Sample records for dynamic electron solutions

  1. Proton-coupled electron transfer reactions in solution: Molecular dynamics with quantum transitions for model systems

    E-Print Network [OSTI]

    Hammes-Schiffer, Sharon

    Proton-coupled electron transfer reactions in solution: Molecular dynamics with quantum transitions A general minimal model for proton-coupled electron transfer PCET reactions in solution is presented. This model consists of three coupled degrees of freedom that represent an electron, a proton, and a solvent

  2. Integrated Dynamic Electron Solutions, Inc. | Department of Energy

    Energy Savers [EERE]

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed off Energy.gov.Energy02.pdf7 OPAMEnergy Innovation inInspectionIntegrated Dynamic Electron

  3. SOLUTION-PROCESSED INORGANIC ELECTRONICS

    E-Print Network [OSTI]

    Bakhishev, Teymur

    2011-01-01T23:59:59.000Z

    Solution-Processed Graphene Electronics,” Nano Letters, vol.applications,” Organic Electronics, vol. 12, no. 2, pp. 249-design in organic electronics by dual-gate technology,” in

  4. 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:...

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

    SciTech Connect (OSTI)

    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

    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.

  6. Ultrafast studies of solution dynamics

    SciTech Connect (OSTI)

    Woodruff, W.H.; Dyer, R.B. [Los Alamos National Lab., NM (United States); Callender, R.H. [City Univ. of New York, NY (United States). Dept. of Physics

    1997-10-01T23:59:59.000Z

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Fast chemical dynamics generally must be initiated photochemically. This limits the applicability of modern laser methods for following the structural changes that occur during chemical and biological reactions to those systems that have an electronic chromophore that has a significant yield of photoproduct when excited. This project has developed a new and entirely general approach to ultrafast initiation of reactions in solution: laser-induced temperature jump (T-jump). The results open entire new fields of study of ultrafast molecular dynamics in solution. The authors have demonstrated the T-jump technique on time scales of 50 ps and longer, and have applied it to study of the fast events in protein folding. They find that a general lifetime of alpha-helix formation is ca 100 ns, and that tertiary folds (in apomyoglobin) form in ca 100 {mu}s.

  7. Electronic Spectroscopy & Dynamics

    SciTech Connect (OSTI)

    Mark Maroncelli, Nancy Ryan Gray

    2010-06-08T23:59:59.000Z

    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.

  8. Solution of Large Eigenvalue Problems in Electronic Structure Calculations \\Lambda

    E-Print Network [OSTI]

    Stathopoulos, Andreas

    Solution of Large Eigenvalue Problems in Electronic Structure Calculations \\Lambda Y. Saad y , A the structural and electronic properties of complex systems is one of the outstanding problems in condensed external perturbations. For example, it may be desirable in certain cases to follow the dynamics of atoms/electrons

  9. Fissile solution dynamics: Student research

    SciTech Connect (OSTI)

    Hetrick, D.L.

    1994-09-01T23:59:59.000Z

    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.

  10. PIA - Savannah River Nuclear Solutions Electronic Safeguards...

    Energy Savers [EERE]

    System (E3S) PIA - Savannah River Nuclear Solutions Electronic Safeguards Security System (E3S) More Documents & Publications PIA - 10th International Nuclear Graphite...

  11. Structure, Charge Distribution, and Electron Hopping Dynamics...

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

    Charge Distribution, and Electron Hopping Dynamics in Magnetite (Fe3O4) (100) Surfaces from First Principles. Structure, Charge Distribution, and Electron Hopping Dynamics in...

  12. State-Dependent Electron Delocalization Dynamics at the Solute-Solvent Interface: Soft X-ray Absorption Spectroscopy and Ab Initio Calculations

    E-Print Network [OSTI]

    Bokarev, Sergey I; Suljoti, Edlira; Kühn, Oliver; Aziz, Emad F

    2013-01-01T23:59:59.000Z

    Non-radiative decay channels in the L-edge fluorescence spectra from transition metal-aqueous solutions give rise to spectral dips in X-ray transmission spectra. Their origin is unraveled here using partial and inverse partial fluorescence yields on the micro-jet combined with multi-reference ab initio electronic structure calculations. Comparing Fe2+, Fe3+, and Co2+ systems we demonstrate unequivocally that spectral dips are due to a state-dependent electron delocalization within the manifold of d-orbitals.

  13. Dynamic imaging with electron microscopy

    ScienceCinema (OSTI)

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2014-05-30T23:59:59.000Z

    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.

  14. Rotational Relaxation of Ionic Molecules in Electrolyte Solutions. Anisotropy Relaxation and Molecular Dynamics Study

    E-Print Network [OSTI]

    Kurnikova, Maria

    and the metal cation. Conductivity measure- ments and ab initio electronic structure calculations are used structure and the solute dynamics occur for ionic solute molecules. Both experimental4-10 and theoretical11 of experimental studies, ab initio electronic struc- ture, and molecular dynamics (MD) simulation is used

  15. Electronic Relaxation Dynamics in Coupled Metal Nanoparticles

    E-Print Network [OSTI]

    Scherer, Norbert F.

    of hot electrons for photoelectrochemical processes, including solar energy conversion or organic wasteElectronic Relaxation Dynamics in Coupled Metal Nanoparticles Mark J. Feldstein, Christine D

  16. Intermittent Single-Molecule Interfacial Electron Transfer Dynamics...

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

    Intermittent Single-Molecule Interfacial Electron Transfer Dynamics. Intermittent Single-Molecule Interfacial Electron Transfer Dynamics. Abstract: We report on single molecule...

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

    E-Print Network [OSTI]

    Yaron, David

    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

  18. Brownian Dynamics Simulation of Protein Solutions: Structural and Dynamical Properties

    SciTech Connect (OSTI)

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

    2010-12-01T23:59:59.000Z

    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.

  19. Packaging solution for VLSI electronic photonic chips

    E-Print Network [OSTI]

    Lee, Chieh-feng

    2007-01-01T23:59:59.000Z

    As the demand of information capacity grows, the adoption of optical technology will increase. The issue of resistance and capacitance is limiting the electronic transmission bandwidth while fiber optic delivers data at ...

  20. AdS String: Classical Solutions and Moduli Dynamics

    E-Print Network [OSTI]

    Antal Jevicki; Kewang Jin

    2010-01-29T23:59:59.000Z

    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.

  1. Electron dynamics in surface acoustic wave devices

    E-Print Network [OSTI]

    Thorn, Adam Leslie

    2009-10-13T23:59:59.000Z

    -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...

  2. Photoinduced electron transfer processes in homogeneous and microheterogeneous solutions

    SciTech Connect (OSTI)

    Whitten, D.G.

    1992-12-01T23:59:59.000Z

    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.

  3. Efficient electronic structure calculation for molecular ionization dynamics at high x-ray intensity

    E-Print Network [OSTI]

    Hao, Yajiang; Hanasaki, Kota; Son, Sang-Kil; Santra, Robin

    2015-01-01T23:59:59.000Z

    We present the implementation of an electronic-structure approach dedicated to ionization dynamics of molecules interacting with x-ray free-electron laser (XFEL) pulses. In our scheme, molecular orbitals for molecular core-hole states are represented by linear combination of numerical atomic orbitals that are solutions of corresponding atomic core-hole states. We demonstrate that our scheme efficiently calculates all possible multiple-hole configurations of molecules formed during XFEL pulses. The present method is suitable to investigate x-ray multiphoton multiple ionization dynamics and accompanying nuclear dynamics, providing essential information on the chemical dynamics relevant for high-intensity x-ray imaging.

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

    SciTech Connect (OSTI)

    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

    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.

  5. Hydration structure of salt solutions from ab initio molecular dynamics

    SciTech Connect (OSTI)

    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

    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.

  6. Electronic and structural dynamics in transition metal complexes...

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

    Electronic and structural dynamics in transition metal complexes - recent results from synchrotron and XFEL experiments Wednesday, March 4, 2015 - 3:00pm SLAC, Redtail Hawk...

  7. Probing attosecond electron dynamics at solid surfaces | Stanford...

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

    Probing attosecond electron dynamics at solid surfaces Wednesday, May 13, 2015 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Jrg Osterwalder, Department of Physics,...

  8. Dynamical Electron Mass in a Strong Magnetic Field

    E-Print Network [OSTI]

    S. -Y. Wang

    2008-01-28T23:59:59.000Z

    Motivated by recent interest in understanding properties of strongly magnetized matter, we study the dynamical electron mass generated through approximate chiral symmetry breaking in QED in a strong magnetic field. We reliably calculate the dynamical electron mass by numerically solving the nonperturbative Schwinger-Dyson equations in a consistent truncation within the lowest Landau level approximation. It is shown that the generation of dynamical electron mass in a strong magnetic field is significantly enhanced by the perturbative electron mass that explicitly breaks chiral symmetry in the absence of a magnetic field.

  9. Electrons and Phonons in amorphous Si: Deformation Potentials and Solutions of the Time Dependent Schrdinger Equation

    E-Print Network [OSTI]

    Drabold, David

    ]. The electronic structure calculations are based upon "FIREBALL96" of Sankey and co-workers [7]. Mat. Res. Soc of the electron dynamics of localized edge states in a-Si at room temperature by integrating the time dependent be computed by directly dealing with the electron dynamics from the time- dependent Schrödinger equation

  10. On the construction and properties of weak solutions describing dynamic cavitation

    E-Print Network [OSTI]

    Miroshnikov, Alexey

    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

  11. 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...

  12. Electronic and Magnetization Dynamics of Cobalt Substituted Iron Oxide Nanocrystals

    E-Print Network [OSTI]

    Chen, Tai-Yen

    2011-02-22T23:59:59.000Z

    to excite the weak absorption originating from the intervalence charge transfer transition (IVCT) between Fe2+ and Fe3+ ions of Fe3O4 nanocrystals. The timescale and corresponding relaxation processes of electronic relaxation dynamics of the excited IVCT...

  13. The dynamics of polymers in solution with hydrodynamic memory

    E-Print Network [OSTI]

    V. Lisy; J. Tothova; B. Brutovsky; A. V Zatovsky

    2005-09-15T23:59:59.000Z

    The theory of the dynamics of polymers in solution is developed coming from the hydrodynamic theory of the Brownian motion (BM) and the Rouse-Zimm (RZ) model. It is shown that the time correlation functions describing the polymer motion essentially differ from those in the previous RZ models based on the Einstein theory of BM. The MSD of the polymer coil is at short times proportional to t^2 (instead of t). At long times it contains additional (to the Einstein term) contributions, the leading of which is ~ t^{1/2}. The relaxation of the internal normal modes of the polymer differs from the traditional exponential decay. This is displayed in the tails of their correlation functions, the longest-lived being ~ t^{-3/2} in the Rouse limit and t^{-5/2} in the Zimm case when the hydrodynamic interaction is strong. It is discussed that the found peculiarities, in particular a slower diffusion of the coil, should be observable in dynamic scattering experiments. The dynamic structure factor and the first cumulant of the polymer coil are calculated. The theory is extended to the situation when the dynamics of the studied polymer is influenced by the presence of other polymers in dilute solution.

  14. Electron Cooling Dynamics progress update ( December 15, 2003)

    E-Print Network [OSTI]

    Electron Cooling Dynamics progress update ( December 15, 2003) A. Fedotov #12;Goals of the meeting cooling dynamics issues ­ we would like to get input on our present studies and understanding. 2. We would and benchmarking: Vorpal, SimCool and BetaCool ­ this morning 3. We started to study friction force with the Vorpal

  15. Structure and dynamics of aqueous solution of uranyl ions

    SciTech Connect (OSTI)

    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

    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 Å around the uranium atom, whereas the hydrogen atoms of water are distributed around the uranium atom with the major peak at around 3.0 Å. 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.

  16. Free electron in a laser field: The nonrelativistic solution

    E-Print Network [OSTI]

    C. Yuce

    2006-12-11T23:59:59.000Z

    Schrodinger equation for a charged particle interacting with the plane wave electromagnetic field is solved exactly. The exact analytic solution and the perturbative solution up to second order are compared.

  17. Electron Dynamics in Nanostructures in Strong Laser Fields

    SciTech Connect (OSTI)

    Kling, Matthias

    2014-09-11T23:59:59.000Z

    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.

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

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

    PIA - Savannah River Nuclear Solutions (SRNS) Human Resource Management System (HRMS) MOX Services Unclassified Information System PIA, National Nuclear Services Administration...

  19. aqueous solution electron: Topics by E-print Network

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

    and alternating current polarography of nitrobenzene in aqueous solutions and in acetonitrile. Open Access Theses and Dissertations Summary: ??The polarographic reduction of...

  20. Photoinduced electron transfer processes in homogeneous and microheterogeneous solutions

    SciTech Connect (OSTI)

    Whitten, D.G.

    1991-10-01T23:59:59.000Z

    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.

  1. A correlated-polaron electronic propagator: open electronic dynamics beyond the Born-Oppenheimer approximation

    E-Print Network [OSTI]

    John A. Parkhill; Thomas Markovich; David G. Tempel; Alan Aspuru-Guzik

    2012-10-02T23:59:59.000Z

    In this work we develop a theory of correlated many-electron dynamics dressed by the presence of a finite-temperature harmonic bath. The theory is based on the ab-initio Hamiltonian, and thus well-defined apart from any phenomenological choice of collective basis states or electronic coupling model. The equation-of-motion includes some bath effects non-perturbatively, and can be used to simulate line- shapes beyond the Markovian approximation and open electronic dynamics which are subjects of renewed recent interest. Energy conversion and transport depend critically on the ratio of electron-electron coupling to bath-electron coupling, which is a fitted parameter if a phenomenological basis of many-electron states is used to develop an electronic equation of motion. Since the present work doesn't appeal to any such basis, it avoids this ambiguity. The new theory produces a level of detail beyond the adiabatic Born-Oppenheimer states, but with cost scaling like the Born-Oppenheimer approach. While developing this model we have also applied the time-convolutionless perturbation theory to correlated molecular excitations for the first time. Resonant response properties are given by the formalism without phenomenological parameters. Example propagations with a developmental code are given demonstrating the treatment of electron-correlation in absorption spectra, vibronic structure, and decay in an open system.

  2. An Electronic Prosthesis Mimicking the Dynamic Vestibular Andrei M. Shkela

    E-Print Network [OSTI]

    Tang, William C

    An Electronic Prosthesis Mimicking the Dynamic Vestibular Function Andrei M. Shkela a prosthesis. The sensing element of the prosthesis is a custom designed one-axis MEMS gyroscope. Similarly the corresponding vestibular nerve branch. Our preliminary experimental evaluations of the prosthesis on a rate

  3. An Electronic Prosthesis Mimicking the Dynamic Vestibular Function

    E-Print Network [OSTI]

    Tang, William C

    An Electronic Prosthesis Mimicking the Dynamic Vestibular Function Jiayin Liu Mechanical of a novel MEMS-based electrostimulatory prosthesis cur- rently investigated by this research group [1 a prosthesis that matches the signal recorded from the vestibular nerve in squirrel monkey experiments reported

  4. Simulation of electron cooling dynamic ( December 16, 2003)

    E-Print Network [OSTI]

    approach in BetaCool code also leads to fast cooling of beam core ­ benchmarking in progress different and momentum are being benchmarked cooling #12;Progress · We have better understanding of friction forceSimulation of electron cooling dynamic ( December 16, 2003) A. Fedotov, I. Ben-zvi, Yu. Eidelman, V

  5. Trajectory-Wave Approach to Electron Dynamics in Hydrogen Atom

    E-Print Network [OSTI]

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

    2011-02-08T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1992-07-01T23:59:59.000Z

    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.

  7. Photocathode Optimization for a Dynamic Transmission Electron Microscope: Final Report

    SciTech Connect (OSTI)

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

    2011-08-04T23:59:59.000Z

    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.

  8. 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...

  9. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy ChinaofSchaeferApril 1, 1999 Inspection of SelectedIG-1CONFERENCE ofLandfill Gas to7AC

  10. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy ChinaofSchaeferApril 1, 1999 Inspection of SelectedIG-1CONFERENCE ofLandfill Gas

  11. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy ChinaofSchaeferApril 1, 1999 Inspection of SelectedIG-1CONFERENCE ofLandfill GasTrakLok

  12. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy ChinaofSchaeferApril 1, 1999 Inspection of SelectedIG-1CONFERENCE ofLandfill GasTrakLok333

  13. 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...

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

    E-Print Network [OSTI]

    Li, Haifei

    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

  15. Quantum Chemical Analysis of the Excited State Dynamics of Hydrated Electrons

    E-Print Network [OSTI]

    P. O. J. Scherer; Sighart F. Fischer

    2006-02-01T23:59:59.000Z

    Quantum calculations are performed for an anion water cluster representing the first hydration shell of the solvated electron in solution. The absorption spectra from the ground state, the instant excited states and the relaxed excited states are calculated including CI-SD interactions. Analytic expressions for the nonadiabatic relaxation are presented. It is shown that the 50fs dynamics recently observed after s->p excitation is best accounted for if it is identified with the internal conversion, preceded by an adiabatic relaxation within the excited p state. In addition, transient absorptions found in the infrared are qualitatively reproduced by these calculations .

  16. Pulsed Power for a Dynamic Transmission Electron Microscope

    SciTech Connect (OSTI)

    dehope, w j; browning, n; campbell, g; cook, e; king, w; lagrange, t; reed, b; stuart, b; Shuttlesworth, R; Pyke, B

    2009-06-25T23:59:59.000Z

    Lawrence Livermore National Laboratory (LLNL) has converted a commercial 200kV transmission electron microscope (TEM) into an ultrafast, nanoscale diagnostic tool for material science studies. The resulting Dynamic Transmission Electron Microscope (DTEM) has provided a unique tool for the study of material phase transitions, reaction front analyses, and other studies in the fields of chemistry, materials science, and biology. The TEM's thermionic electron emission source was replaced with a fast photocathode and a laser beam path was provided for ultraviolet surface illumination. The resulting photoelectron beam gives downstream images of 2 and 20 ns exposure times at 100 and 10 nm spatial resolution. A separate laser, used as a pump pulse, is used to heat, ignite, or shock samples while the photocathode electron pulses, carefully time-synchronized with the pump, function as probe in fast transient studies. The device functions in both imaging and diffraction modes. A laser upgrade is underway to make arbitrary cathode pulse trains of variable pulse width of 10-1000 ns. Along with a fast e-beam deflection scheme, a 'movie mode' capability will be added to this unique diagnostic tool. This talk will review conventional electron microscopy and its limitations, discuss the development and capabilities of DTEM, in particularly addressing the prime and pulsed power considerations in the design and fabrication of the DTEM, and conclude with the presentation of a deflector and solid-state pulser design for Movie-Mode DTEM.

  17. Linear and nonlinear dynamics of electron temperature gradient mode in non-Maxwellian plasmas

    SciTech Connect (OSTI)

    Zakir, U.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar (Pakistan)] [Institute of Physics and Electronics, University of Peshawar, Peshawar (Pakistan); Haque, Q. [Theoretical Plasma Physics Division, PINSTECH, Islamabad (Pakistan) [Theoretical Plasma Physics Division, PINSTECH, Islamabad (Pakistan); National Centre for Physics, Islamabad (Pakistan)

    2013-05-15T23:59:59.000Z

    The effect of non-Maxwellian distributed ions on electron temperature gradient mode is investigated. The linear dispersion relation of ?{sub e}?mode is obtained which shows that the behavior of this mode changes in the presence of superthermal ions. The growth rate of ?{sub e}?mode driven linear instability is found and is observed to modify due to nonthermal ions. However, it is found that this leaves the electron energy transport coefficient unchanged. In the nonlinear regime, a dipolar vortex solution is derived which indicates that the dynamic behavior of the vortices changes with the inclusion of kappa distributed ions. The importance of present study with respect to space and laboratory plasmas is also pointed out.

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

    SciTech Connect (OSTI)

    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

    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.

  19. Electron-spin dynamics in elliptically polarized light waves

    E-Print Network [OSTI]

    Heiko Bauke; Sven Ahrens; Rainer Grobe

    2014-11-03T23:59:59.000Z

    We investigate the coupling of the spin angular momentum of light beams with elliptical polarization to the spin degree of freedom of free electrons. It is shown that this coupling, which is of similar origin as the well-known spin-orbit coupling, can lead to spin precession. The spin-precession frequency is proportional to the product of the laser-field's intensity and its spin density. The electron-spin dynamics is analyzed by employing exact numerical methods as well as time-dependent perturbation theory based on the fully relativistic Dirac equation and on the nonrelativistic Pauli equation that is amended by a relativistic correction that accounts for the light's spin density.

  20. 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

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

    SciTech Connect (OSTI)

    Rantaharju, Jyrki, E-mail: jjrantaharju@gmail.com; Mareš, Ji?í, 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

    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.

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

    E-Print Network [OSTI]

    published as an Advance Article on the web 28th January 2004 Photo-excitation of chromophoric metal forward and back electron transfer reactions involving molecular dyes and wide bandgap semiconductors words, electro- nic coupling rather than nuclear motion appears to govern the reaction dynamics

  3. SOLUTIONS

    E-Print Network [OSTI]

    2012-07-04T23:59:59.000Z

    MA 162 - Quiz 5 (20 minutes). SOLUTIONS. The solutions I present are not necessarily the only solutions. As long as you give a correct method of solving a ...

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

    SciTech Connect (OSTI)

    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

    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.

  5. Dynamic studies of catalysts for biofuel synthesis in an Environmental Transmission Electron Microscope

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Dynamic studies of catalysts for biofuel synthesis in an Environmental Transmission Electron@cen.dtu.dk Keywords: Biofuel, catalysis, environmental TEM The development of transportation fuels from sustainable

  6. "Particle-like" singular solutions in Einstein-Maxwell theory and in algebraic dynamics

    E-Print Network [OSTI]

    V. V. Kassandrov; V. N. Trishin

    2000-07-13T23:59:59.000Z

    Foundations of algebrodynamics based on earlier proposed equations of biquaternionic holomorphy are briefly expounded. Free Maxwell and Yang-Mills Eqs. are satisfied identically on the solutions of primary system which is also related to the Eqs. of shear-free null congruences (SFC), and through them - to the Einstein-Maxwell electrovacuum system. Kerr theorem for SFC reduces the basic system to one algebraic equation, so that with each solution of the latter some (singular) solution of vacuum Eqs. may be associated. We present some exact solutions of basic algebraic and of related field Eqs. with compact structure of singularities of electromagnetic field, in particular having the form of figure "8" curve. Fundamental solution to primary system is analogous to the metric and fields of the Kerr-Newman solution. In addition, in the framework of algebraic dynamics the value of electric charge for this solution is strictly fixed in magnitude and may be set equal to the elementary charge.

  7. Model Proton-Coupled Electron Transfer Reactions in Solution: Predictions of Rates, Mechanisms, and Kinetic Isotope Effects

    E-Print Network [OSTI]

    Hammes-Schiffer, Sharon

    Model Proton-Coupled Electron Transfer Reactions in Solution: Predictions of Rates, Mechanisms isotope effects for proton-coupled electron transfer (PCET) reactions. These studies are based, the solvent is represented as a dielectric continuum, and the active electrons and transferring protons

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

    E-Print Network [OSTI]

    Peinke, Joachim

    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

  9. Dynamics of excess electrons in atomic and molecular clusters

    E-Print Network [OSTI]

    Young, Ryan Michael

    2011-01-01T23:59:59.000Z

    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)

  10. Dynamic structure factor of a stiff polymer in a glassy solution

    E-Print Network [OSTI]

    J. Glaser; O. Hallatschek; K. Kroy

    2008-05-29T23:59:59.000Z

    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.

  11. Method and means for dynamic measurement of rates of adsorption from solutions

    DOE Patents [OSTI]

    Slomka, B.J.; Buttermore, W.H.

    1992-05-05T23:59:59.000Z

    A method and apparatus are described for the dynamic measurement of rates of absorption from solutions. The method has the advantage of avoiding the use of solvent normally used to establish a baseline. The method involves pre-evacuating the adsorbent contained in an adsorbent cell and thereafter rapidly contacting the adsorbent with analytical solution, all without prior exposure of adsorbent to pure solvent. The result is a sharp characteristic adsorption line. 5 figs.

