also explore signatures of the crossing of the critical points on the radiation subsystem by monitoring its Wigner function; then, the subsystem can exhibit the emergence of non-classicality and complexity.

  14. Extended Lagrangian Born-Oppenheimer molecular dynamics simulations of the shock-induced chemistry of phenylacetylene

    SciTech Connect

    Cawkwell, M. J. Niklasson, Anders M. N.; Dattelbaum, Dana M.

    2015-02-14

    The initial chemical events that occur during the shock compression of liquid phenylacetylene have been investigated using self-consistent tight binding molecular dynamics simulations. The extended Lagrangian Born-Oppenheimer molecular dynamics formalism enabled us to compute microcanonical trajectories with precise conservation of the total energy. Our simulations revealed that the first density-increasing step under shock compression arises from the polymerization of phenylacetylene molecules at the acetylene moiety. The application of electronic structure-based molecular dynamics with long-term conservation of the total energy enabled us to identify electronic signatures of reactivity via monitoring changes in the HOMO-LUMO gap, and to capture directly adiabatic shock heating, transient non-equilibrium states, and changes in temperature arising from exothermic chemistry in classical molecular dynamics trajectories.

  15. Influence of electron–phonon interactions in single dopant nanowire transistors

    SciTech Connect

    Carrillo-Nuñez, H. Bescond, M. Cavassilas, N.; Dib, E.; Lannoo, M.

    2014-10-28

    Single dopant nanowire transistors can be viewed as the ultimate miniaturization of nano electronic devices. In this work, we theoretically investigate the influence of the electron-phonon coupling on their transport properties using a non-equilibrium Green's function approach in the self-consistent Born approximation. For an impurity located at the center of the wire we find that, at room temperature, acoustic phonons broaden the impurity level so that the bistability predicted in the ballistic regime is suppressed. Optical phonons are found to have a beneficial impact on carrier transport via a phonon-assisted tunneling effect. We discuss the position and temperature dependence of these effects, showing that such systems might be very promising for engineering of ultimate devices.

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

    SciTech Connect

    Frietsch, B.; Gahl, C.; Teichmann, M.; Weinelt, M.; Carley, R.; Döbrich, K.; Schwarzkopf, O.; Wernet, Ph.

    2013-07-15

    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.

  17. Mass flows in a prominence spine as observed in EUV

    SciTech Connect

    Kucera, T. A.; Gilbert, H. R.

    2014-07-20

    We analyze a quiescent prominence observed by the Solar Dynamics Observatory's Atmospheric Imaging Assembly (AIA) with a focus on mass and energy flux in the spine, measured using Lyman continuum absorption. This is the first time this type of analysis has been applied with an emphasis on individual features and fluxes in a quiescent prominence. The prominence, observed on 2010 September 28, is detectable in most AIA wavebands in absorption and/or emission. Flows along the spine exhibit horizontal bands 5''-10'' wide and kinetic energy fluxes on the order of a few times 10{sup 5} erg s{sup 1}cm{sup 2}, consistent with quiet sun coronal heating estimates. For a discrete moving feature we estimate a mass of a few times 10{sup 11} g. We discuss the implications of our derived properties for a model of prominence dynamics, the thermal non-equilibrium model.

  18. Statistical physics ""Beyond equilibrium

    SciTech Connect

    Ecke, Robert E

    2009-01-01

    The scientific challenges of the 21st century will increasingly involve competing interactions, geometric frustration, spatial and temporal intrinsic inhomogeneity, nanoscale structures, and interactions spanning many scales. We will focus on a broad class of emerging problems that will require new tools in non-equilibrium statistical physics and that will find application in new material functionality, in predicting complex spatial dynamics, and in understanding novel states of matter. Our work will encompass materials under extreme conditions involving elastic/plastic deformation, competing interactions, intrinsic inhomogeneity, frustration in condensed matter systems, scaling phenomena in disordered materials from glasses to granular matter, quantum chemistry applied to nano-scale materials, soft-matter materials, and spatio-temporal properties of both ordinary and complex fluids.

  19. Building a Road from Light to Energy

    SciTech Connect

    Li, Anton; Bilby, David; Barito, Adam; Vyletel, Brenda

    2013-07-18

    Representing the Center for Solar and Thermal Energy Conversion (CSTEC), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of the Center for Solar and Thermal Energy Conversion (CSTEC) is to design and to synthesize new materials for high efficiency photovoltaic (PV) and thermoelectric (TE) devices, predicated on new fundamental insights into equilibrium and non-equilibrium processes, including quantum phenomena, that occur in materials over various spatial and temporal scales.

  20. Enhancement of Spin-transfer torque switching via resonant tunneling

    SciTech Connect

    Chatterji, Niladri; Tulapurkar, Ashwin A.; Muralidharan, Bhaskaran

    2014-12-08

    We propose the use of resonant tunneling as a route to enhance the spin-transfer torque switching characteristics of magnetic tunnel junctions. The proposed device structure is a resonant tunneling magnetic tunnel junction based on a MgO-semiconductor heterostructure sandwiched between a fixed magnet and a free magnet. Using the non-equilibrium Green's function formalism coupled self consistently with the Landau-Lifshitz-Gilbert-Slonczewski equation, we demonstrate enhanced tunnel magneto-resistance characteristics as well as lower switching voltages in comparison with traditional trilayer devices. Two device designs based on MgO based heterostructures are presented, where the physics of resonant tunneling leads to an enhanced spin transfer torque thereby reducing the critical switching voltage by up to 44%. It is envisioned that the proof-of-concept presented here may lead to practical device designs via rigorous materials and interface studies.

