National Library of Energy BETA

Sample records for friso van der

  1. S.Van der Meer tribute

    ScienceCinema (OSTI)

    None

    2011-04-25

    Plusieurs intervenants rendent hommage à Simon Van der Meer né en 1925 à La Haye NL et prix nobel de physique en 1984

  2. Molecular adsorption on metal surfaces with van der Waals density...

    Office of Scientific and Technical Information (OSTI)

    Molecular adsorption on metal surfaces with van der Waals density functionals Title: Molecular adsorption on metal surfaces with van der Waals density functionals Authors: Li, Guo ...

  3. Van der Waals metal-semiconductor junction: Weak Fermi level...

    Office of Scientific and Technical Information (OSTI)

    Van der Waals metal-semiconductor junction: Weak Fermi level pinning enables effective tuning of Schottky barrier Citation Details In-Document Search Title: Van der Waals ...

  4. Direct observation of adsorption geometry for the van der Waals...

    Office of Scientific and Technical Information (OSTI)

    Weak van der Waals adsorption of -conjugated hydrocarbon molecules onto the gold surface, Au(111), is one of the essential processes in constructing organic-metal interfaces in ...

  5. Isotope separation by photodissociation of Van der Waal's molecules

    DOE Patents [OSTI]

    Lee, Yuan T.

    1977-01-01

    A method of separating isotopes based on the dissociation of a Van der Waal's complex. A beam of molecules of a Van der Waal's complex containing, as one partner of the complex, a molecular species in which an element is present in a plurality of isotopes is subjected to radiation from a source tuned to a frequency which will selectively excite vibrational motion by a vibrational transition or through electronic transition of those complexed molecules of the molecular species which contain a desired isotope. Since the Van der Waal's binding energy is much smaller than the excitational energy of vibrational motion, the thus excited Van der Waal's complex dissociate into molecular components enriched in the desired isotope. The recoil velocity associated with vibrational to translational and rotational relaxation will send the separated molecules away from the beam whereupon the product enriched in the desired isotope can be separated from the constituents of the beam.

  6. DOE - Office of Legacy Management -- Purdue University Van Der Graaf

    Office of Legacy Management (LM)

    Laboratory - IN 02 Purdue University Van Der Graaf Laboratory - IN 02 FUSRAP Considered Sites Site: PURDUE UNIVERSITY VAN DER GRAAF LABORATORY (IN.02) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Lafayette , Indiana IN.02-1 Evaluation Year: 1987 IN.02-3 Site Operations: Conducted research and development operations involving small quantities of radioactive material. IN.02-3 Site Disposition: Eliminated - NRC licensed -

  7. (Physics and chemistry of van der Waals particles)

    SciTech Connect (OSTI)

    Klots, C.E.

    1990-10-08

    Accounts are given of the two major international conferences on the physics and chemistry of small particles, commonly referred to as van der Waals particles. Details of special interest to Oak Ridge National Laboratory personnel are cited. Information exchanges at Freiburg and Paris are described.

  8. Excited nucleon as a van der Waals system of partons

    SciTech Connect (OSTI)

    Jenkovszky, L. L.; Muskeyev, A. O. Yezhov, S. N.

    2012-06-15

    Saturation in deep inelastic scattering (DIS) and deeply virtual Compton scattering (DVCS) is associated with a phase transition between the partonic gas, typical of moderate x and Q{sup 2}, and partonic fluid appearing at increasing Q{sup 2} and decreasing Bjorken x. We suggest the van der Waals equation of state to describe properly this phase transition.

  9. Structure and dynamics of small van der Waals complexes

    SciTech Connect (OSTI)

    Loreau, J.

    2014-10-06

    We illustrate computational aspects of the calculation of the potential energy surfaces of small (up to five atoms) van der Waals complexes with high-level quantum chemistry techniques such as the CCSD(T) method with extended basis sets. We discuss the compromise between the required accuracy and the computational time. Further, we show how these potential energy surfaces can be fitted and used in dynamical calculations such as non-reactive inelastic scattering.

  10. Application of Diffusion Monte Carlo to Materials Dominated by van der Waals Interactions

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

    Benali, Anouar; Shulenburger, Luke; Romero, Nichols A.; Kim, Jeongnim; von Lilienfeld, O. Anatole

    2014-06-12

    Van der Waals forces are notoriously difficult to account for from first principles. We perform extensive calculation to assess the usefulness and validity of diffusion quantum Monte Carlo when applied to van der Waals forces. We present results for noble gas solids and clusters - archetypical van der Waals dominated assemblies, as well as a relevant pi-pi stacking supramolecular complex: DNA + intercalating anti-cancer drug Ellipticine.