  12. Method and means for dynamic measurement of rates of adsorption from solutions

    DOE Patents [OSTI]

    Slomka, Bogdan J. (Ames, IA); Buttermore, William H. (Ames, IA)

    1992-05-05T23:59:59.000Z

    A method and apparatus for dynamic measurement of rates of absorption from solutions. The method has the advantage of avoiding the use of solvent normally used to establish a baseline. The method involves pre-evacuating the adsorbent contained in an adsorbent cell and thereafter rapidly contacting the adsorbent with analytical solution, all without prior exposure of adsorbent to pure solvent. The result is a sharp characteristic adsorption line.

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

    E-Print Network [OSTI]

    Krylov, Anna I.

    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

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

    E-Print Network [OSTI]

    KuÂ?el, Petr

    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

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

    E-Print Network [OSTI]

    Fayer, Michael D.

    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

  16. 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

  17. Dynamics of Hemoglobin in Human Erythrocytes and in Solution: Influence of Viscosity Studied by Ultrafast

    E-Print Network [OSTI]

    Fayer, Michael D.

    Dynamics of Hemoglobin in Human Erythrocytes and in Solution: Influence of Viscosity Studied by Ultrafast Vibrational Echo Experiments Brian L. McClain, Ilya J. Finkelstein, and M. D. Fayer* Contribution experiments are used to measure the vibrational dephasing of the CO stretching mode of hemoglobin-CO (Hb

  18. Ab initio electronic structure calculation of the redox potentials of bacteriochlorophyll and bacteriopheophytin in solution

    SciTech Connect (OSTI)

    Zhang, L.Y.; Friesner, R.A. [Columbia Univ., New York, NY (United States)

    1995-11-02T23:59:59.000Z

    We have carried out self-consistent reaction field (SCRF) calculations on the bacteriochlorophyll (BChl) and bacteriopheophytin (BPh) molecules at the Hartree-Fock level using the ab initio electronic structure code PSGVB together with an accurate numerical Poisson-Boltzmann solver. These are by far the largest ab initio SCRF computations carried out to date. We calculate redox potentials of these molecules in DMF solution for several geometries and compare the results with experiments of Fajer and co-workers. While the absolute redox energies are substantially in error, due to neglect of electron correlation, the relative redox energies agree qualitatively with the experimental findings. Treatment of solvation is crucial in predicting the proper ordering of the BChl and BPh redox energies. These results have implications for calculation of redox energies of the chromophores in the photosynthetic reaction center. 23 refs., 2 figs., 2 tabs.

  19. Excited electron dynamics in bulk ytterbium: Time-resolved two-photon photoemission and GW+T ab initio calculations

    E-Print Network [OSTI]

    Aeschlimann, Martin

    relaxation dynamics is played by the electronic structure of the system close to the Fermi level. For exampleExcited electron dynamics in bulk ytterbium: Time-resolved two-photon photoemission and GW+T ab November 2007 The excited electron dynamics in ytterbium is investigated by means of the time-resolved two

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

    E-Print Network [OSTI]

    Bruce Herold Dean

    2013-12-29T23:59:59.000Z

    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.

  1. Electron beam dynamics for the ISIS bremsstrahlung beam generation system

    E-Print Network [OSTI]

    Block, Robert E. (Robert Edward)

    2011-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    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

    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.

  3. Molecular dynamics study of salt–solution interface: Solubility and surface charge of salt in water

    SciTech Connect (OSTI)

    Kobayashi, Kazuya; Liang, Yunfeng, E-mail: y-liang@earth.kumst.kyoto-u.ac.jp, E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp; Matsuoka, Toshifumi, E-mail: y-liang@earth.kumst.kyoto-u.ac.jp, E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp [Environment and Resource System Engineering, Kyoto University, Kyoto 615-8540 (Japan)] [Environment and Resource System Engineering, Kyoto University, Kyoto 615-8540 (Japan); Sakka, Tetsuo [Department of Energy and Hydrocarbon Chemistry, Kyoto University, Kyoto 615-8510 (Japan)] [Department of Energy and Hydrocarbon Chemistry, Kyoto University, Kyoto 615-8510 (Japan)

    2014-04-14T23:59:59.000Z

    The NaCl salt–solution interface often serves as an example of an uncharged surface. However, recent laser-Doppler electrophoresis has shown some evidence that the NaCl crystal is positively charged in its saturated solution. Using molecular dynamics (MD) simulations, we have investigated the NaCl salt–solution interface system, and calculated the solubility of the salt using the direct method and free energy calculations, which are kinetic and thermodynamic approaches, respectively. The direct method calculation uses a salt–solution combined system. When the system is equilibrated, the concentration in the solution area is the solubility. In the free energy calculation, we separately calculate the chemical potential of NaCl in two systems, the solid and the solution, using thermodynamic integration with MD simulations. When the chemical potential of NaCl in the solution phase is equal to the chemical potential of the solid phase, the concentration of the solution system is the solubility. The advantage of using two different methods is that the computational methods can be mutually verified. We found that a relatively good estimate of the solubility of the system can be obtained through comparison of the two methods. Furthermore, we found using microsecond time-scale MD simulations that the positively charged NaCl surface was induced by a combination of a sodium-rich surface and the orientation of the interfacial water molecules.

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

    SciTech Connect (OSTI)

    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

    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.

  5. Coherent two-exciton dynamics measured using two-quantum rephasing two-dimensional electronic spectroscopy

    E-Print Network [OSTI]

    Turner, Daniel B.

    We use fifth-order two-dimensional electronic spectroscopy to measure coherent four-particle dynamics in a semiconductor nanostructure. By using optical polarization control in two-quantum measurements enabled by the COLBERT ...

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

    E-Print Network [OSTI]

    Ihee, Hyotcherl

    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 rearrangement [27]. In this work, we extend the time-slicing scheme to a protein, horse heart myoglobin (Mb

  7. Dynamic Nuclear Polarization with Single Electron Spins J. R. Petta,1,2

    E-Print Network [OSTI]

    Petta, Jason

    Dynamic Nuclear Polarization with Single Electron Spins J. R. Petta,1,2 J. M. Taylor,1,3 A. C Barbara, California 93106, USA (Received 6 September 2007; published 11 February 2008) We polarize nuclear'' an electron spin and ``flopping'' a nuclear spin. The resulting Overhauser field approaches 80 m

  8. 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

  9. Electronic processes in fast thermite chemical reactions: A first-principles molecular dynamics study

    E-Print Network [OSTI]

    Southern California, University of

    Electronic processes in fast thermite chemical reactions: A first-principles molecular dynamics composites. We have investigated the thermite reaction of Fe2O3 with aluminum by molecular dynamics as thermite reaction, is widely utilized in the synthesis and processing of materials 1 . In addition

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

    E-Print Network [OSTI]

    Boyer, Edmond

    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

  11. Dynamic Power Management of Electronic Circuits and Systems Luca Benini GiovanniDe Micheli

    E-Print Network [OSTI]

    De Micheli, Giovanni

    Dynamic Power Management of Electronic Circuits and Systems Luca Benini GiovanniDe Micheli Stanford University Stanford,CA 94305 Abstract- Dynamic power management is a design methodology aiming at controlling approaches to power manage- ment, and we discuss issues related to the design of computer-aided design tools

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Pan, Heng

    2009-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Pan, Heng

    2009-01-01T23:59:59.000Z

    Fig. 1. 1 Flexible electronics and flexible solar cells. Inof metal oxide based electronics on heat sensitive flexibleNanoparticles for Low-cost Electronics and Photovoltaics by

  15. General analytic solution of R sup 2 gravity with dynamical torsion in two dimensions

    SciTech Connect (OSTI)

    Kummer, W.; Schwarz, D.J. (Institut fuer Theoretische Physik, Technische Universitaet Wien, Wiedner Haupstrasse 8-10, A-1040 Wien (Austria))

    1992-05-15T23:59:59.000Z

    Using light-cone variables, we show that {ital R}{sup 2} gravity with dynamical torsion in two dimensions is one of the rare field theories whose {ital complete} classical solution in closed form can be obtained. It fulfils an invariant relation between the cosmological constant, the curvature scalar, and the scalar formed by the torsion tensor. We conjecture that this relation, interpreted as a local conservation law, is closely connected to the integrability of the theory. The solutions may possess a rich spectrum of singularities in curvature and torsion. Special cases, including one with nonvanishing torsion, can be used to elucidate some physical properties of the solution where by physical'' we imply the validity of concepts from general relativity such as measurements of distances and times and of extremal trajectories of a scalar test particle.

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

    SciTech Connect (OSTI)

    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

    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.

  17. Solution

    E-Print Network [OSTI]

    2011-09-09T23:59:59.000Z

    Solution: We're looking for the presale cost of the shirt, so let x be the price of ... The sale price is $10 and we've called the presale price x, so we need to solve.

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

    SciTech Connect (OSTI)

    Park, J.W.

    1988-01-01T23:59:59.000Z

    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.

  19. Ultrafast optical studies of electronic dynamics in semiconductors

    E-Print Network [OSTI]

    Ruzicka, Brian Andrew

    2012-05-31T23:59:59.000Z

    to their limited temporal resolution, electron measurement techniques cannot be used to study these processes on time scales in which the carrier-lattice system is not in equilibrium. However, in contemporary semiconductor devices with nanometer dimensions...

  20. Ultrafast control of strong-field electron dynamics in solids

    E-Print Network [OSTI]

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

    2015-02-17T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Chu, Shih-I

    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

  2. Probing reaction dynamics of transition-metal complexes in solution via time-resolved soft x-ray spectroscopy

    SciTech Connect (OSTI)

    Huse, N.; Kim, T.-K.; Khalil, M.; Jamula, L.; McCusker, J.K.; Schoenlein, R.W.

    2008-08-01T23:59:59.000Z

    We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding. We report the first time-resolved soft x-ray spectroscopy of solution-phase molecular dynamics. Changes in ligand-field splitting and spin-state populations in 3d orbitals of the Fe{sup II} complex are directly probed via transient absorption changes of the Fe L{sub 2} and L{sub 3} edges following photo-induced metal-to-ligand charge transfer. With the emergence of high-flux ultrafast soft x-ray sources, details on interplay between atomic structure, electronic states, and spin contributions will be revealed. Our experimental approach opens the door to femtosecond soft x-ray investigations of liquid phase chemistry that have previously been inaccessible.

  3. 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]

    Weston, Ken

    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

  4. Transient Dynamics in Molecular Junctions: Coherent Bichromophoric Molecular Electron Pumps

    E-Print Network [OSTI]

    Roie Volkovich; Uri Peskin

    2010-12-01T23:59:59.000Z

    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.

  5. Saturated Sodium Chloride Solution under an External Static Electric Field: a Molecular Dynamics Study

    E-Print Network [OSTI]

    Gan Ren; Yanting Wang

    2015-05-02T23:59:59.000Z

    The behavior of saturated aqueous sodium chloride solutions under a constant external electric field (E) was studied by molecular dynamics (MD) simulation. Our dynamic MD simulations have indicated that the irreversible nucleation process towards crystallization is accelerated by a moderate E, but retarded or even prohibited under a stronger E, which can be understood by the competition between self-diffusion and drift motion. The former increases with E resulting in the acceleration of the nucleation process, and the latter tears oppositely charged ions more apart under a stronger E leading to the deceleration of nucleation. Moreover, our steady-state MD simulations have indicated that a first-order phase transition happens in saturated solutions only when the applied E is below a certain threshold Ec, and the ratio of crystallized ions does not change with the electric field. The magnitude of Ec increases with concentration, because larger clusters are easy to form in a more concentrated solution and require a stronger E to dissociate them.

  6. The viscosity radius in dilute polymer solutions: Universal behaviour from DNA rheology and Brownian dynamics simulations

    E-Print Network [OSTI]

    Sharadwata Pan; D. Ahirwal; Duc At Nguyen; T. Sridhar; P. Sunthar; J. Ravi Prakash

    2014-10-14T23:59:59.000Z

    The swelling of the viscosity radius, $\\alpha_\\eta$, and the universal viscosity ratio, $U_{\\eta R}$, have been determined experimentally for linear DNA molecules in dilute solutions with excess salt, and numerically by Brownian dynamics simulations, as a function of the solvent quality. In the latter instance, asymptotic parameter free predictions have been obtained by extrapolating simulation data for finite chains to the long chain limit. Experiments and simulations show a universal crossover for $\\alpha_\\eta$ and $U_{\\eta R}$ from $\\theta$ to good solvents in line with earlier observations on synthetic polymer-solvent systems. The significant difference between the swelling of the dynamic viscosity radius from the observed swelling of the static radius of gyration, is shown to arise from the presence of hydrodynamic interactions in the non-draining limit. Simulated values of $\\alpha_\\eta$ and $U_{\\eta R}$ are in good agreement with experimental measurements in synthetic polymer solutions reported previously, and with the measurements in linear DNA solutions reported here.

  7. Attosecond intramolecular electron dynamics A. Becker1,a

    E-Print Network [OSTI]

    Becker, Andreas

    ), 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

  8. OPTIMAL CONTROL OF ATOMIC, MOLECULAR AND ELECTRON DYNAMICS

    E-Print Network [OSTI]

    Kassel, Universität

    , the dream was realized to actively exert control over quantum systems. Active control over the dynamics of quantum mechanical systems is a fascinating perspective in modern physics. Cleavage and creation? The theoretical and experimental development of suitable control schemes is a fascinating prospect of modern

  9. Exact and variational solutions of 3D Eigenmodes in high gain Free Electron Lasers

    E-Print Network [OSTI]

    Xie, M.

    2011-01-01T23:59:59.000Z

    Motz, Undulators and Free-Electron Lasers, (Clarendon Press,in High . Gain Free Electron Lasers MingXie Accelerator andin High Gain Free Electron Lasers Ming Xie Accelerator and

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

    E-Print Network [OSTI]

    Anirban Gangopadhyay; Maxim Dzero; Victor Galitski

    2010-05-05T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2005-10-06T23:59:59.000Z

    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.

  12. Small Polaron Hopping in LixFePO4 Solid Solutions: Coupled Lithium-Ion and Electron Mobility

    E-Print Network [OSTI]

    Ryan, Dominic

    Small Polaron Hopping in LixFePO4 Solid Solutions: Coupled Lithium-Ion and Electron Mobility Brian recognized as very promising electrodes for lithium-ion batteries because of their energy storage capacity as a cathode material in lithium-ion batteries almost a decade ago1 and has shown considerable promise due

  13. Influence of different focusing solutions for the TESLA X-ray FEL's on debunching of the electron beam

    E-Print Network [OSTI]

    Influence of different focusing solutions for the TESLA X-ray FEL's on debunching of the electron), Notkestr. 85, 22607 Hamburg, Germany Abstract For SASE-FELs the total undulator length increases different types of focusing for the TESLA X-ray FEL parameters will be discussed. 1. Introduction The TESLA

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

    E-Print Network [OSTI]

    Scherer, Norbert F.

    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

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

    SciTech Connect (OSTI)

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

    2007-06-22T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2012-09-06T23:59:59.000Z

    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.

  17. Large dynamic range diagnostics for high current electron LINACs

    SciTech Connect (OSTI)

    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

    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.

  18. Electronic Structure and Excited State Dynamics in Biological and Nanoscale

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State Hybridization in Heavy-FermionSystems | MIT-Harvard

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

    E-Print Network [OSTI]

    V. N. Zirakashvili; F. Aharonian

    2007-10-26T23:59:59.000Z

    %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.

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

    SciTech Connect (OSTI)

    Whitten, D.G.

    1992-12-01T23:59:59.000Z

    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.

  1. attosecond electron-hole dynamics: Topics by E-print Network

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

    attosecond electron-hole dynamics First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Entangled Valence...

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

    E-Print Network [OSTI]

    Bao, Xinhe

    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

  3. Modelling dynamics of samples exposed to free-electron-laser radiation with Boltzmann equations

    E-Print Network [OSTI]

    Beata Ziaja; Antonio R. B. de Castro; Edgar Weckert; Thomas Moeller

    2005-12-20T23:59:59.000Z

    We apply Boltzmann equations for modelling the radiation damage in samples irradiated by photons from free electron laser (FEL). We test this method in a study case of a spherically symmetric xenon cluster irradiated with VUV FEL photons. The results obtained demonstrate the potential of the Boltzmann method for describing the complex and non-equilibrium dynamics of samples exposed to FEL radiation.

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

    SciTech Connect (OSTI)

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

    2012-07-25T23:59:59.000Z

    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 (µs) 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 DOE’s 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.

  5. Electronic Structure and Lattice Dynamics of the Magnetic Shape Memory Alloy Co2NiGa

    SciTech Connect (OSTI)

    Siewert, M.; Shapiro, S.; Gruner, M.E.; Dannenberg, A.; Hucht, A.; Xu, G.; Schlagel, D.L.; Lograsso, T.A.; Entel1, P.

    2010-08-20T23:59:59.000Z

    In addition to the prototypical Ni-Mn-based Heusler alloys, the Co-Ni-Ga systems have recently been suggested as another prospective materials class for magnetic shape-memory applications. We provide a characterization of the dynamical properties of this material and their relation to the electronic structure within a combined experimental and theoretical approach. This relies on inelastic neutron scattering to obtain the phonon dispersion while first-principles calculations provide the link between dynamical properties and electronic structure. In contrast to Ni{sub 2}MnGa, where the softening of the TA{sub 2} phonon branch is related to Fermi-surface nesting, our results reveal that the respective anomalies are absent in Co-Ni-Ga, in the phonon dispersions as well as in the electronic structure.

  6. A quantum simulator for molecules: Imaging molecular orbitals and electronic dynamics with ultracold atoms

    E-Print Network [OSTI]

    Lühmann, Dirk-Sören; Sengstock, Klaus

    2015-01-01T23:59:59.000Z

    In the recent years, ultracold atoms in optical lattices have proven their great value as quantum simulators for studying strongly-correlated phases and complex phenomena in solid-state systems. Here we reveal their potential as quantum simulators for molecular physics and propose a technique to image the three-dimensional molecular orbitals with high resolution. The outstanding tunability of ultracold atoms in terms of potential and interaction offer fully-adjustable model systems for gaining deep insight into the electronic structure of molecules. We study the orbitals of an artificial benzene molecule and discuss the effect of tunable interactions in its conjugated pi electron system with special regard to localization and spin order. The dynamical timescale of ultracold atom simulators are on the order milliseconds which allow for the time-resolved monitoring of a broad range of dynamical processes. As an example, we compute the hole dynamics in the conjugated pi system of the artificial benzene molecule.

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    Morzan, Uriel N.; Ramírez, Francisco F.; Scherlis, Damián A., E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, Buenos Aires (C1428EHA) (Argentina); Oviedo, M. Belén; Sánchez, Cristián G. [Departamento de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba (Argentina)] [Departamento de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba (Argentina); Lebrero, Mariano C. González, E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Instituto de Química y Fisicoquímica Biológicas, IQUIFIB, CONICET (Argentina)] [Instituto de Química y Fisicoquímica Biológicas, IQUIFIB, CONICET (Argentina)

    2014-04-28T23:59:59.000Z

    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 matrix—required 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.

  9. Dynamic nuclear polarization with simultaneous excitation of electronic and nuclear transitions

    E-Print Network [OSTI]

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

    2008-05-28T23:59:59.000Z

    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.

  10. 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

  11. Dynamics of semi-flexible polymer solutions in the highly entangled regime

    E-Print Network [OSTI]

    Manlio Tassieri; R. M. L. Evans; Lucian Barbu-Tudoran; G. Nasir Khan; John Trinick; Tom A. Waigh

    2008-10-17T23:59:59.000Z

    We present experimental evidence that the effective medium approximation (EMA), developed by D.C. Morse [Phys. Rev. E {\\bf 63}, 031502, (2001)], provides the correct scaling law of the macroscopic plateau modulus $G^{0}\\propto\\rho^{4/3}L^{-1/3}_{p}$ (where $\\rho$ is the contour length per unit volume and $L_{p}$ is the persistence length) of semi-flexible polymer solutions, in the highly entangled concentration regime. Competing theories, including a self-consistent binary collision approximation (BCA), have instead predicted $G^{0}\\propto\\rho^{7/5}L^{-1/5}_{p}$. We have tested both the EMA and BCA scaling predictions using actin filament (F-actin) solutions which permit experimental control of $L_p$ independently of other parameters. A combination of passive video particle tracking microrheology and dynamic light scattering yields independent measurements of the elastic modulus $G$ and $L_{p}$ respectively. Thus we can distinguish between the two proposed laws, in contrast to previous experimental studies, which focus on the (less discriminating) concentration functionality of $G$.

  12. Dynamics of a delayed-feedback semiconductor laser depending on the number of stationary solutions

    SciTech Connect (OSTI)

    Napartovich, A P; Sukharev, Aleksandr G [State Research Center of Russian Federation 'Troitsk Institute for Innovation and Fusion Research', Troitsk, Moscow Region (Russian Federation)

    2004-07-31T23:59:59.000Z

    The lasing regimes of a diode laser with an external mirror are studied using the Lang - Kobayashi (LK) equations in the limit of a small distance from the mirror. The system of LK equations is integrated directly with the help of a program package developed. In addition, the instability and bifurcation points of solutions are found by calculating numerically the contour integral and the spectrum of Lyapunov exponents is calculated. The hysteresis zones of the lasing dynamics are found, which appear when the phase of a reflected signal changes. The parameters are determined at which two or three attractors corresponding to different dynamic regimes coexist in the phase space. It is shown that, when the rest of parameters are fixed, an increase in the pump power leads to a chaotic regime according to a classical scenario via period-doubling bifurcations. The regions of parameters are found in which packets of regular pulsations are generated, and the transition of these packets to the chaotic regime is observed. (lasers, active media)

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  15. Optimal Control of Quantum Dissipative Dynamics: Analytic solution for cooling the three level $?$ system

    E-Print Network [OSTI]

    Shlomo E. Sklarz; David J. Tannor; Navin Khaneja

    2004-02-19T23:59:59.000Z

    We study the problem of optimal control of dissipative quantum dynamics. Although under most circumstances dissipation leads to an increase in entropy (or a decrease in purity) of the system, there is an important class of problems for which dissipation with external control can decrease the entropy (or increase the purity) of the system. An important example is laser cooling. In such systems, there is an interplay of the Hamiltonian part of the dynamics, which is controllable and the dissipative part of the dynamics, which is uncontrollable. The strategy is to control the Hamiltonian portion of the evolution in such a way that the dissipation causes the purity of the system to increase rather than decrease. The goal of this paper is to find the strategy that leads to maximal purity at the final time. Under the assumption that Hamiltonian control is complete and arbitrarily fast, we provide a general framework by which to calculate optimal cooling strategies. These assumptions lead to a great simplification, in which the control problem can be reformulated in terms of the spectrum of eigenvalues of $\\rho$, rather than $\\rho$ itself. By combining this formulation with the Hamilton-Jacobi-Bellman theorem we are able to obtain an equation for the globaly optimal cooling strategy in terms of the spectrum of the density matrix. For the three-level $\\Lambda$ system, we provide a complete analytic solution for the optimal cooling strategy. For this system it is found that the optimal strategy does not exploit system coherences and is a 'greedy' strategy, in which the purity is increased maximally at each instant.

  16. Centrifugal separation and equilibration dynamics in an electron-antiproton plasma

    E-Print Network [OSTI]

    G. B. Andresen; M. D. Ashkezari; M. Baquero-Ruiz; W. Bertsche; P. D. Bowe; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; A. Deller; S. Eriksson; J. Fajans; T. Friesen; M. C. Fujiwara; D. R. Gill; A. Gutierrez; J. S. Hangst; W. N. Hardy; M. E. Hayden; A. J. Humphries; R. Hydomako; S. Jonsell; N. Madsen; S. Menary; P. Nolan; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; D. M. Silveira; C. So; J. W. Storey; R. I. Thompson; D. P. van der Werf; J. S. Wurtele; Y. Yamazaki

    2011-04-26T23:59:59.000Z

    Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally-separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally-separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.

