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We encourage you to perform a real-time search of NLEBeta
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1

Molecular Dynamics Investigation of Ferrous-Ferric Electron Transfer...  

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

Electron Transfer in a Hydrolyzing Aqueous Solution: Calculation of the pH Molecular Dynamics Investigation of Ferrous-Ferric Electron Transfer in a Hydrolyzing Aqueous Solution:...

2

PIA - Savannah River Nuclear Solutions Electronic Safeguards...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Solutions Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions...

3

Nonadiabatic dynamics of electron transfer in solution: Explicit and implicit solvent treatments that include multiple relaxation time scales  

SciTech Connect (OSTI)

The development of efficient theoretical methods for describing electron transfer (ET) reactions in condensed phases is important for a variety of chemical and biological applications. Previously, dynamical dielectric continuum theory was used to derive Langevin equations for a single collective solvent coordinate describing ET in a polar solvent. In this theory, the parameters are directly related to the physical properties of the system and can be determined from experimental data or explicit molecular dynamics simulations. Herein, we combine these Langevin equations with surface hopping nonadiabatic dynamics methods to calculate the rate constants for thermal ET reactions in polar solvents for a wide range of electronic couplings and reaction free energies. Comparison of explicit and implicit solvent calculations illustrates that the mapping from explicit to implicit solvent models is valid even for solvents exhibiting complex relaxation behavior with multiple relaxation time scales and a short-time inertial response. The rate constants calculated for implicit solvent models with a single solvent relaxation time scale corresponding to water, acetonitrile, and methanol agree well with analytical theories in the Golden rule and solvent-controlled regimes, as well as in the intermediate regime. The implicit solvent models with two relaxation time scales are in qualitative agreement with the analytical theories but quantitatively overestimate the rate constants compared to these theories. Analysis of these simulations elucidates the importance of multiple relaxation time scales and the inertial component of the solvent response, as well as potential shortcomings of the analytical theories based on single time scale solvent relaxation models. This implicit solvent approach will enable the simulation of a wide range of ET reactions via the stochastic dynamics of a single collective solvent coordinate with parameters that are relevant to experimentally accessible systems.

Schwerdtfeger, Christine A.; Soudackov, Alexander V.; Hammes-Schiffer, Sharon, E-mail: shs3@illinois.edu [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)] [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)

2014-01-21T23:59:59.000Z

4

Electronic Spectroscopy & Dynamics  

SciTech Connect (OSTI)

The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

Mark Maroncelli, Nancy Ryan Gray

2010-06-08T23:59:59.000Z

5

Fissile solution dynamics: Student research  

SciTech Connect (OSTI)

There are two research projects in criticality safety at the University of Arizona: one in dynamic simulation of hypothetical criticality accidents in fissile solutions, and one in criticality benchmarks using transport theory. We have used the data from nuclear excursions in KEWB, CRAC, and SILENE to help in building models for solution excursions. An equation of state for liquids containing gas bubbles has been developed and coupled to point-reactor dynamics in an attempt to predict fission rate, yield, pressure, and kinetic energy. It appears that radiolytic gas is unimportant until after the first peak, but that it does strongly affect the shape of the subsequent power decrease and also the dynamic pressure.

Hetrick, D.L.

1994-09-01T23:59:59.000Z

6

Dynamic imaging with electron microscopy  

SciTech Connect (OSTI)

Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.

Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

2014-02-20T23:59:59.000Z

7

Dynamic imaging with electron microscopy  

ScienceCinema (OSTI)

Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.

Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

2014-05-30T23:59:59.000Z

8

PIA - Savannah River Nuclear Solution SRNS Electronic Document...  

Office of Environmental Management (EM)

Electronic Document Workflow RECORDS System (EDWS) PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow RECORDS System (EDWS) PIA - Savannah River Nuclear...

9

Dynamics of soft Nanomaterials captured by transmission electron...  

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

Dynamics of soft Nanomaterials captured by transmission electron microscopy in liquid water. Dynamics of soft Nanomaterials captured by transmission electron microscopy in liquid...

10

Organoactinide chemistry: synthesis, structure, and solution dynamics  

SciTech Connect (OSTI)

This thesis considers three aspects of organoactinide chemistry. In chapter one, a bidentate phosphine ligand was used to kinetically stabilize complexes of the type Cp/sub 2/MX/sub 2/. Ligand redistribution processes are present throughout the synthetic work, as has often been observed in uranium cyclopentadienyl chemistry. The effects of covalent M-L bonding on the solution and solid state properties of U(III) coordination complexes are considered. In particular, the nature of the more subtle interaction between the metal and the neutral ligand are examined. Using relative basicity data obtained in solution, and solid state structural data (and supplemented by gas phase photoelectron measurements), it is demonstrated that the more electron rich U(III) centers engage in significant U ..-->.. L ..pi..-donation. Trivalent uranium is shown to be capable of acting either as a one- or two-electron reducing agent toward a wide variety of unsaturated organic and inorganic molecules, generating molecular classes unobtainable via traditional synthetic approaches, as well as offering an alternative synthetic approach to molecules accessible via metathesis reactions. Ligand redistribution processes are again observed, but given the information concerning ligand lability, this reactivity pattern is applied to the synthesis of pure materials inaccessible from redox chemistry. 214 refs., 33 figs., 10 tabs.

Brennan, J.G.

1985-12-01T23:59:59.000Z

11

Brownian Dynamics Simulation of Protein Solutions: Structural and Dynamical Properties  

SciTech Connect (OSTI)

The study of solutions of biomacromolecules provides an important basis for understanding the behavior of many fundamental cellular processes, such as protein folding, self-assembly, biochemical reactions, and signal transduction. Here, we describe a Brownian dynamics simulation procedure and its validation for the study of the dynamic and structural properties of protein solutions. In the model used, the proteins are treated as atomically detailed rigid bodies moving in a continuum solvent. The protein-protein interaction forces are described by the sum of electrostatic interaction, electrostatic desolvation, nonpolar desolvation, and soft-core repulsion terms. The linearized Poisson-Boltzmann equation is solved to compute electrostatic terms. Simulations of homogeneous solutions of three different proteins with varying concentrations, pH, and ionic strength were performed. The results were compared to experimental data and theoretical values in terms of long-time self-diffusion coefficients, second virial coefficients, and structure factors. The results agree with the experimental trends and, in many cases, experimental values are reproduced quantitatively. There are no parameters specific to certain protein types in the interaction model, and hence the model should be applicable to the simulation of the behavior of mixtures of macromolecules in cell-like crowded environments.

Mereghetti, Paolo; Gabdoulline, Razif; Wade, Rebecca C.

2010-12-01T23:59:59.000Z

12

Electronic forms solutions To support your business objectives  

E-Print Network [OSTI]

Electronic forms solutions To support your business objectives Easily integrate your offline forms are using electronic forms instead of paper, so that their existing forms are always in stock, easy to locate and have a consistent look and feel. IBM® Lotus® Forms software provides an open electronic forms

13

Brownian Dynamics Model of Excited-State Relaxation in Solutions of Conjugated Oligomers  

E-Print Network [OSTI]

1 Brownian Dynamics Model of Excited-State Relaxation in Solutions of Conjugated Oligomers Nicolae, Pittsburgh, Pennsylvania 15213. Excited state relaxation, conjugated polymers, Brownian dynamics. The effects, of the oligomer. A simple molecular mechanical form is used for the ground electronic state. The excitation energy

Yaron, David

14

AdS String: Classical Solutions and Moduli Dynamics  

E-Print Network [OSTI]

We review some recent work and techniques for constructing dynamical string solutions in AdS spacetime. These solutions generalize the folded string and multi-spike solutions of GKP and Kruczenski. The methods developed for constructing these dynamical solutions are based on Pohlmeyer reduction to integrable sinh-Gordon type equations. The integrability of the equations is seen as the crucial tool for reconstruction of the string configurations. We discuss the physical meaning of these dynamical spike solutions and the question of their moduli space.

Antal Jevicki; Kewang Jin

2010-01-29T23:59:59.000Z

15

Electron dynamics in surface acoustic wave devices  

E-Print Network [OSTI]

-dimensional nanostructures one can create a series of dynamic quantum dots corresponding to the minima of the travelling electric wave, and each dot carries a single electron at the SAW velocity (? 2800 m/s). These devices may be of use in developing future quantum...

Thorn, Adam Leslie

2009-10-13T23:59:59.000Z

16

Bistable solutions for the electron energy distribution function in electron swarms in xenon via Boltzmann equation analysis and particle simulations  

E-Print Network [OSTI]

At low reduced electric fields the electron energy distribution function in heavy noble gases can take two distinct shapes. This bistability effect - in which electron-electron (Coulomb) collisions play an essential role - is analyzed here with a Boltzmann equation approach and with a first principles particle simulation method. The latter is based on a combination of a molecular dynamics technique that accounts for the many-body interaction within the electron gas and a Monte Carlo treatment of the collisions between electrons and the background gas atoms. The good agreement found between the results of the two techniques confirms the existence of the two different stable solutions for the EEDF under swarm conditions at low electric fields.

Dyatko, Nikolay

2015-01-01T23:59:59.000Z

17

Photoinduced electron transfer processes in homogeneous and microheterogeneous solutions  

SciTech Connect (OSTI)

The studies have focused on rapid, efficient bond-fragmentation reactions initiated through photoinduced electron transfer. Electron transfer induced fragmentation of a number of donors have been examined, especially 1,2 diamines and related compounds. Two of the amines fragment with rate constants of 3 [times] 10[sup 8] to 2 [times] 10[sup 9] M[sup [minus]1]sec[sup [minus]1]. A series of amino-substituted pinacols and related compounds have also been examined; they undergo similar but slower fragmentation processes when converted to their cation radicals by photoinduced electron transfer. The studies with linked and polymeric electron donor- electron acceptor coupled molecules have also progressed. Several polymers containing diamine repeat units and anthraquinone or nitroaromatic acceptors have also been prepared that can be photoactivated by visible irradiation; they fragment efficiently in solution and photodegrade even in the solid state. The studies of singlet oxygen initiated fragmentation reactions of diamines, amino alcohols, and aminoketones have nearly been completed. Attention have been turned to fragmentable electron acceptors such as p- cyanobenzyl bromide; irradiation of electron donors such as methyl- or methoxy-naphthalenes can initiate efficient fragmentation of the electron deficient bromide.

Whitten, D.G.

1992-12-01T23:59:59.000Z

18

Hydration structure of salt solutions from ab initio molecular dynamics  

SciTech Connect (OSTI)

The solvation structures of Na{sup +}, K{sup +}, and Cl{sup -} ions in aqueous solution have been investigated using density functional theory (DFT) based Car-Parrinello (CP) molecular dynamics (MD) simulations. CPMD trajectories were collected for systems containing three NaCl or KCl ion pairs solvated by 122 water molecules using three different but commonly employed density functionals (BLYP, HCTH, and PBE) with electron correlation treated at the level of the generalized gradient approximation (GGA). The effect of including dispersion forces was analyzed through the use of an empirical correction to the DFT-GGA scheme. Special attention was paid to the hydration characteristics, especially the structural properties of the first solvation shell of the ions, which was investigated through ion-water radial distribution functions, coordination numbers, and angular distribution functions. There are significant differences between the present results obtained from CPMD simulations and those provided by classical MD based on either the CHARMM force field or a polarizable model. Overall, the computed structural properties are in fair agreement with the available experimental results. In particular, the observed coordination numbers 5.0-5.5, 6.0-6.4, and 6.0-6.5 for Na{sup +}, K{sup +}, and Cl{sup -}, respectively, are consistent with X-ray and neutron scattering studies but differ somewhat from some of the many other recent computational studies of these important systems. Possible reasons for the differences are discussed.

Bankura, Arindam; Carnevale, Vincenzo; Klein, Michael L. [Institute for Computational Molecular Science and Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States)

2013-01-07T23:59:59.000Z

19

Dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons  

SciTech Connect (OSTI)

The dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons has been investigated in the framework of perturbed and non-perturbed Kadomtsev-Petviashili (KP) equations. Applying the reductive perturbation technique, we have derived the KP equation in electron-positron-ion magnetoplasma with kappa distributed electrons and positrons. Bifurcations of ion acoustic traveling waves of the KP equation are presented. Using the bifurcation theory of planar dynamical systems, the existence of the solitary wave solutions and the periodic traveling wave solutions has been established. Two exact solutions of these waves have been derived depending on the system parameters. Then, using the Hirota's direct method, we have obtained two-soliton and three-soliton solutions of the KP equation. The effect of the spectral index ? on propagations of the two-soliton and the three-soliton has been shown. Considering an external periodic perturbation, we have presented the quasi periodic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas.

Saha, Asit, E-mail: asit-saha123@rediffmail.com, E-mail: prasantachatterjee1@rediffmail.com [Department of Mathematics, Sikkim Manipal Institute of Technology, Majitar, Rangpo, East-Sikkim 737136 (India); Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India); Pal, Nikhil; Chatterjee, Prasanta, E-mail: asit-saha123@rediffmail.com, E-mail: prasantachatterjee1@rediffmail.com [Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India)

2014-10-15T23:59:59.000Z

20

Electronic and Magnetization Dynamics of Cobalt Substituted Iron Oxide Nanocrystals  

E-Print Network [OSTI]

Knowledge of energy dissipation and relaxation in electron, spin, and lattice degrees of freedom is of fundamental importance from both a technological and scientific point of view. In this dissertation, the electronic and magnetization dynamics...

Chen, Tai-Yen

2011-02-22T23:59:59.000Z

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


21

Multi-basin dynamics of a protein in aqueous solution  

SciTech Connect (OSTI)

A molecular dynamics simulation of crambin in aqueous solution shows that motions are characteristic of non-linear systems. The authors describe typical non-linear excitations, such as intermittency, for various representations of the protein dynamics and structure. The protein backbone dihedral angles show fast correlated transitions from one minimum well to another. Each transition is followed by small overdamped oscillations. Equal-time cross correlations of all ({phi},{psi}) angles show that correlations are extended along the backbone chain. An analysis based on a generalized least squares fitting of the protein fluctuations along vectors show that a small set of molecule optimal dynamic coordinates (MODC) describe most of the protein fluctuations. In addition, the MODC describe a trajectory where the protein conformation jumps from one minimum well to another. An extension of the MODC describing 2- and 3-dimensional cuts of the protein configurational space clearly shows a trajectory around multiple basins of attraction.

Garcia, A.E. [Los Alamos National Lab., NM (United States). Theoretical Biology and Biophysics Group

1994-10-01T23:59:59.000Z

22

On the construction and properties of weak solutions describing dynamic cavitation  

E-Print Network [OSTI]

On the construction and properties of weak solutions describing dynamic cavitation (In: Journal associated with dynamically cavitating solutions coincides with the critical stretching in the bifurcation with contents. Keywords: Cavitation, Shock wave, Polyconvex elasticity Mathematics Subject Classification: 35L67

Miroshnikov, Alexey

23

Energetics and Dynamics of Electron Transfer and Proton Transfer...  

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

Transfer in Dissociation of Metal III (salen)-Peptide Complexes in the Energetics and Dynamics of Electron Transfer and Proton Transfer in Dissociation of Metal III (salen)-Peptide...

24

Chemical Dynamics at Metal Surfaces: The Role of Electronic Excitation...  

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

Chemical Dynamics at Metal Surfaces: The Role of Electronic Excitations Mar 06 2015 11:00 AM - 12:00 PM John Tully, Yale University, New Haven, Connecticut Joint Institute for...

25

Electron Transfer Dynamics in Photocatalytic CO2 Conversion ...  

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

Electron Transfer Dynamics in Photocatalytic CO2 Conversion Sep 2014 Aug 2014 Jul 2014 June 2014 May 2014 Apr 2014 Mar 2014 Feb 2014 Jan 2014 Dec 2013 Nov 2013 Oct 2013 Sep 2013...

26

Structure and dynamics of aqueous solution of uranyl ions  

SciTech Connect (OSTI)

The present work describes a molecular dynamics simulation study of structure and dynamics of aqueous solution of uranyl ions in water. Structural properties of the system in terms of radial distribution functions and dynamical characteristics as obtained through velocity autocorrelation function and mean square displacements have been analyzed. The results for radial distribution functions show the oxygen of water to form the first solvation shell at 2.4 around the uranium atom, whereas the hydrogen atoms of water are distributed around the uranium atom with the major peak at around 3.0 . Analyses of transport behaviors of ions and water through MSD indicates that the diffusion of the uranyl ion is much less as compared to that of the water molecules. It is also observed that the dynamical behavior of water molecules gets modified due to the presence of uranyl ion. The effect of increase in concentration of uranyl ions on the structure and dynamics of water molecules is also studied.

Chopra, Manish [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Choudhury, Niharendu, E-mail: nihcho@barc.gov.in [Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai-400085 (India)

2014-04-24T23:59:59.000Z

27

Controlling attosecond electron dynamics by phase-stabilized polarization gating  

E-Print Network [OSTI]

LETTERS Controlling attosecond electron dynamics by phase-stabilized polarization gating I. J. SOLA the signature of a single return of the electron wavepacket over a large range of energies. This temporally (low energy) and cut-off (high energy) harmonics, specific focusing conditions ensure that only

Loss, Daniel

28

Molecular Dynamics Simulations of Solutions at Constant Chemical Potential  

E-Print Network [OSTI]

Molecular Dynamics studies of chemical processes in solution are of great value in a wide spectrum of applications, that range from nano-technology to pharmaceutical chemistry. However, these calculations are affected by severe finite-size effects, such as the solution being depleted as the chemical process proceeds, that influence the outcome of the simulations. To overcome these limitations, one must allow the system to exchange molecules with a macroscopic reservoir, thus sampling a Grand-Canonical ensemble. Despite the fact that different remedies have been proposed, this still represents a key challenge in molecular simulations. In the present work we propose the C$\\mu$MD method, which introduces an external force that controls the environment of the chemical process of interest. This external force, drawing molecules from a finite reservoir, maintains the chemical potential constant in the region where the process takes place. We have applied the C$\\mu$MD method to the paradigmatic case of urea crystall...

Perego, Claudio; Parrinello, Michele

2015-01-01T23:59:59.000Z

29

Electron Dynamics in Nanostructures in Strong Laser Fields  

SciTech Connect (OSTI)

The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.

Kling, Matthias

2014-09-11T23:59:59.000Z

30

Neutrino-electron scattering and the choice between different MSW solutions of the solar neutrino problem  

SciTech Connect (OSTI)

We consider the scattering of solar neutrinos by electrons as a means for distinguishing between MSW solutions of the solar neutrino problem. In terms of the ratio R between the observed cross-section and that for pure electron-type neutrinos, we find that some correlation between the value R and the appropriate solution. 9 refs., 3 figs.

Rosen, S.P.; Gelb, J.M.

1987-01-01T23:59:59.000Z

31

Photoinduced electron transfer processes in homogeneous and microheterogeneous solutions  

SciTech Connect (OSTI)

The focus of the work described in this report is on single electron transfer reactions of excited states which culminate in the formation of stable or metastable even electron species. For the most part the studies have involved even electron organic substrates which are thus converted photochemically to odd electron species and then at some stage reconvert to even electron products. These reactions generally fall into two rather different categories. In one set of studies we have examined reactions in which the metastable reagents generated by single electron transfer quenching of an excited state undergo novel fragmentation reactions, chiefly involving C-C bond cleavage. These reactions often culminate in novel and potentially useful chemical reactions and frequently have the potential for leading to new chemical products otherwise unaffordable by conventional reaction paths. In a rather different investigation we have also studied reactions in which single electron transfer quenching of an excited state is followed by subsequent reactions which lead reversibly to metastable two electron products which, often stable in themselves, can nonetheless be reacted with each other or with other reagents to regenerate the starting materials with release of energy. 66 refs., 9 figs., 1 tab.

Whitten, D.G.

1991-10-01T23:59:59.000Z

32

Solution of simultaneous partial differential equations using dynamic ADI: Solution of the streamlined Darwin field equations  

SciTech Connect (OSTI)

We apply a particular version of ADI called Dynamic ADI (DADI) to the strongly coupled 2nd-order partial differential equations that arise from the streamlined Darwin field (SDF) equations. The DADI method a applied in a form that we show is guaranteed to converge to the desired solution of the finite difference equation. We give overviews of our test case, the SDF problem and the DADI method, with some justification for our choice of operator splitting. Finally, we apply DADI to the strongly coupled SDF equations and present the results from our test case. Our implementation requires a factor of 7 less storage and has proven to be a factor of 4 (in the worst case) to several orders of magnitude faster than competing methods. 13 refs., 3 figs., 5 tabs.

Hewett, D.W.; Larson, D.J.; Doss, S. (Lawrence Livermore National Lab., Livermore, CA (United States))

1992-07-01T23:59:59.000Z

33

Integrating Security Solutions to Support nanoCMOS Electronics Research .  

E-Print Network [OSTI]

??The UK Engineering and Physical Sciences Research Council (EPSRC) funded Meeting the Design Challenges of nanoCMOS Electronics (nanoCMOS) is developing a research infrastructure for collaborative (more)

SINNOTT, RICHARD

2008-01-01T23:59:59.000Z

34

Trajectory-Wave Approach to Electron Dynamics in Hydrogen Atom  

E-Print Network [OSTI]

In this work we propose a new approach to the explanation of the nature of electron based on the corpuscular-wave monism using the further development of the optical-mechanical analogy to describe the physical reality. In this theory the motion of an electron is considered to occur along a trajectory the presence of which is a reflection of the existence of a particle, as well as it is assumed that any motion is defined by a wave V(x,t). It is assumed that there is an explicit relationship between the trajectory and wave equations of the electron, which are established on the basis of the local variational principle. In this approach, an electron wave propagating in free space takes along the electron trajectory. We used this theory to describe the electron motion in a hydrogen-like atom and found its stationary states. The energies of these states coincide with the known quantum mechanics solutions for the stationary energies of the hydrogen-like atom, however, in our approach the spatial trajectories of the electron have the form of the surfaces, which are formed in the region of nodes of the standing electron wave. These surfaces have the form of spheres for the spherical symmetrical electron states and the radii of these spheres coincide with the radii of the Bohr orbits of these states. Thus, in this approach the trajectory and wave measurements of the electron get a consistent spatial description that is inherent to the picture of the corpuscular-wave monism. We discuss the considerable correspondence of the proposed theory with the quantum mechanics results describing the stationary and non-stationary motions of the electron in the atom and their difference. We believe that measuring of the spatial configuration of the observed electron trajectory surfaces in an atom could be a deep examination of the standard quantum theory.

N. T. Valishin; F. T. Valishin; S. A. Moiseev

2011-02-08T23:59:59.000Z

35

Photocathode Optimization for a Dynamic Transmission Electron Microscope: Final Report  

SciTech Connect (OSTI)

The Dynamic Transmission Electron Microscope (DTEM) team at Harvey Mudd College has been sponsored by LLNL to design and build a test setup for optimizing the performance of the DTEM's electron source. Unlike a traditional TEM, the DTEM achieves much faster exposure times by using photoemission from a photocathode to produce electrons for imaging. The DTEM team's work is motivated by the need to improve the coherence and current density of the electron cloud produced by the electron gun in order to increase the image resolution and contrast achievable by DTEM. The photoemission test setup is nearly complete and the team will soon complete baseline tests of electron gun performance. The photoemission laser and high voltage power supply have been repaired; the optics path for relaying the laser to the photocathode has been finalized, assembled, and aligned; the internal setup of the vacuum chamber has been finalized and mostly implemented; and system control, synchronization, and data acquisition has been implemented in LabVIEW. Immediate future work includes determining a consistent alignment procedure to place the laser waist on the photocathode, and taking baseline performance measurements of the tantalum photocathode. Future research will examine the performance of the electron gun as a function of the photoemission laser profile, the photocathode material, and the geometry and voltages of the accelerating and focusing components in the electron gun. This report presents the team's progress and outlines the work that remains.

Ellis, P; Flom, Z; Heinselman, K; Nguyen, T; Tung, S; Haskell, R; Reed, B W; LaGrange, T

2011-08-04T23:59:59.000Z

36

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

built, and each have been used by researchers from labs in New York. Learn More California Lithium Battery, Inc. Argonne National Laboratory 626 likes California Lithium...

37

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

include transport and stationery power plants, marine, cars and trucks. Learn More California Lithium Battery, Inc. Argonne National Laboratory 626 likes California Lithium...

38

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

to existing buildings with costs comparable to conventional HVAC. Learn More California Lithium Battery, Inc. Argonne National Laboratory 626 likes California Lithium...

39

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

is developing a low-cost, advanced lithium-ion battery that employs a novel silicon graphene composite material that will substantially improve battery cycle life. When combined...

40

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergyENERGYWomentheATLANTA,Fermi NationalBusiness PlanPostingOctoberof Energy U.S. goal to333

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


41

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana.ProgramJulietipDepartmentJune 20, 2012 The12,1, 2005ForCONFERENCELandfill7AC

42

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana.ProgramJulietipDepartmentJune 20, 2012 The12,1,

43

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana.ProgramJulietipDepartmentJune 20, 2012 The12,1,TrakLok Corporation Oak Ridge

44

Integrated Dynamic Electron Solutions, Inc. | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana.ProgramJulietipDepartmentJune 20, 2012 The12,1,TrakLok Corporation Oak

45

Solution to Submit Large Electronic Proposal Files Principal Investigator and Departmental Staff Procedures  

E-Print Network [OSTI]

Procedures Sponsored Projects Administration (SPA) now has a solution for large electronic proposal files Submission folder. They can only upload files. 9. Follow the normal procedures to advise SPA to submit the sponsor's procedures. #12;

Janssen, Michel

46

New analytical solutions for dust acoustic solitary and periodic waves in an unmagnetized dusty plasma with kappa distributed electrons and ions  

SciTech Connect (OSTI)

Dust acoustic solitary waves and periodic waves in an unmagnetized dusty plasma with kappa distributed electrons and ions are investigated through non-perturbative approach. Basic equations are reduced to a system of ordinary differential equations involving electrostatic potential. After that by applying the bifurcation theory of planar dynamical systems to this system, we have studied the existence of solitary wave solutions and periodic wave solutions. New analytical solutions for the above waves are derived depending on the parametric space. Regarding the solitary and periodic wave solutions, the combined effects of temperature ratio (?) of ions and electrons, spectral index (?) and density ratio (p) are studied on characteristics of dust acoustic (DA) solitary waves and periodic waves. The spectral index (?), density ratio (p) of ions and electrons and temperature ratio (?) significantly influence the characteristics of dust acoustic solitary and periodic structures.

Saha, Asit, E-mail: asit-saha123@rediffmail.com [Department of Mathematics, Sikkim Manipal Institute of Technology, Majitar, Rangpo, East-Sikkim 737136 (India) [Department of Mathematics, Sikkim Manipal Institute of Technology, Majitar, Rangpo, East-Sikkim 737136 (India); Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India); Chatterjee, Prasanta, E-mail: prasantachatterjee1@rediffmail.com [Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India)] [Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India)

2014-02-15T23:59:59.000Z

47

Business Commitments for Dynamic E-business Solution Management: Concept and Specification  

E-Print Network [OSTI]

Business Commitments for Dynamic E-business Solution Management: Concept and Specification Haifei 134 Yorktown Heights, NY 10598, USA ABSTRACT Nowadays, enterprises have treated e-business as an integral part of their daily business operations. How to manage a dynamic e-business solution

Li, Haifei

48

RIS probed dynamical effects in two-electron barium atom  

SciTech Connect (OSTI)

We present for Ba Nsnl planetary states an energy level analysis in order to yield values for the Ba{sup +} Ns core polarizabilities. The parametrized effective dipole and quadrupole values extracted from our data for N=7-10 are compared to calculated ones using a static model. Dipole polarizabilities show very close similarities with static values and at the opposite quadrupole polarizabilities exhibit larger discrepancies. These give evidence of non-adiabatic effects between the two asymmetrically excited electrons which are attributed to the increasing strength of dynamical effects on the Ns electron caused by the motion of the outer nl one.

Camus, Pierre; Cohen, Samuel [Laboratoire Aime Cotton, Centre National de la Recherche Scientifique II, Batiment 505, Campus d'Orsay, 91405 Orsay Cedex (France)

1995-04-01T23:59:59.000Z

49

Probing Electron Transfer Dynamics at MgO Surfaces by Mg-Atom...  

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

Electron Transfer Dynamics at MgO Surfaces by Mg-Atom Desorption. Probing Electron Transfer Dynamics at MgO Surfaces by Mg-Atom Desorption. Abstract: Desorption of a weakly bound...

50

Multiconfiguration time-dependent Hartree-Fock treatment of electronic and nuclear dynamics in diatomic molecules  

SciTech Connect (OSTI)

The multiconfiguration time-dependent Hartree-Fock (MCTDHF) method is formulated for treating the coupled electronic and nuclear dynamics of diatomic molecules without the Born-Oppenheimer approximation. The method treats the full dimensionality of the electronic motion, uses no model interactions, and is in principle capable of an exact nonrelativistic description of diatomics in electromagnetic fields. An expansion of the wave function in terms of configurations of orbitals whose dependence on internuclear distance is only that provided by the underlying prolate spheroidal coordinate system is demonstrated to provide the key simplifications of the working equations that allow their practical solution. Photoionization cross sections are also computed from the MCTDHF wave function in calculations using short pulses.

Haxton, D. J.; Lawler, K. V. [Chemical Sciences and Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); McCurdy, C. W. [Chemical Sciences and Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); Departments of Applied Science and Chemistry, Davis, California, 95616 (United States)

2011-06-15T23:59:59.000Z

51

Electron-nuclear correlations for photo-induced dynamics in molecular dimers  

E-Print Network [OSTI]

January 2004; accepted 11 March 2004 Ultrafast photoinduced dynamics of electronic excitation in molecularElectron-nuclear correlations for photo-induced dynamics in molecular dimers Dmitri S. Kilin, Yuri dimers is drastically affected by the dynamic reorganization of inter- and intra- molecular nuclear

52

Charge constrained density functional molecular dynamics for simulation of condensed phase electron transfer reactions  

SciTech Connect (OSTI)

We present a plane-wave basis set implementation of charge constrained density functional molecular dynamics (CDFT-MD) for simulation of electron transfer reactions in condensed phase systems. Following the earlier work of Wu and Van Voorhis [Phys. Rev. A 72, 024502 (2005)], the density functional is minimized under the constraint that the charge difference between donor and acceptor is equal to a given value. The classical ion dynamics is propagated on the Born-Oppenheimer surface of the charge constrained state. We investigate the dependence of the constrained energy and of the energy gap on the definition of the charge and present expressions for the constraint forces. The method is applied to the Ru{sup 2+}-Ru{sup 3+} electron self-exchange reaction in aqueous solution. Sampling the vertical energy gap along CDFT-MD trajectories and correcting for finite size effects, a reorganization free energy of 1.6 eV is obtained. This is 0.1-0.2 eV lower than a previous estimate based on a continuum model for solvation. The smaller value for the reorganization free energy can be explained by the fact that the Ru-O distances of the divalent and trivalent Ru hexahydrates are predicted to be more similar in the electron transfer complex than for the separated aqua ions.

Oberhofer, Harald; Blumberger, Jochen [Department of Chemistry, University of Cambridge, Cambridge CB2 1EW (United Kingdom)

2009-08-14T23:59:59.000Z

53

Spin dynamics simulation of electron spin relaxation in Ni{sup 2+}(aq)  

SciTech Connect (OSTI)

The ability to quantitatively predict and analyze the rate of electron spin relaxation of open-shell systems is important for electron paramagnetic resonance and paramagnetic nuclear magnetic resonance spectroscopies. We present a combined molecular dynamics (MD), quantum chemistry (QC), and spin dynamics simulation method for calculating such spin relaxation rates. The method is based on the sampling of a MD trajectory by QC calculations, to produce instantaneous parameters of the spin Hamiltonian used, in turn, to numerically solve the Liouville-von Neumann equation for the time evolution of the spin density matrix. We demonstrate the approach by simulating the relaxation of electron spin in an aqueous solution of Ni{sup 2+} ion. The spin-lattice (T{sub 1}) and spin-spin (T{sub 2}) relaxation rates are extracted directly from the simulations of the time dependence of the longitudinal and transverse magnetization, respectively. Good agreement with the available, indirectly obtained experimental data is obtained by our method.

Rantaharju, Jyrki, E-mail: jjrantaharju@gmail.com; Mare, Ji?, E-mail: jiri.mares@oulu.fi; Vaara, Juha, E-mail: juha.vaara@iki.fi [NMR Research Group, Department of Physics, University of Oulu, P.O. Box 3000, Oulu, FIN-90014 (Finland)

2014-07-07T23:59:59.000Z

54

Dynamical thickening transition in plate coating with concentrated surfactant solutions  

E-Print Network [OSTI]

We present a large range of experimental data concerning the influence of surfactants on the well-known Landau-Levich-Derjaguin experiment where a liquid film is generated by pulling a solid plate out of a bath. The thickness h of the film was measured as a function of the pulling velocity V for different kind of surfactant and at various concentrations. Measuring the thickening factor $\\alpha=h/h_{LLD}$, where hLLD is obtained for a pure liquid, in a wide range of capillary ($Ca=\\eta V/\\gamma$), two regimes of constant thickening can be identified: at small capillary number, $\\alpha$ is large due to a confinement and surface elasticity (or Marangoni) effects and at large Ca, $\\alpha$ is slightly higher than unity, due to surface viscous effects. At intermediate Ca, $\\alpha$ decreases as Ca increases along a "dynamic transition". In the case of non-ionic surfactants, the dynamic transition occurs at a fixed Ca, independently of the surfactant concentration, while for ionic surfactants, the dynamic transition depends on the concentration due to the existence of an electrostatic barrier. The control of physico-chemical parameters allowed us to elucidate the nature of the dynamic transition and to relate it to surface rheology.

Jrme Delacotte; Lorraine Montel; Frdric Restagno; Benot Scheid; Benjamin Dollet; Howard A. Stone; Dominique Langevin; Emmanuelle Rio

2011-06-10T23:59:59.000Z

55

Kinetics and mechanism of bimolecular electron transfer reaction in quinone-amine systems in micellar solution  

SciTech Connect (OSTI)

Photoinduced electron transfer (ET) reactions between anthraquinone derivatives and aromatic amines have been investigated in sodium dodecyl sulphate (SDS) micellar solutions. Significant static quenching of the quinone fluorescence due to high amine concentration in the micellar phase has been observed in steady-state measurements. The bimolecular rate constants for the dynamic quenching in the present systems k{sub q}{sup TR}, as estimated from the time-resolved measurements, have been correlated with the free energy changes {delta}G{sup 0} for the ET reactions. Interestingly it is seen that the k{sub q}{sup TR} vs {delta}G{sup 0} plot displays an inversion behavior with maximum k{sub q}{sup TR} at around 0.7 eV, a trend similar to that predicted in Marcus ET theory. Like the present results, Marcus inversion in the k{sub q}{sup TR} values was also observed earlier in coumarin-amine systems in SDS and TX-100 micellar solutions, with maximum k{sub q}{sup TR} at around the same exergonicity. These results thus suggest that Marcus inversion in bimolecular ET reaction is a general phenomenon in micellar media. Present observations have been rationalized on the basis of the two-dimensional ET (2DET) theory, which seems to be more suitable for micellar ET reactions than the conventional ET theory. For the quinone-amine systems, it is interestingly seen that k{sub q}{sup TR} vs {delta}G{sup 0} plot is somewhat wider in comparison to that of the coumarin-amine systems, even though the maxima in the k{sub q}{sup TR} vs {delta}G{sup 0} plots appear at almost similar exergonicity for both the acceptor-donor systems. These observations have been rationalized on the basis of the differences in the reaction windows along the solvation axis, as envisaged within the framework of the 2DET theory, and arise due to the differences in the locations of the quinones and coumarin dyes in the micellar phase.

Kumbhakar, Manoj; Nath, Sukhendu; Mukherjee, Tulsi; Pal, Haridas [Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2005-02-22T23:59:59.000Z

56

Monitoring attosecond dynamics of coherent electron-nuclear wave packets by molecular high-order-harmonic generation  

SciTech Connect (OSTI)

A pump-probe scheme for preparing and monitoring electron-nuclear motion in a dissociative coherent electron-nuclear wave packet is explored from numerical solutions of a non-Born-Oppenheimer time-dependent Schroedinger equation. A mid-ir intense few-cycle probe pulse is used to generate molecular high-order-harmonic generation (MHOHG) from a coherent superposition of two or more dissociative coherent electronic-nuclear wave packets, prepared by a femtosecond uv pump pulse. Varying the time delay between the intense ir probe pulse and the uv pump pulse by a few hundreds of attoseconds, the MHOHG signal intensity is shown to vary by orders of magnitude, thus showing the high sensitivity to electron-nuclear dynamics in coherent electron-nuclear wave packets. We relate this high sensitivity of MHOHG spectra to opposing electron velocities (fluxes) in the electron wave packets of the recombining (recolliding) ionized electron and of the bound electron in the initial coherent superposition of two electronic states.

Bredtmann, Timm [Laboratoire de Chimie Theorique, Faculte des Sciences, Universite de Sherbrooke, Sherbrooke, Quebec, J1K 2R1 (Canada); Institut fuer Chemie und Biochemie, Freie Universitaet Berlin, Takustrasse 3, D-14195 Berlin (Germany); Chelkowski, Szczepan; Bandrauk, Andre D. [Laboratoire de Chimie Theorique, Faculte des Sciences, Universite de Sherbrooke, Sherbrooke, Quebec, J1K 2R1 (Canada)

2011-08-15T23:59:59.000Z

57

Dynamics of a nanodroplet under a transmission electron microscope  

SciTech Connect (OSTI)

We investigate the cyclical stick-slip motion of water nanodroplets on a hydrophilic substrate viewed with and stimulated by a transmission electron microscope. Using a continuum long wave theory, we show how the electrostatic stress imposed by non-uniform charge distribution causes a pinned convex drop to deform into a toroidal shape, with the shape characterized by the competition between the electrostatic stress and the surface tension of the drop, as well as the charge density distribution which follows a Poisson equation. A horizontal gradient in the charge density creates a lateral driving force, which when sufficiently large, overcomes the pinning induced by surface heterogeneities in the substrate disjoining pressure, causing the drop to slide on the substrate via a cyclical stick-slip motion. Our model predicts step-like dynamics in drop displacement and surface area jumps, qualitatively consistent with experimental observations.

Leong, Fong Yew, E-mail: leongfy@ihpc.a-star.edu.sg [A-STAR Institute of High Performance Computing, 1 Fusionopolis Way, Connexis, Singapore 138632 (Singapore); Mirsaidov, Utkur M. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); Center for BioImaging Sciences, National University of Singapore, Science Drive 4, Singapore 117543 (Singapore); Matsudaira, Paul [Center for BioImaging Sciences, National University of Singapore, Science Drive 4, Singapore 117543 (Singapore); MechanoBiology Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411 (Singapore); Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543 (Singapore); Singapore-MIT Alliance for Research and Technology Center, Science Drive 2, Singapore 117543 (Singapore); Mahadevan, L. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA and Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

2014-01-15T23:59:59.000Z

58

Dynamic structure factor of a stiff polymer in a glassy solution  

E-Print Network [OSTI]

We provide a comprehensive overview of the current theoretical understanding of the dynamic structure factor of stiff polymers in semidilute solution based on the wormlike chain (WLC) model. We extend previous work by computing exact numerical coefficients and an expression for the dynamic mean square displacement (MSD) of a free polymer and compare various common approximations for the hydrodynamic interactions, which need to be treated accurately if one wants to extract quantitative estimates for model parameters from experimental data. A recent controversy about the initial slope of the dynamic structure factor is thereby resolved. To account for the interactions of the polymer with a surrounding (sticky) polymer solution, we analyze an extension of the WLC model, the glassy wormlike chain (GWLC), which predicts near power-law and logarithmic long-time tails in the dynamic structure factor.

J. Glaser; O. Hallatschek; K. Kroy

2008-05-29T23:59:59.000Z

59

Attosecond Control of Electron Dynamics in Carbon Monoxide I. Znakovskaya,1  

E-Print Network [OSTI]

Attosecond Control of Electron Dynamics in Carbon Monoxide I. Znakovskaya,1 P. von den Hoff,2 S by manipulating the laser frequency, phase and polarization in closed loop experiments [1]. Control- faces in the observed control? We describe experiments, where control of electron dynamics in carbon

Kling, Matthias

60

Control of ultrafast electron dynamics with shaped femtosecond laser pulses: from atoms to solids  

E-Print Network [OSTI]

Control of ultrafast electron dynamics with shaped femtosecond laser pulses: from atoms to solids;1. Introduction In coherent control shaped femtosecond laser pulses are used as a tool to steer the ultrafast focus on advanced control of ultrafast electron dynamics with shaped femtosecond laser pulses

Peinke, Joachim

Note: This page contains sample records for the topic "dynamic electron solutions" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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61

Dynamics of excess electrons in atomic and molecular clusters  

E-Print Network [OSTI]

Time-Resolved Dynamics in Acetonitrile Cluster Anions (CH 3Time-resolved dynamics in acetonitrile clusters anions (CH 3resolved dynamics in acetonitrile clusters anions (CH 3 CN)

Young, Ryan Michael

2011-01-01T23:59:59.000Z

62

Ion Association in AlCl3 Aqueous Solutions from Constrained First-Principles Molecular Dynamics  

SciTech Connect (OSTI)

Ab initio molecular dynamics was used to investigate the ion pairing behavior between Cl- and the Al3+ ion in an aqueous AlCl3 solution containing 63 water molecules. A series of constrained simulations was carried out at 300 K for up to 16 ps each, by fixing the inter-nuclear separation (rAl-Cl) between the Al3+ ion and one of the Cl- ions. The calculated potential of mean force of the Al3+-Cl- ion pair shows a pronounced minimum at rAl-Cl = 2.3 corresponding to a contact ion pair (CIP). Two local minima assigned to solvent separated ion pairs (SSIP) are identified at rAl-Cl= 4.4 and 6.0 . The positions of the free energy minima coincide with the hydration shell intervals of the Al3+ cation suggesting that the Cl- ion is inclined to reside in regions of low concentration of waters, i.e. between the 1st and 2nd shells of Al3+ and between the 2nd shell and bulk. A detailed analysis of solvent structure around the Al3+ and Cl- ions as a function of rAl-Cl is presented. The results are compared to structure data from X-ray measurements and unconstrained AIMD simulations of single ions Al3+ and Cl- and AlCl3 solutions. The dipole moment of the water molecules inside the 1st and 2nd hydration shells of Al3+ and in the bulk region and those of the Clion were calculated as a function of rAl-Cl. Major changes in the electronic structure of the system result from the removal of Cl- from the 1st hydration shell of the Al3+ cation. Finally, two unconstrained AIMD simulations of aqueous AlCl3 solutions corresponding to CIP and SSIP configurations were performed (17 ps, 300 K). Only minor structural changes are observed in these systems, confirming their stability.

Cauet, Emilie L.; Bogatko, Stuart A.; Bylaska, Eric J.; Weare, John H.

2012-10-15T23:59:59.000Z

63

Sub-100-ps structural dynamics of horse heart myoglobin probed by time-resolved X-ray solution scattering  

E-Print Network [OSTI]

Sub-100-ps structural dynamics of horse heart myoglobin probed by time-resolved X-ray solution-slicing Structural dynamics Myoglobin a b s t r a c t Here we report sub-100-ps structural dynamics of horse heart to the measurement and subsequent deconvolution, we investigate the protein structural dynamics that occur faster

Ihee, Hyotcherl

64

Spectroscopy, polarization and nonadiabatic dynamics of electronically excited Ba(Ar)n clusters: Theory and experiment  

E-Print Network [OSTI]

Spectroscopy, polarization and nonadiabatic dynamics of electronically excited Ba(Ar)n clusters, France Received 13 September 1995; accepted 17 November 1995 Molecular Dynamics simulations using, a comprehensive picture of the excited state dynamics is given. It is found that upon excitation, energy

Krylov, Anna I.

65

Optical pumpterahertz probe spectroscopy of dyes in solutions: Probing the dynamics of liquid solvent or solid precipitate?  

E-Print Network [OSTI]

dynamics simulations to investigate ultrafast dynamics following electronic excitation of Coumarin 153 and dynamics, preferably at a molecular level of reso- lution. In particular, solvent relaxation following body of time-resolved spectro- scopic studies, as well as molecular dynamics MD simula- tions have been

Ku?el, Petr

66

Dynamics and solutions to some control problems for water-tank systems  

E-Print Network [OSTI]

1 Dynamics and solutions to some control problems for water-tank systems Nicolas Petit , Pierre translations and rotations. The fluid motion is described by linearized wave equations under shallow water describe the lack of approximate controllability. The first contribution of the paper consists of models

67

Water Dynamics in Salt Solutions Studied with Ultrafast Two-Dimensional Infrared (2D IR)  

E-Print Network [OSTI]

Water Dynamics in Salt Solutions Studied with Ultrafast Two-Dimensional Infrared (2D IR RECEIVED ON FEBRUARY 3, 2009 C O N S P E C T U S Water is ubiquitous in nature, but it exists as pure water infrequently. From the ocean to biology, water molecules interact with a wide variety of dissolved species

Fayer, Michael D.