  11. Heterostructures based on inorganic and organic van der Waals systems

    SciTech Connect (OSTI)

    Lee, Gwan-Hyoung; Lee, Chul-Ho; Zande, Arend M. van der; Han, Minyong; Cui, Xu; Arefe, Ghidewon; Hone, James; Nuckolls, Colin; Heinz, Tony F.; Kim, Philip

    2014-09-01

    The two-dimensional limit of layered materials has recently been realized through the use of van der Waals (vdW) heterostructures composed of weakly interacting layers. In this paper, we describe two different classes of vdW heterostructures: inorganic vdW heterostructures prepared by co-lamination and restacking; and organic-inorganic hetero-epitaxy created by physical vapor deposition of organic molecule crystals on an inorganic vdW substrate. Both types of heterostructures exhibit atomically clean vdW interfaces. Employing such vdW heterostructures, we have demonstrated various novel devices, including graphene/hexagonal boron nitride (hBN) and MoS{sub 2} heterostructures for memory devices; graphene/MoS{sub 2}/WSe{sub 2}/graphene vertical p-n junctions for photovoltaic devices, and organic crystals on hBN with graphene electrodes for high-performance transistors.

  12. A crossover in anisotropic nanomechanochemistry of van der Waals crystals

    SciTech Connect (OSTI)

    Shimamura, Kohei; Misawa, Masaaki; Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya; Shimojo, Fuyuki

    2015-12-07

    In nanoscale mechanochemistry, mechanical forces selectively break covalent bonds to essentially control chemical reactions. An archetype is anisotropic detonation of layered energetic molecular crystals bonded by van der Waals (vdW) interactions. Here, quantum molecular dynamics simulations reveal a crossover of anisotropic nanomechanochemistry of vdW crystal. Within 10{sup −13} s from the passage of shock front, lateral collision produces NO{sub 2} via twisting and bending of nitro-groups and the resulting inverse Jahn-Teller effect, which is mediated by strong intra-layer hydrogen bonds. Subsequently, as we transition from heterogeneous to homogeneous mechanochemical regimes around 10{sup −12} s, shock normal to multilayers becomes more reactive, producing H{sub 2}O assisted by inter-layer N-N bond formation. These time-resolved results provide much needed atomistic understanding of nanomechanochemistry that underlies a wider range of technologies.

  13. Graphene on boron-nitride: Moir pattern in the van der Waals energy

    SciTech Connect (OSTI)

    Neek-Amal, M. [Department of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Department of Physics, Shahid Rajaee University, Lavizan, Tehran 16788 (Iran, Islamic Republic of); Peeters, F. M. [Department of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)

    2014-01-27

    The spatial dependence of the van der Waals (vdW) energy between graphene and hexagonal boron-nitride (h-BN) is investigated using atomistic simulations. The van der Waals energy between graphene and h-BN shows a hexagonal superlattice structure identical to the observed Moir pattern in the local density of states, which depends on the lattice mismatch and misorientation angle between graphene and h-BN. Our results provide atomistic features of the weak van der Waals interaction between graphene and BN which are in agreement with experiment and provide an analytical expression for the size of the spatial variation of the weak van der Waals interaction. We also found that the A-B-lattice symmetry of graphene is broken along the armchair direction.

  14. Spin-Flavor van der Waals Forces and NN interaction (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Spin-Flavor van der Waals Forces and NN interaction A major goal in Nuclear Physics ... Because of this the resulting nuclear forces at sufficiently large distances correspond to ...

  15. Nano-photonic phenomena in van der Waals heterostructures | MIT-Harvard

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

    Center for Excitonics Nano-photonic phenomena in van der Waals heterostructures March 31, 2015 at 4:30 PM/ RLE Haus 36-428 Dmitri Basov Department of Physics, University of California, San Diego Dimitri_basov_01 abstract: Layered van der Waals (vdW) crystals consist of individual atomic planes weakly coupled by vdW interaction, similar to graphene monolayers in bulk graphite. These materials can harbor superconductivity and ferromagnetism with high transition temperatures, emit light and

  16. Structural and Vibrational Properties of Liquid Water from van der Waals

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

    Density Functionals | Argonne Leadership Computing Facility Structural and Vibrational Properties of Liquid Water from van der Waals Density Functionals Authors: Zhang, C., Wu, J., Gygi, F., Galli, G. We present results for the structural and vibrational properties of the water molecule, water dimer, and liquid water at the experimental equilibrium density, as obtained with several van der Waals density functionals. The functional form originally proposed by Dion et al. [ Phys. Rev. Lett.