  1. Phonon mean free path of graphite along the c-axis

    SciTech Connect

    Wei, Zhiyong; Yang, Juekuan; Chen, Weiyu; Bi, Kedong; Chen, Yunfei, E-mail: yunfeichen@seu.edu.cn [Jiangsu Key Laboratory for Design and Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096 (China); Li, Deyu, E-mail: deyu.li@vanderbilt.edu [Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1592 (United States)

    2014-02-24

    Phonon transport in the c-axis direction of graphite thin films has been studied using non-equilibrium molecular dynamics (MD) simulation. The simulation results show that the c-axis thermal conductivities for films of thickness ranging from 20 to 500 atomic layers are significantly lower than the bulk value. Based on the MD data, a method is developed to construct the c-axis thermal conductivity as an accumulation function of phonon mean free path (MFP), from which we show that phonons with MFPs from 2 to 2000?nm contribute ?80% of the graphite c-axis thermal conductivity at room temperature, and phonons with MFPs larger than 100?nm contribute over 40% to the c-axis thermal conductivity. These findings indicate that the commonly believed value of just a few nanometers from the simple kinetic theory drastically underestimates the c-axis phonon MFP of graphite.

  2. Transport properties of zigzag graphene nanoribbon decorated with copper clusters

    SciTech Connect

    Berahman, M.; Sheikhi, M. H.

    2014-09-07

    Using non-equilibrium green function with density functional theory, the present study investigates the transport properties of decorated zigzag graphene nanoribbon with a copper cluster. We have represented the decoration of zigzag graphene nanoribbon with single copper atom and cluster containing two and three copper atoms. In all the cases, copper atoms tend to occupy the edge state. In addition, we have shown that copper can alter the current-voltage characteristic of zigzag graphene nanoribbon and create new fluctuations and negative differential resistance. These alternations are made due to discontinuity in the combination of orbitals along the graphene nanoribbon. Decoration alters these discontinuities and creates more visible fluctuations. However, in low bias voltages, the changes are similar in all the cases. The study demonstrates that in the decorated zigzag graphene nanoribbon, the edge states are the main states for transporting electron from one electrode to another.

  3. Real-time calibration of a feedback trap

    SciTech Connect

    Gavrilov, Momčilo; Jun, Yonggun; Bechhoefer, John

    2014-09-15

    Feedback traps use closed-loop control to trap or manipulate small particles and molecules in solution. They have been applied to the measurement of physical and chemical properties of particles and to explore fundamental questions in the non-equilibrium statistical mechanics of small systems. These applications have been hampered by drifts in the electric forces used to manipulate the particles. Although the drifts are small for measurements on the order of seconds, they dominate on time scales of minutes or slower. Here, we show that a recursive maximum likelihood (RML) algorithm can allow real-time measurement and control of electric and stochastic forces over time scales of hours. Simulations show that the RML algorithm recovers known parameters accurately. Experimental estimates of diffusion coefficients are also consistent with expected physical properties.

  4. Time-dependent density functional theory quantum transport simulation in non-orthogonal basis

    SciTech Connect

    Kwok, Yan Ho; Xie, Hang; Yam, Chi Yung; Chen, Guan Hua; Zheng, Xiao

    2013-12-14

    Basing on the earlier works on the hierarchical equations of motion for quantum transport, we present in this paper a first principles scheme for time-dependent quantum transport by combining time-dependent density functional theory (TDDFT) and Keldysh's non-equilibrium Green's function formalism. This scheme is beyond the wide band limit approximation and is directly applicable to the case of non-orthogonal basis without the need of basis transformation. The overlap between the basis in the lead and the device region is treated properly by including it in the self-energy and it can be shown that this approach is equivalent to a lead-device orthogonalization. This scheme has been implemented at both TDDFT and density functional tight-binding level. Simulation results are presented to demonstrate our method and comparison with wide band limit approximation is made. Finally, the sparsity of the matrices and computational complexity of this method are analyzed.

  5. Semianalytical quantum model for graphene field-effect transistors

    SciTech Connect

    Pugnaghi, Claudio; Grassi, Roberto Gnudi, Antonio; Di Lecce, Valerio; Gnani, Elena; Reggiani, Susanna; Baccarani, Giorgio

    2014-09-21

    We develop a semianalytical model for monolayer graphene field-effect transistors in the ballistic limit. Two types of devices are considered: in the first device, the source and drain regions are doped by charge transfer with Schottky contacts, while, in the second device, the source and drain regions are doped electrostatically by a back gate. The model captures two important effects that influence the operation of both devices: (i) the finite density of states in the source and drain regions, which limits the number of states available for transport and can be responsible for negative output differential resistance effects, and (ii) quantum tunneling across the potential steps at the source-channel and drain-channel interfaces. By comparison with a self-consistent non-equilibrium Green's function solver, we show that our model provides very accurate results for both types of devices, in the bias region of quasi-saturation as well as in that of negative differential resistance.