68

Variational Results and Solutions in Gauge Gravity and a Bifurcation Analysis of Black Hole Orbital Dynamics  

E-Print Network [OSTI]

An analysis of all known spherically symmetric solutions to the field equations originating from the Riemann tensor quadratic curvature Lagrangian is presented. A new exact solution is found for the field equation originating from the "energy-momentum" equation of the gauge gravity theory. Imposing equivalence between the Palatini and standard variational field equations yields an algebraic condition that restricts the number spacetime solutions to gauge gravity. An analysis of a new spherically symmetric solution to the conformal gravity field equations is also presented. Point particle orbital dynamics in both the Schwarzschild and Reissner-Nordstrom black hole spacetimes are analyzed as 2-d conservative bifurcation phenomena. The Schwarzschild dynamics exhibit both saddle-center and transcritical bifurcation points and a calculation of periastron precession is presented that incorporates a phase-plane analysis of the relativistic equations of motion. Level curves of constant energy are illustrated for both timelike and null geodesics and a phase-plane analysis of dynamical invariance between the proper and coordinate time reference frames is discussed. The Reissner-Nordstrom dynamics exhibit saddle-center, transcritical, pseudo-transcritical, and additional bifurcations that combine all three previous bifurcations in various combinations. Periastron precession in the Reissner-Nordstrom spacetime is analyzed using the phase-plane and bifurcation techniques and extended to include a bifurcation point of the dynamics. A numerical solution at these parameter values illustrates that such orbits typically yield a much larger precession value compared to the standard value for timelike, precession. The acausal geodesics considered by Brigman are also discussed and their precession value is calculated.

Bruce Herold Dean

2013-12-29T23:59:59.000Z

69

Electron beam dynamics for the ISIS bremsstrahlung beam generation system  

E-Print Network [OSTI]

An electron beam transport system was designed for use in the Bremsstrahlung Beam Generation System of the Integrated Stand-off Inspection System (ISIS). The purpose of this electron transport system was to provide for ...

Block, Robert E. (Robert Edward)

2011-01-01T23:59:59.000Z

70

Dynamics of a beam of hot electrons propagating through a plasma in the presence of nonthermal electrons  

SciTech Connect (OSTI)

The dynamics of a beam of hot electrons traveling through a cold plasma and the generation of Langmuir waves are investigated in the presence of a nonthermal tail of electrons in the background distribution function. Using quasilinear simulations, it is shown that in the presence of the nonthermal electrons, the relaxation of the beam distribution function in velocity space is retarded and the Langmuir waves are strongly damped at low velocities. The average velocity of beam propagation is almost constant but its magnitude is larger in the presence of nonthermal electrons than their absence. It is found that the self-similarity of the system is preserved in the presence of nonthermal electrons. The effects of nonthermal electrons on the evolution of gas-dynamical parameters of the beam, including the height of plateau in the beam distribution function, its upper and lower velocity boundaries, and beam velocity width, are also studied. It is found that initially the values of the upper and lower velocity boundaries are almost unaltered, but at large times the lower (upper) boundary velocity is larger (smaller) in the presence of nonthermal electrons than without the nonthermal electrons.

Khalilpour, H.; Moslehi-Fard, M. [Faculty of Physics, Tabriz University, 51664 Tabriz (Iran, Islamic Republic of); Foroutan, G. [Department of Physics, Faculty of Science, Sahand University of Technology, 51335-1996 Tabriz (Iran, Islamic Republic of); School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia); Li, B.; Robinson, P. A. [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia)

2009-07-15T23:59:59.000Z

71

Simultaneous investigation of ultrafast structural dynamics and transient electric field by sub-picosecond electron pulses  

SciTech Connect (OSTI)

The ultrafast structure dynamics and surface transient electric field, which are concurrently induced by laser excited electrons of an aluminum nanofilm, have been investigated simultaneously by the same transmission electron diffraction patterns. These two processes are found to be significantly different and distinguishable by tracing the time dependent changes of electron diffraction and deflection angles, respectively. This study also provides a practical means to evaluate simultaneously the effect of transient electric field during the study of structural dynamics under low pump fluence by transmission ultrafast electron diffraction.

Li, Run-Ze; Zhu, Pengfei; Chen, Long; Chen, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn; Sheng, Zheng-Ming; Zhang, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Cao, Jianming [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Physics Department and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

2014-05-14T23:59:59.000Z

72

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 19, NO. 2, MARCH 2004 491 A Complete Solution to the Harmonic  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 19, NO. 2, MARCH 2004 491 A Complete Solution be found. In particular, it is shown that there are new solutions that have not been previously reported in an inverter are not a concern (i.e., switching on the order of a few kHz is acceptable), then the sine

Tolbert, Leon M.

73

PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal  

E-Print Network [OSTI]

PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal Patrick L-dynamics simulations of the single shock Hugoniot are reported for a crystalline polyethylene (PE) model. The e. INTRODUCTION The material response of polyethylene (PE) to shock and its behavior in the warm dense matter (WDM

74

Substrate-limited electron dynamics in graphene S. Fratini1,2 and F. Guinea2  

E-Print Network [OSTI]

Substrate-limited electron dynamics in graphene S. Fratini1,2 and F. Guinea2 1Institut Néel dynamics in graphene. We find that the quasiparticle spectrum acquires a finite broadening due to the long-range interaction with the polar modes at the interface between graphene and the substrate. This mechanism results

Boyer, Edmond

75

Hybrid approach for including electronic and nuclear quantum effects in molecular dynamics simulations of hydrogen transfer  

E-Print Network [OSTI]

Hybrid approach for including electronic and nuclear quantum effects in molecular dynamics January 2001 A hybrid approach for simulating proton and hydride transfer reactions in enzymes coefficient and to investigate the real-time dynamics of reactive trajectories. This hybrid approach includes

Hammes-Schiffer, Sharon

76

Non-adiabatic molecular dynamics simulation of ultrafast solar cell electron transfer  

E-Print Network [OSTI]

confinement devices [1­5]. Solar cells of the Graetzel type [6,7] are based on dye sensitized nanocrystalline in solar cells, photocatalysis and photoelectrolysis. The electronic structure of the dye cell; Ultrafast electron transfer; Non-adiabatic molecular dynamics simulation; Dye sensitized titanium

77

Feasibility of measuring surface electron spin dynamics by inelastic scattering of metastable helium atoms  

E-Print Network [OSTI]

helium atoms M. El-Batanouny, G. Murthy, and C. R. Willis Department of Physics, Boston University atoms (He*) from surfaces of magnetic insulators to study the dynamical properties of surface electron a metastable He atom and the surface electron spins are determined by a configuration interaction calculation

Kais, Sabre

78

Numerical solutions of the aerosol general dynamic equation for nuclear reactor safety studies  

SciTech Connect (OSTI)

Methods and approximations inherent in modeling of aerosol dynamics and evolution for nuclear reactor source term estimation have been investigated. Several aerosol evolution problems are considered to assess numerical methods of solving the aerosol dynamic equation. A new condensational growth model is constructed by generalizing Mason's formula to arbitrary particle sizes, and arbitrary accommodation of the condensing vapor and background gas at particle surface. Analytical solution is developed for the aerosol growth equation employing the new condensation model. The space-dependent aerosol dynamic equation is solved to assess implications of spatial homogenization of aerosol distributions. The results of our findings are as follows. The sectional method solving the aerosol dynamic equation is quite efficient in modeling of coagulation problems, but should be improved for simulation of strong condensation problems. The J-space transform method is accurate in modeling of condensation problems, but is very slow. For the situation considered, the new condensation model predicts slower aerosol growth than the corresponding isothermal model as well as Mason's model, the effect of partial accommodation is considerable on the particle evolution, and the effect of the energy accommodation coefficient is more pronounced than that of the mass accommodation coefficient. For the initial conditions considered, the space-dependent aerosol dynamics leads to results that are substantially different from those based on the spatially homogeneous aerosol dynamic equation.

Park, J.W.

1988-01-01T23:59:59.000Z

79

Femtosecond soft x-ray spectroscopy of solvated transition metal complexes: Deciphering the interplay of electronic and structural dynamics  

SciTech Connect (OSTI)

We present the first implementation of femtosecond soft X-ray spectroscopy as an ultrafast direct probe of the excited-state valence orbitals in solution-phase molecules. This method is applied to photoinduced spin crossover of [Fe(tren(py)3)]2+, where the ultrafast spinstate conversion of the metal ion, initiated by metal-to-ligand charge-transfer excitation, is directly measured using the intrinsic spin-state selectivity of the soft X-ray L-edge transitions. Our results provide important experimental data concerning the mechanism of ultrafast spin-state conversion and subsequent electronic and structural dynamics, highlighting the potential of this technique to study ultrafast phenomena in the solution phase.

Huse, Nils; Cho, Hana; Hong, Kiryong; Jamula, Lindsey; de Groot, Frank M. F.; Kim, Tae Kyu; McCusker, James K.; Schoenlein, Robert W.

2011-03-09T23:59:59.000Z

80

Laser Assisted Nanomanufacturing with Solution Processed Nanoparticles for Low-cost Electronics and Photovoltaics  

E-Print Network [OSTI]

Electronics and Photovoltaics by Heng Pan A dissertationcost Electronics and Photovoltaics Copyright 2009 By HengLow-cost Electronics and Photovoltaics by Heng Pan Doctor of

Pan, Heng

2009-01-01T23:59:59.000Z

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


81

Wafer-scale solution-derived molecular gate dielectrics for low-voltage graphene electronics  

SciTech Connect (OSTI)

Graphene field-effect transistors are integrated with solution-processed multilayer hybrid organic-inorganic self-assembled nanodielectrics (SANDs). The resulting devices exhibit low-operating voltage (2?V), negligible hysteresis, current saturation with intrinsic gain >1.0 in vacuum (pressure?electronics.

Sangwan, Vinod K.; Jariwala, Deep; McMorrow, Julian J.; He, Jianting; Lauhon, Lincoln J. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Everaerts, Ken [Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States); Grayson, Matthew [Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208 (United States); Marks, Tobin J., E-mail: t-marks@northwestern.edu, E-mail: m-hersam@northwestern.edu; Hersam, Mark C., E-mail: t-marks@northwestern.edu, E-mail: m-hersam@northwestern.edu [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)

2014-02-24T23:59:59.000Z

82

Ultrafast control of strong-field electron dynamics in solids  

E-Print Network [OSTI]

We review theoretical foundations and some recent progress related to the quest of controlling the motion of charge carriers with intense laser pulses and optical waveforms. The tools and techniques of attosecond science enable detailed investigations of a relatively unexplored regime of nondestructive strong-field effects. Such extremely nonlinear effects may be utilized to steer electron motion with precisely controlled optical fields and switch electric currents at a rate that is far beyond the capabilities of conventional electronics.

Vladislav S. Yakovlev; Stanislav Yu. Kruchinin; Tim Paasch-Colberg; Mark I. Stockman; Ferenc Krausz

2015-02-17T23:59:59.000Z

83

Picosecond spectroscopy and solvation clusters. The dynamics of localizing electrons in polar fluids  

SciTech Connect (OSTI)

New spectroscopic evidence concerning the dynamics of electron-induced solvation clusters in polar liquids is presented and integrated with previous picosecond data, in order to outline the roles molecular dynamics and structure can play both in initiating electron localization at subpicosecond times and in governing the solvation dynamics to form e/sup -//sub s/ in the picosecond domain. Particulr emphasis is placed on the picosecond time-resolved absorption spectroscopy of electrons in a wide range of alcohols and alcohol-alkane systems at 300/sup 0/K as a framework for the cluster model of electron solvation. While the configurationally relaxed final quantum state of e/sup -//sub s/ appears identical for e/sup -//sub s/ generated by different techniques, it is possible that the time evolution of the solvation cluster and the dynamics of electron populations between localized and continuum states could be influenced by the initial state of the system. Selected examples are discussed for alcohols, amines, and water, and comparisons are made for picosecond observations from different visible and IR spectroscopic techniques, NMR, and complementary nanosecond electron mobility data to demonstrate the overall consistency of a model in which only the dynamical, microscopic properties of the liquid determine these solvation events.

Kenney-Wallace, G.A. (Univ. of Toronto, Ontario); Jonah, C.D.

1982-07-08T23:59:59.000Z

84

Rapid imaging of mycoplasma in solution using Atmospheric Scanning Electron Microscopy (ASEM)  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer Mycoplasma mobile was observed in buffer with the Atmospheric Scanning Electron Microscope. Black-Right-Pointing-Pointer Characteristic protein localizations were visualized using immuno-labeling. Black-Right-Pointing-Pointer M. mobile attached to sialic acid on the SiN film surface within minutes. Black-Right-Pointing-Pointer Cells were observed at low concentrations. Black-Right-Pointing-Pointer ASEM should promote study and early-stage diagnosis of mycoplasma. -- Abstract: Mycoplasma is a genus of bacterial pathogen that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. In current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2-3 {mu}m-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.

Sato, Chikara, E-mail: ti-sato@aist.go.jp [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan)] [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan); Manaka, Sachie [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan)] [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan); Nakane, Daisuke [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan)] [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan); Nishiyama, Hidetoshi; Suga, Mitsuo [Advanced Technology Division, JEOL Ltd., Akishima, Tokyo 196-8558 (Japan)] [Advanced Technology Division, JEOL Ltd., Akishima, Tokyo 196-8558 (Japan); Nishizaka, Takayuki [Department of Physics, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588 (Japan)] [Department of Physics, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588 (Japan); Miyata, Makoto [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan)] [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan); Maruyama, Yuusuke [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan)] [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan)

2012-01-27T23:59:59.000Z

85

A time-dependent momentum-space density functional theoretical approach for electron transport dynamics in molecular devices  

E-Print Network [OSTI]

for electron transport dynamics in molecular devices Zhongyuan Zhou(a) and Shih-I Chu Department of Chemistry and structures PACS 85.65.+h ­ Molecular electronic devices PACS 71.15.Pd ­ Molecular dynamics calculations (Carr) approach in momentum (P) space for the study of electron transport in molecular devices under arbitrary

Chu, Shih-I

86

Transient Dynamics in Molecular Junctions: Coherent Bichromophoric Molecular Electron Pumps  

E-Print Network [OSTI]

The possibility of using single molecule junctions as electron pumps for energy conversion and storage is considered. It is argued that the small dimensions of these systems enable to make use of unique intra-molecular quantum coherences in order to pump electrons between two leads and to overcome relaxation processes which tend to suppress the pumping efficiency. In particular, we demonstrate that a selective transient excitation of one chromophore in a bi-chromophoric donor-bridge-acceptor molecular junction model yields currents which transfer charge (electron and holes) unevenly to the two leads in the absence of a bias potential. The utility of this mechanism for charge pumping in steady state conditions is proposed.

Roie Volkovich; Uri Peskin

2010-12-01T23:59:59.000Z

87

Using femtosecond electron pulses as an imaging tool, we can probe ultrafast dynamics by taking snapshots at different time delays. By using femtosecond electron diffraction (FED),  

E-Print Network [OSTI]

Abstract Using femtosecond electron pulses as an imaging tool, we can probe ultrafast dynamics correlation. Additionally, ultrafast electron shadow imaging (UESI) can explore the dynamics of laser induced System The femtosecond "camera" mentioned above is comprised of an amplified femtosecond pulsed laser

Weston, Ken

88

Attosecond intramolecular electron dynamics A. Becker1,a  

E-Print Network [OSTI]

), over one half cycle of the oscillation of the laser electric field the ionization rate of the hydrogen of an electron from an atom or molecule is presumably one of the simplest but most central processes in physics field. In tunnel ionization, the combined potential of the Coulomb attraction of the atomic or molecular

Becker, Andreas

89

Exact solution for quantum dynamics of a periodically-driven two-level-system  

E-Print Network [OSTI]

We present a family of exact analytic solutions for non-linear quantum dynamics of a two-level system (TLS) subject to a periodic-in-time external field. In constructing the exactly solvable models, we use a "reverse engineering" approach where the form of external perturbation is chosen to preserve an integrability constraint, which yields a single non-linear differential equation for the ac-field. A solution to this equation is expressed in terms of Jacobi elliptic functions with three independent parameters that allows one to choose the frequency, average value, and amplitude of the time-dependent field at will. This form of the ac-drive is especially relevant to the problem of dynamics of TLS charge defects that cause dielectric losses in superconducting qubits. We apply our exact results to analyze non-linear dielectric response of such TLSs and show that the position of the resonance peak in the spectrum of the relevant correlation function is determined by the quantum-mechanical phase accumulated by the TLS wave-function over a time evolution cycle. It is shown that in the non-linear regime, this resonance frequency may be shifted strongly from the value predicted by the canonical TLS model. We also analyze the "spin" survival probability in the regime of strong external drive and recover a coherent destruction of tunneling phenomenon within our family of exact solutions, which manifests itself as a strong suppression of "spin-flip" processes and suggests that such non-linear dynamics in LC-resonators may lead to lower losses.

Anirban Gangopadhyay; Maxim Dzero; Victor Galitski

2010-05-05T23:59:59.000Z

90

A unified electrostatic and cavitation model for first-principles molecular dynamics in solution  

E-Print Network [OSTI]

The electrostatic continuum solvent model developed by Fattebert and Gygi is combined with a first-principles formulation of the cavitation energy based on a natural quantum-mechanical definition for the surface of a solute. Despite its simplicity, the cavitation contribution calculated by this approach is found to be in remarkable agreement with that obtained by more complex algorithms relying on a large set of parameters. Our model allows for very efficient Car-Parrinello simulations of finite or extended systems in solution, and demonstrates a level of accuracy as good as that of established quantum-chemistry continuum solvent methods. We apply this approach to the study of tetracyanoethylene dimers in dichloromethane, providing valuable structural and dynamical insights on the dimerization phenomenon.

Damian A. Scherlis; Jean-Luc Fattebert; Francois Gygi; Matteo Cococcioni; Nicola Marzari

2005-10-06T23:59:59.000Z

91

Local Dielectric Environment of B-DNA in Solution: Results from a 14 ns Molecular Dynamics Trajectory  

E-Print Network [OSTI]

Local Dielectric Environment of B-DNA in Solution: Results from a 14 ns Molecular Dynamics trajectory of B-DNA developed in a medium of explicit waters and sodium counterions with particle mesh Ewald around DNA are providing a reasonably accurate account of the local solution environment of a complicated

Jayaram, Bhyravabotla

92

Molecular Simulations of Aqueous Electrolyte Solubility: 1. The Expanded-Ensemble Osmotic Molecular Dynamics Method for the Solution Phase  

E-Print Network [OSTI]

+, and Cl-); undissociated molecular units (HgCl2) are the predominant solution solute species.1 such as mercury(II) chloride (HgCl2), only a small fraction of the atoms dissociate into free ions (HgCl+, Hg2 Dynamics Method for the Solution Phase Martin Li´sal,*,, William R. Smith,§ and Jiri´ Kolafa| E. Ha

Lisal, Martin

93

In Situ, Real-Time Characterization of Silicide Nanostructure Coarsening Dynamics by Photo-Electron Emission Microscopy.  

E-Print Network [OSTI]

??Photo-electron emission microscopy (PEEM) was used to observe the growth and coarsening dynamics of transition metal (TM) silicide and rare earth (RE) silicide nanostructures on (more)

Zeman, Matthew Casimir

2007-01-01T23:59:59.000Z

94

The First Events in Photosynthesis: Electronic Coupling and Energy Transfer Dynamics in the Photosynthetic Reaction Center from Rhodobacter sphaeroides  

E-Print Network [OSTI]

The First Events in Photosynthesis: Electronic Coupling and Energy Transfer Dynamics in photosynthesis. The reaction center contains six chlorophyll-like pigments arranged with approximate C2 symmetry

Scherer, Norbert F.

95

Semiclassical (SC) Description of Electronically Non-AdiabaticDynamics via the Initial Value Representation (IVR)  

SciTech Connect (OSTI)

The initial value representation (IVR) of semiclassical (SC) theory is used in conjunction with the Meyer-Miller/Stock-Thoss description of electronic degrees of freedom in order to treat electronically non-adiabatic processes. It is emphasized that the classical equations of motion for the nuclear and electronic degrees of freedom that emerge in this description are precisely the Ehrenfest equations of motion (the force on the nuclei is the force averaged over the electronic wavefunction), but that the trajectories given by these equations of motion do not have the usual shortcomings of the traditional Ehrenfest model when they are used within the SC-IVR framework. For example, in the traditional Ehrenfest model (a mixed quantum-classical approach) the nuclear motion emerges from a non-adiabatic encounter on an average potential energy surface (a weighted average according to the population in the various electronic states), while the SC-IVR describes the correct correlation between electronic and nuclear dynamics, i.e., the nuclear motion is on one potential energy surface or the other depending on the electronic state. Calculations using forward-backward versions of SC-IVR theory (FB-IVR) are presented to illustrate this behavior. An even more approximate version of the SC-IVR, the linearized approximation (LSC-IVR), is slightly better than the traditional Ehrenfest model, but since it cannot describe quantum coherence effects, the LSC-IVR is also not able to describe the correct correlation between nuclear and electronic dynamics.

Ananth, V.; Venkataraman, C.; Miller, W.H.

2007-06-22T23:59:59.000Z

96

Large dynamic range diagnostics for high current electron LINACs  

SciTech Connect (OSTI)

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

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

2013-11-07T23:59:59.000Z

97

Electron transfer and capture dynamics in ZnSe quantum wells grown on GaAs  

SciTech Connect (OSTI)

We investigate the transfer and capture dynamics of electrons in phase coherent photorefractive ZnSe quantum wells grown on GaAs using degenerate three-beam four-wave-mixing. The measurements reveal electron capture times by the quantum well in the order of several tens of picoseconds and a transit time of approximately 5 picoseconds from the GaAs substrate through the ZnMgSe barrier.

Dongol, A.; Wagner, H. P. [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States)

2013-12-04T23:59:59.000Z

98

Entangled valence electron-hole dynamics revealed by stimulated attosecond x-ray Raman scattering  

SciTech Connect (OSTI)

We show that broadband x-ray pulses can create wavepackets of valence electrons and holes localized in the vicinity of a selected atom (nitrogen, oxygen or sulfur in cysteine) by resonant stimulated Raman scattering. The subsequent dynamics reveals highly correlated motions of entangled electrons and hole quasiparticles. This information goes beyond the time-dependent total charge density derived from x-ray diffraction.

Healion, Daniel; Zhang, Yu; Biggs, Jason D.; Govind, Niranjan; Mukamel, Shaul

2012-09-06T23:59:59.000Z

99

2012 ELECTRONIC SPECTROSCOPY & DYNAMICS GORDON RESEARCH CONFERENCE, JULY 22-27, 2012  

SciTech Connect (OSTI)

Topics covered in this GRC include high-resolution spectroscopy, coherent electronic energy transport in biology, excited state theory and dynamics, excitonics, electronic spectroscopy of cold and ultracold molecules, and the spectroscopy of nanostructures. Several sessions will highlight innovative techniques such as time-resolved x-ray spectroscopy, frequency combs, and liquid microjet photoelectron spectroscopy that have forged stimulating new connections between gas-phase and condensed-phase work.

Kohler, Bern

2012-07-27T23:59:59.000Z

100

Dynamics, Structure, and Emission of Electron-Positron Jets  

E-Print Network [OSTI]

The theory of gamma-ray emission from e$^{\\pm}$ jets and the implications for jet formation, dynamics and structure are reviewed. In particular, possible carriers of the jet's thrust on small scales, the transition from electromagnetic to particle dominance in Poynting flux jets, formation of pair cascades, synchrotron emission by cascading pairs, and formation of shocks due to unsteadiness in the jet parameters are considered, with emphasis on the observational consequences. Some recent progress in modeling transient emission from blazars is also briefly discussed.

A. Levinson

1997-08-10T23:59:59.000Z

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


101

Dynamics of soft Nanomaterials captured by transmission electron microscopy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed NewcatalystNeutron scattering characterizes dynamics in polymer family Agatha

102

Dynamic Phase Shifts in Nanoscale Distance Measurements by Double Electron  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesDataTranslocationDiurnalCommitteeDurableElectron Resonance

103

Electronic and structural dynamics in transition metal complexes - recent  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4: Networking for the‹Electronic Structure of Cobalt

104

Analytical solutions for energy spectra of electrons accelerated by nonrelativistic shock-waves in shell type supernova remnants  

E-Print Network [OSTI]

%context {Recent observations of hard X-rays and very high energy gamma-rays from a number of young shell type supernova remnants indicate the importance of detailed quantitative studies of energy spectra of relativistic electrons formed via diffusive shock acceleration accompanied by intense nonthermal emission through synchrotron radiation and inverse Compton scattering.} %aim {The aim of this work was derivation of exact asymptotic solutions of the kinetic equation which describes the energy distribution of shock-accelerated electrons for an arbitrary energy-dependence of the diffusion coefficient.} %method {The asymptotic solutions at low and very high energy domains coupled with numerical calculations in the intermediate energy range allow analytical presentations of energy spectra of electrons for the entire energy region.} %results {Under the assumption that the energy losses of electrons are dominated by synchrotron cooling, we derived the exact asymptotic spectra of electrons without any restriction on the diffusion coefficient. We also obtained simple analytical approximations which describe, with accuracy better than ten percent, the energy spectra of nonthermal emission of shock-accelerated electrons due to the synchrotron radiation and inverse Compton scattering.} %conclusions {The results can be applied for interpretation of X-ray and gamma-ray observations of shell type supernova remnants, as well as other nonthermal high energy source populations like microquasars and large scale synchrotron jets of active galactic nuclei.

V. N. Zirakashvili; F. Aharonian

2007-10-26T23:59:59.000Z

105

Photoinduced electron transfer processes in homogeneous and microheterogeneous solutions. Progress report, April 16, 1992--December 1, 1992  

SciTech Connect (OSTI)

The studies have focused on rapid, efficient bond-fragmentation reactions initiated through photoinduced electron transfer. Electron transfer induced fragmentation of a number of donors have been examined, especially 1,2 diamines and related compounds. Two of the amines fragment with rate constants of 3 {times} 10{sup 8} to 2 {times} 10{sup 9} M{sup {minus}1}sec{sup {minus}1}. A series of amino-substituted pinacols and related compounds have also been examined; they undergo similar but slower fragmentation processes when converted to their cation radicals by photoinduced electron transfer. The studies with linked and polymeric electron donor- electron acceptor coupled molecules have also progressed. Several polymers containing diamine repeat units and anthraquinone or nitroaromatic acceptors have also been prepared that can be photoactivated by visible irradiation; they fragment efficiently in solution and photodegrade even in the solid state. The studies of singlet oxygen initiated fragmentation reactions of diamines, amino alcohols, and aminoketones have nearly been completed. Attention have been turned to fragmentable electron acceptors such as p- cyanobenzyl bromide; irradiation of electron donors such as methyl- or methoxy-naphthalenes can initiate efficient fragmentation of the electron deficient bromide.

Whitten, D.G.

1992-12-01T23:59:59.000Z

106

Optically detected coherent spin dynamics of a single electron in a quantum dot  

E-Print Network [OSTI]

dynamics provide a sensitive probe of the local nuclear spin environment. The magneto-optical Kerr effect the sample, analogous to the Faraday effect for transmitted light. For a probe laser energy E, the KR angle,y are momentum operators. For a single conduction band energy level in a QD containing a spin-up electron

Loss, Daniel

107

Dynamic Characterization of Graphene Growth and Etching by Oxygen on Ru(0001) by Photoemission Electron Microscopy  

E-Print Network [OSTI]

Dynamic Characterization of Graphene Growth and Etching by Oxygen on Ru(0001) by Photoemission of graphene on Ru(0001) was investigated by photoemission electron microscopy (PEEM) and scanning tunneling, we show that graphene overlayers with sizes ranging from nanometers to sub-millimeters have been

Bao, Xinhe

108

E-Print Network 3.0 - aqueous solution electron Sample Search...  

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

fluid... was able to distinguish between the control solution and the ... Source: Johnson, Mark - Biomedical Engineering Department, Northwestern University Collection:...

109

Complex-Dynamical Solution to the Many-Body Interaction Problem and Its Applications in Fundamental Physics  

E-Print Network [OSTI]

We review the recently proposed unreduced, complex-dynamical solution to the many-body problem with arbitrary interaction and its application to the unified solution of fundamental problems, including dynamic foundations of causally complete quantum mechanics, relativity, particle properties and cosmology. We first analyse the universal properties of this many-body problem solution without any perturbative reduction and show that the emerging new quality of fundamental dynamic multivaluedness (or redundance) of the resulting system configuration leads to the natural and universal concept of dynamic complexity, chaoticity and fractality of any real system behaviour. We then consider unified features of this complex dynamics. Applications of that universal description to systems at various complexity levels have been performed and in this paper we review those at the lowest, fundamental complexity levels leading to causal understanding of the unified origin of quantum mechanics, relativity (special and general), elementary particles, their intrinsic properties and interactions. One reveals, in particular, the complex-dynamic origin of inertial and gravitational (relativistic) mass without introduction of any additional particle species, fields or dimensions. Other practically important consequences and problem solutions in fundamental physics and cosmology are summarised, confirming the efficiency of that unified picture.

Andrei P. Kirilyuk

2014-02-06T23:59:59.000Z

110

Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report  

SciTech Connect (OSTI)

This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (s) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOEs research mission. This workshop built on previous workshops and included three breakout sessions identifying scientific challenges in biology, biogeochemistry, catalysis, and materials science frontier areas of fundamental science that underpin energy and environmental science that would significantly benefit from ultrafast transmission electron microscopy (UTEM). In addition, the current status of time-resolved electron microscopy was examined, and the technologies that will enable future advances in spatio-temporal resolution were identified in a fourth breakout session.

Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

2012-07-25T23:59:59.000Z

111

Backscattering and absorption coefficients for electrons: Solutions of invariant embedding transport equations using a method of convergence  

SciTech Connect (OSTI)

The backscattering coefficient is a magnitude whose measurement is fundamental for the characterization of materials with techniques that make use of particle beams and particularly when performing microanalysis. In this work, we report the results of an analytic method to calculate the backscattering and absorption coefficients of electrons in similar conditions to those of electron probe microanalysis. Starting on a five level states ladder model in 3D, we deduced a set of integro-differential coupled equations of the coefficients with a method know as invariant embedding. By means of a procedure proposed by authors, called method of convergence, two types of approximate solutions for the set of equations, namely complete and simple solutions, can be obtained. Although the simple solutions were initially proposed as auxiliary forms to solve higher rank equations, they turned out to be also useful for the estimation of the aforementioned coefficients. In previous reports, we have presented results obtained with the complete solutions. In this paper, we present results obtained with the simple solutions of the coefficients, which exhibit a good degree of fit with the experimental data. Both the model and the calculation method presented here can be generalized to other techniques that make use of different sorts of particle beams.

Figueroa, C.; Brizuela, H.; Heluani, S. P. [Laboratorio de Fsica del Slido, Dpto. de Fsica, Facultad de Ciencias Exactas y Tecnologa, Universidad Nacional de Tucumn (Argentina)

2014-05-21T23:59:59.000Z

112

The Reactivity and Structural Dynamics of Supported Metal Nanoclusters Using Electron Microscopy, in situ X-Ray Spectroscopy, Electronic Structure Theories, and Molecular Dynamics Simulations.  

SciTech Connect (OSTI)

The distinguishing feature of our collaborative program of study is the focus it brings to emergent phenomena originating from the unique structural/electronic environments found in nanoscale materials. We exploit and develop frontier methods of atomic-scale materials characterization based on electron microscopy (Yang) and synchrotron X-ray absorption spectroscopy (Frenkel) that are in turn coupled innately with advanced first principles theory and methods of computational modeling (Johnson). In the past year we have made significant experimental advances that have led to important new understandings of the structural dynamics of what are unquestionably the most important classes of heterogeneous catalyststhe materials used to both produce and mitigate the consequences of the use of liquid hydrocarbon fuels.

Judith C. Yang; Ralph G. Nuzzo, Duane Johnson, Anatoly Frenkel

2008-07-01T23:59:59.000Z

113

A Comparison of Electron-Transfer Dynamics inIonic Liquids and Neutral Solvents  

SciTech Connect (OSTI)

The effect of ionic liquids on photoinduced electron-transfer reactions in a donor-bridge-acceptor system is examined for two ionic liquid solvents, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide and tributylmethylammonium bis(trifluoromethylsulfonyl)amide. The results are compared with those for the same system in methanol and acetonitrile solution. Electron-transfer rates were measured using time-resolved fluorescence quenching for the donor-bridge-acceptor system comprising a 1-N,1-N-dimethylbenzene-1,4-diamine donor, a proline bridge, and a coumarin 343 acceptor. The photoinduced electron-transfer processes are in the inverted regime (-{Delta}G > {lambda}) in all four solvents, with driving forces of -1.6 to -1.9 eV and estimated reorganization energies of about 1.0 eV. The observed electron-transfer kinetics have broadly distributed rates that are generally slower in the ionic liquids compared to the neutral solvents, which also have narrower rate distributions. To describe the broad distributions of electron-transfer kinetics, we use two different models: a distribution of exponential lifetimes and a discrete sum of exponential lifetimes. Analysis of the donor-acceptor electronic coupling shows that for ionic liquids this intramolecular electron-transfer reaction should be treated using a solvent-controlled electron-transfer model.

Wishart J. F.; Lee, H.Y.; Issa, J.B.; Isied, S.S.; Castner, Jr., E.W.; Pan, Y.; Hussey, C.L.; Lee, K.S.

2012-03-01T23:59:59.000Z

114

Electron dynamics in complex environments with real-time time dependent density functional theory in a QM-MM framework  

SciTech Connect (OSTI)

This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrixrequired to propagate the electron dynamics, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data.

Morzan, Uriel N.; Ramrez, Francisco F.; Scherlis, Damin A., E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Departamento de Qumica Inorgnica, Analtica y Qumica Fsica/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, Buenos Aires (C1428EHA) (Argentina); Oviedo, M. Beln; Snchez, Cristin G. [Departamento de Matemtica y Fsica, Facultad de Ciencias Qumicas, INFIQC, Universidad Nacional de Crdoba, Ciudad Universitaria, X5000HUA Crdoba (Argentina)] [Departamento de Matemtica y Fsica, Facultad de Ciencias Qumicas, INFIQC, Universidad Nacional de Crdoba, Ciudad Universitaria, X5000HUA Crdoba (Argentina); Lebrero, Mariano C. Gonzlez, E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Instituto de Qumica y Fisicoqumica Biolgicas, IQUIFIB, CONICET (Argentina)] [Instituto de Qumica y Fisicoqumica Biolgicas, IQUIFIB, CONICET (Argentina)

2014-04-28T23:59:59.000Z

115

Phase-space dynamics of runaway electrons in tokamaks Xiaoyin Guan, Hong Qin, and Nathaniel J. Fisch  

E-Print Network [OSTI]

Phase-space dynamics of runaway electrons in tokamaks Xiaoyin Guan, Hong Qin, and Nathaniel J Received 9 February 2010; accepted 19 July 2010; published online 3 September 2010 The phase-space dynamics. A theoretical model and a numerical algorithm for the runaway dynamics in phase space are developed. Instead

116

Dynamic nuclear polarization with simultaneous excitation of electronic and nuclear transitions  

E-Print Network [OSTI]

Dynamic nuclear polarization transfers spin polarization from electrons to nuclei. We have achieved this by a new method, simultaneously exciting transitions of electronic and nuclear spins. The efficiency of this technique improves with increasing magnetic field. Experimental results are shown for N@C60 with continuous-wave microwaves, which can be expected to produce even higher polarization than the corresponding pulsed techniques for electron spins greater than 1/2. The degree of nuclear polarization in this case can be easily monitored through the intensities of the well resolved hyperfine components in the EPR spectrum. The nuclear spin-lattice relaxation time is orders of magnitude longer than that of the electrons.

G. W. Morley; K. Porfyrakis; A. Ardavan; J. van Tol

2008-05-28T23:59:59.000Z

117

Femtosecond time-resolved photoemission electron microscopy for spatiotemporal imaging of photogenerated carrier dynamics in semiconductors  

SciTech Connect (OSTI)

We constructed an instrument for time-resolved photoemission electron microscopy (TR-PEEM) utilizing femtosecond (fs) laser pulses to visualize the dynamics of photogenerated electrons in semiconductors on ultrasmall and ultrafast scales. The spatial distribution of the excited electrons and their relaxation and/or recombination processes were imaged by the proposed TR-PEEM method with a spatial resolution about 100 nm and an ultrafast temporal resolution defined by the cross-correlation of the fs laser pulses (240 fs). A direct observation of the dynamical behavior of electrons on higher resistivity samples, such as semiconductors, by TR-PEEM has still been facing difficulties because of space and/or sample charging effects originating from the high photon flux of the ultrashort pulsed laser utilized for the photoemission process. Here, a regenerative amplified fs laser with a widely tunable repetition rate has been utilized, and with careful optimization of laser parameters, such as fluence and repetition rate, and consideration for carrier lifetimes, the electron dynamics in semiconductors were visualized. For demonstrating our newly developed TR-PEEM method, the photogenerated carrier lifetimes around a nanoscale defect on a GaAs surface were observed. The obtained lifetimes were on a sub-picosecond time scale, which is much shorter than the lifetimes of carriers observed in the non-defective surrounding regions. Our findings are consistent with the fact that structural defects induce mid-gap states in the forbidden band, and that the electrons captured in these states promptly relax into the ground state.

Fukumoto, Keiki, E-mail: fukumoto.k.ab@m.titech.ac.jp; Yamada, Yuki; Matsuki, Takashi; Koshihara, Shin-ya [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan); Japan Science and Technology Agency JST-CREST, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Onda, Ken [Interactive Research Center of Science, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Japan Science and Technology Agency JST-PRESTO, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Mukuta, Tatsuhiko; Tanaka, Sei-ichi [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2014-08-15T23:59:59.000Z

118

Electron-rich sheath dynamics. I. Transient currents and sheath-plasma instabilities  

SciTech Connect (OSTI)

The evolution of an electron-rich sheath on a plane electrode has been investigated experimentally. A rapidly rising voltage is applied to a plane gridded electrode in a weakly ionized, low temperature, and field-free discharge plasma. Transient currents during the transition from ion-rich to electron-rich sheath are explained including the current closure. Time-resolved current-voltage characteristics of the electrode are presented. The time scale for the formation of an electron-rich sheath is determined by the ion dynamics and takes about an ion plasma period. When the ions have been expelled from the sheath a high-frequency sheath-plasma instability grows. The electric field contracts into the electron-rich sheath which implies that the potential outside the sheath drops. It occurs abruptly and creates a large current pulse on the electrode which is not a conduction but a displacement current. The expulsion of ions from the vicinity of the electrode lowers the electron density, electrode current, and the frequency of the sheath-plasma oscillations. Electron energization in the sheath creates ionization which reduces the space charge density, hence sheath electric field. The sheath-plasma instability is weakened or vanishes. The ionization rate decreases, and the sheath electric field recovers. A relaxation instability with repeated current transients can arise which is presented in a companion paper. Only for voltages below the ionization potential a quiescent electron rich-sheath is observed.

Stenzel, R. L. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Gruenwald, J.; Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

2011-06-15T23:59:59.000Z

119

Charge separation dynamics and opto-electronic properties of a diaminoterephthalate- C 60 diad  

E-Print Network [OSTI]

A novel diad composed of a diaminoterephthalate scaffold, covalently linked to a Fullerene derivative, is explored as a nanosized charge separation unit powered by solar energy. Its opto-electronic properties are studied and the charge separation rate is determined. Simulations of the coupled electronic and nuclear dynamics in the Ehrenfest approximation are carried out ona sub 100 fs time scale after photoexcitation in order to gain insights about the mechanisms driving the the charge separation. In particular, the role of vibronic coupling and of the detailed morphology are highlighted.

Pittalis, Stefano; Robin, Jrg; Freimuth, Lena; Christoffers, Jens; Rozzi, Christoph Lienaua nd Carlo Andrea

2014-01-01T23:59:59.000Z

120

Nano-electron beam induced current and hole charge dynamics through uncapped Ge nanocrystals  

SciTech Connect (OSTI)

Dynamics of hole storage in spherical Ge nanocrystals (NCs) formed by a two step dewetting/nucleation process on an oxide layer grown on an n-doped <001> silicon substrate is studied using a nano-electron beam induced current technique. Carrier generation is produced by an electron beam irradiation. The generated current is collected by an atomic force microscope--tip in contact mode at a fixed position away from the beam spot of about 0.5 {mu}m. This distance represents the effective diffusion length of holes. The time constants of holes charging are determined and the effect of the NC size is underlined.

Marchand, A.; El Hdiy, A.; Troyon, M. [Laboratoire de Recherche en Nanosciences, Bat. 6, case no 15, UFR Sciences, Universite de Reims Champagne Ardenne, 51687 Reims Cedex 2 (France); Amiard, G.; Ronda, A.; Berbezier, I. [IM2NP, Faculte des Sciences et Techniques, Campus de Saint Jerome - Case 142, Avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20 (France)

2012-04-16T23:59:59.000Z

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121

Quantum dynamics with fermion coupled coherent states: Theory and application to electron dynamics in laser fields  

SciTech Connect (OSTI)

We present an alternate version of the coupled-coherent-state method, specifically adapted for solving the time-dependent Schroedinger equation for multielectron dynamics in atoms and molecules. This theory takes explicit account of the exchange symmetry of fermion particles, and it uses fermion molecular dynamics to propagate trajectories. As a demonstration, calculations in the He atom are performed using the full Hamiltonian and accurate experimental parameters. Single- and double-ionization yields by 160-fs and 780-nm laser pulses are calculated as a function of field intensity in the range 10{sup 14}-10{sup 16} W/cm{sup 2}, and good agreement with experiments by Walker et al. is obtained. Since this method is trajectory based, mechanistic analysis of the dynamics is straightforward. We also calculate semiclassical momentum distributions for double ionization following 25-fs and 795-nm pulses at 1.5x10{sup 15} W/cm{sup 2}, in order to compare them with the detailed experiments by Rudenko et al. For this more challenging task, full convergence is not achieved. However, major effects such as the fingerlike structures in the momentum distribution are reproduced.

Kirrander, Adam [Laboratoire Aime Cotton du CNRS, Universite de Paris-Sud, Batiment 505, F-91405 Orsay (France); Shalashilin, Dmitrii V. [School of Chemistry, University of Leeds, Leeds LS2 9JT (United Kingdom)

2011-09-15T23:59:59.000Z

122

Nonadiabatic electron transfer at the nanoscale tin-oxide semiconductor/aqueous solution interface  

E-Print Network [OSTI]

are of considerable interest in the context of dye-sensitized liquid-junction cells for sunlight-to-electrical- energy forward and back electron transfer reactions involving molecular dyes and wide bandgap semiconductors conversion ­ for example, Grätzel cells.1­3 We have examined the kinetics of back electron transfer (b

123

Solvation of Magnesium Dication: Molecular Dynamics Simulation and Vibrational Spectroscopic Study of Magnesium Chloride in Aqueous Solutions  

E-Print Network [OSTI]

Solvation of Magnesium Dication: Molecular Dynamics Simulation and Vibrational Spectroscopic Study of Magnesium Chloride in Aqueous Solutions Karen M. Callahan, Nadia N. Casillas-Ituarte, Martina Roeselova 26, 2010 Magnesium dication plays many significant roles in biochemistry. While it is available

124

Excited states and electron transfer in solution : models based on density functional theory  

E-Print Network [OSTI]

Our understanding of organic materials for solar energy conversion stands to benefit greatly from accurate, computationally tractable electronic structure methods for excited states. Here we apply two approaches based on ...

Kowalczyk, Timothy Daniel

2012-01-01T23:59:59.000Z

125

Structural changes in block copolymer solution under shear flow as determined by nonequilibrium molecular dynamics  

E-Print Network [OSTI]

A nonequilibrium molecular dynamics computer simulation on microsegregated solutions of symmetrical diblock copolymers is reported. As the polymer concentration increases, the system undergoes phase transitions in the following order: body centered cubic (BCC) micelles, hexagonal (HEX) cylinders, gyroid (GYR) bicontinuous networks, and lamellae (L), which are the same morphologies that have been reported for block copolymer melts. Structural classification is based on the patterns of the anisotropic static structure factor and characteristic 3-dimensional images. The systems in the BCC micellar ($\\rho\\sigma^{3}=0.3$) and HEX cylindrical ($\\rho\\sigma^{3}=0.4$) phases were then subjected to a steady planar shear flow. In weak shear flow, the segregated domains in both systems tend to rearrange into sliding parallel close-packed layers with their normal in the direction of the shear gradient. At higher shear rates both systems adopt a perpendicular lamellar structure with the normal along the neutral direction. A further increase in the shear rate results in a decrease in lamellar spacing without any further structural transitions. Two critical shear rate values that correspond to the demarcation of different structural behaviors were found.

Igor Rychkov; Kenichi Yoshikawa

2003-10-06T23:59:59.000Z

126

Molecular dynamics of excited state intramolecular proton transfer: 3-hydroxyflavone in solution  

SciTech Connect (OSTI)

The ultrafast enol-keto photoisomerization in the lowest singlet excited state of 3-hydroxyflavone is investigated using classical molecular dynamics in conjunction with empirical valence bond (EVB) potentials for the description of intramolecular interactions, and a molecular mechanics and variable partial charge model, dependent on transferring proton position, for the description of solute-solvent interactions. A parallel multi-level genetic program was used to accurately fit the EVB potential energy surfaces to high level ab initio data. We have studied the excited state intramolecular proton transfer (ESIPT) reaction in three different solvent environments: methylcyclohexane, acetonitrile, and methanol. The effects of the environment on the proton transfer time and the underlying mechanisms responsible for the varied time scales of the ESIPT reaction rates are analyzed. We find that simulations with our EVB potential energy surfaces accurately reproduce experimentally determined reaction rates, fluorescence spectra, and vibrational frequency spectra in all three solvents. Furthermore, we find that the ultrafast ESIPT process results from a combination of ballistic transfer, and intramolecular vibrational redistribution, which leads to the excitation of a set of low frequency promoting vibrational modes. From this set of promoting modes, we find that an O-O in plane bend and a C-H out of plane bend are present in all three solvents, indicating that they are fundamental to the ultrafast proton transfer. Analysis of the slow proton transfer trajectories reveals a solvent mediated proton transfer mechanism, which is diffusion limited.