  17. The role of collective motion in the ultrafast charge transfer in van der Waals heterostructures

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

    Wang, Han; Bang, Junhyeok; Sun, Yiyang; West, Damien; Meunier, Vincent; Zhang, Shengbai; Liang, Linagbo

    2016-05-10

    Here, the success of van der Waals (vdW) heterostructures, made of graphene, metal dichalcogenides, and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that vdW heterostructues can exhibit ultra-fast charge transfer despite the weak binding of the heterostructure. Using time-dependent density functional theory molecular dynamics, we identify a strong dynamic coupling between the vdW layers associated with charge transfer. This dynamic coupling results in rapid nonlinear coherentmore » charge oscillations which constitute a purely electronic phenomenon and are shown to be a general feature of vdW heterostructures provided they have a critical minimum dipole coupling. Application to MoS2/WS2 heterostructure yields good agreement with experiment, indicating near complete charge transfer within a timescale of 100 fs.The success of van der Waals heterostructures made of graphene, metal dichalcogenides and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that van der Waals heterostructues can exhibit ultrafast charge transfer despite the weak binding of these heterostructures. Here we find, using time-dependent density functional theory molecular dynamics, that the collective motion of excitons at the interface leads to plasma oscillations associated with optical excitation. By constructing a simple model of the van der Waals heterostructure, we show that there exists an unexpected criticality of the oscillations, yielding rapid charge transfer across the

  18. Scientific Advisory Committee

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

    (ALS), Peter Abbamonte, Nora Berrah, David Osborn, George Crabtree, Steve Kevan, Peter Johnson, Keith Moffat, Lou Terminello, Chris Jacobson, Sam Krinsky, Friso van der Veen,...

  19. Scientific Advisory Committee

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

    Roger Falcone, Corie Ralston, George Crabtree, Keith Moffat, Friso van der Veen, Maya Kiskinova, and Robert Hettel. Not pictured: Kathy Yelick, Jean Susini, and Robert...

  20. Scientific Advisory Committee

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

    George Crabtree, Steve Kevan, Peter Johnson, Keith Moffat, Lou Terminello, Chris Jacobson, Sam Krinsky, Friso van der Veen, Maya Kiskinova, and Ben Feinberg (ALS). Not...

  1. Quantum chaos of the hydrogen atom in a generalized van der Waals potential

    SciTech Connect (OSTI)

    Ganesan, K.; Lakshmanan, M. (Centre for Nonlinear Dynamics, Department of Physics, Bharathidasan University, Tiruchirapalli-620024, Tamilnadu (India))

    1993-08-01

    The quantum manifestations of chaos in the hydrogen atom in a generalized van der Waals potential, which includes the celebrated quadratic-Zeeman-effect problem under an appropriate limiting condition, are studied in detail. Using group-theoretical methods, we derive the matrix elements in an algebraic form. As the Hamiltonian is scale invariant, we introduce an appropriate scaling parameter. By considering the unperturbed hydrogen-atom problem, we demonstrate that suitable changes in the scaling parameter stabilize different parts of the spectrum depending upon the parameter's value. For the present generalized van der Waals potential problem, we utilize this property of the scaling parameter effectively to improve the convergence of eigenvalues while diagonalizing the matrices for various parametric values. Then, we vary one of the system parameters in the range [0,3], study the level statistics, and observe a GOE-Poisson-Brody-Poisson-Brody-Poisson-GOE-type (where GOE means Gaussian orthogonal ensemble) of transition regime hitherto unidentified in any of the perturbed hydrogen-atom problems. Our results are not only in agreement with random-matrix-theory predictions but also justify classical and semiclassical investigations.

  2. Binding and Diffusion of Lithium in Graphite: Quantum Monte Carlo Benchmarks and Validation of van der Waals Density Functional Methods

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

    Ganesh, P.; Kim, Jeongnim; Park, Changwon; Yoon, Mina; Reboredo, Fernando A.; Kent, Paul R. C.

    2014-11-03

    In highly accurate diffusion quantum Monte Carlo (QMC) studies of the adsorption and diffusion of atomic lithium in AA-stacked graphite are compared with van der Waals-including density functional theory (DFT) calculations. Predicted QMC lattice constants for pure AA graphite agree with experiment. Pure AA-stacked graphite is shown to challenge many van der Waals methods even when they are accurate for conventional AB graphite. Moreover, the highest overall DFT accuracy, considering pure AA-stacked graphite as well as lithium binding and diffusion, is obtained by the self-consistent van der Waals functional vdW-DF2, although errors in binding energies remain. Empirical approaches based onmore » point charges such as DFT-D are inaccurate unless the local charge transfer is assessed. Our results demonstrate that the lithium carbon system requires a simultaneous highly accurate description of both charge transfer and van der Waals interactions, favoring self-consistent approaches.« less

  3. Phase diagram of Rydberg atoms with repulsive van der Waals interaction

    SciTech Connect (OSTI)

    Osychenko, O. N.; Astrakharchik, G. E.; Boronat, J.; Lutsyshyn, Y.; Lozovik, Yu. E.