  6. Temperature dependence of Brillouin light scattering spectra of acoustic phonons in silicon

    SciTech Connect

    Olsson, Kevin S.; Klimovich, Nikita; An, Kyongmo; Sullivan, Sean; Weathers, Annie; Shi, Li E-mail: elaineli@physics.utexas.edu; Li, Xiaoqin E-mail: elaineli@physics.utexas.edu

    2015-02-02

    Electrons, optical phonons, and acoustic phonons are often driven out of local equilibrium in electronic devices or during laser-material interaction processes. The need for a better understanding of such non-equilibrium transport processes has motivated the development of Raman spectroscopy as a local temperature sensor of optical phonons and intermediate frequency acoustic phonons, whereas Brillouin light scattering (BLS) has recently been explored as a temperature sensor of low-frequency acoustic phonons. Here, we report the measured BLS spectra of silicon at different temperatures. The origins of the observed temperature dependence of the BLS peak position, linewidth, and intensity are examined in order to evaluate their potential use as temperature sensors for acoustic phonons.

  7. Modeling self-propagating exothermic reactions in multilayer systems

    SciTech Connect

    Jayaraman, S.; Mann, A.B.; Knio, O.M.; Van Heerden, D.; Bao, G.; Weihs, T.P.

    1998-12-31

    Self-propagating reactions in free-standing multilayer foils provide a unique opportunity to study very rapid, diffusion-based transformations in non-equilibrium material systems. To fully understand the coupling between mass and thermal diffusion controlling these reactions and to optimize the commercial use of reactive foils, the authors have undertaken analytical and numerical modeling. Their analytical model predicts an increase in the reaction velocities with decreasing bilayer thickness down to a critical bilayer thickness and a reversal in this trend below the critical thickness. Predicting reaction characteristics such as the flame thermal width, the reaction zone width and the effect of variations in material properties with temperature has proven analytically intractable. To overcome these limitations, the authors have also used numerical methods to determine the composition and temperature profiles ahead of the reaction front for different multilayer periods and premixing. The results are compared with experimental values where possible.

  8. Large linear magnetoresistance in a GaAs/AlGaAs heterostructure

    SciTech Connect

    Aamir, Mohammed Ali Goswami, Srijit Ghosh, Arindam; Baenninger, Matthias; Farrer, Ian; Ritchie, David A.; Tripathi, Vikram; Pepper, Michael

    2013-12-04

    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.

  9. Isotopic Soret effect in ternary mixtures: Theoretical predictions and molecular simulations

    SciTech Connect

    Artola, Pierre-Arnaud; Rousseau, Bernard

    2015-11-07

    In this paper, we study the Soret effect in ternary fluid mixtures of isotopic argon like atoms. Soret coefficients have been computed using non-equilibrium molecular dynamics and a theoretical approach based on our extended Prigogine model (with mass effect) and generalized to mixtures with any number of components. As is well known for binary mixture studies, the heaviest component always accumulates on the cold side whereas the lightest species accumulate on the hot side. An interesting behavior is observed for the species with the intermediate mass: it can accumulate on both sides, depending on composition and mass ratios. A simple picture can be given to understand this change of sign: the intermediate mass species can be seen as evolving in an equivalent fluid whose species mass varies with composition. An excellent prediction of all simulated data has been obtained using our model including the change of sign of the Soret coefficient for species with intermediate mass.

  10. Response to “Comment on ‘Twin symmetry texture of energetically condensed niobium thin films on sapphire substrate’ ” [J. Appl. Phys. 112, 016101 (2012)

    DOE PAGES [OSTI]

    Zhao, X.; Philips, L.; Reece, C. E.; Seo, Kang; Krishnan, M.; Valderrama, E.

    2012-07-01

    Welander is correct about the misidentified crystal-directions in the top-view sapphire lattice (Fig. 4 [Zhao et al., J. Appl. Phys. 110, 033523 (2011)]). He is also correct about the misorientation of the pole figures in Fig. 4. In Fig. 1 of this response, we have corrected these errors. Perhaps because of these errors, Welander misconstrued our discussion of the Nbcrystal growth as claiming a new 3D registry. That was not our intention. Rather, we wished to highlight the role of energetic condensation that drives low-defect crystal growth by a combination of non-equilibrium sub-plantation that disturbs the substrate lattice and thermalmore » annealing that annihilates defects and promotes large-grain crystal growth.« less

  11. Variational method for the minimization of entropy generation in solar cells

    SciTech Connect

    Smit, Sjoerd; Kessels, W. M. M.

    2015-04-07

    In this work, a method is presented to extend traditional solar cell simulation tools to make it possible to calculate the most efficient design of practical solar cells. The method is based on the theory of nonequilibrium thermodynamics, which is used to derive an expression for the local entropy generation rate in the solar cell, making it possible to quantify all free energy losses on the same scale. The framework of non-equilibrium thermodynamics can therefore be combined with the calculus of variations and existing solar cell models to minimize the total entropy generation rate in the cell to find the most optimal design. The variational method is illustrated by applying it to a homojunction solar cell. The optimization results in a set of differential algebraic equations, which determine the optimal shape of the doping profile for given recombination and transport models.