Bellucci, Michael A.; Coker, David F. [Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States)

2012-05-21T23:59:59.000Z

127

624 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 35, NO. 4, APRIL 1999 Dynamical Model of Directly Modulated  

E-Print Network [OSTI]

624 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 35, NO. 4, APRIL 1999 Dynamical Model of Directly coated at one end (z = 0) and has arbitrary reflectivity R 2 and transmissivity T 2 at the other (z = 0Lg

Sipe,J. E.

128

Electron spin resonance studies of two dimethoxymethane radicals in aqueous solution  

E-Print Network [OSTI]

-15 electron spin resonance (ESR) spectrometer was utili=ed in these studies. The g-values, a and y hyperfine splittings, and line widths were determined for each radical, and a com- puter program was used to generate a theoretical spectrum which... Electron Spin Resonance of Free Radicals One of the most general de initions that can be given for a f: ee radical is that of Ingram describing 15 it as "a molecule, or part of a molecule, in which the normal chemical binding has been modified so...

Lewis, Eileen Lob

2012-06-07T23:59:59.000Z

129

Ab initio molecular-dynamics study of the structural, vibrational, and electronic properties of glassy GeSe 2  

E-Print Network [OSTI]

Ab initio molecular-dynamics study of the structural, vibrational, and electronic properties We present results of an ab initio molecular-dynamics study of glassy GeSe2 using a 216 atom model static structure factors, and ring structures. The total static structure factor and first sharp

Drabold, David

130

Effects of energy loss on interaction dynamics of energetic electrons with plasmas C. K. Li and R. D. Petrasso  

E-Print Network [OSTI]

Effects of energy loss on interaction dynamics of energetic electrons with plasmas C. K. Li and R for energetic electrons interacting with plasmas. This model rigorously treats the effects of energy loss upon and energy loss--which previous calculations had erroneously treated as independent in cases where

131

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass-transition region  

E-Print Network [OSTI]

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass 2004; published online 17 February 2005 A phenomenological model of electron transfer reactions-acceptor energy gaps dashed line in Fig. 1 differs from the equilibrium distribution. The present phenomenological

Matyushov, Dmitry

132

Nickel recovery from electronic waste II Electrodeposition of Ni and NiFe alloys from diluted sulfate solutions  

SciTech Connect (OSTI)

Highlights: Ni can be recovered from EG wastes as pure Ni or as NiFe alloys. The control of the experimental conditions gives a certain alloy composition. Unusual deposits morphology shows different nucleation mechanisms for Ni vs Fe. The nucleation mechanism was progressive for Ni and instantaneous for Fe and NiFe. - Abstract: This study focuses on the electrodeposition of Ni and NiFe alloys from synthetic solutions similar to those obtained by the dissolution of electron gun (an electrical component of cathode ray tubes) waste. The influence of various parameters (pH, electrolyte composition, Ni{sup 2+}/Fe{sup 2+} ratio, current density) on the electrodeposition process was investigated. Scanning electron microscopy (SEM) and X-ray fluorescence analysis (XRFA) were used to provide information about the obtained deposits thickness, morphology, and elemental composition. By controlling the experimental parameters, the composition of the NiFe alloys can be tailored towards specific applications. Complementarily, the differences in the nucleation mechanisms for Ni, Fe and NiFe deposition from sulfate solutions have been evaluated and discussed using cyclic voltammetry and potential step chronoamperometry. The obtained results suggest a progressive nucleation mechanism for Ni, while for Fe and NiFe, the obtained data points are best fitted to an instantaneous nucleation model.

Robotin, B. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, RO-400028 Cluj-Napoca (Romania); Ispas, A. [Fachgebiet Elektrochemie und Galvanotechnik II, Technische Universitt Ilmenau, D-98693 Ilmenau (Germany); Coman, V. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, RO-400028 Cluj-Napoca (Romania); Bund, A. [Fachgebiet Elektrochemie und Galvanotechnik II, Technische Universitt Ilmenau, D-98693 Ilmenau (Germany); Ilea, P., E-mail: pilea@chem.ubbcluj.ro [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, RO-400028 Cluj-Napoca (Romania)

2013-11-15T23:59:59.000Z

133

Ultrafast time dynamics studies of periodic lattices with free electron laser radiation  

SciTech Connect (OSTI)

It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.

Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)

2012-11-01T23:59:59.000Z

134

Interfacial electron transfer dynamics of ru(II)-polypy6ridine sensitized TiO2  

SciTech Connect (OSTI)

Quantum dynamics simulations combined with density functional theory calculations are applied to study interfacial electron transfer (IET) from pyridine-4-phosphonic acid, [Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 2+} and [Ru(tpy)(bpy)(H{sub 2}O)-Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 4+} into the (101) surface of anatase TiO{sub 2}. IET rate from pyridine-4-phosphonic acid attached to the nanoparticle in bidentate mode ({tau} {approx} 100 fs) is an order of magnitude faster than the IET rate of the adsorbate attached in the monodentate mode ({tau} {approx} 1 ps). Upon excitation with visible light, [Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 2+} attached to TiO{sub 2} in bidentate binding mode will undergo IET with the rate of {approx} 1-10 ps, which is competitive with the excited state decay into the ground state. The probability of electron injection from [Ru(tpy)(bpy)(H{sub 2}O)-Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 4+} is rather low, as the excitation with visible light localizes the excited electron in the tpy-tpy bridge, which does not have favorable coupling with the TiO{sub 2} nanoparticle. The results are relevant to better understanding of the adsorbate features important for promoting efficient interfacial electron transfer into the semiconductor.

Jakubikova, Elena [Los Alamos National Laboratory; Martin, Richard L [Los Alamos National Laboratory; Batista, Enrique R [Los Alamos National Laboratory; Snoeberger, Robert C [YALE UNIV.; Batista, Victor S [YALE UNIV.

2009-01-01T23:59:59.000Z

135

Acceleration and dynamics of an electron in the degenerate and magnetized plasma elliptical waveguide  

SciTech Connect (OSTI)

The dynamics and energy gain of an electron in the field of a transverse magnetic wave propagating inside an elliptical degenerate plasma waveguide is analytically investigated by finding the field components of the TM{sub mr} mode in this waveguide. Besides, by solving the relativistic momentum and energy equations the deflection angle and the acceleration gradient of the electron in the waveguide are obtained. Furthermore, the field components of the hybrid mode and the transferred power in the presence of the magnetic field in this waveguide are found. Also by applying the boundary conditions at the plasma-conductor interface, we calculate the dispersion relation. It is shown that the cutoff frequency of this mode is dependent on the plasma density but independent of the magnetic field. Then, a single-electron model for numerical calculations of the electron deflection angle and acceleration gradient inside the magnetized plasma-filled elliptical waveguide is generally presented to be used as a cascading process for the acceleration purposes.

Abdoli-Arani, A.; Jazi, B. [Department of Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Shokri, B. [Physics Department and Laser-Plasma Research Institute, G. C. Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

2013-02-15T23:59:59.000Z

136

The reaction dynamics of alkali dimer molecules and electronically excited alkali atoms with simple molecules  

SciTech Connect (OSTI)

This dissertation presents the results from the crossed molecular beam studies on the dynamics of bimolecular collisions in the gas phase. The primary subjects include the interactions of alkali dimer molecules with simple molecules, and the inelastic scattering of electronically excited alkali atoms with O{sub 2}. The reaction of the sodium dimers with oxygen molecules is described in Chapter 2. Two reaction pathways were observed for this four-center molecule-molecule reaction, i.e. the formations of NaO{sub 2} + Na and NaO + NaO. NaO{sub 2} products exhibit a very anisotropic angular distribution, indicating a direct spectator stripping mechanism for this reaction channel. The NaO formation follows the bond breaking of O{sub 2}, which is likely a result of a charge transfer from Na{sub 2} to the excited state orbital of O{sub 2}{sup {minus}}. The scattering of sodium dimers from ammonium and methanol produced novel molecules, NaNH{sub 3} and Na(CH{sub 3}OH), respectively. These experimental observations, as well as the discussions on the reaction dynamics and the chemical bonding within these molecules, will be presented in Chapter 3. The lower limits for the bond dissociation energies of these molecules are also obtained. Finally, Chapter 4 describes the energy transfer between oxygen molecules and electronically excited sodium atoms.

Hou, H. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

1995-12-01T23:59:59.000Z

137

Simulations of the dissociation of small helium clusters with ab initio molecular dynamics in electronically excited states  

SciTech Connect (OSTI)

The dynamics resulting from electronic excitations of helium clusters were explored using ab initio molecular dynamics. The simulations were performed with configuration interaction singles and adiabatic classical dynamics coupled to a state-following algorithm. 100 different configurations of He{sub 7} were excited into the 2s and 2p manifold for a total of 2800 trajectories. While the most common outcome (90%) was complete fragmentation to 6 ground state atoms and 1 excited state atom, 3% of trajectories yielded bound, He {sub 2}{sup *}, and <0.5% yielded an excited helium trimer. The nature of the dynamics, kinetic energy release, and connections to experiments are discussed.

Closser, Kristina D.; Head-Gordon, Martin, E-mail: mhg@cchem.berkeley.edu [Department of Chemistry, University of California Berkeley, Berkeley, California 94720 (United States) [Department of Chemistry, University of California Berkeley, Berkeley, California 94720 (United States); Ultrafast X-Ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Gessner, Oliver [Ultrafast X-Ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Ultrafast X-Ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2014-04-07T23:59:59.000Z

138

The EGS4 Code System: Solution of gamma-ray and electron transport problems  

SciTech Connect (OSTI)

In this paper we present an overview of the EGS4 Code System -- a general purpose package for the Monte Carlo simulation of the transport of electrons and photons. During the last 10-15 years EGS has been widely used to design accelerators and detectors for high-energy physics. More recently the code has been found to be of tremendous use in medical radiation physics and dosimetry. The problem-solving capabilities of EGS4 will be demonstrated by means of a variety of practical examples. To facilitate this review, we will take advantage of a new add-on package, called SHOWGRAF, to display particle trajectories in complicated geometries. These are shown as 2-D laser pictures in the written paper and as photographic slides of a 3-D high-resolution color monitor during the oral presentation. 11 refs., 15 figs.

Nelson, W.R.; Namito, Yoshihito.

1990-02-09T23:59:59.000Z

139

ab initio Electronic Transport Model with Explicit Solution to the Linearized Boltzmann Transport Equation  

E-Print Network [OSTI]

Accurate models of carrier transport are essential for describing the electronic properties of semiconductor materials. To the best of our knowledge, the current models following the framework of the Boltzmann transport equation (BTE) either rely heavily on experimental data (i.e., semi-empirical), or utilize simplifying assumptions, such as the constant relaxation time approximation (BTE-cRTA). While these models offer valuable physical insights and accurate calculations of transport properties in some cases, they often lack sufficient accuracy -- particularly in capturing the correct trends with temperature and carrier concentration. We present here a general transport model for calculating low-field electrical drift mobility and Seebeck coefficient of n-type semiconductors, by explicitly considering all relevant physical phenomena (i.e. elastic and inelastic scattering mechanisms). We first rewrite expressions for the rates of elastic scattering mechanisms, in terms of ab initio properties, such as the ban...

Faghaninia, Alireza; Lo, Cynthia S

2015-01-01T23:59:59.000Z

140

Dynamics of the Aharonov-Bohm effect  

E-Print Network [OSTI]

The time-dependent Dirac equation is solved using the three-dimensional Finite Difference-Time Domain (FDTD) method. The dynamics of the electron wave packet in a vector potential is studied in the arrangements associated with the Aharonov-Bohm effect. The solution of the Dirac equation showed a change in the velocity of the electron wave packet even in a region where no fields of the unperturbed solenoid acted on the electron. The solution of the Dirac equation qualitatively agreed with the prediction of classical dynamics under the assumption that the dynamics was defined by the conservation of generalized or canonical momentum of the electron.

Neven Simicevic

2010-03-24T23:59:59.000Z

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


141

Quantifying Transient States in Materials with the Dynamic Transmission Electron Microscope  

SciTech Connect (OSTI)

The Dynamic Transmission Electron Microscope (DTEM) offers a means of capturing rapid evolution in a specimen through in-situ microscopy experiments by allowing 15 ns electron micrograph exposure times. The rapid exposure time is enabled by creating a burst of electrons at the emitter by ultraviolet pulsed laser illumination. This burst arrives a specified time after a second laser initiates the specimen reaction. The timing of the two Q-switched lasers is controlled by high-speed pulse generators with a timing error much less than the pulse duration. Both diffraction and imaging experiments can be performed, just as in a conventional TEM. The brightness of the emitter and the total current control the spatial and temporal resolutions. We have demonstrated 7 nm spatial resolution in single 15 ns pulsed images. These single-pulse imaging experiments have been used to study martensitic transformations, nucleation and crystallization of an amorphous metal, and rapid chemical reactions. Measurements have been performed on these systems that are possible by no other experimental approaches currently available.

Campbell, G; LaGrange, T; Kim, J; Reed, B; Browning, N

2009-09-21T23:59:59.000Z

142

Computation of the free energy due to electron density fluctuation of a solute in solution: A QM/MM method with perturbation approach combined with a theory of solutions  

SciTech Connect (OSTI)

We developed a perturbation approach to compute solvation free energy ?? within the framework of QM (quantum mechanical)/MM (molecular mechanical) method combined with a theory of energy representation (QM/MM-ER). The energy shift ? of the whole system due to the electronic polarization of the solute is evaluated using the second-order perturbation theory (PT2), where the electric field formed by surrounding solvent molecules is treated as the perturbation to the electronic Hamiltonian of the isolated solute. The point of our approach is that the energy shift ?, thus obtained, is to be adopted for a novel energy coordinate of the distribution functions which serve as fundamental variables in the free energy functional developed in our previous work. The most time-consuming part in the QM/MM-ER simulation can be, thus, avoided without serious loss of accuracy. For our benchmark set of molecules, it is demonstrated that the PT2 approach coupled with QM/MM-ER gives hydration free energies in excellent agreements with those given by the conventional method utilizing the Kohn-Sham SCF procedure except for a few molecules in the benchmark set. A variant of the approach is also proposed to deal with such difficulties associated with the problematic systems. The present approach is also advantageous to parallel implementations. We examined the parallel efficiency of our PT2 code on multi-core processors and found that the speedup increases almost linearly with respect to the number of cores. Thus, it was demonstrated that QM/MM-ER coupled with PT2 deserves practical applications to systems of interest.

Suzuoka, Daiki; Takahashi, Hideaki, E-mail: hideaki@m.tohoku.ac.jp; Morita, Akihiro [Department of Chemistry, Graduate School of Science, Tohoku University, Sendai Miyagi 980-8578 (Japan)] [Department of Chemistry, Graduate School of Science, Tohoku University, Sendai Miyagi 980-8578 (Japan)

2014-04-07T23:59:59.000Z

143

Non-smooth Dynamics Using Differential-algebraic Equations Perspective: Modeling and Numerical Solutions  

E-Print Network [OSTI]

mathematical tools. On the other hand, the approach based on differential-algebraic equations gives more insight into the constitutive assumptions of a chosen model and easier to obtain numerical solutions. Bingham-type models in which the force cannot...

Gotika, Priyanka

2012-02-14T23:59:59.000Z

144

Transverse dynamics of an intense electron bunch traveling through a pre-ionized plasma  

SciTech Connect (OSTI)

The propagation of a relativistic electron bunch through a plasma is an important problem in both plasma-wakefield acceleration and laser-wakefield acceleration. In those situations, the charge of the accelerated bunch is usually large enough to drive a relativistic wakefield, which then affects the transverse dynamics of the bunch itself. Yet to date, there is no fully relativistic, fully electromagnetic model that describes the generation of this wakefield and its feedback on the bunch. In this article, we derive a model which takes into account all the relevant relativistic and electromagnetic effects involved in the problem. A very good agreement is found between the model and the results of particle-in-cell simulations. The implications of high-charge effects for the transport of the bunch are discussed in detail.

Lehe, R., E-mail: remi.lehe@ensta.fr; Thaury, C.; Lifschitz, A.; Rax, J.-M.; Malka, V. [Laboratoire d'Optique Applique, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)] [Laboratoire d'Optique Applique, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2014-04-15T23:59:59.000Z

145

Structural, electronic, mechanical, and dynamical properties of graphene oxides: A first principles study  

SciTech Connect (OSTI)

We report the results of a theoretical study on the structural, electronic, mechanical, and vibrational properties of some graphene oxide models (GDO, a-GMO, z-GMO, ep-GMO and mix-GMO) at ambient pressure. The calculations are based on the ab-initio plane-wave pseudo potential density functional theory, within the generalized gradient approximations for the exchange and correlation functional. The calculated values of lattice parameters, bulk modulus, and its first order pressure derivative are in good agreement with other reports. A linear response approach to the density functional theory is used to derive the phonon frequencies. We discuss the contribution of the phonons in the dynamical stability of graphene oxides and detailed analysis of zone centre phonon modes in all the above mentioned models. Our study demonstrates a wide range of energy gap available in the considered models of graphene oxide and hence the possibility of their use in nanodevices.

Dabhi, Shweta D. [Department of Physics, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar 364001 (India); Gupta, Sanjay D. [V. B. Institute of Science, Department of Physics, C. U. Shah University, Wadhwan City - 363030, Surendranagar (India); Jha, Prafulla K., E-mail: prafullaj@yahoo.com [Department of Physics, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara-390002 (India)

2014-05-28T23:59:59.000Z

146

Exploring size and state dynamics in CdSe quantum dots using two-dimensional electronic spectroscopy  

SciTech Connect (OSTI)

Development of optoelectronic technologies based on quantum dots depends on measuring, optimizing, and ultimately predicting charge carrier dynamics in the nanocrystal. In such systems, size inhomogeneity and the photoexcited population distribution among various excitonic states have distinct effects on electron and hole relaxation, which are difficult to distinguish spectroscopically. Two-dimensional electronic spectroscopy can help to untangle these effects by resolving excitation energy and subsequent nonlinear response in a single experiment. Using a filament-generated continuum as a pump and probe source, we collect two-dimensional spectra with sufficient spectral bandwidth to follow dynamics upon excitation of the lowest three optical transitions in a polydisperse ensemble of colloidal CdSe quantum dots. We first compare to prior transient absorption studies to confirm excitation-state-dependent dynamics such as increased surface-trapping upon excitation of hot electrons. Second, we demonstrate fast band-edge electron-hole pair solvation by ligand and phonon modes, as the ensemble relaxes to the photoluminescent state on a sub-picosecond time-scale. Third, we find that static disorder due to size polydispersity dominates the nonlinear response upon excitation into the hot electron manifold; this broadening mechanism stands in contrast to that of the band-edge exciton. Finally, we demonstrate excitation-energy dependent hot-carrier relaxation rates, and we describe how two-dimensional electronic spectroscopy can complement other transient nonlinear techniques.

Caram, Justin R.; Zheng, Haibin; Rolczynski, Brian S.; Griffin, Graham B.; Engel, Gregory S., E-mail: gsengel@uchicago.edu [Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Dahlberg, Peter D. [Graduate Program in the Biophysical Sciences, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)] [Graduate Program in the Biophysical Sciences, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Dolzhnikov, Dmitriy S.; Talapin, Dmitri V. [Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)] [Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

2014-02-28T23:59:59.000Z

147

Development of an electron-temperature-dependent interatomic potential for molecular dynamics simulation of tungsten under electronic excitation  

E-Print Network [OSTI]

simulation of tungsten under electronic excitation S. Khakshouri,1,* D. Alf,1,2 and D. M. Duffy1,3 1

Alf, Dario

148

Dynamic environment coupling induce synchronized states in coupled time-delayed electronic circuits  

E-Print Network [OSTI]

We experimentally demonstrate the occurrence of various synchronized states in coupled piece-wise linear time-delayed electronic circuits using dynamic environment coupling where the environment has its own intrinsic dynamics via feedback from the circuits. We carry out these experiments in two different coupling configurations, namely mutual and subsystem coupling configurations. Depending upon the coupling strength and the nature of feedback, we observe a transition from nonsynchronization to complete synchronization via phase synchronization and from nonsynchronization to inverse synchronization via inverse-phase synchronization between the circuits in hyperchaotic regime. Snapshots of the time evolution, phase projection plots and localized sets of the circuits as observed experimentally from the oscilloscope, along with supporting numerical simulations confirm the existence of different synchronized states. Further, the transition to different synchronized states can be verified from the changes in the largest Lyapunov exponents, Correlation of Probability of Recurrence and Correlation Coefficient as a function of the coupling strength. We present a detailed linear stability analysis and obtain conditions for different synchronized states.

R. Suresh; K. Srinivasan; D. V. Senthilkumar; K. Murali; M. Lakshmanan; J. Kurths

2014-01-27T23:59:59.000Z

149

Closed-form Solutions to a Subclass of Continuous Stochastic Games via Symbolic Dynamic Programming  

E-Print Network [OSTI]

: a continuous state generalisation of matching pennies, binary option valuation and robust energy production optimisation, a problem for which closed- form solutions are generally unavailable. We present an exact closed stochastic games provide a convenient framework with which to model robust sequential optimisation in ad

Sanner, Scott

150

Detailed dynamics of electron beams self-trapped and accelerated in a self-modulated laser wakefield  

E-Print Network [OSTI]

. These features are explained by analysis and test particle simulations of electron dynamics during acceleration wave,1 such as the plasma wakefield accel- erator, the plasma beat-wave accelerator, the Laser Wake the linear dephasing limit, and explained it, using Particle-In-Cell PIC simulations, as a result

Umstadter, Donald

151

Semiconductor-Based Interfacial Electron-Transfer Reactivity: Decoupling Kinetics from pH-Dependent Band Energetics in a Dye-Sensitized Titanium Dioxide/Aqueous Solution  

E-Print Network [OSTI]

H-Dependent Band Energetics in a Dye-Sensitized Titanium Dioxide/Aqueous Solution System Susan G. Yan and Joseph T-bandgap semiconductors via attachment of redox-active dyes offers a means of sensitizing these materials for visible,3 As with other semiconductor/molecular dye assemblies, these work by electron injection from a photoexcited state

152

A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions  

SciTech Connect (OSTI)

We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10{sup ?1} mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

Arrell, C. A., E-mail: christopher.arrell@epfl.ch; Ojeda, J.; Mourik, F. van; Chergui, M. [Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fdrale de Lausanne, CH-1015 Lausanne (Switzerland); Sabbar, M.; Gallmann, L.; Keller, U. [Physics Department, ETH Zurich, 8093 Zurich (Switzerland); Okell, W. A.; Witting, T.; Siegel, T.; Diveki, Z.; Hutchinson, S.; Tisch, J. W.G.; Marangos, J. P. [Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Chapman, R. T.; Cacho, C.; Rodrigues, N.; Turcu, I. C.E.; Springate, E. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom)

2014-10-15T23:59:59.000Z

153

A heuristic algorithm for analytic solution of dynamic multiproduct liquid inventory systems considering shared storage  

E-Print Network [OSTI]

, . are assigned sequenti. ally to the products associated with the Kj ordered utili zatio? rates U 18 CHAPTER IV SOME SOLVED PROBLFHS The purpose of this chapter is to present the solution to several example problems. The first of these is the problem solved...A JJEURISTIC A!CORI'1 !F 1 F(J!1 ANALYTIC SOLJJ'1'10N 01" DYNAJlJC MJJITIPRODUCT J, ICJUIJJ INVE!iTORY SYSTEMS CONSIDJ:RING SJ!ARJ. :D STOJJAG!1 A Tncsis hy Joel Andre Massell Suhmi tted to tne Graouate College of the Texas API University...

Hassell, Joel Andre

2012-06-07T23:59:59.000Z

154

Numerical calculation of dynamical friction in electron cooling systems, including magnetic field perturbations and finite time effects  

SciTech Connect (OSTI)

The orders-of-magnitude higher luminosities required by future electron-ion collider concepts require a dissipative force to counteract the numerous factors acting to gradually increase the phase space volume of relativistic ion beams. High-energy electron cooling systems could provide the necessary dissipation via dynamical friction, but will have to be designed for new parameter regimes. It is expected that magnetic field errors, finite interaction time and other effects will reduce the dynamical friction and hence increase the cooling time, so improved understanding of the underlying dynamics is important. We present a generalized form of the classical field-free friction force equation, which conveniently captures some of these effects. Previous work (Bell et al 2008 J. Comput. Phys. 227 8714) shows both numerical and conceptual subtleties associated with undersampling of strong collisions, and we present a rigorous mathematical treatment of such difficulties, based on the use of a modified Pareto distribution for the electron-ion impact parameters. We also present a very efficient numerical algorithm for calculating the dynamical friction on a single ion in the field free case. For the case of arbitrary magnetic field errors, we present numerical simulation results, showing agreement with our generalized friction force formula.

Sobol, A.V.; Fedotov, A.; Bruhwiler, D.L.; Bell, G.I.; Litvinenko, V.

2010-09-24T23:59:59.000Z

155

Ultrafast probing of ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets  

SciTech Connect (OSTI)

The ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets are studied with time-resolved extreme ultraviolet ion imaging spectroscopy. At excitation energies of 23.6 {+-} 0.2 eV, Rydberg atoms in n= 3 and n= 4 states are ejected on different time scales and with significantly different kinetic energy distributions. Specifically, n= 3 Rydberg atoms are ejected with kinetic energies as high as 0.85 eV, but their appearance is delayed by approximately 200 fs. In contrast, n= 4 Rydberg atoms appear within the time resolution of the experiment with considerably lower kinetic energies. Major features in the Rydberg atom kinetic energy distributions for both principal quantum numbers can be described within a simple elastic scattering model of localized perturbed atomic Rydberg atoms that are expelled from the droplet due to their repulsive interaction with the surrounding helium bath. Time-dependent kinetic energy distributions of He{sub 2}{sup +} and He{sub 3}{sup +} ions are presented that support the formation of molecular ions in an indirect droplet ionization process and the ejection of neutral Rydberg dimers on a similar time scale as the n= 3 Rydberg atoms.

Buenermann, Oliver; Kornilov, Oleg; Neumark, Daniel M. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Haxton, Daniel J.; Gessner, Oliver [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Leone, Stephen R. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States)

2012-12-07T23:59:59.000Z

156

Postplasma particle dynamics in a Gaseous Electronics Conference RF Reference Cell  

SciTech Connect (OSTI)

Particle contamination in plasma tools used for the manufacture of very large scale integrated semiconductor devices on silicon wafers is a major cause of yield loss. Understanding the dynamics of particle movement in the postplasma regime is important to explain the process of their transport to the wafer. The movement of particle contamination in a Gaseous Electronics Conference RF Reference Cell in the postplasma regime was investigated using a novel technique. Particle clouds were observed using laser light scattering together with an image intensifier and a monochromator. This technique allowed particle clouds of low density, that could not otherwise be detected, to be seen. Video analysis of the particles showed movement of the cloud front during the first second after the plasma was extinguished. Using the particle terminal velocity to estimate particle size, we estimate diameters of 0.11 {mu}m in argon and 0.05 {mu}m in krypton. The role of the thermophoretic force on particles during the postplasma was shown to be larger than gravitational forces and to dominate particle transport for small particles under the conditions investigated. A temperature gradient of 12 {degree}C/cm was observed to move these particles away from a warm electrode as the plasma was extinguished and the particles were released from the electrostatic confinement forces generated by the plasma. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}

Collins, S.M. [Department of Electrical and Computer Engineering, University of Arizona, Tucson, Arizona 85721 (United States)] [Department of Electrical and Computer Engineering, University of Arizona, Tucson, Arizona 85721 (United States); Brown, D.A. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); O`Hanlon, J.F.; Carlile, R.N. [Department of Electrical and Computer Engineering, University of Arizona, Tucson, Arizona 85721 (United States)] [Department of Electrical and Computer Engineering, University of Arizona, Tucson, Arizona 85721 (United States)

1995-11-01T23:59:59.000Z

157

Investigation of Vortex Structures in Gas-Discharge Nonneutral Electron Plasma: II. Vortex Formation, Evolution and Dynamics  

E-Print Network [OSTI]

The results of experimental investigations of inhomogeneities of gas-discharge nonneutral electron plasma obtained by using the nonperturbing experimental methods [N.A. Kervalishvili, arXiv:1502.02516 [physics.plasm-ph] (2015)] have been presented. Inhomogeneities are the dense solitary vortex structures stretched along the magnetic field, the lifetime of which is much greater than the time of electron-neutral collisions. The processes of formation, evolution and dynamics of vortex structures were studied. The periodic sequence of these processes is described for different geometries of discharge device.

Kervalishvili, N A

2015-01-01T23:59:59.000Z

158

Numerical solutions of sheath structures in front of an electron-emitting electrode immersed in a low-density plasma  

SciTech Connect (OSTI)

The exact theoretical expressions involved in the formation of sheath in front of an electron emitting electrode immersed in a low-density plasma have been derived. The potential profile in the sheath region has been calculated for subcritical, critical, and supercritical emissions. The potential profiles of critical and supercritical emissions reveals that we must take into account a small, instead of zero, electric field at the sheath edge to satisfy the boundary conditions used to integrate the Poisson's equation. The I-V curves for critical emission shows that only high values of plasma-electron to emitted-electron temperature ratio can meet the floating potential of the emissive electrode. A one-dimensional fluid like model is assumed for ions, while the electron species are treated as kinetic. The distribution of emitted-electron from the electrode is assumed to be half Maxwellian. The plasma-electron enters the sheath region at sheath edge with half Maxwellian velocity distribution, while the reflected ones have cut-off velocity distribution due to the absorption of super thermal electrons by the electrode. The effect of varying emitted-electron current on the sheath structure has been studied with the help of a parameter G (the ratio of emitted-electron to plasma-electron densities)

Din, Alif [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, 44000 Islamabad (Pakistan)] [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, 44000 Islamabad (Pakistan)

2013-09-15T23:59:59.000Z

159

Excess electron relaxation dynamics at water/air interfaces dm Madarsz  

E-Print Network [OSTI]

of the relaxation of a ground state excess electron at interfaces of different phases of water with air with the surrounding water bath. The systems exhibiting the most stable SB excess electron states supercooled water to contain double acceptor-type water molecules in the close vicinity of the electron. These surface states

Simons, Jack

160

A master equation approach to the dynamics of zero electron kinetic energy (ZEKE) states and ZEKE spectroscopy  

SciTech Connect (OSTI)

We have theoretically studied important dynamic processes involved in zero electron kinetic energy (ZEKE) spectroscopy using the density matrix method with the inverse Born-Oppenheimer approximation basis sets. In ZEKE spectroscopy, the ZEKE Rydberg states are populated by laser excitation (either a one- or two-photon process), which is followed by autoionizations and l-mixing due to a stray field. The discrimination field is then applied to ionize loosely bound electrons in the ZEKE states. This is followed by using the extraction field to extract electrons from the ZEKE levels which have a strength comparable to that of the extraction field. These extracted electrons are measured for the relative intensities of the ion states under investigation. The spectral positions are determined by the applied laser wavelength and modified by the extraction electric field. In this paper, all of these processes are conducted within the context of the density matrix method. The density matrix method can provide not only the dynamics of system's population and coherence (or phase) but also the rate constants of the processes involved in the ZEKE spectroscopy. Numerical examples are given to demonstrate the theoretical treatments.

Wang, Yi-Hsieh [Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan (China); Mineo, H.; Chao, S. D. [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Selzle, H. L.; Neusser, H. J.; Schlag, E. W. [Institut fuer Physikalische und Theoretische Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Teranishi, Y. [Institute of Applied Chemistry, Institute of Molecular Science, Chiao-Tung University, Hsin-Chu, Taiwan (China); Lin, S. H. [Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan (China); Institute of Applied Chemistry, Institute of Molecular Science, Chiao-Tung University, Hsin-Chu, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China)

2011-02-14T23:59:59.000Z

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


161

Time-dependent restricted-active-space self-consistent-field singles method for many-electron dynamics  

E-Print Network [OSTI]

The time-dependent restricted-active-space self-consistent-field singles (TD-RASSCF-S) method is presented for investigating TD many-electron dynamics in atoms and molecules. Adopting the SCF notion from the muticonfigurational TD Hartree-Fock (MCTDHF) method and the RAS scheme (single-orbital excitation concept) from the TD configuration-interaction singles (TDCIS) method, the TD-RASSCF-S method can be regarded as a hybrid of them. We prove that, for closed-shell $N_{\\rm e}$-electron systems, the TD-RASSCF-S wave function can be fully converged using only $N_{\\rm e}/2+1\\le M\\le N_{\\rm e}$ spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with $M= N_{\\rm e}$ is more accurate than the TDCIS wave function. The accuracy of the TD-RASSCF-S approach over the TDCIS is illustrated by the calculation of high-order harmonic generation spectra for one-dimensional models of atomic helium, beryllium, and carbon in an intense laser pulse. The electronic dynamics during the process is investigated by analyzing the behavior of electron density and orbitals. The TD-RASSCF-S method is accurate, numerically tractable, and applicable for large systems beyond the capability of the MCTDHF method.

Haruhide Miyagi; Lars Bojer Madsen

2014-05-21T23:59:59.000Z

162

Time-dependent restricted-active-space self-consistent-field singles method for many-electron dynamics  

SciTech Connect (OSTI)

The time-dependent restricted-active-space self-consistent-field singles (TD-RASSCF-S) method is presented for investigating TD many-electron dynamics in atoms and molecules. Adopting the SCF notion from the muticonfigurational TD Hartree-Fock (MCTDHF) method and the RAS scheme (single-orbital excitation concept) from the TD configuration-interaction singles (TDCIS) method, the TD-RASSCF-S method can be regarded as a hybrid of them. We prove that, for closed-shell N{sub e}-electron systems, the TD-RASSCF-S wave function can be fully converged using only N{sub e}/2 + 1 ? M ? N{sub e} spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with M = N{sub e} is more accurate than the TDCIS wave function. The accuracy of the TD-RASSCF-S approach over the TDCIS is illustrated by the calculation of high-order harmonic generation spectra for one-dimensional models of atomic helium, beryllium, and carbon in an intense laser pulse. The electronic dynamics during the process is investigated by analyzing the behavior of electron density and orbitals. The TD-RASSCF-S method is accurate, numerically tractable, and applicable for large systems beyond the capability of the MCTDHF method.

Miyagi, Haruhide; Bojer Madsen, Lars [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)] [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)

2014-04-28T23:59:59.000Z

163

EQCM Investigations of Dye-Functionalized Nanocrystalline Titanium Dioxide Electrode/ Solution Interfaces: Does Luminescence Report Directly on Interfacial Electron Transfer  

E-Print Network [OSTI]

LETTERS EQCM Investigations of Dye-Functionalized Nanocrystalline Titanium Dioxide Electrode microbalance (EQCM) experiments have been performed on dye-functionalized nanocrystalline titanium dioxide electrode/solution interfaces. The experiments show that reversible, potential- induced dye desorption

164

Coordination and Hydrolysis of Plutonium Ions in Aqueous Solution using Car-Parrinello Molecular Dynamics Free Energy Simulations  

SciTech Connect (OSTI)

Car-Parrinello molecular dynamics (CPMD) simulations have been used to examine the hydration structures, coordination energetics and the first hydrolysis constants of Pu3+, Pu4+, PuO2+ and PuO22+ ions in aqueous solution at 300 K. The coordination numbers and structural properties of the first shell of these ions are in good agreement with available experimental estimates. The hexavalent PuO22+ species is coordinated to 5 aquo ligands while the pentavalent PuO2+ complex is coordinated to 4 aquo ligands. The Pu3+ and Pu4+ ions are both coordinated to 8 water molecules. The first hydrolysis constants obtained for Pu3+ and PuO22+ are 6.65 and 5.70 respectively, all within 0.3 pH units of the experimental values (6.90 and 5.50 respectively). The hydrolysis constant of Pu4+, 0.17, disagrees with the value of -0.60 in the most recent update of the Nuclear Energy Agency Thermochemical Database (NEA-TDB) but supports recent experimental findings. The hydrolysis constant of PuO2+, 9.51, supports the experimental results of Bennett et al. (Radiochim. Act. 1992, 56, 15). A correlation between the pKa of the first hydrolysis reaction and the effective charge of the plutonium center was found.

Odoh, Samuel O.; Bylaska, Eric J.; De Jong, Wibe A.

2013-11-27T23:59:59.000Z

165

A joint x-ray and neutron study on amicyanin reveals the role of protein dynamics in electron transfer  

SciTech Connect (OSTI)

The joint x-ray/neutron diffraction model of the Type I copper protein, amicyanin from Paracoccus denitrificans was determined at 1.8 {angstrom} resolution. The protein was crystallized using reagents prepared in D{sub 2}O. About 86% of the amide hydrogen atoms are either partially or fully exchanged, which correlates well with the atomic depth of the amide nitrogen atom and the secondary structure type, but with notable exceptions. Each of the four residues that provide copper ligands is partially deuterated. The model reveals the dynamic nature of the protein, especially around the copper-binding site. A detailed analysis of the presence of deuterated water molecules near the exchange sites indicates that amide hydrogen exchange is primarily due to the flexibility of the protein. Analysis of the electron transfer path through the protein shows that residues in that region are highly dynamic, as judged by hydrogen/deuterium exchange. This could increase the rate of electron transfer by transiently shortening through-space jumps in pathways or by increasing the atomic packing density. Analysis of C-H{hor_ellipsis}X bonding reveals previously undefined roles of these relatively weak H bonds, which, when present in sufficient number can collectively influence the structure, redox, and electron transfer properties of amicyanin.

Sukumar, N.; Mathews, F.S.; Langan, P.; Davidson, V.L. (Cornell); (UMMC); (WU-MED); (LANL)

2010-06-21T23:59:59.000Z

166

Effect of the Presence of Iodide on the Electron Injection Dynamics of Dye-Sensitized TiO2-Based Solar Cells  

E-Print Network [OSTI]

dynamics of dye-sensitized TiO2-based solar cells have been investigated to determine the effectsEffect of the Presence of Iodide on the Electron Injection Dynamics of Dye-Sensitized TiO2-Based Solar Cells Amanda L. Smeigh, Jordan E. Katz, Bruce S. Brunschwig,*,,§ Nathan S. Lewis,*, and James K

McCusker, James K.

167

ITP Aluminum: Aluminum Industry Vision: Sustainable Solutions...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Aluminum Industry Vision: Sustainable Solutions for a Dynamic World ITP Aluminum: Aluminum Industry Vision: Sustainable Solutions for a Dynamic World alumvision.pdf More Documents...

168

Beam dynamics performances and applications of a low-energy electron-beam magnetic bunch compressor  

E-Print Network [OSTI]

Many front-end applications of electron linear accelerators rely on the production of temporally-compressed bunches. The shortening of electron bunches is often realized with magnetic bunch compressors located in high-energy sections of accelerators. Magnetic compression is subject to collective effects including space charge and self interaction via coherent synchrotron radiation. In this paper we explore the application of magnetic compression to low-energy ($\\sim 40$ MeV), high-charge (nC) electron bunches with low normalized transverse emittances ($< 5$ $\\mu$m).

Prokop, C R; Carlsten, B E; Church, M

2013-01-01T23:59:59.000Z

169

Characterization and light-induced dynamics of alkanethiol-capped gold nanoparticles supracrystals by small-angle ultrafast electron diffraction  

E-Print Network [OSTI]

Metal nanoparticles (NPs) are promising candidates for applications from electronics to medicine. Their metallic core provides some key properties, e.g. magnetization, plasmonic response or conductivity, with the ligand molecules providing others like solubility, assembly or interaction with biomolecules. Even more properties can be engineered when these NPs are used as building blocks to form supracrystals. The formation of these supracrystals depends upon a complex interplay between many forces, some stemming from the core, some from the ligand. At present, there is no known approach to characterize the local order of ligand molecules in such complex supracrystals or their dynamics, with a spatial resolution ranging from the NPs cores and their ligands, to the larger scale domains arrangement. Here, we develop a methodology based on small-angle ultrafast electron diffraction to characterize different two-dimensional supracrystals of alkanethiol-coated gold nanoparticles with femtosecond time, sub-nanometer ...

Mancini, Giulia Fulvia; Pennacchio, Francesco; Reguera, Javier; Stellacci, Francesco; Carbone, Fabrizio

2015-01-01T23:59:59.000Z

170

ELECTRONIC SOLUTION SPECTRA FOR URANIUM AND NEPTUNIUM IN OXIDATION STATES (III) TO (VI) IN ANHYDROUS HYDROGEN FLUORIDE  

SciTech Connect (OSTI)

Spectra have been recorded for solutions in anhydrous hydrogen fluoride (AHF) of uranium and neptunium in oxidation states (III) to (VI). The spectra for U(III), Np(III) and Np(IV) in AHF are very similar to those in acidified aqueous solution, but that for U(IV) suggests that the cationic species is UF{sub 2}{sup 2+}. The AHF spectra for the elements in oxidation states (V) and (VI) are not comparable with those of the formally analogous aqueous solutions, where the elements exist as well-defined dioxo-cations. However, the AHF spectra can be related to spectra in the gas phase, in the solid state or in non-aqueous solvents for each element in its appropriate oxidation state.

Baluka, M.; Edelstein, N.; O'Donnell, T. A.

1980-10-01T23:59:59.000Z

171

High temperature electron spin dynamics in bulk cubic GaN: Nanosecond spin lifetimes far above room-temperature  

SciTech Connect (OSTI)

The electron spin dynamics in n-doped bulk cubic GaN is investigated for very high temperatures from 293?K up to 500?K by time-resolved Kerr-rotation spectroscopy. We find extraordinarily long spin lifetimes exceeding 1?ns at 500?K. The temperature dependence of the spin relaxation time is in qualitative agreement with predictions of Dyakonov-Perel theory, while the absolute experimental times are an order of magnitude shorter than predicted. Possible reasons for this discrepancy are discussed, including the role of phase mixtures of hexagonal and cubic GaN as well as the impact of localized carriers.

Bu, J. H.; Schaefer, A.; Hgele, D.; Rudolph, J. [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universitt Bochum, Universittsstrae 150, D-44780 Bochum (Germany); Schupp, T.; As, D. J. [Department of Physics, University of Paderborn, Warburger Str. 100, D-33095 Paderborn (Germany)

2014-11-03T23:59:59.000Z

172

The density matrix functional approach to electron correlation: Dynamic and nondynamic correlation along the full dissociation coordinate  

SciTech Connect (OSTI)

For chemistry an accurate description of bond weakening and breaking is vital. The great advantage of density matrix functionals, as opposed to density functionals, is their ability to describe such processes since they naturally cover both nondynamical and dynamical correlation. This is obvious in the Lwdin-Shull functional, the exact natural orbital functional for two-electron systems. We present in this paper extensions of this functional for the breaking of a single electron pair bond in N-electron molecules, using LiH, BeH{sup +}, and Li{sub 2} molecules as prototypes. Attention is given to the proper formulation of the functional in terms of not just J and K integrals but also the two-electron L integrals (K integrals with a different distribution of the complex conjugation of the orbitals), which is crucial for the calculation of response functions. Accurate energy curves are obtained with extended Lwdin-Shull functionals along the complete dissociation coordinate using full CI calculations as benchmark.

Mentel, ?. M.; Meer, R. van; Gritsenko, O. V. [Section Theoretical Chemistry, VU University, Amsterdam (Netherlands); Pohang University of Science and Technology, Pohang (Korea, Republic of); Baerends, E. J. [Section Theoretical Chemistry, VU University, Amsterdam (Netherlands); Pohang University of Science and Technology, Pohang (Korea, Republic of); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2014-06-07T23:59:59.000Z

173

Beam dynamics study of a 30?MeV electron linear accelerator to drive a neutron source  

SciTech Connect (OSTI)

An experimental neutron facility based on 32?MeV/18.47?kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E?=?30?MeV, P?=?18?kW, dE/E?electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5??10{sup 11}?n/cm{sup 2}/s/mA. Future development will be the real design of a 30?MeV electron linac based on S band traveling wave.

Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik, E-mail: hskang@postech.ac.kr [Pohang Accelerator Laboratory, San31, Hyoja-dong, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

2014-02-14T23:59:59.000Z

174

Aqueous systems from first-principles : structure, dynamics and electron-transfer reactions  

E-Print Network [OSTI]

In this thesis, we show for the first time how it is possible to calculated fully from first-principles the diabatic free-energy surfaces of electron-transfer reactions. The excitation energy corresponding to the transfer ...

Sit, Patrick Hoi Land

2006-01-01T23:59:59.000Z

175

Longitudinal Dynamics of Twin Electron Bunches in a High-energy Linac  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The recent development of two-color x-ray free-electron lasers, as well as the successful demonstration of high-gradient witness bunch acceleration in a plasma, have generated strong interest in electron bunch trains, where two or more electron bunches are generated, accelerated and compressed in the same accelerating bucket. In this paper we give a detailed analysis of a twin-bunch technique in a high-energy linac. This method allows the generation of two electron bunches with high peak current and independent control of time delay and energy separation. We #12;find that the wake#12;fields in the accelerator structures play an important role in the twin-bunch compression, and through analysis show that they can be used to extend the available time delay range. Based on the theoretical model and simulations we propose several methods to achieve larger time delay.

Zhang, Zhen; Ding, Yuantao; Marinelli, Agostino; Huang, Zhirong

2015-03-01T23:59:59.000Z

176

Electron dynamics of the buffer layer and bilayer graphene on SiC  

SciTech Connect (OSTI)

Angle- and time-resolved two-photon photoemission (TPPE) was used to investigate electronic states in the buffer layer of 4H-SiC(0001). An image potential state (IPS) series was observed on this strongly surface-bound buffer layer, and dispersion measurements indicated free-electron-like behavior for all states in this series. These results were compared with TPPE taken on bilayer graphene, which also show the existence of a free-electron-like IPS series. Lifetimes for the n?=?2, and n?=?3 states were obtained from time-resolved TPPE; slightly increased lifetimes were observed in the bilayer graphene sample for the n?=?2 the n?=?3 states. Despite the large band gap of graphene at the center of the Brillouin zone, the lifetime results demonstrate that the graphene layers do not behave as a simple tunneling barrier, suggesting that the buffer layer and graphene overlayers play a direct role in the decay of IPS electrons.