  17. Electron beam dynamics in the DARHT-II linear induction accelerator

    SciTech Connect (OSTI)

    Ekdahl, Carl A [Los Alamos National Laboratory; Abeyta, Epifanio O [Los Alamos National Laboratory; Aragon, Paul [Los Alamos National Laboratory; Archuleta, Rita [Los Alamos National Laboratory; Cook, Gerald [Los Alamos National Laboratory; Dalmas, Dale [Los Alamos National Laboratory; Esquibel, Kevin [Los Alamos National Laboratory; Gallegos, Robert A [Los Alamos National Laboratory; Garnett, Robert [Los Alamos National Laboratory; Harrison, James F [Los Alamos National Laboratory; Johnson, Jeffrey B [Los Alamos National Laboratory; Jacquez, Edward B [Los Alamos National Laboratory; Mccuistian, Brian T [Los Alamos National Laboratory; Montoya, Nicholas A [Los Alamos National Laboratory; Nath, Subrata [Los Alamos National Laboratory; Nielsen, Kurt [Los Alamos National Laboratory; Oro, David [Los Alamos National Laboratory; Prichard, Benjamin [Los Alamos National Laboratory; Rowton, Lawrence [Los Alamos National Laboratory; Sanchez, Manolito [Los Alamos National Laboratory; Scarpetti, Raymond [Los Alamos National Laboratory; Schauer, Martin M [Los Alamos National Laboratory; Seitz, Gerald [Los Alamos National Laboratory; Schulze, Martin [Los Alamos National Laboratory; Bender, Howard A [Los Alamos National Laboratory; Broste, William B [Los Alamos National Laboratory; Carlson, Carl A [Los Alamos National Laboratory; Frayer, Daniel K [Los Alamos National Laboratory; Johnson, Douglas E [Los Alamos National Laboratory; Tom, C Y [Los Alamos National Laboratory; Trainham, C [NSTEC/STL; Williams, John [Los Alamos National Laboratory; Genoni, Thomas [VOSS; Hughes, Thomas [VOSS; Toma, Carsten [VOSS

    2008-01-01T23:59:59.000Z

    The DARHT-II linear induction accelerator (LIA) accelerates a 2-kA electron beam to more than 17 MeV. The beam pulse has a greater than 1.5-microsecond flattop region over which the electron kinetic energy is constant to within 1%. The beam dynamics are diagnosed with 21 beam-position monitors located throughout the injector, accelerator, and after the accelerator exit, where we also have beam imaging diagnostics. We discuss the tuning of the injector and accelerator, and present data for the resulting beam dynamics. We discuss the tuning procedures and other methods used to minimize beam motion, which is undesirable for its application as a bremsstrahlung source for multi-pulse radiography of exlosively driven hydrodynamic experiments. We also present beam stability measurements, which we relate to previous stability experiments at lower current and energy.

  18. First-principles calculations of the structural, dynamical, and electronic properties of liquid MgO Bijaya B. Karki,1 Dipesh Bhattarai,1 and Lars Stixrude2,

    E-Print Network [OSTI]

    Stixrude, Lars

    First-principles calculations of the structural, dynamical, and electronic properties of liquid Mg first-principles study,10 the structural, dynamic, and electronic properties of the liquid state are yet, dynamical, and electronic properties of liquid MgO have been investigated over a wide range of pressure 0

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Kowalczyk, Timothy Daniel

    2012-01-01T23:59:59.000Z

    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 ...

  1. Electronic readout of microchannel resonators for precision mass sensing in solution by Rumi Chunara.

    E-Print Network [OSTI]

    Chunara, Rumi

    2010-01-01T23:59:59.000Z

    Microfabricated transducers have enabled new approaches for detection of biomolecules and cells. Integration of electronics with these tools simplify systems and provide platforms for robust use outside of the laboratory ...

  2. Dynamics of cavitation bubble induced by 193 nm ArF excimer laser in concentrated sodium chloride solutions

    E-Print Network [OSTI]

    Palanker, Daniel

    of pulsed lasers for ablation, drilling, and cutting of soft tissues in liquid environments are accompaniedDynamics of cavitation bubble induced by 193 nm ArF excimer laser in concentrated sodium chloride solutions Igor Turovets and Daniel Palanker Laser Center, Hadassah University Hospital, P.O. Box 12000

  3. Surface residues dynamically organize water bridges to enhance electron transfer between proteins

    E-Print Network [OSTI]

    de la Lande, Aurélien; ?ezá?, Jan; Sanders, Barry C; Salahub, Dennis R; 10.1073/pnas.0914457107

    2010-01-01T23:59:59.000Z

    Cellular energy production depends on electron transfer (ET) between proteins. In this theoretical study, we investigate the impact of structural and conformational variations on the electronic coupling between the redox proteins methylamine dehydrogenase and amicyanin from Paracoccus denitrificans. We used molecular dynamics simulations to generate configurations over a duration of 40ns (sampled at 100fs intervals) in conjunction with an ET pathway analysis to estimate the ET coupling strength of each configuration. In the wild type complex, we find that the most frequently occurring molecular configurations afford superior electronic coupling due to the consistent presence of a water molecule hydrogen-bonded between the donor and acceptor sites. We attribute the persistence of this water bridge to a "molecular breakwater" composed of several hydrophobic residues surrounding the acceptor site. The breakwater supports the function of nearby solvent-organizing residues by limiting the exchange of water molecul...

  4. Dynamics of an electron in a relativistically intense laser field including radiaion reaction

    SciTech Connect (OSTI)

    Galkin, A. L., E-mail: galkin@kapella.gpi.ru [Prokhorov General Physics Institute of the Russian Academy of Science (Russian Federation)

    2012-08-15T23:59:59.000Z

    The dynamics of an electron in a relativistically intense laser pulse field is described with the radiation reaction being taken into account. The study is based on solving the Newton equation with the Lorentz and the radiation reaction forces. Validation is provided for an iteration technique which makes it possible to remove the discrepancies found in the theoretical models of radiation reaction. It is demonstrated that an electron having a high initial velocity and colliding head-on with a laser pulse sheds a considerable part of its kinetic energy due to the radiation reaction. A broadening of the electromagnetic pulse emitted by the electron occurs as a result of the same effect. The findings obtained can be used to experimentally verify the effect of radiation reaction.

  5. Electrons as probes of dynamics in molecules and clusters : a contribution from Time Dependent Density Functional Theory

    E-Print Network [OSTI]

    Wopperer, P; Reinhard, P -G; Suraud, E

    2014-01-01T23:59:59.000Z

    Various ways to analyze the dynamical response of clusters and molecules to electromagnetic perturbations exist. Particularly rich information can be obtained from measuring the properties of electrons emitted in the course of the excitation dynamics. Such an analysis of electron signals covers total ionization, Photo-Electron Spectra, Photoelectron Angular Distributions, and ideally combined PES/PAD, with a long history in molecular physics, also increasingly used in cluster physics. Recent progress in the design of new light sources (high intensity and/or frequency, ultra short pulses) opens new possibilities for measurements and thus has renewed the interest on the analysis of dynamical scenarios through these observables, well beyond a simple access to a density of states. This, in turn, has motivated many theoretical investigations of the dynamics of electronic emission for molecules and clusters. A theoretical tool of choice is here Time-Dependent Density Functional Theory (TDDFT) propagated in real tim...

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

    E-Print Network [OSTI]

    Igor Rychkov; Kenichi Yoshikawa

    2003-10-06T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  8. Analytical solution of electronic transport through a benzene molecule using lattice Green's functions

    E-Print Network [OSTI]

    E. J. C. Dias; N. M. R. Peres

    2015-02-25T23:59:59.000Z

    Using a Green's function formalism we derive analytical expressions for the electronic transmittance through a benzene ring. To motivate the approach we first solve the resonant level system and then extend the method to the benzene case. These results can be used to validate numerical methods.

  9. Dynamical mean-field theory using Wannier functions: A flexible route to electronic structure calculations of strongly correlated materials

    E-Print Network [OSTI]

    Boyer, Edmond

    Dynamical mean-field theory using Wannier functions: A flexible route to electronic structure materials with different degrees of structural and electronic complexity, SrVO3 and BaVS3, are investigated calculations of strongly correlated materials F. Lechermann,1,2, * A. Georges,1 A. Poteryaev,1 S. Biermann,1 M

  10. 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

  11. Nonadiabatic dynamics for processes involving multiple avoided curve crossings: Double proton transfer and proton-coupled electron transfer

    E-Print Network [OSTI]

    Hammes-Schiffer, Sharon

    Nonadiabatic dynamics for processes involving multiple avoided curve crossings: Double proton transfer and proton-coupled electron transfer reactions Jian-Yun Fang and Sharon Hammes June 1997; accepted 26 August 1997 The extension of the surface hopping method ``molecular dynamics

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

    E-Print Network [OSTI]

    Drabold, David

    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

  13. Nickel recovery from electronic waste II Electrodeposition of Ni and Ni–Fe alloys from diluted sulfate solutions

    SciTech Connect (OSTI)

    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 Universität 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 Universität 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

    Highlights: • Ni can be recovered from EG wastes as pure Ni or as Ni–Fe 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 Ni–Fe. - Abstract: This study focuses on the electrodeposition of Ni and Ni–Fe 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 Ni–Fe alloys can be tailored towards specific applications. Complementarily, the differences in the nucleation mechanisms for Ni, Fe and Ni–Fe 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 Ni–Fe, the obtained data points are best fitted to an instantaneous nucleation model.

  14. ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE

    SciTech Connect (OSTI)

    Zaheer, S. [Permanent address: Department of Physics, Forman Christian College, Lahore, Punjab 54000, Pakistan. (Pakistan); Yoon, P. H. [Also at SSR, KHU, Yongin, Korea. (Korea, Republic of)

    2013-10-01T23:59:59.000Z

    A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the ? distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized ? distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvénic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index ?, where f{sub e} ? v {sup –?} is close to the average index observed during the quiet-time solar wind condition, i.e., ? ? O(6.5) whereas ?{sub average} ? 6.69, according to observation.

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  19. Dynamics of the Aharonov-Bohm effect

    E-Print Network [OSTI]

    Neven Simicevic

    2010-03-24T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Nelson, W.R.; Namito, Yoshihito.

    1990-02-09T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Faghaninia, Alireza; Lo, Cynthia S

    2015-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

    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

    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.

  3. Determination of redox reaction rates and –orders by in-situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect (OSTI)

    Sutter, Eli A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sutter, Peter W. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-12-03T23:59:59.000Z

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  4. Determination of redox reaction rates and –orders by in-situ liquid cell electron microscopy of Pd and Au solution growth

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

    Sutter, Eli A.; Sutter, Peter W.

    2014-12-03T23:59:59.000Z

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pdmore »deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.« less

  5. Determination of redox reaction rates and –orders by in-situ liquid cell electron microscopy of Pd and Au solution growth

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

    Sutter, Eli A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sutter, Peter W. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-12-03T23:59:59.000Z

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  6. 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)

    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

    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.

  7. A water-processable organic electron-selective layer for solution-processed inverted organic solar cells

    SciTech Connect (OSTI)

    Chen, Dongcheng; Zhou, Hu; Cai, Ping; Sun, Shi; Ye, Hua; Su, Shi-Jian, E-mail: mssjsu@scut.edu.cn; Cao, Yong [State Key Laboratory of Luminescent Materials and Devices (South China University of Technology) and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640 (China)

    2014-02-03T23:59:59.000Z

    A triazine- and pyridinium-containing water-soluble material of 1,1?,1?-(4,4?,4?-(1,3,5-triazine-2,4,6-triyl)tris(benzene-4,1-diyl)) tris(methylene)tripyridinium bromide (TzPyBr) was developed as an organic electron-selective layer in solution-processed inverted organic solar cells due to its strong anti-erosion capacity against non-polar organic solvents commonly used for the active layer. Ohmic-like contact with the adjacent active materials like fullerene derivatives is speculated to be formed, as confirmed by the work-function measurements with scanning Kelvin probe and ultraviolet photoelectron spectroscopy techniques. Besides, considering the deep highest occupied molecular orbital energy level of TzPyBr, excellent hole-blocking property of the electron-selective layer is also anticipated. The inverted organic photovoltaic devices based on the TzPyBr/ITO (indium tin oxide) bilayer cathode exhibit dramatically enhanced performance compared to the control devices with bare ITO as the cathode and even higher efficiency than the conventional type devices with ITO and Al as the electrodes.

  8. International Congeress on Plasma Physics, Nice, France, 25-29 October 2004 Chaotic particle dynamics in free-electron lasers with coaxial wiggler

    E-Print Network [OSTI]

    Boyer, Edmond

    dynamics in free-electron lasers with coaxial wiggler B. Farokhi and S. Mobarakabadi Islamic Azad University of Arak, Arak, Iran The motion of a relativistic test electron in a free-electron laser orbits. Earlier investigations of chaos in free ­ electron lasers have focused on chaotic behavior

  9. Ultrafast myoglobin structural dynamics observed with an X-ray free-electron laser

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

    Levantino, Matteo; Schirò, Giorgio; Lemke, Henrik Till; Cottone, Grazia; Glownia, James Michael; Zhu, Diling; Chollet, Mathieu; Ihee, Hyotcherl; Cupane, Antonio; Cammarata, Marco

    2015-04-02T23:59:59.000Z

    Light absorption can trigger biologically relevant protein conformational changes. The light induced structural rearrangement at the level of a photoexcited chromophore is known to occur in the femtosecond timescale and is expected to propagate through the protein as a quake-like intramolecular motion. Here we report direct experimental evidence of such ‘proteinquake’ observed in myoglobin through femtosecond X-ray solution scattering measurements performed at the Linac Coherent Light Source X-ray free-electron laser. An ultrafast increase of myoglobin radius of gyration occurs within 1 picosecond and is followed by a delayed protein expansion. As the system approaches equilibrium it undergoes damped oscillations withmore »a ~3.6-picosecond time period. Our results unambiguously show how initially localized chemical changes can propagate at the level of the global protein conformation in the picosecond timescale.« less

  10. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

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

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; et al

    2015-03-04T23:59:59.000Z

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobicmore »environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.« less

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Alfè, Dario

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

  13. Coupled electron-nuclear dynamics: Charge migration and charge transfer initiated near a conical intersection

    SciTech Connect (OSTI)

    Mendive-Tapia, David; Vacher, Morgane; Bearpark, Michael J.; Robb, Michael A. [Department of Chemistry, Imperial College London, London SW7 2AZ (United Kingdom)] [Department of Chemistry, Imperial College London, London SW7 2AZ (United Kingdom)

    2013-07-28T23:59:59.000Z

    Coupled electron-nuclear dynamics, implemented using the Ehrenfest method, has been used to study charge migration with fixed nuclei, together with charge transfer when nuclei are allowed to move. Simulations were initiated at reference geometries of neutral benzene and 2-phenylethylamine (PEA), and at geometries close to potential energy surface crossings in the cations. Cationic eigenstates, and the so-called sudden approximation, involving removal of an electron from a correlated ground-state wavefunction for the neutral species, were used as initial conditions. Charge migration without coupled nuclear motion could be observed if the Ehrenfest simulation, using the sudden approximation, was started near a conical intersection where the states were both strongly coupled and quasi-degenerate. Further, the main features associated with charge migration were still recognizable when the nuclear motion was allowed to couple. In the benzene radical cation, starting from the reference neutral geometry with the sudden approximation, one could observe sub-femtosecond charge migration with a small amplitude, which results from weak interaction with higher electronic states. However, we were able to engineer large amplitude charge migration, with a period between 10 and 100 fs, corresponding to oscillation of the electronic structure between the quinoid and anti-quinoid cationic electronic configurations, by distorting the geometry along the derivative coupling vector from the D{sub 6h} Jahn-Teller crossing to lower symmetry where the states are not degenerate. When the nuclear motion becomes coupled, the period changes only slightly. In PEA, in an Ehrenfest trajectory starting from the D{sub 2} eigenstate and reference geometry, a partial charge transfer occurs after about 12 fs near the first crossing between D{sub 1}, D{sub 2} (N{sup +}-Phenyl, N-Phenyl{sup +}). If the Ehrenfest propagation is started near this point, using the sudden approximation without coupled nuclear motion, one observes an oscillation of the spin density – charge migration – between the N atom and the phenyl ring with a period of 4 fs. When the nuclear motion becomes coupled, this oscillation persists in a damped form, followed by an effective charge transfer after 30 fs.

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

    E-Print Network [OSTI]

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

    2014-01-27T23:59:59.000Z

    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.

  15. Statistical analysis of the dynamics of secondary electrons in the flare of a high-voltage beam-type discharge

    SciTech Connect (OSTI)

    Demkin, V. P.; Mel'nichuk, S. V. [National Research Tomsk State University, 36, Lenin Ave., 634050 Tomsk (Russian Federation)

    2014-09-15T23:59:59.000Z

    In the present work, results of investigations into the dynamics of secondary electrons with helium atoms in the presence of the reverse electric field arising in the flare of a high-voltage pulsed beam-type discharge and leading to degradation of the primary electron beam are presented. The electric field in the discharge of this type at moderate pressures can reach several hundred V/cm and leads to considerable changes in the kinetics of secondary electrons created in the process of propagation of the electron beam generated in the accelerating gap with a grid anode. Moving in the accelerating electric field toward the anode, secondary electrons create the so-called compensating current to the anode. The character of electron motion and the compensating current itself are determined by the ratio of the field strength to the concentration of atoms (E/n). The energy and angular spectra of secondary electrons are calculated by the Monte Carlo method for different ratios E/n of the electric field strength to the helium atom concentration. The motion of secondary electrons with threshold energy is studied for inelastic collisions of helium atoms and differential analysis is carried out of the collisional processes causing energy losses of electrons in helium for different E/n values. The mechanism of creation and accumulation of slow electrons as a result of inelastic collisions of secondary electrons with helium atoms and selective population of metastable states of helium atoms is considered. It is demonstrated that in a wide range of E/n values the motion of secondary electrons in the beam-type discharge flare has the character of drift. At E/n values characteristic for the discharge of the given type, the drift velocity of these electrons is calculated and compared with the available experimental data.

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

    E-Print Network [OSTI]

    Hassell, Joel Andre

    1968-01-01T23:59:59.000Z

    . . then the previous solution is the local optimum. This ij ? ij procedure is continued until a local optisnun is attained. To deter- mine if the local optimum is the optimal solution, compute m-1 min PI B'k. - R. j I ~ Kch [t+ I] Now, i f some S. . for the local... OF CON'1'ENTS PAGE. INTRODUCTION THE STORAGF. CONSTRAIiNT Tilr BASIC PROP 1, ENI AssuiaP1ions and Defi ni trans Tn~ OI jective Finiction Ut' x satIon Rates arid Rat! o Detenmiir5ng Optiinality SOiRi SOLVED PROBLEM'. S DiSCUSSION BIBLIOGPM11Y...

  17. 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 energy of the electron in the electrode). The observed insensitivity to large changes in band-functionalized ruthenium bipyridyl complexes to- gether with high-area nanocrystalline titanium dioxide films.2

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

    E-Print Network [OSTI]

    Umstadter, Donald

    . 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

  19. Vibrational Spectra of Water Solutions of Azoles from QM/MM Calculations: Effects of Solvation

    E-Print Network [OSTI]

    Guidoni, Leonardo

    the decomposition of the vibrational density of states of the gas phase and solution dynamics. The calculated shifts the structural and dynamical aspects of water solutions. X-ray as well as neutron diffraction are the main source and electronic structure of the molecule.1 We expect therefore that also its vibrational properties could

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

    SciTech Connect (OSTI)

    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 Fédérale 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

    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.

  1. An infrared free-electron laser for the Chemical Dynamics Research Laboratory

    SciTech Connect (OSTI)

    Vaughan, D. (comp.)

    1992-04-01T23:59:59.000Z

    This document describes a free-electron laser (FEL) proposed as part of the Chemical Dynamics Research Laboratory (CDRL), a user facility that also incorporates several advanced lasers of conventional design and two beamlines for the ALS. The FEL itself addresses the needs of the chemical sciences community for a high-brightness, tunable source covering a broad region of the infrared spectrum -- from 3 to 50 {mu}m. All of these sources, together with a variety of sophisticated experimental stations, will be housed in a new building to be located adjacent to the ALS. The radiation sources can be synchronized to permit powerful two-color, pump-probe experiments that will further our fundamental understanding of chemical dynamics at the molecular level, especially those aspects relevant to practical issues in combustion chemistry. The technical approach adopted in this design makes use of superconducting radiofrequency (SCRF) accelerating structures. The primary motivation for adopting this approach was to meet the user requirement for wavelength stability equal to one part in 10{sup 4}. Previous studies concluded that a wavelength stability of only one part in 10{sup 3} could be achieved with currently available room-temperature technology. In addition, the superconducting design operates in a continuous-wave (cw) mode and hence offers considerably higher average optical output power. It also allows for various pulse-gating configurations that will permit simultaneous multiuser operations. A summary of the comparative performance attainable with room-temperature and superconducting designs is given. The FEL described in this report provides a continuous train of 30-ps micropulses, with 100{mu}J of optical energy per micropulse, at a repetition rate of 6.1 MHz. The device can also deliver pulses at a cw repetition rate of 12.2 MHz, with a peak power of 50 {mu}J per micropulse. 70 ref.

  2. An infrared free-electron laser for the Chemical Dynamics Research Laboratory. Design report

    SciTech Connect (OSTI)

    Vaughan, D. [comp.

    1992-04-01T23:59:59.000Z

    This document describes a free-electron laser (FEL) proposed as part of the Chemical Dynamics Research Laboratory (CDRL), a user facility that also incorporates several advanced lasers of conventional design and two beamlines for the ALS. The FEL itself addresses the needs of the chemical sciences community for a high-brightness, tunable source covering a broad region of the infrared spectrum -- from 3 to 50 {mu}m. All of these sources, together with a variety of sophisticated experimental stations, will be housed in a new building to be located adjacent to the ALS. The radiation sources can be synchronized to permit powerful two-color, pump-probe experiments that will further our fundamental understanding of chemical dynamics at the molecular level, especially those aspects relevant to practical issues in combustion chemistry. The technical approach adopted in this design makes use of superconducting radiofrequency (SCRF) accelerating structures. The primary motivation for adopting this approach was to meet the user requirement for wavelength stability equal to one part in 10{sup 4}. Previous studies concluded that a wavelength stability of only one part in 10{sup 3} could be achieved with currently available room-temperature technology. In addition, the superconducting design operates in a continuous-wave (cw) mode and hence offers considerably higher average optical output power. It also allows for various pulse-gating configurations that will permit simultaneous multiuser operations. A summary of the comparative performance attainable with room-temperature and superconducting designs is given. The FEL described in this report provides a continuous train of 30-ps micropulses, with 100{mu}J of optical energy per micropulse, at a repetition rate of 6.1 MHz. The device can also deliver pulses at a cw repetition rate of 12.2 MHz, with a peak power of 50 {mu}J per micropulse. 70 ref.

  3. Postplasma particle dynamics in a Gaseous Electronics Conference RF Reference Cell

    SciTech Connect (OSTI)

    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

    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}

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Kervalishvili, N A

    2015-01-01T23:59:59.000Z

    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.

  6. Efficient "on-the-fly" calculation of Raman spectra from \\textit{ab-initio} molecular dynamics: Application to hydrophobic/hydrophilic solutes in bulk water

    E-Print Network [OSTI]

    Partovi-Azar, Pouya

    2015-01-01T23:59:59.000Z

    We present a computational method to accurately calculate Raman spectra from first principles with an at least one order of magnitude higher efficiency. This scheme thus allows to routinely calculate finite-temperature Raman spectra "on-the-fly" by means of \\textit{ab-initio} molecular dynamics simulations. To demonstrate the predictive power of this approach we investigate the effect of hydrophobic and hydrophilic solutes in water solution on the infrared and Raman spectra.

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

    SciTech Connect (OSTI)

    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

    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)

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Baluka, M.

    2013-01-01T23:59:59.000Z

    III) TO (VI) IN ANHYDROUS HYDROGEN FLUORIDE M. Baluka, N.III) TO (VI) IN ANHYDROUS HYDROGEN FLUORIDE M. Baluka(t), N.solutions in anhydrous hydrogen fluoride (AHF) of uranium

  10. Femtosecond Xray Absorption Spectroscopy at a Hard Xray Free Electron Laser: Application to Spin Crossover Dynamics

    E-Print Network [OSTI]

    Ihee, Hyotcherl

    Femtosecond Xray Absorption Spectroscopy at a Hard Xray Free Electron Laser: Application to Spin Rennes 1, F35042, Rennes, France ABSTRACT: X-ray free electron lasers (XFELs) deliver short ( operated in femtosecond laser slicing mode15 ). The development of new X-ray facilities such as X-ray free

  11. Ultrafast dynamics of hot electrons and holes in copper: Excitation, energy relaxation, and transport effects

    E-Print Network [OSTI]

    Wolf, Martin

    , and transport effects E. Knoesel, A. Hotzel, and M. Wolf Fritz-Haber-Institut der MPG, Faradayweg 4-6, D-14195 calculation, a simulation of the ballistic transport effect and its implication on the observed electron process for a hot electron is scattering with a ``cold'' elec- tron below the Fermi level, because

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

    E-Print Network [OSTI]

    McCusker, James K.