  12. Reversible monolayer-to-crystalline phase transition in amphiphilic silsesquioxane at the air-water interface

    DOE PAGES [OSTI]

    Banerjee, R.; Sanyal, M. K.; Bera, M. K.; Gibaud, A.; Lin, B.; Meron, M.

    2015-02-17

    We report on the counter intuitive reversible crystallisation of two-dimensional monolayer of Trisilanolisobutyl Polyhedral Oligomeric SilSesquioxane (TBPOSS) on water surface using synchrotron x-ray scattering measurements. Amphiphilic TBPOSS form rugged monolayers and Grazing Incidence X-ray Scattering (GIXS) measurements reveal that the in-plane inter-particle correlation peaks, characteristic of two-dimensional system, observed before transition is replaced by intense localized spots after transition. The measured x-ray scattering data of the non-equilibrium crystalline phase on the air-water interface could be explained with a model that assumes periodic stacking of the TBPOSS dimers. These crystalline stacking relaxes upon decompression and the TBPOSS layer retains its initialmore » monolayer state. The existence of these crystals in compressed phase is confirmed by atomic force microscopy measurements by lifting the materials on a solid substrate.« less

  13. Nanotube

    Energy Science and Technology Software Center

    2007-09-13

    This is a source code to calculate the current-voltage characteristics, the charge distribution and the electrostatic potential in carbon nanotube devices. The code utilizes the non-equilibrium Green's function method, implemented in a tight-binding scheme, to calculate the charge distribution and the energy-dependent transmission function, from which the current or the conductance are obtained. The electrostatic potential is obtained by solving Poisson's equation on a grid with boundary conditions on the electrodes, and at other interfaces.more » Self-consistency between the charge and the electrostatic potential is achieved using a linear mixing method. Different versions of the code allow the modeling of different types of nanotube devices: Version 1.0: Modeling of carbon nanotube electronic devices with cylindrical symmetry Version 1.1: Modeling of planar carbon nanotube electronic devices Version 1.2: Modeling of photocurrent in carbon nanotube devices« less

  14. Shot noise of charge current in a quantum dot responded by rotating and oscillating magnetic fields

    SciTech Connect

    Zhao, Hong-Kang Zou, Wei-Ke; Chen, Qiao

    2014-09-07

    We have investigated the shot noise and Fano factor of the dynamic spin-polarized quantum dot under the perturbations of a rotating magnetic field (RMF), and an oscillating magnetic field (OMF) by employing the non-equilibrium Green's function approach. The shot noise is enhanced from sub-Poissonian to super-Poissonian due to the application of RMF and OMF, and it is controlled sensitively by the tilt angle θ of RMF. The magnitude of shot noise increases as the photon energy ℏω of OMF increases, and its valley eventually is reversed to peaks as the photon energy is large enough. Double-peak structure of Fano factor is exhibited as the frequency of OMF increases to cover a large regime. The Zeeman energy μ{sub 0}B{sub 0} acts as an effective gate bias to exhibit resonant behavior, and novel peak emerges associated with the applied OMF.

  15. Flow induced migration in polymer melts – Theory and simulation

    SciTech Connect

    Dorgan, John Robert Rorrer, Nicholas Andrew

    2015-04-28

    Flow induced migration, whereby polymer melts are fractionated by molecular weight across a flow field, represents a significant complication in the processing of polymer melts. Despite its long history, such phenomena remain relatively poorly understood. Here a simple analytical theory is presented which predicts the phenomena based on well-established principles of non-equilibrium thermodynamics. It is unambiguously shown that for purely viscous materials, a gradient in shear rate is needed to drive migration; for purely viscometric flows no migration is expected. Molecular scale simulations of flow migration effects in dense polymer melts are also presented. In shear flow the melts exhibit similar behavior as the quiescent case; a constant shear rate across the gap does not induce chain length based migration. In comparison, parabolic flow causes profound migration for both unentangled and entangled melts. These findings are consistent with the analytical theory. The picture that emerges is consistent with flow induced migration mechanisms predominating over competing chain degradation mechanisms.

  16. Violation of the first law of black hole thermodynamics in f(T) gravity

    SciTech Connect

    Miao, Rong-Xin; Li, Miao; Miao, Yan-Gang E-mail: mli@itp.ac.cn

    2011-11-01

    We prove that, in general, the first law of black hole thermodynamics, ?Q = T?S, is violated in f(T) gravity. As a result, it is possible that there exists entropy production, which implies that the black hole thermodynamics can be in non-equilibrium even in the static spacetime. This feature is very different from that of f(R) or that of other higher derivative gravity theories. We find that the violation of first law results from the lack of local Lorentz invariance in f(T) gravity. By investigating two examples, we note that f''(0) should be negative in order to avoid the naked singularities and superluminal motion of light. When f''(T) is small, the entropy of black holes in f(T) gravity is approximatively equal to f'(T)/4 A.