Shearer, Alex J.; Caplins, Benjamin W.; Suich, David E.; Harris, Charles B., E-mail: cbharris@berkeley.edu [Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Johns, James E. [Department of Chemistry, University of Minnesota Twin Cities, Minneapolis, Minnesota 55455 (United States); Hersam, Mark C. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)

2014-06-09T23:59:59.000Z

177

Coupled electron and ion nonlinear oscillations in a collisionless plasma  

SciTech Connect (OSTI)

Dynamics of coupled electrostatic electron and ion nonlinear oscillations in a collisionless plasma is studied with reference to a kinetic description. Proceeding from the exact solution of Vlasov-Maxwell equations written as a function of linear functions in the electron and ion velocities, we arrive at the two coupled nonlinear equations which describe the evolution of the system.

Karimov, A. R. [Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412, Russia and Department of Electrophysical Facilities, National Research Nuclear University MEPhI, Kashirskoye shosse 31, Moscow 115409 (Russian Federation)] [Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412, Russia and Department of Electrophysical Facilities, National Research Nuclear University MEPhI, Kashirskoye shosse 31, Moscow 115409 (Russian Federation)

2013-05-15T23:59:59.000Z

178

Mesoscopic structuring and dynamics of alcohol/water solutions probed by Terahertz Time-Domain Spectroscopy and Pulsed Field Gradient Nuclear Magnetic Resonance  

E-Print Network [OSTI]

in the structure of alcohol/water mixtures. Taking aqueous ethanol as a representative example, excess enthalpy, heat capacity, diffusivity, and viscosity all exhibit maxima or minima at ?15?20 mol %;12,16,20?23 this is attributable to Received: March 20, 2014... dielectric spectroscopy and the results were compared to femtosecond infrared pump? probe studies. By investigating a range of concentrations of aqueous tetramethylurea solutions it was found that the dynamics of the water molecules in close vicinity...

Li, Ruoyu; D'Agostino, Carmine; McGregor, James; Mantle, Michael D.; Zeitler, J. Axel; Gladden, Lynn F.

2014-08-12T23:59:59.000Z

179

The structural, electronic and dynamic properties of the L1{sub 2}- type Co{sub 3}Ti alloy  

SciTech Connect (OSTI)

The structural, electronic and dynamic properties of the cubic Co{sub 3}Ti alloy in L1{sub 2} structure have been investigated using a pseudopotential plane wave (PP-PW) method within the generalized gradient approximation proposed by PerdewBurkeErnzerhof (GGA-PBE). The structural properties, including the lattice constant, the bulk modulus and its pressure derivative agree reasonably with the previous results. The density of state (DOS), projected density of state (PDOS) and electronic band structure are also reported. The DOS shows that Co{sub 3}Ti alloy has a metallic character since the energy bands cross the Fermi level. The density of states at Fermi level mainly comes from the Co-3d states. Phonon dispersion curves and their corresponding total densities of states were obtained using a linear response in the framework of the density functional perturbation theory. All computed phonon frequencies are no imaginer and thus, Co{sub 3}Ti alloy is dynamically stable. The zone center phonon modes have been founded to be 9.307, 9.626 and 13.891 THz for Co{sub 3}Ti.

Arikan, Nihat [Ahi Evran niversitesi E?itim Fakltesi, ?lk?retim Blm, K?r?ehir (Turkey); zduran, Mustafa [Ahi Evran niversitesi, Fen Edebiyat Fakltesi, Fizik Blm, K?r?ehir (Turkey)

2014-10-06T23:59:59.000Z

180

The VENUS/NWChem Software Package. Tight Coupling Between Chemical Dynamics Simulations and Electronic Structure Theory  

SciTech Connect (OSTI)

The interface for VENUS and NWChem, and the resulting software package for direct dynamics simulations are described. The coupling of the two codes is considered to be a tight coupling. The two codes are compiled and linked together and act as one executable with data being passed between the two codes through routine calls. The advantages of this type of coupling are discussed. The interface has been designed to have as little interference as possible with the core codes of both VENUS and NWChem. VENUS is the code that propagates the direct dynamics trajectories and, therefore, is the program that drives the overall execution of VENUS/NWChem. VENUS has remained an essentially sequential code, which uses the highly parallel structure of NWChem. Subroutines of the interface which accomplish the data transmission and communication between the two computer programs are described. Recent examples of the use of VENUS/NWChem for direct dynamics simulations are summarized.

Lourderaj, Upakarasamy; Sun, Rui; De Jong, Wibe A.; Windus, Theresa L.; Hase, William L.

2014-03-01T23:59:59.000Z

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181

Dynamics of ion acoustic double layers in a magnetized two-population electrons plasma  

SciTech Connect (OSTI)

The obliquely propagating ion acoustic (IA) double-layers are investigated in a magnetized two population electron plasmas. The extended Kortewegde Vries equation is derived by using the reductive perturbation technique. The effect of obliqueness (l{sub z}) and magnitude of the external magnetic field (?{sub ci}), as well as the electron number density (?) on the double-layer profile, is studied, and then the ranges of parameters for which the double-layers exist are investigated in detail. We found that the combined effects of l{sub z}, ?{sub ci}, and ? significantly modify the basic properties (viz. amplitude and width) of the IA double-layers.

Shahmansouri, M. [Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349 (Iran, Islamic Republic of)

2013-10-15T23:59:59.000Z

182

Ab initio calculation of proton-coupled electron transfer rates using the external-potential representation: A ubiquinol complex in solution  

SciTech Connect (OSTI)

In quantum-mechanical/molecular-mechanical (QM/MM) treatment of chemical reactions in condensed phases, one solves the electronic Schroedinger equation for the solute (or an active site) under the electrostatic field from the environment. This Schroedinger equation depends parametrically on the solute nuclear coordinates R and the external electrostatic potential V. This fact suggests that one may use R and V as natural collective coordinates for describing the entire system, where V plays the role of collective solvent variables. In this paper such an (R,V) representation of the QM/MM canonical ensemble is described, with particular focus on how to treat charge transfer processes in this representation. As an example, the above method is applied to the proton-coupled electron transfer of a ubiquinol analog with phenoxyl radical in acetonitrile solvent. Ab initio free-energy surfaces are calculated as functions of R and V using the reference interaction site model self-consistent field method, the equilibrium points and the minimum free-energy crossing point are located in the (R,V) space, and then the kinetic isotope effects (KIEs) are evaluated approximately. The results suggest that a stiffer proton potential at the transition state may be responsible for unusual KIEs observed experimentally for related systems.

Yamamoto, Takeshi; Kato, Shigeki [Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)

2007-06-14T23:59:59.000Z

183

Dynamics of the electric current in an ideal electron gas: a sound mode inside the quasi-particles  

E-Print Network [OSTI]

We study the equation of motion for the Noether current in an electron gas within the framework of the Schwinger-Keldysh Closed-Time-Path formalism. The equation is shown to be highly non-linear and irreversible even for a non-interacting, ideal gas of electrons at non-zero density. We truncate the linearised equation of motion, written as the Laurent series in Fourier space, so that the resulting expressions are local in time, both at zero and at small finite temperatures. Furthermore, we show that the one-loop Coulomb interactions only alter the physical picture quantitatively, while preserving the characteristics of the dynamics that the electric current exhibits in the absence of interactions. As a result of the composite nature of the Noether current, composite sound waves are found to be the dominant IR collective excitations at length scales between the inverse Fermi momentum and the mean free path that would exist in an interacting electron gas. We also discuss the difference and the transition betwee...

Grozdanov, Sao

2015-01-01T23:59:59.000Z

184

Dynamics of the electric current in an ideal electron gas: a sound mode inside the quasi-particles  

E-Print Network [OSTI]

We study the equation of motion for the Noether current in an electron gas within the framework of the Schwinger-Keldysh Closed-Time-Path formalism. The equation is shown to be highly non-linear and irreversible even for a non-interacting, ideal gas of electrons at non-zero density. We truncate the linearised equation of motion, written as the Laurent series in Fourier space, so that the resulting expressions are local in time, both at zero and at small finite temperatures. Furthermore, we show that the one-loop Coulomb interactions only alter the physical picture quantitatively, while preserving the characteristics of the dynamics that the electric current exhibits in the absence of interactions. As a result of the composite nature of the Noether current, composite sound waves are found to be the dominant IR collective excitations at length scales between the inverse Fermi momentum and the mean free path that would exist in an interacting electron gas. We also discuss the difference and the transition between the hydrodynamical regime of an ideal gas, defined in this work, and the hydrodynamical regime in phenomenological hydrodynamics, which is normally used for the description of interacting gases.

Sao Grozdanov; Janos Polonyi

2015-01-26T23:59:59.000Z

185

Nonadiabatic Molecular Dynamics Study of Electron Transfer from Alizarin to the Hydrated Ti4+ Ion  

E-Print Network [OSTI]

The dye-sensitized nanocrystalline solar cell, also known as the Gra¨tzel cell, is a promising alternative that forms the basis of the Gra¨tzel type solar cell. The experimental data and electronic structure to the more costly traditional solar cell.1-5 It employs organic or transition-metal- based chromophores

186

Dynamic and Electronic Transport Properties of DNA Translocation through Graphene Nanopores  

E-Print Network [OSTI]

alternative for accurate and low-cost DNA read- outs has been explored by means of single-molecule sequencing an energy shift, we observed that the graphene pore manifests selectiveness toward DNA nucleobases. KEYWORDS techniques using artificial nanopore membranes mostly fabricated via ion/electron beam techniques. Biological

Cuniberti, Gianaurelio

187

Gyrokinetic and Gyrofluid Models for Zonal Flow Dynamics in Ion and Electron Temperature Gradient Turbulence  

SciTech Connect (OSTI)

Collisionless time evolution of zonal flows in ion and electron temperature gradient turbulence in toroidal plasmas is investigated. The responses of the zonal-flow potential to the initial perturbation and to the turbulence source are determined from the gyrokinetic equations combined with the Poisson equation, A novel gyrofluid model is presented, which properly describes the zonal-flow time evolution and reproduces the same residual zonal-flow levels as predicted by the gyrokinetic model.

Sugama, H.; Watanabe, T.-H. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan); Graduate University for Advanced Studies, Toki, Gifu, 509-5292 (Japan); Ferrando i Margalet, S. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan)

2006-11-30T23:59:59.000Z

188

Solving the Accelerator-Condenser Coupling Problem in a Nanosecond Dynamic Transmission Electron Microscope  

SciTech Connect (OSTI)

We describe a modification to a transmission electron microscope (TEM) that allows it to briefly (using a pulsed-laser-driven photocathode) operate at currents in excess of 10 mA while keeping the effects of condenser lens aberrations to a minimum. This modification allows real-space imaging of material microstructure with a resolution of order 10 nm over regions several {micro}m across with an exposure time of 15 ns. This is more than 6 orders of magnitude faster than typical video-rate TEM imaging. The key is the addition of a weak magnetic lens to couple the large-diameter high-current beam exiting the accelerator into the acceptance aperture of a conventional TEM condenser lens system. We show that the performance of the system is essentially consistent with models derived from ray tracing and finite element simulations. The instrument can also be operated as a conventional TEM by using the electron gun in a thermionic mode. The modification enables very high electron current densities in {micro}m-sized areas and could also be used in a non-pulsed system for high-throughput imaging and analytical TEM.

Reed, B W; LaGrange, T; Shuttlesworth, R M; Gibson, D J; Campbell, G H; Browning, N D

2009-12-29T23:59:59.000Z

189

Probing the Degradation Mechanisms in Electrolyte Solutions for Li-ion Batteries by In-Situ Transmission Electron Microscopy  

SciTech Connect (OSTI)

One of the goals in the development of new battery technologies is to find new electrolytes with increased electrochemical stability. In-situ (scanning) transmission electron microscopy ((S)TEM) using an electrochemical fluid cell provides the ability to rapidly and directly characterize electrode/electrolyte interfacial reactions under battery relevant electrochemical conditions. Furthermore, as the electron beam itself causes a localized electrochemical reaction when it interacts with the electrolyte, the breakdown products that occur during the first stages of battery operation can potentially be simulated and characterized using a straightforward in-situ liquid stage (without electrochemical biasing capabilities). In this paper, we have studied the breakdown of a range of inorganic/salt complexes that are used in state-of-the-art Li-ion battery systems. The results of the in-situ (S)TEM experiments matches with previous stability tests performed during battery operation and the breakdown products and mechanisms are also consistent with known mechanisms. This analysis indicates that in-situ liquid stage (S)TEM observations can be used to directly test new electrolyte designs and provide structural insights into the origin of the solid electrolyte interphase (SEI) formation mechanism.

Abellan Baeza, Patricia; Mehdi, Beata L.; Parent, Lucas R.; Gu, Meng; Park, Chiwoo; Xu, Wu; Zhang, Yaohui; Arslan, Ilke; Zhang, Jiguang; Wang, Chong M.; Evans, James E.; Browning, Nigel D.

2014-02-21T23:59:59.000Z

190

Time-resolved reflectivity techniques for dynamic studies of electron beam recrystallization of silicon-on-insulator films  

SciTech Connect (OSTI)

A time-resolved reflectivity (TRR) technique has been developed for dynamic studies of swept beam heating of silicon-on-insulator (SOI) materials. The method exploits the temperature dependence of the reflectivity of SOI films to allow noncontact temperature measurement with high spatial and temporal resolution. This technique is of considerable practical importance for beam processing, since it allows the temperature distribution induced by a beam being scanned across a specimen to be determined. The temperature distribution produced by a line electron beam swept across a SOI specimen was experimentally measured and found to be consistent with a theoretical prediction. The TRR technique can also be used to study melting and will prove useful for characterizing zone melting recrystallization, where thermal modeling is often inadequate for the complex structures involved.

Timans, P.J.; McMahon, R.A.; Ahmed, H.

1988-11-07T23:59:59.000Z

191

Relativistic nonlinear dynamics of an intense laser beam propagating in a hot electron-positron magnetoactive plasma  

SciTech Connect (OSTI)

The present study is devoted to investigation of the nonlinear dynamics of an intense laser beam interacting with a hot magnetized electron-positron plasma. Propagation of the intense circularly polarized laser beam along an external magnetic field is studied using a relativistic two-fluid model. A modified nonlinear Schrdinger equation is derived based on the quasi-neutral approximation, which is valid for hot plasma. Light envelope solitary waves and modulation instability are studied, for one-dimensional case. Using a three-dimensional model, spatial-temporal development of laser pulse is investigated. Occurrence of some nonlinear phenomena such as self-focusing, self-modulation, light trapping, and filamentation of laser pulse is discussed. Also the effect of external magnetic field and plasma temperature on the nonlinear evolution of these phenomena is studied.

Sepehri Javan, N.; Adli, F. [Department of Physics, Faculty of Sciences, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil 56199-11367 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Sciences, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil 56199-11367 (Iran, Islamic Republic of)

2013-06-15T23:59:59.000Z

192

Gas mixing system for imaging of nanomaterials under dynamic environments by environmental transmission electron microscopy  

SciTech Connect (OSTI)

A gas mixing manifold system that is capable of delivering a stable pressure stream of a desired composition of gases into an environmental transmission electron microscope has been developed. The system is designed to provide a stable imaging environment upon changes of either the composition of the gas mixture or upon switching from one gas to another. The design of the system is described and the response of the pressure inside the microscope, the sample temperature, and sample drift in response to flow and composition changes of the system are reported.

Akatay, M. Cem [School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)] [School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Zvinevich, Yury; Ribeiro, Fabio H., E-mail: fabio@purdue.edu, E-mail: estach@bnl.gov [Forney Hall of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Baumann, Philipp [Computer Sciences, University of Applied Sciences of Northeastern Switzerland, 4132 Muttenz, Switzerland and Department of Physics, Yeshiva University, New York, New York 10016 (United States)] [Computer Sciences, University of Applied Sciences of Northeastern Switzerland, 4132 Muttenz, Switzerland and Department of Physics, Yeshiva University, New York, New York 10016 (United States); Stach, Eric A., E-mail: fabio@purdue.edu, E-mail: estach@bnl.gov [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2014-03-15T23:59:59.000Z

193

Photochemical charge separation in zeolites: Electron transfer dynamics, nanocrystals and zeolitic membranes. Final technical report  

SciTech Connect (OSTI)

Aluminosilicate zeolites provide an excellent host for photochemical charge separation. Because of the constraints provided by the zeolite, the back electron transfer from the reduced acceptor to the oxidized sensitizer is slowed down. This provides the opportunity to separate the charge and use it in a subsequent reaction for water oxidation and reduction. Zeolite-based ruthenium oxide catalysts have been found to be efficient for the water splitting process. This project has demonstrated the usefulness of zeolite hosts for photolytic splitting of water.

Dutta, Prabir K.

2001-09-30T23:59:59.000Z

194

Long-Lived Electronic Coherence in Dissipative Exciton-Dynamics of Light-Harvesting Complexes  

E-Print Network [OSTI]

The observed prevalence of oscillatory signals in the spectroscopy of biological light-harvesting complexes at ambient temperatures has led to a search for mechanisms supporting coherent transport through larger molecules in noisy environments. We demonstrate a generic mechanism supporting long-lasting electronic coherence up to 0.3 ps at a temperature of 277 K. The mechanism relies on two properties of the spectral density: (i) a large dissipative coupling to a continuum of higher-frequency vibrations required for efficient transport and (ii) a small slope of the spectral density at zero frequency.

Christoph Kreisbeck; Tobias Kramer

2012-07-26T23:59:59.000Z

195

Probing Electron Transfer Dynamics at MgO Surfaces by Mg-Atom Desorption. |  

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196

Time-resolved THz studies of carrier dynamics in semiconductors, superconductors, and strongly-correlated electron materials  

SciTech Connect (OSTI)

Perhaps the most important aspect of contemporary condensed matter physics involves understanding strong Coulomb interactions between the large number of electrons in a solid. Electronic correlations lead to the emergence of new system properties, such as metal-insulator transitions, superconductivity, magneto-resistance, Bose-Einstein condensation, the formation of excitonic gases, or the integer and fractional Quantum Hall effects. The discovery of high-Tc superconductivity in particular was a watershed event, leading to dramatic experimental and theoretical advances in the field of correlated-electron systems. Such materials often exhibit competition between the charge, lattice, spin, and orbital degrees of freedom, whose cause-effect relationships are difficult to ascertain. Experimental insight into the properties of solids is traditionally obtained by time-averaged probes, which measure e.g., linear optical spectra, electrical conduction properties, or the occupied band structure in thermal equilibrium. Many novel physical properties arise from excitations out of the ground state into energetically higher states by thermal, optical, or electrical means. This leads to fundamental interactions between the system's constituents, such as electron-phonon and electron-electron interactions, which occur on ultrafast timescales. While these interactions underlie the physical properties of solids, they are often only indirectly inferred from time-averaged measurements. Time-resolved spectroscopy, consequently, is playing an ever increasing role to provide insight into light-matter interaction, microscopic processes, or cause-effect relationships that determine the physics of complex materials. In the past, experiments using visible and near-infrared femtosecond pulses have been extensively employed, e.g. to follow relaxation and dephasing processes in metals and semiconductors. However, many basic excitations in strongly-correlated electron systems and nanoscale materials occur at lower energies. The terahertz (THz) regime is particularly rich in such fundamental resonances. This includes ubiquitous lattice vibrations and low-energy collective oscillations of conduction charges. In nanoscale materials, band structure quantization also yields novel infrared and THz transitions, including intersubband absorption in quantum wells. The formation of excitons in turn leads to low-energy excitations analogous to inter-level transitions in atoms. In transition-metal oxides, fundamental excitation gaps arise from charge pairing into superconducting condensates and other correlated states. This motivates the use of ultrafast THz spectroscopy as a powerful tool to study light-matter interactions and microscopic processes in nanoscale and correlated-electron materials.A distinct advantage of coherent THz pulses is that the amplitude and phase of the electric field can be measured directly, as the THz fields are coherent with the fs pulses from which they are generated. Using THz time-domain spectroscopy (THz-TDS), both the real and imaginary parts of the response functions (such as the dielectric function) are obtained directly without the need for Kramers?Kronig transforms. The THz response can also be expressed in terms of absorption and refractive index, or as the optical conductivity. The optical conductivity describes the current response of a many-body system to an electric field, an ideal tool to study conducting systems. A second important advantage is the ultrafast time resolution that results from the short temporal duration of the THz time-domain sources. In particular, optical-pump THz-probe spectroscopy enables a delicate probe of the transient THz conductivity after optical photoexcitation. These experiments can provide insight into quasiparticle interactions, phase transitions, or nonequilibrium dynamics. In this chapter we will provide many such examples. Since THz spectroscopy of solids is a quickly expanding field

Kaindl, Robert A.; Averitt, Richard D.

2006-11-14T23:59:59.000Z

197

Modeling surfaces in the context of pulsed-power : work functions, electron emission and dynamic response.  

SciTech Connect (OSTI)

The ability to quickly understand and deal with issues on ZR, or to virtually design a future ZX accelerator, requires a physics-based capability to simulate all key pulsed power components. Highly important for gas switches and transmission lines are surface phenomena: thermionic emission, photoemission, field emission, and ion-surface dynamics. These are complex processes even at normal conditions, when coupled to the dynamic environment in pulsed power components, the current state of the art of understanding is not at the level of science based predictive modeling. Modeling efforts at the macroscopic level (finite element based hydrodynamic simulations) require detailed information of these processes to yield more reliable results. This is the final report of an LDRD project in the science of extreme environments investment area; the project was focused on describing the physics of surfaces of materials of interest in pulsed-power components. We have calculated the temperature dependence of work functions for metals from first principles using density functional theory (DFT) as well as investigated the effect of initial oxidation and alloying. By using the GW method, we have gone beyond DFT to calculate work functions for Al. The GW work required base-lining the GW results for different systems, since GW lacks a description of total energy. Lastly, we investigated the more macroscopic physics of how a surface and bulk material responds to a very high current under a short time, representative for current loads in pulsed-power components, with emphasis on materials modeling. These simulations were made using two hydrodynamic codes, ALEGRA and MACH2, in order to focus on the materials models themselves.

Cochrane, Kyle Robert (Ktech Corporation, Albuquerque, NM); Chantrenne, Sophie (SAIC, Albuquerque, NM); Mattsson, Thomas Kjell Rene; Faleev, Sergey V. (SNAMI Inc., AL)

2009-09-01T23:59:59.000Z

198

Nonequilibrium quasiparticle relaxation dynamics in single crystals of hole- and electron-doped BaFe[subscript 2]As[subscript 2  

E-Print Network [OSTI]

We report on the nonequilibrium quasiparticle dynamics in BaFe[subscript 2]As[subscript 2] on both the hole-doped (Ba[subscript 1?x]K[subscript x]Fe[subscript 2]As[subscript 2]) and electron-doped (BaFe[subscript ...

Torchinsky, Darius Hosseinzadeh

199

Electronic and dynamic studies of boron carbide nanowires D. N. McIlroy, Daqing Zhang, Robert M. Cohen, and J. Wharton  

E-Print Network [OSTI]

Electronic and dynamic studies of boron carbide nanowires D. N. McIlroy, Daqing Zhang, Robert M and vibrational properties of boron carbide nanowires grown by plasma-enhanced chemical vapor deposition have been. The NEXAFS spectra are equivalent to corresponding spectra of single-crystal (B4C) boron carbide, consistent

Gilbert, Pupa Gelsomina De Stasio

200

The elasto-/hydro-dynamics of quasicrystals with 12- and 18-fold symmetries in some soft matters and mathematical solutions  

E-Print Network [OSTI]

The observation recently of 12-fold quasicrystals in polymers, nanoparticle mixture and 12-fold and 18-fold quasicrystals in colloidal solutions are important events for the study of quasicrystals. To describe the mechanical behaviour we propose a new solid-liquid phase quasicrystal model for some soft matters including polymers and colloids. The so-called new solid-liquid phase, is a new phase model of anisotropic fluid, but different from liquid crystal phase, here the structure presents quasiperiodic symmetry. Based on the model, the elasticity, fluidity and viscosity of the material have been studied, the relevant mathematical theory has also been proposed. Some mathematical solutions of the theory are discussed.

Tian You Fan

2012-10-05T23:59:59.000Z

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201

Instrumentation and Beam Dynamics Study of Advanced Electron-Photon Facility in Indiana University  

SciTech Connect (OSTI)

The Advanced eLectron-PHoton fAcility (ALPHA) is a compact electron accelerator under construction and being commissioned at the Indiana University Center for Exploration of Energy and Matter (CEEM). In this thesis, we have studied the refurbished Cooler Injector Synchrotron (CIS) RF cavity using both the transmission line model and SUPERFISH simulation. Both low power and high power RF measurements have been carried out to characterize the cavity. Considering the performance limit of ferrite, we have designed a new ferrite loaded, co-axial quarter wave like cavity with similar structure but a more suitable ferrite material. We have also designed a traveling wave stripline kicker for fast extraction by POISSON and Microwave Studio. The strips geometry is trimmed to maximize the uniformity of the kicking field and match the impedance of the power cables. The time response simulation shows the kicker is fast enough for machine operation. The pulsed power supply requirement has also been specified. For the beam diagnosis in the longitudinal direction, we use a wideband Wall Gap Monitor (WGM) served in CIS. With proper shielding and amplification to get good WGM signal, we have characterized the injected and extracted beam signal in single pass commissioning, and also verified the debunching effect of the ALPHA storage ring. A modulation-demodulation signal processing method is developed to measure the current and longitudinal profile of injected beam. By scanning the dipole strength in the injection line, we have reconstructed the tomography of the longitudinal phase space of the LINAC beam. In the accumulation mode, ALPHA will be operated under a low energy and high current condition, where intra beam scattering (IBS) becomes a dominant effect on the beam emittance. A self consistent simulation, including IBS effect, gas scattering and linear coupling, has been carried out to calculate the emittance of the stored beam.

Luo, Tianhuan; /Indiana U.

2011-08-01T23:59:59.000Z

202

SISGR: Water dynamics in heterogeneous and confined environments: Salt solutions, reverse micelles, and lipid multi-bilayers  

SciTech Connect (OSTI)

Our goal is to understand the structure and dynamics of water, in its different phases, at the interfaces between these phases, and in confined and heterogeneous environments. To this end, linear and nonlinear vibrational spectroscopy is playing a very important role. We have developed techniques for calculating spectroscopic observables, and then used our results to analyze and interpret experiment.

Skinner, James

2013-11-05T23:59:59.000Z

203

In-situ Study of Dynamic Phenomena at Metal Nanosolder Interfaces Using Aberration Corrected Scanning Transmission Electron Microcopy.  

SciTech Connect (OSTI)

Controlling metallic nanoparticle (NP) interactions plays a vital role in the development of new joining techniques (nanosolder) that bond at lower processing temperatures but remain viable at higher temperatures. The pr imary objective of this project is t o develop a fundamental understanding of the actual reaction processes, associated atomic mechanisms, and the resulting microstructure that occur during thermally - driven bond formation concerning metal - metal nano - scale (<50nm) interfaces. In this LDRD pr oject, we have studied metallic NPs interaction at the elevated temperatures by combining in - situ transmission electron microscopy (TEM ) using an aberration - corrected scanning transmission electron microscope (AC - STEM) and atomic - scale modeling such as m olecular dynamic (MD) simulations. Various metallic NPs such as Ag, Cu and Au are synthesized by chemical routines. Numerous in - situ e xperiments were carried out with focus of the research on study of Ag - Cu system. For the first time, using in - situ STEM he ating experiments , we directly observed t he formation of a 3 - dimensional (3 - D) epitaxial Cu - Ag core - shell nanoparticle during the thermal interaction of Cu and Ag NPs at elevated temperatures (150 - 300 o C). The reaction takes place at temperatures as low as 150 o C and was only observed when care was taken to circumvent the effects of electron beam irradiation during STEM imaging. Atomic - scale modeling verified that the Cu - Ag core - shell structure is energetically favored, and indicated that this phenomenon is a nano - scale effect related to the large surface - to - volume ratio of the NPs. The observation potentially can be used for developing new nanosolder technology that uses Ag shell as the %22glue%22 that stic ks the particles of Cu together. The LDRD has led to several journal publications and numerous conference presentations, and a TA. In addition, we have developed new TEM characterization techniques and phase - field modeling tools that can be used for future materials research at Sandia. Acknowledgeme nts This work was supported by the Laboratory Directed Research and Development (LDRD) program of Sandia National Laboratories. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidia ry of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

Lu, Ping

2014-10-01T23:59:59.000Z

204

One-electron-transfer reactions of the couple SO/sub 2//SO/sub 2//sup -/ in aqueous solutions. Pulse radiolytic and cyclic voltametric studies  

SciTech Connect (OSTI)

Rate constants for one-electron reduction of SO/sub 2/ by several radicals and for reduction of several compounds by SO/sub 2//sup .-/ radicals were determined by pulse radiolysis at pH 1. SO/sub 2/ is reduced by the (CH/sub 3/)/sub 2/COH radicals with k = 2.1 x 10/sup 9/ M/sup -1/ s/sup -1/ and by viologen radicals and certain porphyrin ..pi..-radical anions with k approx. 10/sup 8/-10/sup 9/ M/sup -1/ s/sup -1/. The SO/sub 2//sup .-/ radical reduces compounds which have reduction potentials more positive than -0.28 V. The rate constants for these reductions vary from < 10/sup 7/ to > 10/sup 9/ M/sup -1/ s/sup -1/ and depend on the redox potentials of the compounds and on other properties such as charge and self-exchange rate. The reduction potentials for SO/sub 2/ and for the porphyrins were determined by cyclic voltametry under identical conditions. These reduction potentials were used along with the rate constants and previously reported self-exchange rates to estimate the self-exchange rate for the couple SO/sub 2//SO/sub 2//sup .-/ in acidic solutions. The calculated values were found to vary over many orders of magnitude, similar to the situation reported before for the O/sub 2//O/sub 2//sup -/ couple.

Neta, P.; Huie, R.E.; Harriman, A.

1987-03-12T23:59:59.000Z

205

SOLUTION-PROCESSED INORGANIC ELECTRONICS  

E-Print Network [OSTI]

Electrodes for Dye-Sensitized Solar Cells, Nano Letters,diodes (OLEDs), dye- sensitized solar cells, as well as

Bakhishev, Teymur

2011-01-01T23:59:59.000Z

206

Dynamics of pulled desorption with effects of excluded volume interaction: The p-Laplacian diffusion equation and its exact solution  

E-Print Network [OSTI]

We analyze the dynamics of desorption of a polymer molecule which is pulled at one of its ends with force $f$, trying to desorb it. We assume a monomer to desorb when the pulling force on it exceeds a critical value $f_{c}$. We formulate an equation for the average position of the $n^{th}$ monomer, which takes into account excluded volume interaction through the blob-picture of a polymer under external constraints. The approach leads to a diffusion equation with a $p$-Laplacian for the propagation of the stretching along the chain. This has to be solved subject to a moving boundary condition. Interestingly, within this approach, the problem can be solved exactly in the trumpet, stem-flower and stem regimes. In the trumpet regime, we get $\\tau=\\tau_{0}n_d^{2}$ where $n_d$ is the number of monomers that have desorbed at the time $\\tau$. $\\tau_{0}$ is known only numerically, but for $f$ close to $f_{c}$, it is found to be $\\tau_{0}\\sim f_c/(f^{2/3}-f_{c}^{2/3})$. If one used simple Rouse dynamics, this result changes to {\

K. L. Sebastian; V. G. Rostiashvili; T. A. Vilgis

2011-08-31T23:59:59.000Z

207

Electron acoustic wave driven vortices with non-Maxwellian hot electrons in magnetoplasmas  

SciTech Connect (OSTI)

Linear dispersion characteristics of the Electron Acoustic Wave (EAW) and the corresponding vortex structures are investigated in a magnetoplasma in the presence of non-Maxwellian hot electrons. In this regard, kappa and Cairns distributed hot electrons are considered. It is noticed that the nonthermal distributions affect the phase velocity of the EAW. Further, it is found that the phase velocity of EAW increases for Cairns and decreases for kappa distributed hot electrons. Nonlinear solutions in the form of dipolar vortices are also obtained for both stationary and non-stationary ions in the presence of kappa distributed hot electrons and dynamic cold electrons. It is found that the amplitude of the nonlinear vortex structures also reduces with kappa factor like the electron acoustic solitons.

Haque, Q. [Theoretical Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); National Center for Physics Shahdrah Valley Road, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Zakir, U. [Institute of Physics and Electronics, University of Peshawar, and Khyber Pakhtun Khwa 25000 (Pakistan); Department of Physics, University of Malakand Chakdara Dir(L), Khyber Pakhtun Khwa 18800 Pakistan (Pakistan)

2014-07-15T23:59:59.000Z

208

Urea-Functionalized M4L6 Cage Receptors: Self-Assembly, Dynamics, and Anion Recognition in Aqueous Solutions  

SciTech Connect (OSTI)

We present an extensive study of a novel class of de novo designed tetrahedral M{sub 4}L{sub 6} (M = Ni, Zn) cage receptors, wherein internal decoration of the cage cavities with urea anion-binding groups, via functionalization of the organic components L, led to selective encapsulation of tetrahedral oxoanions EO{sub 4}{sup -} (E = S, Se, Cr, Mo, W, n = 2; E = P, n = 3) from aqueous solutions, based on shape, size, and charge recognition. External functionalization with tBu groups led to enhanced solubility of the cages in aqueous methanol solutions, thereby allowing for their thorough characterization by multinuclear ({sup 1}H, {sup 13}C, {sup 77}Se) and diffusion NMR spectroscopies. Additional experimental characterization by electrospray ionization mass spectrometry, UV-vis spectroscopy, and single-crystal X-ray diffraction, as well as theoretical calculations, led to a detailed understanding of the cage structures, self-assembly, and anion encapsulation. We found that the cage self-assembly is templated by EO{sub 4}{sup -} oxoanions (n {ge} 2), and upon removal of the templating anion the tetrahedral M{sub 4}L{sub 6} cages rearrange into different coordination assemblies. The exchange selectivity among EO{sub 4}{sup -} oxoanions has been investigated with {sup 77}Se NMR spectroscopy using {sup 77}SeO{sub 4}{sup 2-} as an anionic probe, which found the following selectivity trend: PO{sub 4}{sup 3-} CrO{sub 4}{sup 2-} > SO{sub 4}{sup 2-} > SeO{sub 4}{sup 2-} > MoO{sub 4}{sup 2-} > WO{sub 4}{sup 2-}. In addition to the complementarity and flexibility of the cage receptor, a combination of factors have been found to contribute to the observed anion selectivity, including the anions charge, size, hydration, basicity, and hydrogen-bond acceptor abilities.

Custelcean, Radu [ORNL; Bonnesen, Peter V [ORNL; Duncan, Nathan C [ORNL; Van Berkel, Gary J [ORNL; Hay, Benjamin [ORNL

2012-01-01T23:59:59.000Z

209

Femtosecond-picosecond laser photolysis studies on the dynamics of excited charge-transfer complexes: Aromatic hydrocarbon-acid anhydride, -tetracyanoethylene, and -tetracyanoquinodimethane systems in acetonitrile solutions  

SciTech Connect (OSTI)

Formation processes of contact ion pairs (CIP) from the excited Franck-Condon (FC) state of charge-transfer (CT) complexes of aromatic hydrocarbons with acid anhydride as well as cyano compound acceptors in acetonitrile solution and charge recombination (CR) rates (k{sub CR}{sup CIP}) of produced CIP states have been investigated by femtosecond and picosecond laser phototlysis and time-resolved absorption spectral measurements covering a wide range of free energy gap-{Delta}G{degree}{sub ip} between the ion pair and the ground state. It has been confirmed that the CIP formation becomes faster and k{sub CR}{sup CIP} of the produced CIP increases with increase of the strengths of the electron donor (D) and acceptor (A) in the complex, i.e., with decrease of the {minus}{Delta}G{degree}{sub ip} value. This peculiar energy gap dependence of k{sub CR}{sup CIP}, quite different from the bell-shaped one observed in the case of the solvent-separated ion pairs (SSIP) or loose ion pairs (LIP) formed by encounter between fluorescer and quencher in the fluoresence quenching reaction, has been interpreted by assuming the change of electronic and geometrical structures of CIP depending on the strengths of D and A.

Asahi, Tsuyoshi; Mataga, Noboru (Osaka Univ. (Japan))

1991-03-07T23:59:59.000Z

210

Ion-pairing dynamics of Li{sup +} and SCN{sup -} in dimethylformamide solution: Chemical exchange two-dimensional infrared spectroscopy  

SciTech Connect (OSTI)

Ultrafast two-dimensional infrared (2DIR) spectroscopy has been proven to be an exceptionally useful method to study chemical exchange processes between different vibrational chromophores under thermal equilibria. Here, we present experimental results on the thermal equilibrium ion pairing dynamics of Li{sup +} and SCN{sup -} ions in N,N-dimethylformamide. Li{sup +} and SCN{sup -} ions can form a contact ion pair (CIP). Varying the relative concentration of Li{sup +} in solution, we could control the equilibrium CIP and free SCN{sup -} concentrations. Since the CN stretch frequency of Li-SCN CIP is blue-shifted by about 16 cm{sup -1} from that of free SCN{sup -} ion, the CN stretch IR spectrum is a doublet. The temperature-dependent IR absorption spectra reveal that the CIP formation is an endothermic (0.57 kJ/mol) process and the CIP state has larger entropy by 3.12 J/(K mol) than the free ion states. Since the two ionic configurations are spectrally distinguishable, this salt solution is ideally suited for nonlinear IR spectroscopic investigations to study ion pair association and dissociation dynamics. Using polarization-controlled IR pump-probe methods, we first measured the lifetimes and orientational relaxation times of these two forms of ionic configurations. The vibrational population relaxation times of both the free ion and CIP are about 32 ps. However, the orientational relaxation time of the CIP, which is {approx}47 ps, is significantly longer than that of the free SCN{sup -}, which is {approx}7.7 ps. This clearly indicates that the effective moment of inertia of the CIP is much larger than that of the free SCN{sup -}. Then, using chemical exchange 2DIR spectroscopy and analyzing the diagonal peak and cross-peak amplitude changes with increasing the waiting time, we determined the contact ion pair association and dissociation time constants that are found to be 165 and 190 ps, respectively. The results presented and discussed in this paper are believed to be important, not only because the ion-pairing dynamics is one of the most fundamental physical chemistry problems but also because such molecular ion-ion interactions are of critical importance in understanding Hofmeister effects on protein stability.

Lee, Kyung-Koo; Park, Kwang-Hee; Kwon, Donghyun; Choi, Jun-Ho; Son, Hyewon [Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul 136-701 (Korea, Republic of); Park, Sungnam; Cho, Minhaeng [Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul 136-701 (Korea, Republic of); Multidimensional Spectroscopy Laboratory, Korea Basic Science Institute, Seoul 136-713 (Korea, Republic of)

2011-02-14T23:59:59.000Z

211

A parallel multistate framework for atomistic non-equilibrium reaction dynamics of solutes in strongly interacting organic solvents  

E-Print Network [OSTI]

We describe a parallel linear-scaling computational framework developed to implement arbitrarily large multi-state empirical valence bond (MS-EVB) calculations within CHARMM. Forces are obtained using the Hellman-Feynmann relationship, giving continuous gradients, and excellent energy conservation. Utilizing multi-dimensional Gaussian coupling elements fit to CCSD(T)-F12 electronic structure theory, we built a 64-state MS-EVB model designed to study the F + CD3CN -> DF + CD2CN reaction in CD3CN solvent. This approach allows us to build a reactive potential energy surface (PES) whose balanced accuracy and efficiency considerably surpass what we could achieve otherwise. We use our PES to run MD simulations, and examine a range of transient observables which follow in the wake of reaction, including transient spectra of the DF vibrational band, time dependent profiles of vibrationally excited DF in CD3CN solvent, and relaxation rates for energy flow from DF into the solvent, all of which agree well with experime...

Glowacki, David R; Harvey, Jeremy N

2014-01-01T23:59:59.000Z

212

Using X-ray free-electron lasers for probing of complex interaction dynamics of ultra-intense lasers with solid matter  

SciTech Connect (OSTI)

We demonstrate the potential of X-ray free-electron lasers (XFEL) to advance the understanding of complex plasma dynamics by allowing for the first time nanometer and femtosecond resolution at the same time in plasma diagnostics. Plasma phenomena on such short timescales are of high relevance for many fields of physics, in particular in the ultra-intense ultra-short laser interaction with matter. Highly relevant yet only partially understood phenomena become directly accessible in experiment. These include relativistic laser absorption at solid targets, creation of energetic electrons and electron transport in warm dense matter, including the seeding and development of surface and beam instabilities, ambipolar expansion, shock formation, and dynamics at the surfaces or at buried layers. In this paper, we focus on XFEL plasma probing for high power laser matter interactions based on quantitative calculations using synthesized data and evaluate the feasibility of various imaging and scattering techniques with special focus on the small angle X-ray scattering technique.

Kluge, T., E-mail: t.kluge@hzdr.de; Huang, L. G.; Metzkes, J.; Bussmann, M. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany)] [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Gutt, C. [Universitt Siegen, D-57068 Siegen (Germany)] [Universitt Siegen, D-57068 Siegen (Germany); Schramm, U.; Cowan, T. E. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany) [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Technische Universitt Dresden, D-01062 Dresden (Germany)

2014-03-15T23:59:59.000Z

213

THE JOURNAL OF CHEMICAL PHYSICS 134, 074107 (2011) Multistage ab initio quantum wavepacket dynamics for electronic structure  

E-Print Network [OSTI]

American Institute of Physics. [doi:10.1063/1.3534797] I. INTRODUCTION Electron transport between donor redox systems,1,2 where electron transport through an intervening bridge is central to photosynthesis,3 systems6­16 and solar energy conversion and storage.55­57 The intensity of current research effort

Iyengar, Srinivasan S.

214

Long-time electron spin storage via dynamical suppression of hyperfine-induced decoherence in a quantum dot  

E-Print Network [OSTI]

by the nuclear spin environment in a quantum dot can be substantially increased by subjecting the electron and characterized. The impact of system and control nonidealities is also assessed, including the effect.125336 PACS number s : 03.67.Pp, 03.65.Yz, 75.10.Jm, 02.60.Cb I. INTRODUCTION Electron and nuclear spin

215

A time-dependent momentum-space density functional theoretical approach for electron transport dynamics in molecular devices  

E-Print Network [OSTI]

We propose a time-dependent density functional theoretical (TDDFT) approach in momentum (\\mathcal{P} ) space for the study of electron transport in molecular devices under arbitrary biases. The basic equation of motion, which is a time...

Chu, Shih-I; Zhou, Zhongyuan

2009-10-27T23:59:59.000Z

216

Investigation of relativistic intensity laser generated hot electron dynamics via copper K{sub ?} imaging and proton acceleration  

SciTech Connect (OSTI)

Simultaneous experimental measurements of copper K{sub ?} imaging and the maximum target normal sheath acceleration proton energies from the rear target surface are compared for various target thicknesses. For the T-cubed laser (?4 J, 400 fs) at an intensity of ?2 10{sup 19} W cm{sup ?2}, the hot electron divergence is determined to be ?{sub HWHM}?22{sup } using a K{sub ?} imaging diagnostic. The maximum proton energies are measured to follow the expected reduction with increasing target thickness. Numerical modeling produces copper K{sub ?} trends for both signal level and electron beam divergence that are in good agreement with the experiment. A geometric model describing the electron beam divergence reproduces the maximum proton energy trends observed from the experiment and the fast electron density and the peak electric field observed in the numerical modeling.

Willingale, L.; Thomas, A. G. R.; Maksimchuk, A; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109 (United States)] [Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109 (United States); Morace, A. [University of California-San Diego, La Jolla, California 92093 (United States) [University of California-San Diego, La Jolla, California 92093 (United States); Universit di Milano-Biocca, Piazza della Scienza 3, 20126 Milano (Italy); Bartal, T.; Kim, J.; Beg, F. N. [University of California-San Diego, La Jolla, California 92093 (United States)] [University of California-San Diego, La Jolla, California 92093 (United States); Stephens, R. B.; Wei, M. S. [General Atomics, San Diego, California 92121 (United States)] [General Atomics, San Diego, California 92121 (United States)

2013-12-15T23:59:59.000Z

217

"Field-shell" of the self-interacting quantum electron  

E-Print Network [OSTI]

Self-interacting dynamics of non-local Dirac's electron has been proposed. This dynamics was revealed by the projective representation of operators corresponding to spin/charge degrees of freedom. Energy-momentum field is described by the system of quasi-linear ``field-shell" PDE's following from the conservation law expressed by the affine parallel transport in $CP(3)$ \\cite{Le1}. We discuss here solutions of these equations in the connection with the following problems: curvature of $CP(3)$ as a potential source of electromagnetic fields and the self-consistent problem of the electron mass.