    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

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

    SciTech Connect (OSTI)

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

    2013-11-27T23:59:59.000Z

    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.

  14. 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...

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

    SciTech Connect (OSTI)

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

    1980-10-01T23:59:59.000Z

    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.

  16. Improving approximate-optimized effective potentials by imposing exact conditions: Theory and applications to electronic statics and dynamics

    SciTech Connect (OSTI)

    Kurzweil, Yair; Head-Gordon, Martin [Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 (United States) and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2009-07-15T23:59:59.000Z

    We develop a method that can constrain any local exchange-correlation potential to preserve basic exact conditions. Using the method of Lagrange multipliers, we calculate for each set of given Kohn-Sham orbitals a constraint-preserving potential which is closest to the given exchange-correlation potential. The method is applicable to both the time-dependent (TD) and independent cases. The exact conditions that are enforced for the time-independent case are Galilean covariance, zero net force and torque, and Levy-Perdew virial theorem. For the time-dependent case we enforce translational covariance, zero net force, Levy-Perdew virial theorem, and energy balance. We test our method on the exchange (only) Krieger-Li-Iafrate (xKLI) approximate-optimized effective potential for both cases. For the time-independent case, we calculated the ground state properties of some hydrogen chains and small sodium clusters for some constrained xKLI potentials and Hartree-Fock (HF) exchange. The results (total energy, Kohn-Sham eigenvalues, polarizability, and hyperpolarizability) indicate that enforcing the exact conditions is not important for these cases. On the other hand, in the time-dependent case, constraining both energy balance and zero net force yields improved results relative to TDHF calculations. We explored the electron dynamics in small sodium clusters driven by cw laser pulses. For each laser pulse we compared calculations from TD constrained xKLI, TD partially constrained xKLI, and TDHF. We found that electron dynamics such as electron ionization and moment of inertia dynamics for the constrained xKLI are most similar to the TDHF results. Also, energy conservation is better by at least one order of magnitude with respect to the unconstrained xKLI. We also discuss the problems that arise in satisfying constraints in the TD case with a non-cw driving force.

  17. Adjustment of ablation shapes and subwavelength ripples based on electron dynamics control by designing femtosecond laser pulse trains

    SciTech Connect (OSTI)

    Yuan Yanping; Jiang Lan; Li Xin; Wang Cong [Laser Micro/Nano-Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081 (China); Lu Yongfeng [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)

    2012-11-15T23:59:59.000Z

    A quantum model is proposed to investigate femtosecond laser pulse trains processing of dielectrics by including the plasma model with the consideration of laser particle-wave duality. Central wavelengths (400 nm and 800 nm) strongly impact the surface plasmon field distribution, the coupling field intensity distribution (between the absorbed intensity and the surface plasma), and the distribution of transient localized free electron density in the material. This, in turn, significantly changes the localized transient optical/thermal properties during laser materials processing. The effects of central wavelengths on ablation shapes and subwavelength ripples are discussed. The simulation results show that: (1) ablation shapes and the spacing of subwavelength ripples can be adjusted by localized transient electron dynamics control using femtosecond laser pulse trains; (2) the adjustment of the radii of ablation shapes is stronger than that of the periods of subwavelength ripples.

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

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    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 ...

  19. Electron beam dynamics in the long-pulse, high-current DARHT-II linear induction accelerator

    SciTech Connect (OSTI)

    Ekdahl, Carl A [Los Alamos National Laboratory; Abeyta, Epifanio O [Los Alamos National Laboratory; Aragon, Paul [Los Alamos National Laboratory; Archuleta, Rita [Los Alamos National Laboratory; Cook, Gerald [Los Alamos National Laboratory; Dalmas, Dale [Los Alamos National Laboratory; Esquibel, Kevin [Los Alamos National Laboratory; Gallegos, Robert A [Los Alamos National Laboratory; Garnett, Robert [Los Alamos National Laboratory; Harrison, James F [Los Alamos National Laboratory; Johnson, Jeffrey B [Los Alamos National Laboratory; Jacquez, Edward B [Los Alamos National Laboratory; Mccuistian, Brian T [Los Alamos National Laboratory; Montoya, Nicholas A [Los Alamos National Laboratory; Nath, Subrato [Los Alamos National Laboratory; Nielsen, Kurt [Los Alamos National Laboratory; Oro, David [Los Alamos National Laboratory; Prichard, Benjamin [Los Alamos National Laboratory; Rowton, Lawrence [Los Alamos National Laboratory; Sanchez, Manolito [Los Alamos National Laboratory; Scarpetti, Raymond [Los Alamos National Laboratory; Schauer, Martin M [Los Alamos National Laboratory; Seitz, Gerald [Los Alamos National Laboratory; Schulze, Martin [Los Alamos National Laboratory; Bender, Howard A [Los Alamos National Laboratory; Broste, William B [Los Alamos National Laboratory; Carlson, Carl A [Los Alamos National Laboratory; Frayer, Daniel K [Los Alamos National Laboratory; Johnson, Douglas E [Los Alamos National Laboratory; Tom, C Y [Los Alamos National Laboratory; Williams, John [Los Alamos National Laboratory; Hughes, Thomas [Los Alamos National Laboratory; Anaya, Richard [LLNL; Caporaso, George [LLNL; Chambers, Frank [LLNL; Chen, Yu - Jiuan [LLNL; Falabella, Steve [LLNL; Guethlein, Gary [LLNL; Raymond, Brett [LLNL; Richardson, Roger [LLNL; Trainham, C [NSTEC/STL; Watson, Jim [LLNL; Weir, John [LLNL; Genoni, Thomas [VOSS; Toma, Carsten [VOSS

    2009-01-01T23:59:59.000Z

    The DARHT-II linear induction accelerator (LIA) now accelerates 2-kA electron beams to more than 17 MeV. This LIA is unique in that the accelerated current pulse width is greater than 2 microseconds. This pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 microseconds. The long risetime of the 6-cell injector current pulse is 0.5 {micro}s, which can be scraped off in a beam-head cleanup zone before entering the 68-cell main accelerator. We discuss our experience with tuning this novel accelerator; and present data for the resulting beam transport and dynamics. We also present beam stability data, and relate these to previous stability experiments at lower current and energy.

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

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

    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).

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

    SciTech Connect (OSTI)

    Buß, J. H.; Schaefer, A.; Hägele, D.; Rudolph, J. [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstraße 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

    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.

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

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

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

    2015-03-01T23:59:59.000Z

    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.

  3. Electron dynamics of the buffer layer and bilayer graphene on SiC

    SciTech Connect (OSTI)

    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

    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.

  4. Dynamics of coupled electron-nucleon motion in a laser field

    SciTech Connect (OSTI)

    Hartmann, F.X.; Garcia, K.K.; Munro, J.K. Jr.; Noid, D.W.

    1987-01-01T23:59:59.000Z

    Energy transfer processes in single particle coupled nucleon-electron models interacting with an intense laser field are studied using semi-classical quantization of the coupled classical Hamiltonian. 11 refs., 2 figs.

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

    E-Print Network [OSTI]

    Sit, Patrick Hoi Land

    2006-01-01T23:59:59.000Z

    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 ...

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

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

    Zhang, Zhen; Tsinghua University, Beijing; Ding, Yuantao; Marinelli, Agostino; Huang, Zhirong

    2015-03-01T23:59:59.000Z

    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-bunchmore »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.« less

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

    SciTech Connect (OSTI)

    Arikan, Nihat [Ahi Evran Üniversitesi E?itim Fakültesi, ?lkö?retim Bölümü, K?r?ehir (Turkey); Özduran, Mustafa [Ahi Evran Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, K?r?ehir (Turkey)

    2014-10-06T23:59:59.000Z

    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 Perdew–Burke–Ernzerhof (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.

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

    SciTech Connect (OSTI)

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

    2007-06-14T23:59:59.000Z

    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.

  9. Ab initio molecular dynamics simulations reveal localization and time evolution dynamics of an excess electron in heterogeneous CO{sub 2}–H{sub 2}O systems

    SciTech Connect (OSTI)

    Liu, Ping; Zhao, Jing; Liu, Jinxiang; Zhang, Meng; Bu, Yuxiang, E-mail: byx@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)] [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)

    2014-01-28T23:59:59.000Z

    In view of the important implications of excess electrons (EEs) interacting with CO{sub 2}–H{sub 2}O clusters in many fields, using ab initio molecular dynamics simulation technique, we reveal the structures and dynamics of an EE associated with its localization and subsequent time evolution in heterogeneous CO{sub 2}–H{sub 2}O mixed media. Our results indicate that although hydration can increase the electron-binding ability of a CO{sub 2} molecule, it only plays an assisting role. Instead, it is the bending vibrations that play the major role in localizing the EE. Due to enhanced attraction of CO{sub 2}, an EE can stably reside in the empty, low-lying ?{sup *} orbital of a CO{sub 2} molecule via a localization process arising from its initial binding state. The localization is completed within a few tens of femtoseconds. After EE trapping, the ?OCO angle of the core CO{sub 2}{sup ?} oscillates in the range of 127°?142°, with an oscillation period of about 48 fs. The corresponding vertical detachment energy of the EE is about 4.0 eV, which indicates extreme stability of such a CO{sub 2}-bound solvated EE in [CO{sub 2}(H{sub 2}O){sub n}]{sup ?} systems. Interestingly, hydration occurs not only on the O atoms of the core CO{sub 2}{sup ?} through formation of O?H–O H–bond(s), but also on the C atom, through formation of a C?H–O H–bond. In the latter binding mode, the EE cloud exhibits considerable penetration to the solvent water molecules, and its IR characteristic peak is relatively red-shifted compared with the former. Hydration on the C site can increase the EE distribution at the C atom and thus reduce the C?H distance in the C?H–O H–bonds, and vice versa. The number of water molecules associated with the CO{sub 2}{sup ?} anion in the first hydration shell is about 4?7. No dimer-core (C{sub 2}O{sub 4}{sup ?}) and core-switching were observed in the double CO{sub 2} aqueous media. This work provides molecular dynamics insights into the localization and time evolution dynamics of an EE in heterogeneous CO{sub 2}–H{sub 2}O media.

  10. Dynamic Imaging of Au-nanoparticles via Scanning Electron Microscopy in a Graphene Wet Cell

    E-Print Network [OSTI]

    Wayne Yang; Yuning Zhang; Michael Hilke; Walter Reisner

    2015-06-10T23:59:59.000Z

    High resolution nanoscale imaging in liquid environments is crucial for studying molecular interactions in biological and chemical systems. In particular, electron microscopy is the gold-standard tool for nanoscale imaging, but its high-vacuum requirements make application to in-liquid samples extremely challenging. Here we present a new graphene based wet cell device where high resolution SEM (scanning electron microscope) and Energy Dispersive X-rays (EDX) analysis can be performed directly inside a liquid environment. Graphene is an ideal membrane material as its high transparancy, conductivity and mechanical strength can support the high vacuum and grounding requirements of a SEM while enabling maximal resolution and signal. In particular, we obtain high resolution (graphene wet cell and EDX analysis of nanoparticle composition in the liquid enviornment. Our obtained resolution surpasses current conventional silicon nitride devices imaged in both SEM and TEM under much higher electron doses.

  11. 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]

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

    2014-08-12T23:59:59.000Z

    , and engineering applications; examples include protein folding, membrane self-assembly, electron transfer reactions, heterogeneous catalysis, and fuel cell technology.1?4 Despite this, however, the influence of the solute molecules upon the structure of water... -Domain Spectroscopy. The THz-TDS transmission setup used in this study has been described previously.32 The liquid samples were contained within a liquid cell (PIKE Technologies, Madison U.S.A.) contained between 3 mm thick z-cut quartz windows, which are transparent...

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

    SciTech Connect (OSTI)

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

    2014-03-01T23:59:59.000Z

    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.

  13. Direct observation of ultrafast many-body electron dynamics in a strongly-correlated ultracold Rydberg gas

    E-Print Network [OSTI]

    Nobuyuki Takei; Christian Sommer; Claudiu Genes; Guido Pupillo; Haruka Goto; Kuniaki Koyasu; Hisashi Chiba; Matthias Weidemüller; Kenji Ohmori

    2015-04-14T23:59:59.000Z

    Many-body interactions govern a variety of important quantum phenomena ranging from superconductivity and magnetism in condensed matter to solvent effects in chemistry. Understanding those interactions beyond mean field is a holy grail of modern sciences. AMO physics with advanced laser technologies has recently emerged as a new platform to study quantum many-body systems. One of its latest developments is the study of long-range interactions among ultracold particles to reveal the effects of many-body correlations. Rydberg atoms distinguish themselves by their large dipole moments and tunability of dipolar interactions. Most of ultracold Rydberg experiments have been performed with narrow-band lasers in the Rydberg blockade regime. Here we demonstrate an ultracold Rydberg gas in a complementary regime, where electronic coherence is created using a broadband picosecond laser pulse, thus circumventing the Rydberg blockade to induce strong many-body correlations. The effects of long-range Rydberg interactions have been investigated by time-domain Ramsey interferometry with attosecond precision. This approach allows for the real-time observation of coherent and ultrafast many-body dynamics in which the electronic coherence is modulated by the interaction-induced correlations. The modulation evolves more rapidly than expected for two-body correlations by several orders of magnitude. We have actively controlled such ultrafast many-body dynamics by tuning the principal quantum number and the population of the Rydberg state. The observed Ramsey interferograms are well reproduced by a theoretical model beyond mean-field approximation, which can be relevant to other similar many-body phenomena in condensed matter physics and chemistry. Our new approach opens a new avenue to observe and manipulate nonequilibrium dynamics of strongly-correlated quantum many-body systems on the ultrafast timescale.

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

    E-Print Network [OSTI]

    Grozdanov, Sašo

    2015-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Sašo Grozdanov; Janos Polonyi

    2015-01-26T23:59:59.000Z

    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.

  16. Combining nanocalorimetry and dynamic transmission electron microscopy for in situ characterization of materials processes under rapid heating and cooling

    SciTech Connect (OSTI)

    Grapes, Michael D., E-mail: mgrapes1@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); LaGrange, Thomas; Reed, Bryan W.; Campbell, Geoffrey H. [Condensed Matter and Materials Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Friedman, Lawrence H.; LaVan, David A., E-mail: david.lavan@nist.gov [Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Weihs, Timothy P., E-mail: weihs@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    2014-08-15T23:59:59.000Z

    Nanocalorimetry is a chip-based thermal analysis technique capable of analyzing endothermic and exothermic reactions at very high heating and cooling rates. Here, we couple a nanocalorimeter with an extremely fast in situ microstructural characterization tool to identify the physical origin of rapid enthalpic signals. More specifically, we describe the development of a system to enable in situ nanocalorimetry experiments in the dynamic transmission electron microscope (DTEM), a time-resolved TEM capable of generating images and electron diffraction patterns with exposure times of 30 ns–500 ns. The full experimental system consists of a modified nanocalorimeter sensor, a custom-built in situ nanocalorimetry holder, a data acquisition system, and the DTEM itself, and is capable of thermodynamic and microstructural characterization of reactions over a range of heating rates (10{sup 2} K/s–10{sup 5} K/s) accessible by conventional (DC) nanocalorimetry. To establish its ability to capture synchronized calorimetric and microstructural data during rapid transformations, this work describes measurements on the melting of an aluminum thin film. We were able to identify the phase transformation in both the nanocalorimetry traces and in electron diffraction patterns taken by the DTEM. Potential applications for the newly developed system are described and future system improvements are discussed.

  17. 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

  18. Dynamic and Electronic Transport Properties of DNA Translocation through Graphene Nanopores

    E-Print Network [OSTI]

    Cuniberti, Gianaurelio

    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

  19. EXPERIENCE IN REDUCING ELECTRON CLOUD AND DYNAMIC PRESSURE RISE IN WARM AND COLD REGIONS IN RHIC.

    SciTech Connect (OSTI)

    ZHANG, S.Y.; AHRENS,L.; ALLESI, J.; BAI, M.; BLASKIEWICZ, M.; CAMERON, P.; CONNOLLY, R.; DREES, A.; FISCHER, W.; GULLOTTA, J.; HE, P.; HSEUH, H.C.; HUANG, H.; LEE, R.; LITVINENKO, V.; MACKAY, W.W.; MONTAG, C.; NICOLETTI, A.; OERTER, B.; PILAT, F.; PTITSYN, V.; ROSER, T.; SATOGATA, T.; SMART, L.; SYNDSTRUP, L.; TEPIKIAN, S.; THIEBERGER, P.; TRBOJEVIC, D.; WEI, J.; ZENO, K.

    2006-06-23T23:59:59.000Z

    The large scale application of non-evaporable getter coating in RHIC has been effective in reducing the electron cloud. Since beams with higher intensity and smaller bunch spacing became possible in operation, the emittance growth is of concern. Study results are reported together with experiences of machine improvements: saturated NEG coatings, anti-grazing ridges in warm sections, and the pre-pumping in cryogenic regions.

  20. Calibration and Testing of a Water Model for Simulation of the Molecular Dynamics of Proteins and Nucleic Acids in Solution

    E-Print Network [OSTI]

    Levitt, Michael

    Calibration and Testing of a Water Model for Simulation of the Molecular Dynamics of Proteins important in biological macromolecules, where fewer experimental results are available for calibration. Our

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

    SciTech Connect (OSTI)

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

    1988-11-07T23:59:59.000Z

    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.

  2. Statistical mechanics and Vlasov equation allow for a simplified hamiltonian description of single pass free electron laser saturated dynamics

    E-Print Network [OSTI]

    Andrea Antoniazzi; Yves Elskens; Duccio Fanelli; Stefano Ruffo

    2006-01-17T23:59:59.000Z

    A reduced Hamiltonian formulation to reproduce the saturated regime of a single pass free electron laser, around perfect tuning, is here discussed. Asymptotically, $N\\_m$ particles are found to organize in a dense cluster, that evolves as an individual massive unit. The remaining particles fill the surrounding uniform sea, spanning a finite portion of phase space, approximately delimited by the average momenta $\\omega\\_+$ and $\\omega\\_-$. These quantities enter the model as external parameters, which can be self-consistently determined within the proposed theoretical framework. To this aim, we make use of a statistical mechanics treatment of the Vlasov equation, that governs the initial amplification process. Simulations of the reduced dynamics are shown to successfully capture the oscillating regime observed within the original $N$-body picture.

  3. Ultrafast transmission electron microscopy on dynamic process of a CDW transition in 1T-TaSe2

    E-Print Network [OSTI]

    Sun, Shuaishuai; Li, Zhongwen; Cao, Gaolong; Liu, Y; Lu, W J; Sun, Y P; Tian, Huanfang; HuaixinYang,; Li, Jianqi

    2015-01-01T23:59:59.000Z

    Four-dimensional ultrafast transmission electron microscopy (4D-UTEM) measurements reveal a rich variety of structural dynamic phenomena at a phase transition in the charge-density-wave (CDW) 1T-TaSe2. Through the photoexcitation, remarkable changes on both the CDW intensity and orientation are clearly observed associated with the transformation from a commensurate (C) into an incommensurate (IC) phase in a time-scale of about 3 ps. Moreover, the transient states show up a notable "structurally isosbestic point" at a wave vector of qiso where the C and IC phases yield their diffracting efficiencies in an equally ratio. This fact demonstrates that the crystal planes parallel to qiso adopts visibly common structural features in these two CDW phases. The second-order characters observed in this nonequilibrium phase transition have been also analyzed based on the time-resolved structural data.

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

    SciTech Connect (OSTI)

    Dutta, Prabir K.

    2001-09-30T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  6. Electron spin resonance investigation of Mn^{2+} ions and their dynamics in manganese doped SrTiO_3

    E-Print Network [OSTI]

    V. V. Laguta; I. V. Kondakova; I. P. Bykov; M. D. Glinchuk; P. M. Vilarinho; A. Tkach; L. Jastrabik

    2007-02-28T23:59:59.000Z

    Using electron spin resonance, lattice position and dynamic properties of Mn2+ ions were studied in 0.5 and 2 % manganese doped SrTiO3 ceramics prepared by conventional mixed oxide method. The measurements showed that Mn2+ ions substitute preferably up to 97 % for Sr if the ceramics is prepared with a deficit of Sr ions. Motional narrowing of the Mn2+ ESR spectrum was observed when temperature increases from 120 K to 240-250 K that was explained as a manifestation of off-center position of this ion at the Sr site. From the analysis of the ESR spectra the activation energy Ea = 86 mV and frequency factor 1/?0 ? (2-10)x10^(-14) 1/s for jumping of the impurity between symmetrical off-center positions were determined. Both values are in agreement with those derived previously from dielectric relaxation. This proves the origin of dielectric anomalies in SrTiO3:Mn as those produced by the reorientation dynamics of Mn2+ dipoles.

  7. Molecular dynamic simulations of electric microfield distributions in a nonideal electron-positron plasma

    SciTech Connect (OSTI)

    Sadykova, S. P.; Ebeling, W.; Sokolov, I. M. [Humboldt-Universitaet zu Berlin (Germany); Valuev, I. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2010-12-15T23:59:59.000Z

    A symmetric model of a two-component plasma is considered and the distributions of electric microfields acting on charged and neutral particles are calculated using the method of molecular dynamics at a fixed temperature of T = 30000 K and different values of the coupling parameter 0.2 {<=} {Gamma} {<=} 1.2. Changes in these distributions with varying {Gamma} are discussed. Special attention is paid to the behavior of the distribution tails. The behavior of these tails at a neutral point is shown to agree with the tails of the Holtsmark distribution, whereas the tails of the distribution at a charge are considerably heavier and are characterized by the exponent that varies within the range from -2.2 up to -1.8 as {Gamma} increases.

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

    SciTech Connect (OSTI)

    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

    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.

  9. Torque for electron spin induced by electron permanent electric dipole moment

    SciTech Connect (OSTI)

    Senami, Masato, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)

    2014-10-06T23:59:59.000Z

    The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

  10. An infrared free electron laser system for the proposed Chemical Dynamics Research Laboratory at LBL based on a 500 MHz superconducting linac

    SciTech Connect (OSTI)

    Kim, K.J.; Byrns, R.; Chattopadhyay, S.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

    1992-09-01T23:59:59.000Z

    We describe a new design of the Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Research Laboratory (CDRL) at LBL. The design and choice of parameters are dictated by the unique requirements of the CDRL scientific program. The accelerator system is based on the 500 MHz superconducting cavity technology to achieve a wavelength stability of 10{sup {minus}4}.

  11. An infrared free electron laser system for the proposed Chemical Dynamics Research Laboratory at LBL based on a 500 MHz superconducting linac

    SciTech Connect (OSTI)

    Kim, K.J.; Byrns, R.; Chattopadhyay, S.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

    1992-09-01T23:59:59.000Z

    We describe a new design of the Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Research Laboratory (CDRL) at LBL. The design and choice of parameters are dictated by the unique requirements of the CDRL scientific program. The accelerator system is based on the 500 MHz superconducting cavity technology to achieve a wavelength stability of 10[sup [minus]4].

  12. Clustering Dynamics of the Metal-Benzene Sandwich Complex: The Role of Microscopic Structure of the Solute In the Bis(6-benzene)chromium Arn Clusters (n ) 1-15)

    E-Print Network [OSTI]

    Kim, Sang Kyu

    Clustering Dynamics of the Metal-Benzene Sandwich Complex: The Role of Microscopic Structure of the Solute In the Bis(6-benzene)chromium ·Arn Clusters (n ) 1-15) Kyo-Won Choi, Sunyoung Choi, Doo-Sik AhnVised Manuscript ReceiVed: June 25, 2008 Ar clustering dynamics around the metal-benzene sandwich complex, bis(6

  13. Electrical/Electronic Engineering

    E-Print Network [OSTI]

    Berdichevsky, Victor

    Electrical/Electronic Engineering Technology The Division of Engineering of Science in Electrical/Electronic Engineering Technology Get ready for a dynamic career in Electrical/Electronic Engineering Technology. Possible applications

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

    E-Print Network [OSTI]

    Tian You Fan

    2012-10-05T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Luo, Tianhuan; /Indiana U.