  17. COSMIC-RAY-MEDIATED FORMATION OF BENZENE ON THE SURFACE OF SATURN'S MOON TITAN

    SciTech Connect

    Zhou Li; Zheng Weijun; Kaiser, Ralf I.; Landera, Alexander; Mebel, Alexander M.; Liang, Mao-Chang; Yung, Yuk L.

    2010-08-01

    The aromatic benzene molecule (C{sub 6}H{sub 6})-a central building block of polycyclic aromatic hydrocarbon molecules-is of crucial importance for the understanding of the organic chemistry of Saturn's largest moon, Titan. Here, we show via laboratory experiments and electronic structure calculations that the benzene molecule can be formed on Titan's surface in situ via non-equilibrium chemistry by cosmic-ray processing of low-temperature acetylene (C{sub 2}H{sub 2}) ices. The actual yield of benzene depends strongly on the surface coverage. We suggest that the cosmic-ray-mediated chemistry on Titan's surface could be the dominant source of benzene, i.e., a factor of at least two orders of magnitude higher compared to previously modeled precipitation rates, in those regions of the surface which have a high surface coverage of acetylene.

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

    SciTech Connect

    Liu, Shuanglong; Feng, Yuan Ping; Zhang, Chun; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543

    2013-11-21

    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.

  19. Accuracy of the Frensley inflow boundary condition for Wigner equations in simulating resonant tunneling diodes

    SciTech Connect

    Jiang Haiyan; Cai Wei; Tsu, Raphael

    2011-03-01

    In this paper, the accuracy of the Frensley inflow boundary condition of the Wigner equation is analyzed in computing the I-V characteristics of a resonant tunneling diode (RTD). It is found that the Frensley inflow boundary condition for incoming electrons holds only exactly infinite away from the active device region and its accuracy depends on the length of contacts included in the simulation. For this study, the non-equilibrium Green's function (NEGF) with a Dirichlet to Neumann mapping boundary condition is used for comparison. The I-V characteristics of the RTD are found to agree between self-consistent NEGF and Wigner methods at low bias potentials with sufficiently large GaAs contact lengths. Finally, the relation between the negative differential conductance (NDC) of the RTD and the sizes of contact and buffer in the RTD is investigated using both methods.

  20. Spin transport and spin polarization properties in double-stranded DNA

    SciTech Connect

    Simchi, Hamidreza; Esmaeilzadeh, Mahdi Mazidabadi, Hossein

    2013-11-21

    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.

  1. On the role of disorder on graphene and graphene nanoribbon-based vertical tunneling transistors

    SciTech Connect

    Ghobadi, Nayereh; Pourfath, Mahdi E-mail: pourfath@iue.tuwien.ac.at

    2014-11-14

    In this work, the characteristics of vertical tunneling field-effect transistors based on graphene (VTGFET) and graphene nanoribbon heterostructure (VTGNRFET) in the presence of disorder are theoretically investigated. An statistical analysis based on an atomistic tight-binding model for the electronic bandstructure along with the non-equilibrium Green's function formalism are employed. We study the dependence of the averaged density of states, transmission probability, on- and off-state conductances, on/off conductance ratio, and transfer characteristics on the substrate induced potential fluctuations and vacancies. In addition, the variabilities of the device characteristics due to the presence of disorder are evaluated. It can be inferred from the results that while introducing vacancies cause a relatively modest suppression of the transmission probability, potential fluctuations lead to the significant increase of transmission probability and conductance of the device. Moreover, the results show that the transport properties of VTGFET are more robust against disorder compared to VTGNRFET.

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

    SciTech Connect

    Simchi, Hamidreza; Esmaeilzadeh, Mahdi Mazidabadi, Hossein

    2014-01-28

    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.

  3. Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements

    SciTech Connect

    Niemi, K.; O'Connell, D.; Gans, T.; Oliveira, N. de; Joyeux, D.; Nahon, L.; Booth, J. P.

    2013-07-15

    Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N{sub 2}/O{sub 2} (4:1) admixtures. A maximum in the O-atom concentration of (9.1 {+-} 0.7) Multiplication-Sign 10{sup 20} m{sup -3} was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 {+-} 0.4) Multiplication-Sign 10{sup 19} m{sup -3} at 0.1 vol. %.

  4. Phase Transformations in Confined Nanosystems

    SciTech Connect

    Shield, Jeffrey E.; Belashchenko, Kirill

    2014-04-29

    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.

  5. Reversibility and criticality in amorphous solids

    SciTech Connect

    Regev, Ido; Weber, John; Reichhardt, Charles; Dahmen, Karin A.; Lookman, Turab

    2015-11-13

    The physical processes governing the onset of yield, where a material changes its shape permanently under external deformation, are not yet understood for amorphous solids that are intrinsically disordered. Here, using molecular dynamics simulations and mean-field theory, we show that at a critical strain amplitude the sizes of clusters of atoms undergoing cooperative rearrangements of displacements (avalanches) diverges. We compare this non-equilibrium critical behaviour to the prevailing concept of a ‘front depinning’ transition that has been used to describe steady-state avalanche behaviour in different materials. We explain why a depinning-like process can result in a transition from periodic to chaotic behaviour and why chaotic motion is not possible in pinned systems. As a result, these findings suggest that, at least for highly jammed amorphous systems, the irreversibility transition may be a side effect of depinning that occurs in systems where the disorder is not quenched.