Peter Leifer; Taha Massalha

2010-08-23T23:59:59.000Z

218

Electronic structure, molecular orientation, charge transfer dynamics and solar cells performance in donor/acceptor copolymers and fullerene: Experimental and theoretical approaches  

SciTech Connect (OSTI)

By combining experimental and theoretical approaches, the electronic structure, molecular orientation, charge transfer dynamics and solar cell performance in donor/acceptor copolymer poly[2,7-(9,9-bis(2-ethylhexyl)-dibenzosilole)-alt-4,7-bis(thiophen-2-yl) benzo-2,1,3-thiadiazole] (PSiF-DBT) films and blended with 6,6.-phenyl-C 61-butyric acid methyl ester (PSiF-DBT:PCBM) were investigated. Good agreement between experimental and theoretical PSiF-DBT UV-Vis absorption spectrum is observed and the main molecular orbitals contributing to the spectrum were determined using DFT single point calculations. Non-coplanar configuration was determined by geometric optimization calculation in isolated PSiF-DBT pentamer and corroborated by angular variation of the sulphur 1s near-edge X-ray absorption fine structure (NEXAFS) spectra. Edge-on and plane-on molecular orientations were obtained for thiophene and benzothiadiazole units, respectively. A power conversion efficiency up to 1.58%, open circuit voltage of 0.51 V, short circuit current of 8.71 mA/cm{sup 2} and a fill factor of 35% was obtained using blended PSiF-DBT:PCBM as active layer in a bulk heterojunction solar cell. Ultrafast electron dynamics in the low-femtosecond regime was evaluated by resonant Auger spectroscopy using the core-hole clock methodology around sulphur 1s absorption edge. Electron delocalization times for PSiF-DBT and PSiF-DBT:PCBM polymeric films were derived for selected excitation energies corresponding to the main transitions in the sulphur 1s NEXAFS spectra. The mixture of PSiF-DBT with PCBM improves the charge transfer process involving the ?* molecular orbital of the thiophene units.

Garcia-Basabe, Y.; Borges, B. G. A. L.; Rocco, M. L. M., E-mail: lsroman@fisica.ufpr.br, E-mail: luiza@iq.ufrj.br [Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro 21941-909 (Brazil); Marchiori, C. F. N.; Yamamoto, N. A. D.; Koehler, M.; Roman, L. S., E-mail: lsroman@fisica.ufpr.br, E-mail: luiza@iq.ufrj.br [Departament of Physics, Federal University of Paran, Curitiba 81531-990 (Brazil); Macedo, A. G. [Departament of Physics, Technological Federal University of Paran, Curitiba 80230-901 (Brazil)

2014-04-07T23:59:59.000Z

219

Strong Electronic Polarization of the C60 Fullerene by the Imidazolium-Based Ionic Liquids: Accurate Insights from Born-Oppenheimer Molecular Dynamics Simulations  

E-Print Network [OSTI]

Fullerenes are known to be polarizable due to the strained carbon-carbon bonds and high surface curvature. Electronic polarization of fullerenes is of steady practical importance, since it leads to non-additive interactions and, therefore, to unexpected phenomena. For the first time, hybrid density functional theory (HDFT) powered Born-Oppenheimer molecular dynamics (BOMD) simulations have been conducted to observe electronic polarization and charge transfer phenomena in the C60 fullerene at finite temperature (350 K). The non-additive phenomena are fostered by the three selected imidazolium-based room-temperature ionic liquids (RTILs). We conclude that although charge transfer appears nearly negligible in these systems, an electronic polarization is indeed significant leading to a systematically positive effective electrostatic charge on the C60 fullerene: +0.14e in [EMIM][Cl], +0.21e in [EMIM][NO3], +0.17e in [EMIM][PF6]. These results are, to certain extent, unexpected providing an inspiration to consider ...

Chaban, Vitaly V

2015-01-01T23:59:59.000Z

220

Introduction to Structure and Dynamics: Inaugural Issue  

E-Print Network [OSTI]

the premier issue of Structure and Dynamics, an electronicFor this great boon, Structure and Dynamics in particular iselectronic journals, Structure and Dynamics will be widely

White, Douglas R.; Manlove, Robert; Colby, B. N.; Garfias, Robert; Bell, Duran

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic electron solutions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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221

Dynamic Phase Shifts in Nanoscale Distance Measurements by Double...  

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

by Double Electron Electron Resonance (DEER) . Abstract: The off-resonant pump pulse used in double electron electron resonance (DEER) measurements produces dynamic...

222

Theory of dynamic nuclear polarization and feedback in quantum dots  

E-Print Network [OSTI]

An electron confined in a quantum dot interacts with its local nuclear spin environment through the hyperfine contact interaction. This interaction combined with external control and relaxation or measurement of the electron spin allows for the generation of dynamic nuclear polarization. The quantum nature of the nuclear bath, along with the interplay of coherent external fields and incoherent dynamics in these systems renders a wealth of intriguing phenomena seen in recent experiments such as electron Zeeman frequency focusing, hysteresis, and line dragging. We develop in detail a fully quantum, self-consistent theory that can be applied to such experiments and that moreover has predictive power. Our theory uses the operator sum representation formalism in order to incorporate the incoherent dynamics caused by the additional, Markovian bath, which in self-assembled dots is the vacuum field responsible for electron-hole optical recombination. The beauty of this formalism is that it reduces the complexity of the problem by encoding the joint dynamics of the external coherent and incoherent driving in an effective dynamical map that only acts on the electron spin subspace. This together with the separation of timescales in the problem allows for a tractable and analytically solvable formalism. The key role of entanglement between the electron spin and the nuclear spins in the formation of dynamic nuclear polarization naturally follows from our solution. We demonstrate the theory in detail for an optical pulsed experiment and present an in-depth discussion and physical explanation of our results.

Sophia E. Economou; Edwin Barnes

2014-04-06T23:59:59.000Z

223

Studies in Nonlinear Dynamics & Econometrics  

E-Print Network [OSTI]

Studies in Nonlinear Dynamics & Econometrics Volume 8, Issue 3 2004 Article 1 The Long Memory in Nonlinear Dynamics & Econometrics is produced by The Berkeley Electronic Press (bepress). http

224

Electron transfer through a lipid-bilayer-membrane-aqueous-solution interface and kinetics of the oxidation of viologen radicals in homogeneous and vesicular systems  

SciTech Connect (OSTI)

The purpose of the present work was to study the influence of the nature of the oxidizing agent on the rate constant of the oxidation of viologen radicals in homogeneous and vesicular systems by water-soluble oxidizing agents. In this work the authors used the following water-soluble viologens: methyl viologen, sulfoethyl viologen, trimethylaminopropyl viologen, and octadecyl viologen, which is soluble only in a lipid bilayer. The rate constant for the oxidation of a viologen radical cation in a lipid bilayer by electron acceptors in the aqueous phase, in contrast to the homogeneous reaction, is lower than the rate constant of the diffusion-controlled reaction. The rate of electron transfer on the interface is determined by the interaction of the reactants with the lipid bilayer. The rate constant for electron transfer from a viologen radical cation near the inner surface of a lipid bilayer to viologen near the outer surface with the formation of a radical which is available for oxidation in the external aqueous phase has been determined and has been found to be independent of the nature of the oxidizing agent.

Shafirovich, V.Ya.; Levin, P.P.; Khannanov, N.K.; Kuz'min, V.A.

1986-10-10T23:59:59.000Z

225

Coordination and Hydrolysis of Plutonium Ions in Aqueous Solution...  

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

Hydrolysis of Plutonium Ions in Aqueous Solution using Car-Parrinello Molecular Dynamics Free Energy Coordination and Hydrolysis of Plutonium Ions in Aqueous Solution using...

226

Probing the Degradation Mechanisms in Electrolyte Solutions for...  

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

Degradation Mechanisms in Electrolyte Solutions for Li-ion Batteries by In-Situ Transmission Electron Microscopy. Probing the Degradation Mechanisms in Electrolyte Solutions for...

227

A high dynamic range data acquisition system for a solid-state electron Electric Dipole Moment experiment  

E-Print Network [OSTI]

We have built a high precision (24-bit) data acquisition (DAQ) system with eight simultaneously sampling input channels for the measurement of the electric dipole moment (EDM) of the electron. The DAQ system consists of two main components, a master board and eight individual analog-to-digital converter (ADC) boards. This custom DAQ system provides galvanic isolation, with fiber optic communication, between the master board and each ADC board to reduce the possibility of ground loop pickups. In addition, each ADC board is enclosed in its own heavy-duty radio frequency shielding enclosure and powered by DC batteries, to attain the ultimate low levels of channel cross-talk. In this paper, we describe the implementation of the DAQ system and scrutinize its performance.

Young Jin Kim; Brandon Kunkler; Chen-Yu Liu; Gerard Visser

2011-06-07T23:59:59.000Z

228

Quasilinear dynamics of a cloud of hot electrons propagating through a plasma with decreasing density and temperature  

SciTech Connect (OSTI)

The effects of plasma inhomogeneities on the propagation of a cloud of hot electrons through a cold background plasma and generation of Langmuir waves are investigated using numerical simulations of the quasilinear equations. It is found that in a plasma with decreasing density the quasilinear relaxation of the electron distribution in velocity space is accelerated and the levels of the generated Langmuir waves are enhanced. The magnitude of the induced emission rate is increased and its maximum value moves to lower velocities. Due to density gradient the height of plateau shows an increase at small distances and a corresponding decrease at large distances. It is also found that in a plasma with decreasing temperature, the relaxation of the beam is retarded, the spectral density of Langmuir waves is broadened, and the height of the plateau decreases below its value in a uniform plasma. In the presence of both density and temperature gradients, at given position, the height and upper boundary of the plateau and the level of Langmuir waves are all increased at small velocities. The spatial expansion of the beam is increased by the plasma inhomogeneities, but its average velocity of propagation decreases. Initially, at a given position, the velocity at the upper boundary of the plateau is smaller in the presence of the density gradient than in the uniform plasma but the reverse is true at longer times. Due to temperature gradient, at large times and small distances, the upper boundary of the plateau is increased above its value in the uniform plasma. Because of fast relaxation, the value of the lower boundary of the plateau in the plasma with decreasing density is always less than its value in the uniform plasma. It is found that the local velocity of the beam decreases when the density gradient is present. The local velocity spread of the beam remains unchanged during the propagation of the beam in the uniform plasma, but increases in the presence of inhomogeneities.

Foroutan, G. [Department of Physics, Faculty of Science, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); School of Physics, The University of Sydney, Sydney NSW 2006 (Australia); Khalilpour, H.; Moslehi-Fard, M. [Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of); Li, B.; Robinson, P. A. [School of Physics, University of Sydney, Sydney NSW 2006 (Australia)

2008-12-15T23:59:59.000Z

229

Heat Transfer Study of Polymer Solutions with Different Rigidities  

E-Print Network [OSTI]

rigidities. A mathematic method was introduced to model the rigidity of polymer chain's effect on the dynamic viscosity of dilute polymer solution. Results were also obtained for the dilute polymer solutions under both hydro-dynamically developing and hydro...

Huang, Yao

2014-05-08T23:59:59.000Z

230

Quasilinear dynamics of a cloud of hot electrons propagating through a plasma in the presence of an externally applied uniform electric field  

SciTech Connect (OSTI)

The propagation of a cloud of hot electrons through a plasma and the generation of Langmuir waves are investigated in the presence of an externally applied uniform electric field. Using numerical simulations of the quasilinear equations the evolution of the electron distribution function and the spectral density of Langmuir waves are monitored in coordinate and velocity space. It is found that the Langmuir waves are enhanced in the presence of the electric field and the distribution functions of the beam and Langmuir waves diffuse toward large velocities. The overall self-similar characteristic of the system is preserved in the presence of the electric field. The average beam velocity is no longer constant and increases with time along its trajectory, but the acceleration is much less than that of free streaming particles. The beam number density plateaus in coordinate space and large scale, small amplitude fluctuations develop on the top of this plateau. The level of the fluctuations depends on the strength of the electric field. We also investigated the influence of the external electric field on the evolution of gas-dynamical parameters such as the height of the plateau in the beam distribution function in velocity space, its upper velocity boundary, and the local velocity spread of the beam. Due to the finite quasilinear relaxation time and spatial inhomogeneity of the electron beam, different parts of the beam are in different states of relaxation. In the region of partial relaxation the plateau is specified by both upper and lower velocity boundaries. The upper boundary of plateau increases linearly with the strength of the electric field but the lower boundary is independent of it. Contrary to the free streaming of a beam in an electric field or quasilinear relaxation in the absence of the electric field, the local velocity spread of the beam increases during its propagation. Some of the electrons at the back of the beam are also transferred by the electric field to its front, so that the height of plateau increases at large distan0009c.

Foroutan, G.; Robinson, P. A.; Zahed, H.; Li, B.; Cairns, I. H. [Physics Department, Faculty of Science, Sahand University of Technology, 51335-1996, Tabriz, Iran and School of Physics, University of Sydney, NSW 2006, Sydney (Australia); School of Physics, University of Sydney, NSW 2006, Sydney (Australia); Physics Department, Faculty of Science, Sahand University of Technology, 51335-1996, Tabriz (Iran, Islamic Republic of); School of Physics, University of Sydney, NSW 2006, Sydney (Australia)

2007-12-15T23:59:59.000Z

231

Fourier transform electron paramagnetic resonance study of the photoreduction of anthraquinone with 4-methyl-2,6-di-tert-butylphenol in alcoholic solutions  

SciTech Connect (OSTI)

Using FT-EPR following laser excitation, the primary photochemical process in the photoreduction of anthraquinone with 4-methyl-2,6-di-tert-butylphenol was investigated. High-resolved spin-polarized EPR spectra taken with nanosecond time resolution gave unambiguous evidence for a two-step hydrogen abstraction reaction, consisting of a primary electron transfer followed by proton abstraction with a time delay, which allows for a noticeable escape probability of the initially generated anthrasemiquinone radical anion (AQ{sup {sm_bullet}minus}). The time dependence of the EPR intensities of the neutral 10-hydroxy-anthroxyl radical (AQH{sup {sm_bullet}}) as well as of AQ{sup {sm_bullet}} could be simulated for the full experimentally accessible time interval of 10 ns to 100 {mu}s. The kinetic model used invokes optical spin polarization, spin-lattice relaxation, radical generation, and AQH{sup {sm_bullet}}AQ interconversion. In addition, from an analysis of the highly-resolved FT-EPR spectra a complete set of AQH{sup {sm_bullet}} hyperfine splitting (hfs) constants could be measured in two different alcohols for the first time. 30 refs., 4 figs., 2 tabs.

Plueschau, M.; Kroll, G. [Universitaet Dortmund (Germany); Dinse, K.P. [TH Darmstadt (Germany)] [and others

1992-10-29T23:59:59.000Z

232

Massively-parallel electron dynamics calculations in real-time and real-space: Toward applications to nanostructures of more than ten-nanometers in size  

SciTech Connect (OSTI)

A highly efficient program of massively parallel calculations for electron dynamics has been developed in an effort to apply the method to optical response of nanostructures of more than ten-nanometers in size. The approach is based on time-dependent density functional theory calculations in real-time and real-space. The computational code is implemented by using simple algorithms with a finite-difference method in space derivative and Taylor expansion in time-propagation. Since the computational program is free from the algorithms of eigenvalue problems and fast-Fourier-transformation, which are usually implemented in conventional quantum chemistry or band structure calculations, it is highly suitable for massively parallel calculations. Benchmark calculations using the K computer at RIKEN demonstrate that the parallel efficiency of the program is very high on more than 60?000 CPU cores. The method is applied to optical response of arrays of C{sub 60} orderly nanostructures of more than 10 nm in size. The computed absorption spectrum is in good agreement with the experimental observation.

Noda, Masashi; Ishimura, Kazuya; Nobusada, Katsuyuki [Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585 (Japan); Yabana, Kazuhiro; Boku, Taisuke [Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan)

2014-05-15T23:59:59.000Z

233

Spin and charge dynamics of the two-dimensional {ital t}-{ital J} model at intermediate electron densities: Absence of spin-charge separation  

SciTech Connect (OSTI)

We present an exact diagonalization study of the dynamical spin and density correlation functions in small clusters of the {ital t}-{ital J} model, focusing on the regime of intermediate and low electron densities, {rho}{sub {ital e}}{lt}0.5. In two dimensions (2D) both correlation functions agree remarkably well with the convolution of the single-particle spectral function, i.e., the simplest estimate possible within a Fermi-liquid picture. Deviations from the convolution are shown to originate from symmetry-related selection rules, which are unaccounted for in the convolution estimate. For all fillngs under consideration, we show that the low-energy peaks originate from particle-hole excitations between the Fermi momenta, as expected for a Fermi liquid. We contrast this with the behavior in 1D, where spin and density correlation function show the differences characteristic of spin-charge separation and where neither correlation function is approximated well by the convolution.

Eder, R.; Ohta, Y. [Department of Applied Physics, Nagoya University, Nagoya 464-01 (Japan)] [Department of Applied Physics, Nagoya University, Nagoya 464-01 (Japan)

1995-05-01T23:59:59.000Z

234

Use of Ultrafast Dispersed Pump-Dump-Probe and Pump-Repump-Probe Spectroscopies to Explore the Light-Induced Dynamics of Peridinin in Solution  

E-Print Network [OSTI]

Use of Ultrafast Dispersed Pump-Dump-Probe and Pump-Repump-Probe Spectroscopies to Explore Form: NoVember 14, 2005 Optical pump-induced dynamics of the highly asymmetric carotenoid peridinin in methanol was studied by dispersed pump-probe, pump-dump-probe, and pump-repump-probe transient absorption

van Stokkum, Ivo

235

A Near-Infrared Transient Absorption Study of the Excited-State Dynamics of the Carotenoid Spirilloxanthin in Solution and in the LH1 Complex of Rhodospirillum rubrum  

E-Print Network [OSTI]

A Near-Infrared Transient Absorption Study of the Excited-State Dynamics of the Carotenoid rubrum were studied by near-infrared ultrafast transient absorption spectroscopy. Global analysis), does not exhibit detectable spectral features in the near-infrared region. Introduction The excited

van Stokkum, Ivo

236

Density functional theory study of the structural, electronic, lattice dynamical, and thermodynamic properties of Li4SiO4 and its capability for CO2 capture  

SciTech Connect (OSTI)

The structural, electronic, lattice dynamical, optical, thermodynamic, and CO{sub 2} capture properties of monoclinic and triclinic phases of Li{sub 4}SiO{sub 4} are investigated by combining density functional theory with phonon lattice dynamics calculations. We found that these two phases have some similarities in their bulk and thermodynamic properties. The calculated bulk modulus and the cohesive energies of these two phases are close to each other. Although both of them are insulators, the monoclinic phase of Li{sub 4}SiO{sub 4} has a direct band gap of 5.24 eV while the triclinic Li{sub 4}SiO{sub 4} phase has an indirect band gap of 4.98 eV. In both phases of Li{sub 4}SiO{sub 4}, the s orbital of O mainly contributes to the lower-energy second valence band (VB{sub 2}) and the p orbitals contribute to the fist valence band (VB{sub 1}) and the conduction bands (CBs). The s orbital of Si mainly contributes to the lower portions of the VB1 and VB{sub 2}, and Si p orbitals mainly contribute to the higher portions of the VB{sub 1} and VB{sub 2}. The s and p orbitals of Li contribute to both VBs and to CBs, and Li p orbitals have a higher contribution than the Li s orbital. There is possibly a phonon soft mode existing in triclinic {gamma}-Li{sub 4}SiO{sub 4}; in the monoclinic Li{sub 4}SiO{sub 4}, there are three phonon soft modes, which correspond to the one type of Li disordered over a few sites. Their LO-TO splitting indicates that both phases of Li{sub 4}SiO{sub 4} are polar anisotropic materials. The calculated infrared absorption spectra for LO and TO modes are different for these two phases of Li{sub 4}SiO{sub 4}. The calculated relationships of the chemical potential versus temperature and CO{sub 2} pressure for reaction of Li{sub 4}SiO{sub 4} with CO{sub 2} shows that Li{sub 4}SiO{sub 4} could be a good candidate for a high-temperature CO{sub 2} sorbent while used for postcombustion capture technology.

Duan, Yuhua; Parlinski, K.

2011-01-01T23:59:59.000Z

237

Electronic, structural, phonon dynamical, and CO{sub 2} capture properties of LiMZrO{sub 3} (M=Na, K) by ab initio thermodynamic investigation  

SciTech Connect (OSTI)

The electronic, structural and phonon properties of LiMZrO{sub 3} (M=Na, K) were investigated by the density functional theory and lattice phonon dynamics. Their thermodynamic properties for CO{sub 2} absorption/desorption were analyzed in comparison with the corresponding M{sub 2}ZrO{sub 3}. Two substituted configurations of LiMZrO{sub 3} were created from Li{sub 2}ZrO{sub 3}. Both types of LiNaZrO3 have direct band gaps with values of 3.84 eV and 3.49 eV respectively. While in the case of LiKZrO{sub 3}, one type has an indirect band gap of 3.79 eV between ? and M high symmetric points while another has a direct band gap of 3.12 eV. The phonon dispersions and phonon density of states of LiMZrO{sub 3} were calculated with the direct method. From the calculated thermodynamic properties of LiMZrO{sub 3} reacting with CO{sub 2}, our results showed that by doping Na into Li{sub 2}ZrO{sub 3}, the obtained new solid LiNaZrO{sub 3} has better performance as a CO{sub 2} sorbent applying to post-combustion capture technology. For K doping into Li{sub 2}ZrO{sub 3}, our calculated thermodynamic results showed that the new solid LiKZrO{sub 3} does not gain improvement on its CO{sub 2} capture performance because its regeneration temperature is much higher than Li{sub 2}ZrO{sub 3}.

Duan, Yuhua

2014-01-01T23:59:59.000Z

238

Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution  

SciTech Connect (OSTI)

We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast white light supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.

Henn, T.; Kiessling, T., E-mail: tobias.kiessling@physik.uni-wuerzburg.de; Ossau, W.; Molenkamp, L. W. [Physikalisches Institut (EP3), Universitt Wrzburg, 97074 Wrzburg (Germany)] [Physikalisches Institut (EP3), Universitt Wrzburg, 97074 Wrzburg (Germany); Biermann, K.; Santos, P. V. [Paul-Drude-Institut fr Festkrperelektronik, 10117 Berlin (Germany)] [Paul-Drude-Institut fr Festkrperelektronik, 10117 Berlin (Germany)

2013-12-15T23:59:59.000Z

239

Efficient indium-tin-oxide free inverted organic solar cells based on aluminum-doped zinc oxide cathode and low-temperature aqueous solution processed zinc oxide electron extraction layer  

SciTech Connect (OSTI)

Indium-tin-oxide (ITO) free inverted organic solar cells (IOSCs) based on aluminum-doped zinc oxide (AZO) cathode, low-temperature aqueous solution processed zinc oxide (ZnO) electron extraction layer, and poly(3-hexylthiophene-2, 5-diyl):[6, 6]-phenyl C{sub 61} butyric acid methyl ester blend were realized in this work. The resulted IOSC with ZnO annealed at 150?C shows the superior power conversion efficiency (PCE) of 3.01%, if decreasing the ZnO annealing temperature to 100?C, the obtained IOSC also shows a PCE of 2.76%, and no light soaking issue is observed. It is found that this ZnO film not only acts as an effective buffer layer but also slightly improves the optical transmittance of AZO substrates. Further, despite the relatively inferior air-stability, these un-encapsulated AZO/ZnO IOSCs show comparable PCEs to the referenced ITO/ZnO IOSCs, which demonstrates that the AZO cathode is a potential alternative to ITO in IOSCs. Meanwhile, this simple ZnO process is compatible with large area deposition and plastic substrates, and is promising to be widely used in IOSCs and other relative fields.

Chen, Dazheng; Zhang, Chunfu, E-mail: cfzhang@xidian.edu.cn; Wang, Zhizhe; Zhang, Jincheng; Tang, Shi; Wei, Wei; Sun, Li; Hao, Yue, E-mail: yhao@xidian.edu.cn [State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, No. 2 South Taibai Road, Xi'an 710071 (China)

2014-06-16T23:59:59.000Z

240

Real-time quantum trajectories for classically allowed dynamics in strong laser fields  

E-Print Network [OSTI]

Both the physical picture of the dynamics of atoms and molecules in intense infrared fields and its theoretical description use the concept of electron trajectories. Here we address a key question which arises in this context: Are distinctly quantum features of these trajectories, such as the complex-valued coordinates, physically relevant in the classically allowed region of phase space, and what is their origin? First, we argue that solutions of classical equations of motion can account for quantum effects. To this end, we construct an exact solution to the classical Hamilton-Jacobi equation which accounts for dynamics of the wave packet, and show that this solution is physically correct in the limit $\\hbar \\to 0$. Second, we show that imaginary components of classical trajectories are directly linked to the finite size of the initial wavepacket in momentum space. This way, if the electronic wavepacket produced by optical tunneling in strong infrared fiels is localised both in coordinate and momentum, its m...

Plimak, L I

2015-01-01T23:59:59.000Z

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


241

A Review on Ab Initio Approaches for Multielectron Dynamics  

E-Print Network [OSTI]

In parallel with the evolution of femtosecond and attosecond laser as well as free-electron laser technology, a variety of theoretical methods have been developed to describe the behavior of atoms, molecules, clusters, and solids under the action of those laser pulses. Here we review major ab initio wave-function-based numerical approaches to simulate multielectron dynamics in atoms and molecules driven by intense long-wavelength and/or ultrashort short-wavelength laser pulses. Direct solution of the time-dependent Schr\\"odinger equation (TDSE), though its applicability is limited to He, ${\\rm H}_2$, and Li, can provide an exact description and has been greatly contributing to the understanding of dynamical electron-electron correlation. Multiconfiguration self-consistent-field (MCSCF) approach offers a flexible framework from which a variety of methods can be derived to treat both atoms and molecules, with possibility to systematically control the accuracy. The equations of motion of configuration interactio...

Ishikawa, Kenichi L

2015-01-01T23:59:59.000Z

242

Modification of Defect Structures in Graphene by Electron Irradiation...  

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

Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations. Modification of Defect Structures in Graphene by Electron...

243

Explicit Correlated Exciton-Vibrational Dynamics of the FMO Complex  

E-Print Network [OSTI]

The coupled exciton-vibrational dynamics of a 3-site FMO model is investigated using the numerically exact multilayer multiconfiguration time-dependent Hartree approach. Thereby the vibrational mode specific coupling to local electronic transitions is adapted from a discretized experimental spectral density. The solution of the resulting time-dependent Schr\\"odinger equation including three electronic and 450 vibrational degrees of freedom is analyzed in terms of excitonic populations and coherences. Emphasis is put onto the role of specific ranges of vibrational frequencies. It is observed that modes between 160 and 300 cm$^{-1}$ are responsible for the subpicosecond population and coherence decay.

Schulze, Jan

2015-01-01T23:59:59.000Z

244

Electron localization following attosecond molecular photoionization  

E-Print Network [OSTI]

- second pump­probe strategies as a powerful tool for investigating the complex molecular dynamics , their use in studying atomic photo- excitation and photoionization6,7 and electron dynamics in solids8 has and biomolecular complexes11,12 . Extremely fast molecular dynamics involving electron correlation can also

Kling, Matthias

245

Uranyl fluoride luminescence in acidic aqueous solutions  

SciTech Connect (OSTI)

Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 {+-} 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO{sub 4} at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO{sub 2}F{sub 2}. Studies on the effect of added LiNO{sub 3} or Na{sub 2}WO{sub 4}{center_dot}2H{sub 2}O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF{sub 6} content of WF{sub 6} gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF{sub 6}.

Beitz, J.V.; Williams, C.W. [Argonne National Lab., IL (United States). Chemistry Div.

1996-08-01T23:59:59.000Z

246

Correlated exciton dynamics in semiconductor nanostructures  

E-Print Network [OSTI]

The absorption and dissipation of energy in semiconductor nanostructures are often determined by excited electron dynamics. In semiconductors, one fundamentally important electronic state is an exciton, an excited electron ...

Wen, Patrick, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

247

A Radiation-Hard Dual Channel 4-bit Pipeline for a 12-bit 40 MS/s ADC Prototype with extended Dynamic Range for the ATLAS Liquid Argon Calorimeter Readout Electronics Upgrade at the CERN LHC  

E-Print Network [OSTI]

The design of a radiation-hard dual channel 12-bit 40 MS/s pipeline ADC with extended dynamic range is presented, for use in the readout electronics upgrade for the ATLAS Liquid Argon Calorimeters at the CERN Large Hadron Collider. The design consists of two pipeline A/D channels with four Multiplying Digital-to-Analog Converters with nominal 12-bit resolution each. The design, fabricated in the IBM 130 nm CMOS process, shows a performance of 68 dB SNDR at 18 MHz for a single channel at 40 MS/s while consuming 55 mW/channel from a 2.5 V supply, and exhibits no performance degradation after irradiation. Various gain selection algorithms to achieve the extended dynamic range are implemented and tested.

Jayanth Kuppambatti; Jaroslav Ban; Timothy Andeen; Peter Kinget; Gustaaf Brooijmans

2013-07-31T23:59:59.000Z

248

The electronic properties and lattice dynamics of (Na{sub 0.5}Bi{sub 0.5})TiO{sub 3}: From cubic to tetragonal and rhombohedral phases  

SciTech Connect (OSTI)

The structural, electronic and dynamical properties of the cubic, tetragonal and rhombohedral phases of a lead-free ferroelectrics, (Na{sub 0.5}Bi{sub 0.5})TiO{sub 3} (NBT), have been studied with a density functional formalism. The direct band gap is determined to be 2?3?eV for three phases, suggesting them to be good optical material. The equilibrium structures were given, and the importance of Bi atom in the low-symmetry ferroelectric phases were investigated with the electron localization functions analysis. The vibration modes at the ? point were calculated to provide a basis for analyzing the Raman and IR spectra. Soft modes were found in both the cubic and the tetragonal phases, providing a clue in understanding the ferroelectric phase transition in NBT.

L, Hongfeng [Department of Applied Physics, College of Science, China Agricultural University, Beijing 100083 (China); Wang, Shanying [Department of Physics, Tsinghua University, Beijing 100084 (China); Wang, Xiaosu, E-mail: xiaosuwang@cau.edu.cn [Department of Applied Physics, College of Science, China Agricultural University, Beijing 100083 (China); Department of Physics, Tsinghua University, Beijing 100084 (China)

2014-03-28T23:59:59.000Z

249

Observation of Materials Processes in Liquids in the Electron Microscope  

SciTech Connect (OSTI)

Materials synthesis and the functioning of devices often indispensably involve liquid media. But direct visualization of dynamic process in liquids, especially with high spatial and temporal resolution, has been challenging. For solid materials, advances in aberration corrected electron microscopy have made observation of atomic level features a routine practice. Here we discuss the extent to which one can take advantage of the resolution of modern electron microscopes to image phenomenon occuring in liquids. We will describe the fundamentals of two different experimental approaches, closed and open liquid cells. We will illustrate the capabilities of each approach by considering processes in batteries and nucleation and growth of nanoparticles from solution. We conclude that liquid cell electron microscopy appears to be duly fulfilling its role for in situ studies of nanoscale processes in liquids, revealing physical and chemical processes otherwise difficult to observe.

Wang, Chong M.; Liao, Honggang; Ross, Frances M.

2015-01-01T23:59:59.000Z

250

Time-dependent density-functional theory for molecular processes in strong fields: Study of multiphoton processes and dynamical response of individual valence electrons of N2 in intense laser fields  

E-Print Network [OSTI]

in the exchange ~x!- only limit. In the latter approach @1#, theTime-dependent density-functional theor Study of multiphoton processes and dynam of N2 in inten Xi Chu and Department of Chemistry, University of Kansas, and Kansas Ce ~Received 30 July 2001; pu We...-I CHU PHYSICAL REVIEW A 64 0634041sg 21su 22sg 22su 21pu 43sg 2 . According to the valence bond theory, this molecule has a triple bond formed with 3sg and 1pu electrons. The 3sg orbital is parallel to the internuclear axis and the two degen- erate 1pu...

Chu, Xi; Chu, Shih-I

2001-11-14T23:59:59.000Z

251

Parallel Solutions of Partial Differential Equations with Adaptive Multigrid Methods  

E-Print Network [OSTI]

Parallel Solutions of Partial Differential Equations with Adaptive Multigrid Methods results for the solution of partial differential equations based on the software platform UG. State/coarsening, robust parallel multigrid methods, various dis cretizations, dynamic load balancing, mapping and grid

Wieners, Christian

252

Ultrafast infrared studies of complex ligand rearrangements in solution  

SciTech Connect (OSTI)

The complete description of a chemical reaction in solution depends upon an understanding of the reactive molecule as well as its interactions with the surrounding solvent molecules. Using ultrafast infrared spectroscopy it is possible to observe both the solute-solvent interactions and the rearrangement steps which determine the overall course of a chemical reaction. The topics addressed in these studies focus on reaction mechanisms which require the rearrangement of complex ligands and the spectroscopic techniques necessary for the determination of these mechanisms. Ligand rearrangement is studied by considering two different reaction mechanisms for which the rearrangement of a complex ligand constitutes the most important step of the reaction. The first system concerns the rearrangement of a cyclopentadienyl ring as the response of an organometallic complex to a loss of electron density. This mechanism, commonly referred to as ''ring slip'', is frequently cited to explain reaction mechanisms. However, the ring slipped intermediate is too short-lived to be observed using conventional methods. Using a combination of ultrafast infrared spectroscopy and electronic structure calculations it has been shown that the intermediate exists, but does not form an eighteen-electron intermediate as suggested by traditional molecular orbital models. The second example examines the initial steps of alkyne polymerization. Group 6 (Cr, Mo, W) pentacarbonyl species are generated photolytically and used to catalyze the polymerization of unsaturated hydrocarbons through a series of coordination and rearrangement steps. Observing this reaction on the femto- to millisecond timescale indicates that the initial coordination of an alkyne solvent molecule to the metal center results in a stable intermediate that does not rearrange to form the polymer precursor. This suggests that polymerization requires the dissociation of additional carbonyl ligands before rearrangement can occur. Overall, this research demonstrates the importance of examining reaction dynamics on the ultrafast timescale. In the case of both ring slip and alkyne polymerization, early time dynamics have been invaluable in understanding the exact reaction mechanisms which show important differences from previously accepted models.

Payne, Christine K.

2003-05-31T23:59:59.000Z

253

Atomic detail brownian dynamics simulations of concentrated protein...  

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

detail brownian dynamics simulations of concentrated protein solutions with a mean field treatment of hydrodynamic Atomic detail brownian dynamics simulations of concentrated...

254

PHYSICAL REVIEW B 85, 205431 (2012) Momentum-resolved electron dynamics of image-potential states on Cu and Ag surfaces  

E-Print Network [OSTI]

Physik und Zentrum f¨ur Materialwissenschaften, Philipps-Universit¨at, D-35032 Marburg, Germany 2 Country, Spain 5 ERATO, Japan Science and Technology Agency (JST), 3-2-1, Sakado, Takatsu-ku, Kawasaki 213) The dependence of the inelastic lifetime of electrons in the first n = 1 image-potential state of clean and rare

255

Equilibrium and dynamics of ionic solutions  

E-Print Network [OSTI]

The present work is motivated by the desire to understand the physical mechanism underlying the propagation of nervous influx in neurons as well as the modulation and summation of electrical signals during their progression ...

Anton, Mihai

2009-01-01T23:59:59.000Z

256

Brownian Dynamics Simulation of Protein Solutions: Structural...  

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

for understanding the behavior of many fundamental cellular processes, such as protein folding, self-assembly, biochemical reactions, and signal transduction. Here, we describe...

257

Bifurcations of nonlinear ion acoustic travelling waves in the frame of a Zakharov-Kuznetsov equation in magnetized plasma with a kappa distributed electron  

SciTech Connect (OSTI)

Bifurcations of nonlinear propagation of ion acoustic waves (IAWs) in a magnetized plasma whose constituents are cold ions and kappa distributed electron are investigated using a two component plasma model. The standard reductive perturbation technique is used to derive the Zakharov-Kuznetsov (ZK) equation for IAWs. By using the bifurcation theory of planar dynamical systems to this ZK equation, the existence of solitary wave solutions and periodic travelling wave solutions is established. All exact explicit solutions of these travelling waves are determined. The results may have relevance in dense space plasmas.

Kumar Samanta, Utpal [Department of Mathematics, Bankura Christian College, Bankura 722101 (India) [Department of Mathematics, Bankura Christian College, Bankura 722101 (India); Department of Mathematics, Visva Bharati University, Santinekatan 731235 (India); Saha, Asit [Department of Mathematics, Sikkim Manipal Institute of Technology, Majitar, Rangpo, East-Sikkim 737136 (India)] [Department of Mathematics, Sikkim Manipal Institute of Technology, Majitar, Rangpo, East-Sikkim 737136 (India); Chatterjee, Prasanta [Department of Mathematics, Visva Bharati University, Santinekatan 731235 (India)] [Department of Mathematics, Visva Bharati University, Santinekatan 731235 (India)

2013-05-15T23:59:59.000Z

258

PROBING DYNAMICS OF ELECTRON ACCELERATION WITH RADIO AND X-RAY SPECTROSCOPY, IMAGING, AND TIMING IN THE 2002 APRIL 11 SOLAR FLARE  

SciTech Connect (OSTI)

Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic three-dimensional modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration region radio component has distinctly different (1) spectrum, (2) light curves, (3) spatial location, and, thus, (4) physical parameters from those of the separately identified trapped or precipitating electron components. To derive evolution of physical parameters of the radio sources we apply forward fitting of the radio spectrum time sequence with the gyrosynchrotron source function with five to six free parameters. At the stage when the contribution from the acceleration region dominates the radio spectrum, the X-ray- and radio-derived electron energy spectral indices agree well with each other. During this time the maximum energy of the accelerated electron spectrum displays a monotonic increase with time from {approx}300 keV to {approx}2 MeV over roughly one minute duration indicative of an acceleration process in the form of growth of the power-law tail; the fast electron residence time in the acceleration region is about 2-4 s, which is much longer than the time of flight and so requires a strong diffusion mode there to inhibit free-streaming propagation. The acceleration region has a relatively strong magnetic field, B {approx} 120 G, and a low thermal density, n{sub e} {approx}< 2 Multiplication-Sign 10{sup 9} cm{sup -3}. These acceleration region properties are consistent with a stochastic acceleration mechanism.

Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Kontar, Eduard P. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2013-05-10T23:59:59.000Z

259

Photon Echo Studies on Coherence Dynamics in the Photosynthetic Bacterial Reaction Center  

E-Print Network [OSTI]

molecular understanding of electronic and vibrational couplings governing the dynamics of excitation

Ryu, Seungwan

2013-01-01T23:59:59.000Z

260

Dynamical steering in an electron transfer surface reaction: Oriented NO(v = 3, 0.08 < E{sub i} < 0.89 eV) relaxation in collisions with a Au(111) surface  

SciTech Connect (OSTI)

We report measurements of the incidence translational energy dependence of steric effects in collisions of NO(v = 3) molecules with a Au(111) surface using a recently developed technique to orient beams of vibrationally excited NO molecules at incidence energies of translation between 0.08 and 0.89 eV. Incidence orientation dependent vibrational state distributions of scattered molecules are detected by means of resonance enhanced multiphoton ionization spectroscopy. Molecules oriented with the N-end towards the surface exhibit a higher vibrational relaxation probability than those oriented with the O-end towards the surface. This strong orientation dependence arises from the orientation dependence of the underlying electron transfer reaction responsible for the vibrational relaxation. At reduced incidence translational energy, we observe a reduced steric effect. This reflects dynamical steering and re-orientation of the NO molecule upon its approach to the surface.

Bartels, Nils; Golibrzuch, Kai; Bartels, Christof; Schfer, Tim, E-mail: tschaef4@gwdg.de [Institute of Physical Chemistry, Georg-August University of Gttingen, Tammannstrae 6, 37077 Gttingen (Germany)] [Institute of Physical Chemistry, Georg-August University of Gttingen, Tammannstrae 6, 37077 Gttingen (Germany); Chen, Li [Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Am Faberg 11, 37077 Gttingen (Germany)] [Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Am Faberg 11, 37077 Gttingen (Germany); Auerbach, Daniel J.; Wodtke, Alec M. [Institute of Physical Chemistry, Georg-August University of Gttingen, Tammannstrae 6, 37077 Gttingen (Germany) [Institute of Physical Chemistry, Georg-August University of Gttingen, Tammannstrae 6, 37077 Gttingen (Germany); Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Am Faberg 11, 37077 Gttingen (Germany)

2014-02-07T23:59:59.000Z

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261

Hybrid Planar FEM in Magnetoresonance Regime: Control of Dynamical Chaos  

E-Print Network [OSTI]

We establish the influence of nonlinear electron dynamics in the magnetostatic field of a hybrid planar free-electron maser on its gain and interaction efficiency. Even for the `ideal' undulator magnetic field the presence of uniform longitudinal (guide) magnetic field potentially leads to the existence of chaotic zone around certain (magnetoresonant) value of the guide magnetic field. The width of the chaotic zone is given by the Chirikov resonance-overlap criterion applied to the normal undulator and cyclotron frequencies with respect to the coupling induced by the undulator magnetic field. Using analytical asymptotically exact solutions for trajectories of individual test electrons, we show that the magnetoresonant multiplier in electron trajectories is also present in the expression for the gain. The same Chirikov resonance-overlap criterion allows us to estimate analytically the maximal magnetoresonant gain of a hybrid planar free-electron maser showing that, in spite of the well-known drop in the gain for the exact magnetoresonance, the operation regime in the zone of regular dynamics slightly above the magnetoresonant value of the guide magnetic field is the preferable one.

Vitaliy A. Goryashko; Kostyantyn Ilyenko; Anatoliy Opanasenko

2008-06-18T23:59:59.000Z

262

CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES  

E-Print Network [OSTI]

CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES C.F.F. KARNEY, NJ. FISCH Plasma Physics Laboratory of the generation of steady-state currents by electron cyclotron waves are explored. A numerical solution of electron cyclotron wave absorption appears to be one of the more promising schemes of providing a steady

Karney, Charles

263

A Note on Tubular Brane Dynamics  

E-Print Network [OSTI]

We present new time dependent solutions for the dynamics of tubular D2-branes. We comment on the connection to cosmic string dynamics and explicitly give a few simple examples of oscillating and rotating brane configurations.

Jose J. Blanco-Pillado

2005-04-19T23:59:59.000Z

264

Hole burning with pressure and electric field: A window on the electronic structure and energy transfer dynamics of bacterial antenna complexes  

SciTech Connect (OSTI)

Light-harvesting (LH) complexes of cyclic (C{sub n}) symmetry from photosynthetic bacteria are studied using absorption and high pressure- and Stark-hole burning spectroscopies. The B800 absorption band of LH2 is inhomogeneously broadened while the B850 band of LH2 and the B875 band of the LH1 complex exhibit significant homogeneous broadening due to ultra-fast inter-exciton level relaxation. The B800{r_arrow}B850 energy transfer rate of ({approximately}2 ps){sup {minus}1} as determined by hole burning and femtosecond pump-probe spectroscopies, is weakly dependent on pressure and temperature, both of which significantly affect the B800-B850 energy gap. The resilience is theoretically explained in terms of a modified Foerster theory with the spectral overlap provided by the B800 fluorescence origin band and weak vibronic absorption bands of B850. Possible explanations for the additional sub-picosecond relaxation channel of B800 observed with excitation on the blue side of B800 are given. Data from pressure and temperature dependent studies show that the B800 and B850 bacteriochlorophyll a (BChl a) molecules are weakly and strongly excitonically coupled, respectively, which is consistent with the X-ray structure of LH2. The B875 BChl a molecules are also strongly coupled. It is concluded that electron-exchange, in addition to electrostatic interactions, is important for understanding the strong coupling of the B850 and B875 rings. The large linear pressure shifts of {approximately}{minus}0.6 cm{sup {minus}1}/MPa associated with B850 and B875 can serve as important benchmarks for electronic structure calculations.

Wu, H.M.

1999-02-12T23:59:59.000Z

265

Liquid-state polaron theory of the hydrated electron revisited  

E-Print Network [OSTI]

The quantum path integral/classical liquid-state theory of Chandler and co-workers, created to describe an excess electron in solvent, is re-examined for the hydrated electron. The portion that models electron-water density correlations is replaced by two equations: the range optimized random phase approximation (RO-RPA), and the DRL approximation to the "two-chain" equation, both shown previously to describe accurately the static structure and thermodynamics of strongly charged polyelectrolyte solutions. The static equilibrium properties of the hydrated electron are analyzed using five different electron-water pseudopotentials. The theory is then compared with data from mixed quantum/classical Monte Carlo and molecular dynamics simulations using these same pseudopotentials. It is found that the predictions of the RO-RPA and DRL-based polaron theories are similar and improve upon previous theory, with values for almost all properties analyzed in reasonable quantitative agreement with the available simulation data. Also, it is found using the Larsen, Glover and Schwartz pseudopotential that the theories give values for the solvation free energy that are at least three times larger than that from experiment.

James P. Donley; David R. Heine; Caleb A. Tormey; David T. Wu

2014-12-25T23:59:59.000Z

266

Development of the doppler electron velocimeter: theory.  

SciTech Connect (OSTI)

Measurement of dynamic events at the nano-scale is currently impossible. This paper presents the theoretical underpinnings of a method for making these measurements using electron microscopes. Building on the work of Moellenstedt and Lichte who demonstrated Doppler shifting of an electron beam with a moving electron mirror, further work is proposed to perfect and utilize this concept in dynamic measurements. Specifically, using the concept of ''fringe-counting'' with the current principles of transmission electron holography, an extension of these methods to dynamic measurements is proposed. A presentation of the theory of Doppler electron wave shifting is given, starting from the development of the de Broglie wave, up through the equations describing interference effects and Doppler shifting in electron waves. A mathematical demonstration that Doppler shifting is identical to the conceptually easier to understand idea of counting moving fringes is given by analogy to optical interferometry. Finally, potential developmental experiments and uses of a Doppler electron microscope are discussed.

Reu, Phillip L.