    2011-08-01T23:59:59.000Z

    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.

  16. Probing Reaction Dynamics of Transition-Metal Complexes in Solution via Time-Resolved Soft X-ray Spectroscopy

    SciTech Connect (OSTI)

    Huse, Nils; Kim, Tae Kyu; Khalil, Munira; Jamula, Lindsey; McCusker, James K.; Schoenlein, Robert W.

    2010-05-02T23:59:59.000Z

    We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding.

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

    SciTech Connect (OSTI)

    Lu, Ping

    2014-10-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  19. Electron-ion dynamics in laser-assisted desorption of hydrogen atoms from H-Si(111) surface

    SciTech Connect (OSTI)

    Bubin, Sergiy; Varga, Kalman [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    2011-09-15T23:59:59.000Z

    In the framework of real time real space time-dependent density functional theory we have studied the electron-ion dynamics of a hydrogen-terminated silicon surface H-Si(111) subjected to intense laser irradiation. Two surface fragments of different sizes have been used in the simulations. When the intensity and duration of the laser exceed certain levels (which depend on the wavelength) we observe the desorption of the hydrogen atoms, while the underlying silicon layer remains essentially undamaged. Upon further increase of the laser intensity, the chemical bonds between silicon atoms break as well. The results of the simulations suggest that with an appropriate choice of laser parameters it should be possible to remove the hydrogen layer from the H-Si(111) surface in a matter of a few tens of femtoseconds. We have also observed that at high laser field intensities (2-4 V/A in this work) the desorption occurs even when the laser frequency is smaller than the optical gap of the silicon surface fragments. Therefore, nonlinear phenomena must play an essential role in such desorption processes.

  20. Effect of pulse error accumulation on dynamical decoupling of the electron spins of phosphorus donors in silicon

    E-Print Network [OSTI]

    Zhi-Hui Wang; Wenxian Zhang; A. M. Tyryshkin; S. A. Lyon; J. W. Ager; E. E. Haller; V. V. Dobrovitski

    2012-01-03T23:59:59.000Z

    Dynamical decoupling (DD) is an efficient tool for preserving quantum coherence in solid-state spin systems. However, the imperfections of real pulses can ruin the performance of long DD sequences. We investigate the accumulation and compensation of different pulse errors in DD using the electron spins of phosphorus donors in silicon as a test system. We study periodic DD sequences (PDD) based on spin rotations about two perpendicular axes, and their concatenated and symmetrized versions. We show that pulse errors may quickly destroy some spin states, but maintain other states with high fidelity over long times. Pulse sequences based on spin rotations about $x$ and $y$ axes outperform those based on $x$ and $z$ axes due to the accumulation of pulse errors. Concatenation provides an efficient way to suppress the impact of pulse errors, and can maintain high fidelity for all spin components: pulse errors do not accumulate (to first order) as the concatenation level increases, despite the exponential increase in the number of pulses. Our theoretical model gives a clear qualitative picture of the error accumulation, and produces results in quantitative agreement with the experiments.

  1. 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)

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

    1987-03-12T23:59:59.000Z

    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.

  2. SOLUTION-PROCESSED INORGANIC ELECTRONICS

    E-Print Network [OSTI]

    Bakhishev, Teymur

    2011-01-01T23:59:59.000Z

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

  3. SOLUTION-PROCESSED INORGANIC ELECTRONICS

    E-Print Network [OSTI]

    Bakhishev, Teymur

    2011-01-01T23:59:59.000Z

    Graphene Conductors .. 41 Fabrication .. 44 Printing Conditions Optimization 44 ii Experimental Setup and Sample Preparation

  4. High-precision gigahertz-to-terahertz spectroscopy of aqueous salt solutions as a probe of the femtosecond-to-picosecond dynamics of liquid water

    E-Print Network [OSTI]

    Vinh, N Q; Allen, S James; George, D K; Rahmani, A J; Plaxco, Kevin W

    2015-01-01T23:59:59.000Z

    Because it is sensitive to fluctuations occurring over femtoseconds to picoseconds, gigahertz-to-terahertz dielectric relaxation spectroscopy can provide a valuable window into water's most rapid intermolecular motions. In response, we have built a vector network analyzer dielectric spectrometer capable of measuring absorbance and index of refraction in this frequency regime with unprecedented precision. Using this to determine the complex dielectric response of water and aqueous salt solutions from 5.9 GHz to 1.12 THz (which we provide in the SI), we have obtained strong new constraints on theories of water's collective dynamics. For example, while the salt-dependencies we observe for water's two slower relaxations (8 and 1 ps) are easily reconciled with suggestions that they arise due to rotations of fully and partially hydrogen bonded molecules, respectively, the salt-dependence of the fastest relaxation (180 fs) appears difficult to reconcile with its prior assignment to liberations of single hydrogen bon...

  5. Rapid Laser Induced Crystallization of Amorphous NiTi Films Observed by Nanosecond Dynamic Transmission Electron Microscopy (DTEM)

    SciTech Connect (OSTI)

    LaGrange, T; Campbell, G H; Browning, N D; Reed, B W; Grummon, D S

    2010-03-01T23:59:59.000Z

    The crystallization processes of the as-deposited, amorphous NiTi thin films have been studied in detail using techniques such as differential scanning calorimetry and, in-situ TEM. The kinetic data have been analyzed in terms of Johnson-Mehl-Avrami-Kolomogrov (JMAK) semi-empirical formula. The kinetic parameters determined from this analysis have been useful in defining process control parameters for tailoring microstructural features and shape memory properties. Due to the commercial push to shrink thin film-based devices, unique processing techniques have been developed using laser-based annealing to spatially control the microstructure evolution down to sub-micron levels. Nanosecond, pulse laser annealing is particularly attractive since it limits the amount of peripheral heating and unwanted microstructural changes to underlying or surrounding material. However, crystallization under pulsed laser irradiation can differ significantly from conventional thermal annealing, e.g., slow heating in a furnace. This is especially true for amorphous NiTi materials and relevant for shape memory thin film based microelectromechanical systems (MEMS) applications. There is little to no data on the crystallization kinetics of NiTi under pulsed laser irradiation, primarily due to the high crystallization rates intrinsic to high temperature annealing and the spatial and temporal resolution limits of standard techniques. However, with the high time and spatial resolution capabilities of the dynamic transmission electron microscope (DTEM) constructed at Lawrence Livermore National Laboratory, the rapid nucleation events occurring from pulsed laser irradiation can be directly observed and nucleation rates can be quantified. This paper briefly explains the DTEM approach and how it used to investigate the pulsed laser induced crystallization processes in NiTi and to determine kinetic parameters.

  6. Electronic excitation spectra of molecules in solution calculated using the symmetry-adapted cluster-configuration interaction method in the polarizable continuum model with perturbative approach

    SciTech Connect (OSTI)

    Fukuda, Ryoichi, E-mail: fukuda@ims.ac.jp; Ehara, Masahiro [Institute for Molecular Science and Research Center for Computational Science, 38 Nishigo-naka, Myodaiji, Okazaki 444-8585 (Japan) [Institute for Molecular Science and Research Center for Computational Science, 38 Nishigo-naka, Myodaiji, Okazaki 444-8585 (Japan); Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Kyoto University Katsura, Kyoto 615-8520 (Japan); Cammi, Roberto, E-mail: roberto.cammi@unipr.it [Dipartimento di Chimica Università di Parma, Viale delle Scienze, 17/A, 1-43100 Parma (Italy)] [Dipartimento di Chimica Università di Parma, Viale delle Scienze, 17/A, 1-43100 Parma (Italy)

    2014-02-14T23:59:59.000Z

    A perturbative approximation of the state specific polarizable continuum model (PCM) symmetry-adapted cluster-configuration interaction (SAC-CI) method is proposed for efficient calculations of the electronic excitations and absorption spectra of molecules in solutions. This first-order PCM SAC-CI method considers the solvent effects on the energies of excited states up to the first-order with using the zeroth-order wavefunctions. This method can avoid the costly iterative procedure of the self-consistent reaction field calculations. The first-order PCM SAC-CI calculations well reproduce the results obtained by the iterative method for various types of excitations of molecules in polar and nonpolar solvents. The first-order contribution is significant for the excitation energies. The results obtained by the zeroth-order PCM SAC-CI, which considers the fixed ground-state reaction field for the excited-state calculations, are deviated from the results by the iterative method about 0.1 eV, and the zeroth-order PCM SAC-CI cannot predict even the direction of solvent shifts in n-hexane for many cases. The first-order PCM SAC-CI is applied to studying the solvatochromisms of (2,2{sup ?}-bipyridine)tetracarbonyltungsten [W(CO){sub 4}(bpy), bpy = 2,2{sup ?}-bipyridine] and bis(pentacarbonyltungsten)pyrazine [(OC){sub 5}W(pyz)W(CO){sub 5}, pyz = pyrazine]. The SAC-CI calculations reveal the detailed character of the excited states and the mechanisms of solvent shifts. The energies of metal to ligand charge transfer states are significantly sensitive to solvents. The first-order PCM SAC-CI well reproduces the observed absorption spectra of the tungsten carbonyl complexes in several solvents.

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

    SciTech Connect (OSTI)

    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

    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.

  8. A general three-state model with biased population replacement: analytical solution and application to language dynamics

    E-Print Network [OSTI]

    Colaiori, Francesca; Cuskley, Christine F; Loreto, Vittorio; Pugliese, Martina; Tria, Francesca

    2014-01-01T23:59:59.000Z

    Empirical evidence shows that the rate of irregular usage of English verbs exhibits discontinuity as a function of their frequency: the most frequent verbs tend to be totally irregular. We aim to qualitatively understand the origin of this feature by studying simple agent--based models of language dynamics, where each agent adopts an inflectional state for a verb and may change it upon interaction with other agents. At the same time, agents are replaced at some rate by new agents adopting the regular form. In models with only two inflectional states (regular and irregular), we observe that either all verbs regularize irrespective of their frequency, or a continuous transition occurs between a low frequency state where the lemma becomes fully regular, and a high frequency one where both forms coexist. Introducing a third (mixed) state, wherein agents may use either form, we find that a third, qualitatively different behavior may emerge, namely, a discontinuous transition in frequency. We introduce and solve an...

  9. Efficient drug delivery mechanisms of liposomes with tethered biopolymer brushes in aqueous solution using dissipative particle dynamics simulations

    E-Print Network [OSTI]

    Goicochea, A Gama; Klapp, J; Pastorino, C

    2013-01-01T23:59:59.000Z

    We undertake the investigation of model liposomes covered with polyethylene glycol brushes as a case study for the mechanisms of efficient drug delivery in biologically relevant situations.Extensive non- equilibrium, coarse grained dissipative particle dynamics simulations of polymer brushes of various lengths and shear rates are performed, having in mind polymer brushes covering the surfaces of drug carrying liposomes in the human circulatory system.In particular, we calculate the viscosity and the friction coefficient for polymer brushes as functions of the shear rate and polymerization degree under theta solvent conditions, and find that the liposome brushes experience considerable shear thinning at large shear rates. The viscosity is shown to obey a scaling law at high shear rate irrespective of the brushes degree of polymerization. A new general scaling relation is obtained for the viscosity at high shear rates. These results reproduce very well trends in recent drug delivering experiments.

  10. Accelerated, energy-conserving BornOppenheimer molecular dynamics via Fock matrix extrapolation

    E-Print Network [OSTI]

    Herbert, John

    in order to accelerate convergence of the electronic structure calculations, can suffer from systematic­Oppenheimer molecular dynamics calculations, especially those that exploit information retained from previous time steps, on a potential energy surface obtained by ``on-the-fly'' solution of the quantum-mechanical electronic structure

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

    E-Print Network [OSTI]

    Glowacki, David R; Harvey, Jeremy N

    2014-01-01T23:59:59.000Z

    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...

  12. Ultrafast probing of the x-ray-induced lattice and electron dynamics in graphite at atomic-resolution

    SciTech Connect (OSTI)

    Hau-Riege, S

    2010-10-07T23:59:59.000Z

    We used LCLS pulses to excite thin-film and bulk graphite with various different microstructures, and probed the ultrafast ion and electron dynamics through Bragg and x-ray Thomson scattering (XRTS). We pioneered XRTS at LCLS, making this technique viable for other users. We demonstrated for the first time that the LCLS can be used to characterize warm-dense-matter through Bragg and x-ray Thomson scattering. The warm-dense-matter conditions were created using the LCLS beam. Representative examples of the results are shown in the Figure above. In our experiment, we utilized simultaneously both Bragg and two Thomson spectrometers. The Bragg measurements as a function of x-ray fluence and pulse length allows us to characterize the onset of atomic motion at 2 keV with the highest resolution to date. The Bragg detector was positioned in back-reflection, providing us access to scattering data with large scattering vectors (nearly 4{pi}/{lambda}). We found a clear difference between the atomic dynamics for 70 and 300 fs pulses, and we are currently in the process of comparing these results to our models. The outcome of this comparison will have important consequences for ultrafast diffractive imaging, for which it is still not clear if atomic resolution can truly be achieved. The backward x-ray Thomson scattering data suggests that the average graphite temperature and ionization was 10 eV and 1.0, respectively, which agrees with our models. In the forward scattering data, we observed an inelastic feature in the Thomson spectrum that our models currently do not reproduce, so there is food for thought. We are in the process of writing these results up. Depending on if we can combine the Bragg and Thomson data or not, we plan to publish them in a single paper (e.g. Nature or Science) or as two separate papers (e.g. two Phys. Rev. Lett.). We will present the first analysis of the results at the APS Plasma Meeting in November 2010. We had a fantastic experience performing our experiment at the LCLS, and we are grateful to the beamline scientists and all the support personnel for enabling this experiment. A major hurdle was the very short transition time of two days, which despite all our preparations did not give us sufficient time to test the full system before the start of the beam time. We further were not able to make optimal use of the beam time since we had to exchange samples in the middle of the 36-hours shift. An additional 12-hours break could have avoided this. Finally, our experiment would have benefitted from the best possible focus, but 5 shifts do not allow performing the experiment while fine-tuning the focusing optics.

  13. Dynamic

    Office of Legacy Management (LM)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7111AWell: Gas productionDynamic , and Static ,

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

    SciTech Connect (OSTI)

    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. [Universität Siegen, D-57068 Siegen (Germany)] [Universität 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 Universität Dresden, D-01062 Dresden (Germany)

    2014-03-15T23:59:59.000Z

    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.

  15. Qualitative Aspects of the Solutions of a Mathematical Model for the Dynamic Analysis of the Reversible Chemical Reaction SO2(g)+1/2O2(g)SO3(g) in a Catalytic Reactor

    E-Print Network [OSTI]

    Angulo Wilfredo; Contreras Joyne

    2014-12-19T23:59:59.000Z

    We present some qualitative aspects concerning the solution to the mathematical model describing the dynamical behavior of the reversible chemical reaction SO2(g)+1/2O2(g)SO3(g) carried out in a catalytic reactor used in the process of sulfuric acid production.

  16. 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

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

    E-Print Network [OSTI]

    Peter Leifer; Taha Massalha

    2010-08-23T23:59:59.000Z

    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.

  18. Design of a superconducting linear accelerator for an Infrared Free Electron Laser of the proposed Chemical Dynamics Research Laboratory at LBL

    SciTech Connect (OSTI)

    Chattopadhyay, S.; Byrns, R.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Kim, K.J.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

    1992-08-01T23:59:59.000Z

    An accelerator complex has recently been designed at LBL as part of an Infrared Free Electron Laser facility in support of a proposed Chemical Dynamics Research Laboratory. We will outline the choice of parameters and design philosophy, which are strongly driven by the demand of reliable and spectrally stable operation of the FEL for very special scientific experiments. The design is based on a 500 MHz recirculating superconducting electron linac with highest energy reach of about 60 MeV. The accelerator is injected with beams prepared by a specially designed gun-buncher system and incorporates a near-isochronous and achromatic recirculation line tunable over a wide range of beam energies. The stability issues considered to arrive at the specific design will be outlined.

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

    E-Print Network [OSTI]

    Chu, Shih-I; Zhou, Zhongyuan

    2009-10-27T23:59:59.000Z

    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...

  20. 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...

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

    E-Print Network [OSTI]

    Iyengar, Srinivasan S.

    2011-01-01T23:59:59.000Z

    systems6­16 and solar energy conversion and storage.55­57 The intensity of current research effort, and external fields Alexander B. Pacheco and Srinivasan S. Iyengara) Department of Chemistry and Department solvated electron chemistry30­41 plays an impor- tant role. In materials chemistry, active research

  2. Introduction to Structure and Dynamics: Inaugural Issue

    E-Print Network [OSTI]

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

    2005-01-01T23:59:59.000Z

    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

  3. Conjugated Polymer Design and Engineering for Organic Electronics

    E-Print Network [OSTI]

    Woo, Claire Hoi Kar

    2011-01-01T23:59:59.000Z

    W. ; Forrest, S. R. Organic Electronics 2003, 4, 77-87. (24)Aspects of Organic Electronics: From Fundamentals toof solution-processed organic electronics rapidly advancing,

  4. Energetics of Electron Transfer at the Nanocrystalline Titanium Dioxide Semiconductor/ Aqueous Solution Interface: pH Invariance of the Metal-Based Formal Potential of a

    E-Print Network [OSTI]

    Energetics of Electron Transfer at the Nanocrystalline Titanium Dioxide Semiconductor/ Aqueous,4-(CH2PO3)-2,2-bipyridine)3 10-, bound to a nanocrystalline titanium dioxide film shows energy (ECB) of the underlying semiconductor electrode in response to the same environmental

  5. Theory of dynamic nuclear polarization and feedback in quantum dots

    E-Print Network [OSTI]

    Sophia E. Economou; Edwin Barnes

    2014-04-06T23:59:59.000Z

    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.

  6. 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

  7. 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...

  8. 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)

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

    1986-10-10T23:59:59.000Z

    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.

  9. 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...

  10. Laser-induced electron localization in H$_2^+$: Mixed quantum-classical dynamics based on the exact time-dependent potential energy surface

    E-Print Network [OSTI]

    Suzuki, Yasumitsu; Maitra, Neepa T; Gross, E K U

    2015-01-01T23:59:59.000Z

    We study the exact nuclear time-dependent potential energy surface (TDPES) for laser-induced electron localization with a view to eventually developing a mixed quantum-classical dynamics method for strong-field processes. The TDPES is defined within the framework of the exact factorization [A. Abedi, N. T. Maitra, and E. K. U. Gross, Phys. Rev. Lett. 105, 123002 (2010)] and contains the exact effect of the couplings to the electronic subsystem and to any external fields within a scalar potential. We compare its features with those of the quasistatic potential energy surfaces (QSPES) often used to analyse strong-field processes. We show that the gauge-independent component of the TDPES has a mean-field-like character very close to the density-weighted average of the QSPESs. Oscillations in this component are smoothened out by the gauge-dependent component, and both components are needed to yield the correct force on the nuclei. Once the localization begins to set in, the gradient of the exact TDPES tracks one ...

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

    SciTech Connect (OSTI)

    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

    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.

  12. Heat Transfer Study of Polymer Solutions with Different Rigidities

    E-Print Network [OSTI]

    Huang, Yao

    2014-05-08T23:59:59.000Z

    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...

  13. 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)

    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

    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.

  14. An Infrared Free Electron Laser System for the Proposed Chemical Dynamics Research Laboratory at LBL Based on a 500 MHz Superconducting Linac

    E-Print Network [OSTI]

    Kim, K.-J.

    2011-01-01T23:59:59.000Z

    International Free Electron Laser Conference, Kobe, Japan,2 i An Infrared Free Electron Laser System for the ProposedDE93 004723 AN INFRARED FREE ELECTRON LASER SYSTEM FOR THE

  15. Design of a Superconducting Linear Accelerator for an Infrared Free Electron Laser of the Proposed Chemical Dynamics Research Laboratory at LBL

    E-Print Network [OSTI]

    Chattopadhyay, S.

    2011-01-01T23:59:59.000Z

    see "An Infrared Free-Electron Laser for CDRL," LBL Pub-FOR AN INFRARED FREE ELECTRON LASER OF 1HE PROPOSED CHEMICALFOR AN INFRARED FREE ELECTRON LASER OF THE PROPOSED CHEMICAL

  16. 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)

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

    1992-10-29T23:59:59.000Z

    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.

  17. 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)

    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

    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.

  18. 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)

    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

    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.

  19. In situ investigation of explosive crystallization in a-Ge: Experimental determination of the interface response function using dynamic transmission electron microscopy

    SciTech Connect (OSTI)

    Nikolova, Liliya; MacLeod, Jennifer M.; Ibrahim, Heide [Centre Énergie, Matériaux, Télécommunications, Institut National de la Recherche Scientifique, 1650 Lionel Boulet boulevard, Varennes, Quebec J3X 1S2 (Canada); Stern, Mark J.; Siwick, Bradley J., E-mail: rosei@emt.inrs.ca, E-mail: lagrange2@llnl.gov, E-mail: bradley.siwick@mcgill.ca [Center for the Physics of Materials, Departments of Physics and Chemistry, McGill University, 801 Sherbrooke St. W., Montreal, Quebec H3A 2K6 (Canada); Reed, Bryan W.; Campbell, Geoffrey H.; LaGrange, Thomas, E-mail: rosei@emt.inrs.ca, E-mail: lagrange2@llnl.gov, E-mail: bradley.siwick@mcgill.ca [Condensed Matter and Materials Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); Rosei, Federico, E-mail: rosei@emt.inrs.ca, E-mail: lagrange2@llnl.gov, E-mail: bradley.siwick@mcgill.ca [Centre Énergie, Matériaux, Télécommunications, Institut National de la Recherche Scientifique, 1650 Lionel Boulet boulevard, Varennes, Quebec J3X 1S2 (Canada); Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. W., Montreal, Quebec H3A 2K6 (Canada)

    2014-09-07T23:59:59.000Z

    The crystallization of amorphous semiconductors is a strongly exothermic process. Once initiated the release of latent heat can be sufficient to drive a self-sustaining crystallization front through the material in a manner that has been described as explosive. Here, we perform a quantitative in situ study of explosive crystallization in amorphous germanium using dynamic transmission electron microscopy. Direct observations of the speed of the explosive crystallization front as it evolves along a laser-imprinted temperature gradient are used to experimentally determine the complete interface response function (i.e., the temperature-dependent front propagation speed) for this process, which reaches a peak of 16?m/s. Fitting to the Frenkel-Wilson kinetic law demonstrates that the diffusivity of the material locally/immediately in advance of the explosive crystallization front is inconsistent with those of a liquid phase. This result suggests a modification to the liquid-mediated mechanism commonly used to describe this process that replaces the phase change at the leading amorphous-liquid interface with a change in bonding character (from covalent to metallic) occurring in the hot amorphous material.

  20. 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]

    van Stokkum, Ivo

    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

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

    SciTech Connect (OSTI)

    Duan, Yuhua; Parlinski, K.

    2011-01-01T23:59:59.000Z

    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.

  2. 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)

    Duan, Yuhua

    2014-01-01T23:59:59.000Z

    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}.

  3. 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)

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

    2013-12-15T23:59:59.000Z

    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.

  4. 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)

    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

    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.

  5. Electron thermal effect on linear and nonlinear coupled Shukla-Varma and convective cell modes in dust-contaminated magnetoplasma

    SciTech Connect (OSTI)

    Masood, W. [TPPD, PINSTECH, P. O. Nilore, Islamabad 44000, Pakistan and National Center for Physics (NCP), Islamabad 45320 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2010-11-15T23:59:59.000Z

    Linear and nonlinear properties of coupled Shukla-Varma (SV) and convective cell modes in the presence of electron thermal effects are studied in a nonuniform magnetoplasma composed of electrons, ions, and extremely massive and negatively charged immobile dust grains. In the linear case, the modified dispersion relation is given and, in the nonlinear case, stationary solutions of the nonlinear equations that govern the dynamics of coupled SV and convective cell modes are obtained. It is found that electrostatic dipolar and vortex street type solutions can appear in such a plasma. The relevance of the present investigation with regard to the Earth's mesosphere as well as in ionospheric plasmas is also pointed out.