  6. Reversibility and criticality in amorphous solids

    DOE PAGES [OSTI]

    Regev, Ido; Weber, John; Reichhardt, Charles; Dahmen, Karin A.; Lookman, Turab

    2015-11-13

    The physical processes governing the onset of yield, where a material changes its shape permanently under external deformation, are not yet understood for amorphous solids that are intrinsically disordered. Here, using molecular dynamics simulations and mean-field theory, we show that at a critical strain amplitude the sizes of clusters of atoms undergoing cooperative rearrangements of displacements (avalanches) diverges. We compare this non-equilibrium critical behaviour to the prevailing concept of a ‘front depinning’ transition that has been used to describe steady-state avalanche behaviour in different materials. We explain why a depinning-like process can result in a transition from periodic to chaoticmore » behaviour and why chaotic motion is not possible in pinned systems. As a result, these findings suggest that, at least for highly jammed amorphous systems, the irreversibility transition may be a side effect of depinning that occurs in systems where the disorder is not quenched.« less

  7. Expansion Potentials for Exact Far-from-Equilibrium Spreading of Particles and Energy

    SciTech Connect

    Vasseur, Romain; Karrasch, Christoph; Moore, Joel E.

    2015-12-01

    We report that the rates at which energy and particle densities move to equalize arbitrarily large temperature and chemical potential differences in an isolated quantum system have an emergent thermodynamical description whenever energy or particle current commutes with the Hamiltonian. Concrete examples include the energy current in the 1D spinless fermion model with nearest-neighbor interactions (XXZ spin chain), energy current in Lorentz-invariant theories or particle current in interacting Bose gases in arbitrary dimension. Even far from equilibrium, these rates are controlled by state functions, which we call "expansion potentials", expressed as integrals of equilibrium Drude weights. This relation between nonequilibrium quantities and linear response implies non-equilibrium Maxwell relations for the Drude weights. Lastly, we verify our results via DMRG calculations for the XXZ chain.

  8. Bifurcations and Patterns in Nonlinear Dissipative Systems

    SciTech Connect

    Guenter Ahlers

    2005-05-27

    This project consists of experimental investigations of heat transport, pattern formation, and bifurcation phenomena in non-linear non-equilibrium fluid-mechanical systems. These issues are studies in Rayleigh-B\\'enard convection, using both pure and multicomponent fluids. They are of fundamental scientific interest, but also play an important role in engineering, materials science, ecology, meteorology, geophysics, and astrophysics. For instance, various forms of convection are important in such diverse phenomena as crystal growth from a melt with or without impurities, energy production in solar ponds, flow in the earth's mantle and outer core, geo-thermal stratifications, and various oceanographic and atmospheric phenomena. Our work utilizes computer-enhanced shadowgraph imaging of flow patterns, sophisticated digital image analysis, and high-resolution heat transport measurements.

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

    SciTech Connect

    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)

    2014-07-15

    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.

  10. Grain orientations and grain boundaries in tungsten nonotendril fuzz grown under divertor-like conditions

    DOE PAGES [OSTI]

    Parish, Chad M.; Wang, Kun; Doerner, Russel P.; Baldwin, Matthew J.

    2016-09-19

    We grew nanotendril “fuzz” on tungsten via plasma exposure and performed transmission Kikuchi diffraction (tKD) in scanning electron microscopy of isolated nanotendrils. 900 °C, 1023 He/m2sec, 4 × 1026 He/m2 exposure of tungsten produced a deep and fully developed nanotendril mat. tKD of isolated nanotendrils indicated that there was no preferred crystallographic direction oriented along the long axes of the tendrils, and the grain boundary character showed slightly preferential orientations. In conclusion, tendril growth is sufficiently non-equilibrium to prevent any preference of growth direction to manifest measurably, and that new high-angle boundaries (with new grains and grain-growth axes) nucleate randomlymore » along the tendrils during growth.« less

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

    SciTech Connect

    Zhou, Z.; Rainforth, W. M.; Gass, M. H.; Bleloch, A.; Ehiassarian, A. P.; Hovsepian, P. Eh.

    2011-10-01

    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.

  12. Scanning tunneling spectroscopy of a magnetic atom on graphene in the Kondo regime

    DOE PAGES [OSTI]

    Zhuang, Huai -Bin; Sun, Qing -feng; Xie, X. C.

    2009-06-23

    In this study, the Kondo effect in the system consisting of a magnetic adatom on the graphene is studied. By using the non-equilibrium Green function method with the slave-boson mean field approximation, the local density of state (LDOS) and the conductance are calculated. For a doped graphene, the Kondo phase is present at all time. Surprisingly, two kinds of Kondo regimes are revealed. But for the undoped graphene, the Kondo phase only exists if the adatom’s energy level is beyond a critical value. The conductance is similar to the LDOS, thus, the Kondo peak in the LDOS can be observedmore » with the scanning tunneling spectroscopy. In addition, in the presence of a direct coupling between the STM tip and the graphene, the conductance may be dramatically enhanced, depending on the coupling site.« less

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

    SciTech Connect

    Hirst, L. C.; Walters, R. J.; Führer, M. F.; Ekins-Daukes, N. J.