2007-03-01T23:59:59.000Z

267

Introduction to Accelerated Molecular Dynamics  

SciTech Connect (OSTI)

Molecular Dynamics is the numerical solution of the equations of motion of a set of atoms, given an interatomic potential V and some boundary and initial conditions. Molecular Dynamics is the largest scale model that gives unbiased dynamics [x(t),p(t)] in full atomistic detail. Molecular Dynamics: is simple; is 'exact' for classical dynamics (with respect to a given V); can be used to compute any (atomistic) thermodynamical or dynamical properties; naturally handles complexity -- the system does the right thing at the right time. The physics derives only from the interatomic potential.

Perez, Danny [Los Alamos National Laboratory

2012-07-10T23:59:59.000Z

268

THE DAYLIGHTING SOLUTION  

E-Print Network [OSTI]

1980, pp.l4-20 THE DAYLIGHTING SOLUTION Stephen SelkowitzEEB-W-80-19 W-74 THE DAYLIGHTING SOLUTION Stephen Selkowitz

Selkowitz, Stephen

2013-01-01T23:59:59.000Z

269

Free-energy functional of the electronic potential for Schrdinger-Poisson theory  

E-Print Network [OSTI]

In the study of model electronic device systems where electrons are typically under confinement, a key obstacle is the need to iteratively solve the coupled Schr\\"{o}dinger-Poisson (SP) equation. It is possible to bypass this obstacle by adopting a variational approach and obtaining the solution of the SP equation by minimizing a functional. Further, using molecular dynamics methods that treat the electronic potential as a dynamical variable, the functional can be minimized on the fly in conjunction with the update of other dynamical degrees of freedom leading to considerable reduction in computational costs. But such approaches require access to a true free-energy functional, one that evaluates to the equilibrium free energy at its minimum. In this paper, we present a variational formulation of the Schr\\"{o}dinger-Poisson (SP) theory with the needed free-energy functional of the electronic potential. We apply our formulation to semiconducting nanostructures and provide the expression of the free-energy functional for narrow channel quantum wells where the local density approximation yields accurate physics and for the case of wider channels where Thomas-Fermi approximation is valid.

Vikram Jadhao; Kaushik Mitra; Francisco J. Solis; Monica Olvera de la Cruz

2014-12-15T23:59:59.000Z

270

Scalability of dynamic traffic assignment  

E-Print Network [OSTI]

This research develops a systematic approach to analyze the computational performance of Dynamic Traffic Assignment (DTA) models and provides solution techniques to improve their scalability for on-line applications for ...

Wen, Yang, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

271

ESR lineshape and {sup 1}H spin-lattice relaxation dispersion in propylene glycol solutions of nitroxide radicals Joint analysis  

SciTech Connect (OSTI)

Electron Spin Resonance (ESR) spectroscopy and Nuclear Magnetic Relaxation Dispersion (NMRD) experiments are reported for propylene glycol solutions of the nitroxide radical: 4-oxo-TEMPO-d{sub 16} containing {sup 15}N and {sup 14}N isotopes. The NMRD experiments refer to {sup 1}H spin-lattice relaxation measurements in a broad frequency range (10 kHz20 MHz). A joint analysis of the ESR and NMRD data is performed. The ESR lineshapes give access to the nitrogen hyperfine tensor components and the rotational correlation time of the paramagnetic molecule. The NMRD data are interpreted in terms of the theory of paramagnetic relaxation enhancement in solutions of nitroxide radicals, recently presented by Kruk et al. [J. Chem. Phys. 138, 124506 (2013)]. The theory includes the effect of the electron spin relaxation on the {sup 1}H relaxation of the solvent. The {sup 1}H relaxation is caused by dipole-dipole interactions between the electron spin of the radical and the proton spins of the solvent molecules. These interactions are modulated by three dynamic processes: relative translational dynamics of the involved molecules, molecular rotation, and electron spin relaxation. The sensitivity to rotation originates from the non-central positions of the interacting spin in the molecules. The electronic relaxation is assumed to stem from the electron spinnitrogen spin hyperfine coupling, modulated by rotation of the radical molecule. For the interpretation of the NMRD data, we use the nitrogen hyperfine coupling tensor obtained from ESR and fit the other relevant parameters. The consistency of the unified analysis of ESR and NMRD, evaluated by the agreement between the rotational correlation times obtained from ESR and NMRD, respectively, and the agreement of the translation diffusion coefficients with literature values obtained for pure propylene glycol, is demonstrated to be satisfactory.

Kruk, D., E-mail: danuta.kruk@matman.uwm.edu.pl [University of Warmia and Mazury in Olsztyn, Faculty of Mathematics and Computer Science, Sloneczna 54, PL-10710 Olsztyn (Poland); Hoffmann, S. K.; Goslar, J.; Lijewski, S. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznan (Poland)] [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznan (Poland); Kubica-Misztal, A.; Korpa?a, A.; Oglodek, I.; Moscicki, J. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)] [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Kowalewski, J. [Arrhenius Laboratory, Department of Materials and Environmental Chemistry, Stockholm University, S-106 91 Stockholm (Sweden)] [Arrhenius Laboratory, Department of Materials and Environmental Chemistry, Stockholm University, S-106 91 Stockholm (Sweden); Rssler, E. A. [Universitt Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany)] [Universitt Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany)

2013-12-28T23:59:59.000Z

272

Electron tomography of dislocation structures  

SciTech Connect (OSTI)

Recent developments in the application of electron tomography for characterizing microstructures in crystalline solids are described. The underlying principles for electron tomography are presented in the context of typical challenges in adapting the technique to crystalline systems and in using diffraction contrast imaging conditions. Methods for overcoming the limitations associated with the angular range, the number of acquired images, and uniformity of image contrast are introduced. In addition, a method for incorporating the real space coordinate system into the tomogram is presented. As the approach emphasizes development of experimental solutions to the challenges, the solutions developed and implemented are presented in the form of examples.

Liu, G.S.; House, S.D.; Kacher, J. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Tanaka, M.; Higashida, K. [Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Robertson, I.M., E-mail: irobertson@wisc.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

2014-01-15T23:59:59.000Z

273

Financing Solutions | Department of Energy  

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

Solution Center Financing Solutions Financing Solutions Transitioning to a clean energy economy requires innovative financing solutions that enable state, local, and tribal...

274

THz Dynamic Nuclear Polarization NMR  

E-Print Network [OSTI]

Dynamic nuclear polarization (DNP) increases the sensitivity of nuclear magnetic resonance (NMR) spectroscopy by using high frequency microwaves to transfer the polarization of the electrons to the nuclear spins. The ...

Nanni, Emilio Alessandro

275

A Birkhoff theorem for Shape Dynamics  

E-Print Network [OSTI]

Shape Dynamics is a theory of gravity that replaces refoliation invariance for spatial Weyl invariance. Those solutions of the Einstein equations that have global, constant mean curvature slicings, are mirrored by solutions in Shape Dynamics. However, there are solutions of Shape Dynamics that have no counterpart in General relativity, just as there are solutions of GR that are not completely foliable by global constant mean curvature slicings (such as the Schwarzschild spacetime). It is therefore interesting to analyze directly the equations of motion of Shape Dynamics in order to find its own solutions, irrespective of properties of known solutions of GR. Here I perform a first study in this direction by utilizing the equations of motion of Shape Dynamics in a spherically symmetric, asymptotically flat ansatz to derive an analogue of the Birkhoff theorem. There are two significant differences with respect to the usual Birkhoff theorem in GR. The first regards the construction of the solution: the spatial Weyl gauge freedom of shape dynamics is used to simplify the problem, and boundary conditions are required. In fact the derivation is simpler than the usual Birkhof theorem as no Christoffel symbols are needed. The second, and most important difference is that the solution obtained is uniquely the isotropic wormhole solution, in which no singularity is present, as opposed to maximally extended Schwarzschild. This provides an explicit example of the breaking of the duality between General relativity and Shape Dynamics, and exhibits some of its consequences.

Henrique Gomes

2014-04-02T23:59:59.000Z

276

2011 -2012 ...real solutions  

E-Print Network [OSTI]

such as recreation potential of disused quarries, use of innovative electronic methods of environmental

Paxton, Anthony T.

277

Attosecond electronic and nuclear quantum photodynamics of the ozone molecule  

SciTech Connect (OSTI)

Coupled electron-nuclear dynamics simulations are investigated for the ozone molecule on the attosecond time scale. The initial wavepacket is pumped as a coherent superposition of two or three electronic states.

Halsz, G. J. [Department of Information Technology, University of Debrecen, H-4010 Debrecen, PO Box 12 (Hungary)] [Department of Information Technology, University of Debrecen, H-4010 Debrecen, PO Box 12 (Hungary); Perveaux, A.; Lasorne, B.; Gatti, F. [CTMM, Institut Charles Gerhardt Montpellier, F-34095 Montpellier Cedex 5 (France)] [CTMM, Institut Charles Gerhardt Montpellier, F-34095 Montpellier Cedex 5 (France); Robb, M. A. [Imperial College London, Department of Chemistry, London SW7 2AZ (United Kingdom)] [Imperial College London, Department of Chemistry, London SW7 2AZ (United Kingdom); Vibk, . [Department of Theoretical Physics, University of Debrecen, H-40410 Debrecen, PO Box 5 (Hungary)] [Department of Theoretical Physics, University of Debrecen, H-40410 Debrecen, PO Box 5 (Hungary)

2013-11-13T23:59:59.000Z

278

Superthermal electron distribution measurements from polarized electron cyclotron emission  

SciTech Connect (OSTI)

Measurements of the superthermal electron distribution can be made by observing the polarized electron cyclotron emission. The emission is viewed along a constant magnetic field surface. This simplifies the resonance condition and gives a direct correlation between emission frequency and kinetic energy of the emitting electron. A transformation technique is formulated which determines the anisotropy of the distribution and number density of superthermals at each energy measured. The steady-state distribution during lower hybrid current drive and examples of the superthermal dynamics as the runaway conditions is varied are presented for discharges in the PLT tokamak. 15 refs., 8 figs.

Luce, T.C.; Efthimion, P.C.; Fisch, N.J.

1988-06-01T23:59:59.000Z

279

Shape Dynamics. An Introduction  

E-Print Network [OSTI]

Shape dynamics is a completely background-independent universal framework of dynamical theories from which all absolute elements have been eliminated. For particles, only the variables that describe the shapes of the instantaneous particle configurations are dynamical. In the case of Riemannian three-geometries, the only dynamical variables are the parts of the metric that determine angles. The local scale factor plays no role. This leads to a shape-dynamic theory of gravity in which the four-dimensional diffeomorphism invariance of general relativity is replaced by three-dimensional diffeomorphism invariance and three-dimensional conformal invariance. Despite this difference of symmetry groups, it is remarkable that the predictions of the two theories -- shape dynamics and general relativity -- agree on spacetime foliations by hypersurfaces of constant mean extrinsic curvature. However, the two theories are distinct, with shape dynamics having a much more restrictive set of solutions. There are indications that the symmetry group of shape dynamics makes it more amenable to quantization and thus to the creation of quantum gravity. This introduction presents in simple terms the arguments for shape dynamics, its implementation techniques, and a survey of existing results.

Julian Barbour

2011-05-01T23:59:59.000Z

280

Dynamics of electromagnetic solitons in a relativistic plasma  

SciTech Connect (OSTI)

Dynamical features of one-dimensional electromagnetic solitons formed in a relativistic interaction of a linearly polarized laser light with underdense cold plasma are investigated. The relativistic Lorentz force in an intense laser light pushes electrons into longitudinal motion, generating coupled longitudinal-transverse waves. In a weakly relativistic approximation these modes are well described by the generalized nonlinear Schroedinger type of equation, with two extra nonlocal terms. Here, an original analytical solution for a moving electromagnetic soliton is derived in an implicit form. For an isolated soliton, our analysis shows that the motion downshifts the soliton eigenfrequency and decreases its amplitude. The effect of the soliton velocity on the stability is analytically predicted and checked numerically. Results show shifting of the stability region toward larger amplitudes in comparison to the standing soliton case. Rich dynamics with examples of (un)stable soliton propagation and breather creation and formation of unstable cusp-type structures is exposed numerically.

Mancic, Ana; Hadzievski, Ljupco; Skoric, Milos M. [Department of Physics, Faculty of Sciences and Mathematics, University of Nis, P. O. B. 224, 18001 Nis (Serbia and Montenegro); Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia and Montenegro); National Institute for Fusion Science, Toki, 509-5292 (Japan)

2006-05-15T23:59:59.000Z

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


281

Dynamics of Bianchi type I elastic spacetimes  

E-Print Network [OSTI]

We study the global dynamical behavior of spatially homogeneous solutions of the Einstein equations in Bianchi type I symmetry, where we use non-tilted elastic matter as an anisotropic matter model that naturally generalizes perfect fluids. Based on our dynamical systems formulation of the equations we are able to prove that (i) toward the future all solutions isotropize; (ii) toward the initial singularity all solutions display oscillatory behavior; solutions do not converge to Kasner solutions but oscillate between different Kasner states. This behavior is associated with energy condition violation as the singularity is approached.

Simone Calogero; J. Mark Heinzle

2007-06-26T23:59:59.000Z

282

Future Climate Engineering Solutions  

E-Print Network [OSTI]

Future Climate Engineering Solutions Joint report 13 engineering participating engeneering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Engineering Solutions A Climate call from engineers. . . . . . . . . . . . . . . . . . . . .23 Summaries of National Reports . . . . . . . . . . . . . . . . . . . .25 Summary of The Climate Plan

283

Borla Performance Industries, Inc. | Department of Energy  

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

Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic...

284

California Lithium Battery, Inc. | Department of Energy  

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

Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic...

285

Electron Dynamics in Metallic Nanoparticles M. Aeschlimann  

E-Print Network [OSTI]

nanoparticles are discussed in the light of the results of line width measurements and femtosecond pump...............................................................................................................3 II. ADSORPTION OF LIGHT IN METALLIC NANOPARTICLES...................................4 A. General...............................................18 C. Heat transfer between the nanoparticles and the support

Bauer, Michael

286

Dynamics in the quantum Hall effect and the phase diagram of graphene  

E-Print Network [OSTI]

The dynamics responsible for lifting the degeneracy of the Landau levels in the quantum Hall (QH) effect in graphene is studied by utilizing a low-energy effective model with a contact interaction. A detailed analysis of the solutions of the gap equation for Dirac quasiparticles is performed at both zero and nonzero temperatures. The characteristic feature of the solutions is that the order parameters connected with the QH ferromagnetism and magnetic catalysis scenarios necessarily coexist. The solutions reproduce correctly the experimentally observed novel QH plateaus in graphene in strong magnetic fields. The phase diagram of this system in the plane of temperature and electron chemical potential is analyzed. The phase transitions corresponding to the transitions between different QH plateaus in graphene are described.

E. V. Gorbar; V. P. Gusynin; V. A. Miransky; I. A. Shovkovy

2008-08-28T23:59:59.000Z

287

Propagation of a cloud of hot electrons in the regime of fast relaxation  

SciTech Connect (OSTI)

The propagation of a cloud of hot electrons and generation of Langmuir waves are investigated using numerical simulation of the quasilinear equations and analytical gas-dynamic theory. The validity of the gas-dynamic theory is investigated and the accuracy of Ryutov and Sagdeev's gas-dynamic equations is explored. It is found that inclusion of spontaneous emission terms in the gas-dynamic equations is necessary for self-consistency of analytical solutions. Results of numerical simulations show that the electron distribution function relaxes to a plateau state and excites Langmuir waves. Evolution of the upper boundary and the height of the plateau are investigated and it is found at a given time and location there are three different regions in the electron beam distribution which correspond to unrelaxed, partially relaxed, and completely relaxed states. In the completely relaxed region there is a good agreement between the results of numerical simulation and the predictions of gas-dynamic theory. As the beam propagates at a given location slower electrons arriving later excite Langmuir waves at lower velocities and reabsorb the waves generated at slightly higher velocities. Hence the upper boundary of the plateau is not constant and moves to lower velocities with time. Results of numerical simulations show there is an abrupt change in reabsorption of waves near the upper boundary such that damping is maximal near this velocity and decreases very rapidly for higher velocities. The coordinate extent of the beam and waves increases with time but their profiles remain similar at all times and this situation enables a self-similar solution to be used. For the total wave energy density good consistency is found between the numerical results and gas-dynamic theory. In the case of an initially unstable beam distribution function, Langmuir wave pile-up near the injection site is observed and it is found that its efficiency depends on temperature and the mean injection velocity of the beam distribution function. These piled-up waves are slowly damped out due to weak Landau damping at the tail of cold background distribution function and propagate very slowly at their group velocity.

Foroutan, G.R.; Li, B.; Robinson, P.A.; Cairns, I.H.; Moslehi-Fard, M. [School of Physics, University of Sydney, New South Wales 2006, Sydney (Australia) and Faculty of Physics, Tabriz University, Tabriz 51664 (Iran); School of Physics, University of Sydney, New South Wales 2006, Sydney (Australia); Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of)

2005-04-15T23:59:59.000Z

288

Page 1 of 10 Electronic Neurons  

E-Print Network [OSTI]

of neurorehabilitative devices for blast injury. Constraint induced (CI) movement therapy has recently been shownPage 1 of 10 Draft Electronic Neurons: From Biomimetic Robots to Blast Neurorehabilitation Joseph on nonlinear dynamical models of neuron and synapse behavior. UCSD electronic neurons (ENs) are analog

Ayers, Joseph

289

Bitcoin a Peer-to-Peer payment solution [Security Considerations  

E-Print Network [OSTI]

Bitcoin a Peer-to-Peer payment solution [Security Considerations] Jean-Guillaume Dumas University of distribution in the network 2. A PEER-TO-PEER PAYMENT SYSTEM: BITCOIN 2.1 Traditional Banking Electronic solutions like BitCoin (based on a peer- to-peer1 network). Here is a summary of the specifications of five

Dumas, Jean-Guillaume

290

Ab Initio Molecular Dynamics Bull. Korean Chem. Soc. 2003, Vol. 24, No. 6 1 Ab Initio Molecular Dynamics with Born-Oppenheimer and Extended  

E-Print Network [OSTI]

Dynamics with Born-Oppenheimer and Extended Lagrangian Methods Using Atom Centered Basis Functions H calculations. For Born-Oppenheimer methods, the electronic structure calculations are converged, whereas trajectory calculations, Born-Oppenheimer dynamics, Extended Lagrangian dynamics, ADMP Introduction

Schlegel, H. Bernhard

291

Natural geometric representation for electron local observables  

SciTech Connect (OSTI)

An existence of the quartic identities for the electron local observables that define orthogonality relations for the 3D quantities quadratic in the electron observables is found. It is shown that the joint solution of the quartic and bilinear identities for the electron observables defines a unique natural representation of the observables. In the natural representation the vector type electron local observables have well-defined fixed positions with respect to a local 3D orthogonal reference frame. It is shown that the natural representation of the electron local observables can be defined in six different forms depending on a choice of the orthogonal unit vectors. The natural representation is used to determine the functional dependence of the electron wave functions on the local observables valid for any shape of the electron wave packet. -- Highlights: Quartic identities that define the orthogonality relations for the electron local observables are found. Joint solution of quartic and bilinear identities defines a unique natural representation of the electron local observables. Functional dependence of the electron wave functions on the electron local observables is determined.

Minogin, V.G., E-mail: minogin@isan.troitsk.ru

2014-03-15T23:59:59.000Z

292

Solution deposition assembly  

DOE Patents [OSTI]

Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

2014-01-21T23:59:59.000Z

293

Electron Impedances  

SciTech Connect (OSTI)

It is only recently, and particularly with the quantum Hall effect and the development of nanoelectronics, that impedances on the scale of molecules, atoms and single electrons have gained attention. In what follows the possibility that characteristic impedances might be defined for the photon and the single free electron is explored is some detail, the premise being that the concepts of electrical and mechanical impedances are relevant to the elementary particle. The scale invariant quantum Hall impedance is pivotal in this exploration, as is the two body problem and Mach's principle.

P Cameron

2011-12-31T23:59:59.000Z

294

Mixed oxide solid solutions  

DOE Patents [OSTI]

The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.

Magno, Scott (Dublin, CA); Wang, Ruiping (Fremont, CA); Derouane, Eric (Liverpool, GB)

2003-01-01T23:59:59.000Z

295

Electronic Coupling Dependence of Ultrafast Interfacial Electron Transfer on Nanocrystalline Thin Films and Single Crystal  

SciTech Connect (OSTI)

The long-term goal of the proposed research is to understand electron transfer dynamics in nanoparticle/liquid interface. This knowledge is essential to many semiconductor nanoparticle based devices, including photocatalytic waste degradation and dye sensitized solar cells.

Lian, Tianquan

2014-04-22T23:59:59.000Z

296

Drama in Dynamics: Boom, Splash, and Speed  

SciTech Connect (OSTI)

The full nature of chemistry and physics cannot be captured by static calculations alone. Dynamics calculations allow the simulation of time-dependent phenomena. This facilitates both comparisons with experimental data and the prediction and interpretation of details not easily obtainable from experiments. Simulations thus provide a direct link between theory and experiment, between microscopic details of a system and macroscopic observed properties. Many types of dynamics calculations exist. The most important distinction between the methods and the decision of which method to use can be described in terms of the size and type of molecule/reaction under consideration and the type and level of accuracy required in the final properties of interest. These considerations must be balanced with available computational codes and resources as simulations to mimic ''real-life'' may require many time steps. As indicated in the title, the theme of this thesis is dynamics. The goal is to utilize the best type of dynamics for the system under study while trying to perform dynamics in the most accurate way possible. As a quantum chemist, this involves some level of first principles calculations by default. Very accurate calculations of small molecules and molecular systems are now possible with relatively high-level ab initio quantum chemistry. For example, a quantum chemical potential energy surface (PES) can be developed ''on-the-fly'' with dynamic reaction path (DRP) methods. In this way a classical trajectory is developed without prior knowledge of the PES. In order to treat solvation processes and the condensed phase, large numbers of molecules are required, especially in predicting bulk behavior. The Effective Fragment Potential (EFP) method for solvation decreases the cost of a fully quantum mechanical calculation by dividing a chemical system into an ab initio region that contains the solute and an ''effective fragment'' region that contains the remaining solvent molecules. But, despite the reduced cost relative to fully QM calculations, the EFP method, due to its complex, QM-based potential, does require more computation time than simple interaction potentials, especially when the method is used for large scale molecular dynamics simulations. Thus, the EFP method was parallelized to facilitate these calculations within the quantum chemistry program GAMESS. The EFP method provides relative energies and structures that are in excellent agreement with the analogous fully quantum results for small water clusters. The ability of the method to predict bulk water properties with a comparable accuracy is assessed by performing EFP molecular dynamics simulations. Molecular dynamics simulations can provide properties that are directly comparable with experimental results, for example radial distribution functions. The molecular PES is a fundamental starting point for chemical reaction dynamics. Many methods can be used to obtain a PES; for example, assuming a global functional form for the PES or, as mentioned above, performing ''on-the-fly'' dynamics with Al or semi-empirical calculations at every molecular configuration. But as the size of the system grows, using electronic structure theory to build a PES and, therefore, study reaction dynamics becomes virtually impossible. The program Grow builds a PES as an interpolation of Al data; the goal is to attempt to produce an accurate PES with the smallest number of Al calculations. The Grow-GAMESS interface was developed to obtain the Al data from GAMESS. Classical or quantum dynamics can be performed on the resulting surface. The interface includes the novel capability to build multi-reference PESs; these types of calculations are applicable to problems ranging from atmospheric chemistry to photochemical reaction mechanisms in organic and inorganic chemistry to fundamental biological phenomena such as photosynthesis.

Heather Marie Netzloff

2004-12-19T23:59:59.000Z

297

Dispersant solutions for dispersing hydrocarbons  

DOE Patents [OSTI]

A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.

Tyndall, Richard L. (Clinton, TN)

1997-01-01T23:59:59.000Z

298

Dispersant solutions for dispersing hydrocarbons  

DOE Patents [OSTI]

A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.

Tyndall, R.L.

1997-03-11T23:59:59.000Z

299

Nonaqueous solution synthesis process for preparing oxide powders of lead zirconate titanate and related materials  

DOE Patents [OSTI]

A process is disclosed for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications. 4 figs.

Voigt, J.A.; Sipola, D.L.; Tuttle, B.A.; Anderson, M.T.

1999-06-01T23:59:59.000Z

300

Structural aspects of the solvation shell of lysine and acetylated lysine: A Car-Parrinello and classical molecular dynamics investigation  

SciTech Connect (OSTI)

Lysine acetylation is a post-translational modification, which modulates the affinity of protein-protein and/or protein-DNA complexes. Its crucial role as a switch in signaling pathways highlights the relevance of charged chemical groups in determining the interactions between water and biomolecules. A great effort has been recently devoted to assess the reliability of classical molecular dynamics simulations in describing the solvation properties of charged moieties. In the spirit of these investigations, we performed classical and Car-Parrinello molecular dynamics simulations on lysine and acetylated-lysine in aqueous solution. A comparative analysis between the two computational schemes is presented with a focus on the first solvation shell of the charged groups. An accurate structural analysis unveils subtle, yet statistically significant, differences which are discussed in connection to the significant electronic density charge transfer occurring between the solute and the surrounding water molecules.

Carnevale, V. [Department of Chemistry, Center for Molecular Modeling, University of Pennsylvania, Philadelphia, Pennsylvania, 19104-6323 (United States); Raugei, S. [International School for Advanced Studies (SISSA) and CNR-INFM Democritos, Via Beirut 2, Trieste I-34014 Italy, Trieste (Italy)

2009-12-14T23:59:59.000Z

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


301

TRANSMISSION ELECTRON MICROSCOPY OF WEAKLY DEFORMED ALKALI HALIDE CRYSTALS  

E-Print Network [OSTI]

377 TRANSMISSION ELECTRON MICROSCOPY OF WEAKLY DEFORMED ALKALI HALIDE CRYSTALS H. STRUNK Max'importance croissante du durcissement de la solution solide. Abstract. 2014 Transmission electron microscopy (TEM Abstracts 7j66 - 7 I' 1. Introduction. - It is only some years ago that transmission electron microscopy

Boyer, Edmond

302

Predicting binding free energies in solution  

E-Print Network [OSTI]

Recent predictions of absolute binding free energies of host-guest complexes in aqueous solution using electronic structure theory have been encouraging for some systems, while other systems remain problematic for others. In paper I summarize some of the many factors that could easily contribute 1-3 kcal/mol errors at 298 K: three-body dispersion effects, molecular symmetry, anharmonicity, spurious imaginary frequencies, insufficient conformational sampling, wrong or changing ionization states, errors in the solvation free energy of ions, and explicit solvent (and ion) effects that are not well-represented by continuum models. While the paper is primarily a synthesis of previously published work there are two new results: the adaptation of Legendre transformed free energies to electronic structure theory and a use of water clusters that maximizes error cancellation in binding free energies computed using explicit solvent molecules. While I focus on binding free energies in aqueous solution the approach also a...

Jensen, Jan H

2015-01-01T23:59:59.000Z

303

Automatic Radar Antenna Scan Type Recognition in Electronic  

E-Print Network [OSTI]

Automatic Radar Antenna Scan Type Recognition in Electronic Warfare BILLUR BARSHAN BAHAEDDIN ERAVCI in electronic warfare (EW). The stages of the algorithm are scan period estimation, preprocessing (normalization Continuous-wave EW Electronic warfare EM Electromagnetic LFM Linear frequency modulation DTW Dynamic time

Barshan, Billur

304

Electron transfer reactions in microporous solids  

SciTech Connect (OSTI)

We have studied electron transfer quenching of the excited state of Ru(bpy){sub 3}{sup 2+} in aqueous suspensions of zeolites Y, L, and mordenite. The internal pore network of the zeolite is ion-exchanged with methylviologen cations, which quench the excited state of the surface-bound sensitizer. A detailed study of the quenching and charge recombination kinetics, using time-resolved luminescence quenching and transient diffuse reflectance spectroscopies, shows to remarkable effects: first, the excited state quenching is entirely dynamic is large-pore zeolites (L and Y), even when they are prepared as apparently dry'' powders (which still contain significant amounts of internally sited water). Second, a lower limit for the diffusion coefficient of the MV{sup 2+} ion in these zeolites, determined by this technique, is 10{sup {minus}7} cm{sup 2}sec, i.e., only about one order of magnitude slower than a typical ion in liquid water, and 2--3 orders of magnitude faster than charge transfer diffusion of cations in polyelectrolyte films or membranes such as Nafion. Surface sensitization of internally platinized layered oxide semiconductors such as K{sub 4-x}H{sub x}Nb{sub 6}O{sub 17}{center dot}nH{sub 2}O (x {approx} 2.5) yields photocatalysts for the production of H{sub 2} and I{sub 3{minus}} in aqueous iodide solutions. Layered alkali niobates and titanates form a class of zeolitic wide-bandap semiconductors, and are the first examples of photocatalysts that evolve hydrogen from an electrochemically reversible (i.e., non-sacrificial) electron donor with visible light excitation.

Mallouk, T.E.

1992-05-01T23:59:59.000Z

305

Electron CoolingElectron Cooling Sergei Nagaitsev  

E-Print Network [OSTI]

Electron CoolingElectron Cooling Sergei Nagaitsev FNAL - AD April 28, 2005 #12;Electron Cooling methods must "get around the theorem" e.g. by pushing phase-space around. #12;Electron Cooling - Nagaitsev 3 TodayToday''s Menus Menu What is cooling? Types of beam cooling Electron cooling Conclusions #12

Fermilab

306

Three-dimensional dust-ion-acoustic rogue waves in a magnetized dusty pair-ion plasma with nonthermal nonextensive electrons and opposite polarity dust grains  

SciTech Connect (OSTI)

Dust-ion-acoustic (DIA) rogue waves are investigated in a three-dimensional magnetized plasma containing nonthermal electrons featuring Tsallis distribution, both positive and negative ions, and immobile dust grains having both positive and negative charges. Via the reductive perturbation method, a (3?+?1)-dimensional nonlinear Schrdinger (NLS) equation is derived to govern the dynamics of the DIA wave packets. The modulation instability of DIA waves described by the (3?+?1)-dimensional NLS equation is investigated. By means of the similarity transformation and symbolic computation, both the first- and second-order rogue wave solutions of the (3?+?1)-dimensional NLS equation are constructed in terms of rational functions. Moreover, the dynamics properties and the effects of plasma parameters on the nonlinear structures of rogue waves are discussed in detail. The results could be useful for understanding the physical mechanism of rogue waves in laboratory experiments where pair-ion plasmas with electrons and dust grains can be found.

Guo, Shimin, E-mail: gsm861@126.com; Mei, Liquan, E-mail: lqmei@mail.xjtu.edu.cn [School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an 710049 (China)

2014-08-15T23:59:59.000Z

307

[Inelastic electron scattering from surfaces]. [Progress report  

SciTech Connect (OSTI)

This program uses ab-initio and multiple scattering to study surface dynamical processes; high-resolution electron-energy loss spectroscopy is used in particular. Off-specular excitation cross sections are much larger if electron energies are in the LEED range (50--300 eV). The analyses have been extended to surfaces of ordered alloys. Phonon eigenvectors and eigenfrequencies were used as inputs to electron-energy-loss multiple scattering cross section calculations. Work on low-energy electron and positron holography is mentioned.

Not Available

1993-10-01T23:59:59.000Z

308

Integrating Security Solutions to Support nanoCMOS Electronics Research  

E-Print Network [OSTI]

Sinnott,R.O. Asenov,A. Bayliss,C. Davenhall,C. Doherty,T. Harbulot,B. Jones,M. Martin,D. Millar,C. Roy,G. Roy,S. Stewart,G. Watt,J. IEEE International Symposium on Parallel and Distributed Processing Systems with Applications, Sydney Australia, December 2008.

Sinnott, R.O.

309

PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002OpticsPeriodical:Rocky Mountain OTC GSS PIA -|RECORDS

310

PIA - Savannah River Nuclear Solutions Electronic Safeguards Security  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002OpticsPeriodical:Rocky Mountain OTC GSS PIASystem

311

Computational Electronics and Electromagnetics  

SciTech Connect (OSTI)

The Computational Electronics and Electromagnetics thrust area is a focal point for computer modeling activities in electronics and electromagnetics in the Electronics Engineering Department of Lawrence Livermore National Laboratory (LLNL). Traditionally, they have focused their efforts in technical areas of importance to existing and developing LLNL programs, and this continues to form the basis for much of their research. A relatively new and increasingly important emphasis for the thrust area is the formation of partnerships with industry and the application of their simulation technology and expertise to the solution of problems faced by industry. The activities of the thrust area fall into three broad categories: (1) the development of theoretical and computational models of electronic and electromagnetic phenomena, (2) the development of useful and robust software tools based on these models, and (3) the application of these tools to programmatic and industrial problems. In FY-92, they worked on projects in all of the areas outlined above. The object of their work on numerical electromagnetic algorithms continues to be the improvement of time-domain algorithms for electromagnetic simulation on unstructured conforming grids. The thrust area is also investigating various technologies for conforming-grid mesh generation to simplify the application of their advanced field solvers to design problems involving complicated geometries. They are developing a major code suite based on the three-dimensional (3-D), conforming-grid, time-domain code DSI3D. They continue to maintain and distribute the 3-D, finite-difference time-domain (FDTD) code TSAR, which is installed at several dozen university, government, and industry sites.

DeFord, J.F.

1993-03-01T23:59:59.000Z

312

Beam Dynamics for ARIA  

E-Print Network [OSTI]

Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

Ekdahl, Carl

2015-01-01T23:59:59.000Z

313

Crowdsourcing suggestions to programming problems for dynamic  

E-Print Network [OSTI]

). Failing tests thus indicate both missing functionality and incorrect program behavior. We implement CrowdCrowdsourcing suggestions to programming problems for dynamic web development languages Abstract Developers increasingly consult online examples and message boards to find solutions to common programming

Hartmann, Björn

314

Exact solitary solution of Schamel equation in plasmas with negative ions  

SciTech Connect (OSTI)

A theoretical investigation is carried out for understanding the properties of the solitary solution in plasmas with negative ions. Schamel equation for a plasma consisting of electron, positive ions and negative ions has been derived by using the reductive perturbation method. The effects of negative ions and the density on the properties of the solitary solution is discussed. We make use of the extended mapping method and auxiliary equation to obtain the solution of Schamel equation. This solution includes the Jacobi elliptic function solutions, hyperbolic function solutions, rational solutions, and periodic wave solutions. Furthermore, we show that the incorporate negative ion effects in the nonlinear propagation of ion acoustic waves that are controlled by trapped electrons and the results of the solitary solution in plasmas with negative ions model are discussed.

El-Kalaawy, O. H. [Mathematics Department, Faculty of Education, Dammam University, P.O. 2375, Dammam 31451 (Saudi Arabia) and Department of Mathematics, Faculty of Science, Beni-Suef University, Beni-Suef 62511 (Egypt)

2011-11-15T23:59:59.000Z

315

Strategic Biomass Solutions (Mississippi)  

Broader source: Energy.gov [DOE]

The Strategic Biomass Solutions (SBS) was formed by the Mississippi Technology Alliance in June 2009. The purpose of the SBS is to provide assistance to existing and potential companies, investors...

316

Solution to Quiz 1  

E-Print Network [OSTI]

Sep 5, 2013 ... over the next four years: Cash Flow at End of Year Amount of Cash Flow. 1. 1 Million. 2 ... project is 8%. Calculate X . Solution: By definition, the...

jeffb_000

2014-01-14T23:59:59.000Z

317

2013 R&D 100 Award: Movie-mode electron microscope captures nanoscale  

SciTech Connect (OSTI)

A new instrument developed by LLNL scientists and engineers, the Movie Mode Dynamic Transmission Electron Microscope (MM-DTEM), captures billionth-of-a-meter-scale images with frame rates more than 100,000 times faster than those of conventional techniques. The work was done in collaboration with a Pleasanton-based company, Integrated Dynamic Electron Solutions (IDES) Inc. Using this revolutionary imaging technique, a range of fundamental and technologically important material and biological processes can be captured in action, in complete billionth-of-a-meter detail, for the first time. The primary application of MM-DTEM is the direct observation of fast processes, including microstructural changes, phase transformations and chemical reactions, that shape real-world performance of nanostructured materials and potentially biological entities. The instrument could prove especially valuable in the direct observation of macromolecular interactions, such as protein-protein binding and host-pathogen interactions. While an earlier version of the technology, Single Shot-DTEM, could capture a single snapshot of a rapid process, MM-DTEM captures a multiframe movie that reveals complex sequences of events in detail. It is the only existing technology that can capture multiple electron microscopy images in the span of a single microsecond.

Lagrange, Thomas; Reed, Bryan

2014-04-03T23:59:59.000Z

318

2013 R&D 100 Award: Movie-mode electron microscope captures nanoscale  

ScienceCinema (OSTI)

A new instrument developed by LLNL scientists and engineers, the Movie Mode Dynamic Transmission Electron Microscope (MM-DTEM), captures billionth-of-a-meter-scale images with frame rates more than 100,000 times faster than those of conventional techniques. The work was done in collaboration with a Pleasanton-based company, Integrated Dynamic Electron Solutions (IDES) Inc. Using this revolutionary imaging technique, a range of fundamental and technologically important material and biological processes can be captured in action, in complete billionth-of-a-meter detail, for the first time. The primary application of MM-DTEM is the direct observation of fast processes, including microstructural changes, phase transformations and chemical reactions, that shape real-world performance of nanostructured materials and potentially biological entities. The instrument could prove especially valuable in the direct observation of macromolecular interactions, such as protein-protein binding and host-pathogen interactions. While an earlier version of the technology, Single Shot-DTEM, could capture a single snapshot of a rapid process, MM-DTEM captures a multiframe movie that reveals complex sequences of events in detail. It is the only existing technology that can capture multiple electron microscopy images in the span of a single microsecond.

Lagrange, Thomas; Reed, Bryan

2014-07-21T23:59:59.000Z

319

Solutions of Penrose's Equation  

E-Print Network [OSTI]

The computational use of Killing potentials which satisfy Penrose's equation is discussed. Penrose's equation is presented as a conformal Killing-Yano equation and the class of possible solutions is analyzed. It is shown that solutions exist in spacetimes of Petrov type O, D or N. In the particular case of the Kerr background, it is shown that there can be no Killing potential for the axial Killing vector.

E. N. Glass; Jonathan Kress

1998-09-27T23:59:59.000Z

320

ELECTRONIC WARFARE NOVEMBER 2012  

E-Print Network [OSTI]

FM 3-36 ELECTRONIC WARFARE NOVEMBER 2012 DISTRIBUTION RESTRICTION: Approved for public release Electronic Warfare Contents Page PREFACE..............................................................................................................iv Chapter 1 ELECTRONIC WARFARE OVERVIEW ............................................................ 1

US Army Corps of Engineers

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


321

Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy  

E-Print Network [OSTI]

Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that have resisted all other techniques in structural biology. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance (NMR), EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 GHz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 T and below. Here we demonstrate that ~1 kW pulses from a free-electron laser (FEL) can power a pulsed EPR spectrometer at 240 GHz...

Takahashi, S; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S

2012-01-01T23:59:59.000Z

322

Boltzmann-Electron Model in Aleph.  

SciTech Connect (OSTI)

We apply the Boltzmann-electron model in the electrostatic, particle-in-cell, finite- element code Aleph to a plasma sheath. By assuming a Boltzmann energy distribution for the electrons, the model eliminates the need to resolve the electron plasma fre- quency, and avoids the numerical %22grid instability%22 that can cause unphysical heating of electrons. This allows much larger timesteps to be used than with kinetic electrons. Ions are treated with the standard PIC algorithm. The Boltzmann-electron model re- quires solution of a nonlinear Poisson equation, for which we use an iterative Newton solver (NOX) from the Trilinos Project. Results for the spatial variation of density and voltage in the plasma sheath agree well with an analytic model

Hughes, Thomas Patrick; Hooper, Russell

2014-11-01T23:59:59.000Z

323

Introductory statistical mechanics for electron storage rings  

SciTech Connect (OSTI)

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

Jowett, J.M.

1986-07-01T23:59:59.000Z

324

Dynamical Spacetimes from Numerical Hydrodynamics  

E-Print Network [OSTI]

We numerically construct dynamical asymptotically-AdS$_4$ metrics by evaluating the fluid/gravity metric on numerical solutions of dissipative hydrodynamics in (2+1) dimensions. The resulting numerical metrics satisfy Einstein's equations in (3+1) dimensions to high accuracy.

Allan Adams; Nathan Benjamin; Arvin Moghaddam; Wojciech Musial

2014-11-07T23:59:59.000Z

325

Fissile solution measurement apparatus  

DOE Patents [OSTI]

An apparatus for determining the content of a fissile material within a solution by detecting delayed fission neutrons emitted by the fissile material after it is temporarily irradiated by a neutron source. The apparatus comprises a container holding the solution and having a portion defining a neutron source cavity centrally disposed within the container. The neutron source cavity temporarily receives the neutron source. The container has portions defining a plurality of neutron detector ports that form an annular pattern and surround the neutron source cavity. A plurality of neutron detectors count delayed fission neutrons emitted by the fissile material. Each neutron detector is located in a separate one of the neutron detector ports.

Crane, T.W.; Collinsworth, P.R.

1984-06-11T23:59:59.000Z

326

Elastic electron scattering from formic acid  

SciTech Connect (OSTI)

Following our earlier study on the dynamics of low energy electron attachment to formic acid, we report the results of elastic low-energy electron collisions with formic acid. Momentum transfer and angular differential cross sections were obtained by performing fixed-nuclei calculations employing the complex Kohn variational method. We make a brief description of the technique used to account for the polar nature of this polyatomic target and compare our results with available experimental data.

Trevisan, Cynthia S.; Orel, Ann E.; Rescigno, Thomas N.

2006-07-31T23:59:59.000Z

327

Frontier orbital symmetry control of intermolecular electron transfer. Final report, September 15, 1988--December 31, 1994  

SciTech Connect (OSTI)

This report discusses the following topics: the recovery of intermolecular transfer parameters from fluorescence quenching in liquids; photoinduced intramolecular electron transfer in flexible donor/space/acceptor systems containing an extended unsaturated spacer; electron transfer sensitized reaction; the recovery of solute and fractal dimensions from electron transfer quenching data; and frontier orbital symmetry control of back electron transfer.

Stevens, B.

1997-07-01T23:59:59.000Z

328

Role of electron-electron interference in ultrafast time-resolved imaging of electronic wavepackets  

SciTech Connect (OSTI)

Ultrafast time-resolved x-ray scattering is an emerging approach to image the dynamical evolution of the electronic charge distribution during complex chemical and biological processes in real-space and real-time. Recently, the differences between semiclassical and quantum-electrodynamical (QED) theory of light-matter interaction for scattering of ultrashort x-ray pulses from the electronic wavepacket were formally demonstrated and visually illustrated by scattering patterns calculated for an electronic wavepacket in atomic hydrogen [G. Dixit, O. Vendrell, and R. Santra, Proc. Natl. Acad. Sci. U.S.A. 109, 11636 (2012)]. In this work, we present a detailed analysis of time-resolved x-ray scattering from a sample containing a mixture of non-stationary and stationary electrons within both the theories. In a many-electron system, the role of scattering interference between a non-stationary and several stationary electrons to the total scattering signal is investigated. In general, QED and semiclassical theory provide different results for the contribution from the scattering interference, which depends on the energy resolution of the detector and the x-ray pulse duration. The present findings are demonstrated by means of a numerical example of x-ray time-resolved imaging for an electronic wavepacket in helium. It is shown that the time-dependent scattering interference vanishes within semiclassical theory and the corresponding patterns are dominated by the scattering contribution from the time-independent interference, whereas the time-dependent scattering interference contribution do not vanish in the QED theory and the patterns are dominated by the scattering contribution from the non-stationary electron scattering.

Dixit, Gopal [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Santra, Robin [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Department of Physics, University of Hamburg, D-20355 Hamburg (Germany)

2013-04-07T23:59:59.000Z

329

Damping filter method for obtaining spatially localized solutions  

E-Print Network [OSTI]

Spatially localized structures are key components of turbulence and other spatio-temporally chaotic systems. From a dynamical systems viewpoint, it is desirable to obtain corresponding exact solutions, though their existence is not guaranteed. A damping filter method is introduced to obtain variously localized solutions, and adopted into two typical cases. This method introduces a spatially selective damping effect to make a good guess at the exact solution, and we can obtain an exact solution through a continuation with the damping amplitude. First target is a steady solution to Swift-Hohenberg equation, which is a representative of bi-stable systems in which localized solutions coexist, and a model for span-wisely localized cases. Not only solutions belonging to the well-known snaking branches but also those belonging to an isolated branch known as "isolas" are found with a continuation paths between them in phase space extended with the damping amplitude. This indicates that this spatially selective excitation mechanism has an advantage in searching spatially localized solutions. Second target is a spatially localized traveling-wave solution to Kuramoto-Sivashinsky equation, which is a model for stream-wisely localized cases. Since the spatially selective damping effect breaks Galilean and translational invariances, the propagation velocity cannot be determined uniquely while the damping is active, and a singularity arises when these invariances are recovered. We demonstrate that this singularity can be avoided by imposing a simple condition, and a localized traveling-wave solution is obtained with a specific propagation speed.

Toshiki Teramura; Sadayoshi Toh

2014-04-30T23:59:59.000Z

330

Offshore Renewable Energy Solutions  

E-Print Network [OSTI]

power ­ to meet its target of achieving 15% of energy consumption from renewable sources by 2020. CefasOffshore Renewable Energy Solutions #12;Cefas: meeting complex requirements The Centre and maximise resource input on field and lab-based studies ­ saving you time and money.Recognised expertise

331

Interference between electronic lighting and other appliances  

SciTech Connect (OSTI)

This paper presents empirical data from the laboratory and the field to provide an overview of electromagnetic interference between high-efficiency electronic lighting and certain other electronic devices, such as power-line carrier systems, security systems, and remote controls for televisions and VCRs. Reported cases involving both electronic lighting emissions and immunity in building power systems are summarized according to basic interference mechanisms. To illustrate the potential complexities of this problem, the paper describes a case where high-efficiency lighting interfered with a hearing aid. The hearing aid case includes a field survey, laboratory investigations, and recommended solutions to the problem.