  6. A Review on Ab Initio Approaches for Multielectron Dynamics

    E-Print Network [OSTI]

    Ishikawa, Kenichi L

    2015-01-01T23:59:59.000Z

    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...

  7. 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...

  8. Electron localization following attosecond molecular photoionization

    E-Print Network [OSTI]

    Kling, Matthias

    - 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

  9. Explicit Correlated Exciton-Vibrational Dynamics of the FMO Complex

    E-Print Network [OSTI]

    Schulze, Jan

    2015-01-01T23:59:59.000Z

    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.

  10. Solvated electron lithium electrode for high energy density battery

    SciTech Connect (OSTI)

    Sammels, A.F.

    1987-08-04T23:59:59.000Z

    A solvated electron lithium negative electrode is described containing: containment means holding a solution of lithium dissolved in liquid ammonia to form a solvated electron solution, the solvated electron solution contacting a lithium intercalating membrane and providing lithium to the intercalating membrane during discharge and accepting it from the intercalating membrane during charge.

  11. Electronic and Vibrational Properties of Low-Dimensional Heterogeneous Systems: Materials and Device Perspectives

    E-Print Network [OSTI]

    Neupane, Mahesh Raj

    2015-01-01T23:59:59.000Z

    electronic structure calculation package QUANTUM ESPRESSO [311]. MD Calculation Molecular dynamics (

  12. Ab initio simulations of two-dimensional electronic spectra: The SOS//QM/MM approach

    E-Print Network [OSTI]

    Rivalta, I; Nenov, A; Cerullo, G; Mukamel, S; Garavelli, M; Garavelli, M

    2013-01-01T23:59:59.000Z

    calculations. Conclusions Two-dimensional electronic spectroscopy holds great potential for studying structure, dynamics,

  13. Uranyl fluoride luminescence in acidic aqueous solutions

    SciTech Connect (OSTI)

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

    1996-08-01T23:59:59.000Z

    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}.

  14. Correlated exciton dynamics in semiconductor nanostructures

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

    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 ...

  15. 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)

    Lü, 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

    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.

  16. 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]

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

    2013-07-31T23:59:59.000Z

    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.

  17. EIGENMODE ANALYSIS OF OPTICAL GUIDING IN FREE ELECTRON LASERS

    E-Print Network [OSTI]

    Xie, M.

    2010-01-01T23:59:59.000Z

    of Optical Guiding in Free Electron Lasers", Department ofGuided Mode Solutions in Free Electron Lasers", "High GainResonator in Free Electron Lasers", to be published. P.

  18. Parallel Solutions of Partial Differential Equations with Adaptive Multigrid Methods

    E-Print Network [OSTI]

    Wieners, Christian

    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

  19. Chaotic electron dynamics around a single elliptically shaped antidot High Magnetic Field Laboratory CNRS, Boite Postale 166, F-38042 Grenoble, France

    E-Print Network [OSTI]

    Gusev, Guennady

    , Boite Postale 166, F-38042 Grenoble, France J. C. Portal High Magnetic Field Laboratory CNRS, Boite, Russia Received 30 April 1996 The classical dynamics of a charged particle colliding ballistically around

  20. Two-element free-electron lasers

    SciTech Connect (OSTI)

    Shih, C.; Yariv, A.

    1980-02-01T23:59:59.000Z

    The interaction between the electrons and the radiation in a free-electrons laser leads to a shift and a spread of the electron velocity distribution. The electron dynamics of a two-element system are studied in the small signal region. It is found that the efficiency and gain can be increased through introduction of an adjustable drift distance between two identical wigglers.

  1. Electron radiography

    DOE Patents [OSTI]

    Merrill, Frank E.; Morris, Christopher

    2005-05-17T23:59:59.000Z

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  2. Electronic Excitations Transform Structure of Ceramics | ornl...

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

    & Ti atoms; O vacancies, VO, are small spheres with blue cores. Ab initio molecular dynamics calculations reveal that electronic excitations induce a structural instability that...

  3. Quantum effective potential, electron transport and conformons in biopolymers

    E-Print Network [OSTI]

    Rossen Dandoloff; Radha Balakrishnan

    2005-05-29T23:59:59.000Z

    In the Kirchhoff model of a biopolymer, conformation dynamics can be described in terms of solitary waves, for certain special cross-section asymmetries. Applying this to the problem of electron transport, we show that the quantum effective potential arising due to the bends and twists of the polymer enables us to formalize and quantify the concept of a {\\it conformon} that has been hypothesized in biology. Its connection to the soliton solution of the cubic nonlinear Schr\\"{o}dinger equation emerges in a natural fashion.

  4. Ultrafast infrared studies of complex ligand rearrangements in solution

    SciTech Connect (OSTI)

    Payne, Christine K.

    2003-05-31T23:59:59.000Z

    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.

  5. 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...

  6. The encapsulation of hydrophobic drugs in Pluronic F127 micelles: the effects of drug hydrophobicity, solution temperature and pH

    E-Print Network [OSTI]

    Rajib Basak; Ranjini Bandyopadhyay

    2014-06-27T23:59:59.000Z

    Three drugs, Ibuprofen, Aspirin and Erythromycin, are encapsulated in spherical Pluronic F127 micelles. The shapes and the size distributions of the micelles in dilute, aqueous solutions, with and without drugs, are ascertained using cryo- Scanning Electron Microscopy and Dynamic Light Scattering (DLS) experiments, respectively. Uptake of drugs above a threshold concentration is seen to reduce the critical micellization temperature of the solution. The mean hydrodynamic radii and polydispersities of the micelles are found to increase with decrease in temperature and in the presence of drug molecules. The hydration of the micellar core at lower temperatures is verified using fluorescence measurements. Increasing solution pH leads to the ionization of the drugs incorporated in the micellar cores. This causes rupture of the micelles and release of the drugs into the solution at the highest solution pH value of 11.36 investigated here and is studied using DLS and fluorescence spectrocopy.

  7. 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)

    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

    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.

  8. Electron-acoustic_solitary_structures_in_two-electron-temperature_plasma_with_superthermal_electrons

    E-Print Network [OSTI]

    Chen, H

    2011-01-01T23:59:59.000Z

    The propagation of nonlinear electron- acoustic waves (EAWs) in an unmagnetized collision- less plasma system consisting of a cold electron fluid, superthermal hot electrons and stationary ions is investigated. A reductive perturbation method is employed to obtain a modified Korteweg-de Vries (mKdV) equa- tion for the first-order potential. The small amplitude electron-acoustic solitary wave, e.g., soliton and dou- ble layer (DL) solutions are presented, and the effects of superthermal electrons on the nature of the solitons are also discussed. But the results shows that the weak stationary EA DLs cannot be supported by the present model.

  9. PHYSICAL REVIEW A 84, 043423 (2011) Dynamic of rescattering-electron wave packets in strong and short-wavelength laser fields

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    and short-wavelength laser fields: Roles of Coulomb potential and excited states Yanjun Chen* Beijing and molecules exposed in strong and short- wavelength (shorter than 800 nm) laser fields. Our simulations show the potential, to explain the electronic response in intense and relatively high-frequency laser fields. DOI: 10

  10. Electronic copy available at: http://ssrn.com/abstract=1493525 Title: From crude law to civil relations: the dynamics and potential resolution of

    E-Print Network [OSTI]

    Electronic copy available at: http://ssrn.com/abstract=1493525 Title: From crude law to civil and transformation of intractable conflict is presented. The formal model translates the insights of the Crude Law: http://ssrn.com/abstract=1493525 1 Running head: Crude Law and conflict From crude law to civil

  11. Electrostatic shock dynamics in superthermal plasmas

    E-Print Network [OSTI]

    Sultana, S; Kourakis, I

    2011-01-01T23:59:59.000Z

    The propagation of ion acoustic shocks in nonthermal plasmas is investigated, both analytically and numerically. An unmagnetized collisionless electron-ion plasma is considered, featuring a superthermal (non-Maxwellian) electron distribution, which is modeled by a $\\kappa$- (kappa) distribution function. Adopting a multiscale approach, it is shown that the dynamics of low-amplitude shocks is modeled by a hybrid Korteweg-de Vries -- Burgers (KdVB) equation, in which the nonlinear and dispersion coefficients are functions of the $\\kappa$ parameter, while the dissipative coefficient is a linear function of the ion viscosity. All relevant shock parameters are shown to depend on $\\kappa$: higher deviations from a pure Maxwellian behavior induce shocks which are narrower, faster and of larger amplitude. The stability profile of the kink-shaped solutions of the KdVB equation against external perturbations is investigated and the spatial profile of the shocks is found to depend upon and the role of the interplay betw...

  12. An Ab-Initio approach to the dynamics ofAn Ab-Initio approach to the dynamics of electrons and excitons in solids drivenelectrons and excitons in solids driven

    E-Print Network [OSTI]

    Marini, Andrea

    Motivations and experimental evidences #12;Pump&Probe experimentsPump&Probe experiments An ultra-short laser pulse pumpsAn ultra-short laser pulse pumps electrons in the conductionelectrons in the conduction The non and excitons in solids drivenelectrons and excitons in solids driven out-of-equilibrium by strong laser

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

    E-Print Network [OSTI]

    Ryu, Seungwan

    2013-01-01T23:59:59.000Z

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

  14. Ultrafast Strong-Field Vibrational Dynamics Studied by Femtosecond Extreme-Ultraviolet Transient Absorption Spectroscopy

    E-Print Network [OSTI]

    Hosler, Erik Robert

    2013-01-01T23:59:59.000Z

    dynamics. Tunnel ionization rate determinations are employed to model the pump, while electronic structure calculations

  15. Equilibrium and dynamics of ionic solutions

    E-Print Network [OSTI]

    Anton, Mihai

    2009-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    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

    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.

  17. Determination of the paradihlorobenzene and paradibromobenzene solid solutions nanoparticles structure via Raman spectra

    E-Print Network [OSTI]

    Korshunov, M A

    2012-01-01T23:59:59.000Z

    We measured the small frequencies Raman spectrum of the paradihlorobenzene and paradihlorobenzene solid solution nanoparticles with the size about 100 nanometers. Values of frequencies of lines decrease. The size of nanoparticles was determined by the electronic microscope. Calculations of nanoparticles structure were done using the method of molecular dynamics and histograms of nanoparticles spectra were calculated via the Dyne's method. The result is that the Raman spectrum is the sum of spectra from the central part of the nanoparticle and superficial structures with smaller concentration of paradihlorobenzene.

  18. 2010 Water & Aqueous Solutions

    SciTech Connect (OSTI)

    Dor Ben-Amotz

    2010-08-13T23:59:59.000Z

    Water covers more than two thirds of the surface of the Earth and about the same fraction of water forms the total mass of a human body. Since the early days of our civilization water has also been in the focus of technological developments, starting from converting it to wine to more modern achievements. The meeting will focus on recent advances in experimental, theoretical, and computational understanding of the behavior of the most important and fascinating liquid in a variety of situations and applications. The emphasis will be less on water properties per se than on water as a medium in which fundamental dynamic and reactive processes take place. In the following sessions, speakers will discuss the latest breakthroughs in unraveling these processes at the molecular level: Water in Solutions; Water in Motion I and II; Water in Biology I and II; Water in the Environment I and II; Water in Confined Geometries and Water in Discussion (keynote lecture and poster winners presentations).

  19. 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)

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

    2014-02-07T23:59:59.000Z

    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.

  20. Liquid-state polaron theory of the hydrated electron revisited

    E-Print Network [OSTI]

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

    2014-12-25T23:59:59.000Z

    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.

  1. Development of the doppler electron velocimeter: theory.

    SciTech Connect (OSTI)

    Reu, Phillip L.

    2007-03-01T23:59:59.000Z

    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.

  2. A Note on Tubular Brane Dynamics

    E-Print Network [OSTI]

    Jose J. Blanco-Pillado

    2005-04-19T23:59:59.000Z

    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.

  3. Dynamic coupling drives conformational evolution of branched...

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

    Materials Characterization Dynamic coupling drives conformational evolution of branched polymers in solutions March 06, 2015 Inter-particle collision time (filled circles) and...

  4. Approximation of the Time-Dependent Electronic Schrodinger Equation by

    E-Print Network [OSTI]

    Koch, Othmar

    ], [2]. Large-scale computations of electronic structure and dynamics pose extremely challenging powerful standard tools in electronic structure calculations of atoms and small molecules. Similar to DFT-dependent electronic Schr¨odinger equa- tion (TDSE) arising in ultrafast laser dynamics, which was first proposed in [1

  5. Free-energy functional of the electronic potential for Schrödinger-Poisson theory

    E-Print Network [OSTI]

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

    2014-12-15T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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); Rössler, E. A. [Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany)] [Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany)

    2013-12-28T23:59:59.000Z

    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 kHz–20 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 spin–nitrogen 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.

  7. Electron tomography of dislocation structures

    SciTech Connect (OSTI)

    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

    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.

  8. Perpendicular propagating electromagnetic envelope solitons in electron-positron-ion plasma

    SciTech Connect (OSTI)

    Jehan, Nusrat [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2010-05-15T23:59:59.000Z

    The nonlinear amplitude modulation of electromagnetic waves propagating perpendicular to the direction of ambient magnetic field in a uniform collisionless magnetized electron-positron-ion plasma is studied. The Krylov-Bogoliubov-Mitropolsky perturbation method is employed to derive nonlinear Schroedinger equation, which describes the amplitude dynamics of perturbed magnetic field. The modulation instability criterion reveals that the low frequency mode is always stable, whereas the high frequency mode becomes modulationally unstable for certain ranges of wave number and positron-to-electron density ratio. Furthermore, the positron-to-electron density ratio as well as the strength of ambient magnetic field is found to have significant effect on the solitary wave solutions of the nonlinear Schroedinger equation, namely, dark and bright envelope solitons.

  9. Can electron by Compton scattering be considered as a typical detector of the photon propagation

    E-Print Network [OSTI]

    Vladan Pankovic; Darko Kapor; Miodrag Krmar

    2010-06-11T23:59:59.000Z

    In this work we consider a possibility that Compton scattering can be considered as a typical measurement (detection) procedure within which electron behaves as the measuring apparatus, i.e. detector (pointer) of the propagation of the photon as the measured object. It represents a realistic variant of the old gendanken (though) experiment (discussed by Einstein, Bohr, Dirac, Feynman) of the interaction between the single photon as the measured object and a movable mirror as the measuring apparatus, i.e. detector (pointer). Here collapse by measurement is successfully modeled by spontaneous (non-dynamical) unitary symmetry (superposition) breaking (effective hiding) representing an especial case of the spontaneous (non-dynamical) breaking (effective hiding) of the dynamical symmetries. All this is full agreement with all existing experimental data and represents the definitive solution of the old problem of "micro" theoretical foundation of measurement or old problem of the foundation of quantum mechanics as a local (luminal) physical theory.

  10. Scalability of dynamic traffic assignment

    E-Print Network [OSTI]

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

    2009-01-01T23:59:59.000Z

    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 ...

  11. Solar Wind Electrons and Langmuir Turbulence , D.E. Larson

    E-Print Network [OSTI]

    California at Berkeley, University of

    electron VDFs contain high-energy tail [9] which is typically described as thermal core plus superthermal are in dynamical equilibrium with quasi-thermal noise turbulence. Customary theories of superthermal electrons

  12. Reduced electronic density matrices, effective Hamiltonians, and nonlinear susceptibilities of conjugated polyenes

    E-Print Network [OSTI]

    Mukamel, Shaul

    -acceptor substituted Hexatrienes demonstrate the interplay of electronic structure and dynamics, and the correlation the calculation of the optical response onto the dynam- ics of coupled electronic oscillators and suggests, which in turn controls the electronic dynamics. We further explore which characteristics of the ground

  13. Low energy 2+1 string gravity; black hole solutions

    E-Print Network [OSTI]

    A. A. Garcia Diaz; G. Gutierrez Cano

    2014-12-17T23:59:59.000Z

    In this report a detailed derivation of the dynamical equations for an n dimensional heterotic string theory of the Horowitz type is carried out in the string frame and in the Einstein frame too. In particular, the dynamical equations of the three dimensional string theory are explicitly given. The relation of the Horowitz Welch and Horne Horowitz string black hole solution is exhibited. The Chan Mann charged dilaton solution is derived and the subclass of string solutions field is explicitly identified. The stationary generalization, via SL(2;R) transformations, of the static (2+1) Horne Horowitz string black hole solution is given.

  14. Superthermal electron distribution measurements from polarized electron cyclotron emission

    SciTech Connect (OSTI)

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

    1988-06-01T23:59:59.000Z

    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.

  15. THz Dynamic Nuclear Polarization NMR

    E-Print Network [OSTI]

    Nanni, Emilio Alessandro

    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 ...

  16. A Birkhoff theorem for Shape Dynamics

    E-Print Network [OSTI]

    Henrique Gomes

    2014-04-02T23:59:59.000Z

    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.

  17. Oblique modulation of ion-acoustic waves and envelope solitons in electron-positron-ion plasma

    SciTech Connect (OSTI)

    Jehan, Nusrat [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2009-06-15T23:59:59.000Z

    The effect of oblique modulation on the amplitude dynamics of ion-acoustic wave propagating in a collisionless electron-positron-ion plasma is investigated. Using Krylov-Bogoliubov-Mitropolsky (KBM) perturbation method, a nonlinear Schroedinger (NLS) equation is derived which governs the evolution of obliquely modulated ion-acoustic envelope excitations. It is found that the presence of positron component significantly modifies the stability domains for small angles of propagation with the direction of modulation. The stationary solutions of NLS equation, i.e., bright and dark envelope solitons, become narrower as the concentration of positron component increases.

  18. Direct Observation of Optically Induced Transient Structures in Graphite Using Ultrafast Electron Crystallography

    E-Print Network [OSTI]

    initio density functional calculations, we trace the governing mechanism back to electronic structure changes in the electronic properties, direct de- termination of lattice structural dynamics from opticalDirect Observation of Optically Induced Transient Structures in Graphite Using Ultrafast Electron

  19. Dynamics of electromagnetic solitons in a relativistic plasma

    SciTech Connect (OSTI)

    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

    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.

  20. Solid-State Dynamic Nuclear Polarization at 263 GHz: Spectrometer Design and Experimental Results

    E-Print Network [OSTI]

    Rosay, Melanie

    Dynamic Nuclear Polarization (DNP) experiments transfer polarization from electron spins to nuclear spins with microwave irradiation of the electron spins for enhanced sensitivity in nuclear magnetic resonance (NMR) ...

  1. A Search for an Electron Antineutrino Signal

    E-Print Network [OSTI]

    Road, Ann Arbor, MI 48106-1346, to whom the author has granted "the right to reproduce and sell (a by any of the three product particles. Historically, proposals have suggested conversion of solar electron neutrinos into electron antineutrinos as either a solution to the "solar neutrino problem

  2. 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...

  3. Shape Dynamics. An Introduction

    E-Print Network [OSTI]

    Julian Barbour

    2011-05-01T23:59:59.000Z

    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.

  4. Dynamics of Bianchi type I elastic spacetimes

    E-Print Network [OSTI]

    Simone Calogero; J. Mark Heinzle

    2007-06-26T23:59:59.000Z

    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.

  5. Effects of partial charge-transfer solute -- solvent interactions in absorption spectra of aromatic hydrocarbons in aqueous and alcoholic solutions

    E-Print Network [OSTI]

    I. A. Ar'ev; N. I. Lebovka; E. A. Solovieva

    2013-03-03T23:59:59.000Z

    A method for study of charge-transfer interactions between solute molecules and solvent based on the comparison of the ratios of spectral shifts of different electronic transitions in solute molecules in chemically inert solvent is proposed. The method is applicable to molecules that do not change their dipole moment on excitation. As an example, a presence of charge transfer interactions in higher electronic states of aromatic hydrocarbons (benzene, phenanthrene, and naphthalene) dissolved in water and alcohols was demonstrated.

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

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

    2008-08-28T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Dumas, Jean-Guillaume

    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

  9. Natural geometric representation for electron local observables

    SciTech Connect (OSTI)

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

    2014-03-15T23:59:59.000Z

    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.

  10. Method of Linear Invariants for description of beam dynamics of FEL undulator

    E-Print Network [OSTI]

    A. Angelow; D. Trifonov; V. Angelov; H. Hristov

    2008-05-23T23:59:59.000Z

    We propose a new model for description of electrons beam dynamics in Free Electron Laser (FEL) undulator, based on the method of linear time-dependent invariants of quantum-mechanical charge particle. The magnetic field has periodic structure along the undulator. For this problem, described by time-dependent quadratic Hamiltonian, we obtain exact solution. The time-evolutions of the tree quantum fluctuations: covariance cov(q,p), var(q) and var(p) for the charge particle in this case are also determined. This research will help to optimize the FEL undulator: for example, using a 2.5 GeV linear electron accelerator it will be possible to emit radiation at 1.5 nm and shorter length. This method could be applicable also to any device with periodic structure of applied field (e.g. Tokamak, cyclic accelerators) for the case of charge non-relativistic quantum particles.

  11. Electron tube

    DOE Patents [OSTI]

    Suyama, Motohiro (Hamamatsu, JP); Fukasawa, Atsuhito (Hamamatsu, JP); Arisaka, Katsushi (Los Angeles, CA); Wang, Hanguo (North Hills, CA)

    2011-12-20T23:59:59.000Z

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  12. Electronic Systems for Radiation Detection in Space and High Energy Physics Applications

    E-Print Network [OSTI]

    Valerio, Pierpaolo; Ballabriga, Rafael

    This Ph.D. thesis focuses on the analysis and development of novel solution for electronics system for radiation detector, especially suited for space and high energy physics applications. The many blocks of a readout system were studied to develop complete systems, investigating where the performances can be improved over state of the art technologies. Two different architectures, suitable for different applications, were studied: Fractional Packet Counting, for High Dynamic Range (HDR) integrating imagers and CLICpix, an example of high-accuracy hybrid photon counting detector. The main specifications of the two systems were anayzed and solutions were proposed and implemented to meet them. A CLICpix prototype has been designed, fabricated using a commercial 65 nm CMOS technology and tested (characterization is still ongoing). The technology used for the prototype has also been characterized and validated for High Energy Physics (HEP) use and radiation hard design.

  13. Solution deposition assembly

    DOE Patents [OSTI]

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

    2014-01-21T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Voigt, James A. (Corrales, NM); Sipola, Diana L. (Albuquerque, NM); Tuttle, Bruce A. (Albuquerque, NM); Anderson, Mark T. (Woodbury, MN)

    1999-01-01T23:59:59.000Z

    A process 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.

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

    DOE Patents [OSTI]

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

    1999-06-01T23:59:59.000Z

    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.

  16. Solution to Quiz 5

    E-Print Network [OSTI]

    jeffb_000

    2013-12-02T23:59:59.000Z

    Nov 19, 2013 ... Calculate the total transaction costs incurred by Patrick and Eric combined. Solution: Ask Price = 30. Bid Ask Spread = 0.50 = Ask Price - Bid ...

  17. Mixed oxide solid solutions

    DOE Patents [OSTI]

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

    2003-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  19. Dispersant solutions for dispersing hydrocarbons

    DOE Patents [OSTI]

    Tyndall, Richard L. (Clinton, TN)

    1997-01-01T23:59:59.000Z

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

  20. Dispersant solutions for dispersing hydrocarbons

    DOE Patents [OSTI]

    Tyndall, R.L.

    1997-03-11T23:59:59.000Z

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

  1. Drama in Dynamics: Boom, Splash, and Speed

    SciTech Connect (OSTI)

    Heather Marie Netzloff

    2004-12-19T23:59:59.000Z

    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.

  2. Parallel and perpendicular velocity sheared flows driven tripolar vortices in an inhomogeneous electron-ion quantum magnetoplasma

    SciTech Connect (OSTI)

    Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Masood, W. [TPPD, PINSTECH, P.O. Nilore, Islamabad (Pakistan) and National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan)

    2011-12-15T23:59:59.000Z

    Nonlinear equations governing the dynamics of finite amplitude drift-ion acoustic-waves are derived by taking into account sheared ion flows parallel and perpendicular to the ambient magnetic field in a quantum magnetoplasma comprised of electrons and ions. It is shown that stationary solution of the nonlinear equations can be represented in the form of a tripolar vortex for specific profiles of the equilibrium sheared flows. The tripolar vortices are, however, observed to form on very short scales in dense quantum plasmas. The relevance of the present investigation with regard to dense astrophysical environments is also pointed out.