    2014-06-09

    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.

  14. Computer modeling of Y-Ba-Cu-O thin film deposition and growth

    SciTech Connect

    Burmester, C.; Gronsky, R. ); Wille, L. . Dept. of Physics)

    1991-07-01

    The deposition and growth of epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7} are modeled by means of Monte Carlo simulations of the deposition and diffusion of Y, Ba, and Cu oxide particles. This complements existing experimental characterization techniques to allow the study of kinetic phenomena expected to play a dominant role in the inherently non-equilibrium thin film deposition process. Surface morphologies and defect structures obtained in the simulated films are found to closely resemble those observed experimentally. A systematic study of the effects of deposition rate and substrate temperature during in-situ film fabrication reveals that the kinetics of film growth can readily dominate the structural formation of the thin film. 16 refs., 4 figs.

  15. Expansion Potentials for Exact Far-from-Equilibrium Spreading of Particles and Energy

    DOE PAGES [OSTI]

    Vasseur, Romain; Karrasch, Christoph; Moore, Joel E.

    2015-12-01

    We report that the rates at which energy and particle densities move to equalize arbitrarily large temperature and chemical potential differences in an isolated quantum system have an emergent thermodynamical description whenever energy or particle current commutes with the Hamiltonian. Concrete examples include the energy current in the 1D spinless fermion model with nearest-neighbor interactions (XXZ spin chain), energy current in Lorentz-invariant theories or particle current in interacting Bose gases in arbitrary dimension. Even far from equilibrium, these rates are controlled by state functions, which we call "expansion potentials", expressed as integrals of equilibrium Drude weights. This relation between nonequilibriummore » quantities and linear response implies non-equilibrium Maxwell relations for the Drude weights. Lastly, we verify our results via DMRG calculations for the XXZ chain.« less

  16. THEORY OF A QUODON GAS WITH APPLICATION TO PRECIPITATION KINETICS IN SOLIDS UNDER IRRADIATION

    SciTech Connect

    Dubinko, Volodymyr; Shapovalov, Roman V.

    2014-06-17

    Rate theory of the radiation-induced precipitation in solids is modified with account of non-equilibrium fluctuations driven by the gas of lattice solitons (a.k.a. quodons) produced by irradiation. According to quantitative estimations, a steady-state density of the quodon gas under sufficiently intense irradiation can be comparable to the density of classical phonon gas. The modified rate theory is applied to modelling of copper precipitation in FeCu binary alloys under electron irradiation. In contrast to the classical rate theory, which disagrees strongly with experimental data on all precipitation parameters, the modified rate theory describes quite well both the evolution of precipitates and the matrix concentration of copper measured by different methods.

  17. Hydrocarbon sensors and materials therefor

    DOEpatents

    Pham, Ai Quoc; Glass, Robert S.

    2000-01-01

    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.

  18. The Intersection of Physics and Biology

    ScienceCinema

    Liphardt, Jan [University of California, Berkeley, California, United States

    2016-07-12

    In April 1953, Watson and Crick largely defined the program of 20th century biology: obtaining the blueprint of life encoded in the DNA. Fifty years later, in 2003, the sequencing of the human genome was completed. Like any major scientific breakthrough, the sequencing of the human genome raised many more questions than it answered. I'll brief you on some of the big open problems in cell and developmental biology, and I'll explain why approaches, tools, and ideas from the physical sciences are currently reshaping biological research. Super-resolution light microscopies are revealing the intricate spatial organization of cells, single-molecule methods show how molecular machines function, and new probes are clarifying the role of mechanical forces in cell and tissue function. At the same time, Physics stands to gain beautiful new problems in soft condensed matter, quantum mechanics, and non-equilibrium thermodynamics.

  19. Geometric universality of currents in an open network of interacting particles

    SciTech Connect

    Sinitsyn, Nikolai A; Chernyak, Vladimir Y; Chertkov, Michael

    2010-01-01

    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.

  20. Charting an Inflationary Landscape with Random Matrix Theory

    SciTech Connect

    Marsh, M.C. David; McAllister, Liam; Pajer, Enrico; Wrase, Timm E-mail: mcallister@cornell.edu E-mail: timm.wrase@stanford.edu

    2013-11-01

    We construct a class of random potentials for N >> 1 scalar fields using non-equilibrium random matrix theory, and then characterize multifield inflation in this setting. By stipulating that the Hessian matrices in adjacent coordinate patches are related by Dyson Brownian motion, we define the potential in the vicinity of a trajectory. This method remains computationally efficient at large N, permitting us to study much larger systems than has been possible with other constructions. We illustrate the utility of our approach with a numerical study of inflation in systems with up to 100 coupled scalar fields. A significant finding is that eigenvalue repulsion sharply reduces the duration of inflation near a critical point of the potential: even if the curvature of the potential is fine-tuned to be small at the critical point, small cross-couplings in the Hessian cause the curvature to grow in the neighborhood of the critical point.