Schwabe, R.J.; Zelingher, S. [New York Power Authority, New York, NY (United States); Key, T.; Phipps, K. [EPRI Power Electronics Applications Center, Knoxville, TN (United States)

1995-12-31T23:59:59.000Z

332

Theoretical studies of electronically excited states  

SciTech Connect (OSTI)

Time-dependent density functional theory is the most widely used quantum chemical method for studying molecules in electronically excited states. However, excited states can also be computed within Kohn-Sham density functional theory by exploiting methods that converge the self-consistent field equations to give excited state solutions. The usefulness of single reference self-consistent field based approaches for studying excited states is demonstrated by considering the calculation of several types of spectroscopy including the infrared spectroscopy of molecules in an electronically excited state, the rovibrational spectrum of the NO-Ar complex, core electron binding energies and the emission spectroscopy of BODIPY in water.

Besley, Nicholas A. [School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

2014-10-06T23:59:59.000Z

333

Optically pulsed electron accelerator  

DOE Patents [OSTI]

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, J.S.; Sheffield, R.L.

1985-05-20T23:59:59.000Z

334

Better Buildings Residential Program Solution Center Demonstration...  

Energy Savers [EERE]

Better Buildings Residential Program Solution Center Demonstration Better Buildings Residential Program Solution Center Demonstration Better Buildings Residential Program Solution...

335

Complex Dynamics  

E-Print Network [OSTI]

Complex Dynamics Bernardo Da Costa, Koushik Ramachandran, Jingjing Qu, and I had a two semester learning seminar in complex analysis and potential...

336

Structural Dynamics of a Catalytic Monolayer Probed by Ultrafast  

E-Print Network [OSTI]

REPORTS Structural Dynamics of a Catalytic Monolayer Probed by Ultrafast 2D IR Vibrational Echoes in solutions. Here, we extend the technique to probing the interfacial dynamics and structure of a silica. The structural dynamics, as reported on by a carbonyl stretch vibration of the surface-bound complex, have

Fayer, Michael D.

337

MAP: Multiauctioneer Progressive Auction for Dynamic Spectrum Access  

E-Print Network [OSTI]

to access the licensed spectrum, and dynamic spectrum access (DSA) is one of the fundamental functions of CR solution according to the length of step. Index Terms--Cognitive radio, dynamic spectrum access, auction from scarcity in spectrum resource and inefficiency in spectrum usage. Cognitive radio (CR) or dynamic

Wang, Xinbing

338

Electron beam generation in Tevatron electron lenses  

SciTech Connect (OSTI)

New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices.

Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; /Fermilab; Tiunov, M.; /Novosibirsk, IYF

2006-08-01T23:59:59.000Z

339

Radioluminescence of curium(III) in solutions  

SciTech Connect (OSTI)

The radioluminescence of curium(III) under the action of the intrinsic ..cap alpha..-radiation was studied in aqueous, heavy water, and organic solutions. The luminescence maximum falls at lambda approx. 600 nm. The yield of radioluminescence G is proportional to the concentration (or electronic fraction) of curium, and for a 10/sup -2/ M aqueous solution of Cm(NO/sub 3/)/sub 3/, G approx. 5 x 10/sup -4/ quanta per 100 eV of absorbed energy. In dilute acids the yield of radioluminescence is the same as in neutral solution, but in concentrated acid it is substantially changed. In the presence of ligands (formate, acetate, citrate ions, and others), the yield of the radioluminescence of curium in aqueous solutions increases, which is associated with complex formation, leading to a decrease in the quenching of excited curium by water molecules. The intensification of the radioluminescence of curium in the presence of sodium paratungstate is especially great; it is suggested that in this case a significant role is played by energy transfer from the ligand to curium. H/sub 2/O/sub 2/, NH/sub 2/NH/sub 2/, NH/sub 2/OH, Ce/sup (IV)/, and uranium, neptunium, and plutonium ions in various oxidation states have no great influence on the radioluminescence of curium. Its quenching by NpO/sub 2//sup +/ ions is somewhat greater than by other actinide ions and is associated with the formation of cation-cation complexes of NpO/sub 2//sup 2 +/ with Cm/sup 3 +/. In heavy water and organic solutions, a substantial increase in the radioluminescence yield of curium is observed, which is in good agreement with the data on photoluminescence. The results obtained suggest that the radioluminescence of curium in solutions (in the absence of energy-donor ligands) is excited mainly directly, while the role of energy transfer to curium from the solvent or its radiolysis products is negligible.

Yusov, A.B.; Perminov, V.P.; Krot, N.N.; Kazakov, V.P.

1987-01-01T23:59:59.000Z

340

Single Molecule Spectroscopy of Electron Transfer  

SciTech Connect (OSTI)

The objectives of this research are threefold: (1) to develop methods for the study electron transfer processes at the single molecule level, (2) to develop a series of modifiable and structurally well defined molecular and nanoparticle systems suitable for detailed single molecule/particle and bulk spectroscopic investigation, (3) to relate experiment to theory in order to elucidate the dependence of electron transfer processes on molecular and electronic structure, coupling and reorganization energies. We have begun the systematic development of single molecule spectroscopy (SMS) of electron transfer and summaries of recent studies are shown. There is a tremendous need for experiments designed to probe the discrete electronic and molecular dynamic fluctuations of single molecules near electrodes and at nanoparticle surfaces. Single molecule spectroscopy (SMS) has emerged as a powerful method to measure properties of individual molecules which would normally be obscured in ensemble-averaged measurement. Fluctuations in the fluorescence time trajectories contain detailed molecular level statistical and dynamical information of the system. The full distribution of a molecular property is revealed in the stochastic fluctuations, giving information about the range of possible behaviors that lead to the ensemble average. In the case of electron transfer, this level of understanding is particularly important to the field of molecular and nanoscale electronics: from a device-design standpoint, understanding and controlling this picture of the overall range of possible behaviors will likely prove to be as important as designing ia the ideal behavior of any given molecule.

Michael Holman; Ling Zang; Ruchuan Liu; David M. Adams

2009-10-20T23:59:59.000Z

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


341

Spatiotemporal dynamics of a digital phase-locked loop based coupled map lattice system  

SciTech Connect (OSTI)

We explore the spatiotemporal dynamics of a coupled map lattice (CML) system, which is realized with a one dimensional array of locally coupled digital phase-locked loops (DPLLs). DPLL is a nonlinear feedback-controlled system widely used as an important building block of electronic communication systems. We derive the phase-error equation of the spatially extended system of coupled DPLLs, which resembles a form of the equation of a CML system. We carry out stability analysis for the synchronized homogeneous solutions using the circulant matrix formalism. It is shown through extensive numerical simulations that with the variation of nonlinearity parameter and coupling strength the system shows transitions among several generic features of spatiotemporal dynamics, viz., synchronized fixed point solution, frozen random pattern, pattern selection, spatiotemporal intermittency, and fully developed spatiotemporal chaos. We quantify the spatiotemporal dynamics using quantitative measures like average quadratic deviation and spatial correlation function. We emphasize that instead of using an idealized model of CML, which is usually employed to observe the spatiotemporal behaviors, we consider a real world physical system and establish the existence of spatiotemporal chaos and other patterns in this system. We also discuss the importance of the present study in engineering application like removal of clock-skew in parallel processors.

Banerjee, Tanmoy, E-mail: tbanerjee@phys.buruniv.ac.in; Paul, Bishwajit; Sarkar, B. C. [Department of Physics, University of Burdwan, Burdwan, West Bengal 713 104 (India)] [Department of Physics, University of Burdwan, Burdwan, West Bengal 713 104 (India)

2014-03-15T23:59:59.000Z

342

Biosystem Dynamics & Design | EMSL  

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

Biosystem Dynamics & Design Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems Biosystem Dynamics &...

343

Stability of the electron cyclotron resonance  

E-Print Network [OSTI]

We consider the magnetic AC Stark effect for the quantum dynamics of a single particle in the plane under the influence of an oscillating homogeneous electric and a constant perpendicular magnetic field. We prove that the electron cyclotron resonance is insensitive to impurity potentials.

Joachim Asch; Olivier Bourget; Cdric Meresse

2014-12-30T23:59:59.000Z

344

Ultra-high-frequency chaos in a time-delay electronic device with band-limited feedback  

E-Print Network [OSTI]

Ultra-high-frequency chaos in a time-delay electronic device with band-limited feedback Lucas- dynamical electronic device. It consists of a transistor-based nonlinearity, commercially of such a device, we explore the dynamics of an electronic circuit that consists of a simple transistor

Illing, Lucas

345

Optimization For Grade Transitions In Polyethylene Solution Polymerization  

E-Print Network [OSTI]

Optimization For Grade Transitions In Polyethylene Solution Polymerization Jun Shi1, Intan Hamdan2 Engineering Carnegie Mellon University 2The Dow Chemical Company #12;Dynamic Optimization Models Grade Transition for LLDPE · Continuous Stirred-Tank Reactor (CSTR) (represents two actual processes) · Assume

Grossmann, Ignacio E.

346

Flow dynamics and solute transport in unsaturated rock fractures  

E-Print Network [OSTI]

Experiment 2.3, n-dodecane and PCE, were dyed with 0.5 gILfluoroscein dye n-Dodecane(c) PCE(c) (a) 1.002 x 10- 3 1.002seepage of (a) n-dodecane and (b) PCE into the initially dry

Su, G.W.

2011-01-01T23:59:59.000Z

347

Flow dynamics and solute transport in unsaturated rock fractures  

SciTech Connect (OSTI)

Rock fractures play an important role in flow and contaminant transport in fractured aquifers, production of oil from petroleum reservoirs, and steam generation from geothermal reservoirs. In this dissertation, phenomenological aspects of flow in unsaturated fractures were studied in visualization experiments conducted on a transparent replica of a natural, rough-walled rock fracture for inlet conditions of constant pressure and flow rate over a range of angles of inclination. The experiments demonstrated that infiltrating liquid proceeds through unsaturated rock fractures along non-uniform, localized preferential flow paths. Even in the presence of constant boundary conditions, intermittent flow was a persistent flow feature observed, where portions of the flow channel underwent cycles of snapping and reforming. Two modes of intermittent flow were observed, the pulsating blob mode and the rivulet snapping mode. A conceptual model for the rivulet snapping mode was proposed and examined using idealized, variable-aperture fractures. The frequency of intermittent flow events was measured in several experiments and related to the capillary and Bond numbers to characterize this flow behavior.

Su, G. W.

1999-10-01T23:59:59.000Z

348

Low-Cost Solutions for Dynamic Window Material  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10IO1OP001Long-Termpaul_fini@cree.com CREECummins

349

ITP Aluminum: Aluminum Industry Vision: Sustainable Solutions for a Dynamic  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe U.S. Department ofIOWA1999) | Department ofWorld | Department

350

Controlling Graphene's Electronic Structure  

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

Controlling Graphene's Electronic Structure Print Wednesday, 25 April 2007 00:00 Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has...

351

Bearwall Energy Efficient Solutions  

E-Print Network [OSTI]

CATEE Conference November 20, 2014 ENERGY EFFICIENT SOLUTIONS ESL-KT-14-11-06 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Brief History of Bearwall Who We Are: ? Manuel Sovero ? Luis Osorio Energy Conservation... Experience: ESL-KT-14-11-06 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Energy Programs ESL-KT-14-11-06 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Bearwall Methodology Introduction...

Sovero,M.

2014-01-01T23:59:59.000Z

352

Cyanide Solution | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases onOrganization FY 2012 FYCustomer-Comments SignCyanide Solution

353

Electron Cloud Effects in Accelerators  

SciTech Connect (OSTI)

Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

Furman, M.A.

2012-11-30T23:59:59.000Z

354

Review: Greenhouse Solutions with Sustainable Energy  

E-Print Network [OSTI]

Solutions with Sustainable Energy By Mark DiesendorfSolutions with Sustainable Energy. Sydney, NSW: University

Hamilton-Smith, Elery

2009-01-01T23:59:59.000Z

355

Electromagnetic space-time crystals. III. Dispersion relations for partial solutions  

E-Print Network [OSTI]

Partial solutions of the Dirac equation describing an electron motion in electromagnetic crystals created by plane waves with linear and circular polarizations are treated. It is shown that the electromagnetic crystal formed by circularly polarized waves possesses the spin birefringence.

G. N. Borzdov

2014-10-21T23:59:59.000Z

356

Hollow cylinder dynamic pressurization and radial flow through permeability tests for cementitous materials  

E-Print Network [OSTI]

pressurization test is a potential solution for measuring concrete permeability. The hollow cylinder dynamic pressurization (HDP) test is compared with the radial flow through (RFT) test and the solid cylinder dynamic pressurization (SDP) test to assess...

Jones, Christopher Andrew

2009-05-15T23:59:59.000Z

357

Statistics as a dynamical attractor  

E-Print Network [OSTI]

It is demonstrated that any statistics can be represented by an attractor of the solution to a corresponding systen of ODE coupled with its Liouville equation. Such a non-Newtonian representation allows one to reduce foundations of statistics to better established foundations of ODE. In addition to that, evolution to the attractor reveals possible micro-mechanisms driving random events to the final distribution of the corresponding statistical law. Special attention is concentrated upon the power law and its dynamical interpretation: it is demonstrated that the underlying dynamics supports a " violent reputation" of the power law statistics.

Michail Zak

2012-08-30T23:59:59.000Z

358

Standing electromagnetic solitons in hot ultra-relativistic electron-positron plasmas  

SciTech Connect (OSTI)

Using a one-dimensional self-consistent fluid model, we investigate standing relativistic bright solitons in hot electron-positron plasmas. The positron dynamics is taken into account. A set of nonlinear coupled differential equations describing the evolution of electromagnetic waves in fully relativistic two-fluid plasma is derived analytically and solved numerically. As a necessary condition for the existence of standing solitons the system should be relativistic. For the case of ultra-relativistic plasma, we investigate non-drifting bright solitary waves. Detailed discussions of the acceptable solutions are presented. New single hump non-trivial symmetric solutions for the scalar potential were found, and single and multi-nodal symmetric and anti-symmetric solutions for the vector potential are presented. It is shown that for a fixed value of the fluid velocity excited modes with more zeros in the profile of the vector potential show a higher magnitude for the scalar potential. An increase in the plasma fluid velocity also increases the magnitude of the scalar potential. Furthermore, the Hamiltonian and the first integral of the system are given.

Heidari, E., E-mail: ehphys75@iaubushehr.ac.ir [Department of Sciences, Bushehr Branch, Islamic Azad University, Bushehr (Iran, Islamic Republic of); Aslaninejad, M. [Plasma Physics Research Centre, Science and Research Branch, Islamic Azad University, P.O. Box 14665-678, Tehran (Iran, Islamic Republic of)] [Plasma Physics Research Centre, Science and Research Branch, Islamic Azad University, P.O. Box 14665-678, Tehran (Iran, Islamic Republic of); Eshraghi, H. [Physics Department, Iran University of Science and Technology (IUST), P.O. Box 1684613114, Tehran (Iran, Islamic Republic of)] [Physics Department, Iran University of Science and Technology (IUST), P.O. Box 1684613114, Tehran (Iran, Islamic Republic of); Rajaee, L. [Department of Physics, Faculty of Science, University of Qom, Qom (Iran, Islamic Republic of)] [Department of Physics, Faculty of Science, University of Qom, Qom (Iran, Islamic Republic of)

2014-03-15T23:59:59.000Z

359

Kinetic simulations and reduced modeling of longitudinal sideband instabilities in non-linear electron plasma waves  

SciTech Connect (OSTI)

Kinetic Vlasov simulations of one-dimensional finite amplitude Electron Plasma Waves are performed in a multi-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate ? and quasi- wavenumber ?k, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are successfully compared against numerical and analytical solutions to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] for the Trapped Particle Instability (TPI). A model recently suggested by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)], which in addition to the TPI accounts for the so-called Negative Mass Instability because of a more detailed representation of the trapped particle dynamics, is also studied and compared with simulations.

Brunner, S., E-mail: stephan.brunner@epfl.ch; Hausammann, L. [Centre de Recherches en Physique des Plasmas, Association Euratom-Confdration Suisse, Ecole Polytechnique Fdrale de Lausanne, CRPP-PPB, CH-1015 Lausanne (Switzerland); Berger, R. L., E-mail: berger5@llnl.gov; Cohen, B. I. [Lawrence Livermore National Laboratory, University of California, P.O. Box 808, Livermore, California 94551 (United States); Valeo, E. J. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)

2014-10-15T23:59:59.000Z

360

Electronics, Electrical Engineering  

E-Print Network [OSTI]

SCHOOL OF Electronics, Electrical Engineering and Computer Science IS IN YOUR HANDS THE FUTURE #12;SCHOOL OF Electronics, Electrical Engineering and Computer Science2 CAREERS IN ELECTRONICS, ELECTRICAL Belfast. Ranked among the top 100 in the world for Electrical and Electronic Engineering (QS World

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


361

ELECTRONIC CHARTS INTRODUCTION  

E-Print Network [OSTI]

199 CHAPTER 14 ELECTRONIC CHARTS INTRODUCTION 1400. The Importance of Electronic Charts Since. Electronic charts automate the process of integrating real-time positions with the chart display and allow is expected to take and plot a fix every three minutes. An electronic chart system can do it once per second

New Hampshire, University of

362

Electron Beam Energy Chirp Control with a Rectangular Corrugated Structure at the Linac Coherent Light Source  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Electron beam energy chirp is an important parameter that affects the bandwidth and performance of a linac-based, free-electron laser. In this paper we study the wakefields generated by a beam passing between at metallic plates with small corrugations, and then apply such a device as a passive dechirper for the Linac Coherent Light Source (LCLS) energy chirp control with a multi-GeV and femtosecond electron beam. Similar devices have been tested in several places at relatively low energies (#24;100 MeV) and with relatively long bunches (> 1ps). In the parameter regime of the LCLS dechirper, with the corrugation size similar to the gap between the plates, the analytical solutions of the wakefields are no longer applicable, and we resort to a #12;field matching program to obtain the wakes. Based on the numerical calculations, we #12;fit the short-range, longitudinal wakes to simple formulas, valid over a large, useful parameter range. Finally, since the transverse wakefields - both dipole and quadrupole-are strong, we compute and include them in beam dynamics simulations to investigate the error tolerances when this device is introduced in the LCLS.

Zhang, Zhen; Bane, Karl; Ding, Yantao; Huang, Zhirong; Iverson, Richard; Maxwell, Timothy; Stupakov, Gennady; Wang, Lanfa

2015-01-30T23:59:59.000Z

363

Development of an (e,2e) electron momentum spectroscopy apparatus using an ultrashort pulsed electron gun  

SciTech Connect (OSTI)

An (e,2e) apparatus for electron momentum spectroscopy (EMS) has been developed, which employs an ultrashort-pulsed incident electron beam with a repetition rate of 5 kHz and a pulse duration in the order of a picosecond. Its instrumental design and technical details are reported, involving demonstration of a new method for finding time-zero. Furthermore, EMS data for the neutral Ne atom in the ground state measured by using the pulsed electron beam are presented to illustrate the potential abilities of the apparatus for ultrafast molecular dynamics, such as by combining EMS with the pump-and-probe technique.

Yamazaki, M.; Kasai, Y.; Oishi, K.; Nakazawa, H.; Takahashi, M. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

2013-06-15T23:59:59.000Z

364

Single molecule junctions, where a molecule with its perfect chemical reproducibility and versatility is the active part of an electronic device,  

E-Print Network [OSTI]

and versatility is the active part of an electronic device, are a bottom-up solution to the miniaturization quest of modern electronics. Quantum dot molecules (QDM) represent a top-down one. A QDM is composed of two studied the influence of electron-electron and electron-phonon interaction on the transport

Schubart, Christoph

365

Dynamic response of guyed towers  

E-Print Network [OSTI]

guyed towers. A parametric study was conducted using eigen analysis to determine the effects of consistent mass, geometric stiffness and P-Delta gravity loads. Time domain solutions were obtained by direct integration for motion due to regular Stokes... guyed tower 2 References to guyed tower dynamic analysis 4 Effect of mass formulation on tower natural periods. 5 P-Delta effect on fundamental period. 6 Effect of axial compression on the 1st & 2nd mode. 7 Geometric stiffness effect on natural...

Gillcrist, Mark Christopher

2012-06-07T23:59:59.000Z

366

Single Pass Electron Cooling Simulations for MEIC  

SciTech Connect (OSTI)

Cooling of medium energy protons is critical for the proposed Jefferson Lab Medium Energy Ion Collider (MEIC). We present simulations of electron cooling of protons up to 60 GeV. In the beam frame in which the proton and electrons are co-propagating, their motion is non-relativistic. We use a binary collision model which treats the cooling process as the sum of a large number of two-body collisions which are calculated exactly. This model can treat even very close collisions between an electron and ion with high accuracy. We also calculate dynamical friction using a delta-f PIC model. The code VSim (formerly Vorpal) is used to perform the simulations. We compare the friction rates with that obtained by a 3D integral over electron velocities which is used by BETACOOL.

Bell, G. I. [Tech-X Corp.; Pogorelov, I. V. [Tech-X Corp.; Schwartz, B. T. [Tech-X Corp.; Zhang, Yuhong [JLAB; Zhang, He [JLAB

2013-12-01T23:59:59.000Z

367

ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE SOLAR WIND  

SciTech Connect (OSTI)

A plausible mechanism responsible for producing asymmetric electron velocity distribution functions in the solar wind is investigated by means of one-dimensional electrostatic particle-in-cell (PIC) simulation. A recent paper suggests that the variation in the ion-to-electron temperature ratio influences the nonlinear wave-particle dynamics such that it results in the formation of asymmetric distributions. The present PIC code simulation largely confirms this finding, but quantitative differences between the weak turbulence formalism and the present PIC simulation are also found, suggesting the limitation of the analytical method. The inter-relationship between the asymmetric electron distribution and the ion-to-electron temperature ratio may be a new useful concept for the observation.

Rha, Kicheol; Ryu, Chang-Mo [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)] [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Yoon, Peter H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)] [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)

2013-09-20T23:59:59.000Z

368

Parallel electric fields in the upward current region of the aurora: Numerical solutions  

E-Print Network [OSTI]

Parallel electric fields in the upward current region of the aurora: Numerical solutions R. E Direct observations of the parallel electric field by the Fast Auroral Snapshot satellite and the Polar of the properties of the observed electric fields, electron distributions, and ion distributions. The solutions

California at Berkeley, University of

369

Dynamics-dependent symmetries in Newtonian mechanics  

E-Print Network [OSTI]

We exhibit two symmetries of one-dimensional Newtonian mechanics whereby a solution is built from the history of another solution via a generally nonlinear and complex potential-dependent transformation of the time. One symmetry intertwines the square roots of the kinetic and potential energies and connects solutions of the same dynamical problem (the potential is an invariant function). The other symmetry connects solutions of different dynamical problems (the potential is a scalar function). The existence of corresponding conserved quantities is examined using Noethers theorem and it is shown that the invariant-potential symmetry is correlated with energy conservation. In the Hamilton-Jacobi picture the invariant-potential transformation provides an example of a field-dependent symmetry in point mechanics. It is shown that this transformation is not a symmetry of the Schroedinger equation.

Peter Holland

2014-09-19T23:59:59.000Z

370

E-Print Network 3.0 - accelerated molecular dynamics Sample Search...  

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

77 Summary: . The molecular synchrotron1 is analogous to charged-particle accelerators. It borrows the techniques of high... electronic potentials governing the dynamics...

371

Zeldovich flow on cosmic vacuum background new exact nonlinear analytical solution  

E-Print Network [OSTI]

A new exact nonlinear Newtonian solution for a plane matter flow superimposed on the isotropic Hubble expansion is reported. The dynamical effect of cosmic vacuum is taken into account. The solution describes the evolution of nonlinear perturbations via gravitational instability of matter and the termination of the perturbation growth by anti-gravity of vacuum at the epoch of transition from matter domination to vacuum domination. On this basis, an `approximate' 3D solution is suggested as an analog of the Zeldovich ansatz.

Chernin, A D; Starikova, S V; Chernin, Arthur D.; Nagirner, Dmitrij I.; Starikova, Svetlana V.

2001-01-01T23:59:59.000Z

372

Quasi-linear analysis of the extraordinary electron wave destabilized by runaway electrons  

SciTech Connect (OSTI)

Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the EXEL instability for a range of different plasma parameters using a model runaway distribution function valid for highly relativistic runaway electron beams produced primarily by the avalanche process. Simulations show a rapid pitch-angle scattering of the runaway electrons in the high energy tail on the 1001000??s time scale. Due to the wave-particle interaction, a modification to the synchrotron radiation spectrum emitted by the runaway electron population is foreseen, exposing a possible experimental detection method for such an interaction.

Pokol, G. I.; Kmr, A.; Budai, A. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Budapest (Hungary); Stahl, A.; Flp, T. [Department of Applied Physics, Chalmers University of Technology, Gteborg (Sweden)

2014-10-15T23:59:59.000Z

373

Spurious Solutions in the Multiband Effective Mass Theory Applied to Low Dimensional Nanostructures  

E-Print Network [OSTI]

solutions, low dimensional semiconductor nanostructures 1 Introduction The electronic structure calculation.01.07-06.07.07 2 and to bridge modelling scales [27, 26]. One such theory, derived with the application, that is the low-dimensional (semiconductor) nanostructures where the motion of electrons is restricted, forcing

374

"Dark energy" as conformal dynamics of space  

E-Print Network [OSTI]

The exact solution for dynamic of conform-flat space homogeneous since dynamic equation is given. Conform mode of space metric changing in Global time theory has negative energy density. Swap of energy to this mode from another ones lead to increasing of Universe homogeneity although probability of this swap from local objects is negligibly small. Conform mode is corresponding to "dark energy" in observation astronomy.

D. Burlankov

2006-10-23T23:59:59.000Z

375

Electron localization in solid acetonitrile.  

SciTech Connect (OSTI)

Electron localization in the bulk condensed phases of acetonitrile differs drastically from the corresponding processes that take place in water and aliphatic alcohols. In particular, electron capture following the ionization of liquid and solid acetonitrile yields well-defined radical anions in place of the largely structureless solvated and trapped electrons characteristic of irradiated solutions and rigid glasses. This is remarkable given the many similarities that exist not only between the intrinsic properties of these individual solvent molecules, such as polarity, but also in their cooperative capacity to function as solvents. Here, with the aid of detailed experimental and computational studies, we examine on a fundamental level what gives rise to such a sharp contrast in the behavior of these alkyl cyanides as compared to water and alcohols. EPR and optical spectra, and ab initio calculations on the radical anions are used together with diffraction data for the crystal structures to demonstrate that electron attachment to nitrile molecules in the crystalline state results in a significant bending of the linear CCN moiety. Moreover, in the formation of the dimer anions, which only takes place in certain crystalline phases, it is determined that the intermolecular bonding occurs between the cyanide carbons in an antiparallel arrangement. A staggered structure for the dimer anion in {alpha}-acetonitrile is then suggested, in which there is a nearly coplanar arrangement with the two bent CCN fragments. The resulting structure accounts for the observed EPR parameters, the position of the UV-vis absorption band, and the trends observed in the vibronic progressions for the four H/D isotopomers. The dimer radical anion in a-acetonitrile retains the same orientation and symmetry as that of the preexisting neutral {l_brace}CH{sub 3}CN{r_brace}{sub 2} pairs in this crystal despite the resulting changes in molecular geometry and in the translational coordinates for the cyanide carbons as the two acetonitrile molecules come together. We suggest that dimer anions of nitriles can form only in the phases where such 'antiparallel' pairs occur, including liquid systems; otherwise, the electron remains attached to a single molecule, as in {beta}-acetonitrile. Because electron capture by water or alcohol molecules in the condensed phase appears to require larger molecular clusters, the contrast between the behavior of these solvents and acetonitrile is attributable to the relative ease with which acetonitrile molecules in the crystal or solvent can undergo valence-electron attachment via their accessible low-lying {pi}* orbitals.

Shkrob, I. A.; Takeda, K.; Williams, F.; Chemistry; Univ. of Tennessee

2002-10-03T23:59:59.000Z

376

Harsh environments electronics : downhole applications.  

SciTech Connect (OSTI)

The development and operational sustainment of renewable (geothermal) and non-renewable (fossil fuel) energy resources will be accompanied by increasingly higher costs factors: exploration and site preparation, operational maintenance and repair. Increased government oversight in the wake of the Gulf oil spill will only add to the cost burden. It is important to understand that downhole conditions are not just about elevated temperatures. It is often construed that military electronics are exposed to the upper limit in terms of extreme service environments. Probably the harshest of all service conditions for electronics and electrical equipment are those in oil, gas, and geothermal wells. From the technology perspective, advanced materials, sensors, and microelectronics devices are benefificial to the exploration and sustainment of energy resources, especially in terms of lower costs. Besides the need for the science that creates these breakthroughs - there is also a need for sustained engineering development and testing. Downhole oil, gas, and geothermal well applications can have a wide range of environments and reliability requirements: Temperature, Pressure, Vibration, Corrosion, and Service duration. All too frequently, these conditions are not well-defifined because the application is labeled as 'high temperature'. This ambiguity is problematic when the investigation turns to new approaches for electronic packaging solutions. The objective is to develop harsh environment, electronic packaging that meets customer requirements of cost, performance, and reliability. There are a number of challenges: (1) Materials sets - solder alloys, substrate materials; (2) Manufacturing process - low to middle volumes, low defect counts, new equipment technologies; and (3) Reliability testing - requirements documents, test methods and modeling, relevant standards documents. The cost to develop and sustain renewable and non-renewable energy resources will continue to escalate within the industry. Downhole electronics can provide a very cost-effective approach for well exploration and sustainment (data logging). However, the harsh environments are a 'game-changer' in terms defining materials, assembly processes and the long-term reliability of downhole electronic systems. The system-level approach will enable the integration of each of these contributors - materials, processes, and reliability - in order to deliver cost-effective electronics that meet customer requirements.

Vianco, Paul Thomas

2011-03-01T23:59:59.000Z

377

Chaos in an ion-channel free-electron laser with realistic helical wiggler  

SciTech Connect (OSTI)

Chaotic behavior of an electron motion in a free-electron laser with realistic helical wiggler and ion-channel guiding is studied using Poincare surface-of-section maps. The effects of a realistic electron beam density on chaotic electron dynamics are investigated by considering an electron beam with Gaussian density profile in radial distance. The effects of self-fields on chaotic electron dynamics are investigated for different Gaussian beam parameters, and the results are compared with those of uniform electron beam. It is shown that the electron chaotic behavior can be controlled by changing the Gaussian beam parameter. Also, the chaotic behavior can be controlled by increasing the ion-channel and/or the electron beam densities.

Esmaeilzadeh, Mahdi [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of); Taghavi, Amin [Department of Applied Science, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of)

2012-11-15T23:59:59.000Z

378

Modal aerosol dynamics modeling  

SciTech Connect (OSTI)

The report presents the governing equations for representing aerosol dynamics, based on several different representations of the aerosol size distribution. Analytical and numerical solution techniques for these governing equations are also reviewed. Described in detail is a computationally efficient numerical technique for simulating aerosol behavior in systems undergoing simultaneous heat transfer, fluid flow, and mass transfer in and between the gas and condensed phases. The technique belongs to a general class of models known as modal aerosol dynamics (MAD) models. These models solve for the temporal and spatial evolution of the particle size distribution function. Computational efficiency is achieved by representing the complete aerosol population as a sum of additive overlapping populations (modes), and solving for the time rate of change of integral moments of each mode. Applications of MAD models for simulating aerosol dynamics in continuous stirred tank aerosol reactors and flow aerosol reactors are provided. For the application to flow aerosol reactors, the discussion is developed in terms of considerations for merging a MAD model with the SIMPLER routine described by Patankar (1980). Considerations for incorporating a MAD model into the U.S. Environmental Protection Agency's Regional Particulate Model are also described. Numerical and analytical techniques for evaluating the size-space integrals of the modal dynamics equations (MDEs) are described. For multimodal logonormal distributions, an analytical expression for the coagulation integrals of the MDEs, applicable for all size regimes, is derived, and is within 20% of accurate numerical evaluation of the same moment coagulation integrals. A computationally efficient integration technique, based on Gauss-Hermite numerical integration, is also derived.

Whitby, E.R.; McMurry, P.H.; Shankar, U.; Binkowski, F.S.

1991-02-01T23:59:59.000Z

379

Crystal and electronic structures and linear optics of strontium pyroborate  

SciTech Connect (OSTI)

The compound Sr{sub 2}B{sub 2}O{sub 5} has been synthesized by high temperature solution reaction. It crystallizes in the monoclinic space group P2{sub 1}/c with cell dimensions a = 7.719(4), b = 5.341(1), c = 11.873(2) {angstrom}, {beta} = 92.71(2){degree}, V = 488.9(3) {angstrom}{sup 3}, and Z = 4, D{sub calc} = 3.76 g/cm{sup 3}. The structure comprises SrO{sub 7} and SrO{sub 6} polyhedra and B{sub 2}O{sub 5} groups. The electronic structure has been calculated by the INDO/S method for this compound, and the dynamic refractive indices have been obtained in terms of INDO/SCI following combination with the sum-over-states method. The calculated energy gap is 4.26 eV between the upper valence band and lower conduction band, and the calculated average refractive index is 1.791 at a wavelength of 1.065 {micro}m. The charge transfers from O{sup 2{minus}} anion orbitals to Sr{sup 2+} cation orbitals make the significant contributions to linear polarizability in terms of analyses of atomic state density contributing to the valence and conduction bands.

Lin, Q.S.; Cheng, W.D.; Chen, J.T.; Huang, J.S. [Chinese Academy of Sciences, Fuzhou, Fujian (China). Fujian Inst. of Research on the Structure of Matter] [Chinese Academy of Sciences, Fuzhou, Fujian (China). Fujian Inst. of Research on the Structure of Matter

1999-04-01T23:59:59.000Z

380

Bump formation in the runaway electron tail  

E-Print Network [OSTI]

Runaway electrons are generated in a magnetized plasma when the parallel electric field exceeds a critical value. For such electrons with energies typically reaching tens of MeV, the Abraham-Lorentz-Dirac (ALD) radiation force, in reaction to the synchrotron emission, is significant and can be the dominant process limiting the electron acceleration. The effect of the ALD-force on runaway electron dynamics in a homogeneous plasma is investigated using the relativistic finite-difference Fokker-Planck codes LUKE [Decker & Peysson, Report EUR-CEA-FC-1736, Euratom-CEA, (2004)] and CODE [Landreman et al, Comp. Phys. Comm. 185, 847 (2014)]. Under the action of the ALD force, we find that a bump is formed in the tail of the electron distribution function if the electric field is sufficiently large. We also observe that the energy of runaway electrons in the bump increases with the electric field amplitude, while the population increases with the bulk electron temperature. The presence of the bump divides the elec...

Decker, J; Flp, T

2015-01-01T23:59:59.000Z

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


381

NSTAR (Electric)- Business Solutions Program  

Broader source: Energy.gov [DOE]

The Business Solutions Program offers NSTAR's non-residential customers incentives for a variety of energy efficient retrofit and new construction projects. Prescriptive rebates are available for...

382

Is Nuclear Energy the Solution?  

E-Print Network [OSTI]

009-0270-y Is Nuclear Energy the Solution? Milton H. Saier &in the last 50 years, nuclear energy subsidies have totaledadministration, the Global Nuclear Energy Partnership (GNEP)

Saier, Milton H.; Trevors, Jack T.

2010-01-01T23:59:59.000Z

383

Enhanced safeguards via solution monitoring  

SciTech Connect (OSTI)

Solution monitoring is defined as the essentially continuous monitoring of solution level, density, and temperature in all tanks in the process that contain, or could contain, safeguards-significant quantities of nuclear material. This report describes some of the enhancements that solution monitoring could make to international safeguards. The focus is on the quantifiable benefits of solution monitoring, but qualitatively, solution monitoring can be viewed as a form of surveillance. Quantitatively, solution monitoring can in some cases improve diversion detection probability. For example, the authors show that under certain assumptions, solution monitoring can be used to reduce the standard deviation of the annual material balance, {sigma}{sub MB}, from approximately 17 kg to approximately 4 kg. Such reduction in {sigma}{sub MB} will not always be possible, as they discuss. However, in all cases, solution monitoring would provide assurance that the measurement error models are adequate so that one has confidence in his estimate of {sigma}{sub MB}. Some of the results in this report were generated using data that were simulated with prototype solution monitoring software that they are developing. An accompanying document describes that software.

Burr, T.; Wangen, L.

1996-09-01T23:59:59.000Z

384

A new ONERA-CNES Slot Electron Model A. Sicard-Piet1  

E-Print Network [OSTI]

A new ONERA-CNES Slot Electron Model A. Sicard-Piet1 , D. Boscher1 , D. Lazaro1 , S. Bourdarie1 , G-- A new model of electron flux in the Slot Region has been developed at ONERA. This model is based the dynamics of electron flux in the slot region. Index terms- Energetic particles-Slot region-Radiation belts

385

Symbolic dynamics  

E-Print Network [OSTI]

This chapter presents some of the links between automata theory and symbolic dynamics. The emphasis is on two particular points. The first one is the interplay between some particular classes of automata, such as local automata and results on embeddings of shifts of finite type. The second one is the connection between syntactic semigroups and the classification of sofic shifts up to conjugacy.

Bal, M -P; Eilers, S; Perrin, D

2010-01-01T23:59:59.000Z

386

Dynamics of empty homogeneous isotropic three-dimensional spaces  

E-Print Network [OSTI]

It is shown that there are seven types of solutions described in the framework of general relativity theory (GRT), the dynamics of empty homogeneous isotropic three-dimensional spaces. Solution of the equations of GRT, which describes the dynamics of a homogeneous isotropic universe, in the limiting case of vanishingly small effect of matter on the metric properties of space must go to one of them.

A. V. Klimenko; V. A. Klimenko

2012-02-28T23:59:59.000Z

387

On isotropic metric of Schwarzschild solution of Einstein equation  

E-Print Network [OSTI]

The known static isotropic metric of Schwarzschild solution of Einstein equation cannot cover with the range of r<2MG, a new isotropic metric of Schwarzschild solution is obtained. The new isotropic metric has the characters: (1) It is dynamic and periodic. (2) It has infinite singularities of the spacetime. (3) It cannot cover with the range of 0

T. Mei

2006-10-24T23:59:59.000Z

388

High conductivity electrolyte solutions and rechargeable cells incorporating such solutions  

DOE Patents [OSTI]

This invention relates generally to electrolyte solvents for use in liquid or rubbery polymer electrolyte solutions as are used, for example, in electrochemical devices. More specifically, this invention relates to sulfonyl/phospho-compound electrolyte solvents and sulfonyl/phospho-compound electrolyte solutions incorporating such solvents. 9 figs.

Angell, C.A.; Zhang, S.S.; Xu, K.

1998-10-20T23:59:59.000Z

389

Matter & Energy Electronics  

E-Print Network [OSTI]

See also: Matter & Energy Electronics· Detectors· Technology· Construction· Sports Science Electronic Tongue Tastes Wine Variety, Vintage (Aug. 12, 2008) -- You don't need a wine expert to Advance

Suslick, Kenneth S.

390

Catalac free electron laser  

DOE Patents [OSTI]

A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.

Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

391

Neutrinos in the Electron  

E-Print Network [OSTI]

We will show that one half of the rest mass of the electron is equal to the sum of the rest masses of electron neutrinos and that the other half of the rest mass of the electron is given by the energy in the sum of electric oscillations. With this composition we can explain the rest mass, the electric charge, the spin and the magnetic moment of the electron.

E. L. Koschmieder

2006-09-26T23:59:59.000Z

392

Energy Storage & Power Electronics 2008 Peer Review - Power Electronic...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Power Electronics (PE) Systems Presentations Energy Storage & Power Electronics 2008 Peer Review - Power Electronics (PE) Systems Presentations The 2008 Peer Review Meeting for the...

393

Dark Energy and Electrons  

E-Print Network [OSTI]

In the light of recent developments in Dark Energy, we consider the electron in a such a background field and show that at the Compton wavelength the electron is stable, in that the Cassini inward pressure exactly counterbalances the outward Coulomb repulsive pressure thus answering a problem of the earlier electron theory.

Burra G. Sidharth

2008-08-05T23:59:59.000Z

394

Better Buildings Residential Program Solution Center Demonstration...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Program Solution Center Demonstration Webinar Transcript Better Buildings Residential Program Solution Center Demonstration Webinar Transcript The Better Buildings Residential...

395

Conference Agenda: Residential Energy Efficiency Solutions 2012...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Conference Agenda: Residential Energy Efficiency Solutions 2012 Conference Agenda: Residential Energy Efficiency Solutions 2012 Presents conference agenda including a general...

396

Presentation: Better Buildings Residential Program Solution Center...  

Energy Savers [EERE]

Presentation: Better Buildings Residential Program Solution Center Presentation: Better Buildings Residential Program Solution Center Presentation: Better Buildings Residential...

397

Better Buildings Residential Program Solution Center Demonstration...  

Energy Savers [EERE]

Better Buildings Residential Program Solution Center Demonstration Webinar Better Buildings Residential Program Solution Center Demonstration Webinar Demonstration webinar slides...

398

Dynamics of clusters and molecules in contact with an environment  

E-Print Network [OSTI]

(embedded, deposited) Fundamental studies on mechanisms (irradiation, deposition) (Nano) Contacts with insulators (ionic crystals, rare gases...) Low energy dynamics (optical response, deposition) Laser irradiation #12;Time Dependent Density Functional Theory (TDDFT) Ensemble of orbitals (1 electron

Giraud, Olivier

399

Influence of the dynamical image potential on the rainbows in ion channeling through short carbon nanotubes  

SciTech Connect (OSTI)

We investigate the influence of the dynamic polarization of the carbon valence electrons on the angular distributions of protons channeled through short (11,9) single-wall carbon nanotubes at speeds of 3 and 5 a.u. (corresponding to the proton energies of 0.223 and 0.621 MeV), with the nanotube length varied from 0.1 to 0.3 {mu}m. The dynamic image force on protons is calculated by means of a two-dimensional hydrodynamic model for the nanotube's dielectric response, whereas the repulsive interaction with the nanotube's cylindrical wall is modeled by a continuum potential based on the Doyle-Turner interatomic potential. The angular distributions of channeled protons are generated by a computer simulation method using the numerical solution of the proton equations of motion in the transverse plane. Our analysis shows that the inclusion of the image interaction causes qualitative changes in the proton deflection function, giving rise to a number of rainbow maxima in the corresponding angular distribution. We propose that observations of those rainbow maxima could be used to deduce detailed information on the relevant interaction potentials, and consequently to probe the electron distribution inside carbon nanotubes.

Borka, D.; Petrovic, S.; Neskovic, N. [Laboratory of Physics (010), Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia and Montenegro); Mowbray, D. J.; Miskovic, Z. L. [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)

2006-06-15T23:59:59.000Z

400

Toroidal solutions in Horava Gravity  

E-Print Network [OSTI]

Recently a new four-dimensional non relativistic renormalizable theory of gravity was proposed by Horava. This gravity reduces to Einstein gravity at large distances. In this paper by using the new action for gravity we present different toroidal solutions to the equations of motion. Our solutions describe the near horizon geometry with slow rotating parameter.

Ahmad Ghodsi

2011-02-24T23:59:59.000Z

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


401

Remote power -- Integrated, customer oriented solutions  

SciTech Connect (OSTI)

Throughout its history, BP Solar has focused strongly on the production of integrated power solutions to it`s customers, using photovoltaics as the central, but not unique, technology. This paper discusses the customer driven development of two new generation hybrid power systems, one AC the other DC. Both involve the combination of renewable energy with a conventional power source in a fully integrated system, as well as providing remote electronic system access, advanced data and event logging, and comprehensive computer graphic analysis software. The first is a DC system providing power to telecommunication authorities in the Asian-Pacific region, the second is generating abundant high quality AC power for Australian domestic users.

Jordan, D.; Twidell, M.; Patel, J.; Teofilo, F.; Soin, R. [BP Solar Australia, Brookvale, New South Wales (Australia)

1994-12-31T23:59:59.000Z

402

JLAB Electron Driver Capabilities  

SciTech Connect (OSTI)

Several schemes have been proposed for adding a positron beam option at the Continuous Electron Beam Facility (CEBAF) at Jefferson Laboratory (JLAB). They involve using a primary beam of electrons or gamma rays striking a target to produce a positron beam. At JLAB electron beams are produced and used in two different accelerators, CEBAF and the JLAB FEL (Free Electron Laser). Both have low emittance and energy spread. The CEBAF beam is polarized. The FEL beam is unpolarized but the injector can produce a higher current electron beam. In this paper we describe the characteristics of these beams and the parameters relevant for positron production.

Kazimi, Reza [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2009-09-02T23:59:59.000Z

403

Flavor Dynamics  

E-Print Network [OSTI]

The purpose of BRAHMS is to survey the dynamics of relativistic heavy ion (as well as pp and d-A) collisions over a very wide range of rapidity and transverse momentum. The sum of these data may give us a glimpse of the initial state of the system, its transverse and longitudinal evolution and how the nature of the system changes with time. Here I will concentrate on the origin and dynamics of the light flavors, i.e. the creation and transport of the up, down and strange quarks. The results presented here are certainly not the end of the story. It is my hope that in a few years new detectors will reveal the rapidity dependence of the charm and bottom quarks.