  3. Automatic Radar Antenna Scan Type Recognition in Electronic

    E-Print Network [OSTI]

    Barshan, Billur

    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

  4. Computing Partial Eigenvalue Sum in Electronic Structure Calculations

    E-Print Network [OSTI]

    Bai, Zhaojun

    and CPU time. In the application of electronic structure calculations in molecular dynamics, the newComputing Partial Eigenvalue Sum in Electronic Structure Calculations Z. Bai M. Faheyy G. Golubz M where computation of the total energy of an electronic structure requires the evaluation of partial

  5. The structure of electronic states in amorphous silicon

    E-Print Network [OSTI]

    Drabold, David

    the structure and dynamics of electron states in amorphous Si. The nature of the states near the gap at zeroThe structure of electronic states in amorphous silicon David A. Drabold,* Uwe Stephan, Jianjun for amorphous Si, which are of particular interest for efficient ab initio calculation of electronic properties

  6. A Simple Kinetic Model for Singlet Fission: A Role of Electronic and Entropic Contributions to Macroscopic Rates

    E-Print Network [OSTI]

    Krylov, Anna I.

    electronic structure calculations with the experimental observables. We aim at establishing a theoretical in molecular solids and model compounds. The electronic structure aspects of SF have received considerable quantities by modeling complicated nonadiabatic dynamics encompassing several interacting electronic states

  7. Bifurcations of traveling wave solutions for an integrable equation

    SciTech Connect (OSTI)

    Li Jibin [Department of Mathematics, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China) and Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Qiao Zhijun [Department of Mathematics, University of Texas Pan-American, 1201 West University Drive, Edinburg, Texas 78541 (United States)

    2010-04-15T23:59:59.000Z

    This paper deals with the following equation m{sub t}=(1/2)(1/m{sup k}){sub xxx}-(1/2)(1/m{sup k}){sub x}, which is proposed by Z. J. Qiao [J. Math. Phys. 48, 082701 (2007)] and Qiao and Liu [Chaos, Solitons Fractals 41, 587 (2009)]. By adopting the phase analysis method of planar dynamical systems and the theory of the singular traveling wave systems to the traveling wave solutions of the equation, it is shown that for different k, the equation may have infinitely many solitary wave solutions, periodic wave solutions, kink/antikink wave solutions, cusped solitary wave solutions, and breaking loop solutions. We discuss in a detail the cases of k=-2,-(1/2),(1/2),2, and parametric representations of all possible bounded traveling wave solutions are given in the different (c,g)-parameter regions.

  8. Electron transfer reactions in microporous solids

    SciTech Connect (OSTI)

    Mallouk, T.E.

    1992-05-01T23:59:59.000Z

    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.

  9. Chaotic Dynamics in Multidimensional Transition States Ali Allahem1, a)

    E-Print Network [OSTI]

    Chaotic Dynamics in Multidimensional Transition States Ali Allahem1, a) and Thomas Bartsch1, b consequences of normal hyperbolicity20,21 : a)Electronic mail: a.allahem@lboro.ac.uk b)Electronic mail: t.bartsch

  10. Solvent wash solution

    DOE Patents [OSTI]

    Neace, J.C.

    1984-03-13T23:59:59.000Z

    A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  11. Solvent wash solution

    DOE Patents [OSTI]

    Neace, James C. (Blackville, SC)

    1986-01-01T23:59:59.000Z

    Process for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 volume percent of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  12. [Inelastic electron scattering from surfaces]. [Progress report

    SciTech Connect (OSTI)

    Not Available

    1993-10-01T23:59:59.000Z

    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.

  13. Electron decay at IceCube

    E-Print Network [OSTI]

    Lynch, Morgan H

    2015-01-01T23:59:59.000Z

    In this paper we apply the formalism of Accelerated Quantum Dynamics (AQD) to the radiative stopping of highly relativistic electrons in ice. We compute the lifetime of electrons to decay into muons as well as the spectrum of the emitted muons. The energy of the emitted muon depends on the deceleration of the electron and this correlation can be used to tag the event and confirm the prediction. The results predict the acceleration-induced decay of electrons at IceCube energies. This experimental setting has the potential to establish the existence of the Unruh effect as well investigate the role of high acceleration in particle physics.

  14. Probing Ultrafast Solvation Dynamics with High Repetition-Rate...

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

    Ultrafast X-Ray Spectroscopy as a Probe of Nonequilibrium Dynamics in Ruthenium Complexes The Electronic Origin of Photoinduced Strain Modifying Proteins to Combat Disease Higher...

  15. 2013 R&D 100 Award: Movie-mode electron microscope captures nanoscale

    SciTech Connect (OSTI)

    Lagrange, Thomas; Reed, Bryan

    2014-04-03T23:59:59.000Z

    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.

  16. 2013 R&D 100 Award: Movie-mode electron microscope captures nanoscale

    ScienceCinema (OSTI)

    Lagrange, Thomas; Reed, Bryan

    2014-07-21T23:59:59.000Z

    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.

  17. ELECTRONIC WARFARE NOVEMBER 2012

    E-Print Network [OSTI]

    US Army Corps of Engineers

    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

  18. Integrating Security Solutions to Support nanoCMOS Electronics Research

    E-Print Network [OSTI]

    Sinnott, R.O.

    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.

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

    Office of Environmental Management (EM)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122Commercial602 1,39732onMakeEducation Programs BusinessRECORDS System (EDWS) |

  20. PIA - Savannah River Nuclear Solutions Electronic Safeguards Security

    Office of Environmental Management (EM)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122Commercial602 1,39732onMakeEducation Programs BusinessRECORDS SystemSystem (E3S) |

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

    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 onYouTube YouTube Note: Since the.pdfBreaking ofOilNEWResponse toOctoberMultifamily Landlords1Reality2009 |RECORDS System

  2. Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy

    E-Print Network [OSTI]

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

    2012-01-01T23:59:59.000Z

    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...

  3. Boltzmann-Electron Model in Aleph.

    SciTech Connect (OSTI)

    Hughes, Thomas Patrick; Hooper, Russell

    2014-11-01T23:59:59.000Z

    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

  4. Economic Viability of Dynamic Spectrum Management

    E-Print Network [OSTI]

    Huang, Jianwei

    providers, and government regulatory bodies. Providing proper economic incentives for everyone involved, proper economic incentives, and timely policy reforms. DSM is a promising solution to this issue. In DSMEconomic Viability of Dynamic Spectrum Management Jianwei Huang Network Communications

  5. Curvature Dependence of Hydrophobic Hydration Dynamics

    E-Print Network [OSTI]

    R. Gregor Weiß; Matthias Heyden; Joachim Dzubiella

    2015-04-08T23:59:59.000Z

    We investigate the curvature-dependence of water dynamics in the vicinity of hydrophobic spherical solutes using molecular dynamics simulations. For both, the lateral and perpendicular diffusivity as well as for H-bond kinetics of water in the first hydration shell, we find a non-monotonic solute-size dependence, exhibiting extrema close to the well-known structural crossover length scale for hydrophobic hydration. Additionally, we find an apparently anomalous diffusion for water moving parallel to the surface of small solutes, which, however, can be explained by topology effects. The intimate connection between solute curvature, water structure and dynamics has implications for our understanding of hydration dynamics at heterogeneous biomolecular surfaces.

  6. Beam Dynamics for ARIA

    E-Print Network [OSTI]

    Ekdahl, Carl

    2015-01-01T23:59:59.000Z

    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.

  7. Anatomy of bubbling solutions

    E-Print Network [OSTI]

    Kostas Skenderis; Marika Taylor

    2008-05-23T23:59:59.000Z

    We present a comprehensive analysis of holography for the bubbling solutions of Lin-Lunin-Maldacena. These solutions are uniquely determined by a coloring of a 2-plane, which was argued to correspond to the phase space of free fermions. We show that in general this phase space distribution does not determine fully the 1/2 BPS state of N=4 SYM that the gravitational solution is dual to, but it does determine it enough so that vevs of all single trace 1/2 BPS operators in that state are uniquely determined to leading order in the large N limit. These are precisely the vevs encoded in the asymptotics of the LLM solutions. We extract these vevs for operators up to dimension 4 using holographic renormalization and KK holography and show exact agreement with the field theory expressions.

  8. Quiz 5 Solutions

    E-Print Network [OSTI]

    Apr 25, 2015 ... Math 373. Spring 2015. Quiz 5. April 16, 2015. 1. In a short sale of a stock, there is credit risk. Define credit risk. Solution: Credit risk is the risk ...

  9. 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...

  10. Solution to Quiz 1

    E-Print Network [OSTI]

    jeffb_000

    2014-01-14T23:59:59.000Z

    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 ...

  11. Parallel Computer Technology -A Solution for Automobiles? How car engineers can learn from parallel computing

    E-Print Network [OSTI]

    Zachmann, Gabriel

    Parallel Computer Technology - A Solution for Automobiles? How car engineers can learn from be improved by the adoption of well known parallel computing technologies. II. HISTORY OF CAR ELECTRONICS electronics in the past. The following Table I shows the history of the car- electronics since 1950 in note

  12. Solutions of Penrose's Equation

    E-Print Network [OSTI]

    E. N. Glass; Jonathan Kress

    1998-09-27T23:59:59.000Z

    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.

  13. Manipulation of the distance of light-induced electron transfer within a semi-rigid donor(amine)/acceptor(terpyridine) assembly via

    E-Print Network [OSTI]

    structure calculations qualitatively reproduce the experimental observations. From the calculations interest in the kinetics and dynamics of electron transfer (ET) reac- tions, including reactions kinetics and dynamics studies: `how far is the electron transferred?' At first glance, this would appear

  14. Relativistic Remnants of Non-Relativistic Electrons

    E-Print Network [OSTI]

    Taro Kashiwa; Taisuke Yamaguchi

    2014-10-09T23:59:59.000Z

    Electrons obeying the Dirac equation are investigated under the non-relativistic $c \\mapsto \\infty$ limit. General solutions are given by derivatives of the relativistic invariant functions whose forms are different in the time- and the space-like region, yielding the delta function of $(ct)^2 - x^2$. This light-cone singularity does survive to show that the charge and the current density of electrons travel with the speed of light in spite of their massiveness.

  15. Mesoscale modeling of colloidal suspensions with adsorbing solutes

    E-Print Network [OSTI]

    Rei Tatsumi; Osamu Koike; Yukio Yamaguchi

    2015-01-14T23:59:59.000Z

    We construct a mesoscale model of colloidal suspensions that contain solutes reversibly adsorbing onto the colloidal particle surfaces. The present model describes the coupled dynamics of the colloidal particles, the host fluid, and the solutes through the Newton-Euler equations of motion, the hydrodynamic equations, and the advection-diffusion equation, respectively. The solute adsorption is modeled through a square-well potential, which represents a short-range attractive interaction between a particle and a solute molecule. The present model is formulated to be solved through direct numerical simulations. Some numerical results are presented to validate the simulations. The present model enables investigations of solute adsorption effects in the presence of a fluid flow and an inhomogeneous solute concentration distribution.

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

    SciTech Connect (OSTI)

    Stevens, B.

    1997-07-01T23:59:59.000Z

    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.

  17. Automated MAD and MIR structure solution

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berendzen, Joel [Biophysics Group, Mail Stop D454, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    1999-04-01T23:59:59.000Z

    A fully automated procedure for solving MIR and MAD structures has been developed using a scoring scheme to convert the structure-solution process into an optimization problem. Obtaining an electron-density map from X-ray diffraction data can be difficult and time-consuming even after the data have been collected, largely because MIR and MAD structure determinations currently require many subjective evaluations of the qualities of trial heavy-atom partial structures before a correct heavy-atom solution is obtained. A set of criteria for evaluating the quality of heavy-atom partial solutions in macromolecular crystallography have been developed. These have allowed the conversion of the crystal structure-solution process into an optimization problem and have allowed its automation. The SOLVE software has been used to solve MAD data sets with as many as 52 selenium sites in the asymmetric unit. The automated structure-solution process developed is a major step towards the fully automated structure-determination, model-building and refinement procedure which is needed for genomic scale structure determinations.

  18. Electronic Circuit Realization of the Logistic Map

    E-Print Network [OSTI]

    Madhekar Suneel

    2006-03-11T23:59:59.000Z

    An electronic circuit realization of the logistic difference equation is presented using analog electronics. The behavior of the realized system is evaluated against computer simulations of the same. The circuit is found to exhibit the entire range of dynamics of the logistic equation: fixed points, periodicity, period doubling, chaos and intermittency. Quantitative measurements of the dynamics of the realized system are presented and are found to be in good agreement with the theoretical values. Some possible applications of such a realization are briefly discussed.

  19. Elastic electron scattering from formic acid

    SciTech Connect (OSTI)

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

    2006-07-31T23:59:59.000Z

    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.

  20. Topics for GGAM Prelim A. Dynamical systems

    E-Print Network [OSTI]

    Hunter, John K.

    layer problems · Poincar´e-Lindstedt method for periodic solutions of ODEs · Method of multiple scales for oscillatory solutions of ODEs · WKB method References · For A and parts of C related to ODEs: S. H. Strogatz Oscillations, Dynamical Systems, and Bifurcations of Vector Fields; I. Stakgold, Green's Functions and Boundary

  1. Network structure and dynamics of hydrogenated amorphous silicon D.A. Drabold *, T.A. Abtew, F. Inam, Y. Pan

    E-Print Network [OSTI]

    Drabold, David

    upon reasonable calculations of the electron-lattice coupling and molecular dynamic simulationNetwork structure and dynamics of hydrogenated amorphous silicon D.A. Drabold *, T.A. Abtew, F on the network or lattice dynamics of the system, both in the electronic ground state and in an electronic

  2. Structural Fluctuations, Spin, Reorganization Energy, and Tunneling Energy Control of Intramolecular Electron Transfer

    E-Print Network [OSTI]

    Kurnikova, Maria

    calculations of electronic couplings, molecular dynamics simulations of molecular geometries, and Poisson exists to interpret electron-transfer (ET) reactions and their dependence upon molecular structure.1Structural Fluctuations, Spin, Reorganization Energy, and Tunneling Energy Control

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

    SciTech Connect (OSTI)

    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

    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.

  4. Development of electronic nose for measurement of agricultural odors 

    E-Print Network [OSTI]

    Bausch, Carrie Lynn

    2000-01-01T23:59:59.000Z

    , duration and offensiveness. An electronic nose can more accurately characterize an odor profile. The objectives of this project were to use components of swine manure and a solution that closely resembled the odor profile of swine manure to test...

  5. aladdin electron storage: Topics by E-print Network

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

    devices that maintain account balances) are the solution to electronic commerc... Bennet Yee; J. D. Tygar 1995-01-01 90 Object-based Storage CiteSeer Summary: We propose an I...

  6. Theoretical studies of electronically excited states

    SciTech Connect (OSTI)

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

    2014-10-06T23:59:59.000Z

    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.

  7. Fissile solution measurement apparatus

    DOE Patents [OSTI]

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

    1984-06-11T23:59:59.000Z

    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.

  8. Optically pulsed electron accelerator

    DOE Patents [OSTI]

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

    1985-05-20T23:59:59.000Z

    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.

  9. Optically pulsed electron accelerator

    DOE Patents [OSTI]

    Fraser, John S. (Los Alamos, NM); Sheffield, Richard L. (Los Alamos, NM)

    1987-01-01T23:59:59.000Z

    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 radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  10. Dynamical Spacetimes from Numerical Hydrodynamics

    E-Print Network [OSTI]

    Allan Adams; Nathan Benjamin; Arvin Moghaddam; Wojciech Musial

    2014-11-07T23:59:59.000Z

    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.

  11. Damping filter method for obtaining spatially localized solutions

    E-Print Network [OSTI]

    Toshiki Teramura; Sadayoshi Toh

    2014-04-30T23:59:59.000Z

    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.

  12. Offshore Renewable Energy Solutions

    E-Print Network [OSTI]

    and sustainable energy supply. The UK is uniquely placed to harness its natural resources ­ wind, wave and tidal 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

  13. 1.2 Solutions

    E-Print Network [OSTI]

    In other words, the graph of the ... coef?cient p0 — (k/r) of the exponential term in Eq. (19). 1f p0 > Mr ..... be other solutions, then perhaps we should continue to search for them. .... Then the tensile force in the rod does not enter the equation.

  14. Currents driven by electron cyclotron waves

    SciTech Connect (OSTI)

    Karney, C.F.F.; Fisch, N.J.

    1981-07-01T23:59:59.000Z

    Certain aspects of the generation of steady-state currents by electron cyclotron waves are explored. A numerical solution of the Fokker-Planck equation is used to verify the theory of Fisch and Boozer and to extend their results into the nonlinear regime. Relativistic effects on the current generated are discussed. Applications to steady-state tokamak reactors are considered.

  15. 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...

  16. Single Molecule Spectroscopy of Electron Transfer

    SciTech Connect (OSTI)

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

    2009-10-20T23:59:59.000Z

    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.

  17. Dynamics and instability of false vacuum bubbles

    E-Print Network [OSTI]

    Anthony Aguirre; Matthew C. Johnson

    2005-11-22T23:59:59.000Z

    This paper examines the classical dynamics of false vacuum regions embedded in surrounding regions of true vacuum, in the thin-wall limit. The dynamics of all generally relativistically allowed solutions -- most but not all of which have been previously studied -- are derived, enumerated, and interpreted. We comment on the relation of these solutions to possible mechanisms whereby inflating regions may be spawned from non-inflating ones. We then calculate the dynamics of first order deviations from spherical symmetry, finding that many solutions are unstable to such aspherical perturbations. The parameter space in which the perturbations on bound solutions inevitably become nonlinear is mapped. This instability has consequences for the Farhi-Guth-Guven mechanism for baby universe production via quantum tunneling.

  18. Dynamics and instability of false vacuum bubbles

    SciTech Connect (OSTI)

    Aguirre, Anthony; Johnson, Matthew C. [Department of Physics, University of California, Santa Cruz, California 95064 (United States)

    2005-11-15T23:59:59.000Z

    This paper examines the classical dynamics of false-vacuum regions embedded in surrounding regions of true vacuum, in the thin-wall limit. The dynamics of all generally relativistically allowed solutions--most but not all of which have been previously studied--are derived, enumerated, and interpreted. We comment on the relation of these solutions to possible mechanisms whereby inflating regions may be spawned from noninflating ones. We then calculate the dynamics of first-order deviations from spherical symmetry, finding that many solutions are unstable to such aspherical perturbations. The parameter space in which the perturbations on bound solutions inevitably become nonlinear is mapped. This instability has consequences for the Farhi-Guth-Guven mechanism for baby universe production via quantum tunneling.

  19. Structural Dynamics of a Catalytic Monolayer Probed by Ultrafast

    E-Print Network [OSTI]

    Fayer, Michael D.

    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

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

    E-Print Network [OSTI]

    Illing, Lucas

    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

  1. FREE-ELECTRON LASERS

    E-Print Network [OSTI]

    Sessler, A.M.

    2008-01-01T23:59:59.000Z

    Variable-Wiggler Free-Electron-Laser Oscillat.ion. Phys. :_.The Los Alamos Free Electron Laser: Accelerator Perfoemance.First Operation of a Free-Electron Laser. Phys . __ Rev~.

  2. FREE ELECTRON LASERS

    E-Print Network [OSTI]

    Colson, W.B.

    2008-01-01T23:59:59.000Z

    1984). Colson, W. B. , "Free electron laser theory," Ph.D.aspects of the free electron laser," Laser Handbook i,Quant. Elect. Bendor Free Electron Laser Conference, Journal

  3. Chapter 9: Electronics

    E-Print Network [OSTI]

    Spieler, Helmuth G

    2008-01-01T23:59:59.000Z

    R. Armstrong Contents Electronics 9.1 Introduction 9.2measurements 9.11 Digital electronics 9.11.1 Logic elementsProblems page 1 vii Electronics This chapter was contributed

  4. electronic reprint Acta Crystallographica Section B

    E-Print Network [OSTI]

    Vocadlo, Lidunka

    electronic reprint Acta Crystallographica Section B Structural Science ISSN 0108-7681 Structures, concluding that a CsCl-type structure would be the thermo- dynamically most stable phase for pressures calculations Lidunka Vocadlo, Geoffrey D. Price and I. G. Wood Copyright © International Union

  5. Stability of the electron cyclotron resonance

    E-Print Network [OSTI]

    Joachim Asch; Olivier Bourget; Cédric Meresse

    2014-12-30T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  7. Solution to the Proton Radius Problem

    E-Print Network [OSTI]

    D. Robson

    2015-01-27T23:59:59.000Z

    The relationship between the electric form factors for the proton in the rest frame and in the Breit momentum frame is used to provide a value for the difference in the mean squared charge radius of the proton evaluated in the two frames. Associating the muonic-hydrogen data analysis for the proton charge radius of 0.84087 fm with the rest frame and associating the electron scattering with the Breit frame yields a prediction 0f 0.87944 fm for the proton radius in the relativistic frame. The most recent value deduced via electron scattering from the proton is 0.877(6)fm so that the frame dependence used here yields a plausible solution to the proton radius puzzle.

  8. A continuum-atomistic method for incorporating Joule heating into classical molecular dynamics simulations

    E-Print Network [OSTI]

    Brenner, Donald W.

    binding electronic structure calculations, pertur- bation models, and quantum-classical Hamiltonians [6 depends on the degree of approximation used in solving the electronic structure problem, which can add-scale molecular dynamics (MD) simulation is not to model electron dynamics, but rather to numerically solve

  9. Shannon Entropy Based Time-Dependent Deterministic Sampling for Efficient "On-the-Fly" Quantum Dynamics

    E-Print Network [OSTI]

    Iyengar, Srinivasan S.

    Dynamics and Electronic Structure David Hocker, Xiaohu Li, and Srinivasan S. Iyengar* Department) approximates the electronic structure alongside the nuclei to simulate molecular dynamics. When AIMD techniques in electronic structure calculation. The approach is quantum-classical40,57-63 and involves the synergy between

  10. Computational Improvements to Quantum Wave Packet ab Initio Molecular Dynamics Using a Potential-Adapted,

    E-Print Network [OSTI]

    Iyengar, Srinivasan S.

    electronic structure calculations (at the level of density functional theory, Hartree-Fock, post- Hartree approach to treat the simultaneous dynamics of electrons and nuclei. The method is based on a synergy-H-Cl]- and [CH3-H-Cl]- along with simultaneous dynamical treatment of the electrons and classical nuclei, through

  11. Solution to Exam 1

    E-Print Network [OSTI]

    2012-02-07T23:59:59.000Z

    Page 1 .... Solution Letting what is under the square root be u, i.e., u = x3 + 2x2 + 1, we get du. 3x2 + 4x. = dx. Also remeber to ... about the city named Lafayette in Contra Costa County in California after t seconds from now (t = 0) .... (b) (6 points) Find the consumers' surplus at equilibrium (DON'T approximate the an- swer!).

  12. 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...

  13. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in...

  14. Electron Microscopy Center

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

    Electron Microscopy Center Argonne Home > EMC > EMC Home Electron Microscopy Center Web Site has moved This page has moved to http:www.anl.govcnmgroupelectron-microscopy-cente...

  15. 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 ...

  16. High-efficiency solution processable polymer photovoltaic cells by

    E-Print Network [OSTI]

    ,8 consisting of an interpenetrating network of electron donor and acceptor materials. This concept has alsoARTICLES High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends GANG LI1 , VISHAL SHROTRIYA1 , JINSONG HUANG1 , YAN YAO1 , TOM MORIARTY2 , KEITH EMERY2

  17. Electron Cloud Effects in Accelerators

    SciTech Connect (OSTI)

    Furman, M.A.

    2012-11-30T23:59:59.000Z

    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].

  18. A tale of coupled vibrations in solution told by coherent two-dimensional infrared spectroscopy

    E-Print Network [OSTI]

    Khalil, Munira, 1975-

    2004-01-01T23:59:59.000Z

    Coherent two-dimensional infrared (2D IR) spectroscopy is used as a tool for investigating the molecular structure and dynamics of coupled vibrations in solution on a picosecond timescale. The strongly coupled asymmetric ...