  1. Luminescent Concentration of Diffuse Light

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ...acsphotonics.5b00334 Scientific Achievement Highest luminescent solar concentra1on ra1o to date achieved using tailor---made quantum dots and s pecially t uned p hotonic m irrors. ...

  2. SWiFT Research Program

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ... An operational deployment of near-real-time data portal and automatic data quality ... Design of rotors tailored for improved wind-plant performance. Baseline acoustic-beam-form...

  3. Add Blue | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Add Blue Jump to: navigation, search Name: Add Blue Place: Sao Paulo, Sao Paulo, Brazil Zip: 04621-000 Product: Company is tailoring US company KL Energy's enzymatic process...

  4. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... H. A. ; Marinak, M. M. Tailored, high-flux, multi-keV x-ray sources are desirable for studying x-ray interactions with matter for various civilian, space and military applications. ...

  5. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    Z Tailor R Sawakuchi G Flint D Beddar S Ibbott G The University of Texas MD Anderson Cancer Center Houston TX United States APPLIED LIFE SCIENCES ANIMALS DOSE RATES DOSEMETERS...

  6. Iran Thomas Auditorium, 8600

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    CNMS D D I I S S C C O O V V E E R R Y Y SEMINAR SERIES Abstract: We use molecular design, tailored syntheses, intermolecular interactions and selective chemistry to direct ...

  7. Executive Summary | Department of Energy

    Office of Environmental Management (EM)

    ... materials at the atomic-, nano-, and mesoscale to create new tailored functionalities. ... leads to function-from the atomic- and nano-scale to the meso-scale and beyond-and is ...

  8. I BN1",--44375 DE91

    Office of Scientific and Technical Information (OSTI)

    ... may be brought to an operational state and then added to the complement of instruments. ... may be tailored to individual site characteristics. 5. SITE SELECTION in response to the ...

  9. CX-010934: Categorical Exclusion Determination

    Energy.gov [DOE]

    Active, Tailorable Adhesives for Dissimilar Material Bonding, Repair and Reassembly CX(s) Applied: B3.6 Date: 09/18/2013 Location(s): Michigan Offices(s): National Energy Technology Laboratory

  10. CX-010935: Categorical Exclusion Determination

    Energy.gov [DOE]

    Active, Tailorable Adhesives for Dissimilar Material Bonding, Repair and Reassembly CX(s) Applied: B3.6 Date: 09/18/2013 Location(s): Michigan Offices(s): National Energy Technology Laboratory

  11. ITP Aluminum: Aluminum Industry Roadmap for the Automotive Market...

    Energy Saver

    ... compared to steel vehicles will continue to range from 500 to 700 gallons of gasoline. ... The production of tailor-welded blanks (TWBs) involves welding two or more separate sheets ...

  12. Manhattan Project: Production Reactor (Pile) Design, Met Lab...

    Office of Scientific and Technical Information (OSTI)

    ... The situation was tailor-made for a man with Groves's temperament. On October 5, Groves gave the Met Lab one week to decide. Even wrong decisions were better than no decisions, ...

  13. Guides: Design/Engineering for Deactivation & Decommissioning

    Energy.gov [DOE]

    To ensure development of appropriate levels of engineering detail, DOE-EM’s Office of Deactivation and Decommissioning and Facility Engineering (EM-13) has prepared this guidance for  tailoring a D...

  14. New Accelerator Will Study Steps on the Path to Fusion Power

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Accelerator Will Study Steps on the Path to Fusion Power New Accelerator Will Study Steps on the Path to Fusion Power Unusual Machine Tailor-made to Examine Heavy-ion Fusion May ...

  15. Fatty Acid Biosynthesis Caught in the Act | Stanford Synchrotron...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    elongation and tailoring steps on the growing fatty acid chain (Figure 1a)4. These steps are determined by AcpP-Fab enzyme interactions during which AcpP chooses the...

  16. CX-010298: Categorical Exclusion Determination

    Energy.gov [DOE]

    Tailoring Catalyst Composition and Architecture for Conversion of Pollutants from Low Temperature CX(s) Applied: A9, B3.6 Date: 05/02/2013 Location(s): Texas Offices(s): National Energy Technology Laboratory

  17. A Better Anode Design to Improve Lithium-Ion Batteries

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    ... The secret to the newly-designed anode is a tailored polymer that conducts electricity and ... At top, spectra of a series of polymers obtained with soft x-ray absorption spectroscopy ...

  18. Chris Benmore

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    aging of glassy pharmaceuticals made using acoustic levitation", C.J. Benmore, J.K.R. Weber, A.N. Tailor, B. Cherry, J.L. Yarger, Q.Mou, W. Weber, J. Neuefeind, S.R. Byrn. J....

  19. SU-E-T-368: Effect of a Strong Magnetic Field On Select Radiation...

    Office of Scientific and Technical Information (OSTI)

    a magnetic fields similar to those produced by a MRI-linac system. Elekta-MD Anderson Cancer Center Research Agreement. less Authors: Mathis, M ; Wen, Z ; Tailor, R ;...

  20. SECRETARY OF ENERGY ADVISORY BOARD

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    The board wants to bring to your attention the valuable nature of these programs to the U.S. scientific community. We write to urge continuing support for these few, tailored ...