Michael Murray; for the BRAHMS Collaboration

2007-10-24T23:59:59.000Z

404

Complex Dynamics of Real Nanosystems: Fundamental Paradigm for Nanoscience and Nanotechnology  

E-Print Network [OSTI]

Structure and dynamics of real nanosystems emerge from the unreduced solution of the underlying interaction problem. It has the property of dynamic multivaluedness giving genuine dynamic randomness and complexity (physics/9806002, physics/0405063). Chaoticity is irreducibly high in nanoscale systems and underlies exponentially high efficiency of their real, complex-dynamic operation (physics/0211071). Applications include real, dynamically chaotic quantum devices, nano-biotechnology, and genetics.

Andrei P. Kirilyuk

2004-12-16T23:59:59.000Z

405

Effects of oxygen reduction on nickel deposition from unbuffered aqueous solutions. 2: Characterization of the electrode interface in electrodeposition  

SciTech Connect (OSTI)

Contrary to the reactive electrodeposition of cobalt, porous nickel is not easily produced by electrodeposition from neutral aqueous solutions in the presence of dissolved oxygen. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) examination of the electrode surface detected the presence of a highly stable metal hydroxide layer of the same characteristics as precipitated Ni(OH){sub 2}. The hydroxide layer inhibits the nucleation of nickel nuclei and increases the irreversibility in electrodeposition. For reactive deposition to result in a porous deposit, the hydroxide layer should have only moderate stability so that it can be continuously removed and reinstated by interfacial chemical and electrochemical reactions. The surface Ni(OH){sub 2} formed in neutral solutions lacks the reactivity for such dynamism. Nonetheless, the stability of surface Ni(OH){sub 2} could be lowered by increasing the acidity of the deposition medium. Careful pH control seems to be a requirement for nickel reactive electrodeposition to produce porous metal deposits.

Cui, C.Q.; Lee, J.Y.; Lin, J.; Tan, K.L. [National Univ. of Singapore (Singapore)

1995-04-01T23:59:59.000Z

406

Separated spin-up and spin-down quantum hydrodynamics of degenerated electrons: spin-electron acoustic wave appearance  

E-Print Network [OSTI]

Quantum hydrodynamic (QHD) model of charged spin-1/2 particles contains physical quantities defined for all particles of a species including particles with spin-up and with spin-down. Different population of states with different spin direction is included in the spin density (magnetization). In this paper we derive a QHD model, which separately describes spin-up electrons and spin-down electrons. Hence we consider electrons with different projection of spin on the preferable direction as two different species of particles. We show that numbers of particles with different spin direction do not conserve. Hence the continuity equations contain sources of particles. These sources are caused by the interactions of spins with magnetic field. Terms of similar nature arise in the Euler equation. We have that z-projection of the spin density is no longer an independent variable. It is proportional to difference between concentrations of electrons with spin-up and electrons with spin-down. In terms of new model we consider propagation of waves in magnetized plasmas of degenerate electrons and motionless ions. We show that new form of QHD equations gives all solutions obtained from traditional form of QHD equations with no distinguish of spin-up and spin-down states. But it also reveals a sound-like solution we call the spin-electron acoustic wave. Coincidence of most solutions is expected since we started derivation with the same basic equation.

Pavel A. Andreev

2014-05-04T23:59:59.000Z

407

Dynamics of dark energy  

E-Print Network [OSTI]

In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards understanding the nature of dark energy. We review the observational evidence for the current accelerated expansion of the universe and present a number of dark energy models in addition to the conventional cosmological constant, paying particular attention to scalar field models such as quintessence, K-essence, tachyon, phantom and dilatonic models. The importance of cosmological scaling solutions is emphasized when studying the dynamical system of scalar fields including coupled dark energy. We study the evolution of cosmological perturbations allowing us to confront them with the observation of the Cosmic Microwave Background and Large Scale Structure and demonstrate how it is possible in principle to reconstruct the equation of state of dark energy by also using Supernovae Ia observational data. We also discuss in detail the nature of tracking solutions in cosmology, particle physics and braneworld models of dark energy, the nature of possible future singularities, the effect of higher order curvature terms to avoid a Big Rip singularity, and approaches to modifying gravity which leads to a late-time accelerated expansion without recourse to a new form of dark energy.

Edmund J. Copeland; M. Sami; Shinji Tsujikawa

2006-06-16T23:59:59.000Z

408

Electron transfer reactions in microporous solids  

SciTech Connect (OSTI)

Basic thrust the research program involves use of microporous solids (zeolites, clays, layered and tunnel structure oxide semiconductors) as organizing media for artificial photosynthetic systems. Purpose of the microporous solid is twofold. First, it induces spatial organization of photoactive and electroactive components (sensitizers, semiconductor particles, electron relays, and catalysts) at the solid-solution interface, enhancing the quantum efficiency of charge separation and separating physically the ultimate electron donor and acceptor in the electron transport chain. Second, since the microcrystalline solid admits only molecules of a certain charge and size, it is possible to achieve permanent charge separation by sieving chemical photoproducts (e.g., H[sub 2] and I[sub 3][sup [minus

Mallouk, T.E.

1993-01-01T23:59:59.000Z

409

Average dynamics of a finite set of coupled phase oscillators  

SciTech Connect (OSTI)

We study the solutions of a dynamical system describing the average activity of an infinitely large set of driven coupled excitable units. We compared their topological organization with that reconstructed from the numerical integration of finite sets. In this way, we present a strategy to establish the pertinence of approximating the dynamics of finite sets of coupled nonlinear units by the dynamics of its infinitely large surrogate.

Dima, Germn C., E-mail: gdima@df.uba.ar; Mindlin, Gabriel B. [Laboratorio de Sistemas Dinmicos, IFIBA y Departamento de Fsica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabelln 1, Ciudad Universitaria, Buenos Aires (Argentina)] [Laboratorio de Sistemas Dinmicos, IFIBA y Departamento de Fsica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabelln 1, Ciudad Universitaria, Buenos Aires (Argentina)

2014-06-15T23:59:59.000Z

410

Propagation of three-dimensional electron-acoustic solitary waves  

SciTech Connect (OSTI)

Theoretical investigation is carried out for understanding the properties of three-dimensional electron-acoustic waves propagating in magnetized plasma whose constituents are cold magnetized electron fluid, hot electrons obeying nonthermal distribution, and stationary ions. For this purpose, the hydrodynamic equations for the cold magnetized electron fluid, nonthermal electron density distribution, and the Poisson equation are used to derive the corresponding nonlinear evolution equation, Zkharov-Kuznetsov (ZK) equation, in the small- but finite- amplitude regime. The ZK equation is solved analytically and it is found that it supports both solitary and blow-up solutions. It is found that rarefactive electron-acoustic solitary waves strongly depend on the density and temperature ratios of the hot-to-cold electron species as well as the nonthermal electron parameter. Furthermore, there is a critical value for the nonthermal electron parameter, which decides whether the electron-acoustic solitary wave's amplitude is decreased or increased by changing various plasma parameters. Importantly, the change of the propagation angles leads to miss the balance between the nonlinearity and dispersion; hence, the localized pulses convert to explosive/blow-up pulses. The relevance of this study to the nonlinear electron-acoustic structures in the dayside auroral zone in the light of Viking satellite observations is discussed.

Shalaby, M.; El-Sherif, L. S. [Faculty of Science, Department of Physics, Ain Shams University, Cairo (Egypt); El-Labany, S. K. [Theoretical Physics Group, Faculty of Science, Department of Physics, Mansoura University, Damietta Branch, New Damietta 34517 (Egypt); Sabry, R. [Theoretical Physics Group, Faculty of Science, Department of Physics, Mansoura University, Damietta Branch, New Damietta 34517 (Egypt); Physics Department, College of Science and Humanitarian Studies, Alkharj University, Alkharj (Saudi Arabia)

2011-06-15T23:59:59.000Z

411

Quasi Sturmian Basis in Two-Electron Continuum Problems  

E-Print Network [OSTI]

A new type of basis functions is proposed to describe a two-electron continuum which arises as a final state in electron-impact ionization and double photoionization of atomic systems. We name these functions, which are calculated in terms of the recently introduced Quasi Sturmian functions, Convoluted Quasi Sturmian functions (CQS). By construction, the CQS functions look asymptotically like a six-dimensional spherical wave. The driven equation describing an $(e, 3e)$ process on helium in the framework of the Temkin-Poet model has been solved numerically using expansions on the basis CQS functions. The convergence behavior of the solution has been examined as the size of the basis has been increased. The calculations show that the convergence rate is significantly improved by introducing a phase factor corresponding the electron-electron interaction into the basis functions. Such a modification of the boundary conditions leads to appreciable change in the magnitude of the solution.

A. S. Zaytsev; L. U. Ancarani; S. A. Zaytsev

2015-03-12T23:59:59.000Z

412

Single trap dynamics in electrolyte-gated Si-nanowire field effect transistors  

SciTech Connect (OSTI)

Liquid-gated silicon nanowire (NW) field effect transistors (FETs) are fabricated and their transport and dynamic properties are investigated experimentally and theoretically. Random telegraph signal (RTS) fluctuations were registered in the nanolength channel FETs and used for the experimental and theoretical analysis of transport properties. The drain current and the carrier interaction processes with a single trap are analyzed using a quantum-mechanical evaluation of carrier distribution in the channel and also a classical evaluation. Both approaches are applied to treat the experimental data and to define an appropriate solution for describing the drain current behavior influenced by single trap resulting in RTS fluctuations in the Si NW FETs. It is shown that quantization and tunneling effects explain the behavior of the electron capture time on the single trap. Based on the experimental data, parameters of the single trap were determined. The trap is located at a distance of about 2?nm from the interface Si/SiO{sub 2} and has a repulsive character. The theory of dynamic processes in liquid-gated Si NW FET put forward here is in good agreement with experimental observations of transport in the structures and highlights the importance of quantization in carrier distribution for analyzing dynamic processes in the nanostructures.

Pud, S.; Li, J.; Offenhusser, A.; Vitusevich, S. A., E-mail: s.vitusevich@fz-juelich.de [Peter Grnberg Institute (PGI-8), Forschungszentrum Jlich, 52425 Jlich (Germany); Gasparyan, F. [Peter Grnberg Institute (PGI-8), Forschungszentrum Jlich, 52425 Jlich (Germany); Department of Semiconductor Physics and Microelectronics, Yerevan State University, 1 Alex Manoogian St., 0025 Yerevan (Armenia); Petrychuk, M. [Radiophysics Faculty, T. Shevchenko National University of Kyiv, 60 Volodymyrska St., 01601 Kyiv (Ukraine)

2014-06-21T23:59:59.000Z

413

ICFA Beam Dynamics Newsletter  

SciTech Connect (OSTI)

The Collider-Accelerator Department at Brookhaven National Laboratory is building a high-brightness 500 mA capable Energy Recovery Linac (ERL) as one of its main R&D thrusts towards eRHIC, the polarized electron - hadron collider as an upgrade of the operating RHIC facility. The ERL is in final assembly stages, with injection commisioning starting in October 2012. The objective of this ERL is to serve as a platform for R&D into high current ERL, in particular issues of halo generation and control, Higher-Order Mode (HOM) issues, coherent emissions for the beam and high-brightness, high-power beam generation and preservation. The R&D ERL features a superconducting laser-photocathode RF gun with a high quantum efficiency photoccathode served with a load-lock cathode delivery system, a highly damped 5-cell accelerating cavity, a highly flexible single-pass loop and a comprehensive system of beam instrumentation. In this ICFA Beam Dynamics Newsletter article we will describe the ERL in a degree of detail that is not usually found in regular publications. We will discuss the various systems of the ERL, following the electrons from the photocathode to the beam dump, cover the control system, machine protection etc and summarize with the status of the ERL systems.

Ben-Zvi I.; Kuczewski A.; Altinbas, Z.; Beavis, D.; Belomestnykh,; Dai, J. et al

2012-07-01T23:59:59.000Z

414

Ghost spinors, shadow electrons and the Deutsch Multiverse  

E-Print Network [OSTI]

In this article a new solution of the Einstein-Dirac's equations is presented. There are ghost spinors, i.e. the stress-energy tensor is equal to zero and the current of these fields is non-zero vector. Last the ghost neutrino was found. These ghost spinors and shadow particles of Deutsch are identified. And in result the ghost spinors have a physical interpretation and solutions of the field equations for shadow electrons as another shadow particles are found.

Elena V. Palesheva

2001-08-05T23:59:59.000Z

415

Dynamic Positioning Simulator Dynamic Positioning Simulator  

E-Print Network [OSTI]

Simulator 5 / 24 #12;Dynamic Positioning Simulator Dynamic Positioning Why Dynamic Positioning? Advantages Dynamic Positioning: No tugboats needed; Offshore set-up is quick; Power saving; Precision situations more on Ship: Wind Force Fw = 1 2 air V 2 rw CXw (rw )AT 1 2 air V 2 rw CYw (rw )AL Mw = 1 2 air V 2 rw CMw (rw

Vuik, Kees

416

Interferences of real trajectories and the emergence of quantum features in electron-atom scattering in a strong laser field  

SciTech Connect (OSTI)

Using the example of electron-atom scattering in a strong laser field, it is shown that the oscillatory structure of the scattered electron spectrum can be explained as a consequence of the interference of the real electron trajectories in terms of Feynman's path integral. While in previous work on quantum-orbit theory the complex solutions of the saddle-point equations were considered, we show here that for the electron-atom scattering with much simpler real solutions a satisfactory agreement with the strong-field-approximation results can be achieved. Real solutions are applicable both for the direct (low-energy) and the rescattering (high-energy) plateau in the scattered electron spectrum. In between the plateaus and beyond the rescattering cutoff good results can be obtained using the complex (quantum) solutions and the uniform approximation. The interference of real solutions is related to the recent attosecond double-slit experiment in time.

Cerkic, A. [Federal Meteorological Institute, Bardakcije 12, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

2006-03-15T23:59:59.000Z

417

The discontinuous dynamics and non-autonomous chaos  

E-Print Network [OSTI]

A multidimensional chaos is generated by a special initial value problem for the non-autonomous impulsive differential equation. The existence of a chaotic attractor is shown, where density of periodic solutions, sensitivity of solutions and existence of a trajectory dense in the set of all orbits are observed. The chaotic properties of all solutions are discussed. An appropriate example is constructed, where the intermittency phenomenon is indicated. The results of the paper are illustrating that impulsive differential equations may play a special role in the investigation of the complex behavior of dynamical systems, different from that played by continuous dynamics.

M. U. Akhmet

2007-12-31T23:59:59.000Z

418

Dynamics of the photocyclization of cis-stilbene to dihydrophenanthrene  

E-Print Network [OSTI]

-adiabatically. However, there is only very limited information about the excited state dynamics along the reaction electronic excitation, vibrational mode excitation, intra-molecular vibrational energy redis- tributionDynamics of the photocyclization of cis-stilbene to dihydrophenanthrene YUSHENG DOU and ROLAND E

Allen, Roland E.

419

Kerr-Newman solution as a Dirac particle  

E-Print Network [OSTI]

For m^2 < a^2 + q^2, with m, a, and q respectively the source mass, angular momentum per unit mass, and electric charge, the Kerr--Newman (KN) solution of Einstein's equation reduces to a naked singularity of circular shape, enclosing a disk across which the metric components fail to be smooth. By considering the Hawking and Ellis extended interpretation of the KN spacetime, it is shown first that, similarly to the electron-positron system, this solution presents four inequivalent classical states. Next, it is shown that due to the topological structure of the extended KN spacetime it does admit states with half-integral angular momentum. This last property is corroborated by the fact that, under a rotation of the space coordinates, those inequivalent states transform into themselves only after a 4pi rotation. As a consequence, it becomes possible to naturally represent them in a Lorentz spinor basis. The state vector representing the whole KN solution is then constructed, and its evolution is shown to be governed by the Dirac equation. The KN solution can thus be consistently interpreted as a model for the electron-positron system, in which the concepts of mass, charge and spin become connected with the spacetime geometry. Some phenomenological consequences of the model are explored.

H. I. Arcos; J. G. Pereira

2004-01-19T23:59:59.000Z

420

RELATIVISTIC GLOBAL SOLUTIONS OF NEUTRINO-DOMINATED ACCRETION FLOWS  

SciTech Connect (OSTI)

Neutrino-dominated accretion flows (NDAFs) around rotating stellar-mass black holes are plausible candidates for the central engines of gamma-ray bursts (GRBs). We investigate one-dimensional global solutions of NDAFs, taking into account general relativity in the Kerr metric, neutrino physics, and nucleosynthesis more precisely than previous works. We calculate 16 solutions with different characterized accretion rates and black hole spins to exhibit the radial distributions of various physical properties in NDAFs. We confirm that the electron degeneracy has important effects in NDAFs and we find that the electron fraction is about 0.46 in the outer region for all 16 solutions. From the perspective of the mass fraction, free nucleons, {sup 4}He, and {sup 5}6Fe dominate in the inner, middle, and outer regions, respectively. The influence of neutrino trapping on the annihilation is of importance for the superhigh accretion ( M-dot =10 M{sub sun} s{sup -1}) and most of the 16 solutions have an adequate annihilation luminosity for GRBs.

Xue Li; Liu Tong; Gu Weimin; Lu Jufu, E-mail: tongliu@xmu.edu.cn [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China)

2013-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic electron solutions" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


421

Electronic Friction Dominates Hydrogen Hot-Atom Relaxation on Pd(100) M. Blanco-Rey,1,2  

E-Print Network [OSTI]

initio molecular dynamics simulations that include a friction force to account for the energy transfer February 2014; published 14 March 2014) We study the dynamics of transient hot H atoms on Pd(100 to the electronic system. We find that the excitation of electron-hole pairs is the main channel for energy

Muiño, Ricardo Díez

422

Laser spectroscopy and dynamics of transient species  

SciTech Connect (OSTI)

The goal of this program is to study the vibrational and electronic spectra and excited state dynamics of a number of transient sulfur and oxygen species. A variety of supersonic jet techniques, as well as high resolution FT-IR and intracavity dye laser spectroscopy, have been applied to these studies.

Clouthier, D.J. [Univ. of Kentucky, Lexington (United States)

1993-12-01T23:59:59.000Z

423

Tunable Dirac Fermion Dynamics in Topological Insulators  

E-Print Network [OSTI]

Tunable Dirac Fermion Dynamics in Topological Insulators Chaoyu Chen1 , Zhuojin Xie1 , Ya Feng1, Beijing 100190, China. Three-dimensional topological insulators are characterized by insulating bulk state topological insulators. We have directly revealed signatures of the electron-phonon coupling and found

Wang, Wei Hua

424

Is Nuclear Energy the Solution?  

E-Print Network [OSTI]

10.1007/s11270-009-0270-y Is Nuclear Energy the Solution?MHS) attended a lecture on Nuclear Responsibility on theof the Alliance for Nuclear Responsibility. The information

Saier, Milton H.; Trevors, Jack T.

2010-01-01T23:59:59.000Z

425

Negative Energy Solutions and Symmetries  

E-Print Network [OSTI]

We revisit the negative energy solutions of the Dirac equation, which become relevant at very high energies and study several symmetries which follow therefrom. The consequences are briefly examined.

Burra G. Sidharth

2011-04-01T23:59:59.000Z

426

Solid state electron-hopping transport and frozen concentration gradients in a mixed valent viologen-tetraethylene oxide copolymer  

SciTech Connect (OSTI)

This paper describes electrochemistry and electron-hopping dynamics for a novel viologen-based redox polymer (poly-V{sup 2+}) formed from the copolymerization of tetraethylene glycol di-p-tosylate and 4,4{prime}-bipyridine. Current-potential responses and electron-hopping (i.e., self-exchange) rates have been measured for mixed valent films of poly-V{sup 2+} on interdigitated array electrodes contacted by tetrahydrofuran/acetonitrile/tetrabutylammonium perchlorate electrolyte solution and as dry mixed valent films in vacuum or dry nitrogen. Electron transfer rates vary with the mixed valency composition of poly-V{sup 2+/+} films (judging film composition from the electrolysis potential with the Nernst equation) according to bimolecular reaction theory for solvent-wetted but less well for dry films. Current-potential characteristics are also reported for mixed valent films that contain concentration gradients of the poly-V{sup 2+} and poly-V{sup +} redox states, which we attempt to freeze into place by drying the film under a gradient-generating potential bias so as to immobilize the film`s counterions. Current transients at room and reduced (-30{degree}C) temperature show that the room-temperature responses of films containing concentration gradients are sensitive to small changes in poly-V{sup 2+/+} oxidation state at the electrode/polymer interfaces. 24 refs., 9 figs., 1 tab.

Terrill, R.H.; Hutchison, J.E.; Murray, R.W. [Univ. of North Carolina, Chapel Hill, NC (United States)] [Univ. of North Carolina, Chapel Hill, NC (United States)

1997-02-27T23:59:59.000Z

427

Field emission electron source  

DOE Patents [OSTI]

A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

2000-01-01T23:59:59.000Z

428

Ceramic Electron Multiplier  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

Comby, G.

1996-10-01T23:59:59.000Z

429

Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural transformations: Molecular dynamics study  

E-Print Network [OSTI]

Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural dynamics simulations of a 20 nm Au film irradiated with 200 fs laser pulses of different intensity in time-resolved x-ray and electron diffraction experiments. Three processes are found to be responsible

Zhigilei, Leonid V.

430

Isomorphic classical molecular dynamics model for an excess electronin a supercritical fluid  

SciTech Connect (OSTI)

Ring polymer molecular dynamics (RPMD) is used to directly simulate the dynamics of an excess electron in a supercritical fluid over a broad range of densities. The accuracy of the RPMD model is tested against numerically exact path integral statistics through the use of analytical continuation techniques. At low fluid densities, the RPMD model substantially underestimates the contribution of delocalized states to the dynamics of the excess electron. However, with increasing solvent density, the RPMD model improves, nearly satisfying analytical continuation constraints at densities approaching those of typical liquids. In the high density regime, quantum dispersion substantially decreases the self-diffusion of the solvated electron. In this regime where the dynamics of the electron is strongly coupled to the dynamics of the atoms in the fluid, trajectories that can reveal diffusive motion of the electron are long in comparison to {beta}{h_bar}.

Miller III, Thomas F.

2008-08-04T23:59:59.000Z

431

Environment assisted electron capture  

E-Print Network [OSTI]

Electron capture by {\\it isolated} atoms and ions proceeds by photorecombination. In this process a species captures a free electron by emitting a photon which carries away the excess energy. It is shown here that in the presence of an {\\it environment} a competing non-radiative electron capture process can take place due to long range electron correlation. In this interatomic (intermolecular) process the excess energy is transferred to neighboring species. The asymptotic expression for the cross section of this process is derived. We demonstrate by explicit examples that under realizable conditions the cross section of this interatomic process can clearly dominate that of photorecombination.

Kirill Gokhberg; Lorenz S. Cederbaum

2009-11-09T23:59:59.000Z

432

Radiological Electron Microprobe | EMSL  

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

from the Hanford Site provide complementary data to ongoing activities in EMSL's microfluidics and Subsurface Flow and Transport capabilities. User Portal Name: Electron...

433

Electronic decoherence time for non-Born-Oppenheimer trajectories  

SciTech Connect (OSTI)

An expression is obtained for the electronic decoherence time of the reduced density electronic matrix in mixed quantum-classical molecular-dynamics simulations. The result is obtained by assuming that decoherence is dominated by the time dependence of the overlap of minimum-uncertainty packets and then maximizing the rate with respect to the parameters of the wave packets. The expression for the decay time involves quantities readily available in non-Born-Oppenheimer molecular-dynamics simulations, and it is shown to have a reasonable form when compared with two other formulas for the decay time that have been previously proposed.

Jasper, Ahren W.; Truhlar, Donald G. [Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States)

2005-08-08T23:59:59.000Z

434

Spatially resolved dynamic structure factor of finite systems from molecular dynamics simulations  

SciTech Connect (OSTI)

The dynamical response of metallic clusters up to 10{sup 3} atoms is investigated using the restricted molecular dynamics simulations scheme. Exemplarily, a sodium like material is considered. Correlation functions are evaluated to investigate the spatial structure of collective electron excitations and the optical response of laser-excited clusters. In particular, the spectrum of bilocal correlation functions shows resonances representing different modes of collective excitations inside the nano plasma. The spatial structure, the resonance energy, and the width of the eigenmodes have been investigated for various values of electron density, temperature, cluster size, and ionization degree. Comparison with bulk properties is performed and the dispersion relation of collective excitations is discussed.

Raitza, Thomas; Roepke, Gerd; Reinholz, Heidi; Morozov, Igor [Institut fuer Physik, Universitaet Rostock, D-18051 Rostock (Germany); Institut fuer Theoretische Physik, Johannes-Kepler-Universitaet Linz, A-4040 Linz, Austria and Institute of Physics, University of Western Australia, Perth, WA 6009 (Australia); Joint Institute for High Temperatures of RAS, 13 Izhorskaya Street, Building 2, Moscow RU-125412 (Russian Federation)

2011-09-15T23:59:59.000Z

435

Electron Transfer Between Colloidal ZnO Nanocrystals  

SciTech Connect (OSTI)

Colloidal ZnO nanocrystals capped with dodecylamine and dissolved in toluene can be charged photochemically to give stable solutions in which electrons are present in the conduction bands of the nanocrystals. These conduction-band electrons are readily monitored by EPR spectroscopy, with g* values that correlate with the nanocrystal sizes. Mixing a solution of charged small nanocrystals (e{sub CB}{sup -}:ZnO-S) with a solution of uncharged large nanocrystals (ZnO-L) caused changes in the EPR spectrum indicative of quantitative electron transfer from small to large nanocrystals. EPR spectra of the reverse reaction, e{sub CB}{sup -}:ZnO-L + ZnO-S, showed that electrons do not transfer from large to small nanocrystals. Stopped-flow kinetics studies monitoring the change in the UV bandedge absorption showed that reactions of 50 {micro}M nanocrystals were complete within the 5 ms mixing time of the instrument. Similar results were obtained for the reaction of charged nanocrystals with methyl viologen (MV{sup 2+}). These and related results indicate that the electron-transfer reactions of these colloidal nanocrystals are quantitative and very rapid, despite the presence of {approx}1.5 nm long dodecylamine capping ligands. These soluble ZnO nanocrystals are thus well-defined redox reagents suitable for studies of electron transfer involving semiconductor nanostructures.

Hayoun, Rebecca; Whitaker, Kelly M.; Gamelin, Daniel R.; Mayer, James M.

2011-03-30T23:59:59.000Z

436

SciTech Connect: A Solution for Solution-Produced [beta]-FeSe...  

Office of Scientific and Technical Information (OSTI)

A Solution for Solution-Produced beta-FeSe: Elucidating and Overcoming Factors that Prevent Superconductivity Citation Details In-Document Search Title: A Solution for...

437

Low Emittance Electron Beam Studies  

SciTech Connect (OSTI)

We have studied the properties of a low emittance electron beam produced by laser pulses incident onto an rf gun photocathode. The experiments were carried out at the A0 photoinjector at Fermilab. Such beam studies are necessary for fixing the design of new Linear Colliders as well as for the development of Free Electron Lasers. An overview of the A0 photoinjector is given in Chapter 1. In Chapter 2 we describe the A0 photoinjector laser system. A stable laser system is imperative for reliable photoinjector operation. After the recent upgrade, we have been able to reach a new level of stability in the pulse-to-pulse fluctuations of the pulse amplitude, and of the temporal and transverse profiles. In Chapter 3 we present a study of transverse emittance versus the shape of the photo-cathode drive-laser pulse. For that purpose a special temporal profile laser shaping device called a pulse-stacker was developed. In Chapter 4 we discuss longitudinal beam dynamics studies using a two macro-particle bunch; this technique is helpful in analyzing pulse compression in the magnetic chicane, as well as velocity bunching effects in the rf-gun and the 9-cell accelerating cavity. In Chapter 5 we introduce a proposal for laser acceleration of electrons. We have developed a laser functioning on the TEM*{sub 01} mode, a mode with a longitudinal electric field component which is suitable for such a process. Using this technique at energies above 40 MeV, one would be able to observe laser-based acceleration.

Tikhoplav, Rodion; /Rochester U.; ,

2006-04-01T23:59:59.000Z

438

Electronic Commerce Research, 3: 924 (2003) 2003 Kluwer Academic Publishers. Manufactured in the Netherlands.  

E-Print Network [OSTI]

, helal}@cise.ufl.edu Database Systems R&D Center, University of Florida, Gainesville, FL 32611-6125, USA [Alonso, 1; Grefen, 5; Lazcano, 9; Sheth, 14; Stricker, 15]; however, a good solution to support dynamic

Helal, Abdelsalam

439

Rate of decoherence for an electron weakly coupled to a phonon gas  

E-Print Network [OSTI]

We study the dynamics of an electron weakly coupled to a phonon gas. The initial state of the electron is the superposition of two spatially localized distant bumps moving towards each other, and the phonons are in a thermal state. We investigate the dynamics of the system in the kinetic regime and show that the time evolution makes the non-diagonal terms of the density matrix of the electron decay, destroying the interference between the two bumps. We show that such a damping effect is exponential in time, and the related decay rate is proportional to the total scattering cross section of the electron-phonon interaction.

Riccardo Adami; Laszlo Erdos

2008-02-08T23:59:59.000Z

440

Blackboard Agents for Mixed-Initiative Management of Integrated Process-Planning/Production-Scheduling Solutions Across the Supply Chain  

E-Print Network [OSTI]

Engineering Laboratory Raytheon Electronic Systems Raytheon Company Tewksbury MA 01876-0901 508.858.f5756 customized for and validated in the context of a large and highly dynamic machine shop at Raytheon's Andover

Sadeh, Norman M.

Note: This page contains sample records for the topic "dynamic electron solutions" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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441

Spherical Solutions in Einstein-Aether Theory: Static Aether and Stars  

E-Print Network [OSTI]

The time independent spherically symmetric solutions of General Relativity (GR) coupled to a dynamical unit timelike vector are studied. We find there is a three-parameter family of solutions with this symmetry. Imposing asymptotic flatness restricts to two parameters, and requiring that the aether be aligned with the timelike Killing field further restricts to one parameter, the total mass. These "static aether" solutions are given analytically up to solution of a transcendental equation. The positive mass solutions have spatial geometry with a minimal area 2-sphere, inside of which the area diverges at a curvature singularity occurring at an extremal Killing horizon that lies at a finite affine parameter along a radial null geodesic. Regular perfect fluid star solutions are shown to exist with static aether exteriors, and the range of stability for constant density stars is identified.

Christopher Eling; Ted Jacobson

2009-12-06T23:59:59.000Z

442

Electronic Mail Analysis Capability  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

Establishes the pilot program to test the Department of Energy (DOE) Electronic Mail Analysis Capability (EMAC), which will be used to monitor and analyze outgoing and incoming electronic mail (e-mail) from the National Nuclear Security Administration (NNSA) and DOE laboratories that are engaged in nuclear weapons design or work involving special nuclear material. No cancellation.

2001-01-08T23:59:59.000Z

443

Electrons and Mirror Symmetry  

SciTech Connect (OSTI)

The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

Kumar, Krishna (University of Massachusetts, Amherst) [University of Massachusetts, Amherst

2007-04-04T23:59:59.000Z

444

Multidimensional electron-photon transport with standard discrete ordinates codes  

SciTech Connect (OSTI)

A method is described for generating electron cross sections that are compatible with standard discrete ordinates codes without modification. There are many advantages of using an established discrete ordinates solver, e.g. immediately available adjoint capability. Coupled electron-photon transport capability is needed for many applications, including the modeling of the response of electronics components to space and man-made radiation environments. The cross sections have been successfully used in the DORT, TWODANT and TORT discrete ordinates codes. The cross sections are shown to provide accurate and efficient solutions to certain multidimensional electronphoton transport problems.

Drumm, C.R.

1995-12-31T23:59:59.000Z

445

Dynamic interaction potential and the scattering cross sections of the semiclassical plasma particles  

SciTech Connect (OSTI)

The dynamic model of the charged particles interaction in non-ideal semiclassical plasma is presented. This model takes into account the quantum mechanical diffraction effect and the dynamic screening effect. On the basis of the dynamic interaction potential, the electron scattering cross sections are investigated. Comparison with the results obtained on the basis of other models and conclusions were made.

Dzhumagulova, K. N.; Shalenov, E. O.; Gabdullina, G. L. [IETP, Al Farabi Kazakh National University, 71al Farabi Street, Almaty 050040 (Kazakhstan)

2013-04-15T23:59:59.000Z

446

Comment on ''Chaotic electron trajectories in an electromagnetic wiggler free-electron laser with ion-channel guiding'' [Phys. Plasmas 17, 093103 (2010)  

SciTech Connect (OSTI)

The chaotic electron dynamics in a free-electron laser with electromagnetic-wave wiggler and ion-channel has been recently reported by A. Taghavi et al.[Phys. Plasmas 17, 093103 (2010)]. We comment on the authors use of a set of initial condition that is not correct based on the dispersion relation and steady-state orbits.

Nasr, N.; Hasanbeigi, A. [Department of Physics and Institute for Plasma Research, Tarbiat Moallem University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)

2011-05-15T23:59:59.000Z

447

Propagation of a cloud of hot electrons through a plasma in the presence of Langmuir scattering by ambient density fluctuations  

SciTech Connect (OSTI)

Gas-dynamic theory is generalized to incorporate the effects of beam-driven Langmuir waves scattering off ambient density fluctuations, and the consequent effects on the propagation of a cloud of hot electrons in an inhomogeneous plasma. Assuming Langmuir scattering as the limit of nonlinear three-wave interactions with fluctuations that are weak, low-frequency, long-wavelength ion-sound waves, the net effect of scattering is equivalent to effective damping of the Langmuir waves. Under the assumption of self-similarity in the evolution of the beam and Langmuir wave distribution functions, gas-dynamic theory shows that the effects of Langmuir scattering on the beam distribution are equivalent to a perturbation in the injection profile of the beam. Analytical expressions are obtained for the height of the plateau of the beam distribution function, wave spectral number density, total wave and particle energy density, and the beam number density. The main results of gas-dynamic theory are then compared with simulation results from numerical solutions of quasilinear equations. The relaxation of the beam in velocity space is retarded in the presence of density fluctuations and the magnitude of the upper velocity boundary is less than that in the absence of fluctuations. There are four different regimes for the height of the plateau, corresponding to different stages of relaxation of the beam in velocity space. Moreover, Langmuir scattering results in transfer of electrons from moderate velocity to low velocity; this effect produces an enhancement in the beam number density at small distances near the injection site and a corresponding decrease at large distances. There are sharp decreases in the profiles of the beam and total wave energy densities, which are related to dissipation of energy at large phase velocities. Due to a slower velocity space diffusion of the beam distribution in the presence of scattering effects, the spatial width of the beam is reduced while its mean velocity of propagation increases slightly.

Foroutan, G. R.; Robinson, P. A.; Sobhanian, S.; Moslehi-Fard, M.; Li, B.; Cairns, I. H. [School of Physics, University of Sydney, NSW 2006, Sydney (Australia); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441 Maragha (Iran, Islamic Republic of) and Physics Department, Faculty of Science, Sahand University of Technology, 51335-1996 Tabriz (Iran); School of Physics, University of Sydney, NSW 2006, Sydney (Australia); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441 Maragha (Iran, Islamic Republic of) and Faculty of Physics, Tabriz University, Tabriz 51664 (Iran); Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of); School of Physics, University of Sydney, NSW 2006, Sydney (Australia)

2007-01-15T23:59:59.000Z

448

15718 J. Phys. Chem. 1995,99, 15718-15720 Energetics of Semiconductor ElectroddSolution Interfaces: EQCM Evidence for  

E-Print Network [OSTI]

Formation in the Titanium DioxiddAcetonitrile System L. Andrew Lyon and Joseph T. Hupp* Department-containing solutions of acetonitrile show that electron accumulationlayer formation is coupled directly shift of the flatband potential in acetonitrile, in comparison to aqueous solutions. More generally

449

Quantum mechanics of the free Dirac electrons and Einstein photons, and the Cauchy process  

E-Print Network [OSTI]

Fundamental solutions for the free Dirac electron and Einstein photon equations in position coordinates are constructed as matrix valued functionals on the space of bump functions. It is shown that these fundamental solutions are related by a unitary transform via the Cauchy distribution in imaginary time. We study the way the classical relativistic mechanics of the free particle comes from the quantum mechanics of the free Dirac electron.

A. A. Beilinson

2014-12-03T23:59:59.000Z

450

Predissociation dynamics of lithium iodide  

E-Print Network [OSTI]

The predissociation dynamics of lithium iodide (LiI) in the first excited A-state is investigated for molecules in the gas phase and embedded in helium nanodroplets, using femtosecond pump-probe photoionization spectroscopy. In the gas phase, the transient Li+ and LiI+ ion signals feature damped oscillations due to the excitation and decay of a vibrational wave packet. Based on high-level ab initio calculations of the electronic structure of LiI and simulations of the wave packet dynamics, the exponential signal decay is found to result from predissociation predominantly at the lowest avoided X-A potential curve crossing, for which we infer a coupling constant V=650(20) reciprocal cm. The lack of a pump-probe delay dependence for the case of LiI embedded in helium nanodroplets indicates fast droplet-induced relaxation of the vibrational excitation.

Schmidt, H; Stienkemeier, F; Bogomolov, A S; Baklanov, A V; Reich, D M; Skomorowski, W; Koch, C P; Mudrich, M

2015-01-01T23:59:59.000Z

451

Vorbeck Materials Corp. | Department of Energy  

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

Laboratory 333 likes Integrated Dynamic Electron Solutions, Inc., based in Belmont, California, uses Dynamic Transmission Electron Microscopes (DTEM) to enable imaging of...

452

Non-Born-Oppenheimer molecular dynamics of NaFH photodissociation Ahren W. Jaspera  

E-Print Network [OSTI]

Non-Born-Oppenheimer molecular dynamics of Na¯FH photodissociation Ahren W. Jaspera Combustion 20 November 2007 The accuracy of non-Born-Oppenheimer electronically nonadiabatic semiclassical are re- stricted to a single Born-Oppenheimer electronic state typi- cally, the ground electronic state

Truhlar, Donald G

453

Project Management Plan Solution Stabilization  

SciTech Connect (OSTI)

This plan presents the overall objectives, description, justification and planning for the Plutonium Finishing Plant (PFP) Solutions Stabilization subproject. The intent of this plan is to describe how this project will be managed and integrated with other facility stabilization and deactivation activities. This plan supplements the overall integrated plan presented in the Integrated Project Management Plan (IPMP) for the Plutonium Finishing Plant Stabilization and Deactivation Project, HNF-3617. This project plan is the top-level definitive project management document for the PFP Solution Stabilization subproject. It specifies the technical, schedule, requirements and the cost baselines to manage the execution of the Solution Stabilization subproject. Any deviations to the document must be authorized through the appropriate change control process.

SATO, P.K.

1999-08-31T23:59:59.000Z

454

Interested Parties - Energy Solutions | Department of Energy  

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

- Energy Solutions EnergySolutions.pdf More Documents & Publications Interested Parties - NRG Energy Interested Parties - Myriant Interested Parties - 1603 Program Discussion...

455

Funding Opportunity Webinar - Advancing Solutions To Improve...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Funding Opportunity Webinar - Advancing Solutions To Improve the Energy Efficiency of US Commercial Buildings Funding Opportunity Webinar - Advancing Solutions To Improve the...

456

Webinar Presentation: Energy Storage Solutions for Microgrids...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Presentation: Energy Storage Solutions for Microgrids (November 2012) Webinar Presentation: Energy Storage Solutions for Microgrids (November 2012) On November 7, 2012, Clean...

457

Blueprint for Sustainability - Sustainable Solutions for Every...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Blueprint for Sustainability - Sustainable Solutions for Every Consumer Blueprint for Sustainability - Sustainable Solutions for Every Consumer Highlights of Ford's near, mid, and...

458

Chemical structure and dynamics: Annual report 1993  

SciTech Connect (OSTI)

The Chemical Structure and Dynamics program responds to the need for a fundamental, molecular-level understanding of chemistry at the wide variety of environmentally-important interfaces. The research program is built around the established relationship between structure, thermodynamics, and kinetics. This research effort continues to evolve into a program of rigorous studies of fundamental molecular processes in model systems (e.g., well-characterized surfaces, single-component solutions, clusters, and biological molecules), and studies of complex systems found in the environment. Experimental studies of molecular and supramolecular structures and thermodynamics are key to understanding the nature of matter, and lead to direct comparison with computational results. Kinetic and mechanistic measurements, combined with real-time dynamics measurements of atomic and molecular motions during chemical reactions, provide for a molecular-level description of chemical reactions. The anticipated results of this work are the achievement of a quantitative understanding of chemical processes at complex interfaces, the development of new techniques for the detection and measurement of species at such interfaces, and the interpretation and extrapolation of the observations in terms of models of interfacial chemistry. The Chemical Structure and Dynamics research program includes five areas described in detail in this report: Reaction mechanisms at solid interfaces; Solution and solution interfaces; Structure and dynamics of biological systems; Analytical methods development; and atmospheric chemistry. Extended abstracts are presented for 23 studies.

Colson, S.D.

1994-07-01T23:59:59.000Z

459

Bremsstrahlung emission modelling and application to fast electron physics  

SciTech Connect (OSTI)

Measurements of fast electron bremsstrahlung (FEB) using hard X-ray (HXR) cameras provide a unique diagnostic for the fast electron dynamics, with resolution in space, time and energy. A synthetic HXR diagnostic is developed to calculate the distribution function and FEB emission, such that experimental results can be directly compared with simulations. Using this comparison, the role of fast electron radial transport in radio-frequency current drive is investigated. For two cases studied in this paper, the HXR emission is consistent with negligible radial transport, although in one case this is in disagreement with the measured driven current.

Decker, J.; Peysson, Y.; Artaud, J.-F.; Basiuk, V.; Ekedahl, A.; Mazon, D. [CEA, IRFM, F-13108 Saint Paul lez Durance (France); Coda, S.; Gnesin, S.; Goniche, M. [CRPP, EPFL, CH-1015 Lausanne (Switzerland); Sharma, P. K. [IPR, Bhat, Gandhinagar - 382428 (India)

2011-12-23T23:59:59.000Z

460

Competitive Dynamics of Web Sites  

E-Print Network [OSTI]

We present a dynamical model of web site growth in order to explore the effects of competition among web sites and to determine how they affect the nature of markets. We show that under general conditions, as the competition between sites increases, the model exhibits a sudden transition from a regime in which many sites thrive simultaneously, to a "winner take all market" in which a few sites grab almost all the users, while most other sites go nearly extinct. This prediction is in agreement with recent measurements on the nature of electronic markets.

Sebastian M. Maurer; Bernardo A. Huberman

2000-03-17T23:59:59.000Z

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


461

Cybersecurity Dynamics Shouhuai Xu  

E-Print Network [OSTI]

Cybersecurity Dynamics Shouhuai Xu Department of Computer Science, University of Texas at San Antonio ABSTRACT We explore the emerging field of Cybersecurity Dynamics, a candidate foundation for the Science of Cybersecurity. Keywords Cybersecurity dynamics, security model, security analysis 1

Xu, Shouhuai

462

Gravitational duality and rotating solutions  

SciTech Connect (OSTI)

We study how gravitational duality acts on rotating solutions, using the Kerr-NUT black hole as an example. After properly reconsidering how to take into account both electric (i.e. masslike) and magnetic (i.e. NUT-like) sources in the equations of general relativity, we propose a set of definitions for the dual Lorentz charges. We then show that the Kerr-NUT solution has nontrivial such charges. Further, we clarify in which respect Kerr's source can be seen as a mass M with a dipole of NUT charges.

Argurio, Riccardo; Dehouck, Francois [Physique Theorique et Mathematique and International Solvay Institutes, Universite Libre de Bruxelles, C.P. 231, 1050 Bruxelles (Belgium)

2010-03-15T23:59:59.000Z

463

Radiation from electrons in graphene in strong electric field  

E-Print Network [OSTI]

We study the interaction of electrons in graphene with the quantized electromagnetic field in the presence of an applied uniform electric field using the Dirac model of graphene. Electronic states are represented by exact solutions of the Dirac equation in the electric background, and amplitudes of first-order Feynman diagrams describing the interaction with the photon field are calculated for massive Dirac particles in both valleys. Photon emission probabilities from a single electron and from a many-electron system at the charge neutrality point are derived, including the angular and frequency dependence, and several limiting cases are analyzed. The pattern of photon emission at the Dirac point in a strong field is determined by an interplay between the nonperturbative creation of electron-hole pairs and spontaneous emission, allowing for the possibility of observing the Schwinger effect in measurements of the radiation emitted by pristine graphene under DC voltage.

N. Yokomizo

2014-05-05T23:59:59.000Z

464

Aerogels for electronics  

SciTech Connect (OSTI)

In addition to their other exceptional properties, aerogels also exhibit unusual dielectric and electronic properties due to their nano-sized structures and high porosities. For example, aerogels have the lowest dielectric constants measured for a solid material (having values approaching 1.0); they have exceptionally high dielectric resistivities and strengths (i.e., ability to insulate very high voltages); they exhibit low dielectric loss at microwave frequencies; and some aerogels are electrically conductive and photoconductive. These properties are being exploited to provide the next generation of materials for energy storage, low power consumption, and ultra-fast electronics. We are working toward adapting these unusual materials for microelectronic applications, particularly, making thin aerogel films for dielectric substrates and for energy storage devices such as supercapacitors. Measurements are presented in this paper for the dielectric and electronic properties of aerogels, including the dielectric constant, loss factor, dielectric and electrical conductivity, volume resistivity, and dielectric strength. We also describe methods to form and characterize thin aerogel films which are being developed for numerous