  19. Review: Greenhouse Solutions with Sustainable Energy

    E-Print Network [OSTI]

    Hamilton-Smith, Elery

    2009-01-01T23:59:59.000Z

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

  20. 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)

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

    2015-01-30T23:59:59.000Z

    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.

  1. 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)

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

    2015-01-30T23:59:59.000Z

    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 tomore »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.« less

  2. 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

  3. Bearwall Energy Efficient Solutions

    E-Print Network [OSTI]

    Sovero,M.

    2014-01-01T23:59:59.000Z

    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...

  4. Building America Solution Center

    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 DataDepartment of Energy Your Density Isn't Your Destiny: Theof Energy Future ofHydronic Heating inOctober 2011 | DepartmentSolution

  5. 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]

    Schubart, Christoph

    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

  6. Coherent control of plasma dynamics

    E-Print Network [OSTI]

    He, Z -H; Lebailly, V; Nees, J A; Krushelnick, K; Thomas, A G R

    2015-01-01T23:59:59.000Z

    Coherent control of a system involves steering an interaction to a final coherent state by controlling the phase of an applied field. Plasmas support coherent wave structures that can be generated by intense laser fields. Here, we demonstrate the coherent control of plasma dynamics in a laser wakefield electron acceleration experiment. A genetic algorithm is implemented using a deformable mirror with the electron beam signal as feedback, which allows a heuristic search for the optimal wavefront under laser-plasma conditions that is not known a priori. We are able to improve both the electron beam charge and angular distribution by an order of magnitude. These improvements do not simply correlate with having the `best' focal spot, since the highest quality vacuum focal spot produces a greatly inferior electron beam, but instead correspond to the particular laser phase that steers the plasma wave to a final state with optimal accelerating fields.

  7. Flow dynamics and solute transport in unsaturated rock fractures

    E-Print Network [OSTI]

    Su, G.W.

    2011-01-01T23:59:59.000Z

    channel only, while residual water from the initial invasionmeniscus coalesced with residual water along its flow pathto varying amounts of residual water left by the previous

  8. Flow dynamics and solute transport in unsaturated rock fractures

    SciTech Connect (OSTI)

    Su, G. W.

    1999-10-01T23:59:59.000Z

    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.

  9. 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 DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetterEconomy andTermsDepartment ofCummins Power

  10. 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 DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGENDDepartmentSeptember 2009 |Technology

  11. Sandia Energy - SCADA Engineering Solutions

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

    Engineering Solutions Home Stationary Power Safety, Security & Resilience of Energy Infrastructure Grid Modernization Cyber Security for Electric Infrastructure National...

  12. Future Electron-Hadron Colliders

    SciTech Connect (OSTI)

    Litvinenko, V.

    2010-05-23T23:59:59.000Z

    Outstanding research potential of electron-hadron colliders (EHC) was clearly demonstrated by first - and the only - electron-proton collider HERA (DESY, Germany). Physics data from HERA revealed new previously unknown facets of Quantum Chromo-Dynamics (QCD). EHC is an ultimate microscope probing QCD in its natural environment, i.e. inside the hadrons. In contrast with hadrons, electrons are elementary particles with known initial state. Hence, scattering electrons from hadrons provides a clearest pass to their secrets. It turns EHC into an ultimate machine for high precision QCD studies and opens access to rich physics with a great discovery potential: solving proton spin puzzle, observing gluon saturation or physics beyond standard model. Access to this physics requires high-energy high-luminosity EHCs and a wide reach in the center-of-mass (CM) energies. This paper gives a brief overview of four proposed electron-hadron colliders: ENC at GSI (Darmstadt, Germany), ELIC/MEIC at TJNAF (Newport News, VA, USA), eRHIC at BNL (Upton, NY, USA) and LHeC at CERN (Geneva, Switzerland). Future electron-hadron colliders promise to deliver very rich physics not only in the quantity but also in the precision. They are aiming at very high luminosity two-to-four orders of magnitude beyond the luminosity demonstrated by the very successful HERA. While ENC and LHeC are on opposite side of the energy spectrum, eRHIC and ELIC are competing for becoming an electron-ion collider (EIC) in the U.S. Administrations of BNL and Jlab, in concert with US DoE office of Nuclear Physics, work on the strategy for down-selecting between eRHIC and ELIC. The ENC, EIC and LHeC QCD physics programs to a large degree are complimentary to each other and to the LHC physics. In last decade, an Electron Ion Collider (EIC) collaboration held about 25 collaboration meetings to develop physics program for EIC with CM energy {approx}100 GeV. One of these meetings was held at GSI, where ENC topic was in the center of discussions. First dedicated LHeC workshop was held in 2008, with a number of dedicated workshops following it. Intense accelerator R&D program is needed to address the challenges posed by the EIC.

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

    SciTech Connect (OSTI)

    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

    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.

  14. CSR Fields: Direct Numerical Solution of the Maxwell___s Equation

    SciTech Connect (OSTI)

    Novokhatski, A.; /SLAC

    2011-06-22T23:59:59.000Z

    We discuss the properties of the coherent electromagnetic fields of a very short, ultra-relativistic bunch in a rectangular vacuum chamber inside a bending magnet. The analysis is based on the results of a direct numerical solution of Maxwell's equations together with Newton's equations. We use a new dispersion-free time-domain algorithm which employs a more efficient use of finite element mesh techniques and hence produces self-consistent and stable solutions for very short bunches. We investigate the fine structure of the CSR fields including coherent edge radiation. This approach should be useful in the study of existing and future concepts of particle accelerators and ultrafast coherent light sources. The coherent synchrotron radiation (CSR) fields have a strong action on the beam dynamics of very short bunches, which are moving in the bends of all kinds of magnetic elements. They are responsible for additional energy loss and energy spread; micro bunching and beam emittance growth. These fields may bound the efficiency of damping rings, electron-positron colliders and ultrafast coherent light sources, where high peak currents and very short bunches are envisioned. This is relevant to most high-brightness beam applications. On the other hand these fields together with transition radiation fields can be used for beam diagnostics or even as a powerful resource of THz radiation. A history of the study of CSR and a good collection of references can be found in [1]. Electromagnetic theory suggests several methods on how to calculate CSR fields. The most popular method is to use Lienard-Wiechert potentials. Other approach is to solve numerically the approximate equations, which are a Schrodinger type equation. These numerical methods are described in [2]. We suggest that a direct solution of Maxwell's equations together with Newton's equations can describe the detailed structure of the CSR fields [3].

  15. Ultrafast studies of organometallic photochemistry: The mechanism of carbon-hydrogen bond activation in solution

    SciTech Connect (OSTI)

    Bromberg, S.E.

    1998-05-01T23:59:59.000Z

    When certain organometallic compounds are photoexcited in room temperature alkane solution, they are able to break or activate the C-H bonds of the solvent. Understanding this potentially practical reaction requires a detailed knowledge of the entire reaction mechanism. Because of the dynamic nature of chemical reactions, time-resolved spectroscopy is commonly employed to follow the important events that take place as reactants are converted to products. For the organometallic reactions examined here, the electronic/structural characteristics of the chemical systems along with the time scales for the key steps in the reaction make ultrafast UV/Vis and IR spectroscopy along with nanosecond Step-Scan FTIR spectroscopy the ideal techniques to use for this study. An initial study of the photophysics of (non-activating) model metal carbonyls centering on the photodissociation of M(CO){sub 6} (M = Cr, W, Mo) was carried out in alkane solutions using ultrafast IR spectroscopy. Next, picosecond UV/vis studies of the C-H bond activation reaction of Cp{sup *}M(CO){sub 2} (M = Rh, Ir), conducted in room temperature alkane solution, are described in an effort to investigate the origin of the low quantum yield for bond cleavage ({approximately}1%). To monitor the chemistry that takes place in the reaction after CO is lost, a system with higher quantum yield is required. The reaction of Tp{sup *}Rh(CO){sub 2} (Tp{sup *} = HB-Pz{sub 3}{sup *}, Pz{sup *} = 3,5-dimethylpyrazolyl) in alkanes has a quantum yield of {approximately}30%, making time resolved spectroscopic measurements possible. From ultrafast IR experiments, two subsequently formed intermediates were observed. The nature of these intermediates are discussed and the first comprehensive reaction mechanism for a photochemical C-H activating organometallic complex is presented.

  16. ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE SOLAR WIND

    SciTech Connect (OSTI)

    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

    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.

  17. Exciton coherence lifetimes from electronic structure

    E-Print Network [OSTI]

    Parkhill, John; Aspuru-Guzik, Alan

    2011-01-01T23:59:59.000Z

    We model the coherent energy transfer of an electronic excitation within covalently linked aromatic homodimers from first-principles, to answer whether the usual models of the bath calculated via detailed electronic structure calculations can reproduce the key dynamics. For these systems the timescales of coherent transport are experimentally known from time-dependent polarization anisotropy measurements, and so we can directly assess the whether current techniques might be predictive for this phenomenon. Two choices of electronic basis states are investigated, and their relative merits discussed regarding the predictions of the perturbative model. The coupling of the electronic degrees of freedom to the nuclear degrees of freedom is calculated rather than assumed, and the fluorescence anisotropy decay is directly reproduced. Surprisingly we find that although TDDFT absolute energies are routinely in error by orders of magnitude more than the coupling energy, the coherent transport properties of these dimers ...

  18. Single Pass Electron Cooling Simulations for MEIC

    SciTech Connect (OSTI)

    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

    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.

  19. Statistics as a dynamical attractor

    E-Print Network [OSTI]

    Michail Zak

    2012-08-30T23:59:59.000Z

    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.

  20. Dynamics of Protein Hydration Water

    E-Print Network [OSTI]

    M. Wolf; S. Emmert; R. Gulich; P. Lunkenheimer; A. Loidl

    2014-12-08T23:59:59.000Z

    We present the frequency- and temperature-dependent dielectric properties of lysozyme solutions in a broad concentration regime, measured at subzero temperatures and compare the results with measurements above the freezing point of water and on hydrated lysozyme powder. Our experiments allow examining the dynamics of unfreezable hydration water in a broad temperature range including the so-called No Man's Land (160 - 235 K). The obtained results prove the bimodality of the hydration shell dynamics and are discussed in the context of the highly-debated fragile-to-strong transition of water.

  1. Semiclassical analysis of the electron-nuclear coupling in electronic non-adiabatic processes

    E-Print Network [OSTI]

    Agostini, Federica; Gross, E K U

    2015-01-01T23:59:59.000Z

    In the context of the exact factorization of the electron-nuclear wave function, the coupling between electrons and nuclei beyond the adiabatic regime is encoded (i) in the time-dependent vector and scalar potentials and (ii) in the electron-nuclear coupling operator. The former appear in the Schroedinger-like equation that drives the evolution of the nuclear degrees of freedom, whereas the latter is responsible for inducing non-adiabatic effects in the electronic evolution equation. As we have devoted previous studies to the analysis of the vector and scalar potentials, in this paper we focus on the properties of the electron-nuclear coupling operator, with the aim of describing a numerical procedure to approximate it within a semiclassical treatment of the nuclear dynamics.

  2. TheRate: Program for Ab Initio Direct Dynamics Calculations of Thermal and

    E-Print Network [OSTI]

    Truong, Thanh N.

    , and the convergence of the rate constants with respect to the number of electronic structure calculations. 1998 John is that such limited potential energy information may be obtained from accurate electronic structure calculations-- --Dynamics Calculations of Thermal and Vibrational

  3. Fiber coating with surfactant solutions Amy Q. Shen and Blake Gleason

    E-Print Network [OSTI]

    . Typically the coating is a thin layer of a liquid applied to a solid substrate in a dynamic manner different surfactant solutions. The classic film-coating problem dates back to early work of Landau, many important coating liq- uids are complex fluids consisting of surfactant solutions, mixed

  4. 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

  5. Decision-making in structure solution using Bayesian estimates of map quality: the PHENIX autosol wizard

    SciTech Connect (OSTI)

    Terwilliger, Thomas C [Los Alamos National Laboratory; Adams, Paul D [LBNL; Read, Randy J [UNIV OF CAMBRIDGE; Mccoy, Airlie J [UNIV OF CAMBRIDGE

    2008-01-01T23:59:59.000Z

    Ten measures of experimental electron-density-map quality are examined and the skewness of electron density is found to be the best indicator of actual map quality. A Bayesian approach to estimating map quality is developed and used in the PHENIX AutoSol wizard to make decisions during automated structure solution.

  6. Large-Scale First-Principles Molecular Dynamics simulations on the BlueGene/L Platform

    E-Print Network [OSTI]

    Franchetti, Franz

    . Keywords Electronic structure. Molecular Dynamics. Ab initio simulations. First-principles simulations of the electronic properties of the system. The electronic structure calculation is the most time-consuming part the past three decades to the development of efficient implementations of the electronic structure

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

    SciTech Connect (OSTI)

    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

    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.

  8. Harsh environments electronics : downhole applications.

    SciTech Connect (OSTI)

    Vianco, Paul Thomas

    2011-03-01T23:59:59.000Z

    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.

  9. Electron localization in solid acetonitrile.

    SciTech Connect (OSTI)

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

    2002-10-03T23:59:59.000Z

    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.

  10. Zeldovich flow on cosmic vacuum background new exact nonlinear analytical solution

    E-Print Network [OSTI]

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

    2001-01-01T23:59:59.000Z

    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.

  11. Free electron laser with bunched relativistic electron beam and electrostatic longitudinal wiggler

    SciTech Connect (OSTI)

    Sepehri Javan, Nasser [Department of Physics, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil (Iran, Islamic Republic of)

    2010-06-15T23:59:59.000Z

    The system of the nonlinear nonstationary equations describing spatial-temporal dynamics of the amplitudes of an undulator radiation and a space charge wave of a relativistic electron beam in the resonator is obtained. The electrostatic longitudinal wiggler is considered. A bunch of the electron beam injects to the resonator, at the ends of which two mirrors are placed. After the interaction of electrons of bunch with radiation in the presence of wiggler and after amplifying electromagnetic pulse, a part of radiation is reflected back by semitransparent mirror. Then, it reaches to the initial of the system where the other mirror is placed. Synchronously, when the pulse is reflecting, the other electron bunch enters to the resonator and interacts with the pulse. This operation has simulated until saturation of growth of the electromagnetic pulse. The dynamics of the problem is simulated by the method of macro particles. The dynamics of pulse amplification, motion of the electrons, and spectra of output radiation in each stage are simulated.

  12. Bump formation in the runaway electron tail

    E-Print Network [OSTI]

    Decker, J; Fülöp, T

    2015-01-01T23:59:59.000Z

    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...

  13. Introduction Linear Dynamics

    E-Print Network [OSTI]

    Zeghib, Abdelghani

    Introduction Results Linear Dynamics Lorentz Dynamics Actions of discrete groups on stationary Piccione) Geodeycos Meeting, Lyon, 28-30 April 2010 Abdelghani Zeghib Dynamics on Lorentz manifolds #12;Introduction Results Linear Dynamics Lorentz Dynamics Motivations and questions Examples 1 Introduction

  14. Carrier dynamics in Beryllium doped low-temperature-grown InGaAs/InAlAs

    SciTech Connect (OSTI)

    Globisch, B., E-mail: Bjoern.Globisch@hhi.fraunhofer.de; Dietz, R. J. B.; Stanze, D.; Göbel, T.; Schell, M. [Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin (Germany)

    2014-04-28T23:59:59.000Z

    The electron and hole dynamics in low-temperature-grown InGaAs/InAlAs multiple quantum well structures are studied by optical pump-probe transmission measurements for Beryllium (Be) doping levels between 3?×?10{sup 17}?cm{sup ?3} and 4?×?10{sup 18}?cm{sup ?3}. We investigate electron dynamics in the limit cases of unsaturated and completely saturated electron trapping. By expanding a rate equation model in these limits, the details of carrier dynamics are revealed. Electrons are trapped by ionized arsenic antisites, whereas recombination occurs between trapped electrons and holes trapped by negatively charged Be dopants.

  15. Coherent Terahertz Polarization Control through Manipulation of Electron Trajectories Haidan Wen1

    E-Print Network [OSTI]

    Coherent Terahertz Polarization Control through Manipulation of Electron Trajectories Haidan Wen1 for manipulating and controlling the electron dy- namics associated with nonlinear light-matter interactions) The dynamics of ionized electrons in a plasma can be controlled by synthetic optical fields composed

  16. 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

  17. PetaScale Calculations of the Electronic Structures of Nanostructures with Hundreds of Thousands of Processors

    E-Print Network [OSTI]

    PetaScale Calculations of the Electronic Structures of Nanostructures with Hundreds of Thousands in the material science category. The DFT can be used to calculate the electronic structure, the charge density. To understand the electronic structures of such systems and the corresponding carrier dynamics is essential

  18. Ultraviolet Spectroscopy of Protein Backbone Transitions in Aqueous Solution: Combined QM and MM Simulations

    E-Print Network [OSTI]

    Mukamel, Shaul

    -level electronic structure calculations of N-methylacetamide (NMA). Its electrostatic fluctuations are modeled forcefield and electronic structures of sampled MD snapshots calculated by QM. The lineshapes and excitation depends crucially on their secondary structure and dynamic fluctuations.1 Optical spec- troscopy provides

  19. Interaction effects on dynamical localization in driven helium

    E-Print Network [OSTI]

    Felix Jörder; Klaus Zimmermann; Alberto Rodriguez; Andreas Buchleitner

    2014-08-22T23:59:59.000Z

    Dynamical localization prevents driven atomic systems from fast fragmentation by hampering the excitation process. We present numerical simulations within a collinear model of microwave-driven helium Rydberg atoms and prove that dynamical localization survives the impact of electron-electron interaction, even for doubly excited states in the presence of fast autoionization. We conclude that the effect of electron-electron repulsion on localization can be described by an appropriate rescaling of the atomic level density and of the external field with the strength of the interaction.

  20. Catalac free electron laser

    DOE Patents [OSTI]

    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

    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.

  1. Matter & Energy Electronics

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    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

  2. Magnetic turbulent electron transport in a reversed field pinch

    SciTech Connect (OSTI)

    Schoenberg, K.; Moses, R.

    1990-01-01T23:59:59.000Z

    A model of magnetic turbulent electron transport is presented. The model, based on the thermal conduction theory of Rechester and Rosenbluth, entails a Boltzmann description of electron dynamics in the long mean-free-path limit and quantitatively describes the salient features of superthermal electron measurements in the RFP edge plasma. Included are predictions of the mean superthermal electron energy, current density, and power flux asymmetry. A discussion of the transport model, the assumptions implicit in the model, and the relevance of this work to more general issue of magnetic turbulent transport in toroidal systems is presented. 32 refs., 3 figs.

  3. Achromatic and Isochronous Electron Beam Transport for Free Electron Lasers

    E-Print Network [OSTI]

    Bengtsson, J.

    2011-01-01T23:59:59.000Z

    Beamlines for Free Electron Lasers," LBL-28880 Preprint (Thirteenth mtemational Free Electron Laser Conference, SantaTransport for Tunable Free Electron Lasers 1. Bengtsson and

  4. 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...

  5. Neutrinos in the Electron

    E-Print Network [OSTI]

    E. L. Koschmieder

    2006-09-26T23:59:59.000Z

    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.

  6. Approximate Dynamic Programming for a Class of Long-Horizon ...

    E-Print Network [OSTI]

    2014-04-06T23:59:59.000Z

    require hours to produce good solutions even when the planning horizon is 90 ... Surveys of general IRPs for all modes of transportation are given in [1] and [9]. .... Dynamic fleet management problems are a special case in this problem class.

  7. Electron-Vibron Coupling at Metal-Organic Interfaces

    E-Print Network [OSTI]

    Rosenow, Phil; Tonner, Ralf

    2015-01-01T23:59:59.000Z

    We study the significance and characteristics of interfacial dynamical charge transfer at metal-organic interfaces for the model system of organic semiconductor NTCDA on Ag(111). We combine infrared absorption spectroscopy and dispersion-corrected density functional theory calculations to analyze dynamic dipole moments and electron-vibron coupling at the interface. We demonstrate that interfacial dynamical charge transfer is the dominant cause of infrared activity in these systems and that it correlates with results from partial charge and density of states analysis. Nuclear motion generates an additional dynamic dipole moment but represents a minor effect except for modes with significant out-of-plane amplitudes.

  8. "Dark energy" as conformal dynamics of space

    E-Print Network [OSTI]

    D. Burlankov

    2006-10-23T23:59:59.000Z

    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.

  9. Dark Energy and Electrons

    E-Print Network [OSTI]

    Burra G. Sidharth

    2008-08-05T23:59:59.000Z

    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.

  10. 2+1 dimensional solution of Einstein Cartan equations

    E-Print Network [OSTI]

    M. Hortacsu; H. T. Ozcelik; N. Ozdemir

    2008-07-28T23:59:59.000Z

    In this work a static solution of Einstein-Cartan (EC) equations in 2+1 dimensional space-time is given by considering classical spin-1/2 field as external source for torsion of the space-time. Here, the torsion tensor is obtained from metricity condition for the connection and the static spinor field is determined as the solution of Dirac equation in 2+1 spacetime with non-zero cosmological constant and torsion. The torsion itself is considered as a non-dynamical field.

  11. On isotropic metric of Schwarzschild solution of Einstein equation

    E-Print Network [OSTI]

    T. Mei

    2006-10-24T23:59:59.000Z

    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

  12. Is Nuclear Energy the Solution?

    E-Print Network [OSTI]

    Saier, Milton H.; Trevors, Jack T.

    2010-01-01T23:59:59.000Z

    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)

  13. Enhanced safeguards via solution monitoring

    SciTech Connect (OSTI)

    Burr, T.; Wangen, L.

    1996-09-01T23:59:59.000Z

    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.

  14. Frontiers of in situ electron microscopy

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

    Zheng, Haimei; Zhu, Yimei; Meng, Shirley Ying

    2015-01-01T23:59:59.000Z

    In situ transmission electron microscopy (TEM) has become an increasingly important tool for materials characterization. It provides key information on the structural dynamics of a material during transformations and the correlation between structure and properties of materials. With the recent advances in instrumentation, including aberration corrected optics, sample environment control, the sample stage, and fast and sensitive data acquisition, in situ TEM characterization has become more and more powerful. In this article, a brief review of the current status and future opportunities of in situ TEM is included. It also provides an introduction to the six articles covered by inmore »this issue of MRS Bulletin explore the frontiers of in situ electron microscopy, including liquid and gas environmental TEM, dynamic four-dimensional TEM, nanomechanics, ferroelectric domain switching studied by in situ TEM, and state-of-the-art atomic imaging of light elements (i.e., carbon atoms) and individual defects.« less

  15. High conductivity electrolyte solutions and rechargeable cells incorporating such solutions

    DOE Patents [OSTI]

    Angell, C.A.; Zhang, S.S.; Xu, K.

    1998-10-20T23:59:59.000Z

    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.

  16. Dynamics of empty homogeneous isotropic three-dimensional spaces

    E-Print Network [OSTI]

    A. V. Klimenko; V. A. Klimenko

    2012-02-28T23:59:59.000Z

    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.

  17. Modal aerosol dynamics modeling

    SciTech Connect (OSTI)

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

    1991-02-01T23:59:59.000Z

    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.

  18. JLAB Electron Driver Capabilities

    SciTech Connect (OSTI)

    Kazimi, Reza [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

    2009-09-02T23:59:59.000Z

    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.

  19. Separated spin-up and spin-down quantum hydrodynamics of degenerated electrons: spin-electron acoustic wave appearance

    E-Print Network [OSTI]

    Pavel A. Andreev

    2014-05-04T23:59:59.000Z

    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.

  20. Chaos in free electron laser oscillators

    E-Print Network [OSTI]

    C. Bruni; R. Bachelard; D. Garzella; G. L. Orlandi; M. E. Couprie

    2009-09-04T23:59:59.000Z

    The chaotic nature of a storage-ring Free Electron Laser (FEL) is investigated. The derivation of a low embedding dimension for the dynamics allows the low-dimensionality of this complex system to be observed, whereas its unpredictability is demonstrated, in some ranges of parameters, by a positive Lyapounov exponent. The route to chaos is then explored by tuning a single control parameter, and a period-doubling cascade is evidenced, as well as intermittence.