    2011-12-15

    We report a quantum Monte Carlo calculation of the phase diagram of bosons interacting with a repulsive inverse sixth power pair potential, a model for assemblies of Rydberg atoms in the local van der Waals blockade regime. The model can be parametrized in terms of just two parameters, the reduced density and temperature. Solidification happens to the fcc phase. At zero temperature, the transition density is found with the diffusion Monte Carlo method at density {rho}=3.9 (({Dirac_h}/2{pi}){sup 2}/mC{sub 6}){sup 3/4}, where C{sub 6} is the strength of the interaction. The solidification curve at nonzero temperature is studied with the path-integral Monte Carlo approach and is compared with transitions in corresponding harmonic and classical crystals. Relaxation mechanisms are considered in relation to present experiments.

  4. van der Waals forces in density functional theory: a review of the vdW-DF method

    SciTech Connect (OSTI)

    Berland, Kristian; Cooper, Valentino R.; Lee, Kyuho; Schröder, Elsebeth; Thonhauser, T.; Hyldgaard, Per; Lundqvist, Bengt I.

    2015-05-15

    We review a density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology. The insights that led to the construction of the Rutgers–Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only for dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.

  5. van der Waals forces in density functional theory: a review of the vdW-DF method

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

    Berland, Kristian; Cooper, Valentino R.; Lee, Kyuho; Schröder, Elsebeth; Thonhauser, T.; Hyldgaard, Per; Lundqvist, Bengt I.

    2015-05-15

    We review a density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology. The insights that led to the construction of the Rutgers–Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only formore » dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.« less

  6. Temperature dependent van der Pauw-Hall measurements on sodium doped single crystalline cadmium telluride

    SciTech Connect (OSTI)

    Ahmad, Faisal R.

    2015-03-21

    In this report, results of the temperature dependent electrical conductivity measurements conducted on single crystalline cadmium telluride (CdTe), containing sodium (Na) impurities are presented and discussed. The electrical conductivity measurements were conducted using an apparatus that allowed the implementation of a standard van der Pauw-Hall effect technique through which the electrical resistivity, concentration of majority carriers, as well as the carrier mobility were determined for temperatures ranging between 24 K and 350 K. Over this temperature range, the electrical resistivity was observed to change by 7 orders of magnitude. Hall measurements showed that the hole concentration at 300 K was ∼3 × 10{sup 15 }cm{sup –3} and the hole mobility at the same temperature was ∼80 cm{sup 2}/V s. Measuring the concentration of holes as a function of the sample temperature enabled the estimation of the acceptor energy level with respect to the valence band maximum to be ∼60 meV. The same data also revealed the potential presence of a compensating donor level. Furthermore, the hole mobility was also analyzed over the entire temperature range and the data revealed that above 100 K, the carrier mobility was dominated by the scattering of holes from lattice vibrations.

  7. Turbulent mixing of a slightly supercritical van der Waals fluid at low-Mach number

    SciTech Connect (OSTI)

    Battista, F.; Casciola, C. M.; Picano, F.

    2014-05-15

    Supercritical fluids near the critical point are characterized by liquid-like densities and gas-like transport properties. These features are purposely exploited in different contexts ranging from natural products extraction/fractionation to aerospace propulsion. Large part of studies concerns this last context, focusing on the dynamics of supercritical fluids at high Mach number where compressibility and thermodynamics strictly interact. Despite the widespread use also at low Mach number, the turbulent mixing properties of slightly supercritical fluids have still not investigated in detail in this regime. This topic is addressed here by dealing with Direct Numerical Simulations of a coaxial jet of a slightly supercritical van der Waals fluid. Since acoustic effects are irrelevant in the low Mach number conditions found in many industrial applications, the numerical model is based on a suitable low-Mach number expansion of the governing equation. According to experimental observations, the weakly supercritical regime is characterized by the formation of finger-like structures the so-called ligaments in the shear layers separating the two streams. The mechanism of ligament formation at vanishing Mach number is extracted from the simulations and a detailed statistical characterization is provided. Ligaments always form whenever a high density contrast occurs, independently of real or perfect gas behaviors. The difference between real and perfect gas conditions is found in the ligament small-scale structure. More intense density gradients and thinner interfaces characterize the near critical fluid in comparison with the smoother behavior of the perfect gas. A phenomenological interpretation is here provided on the basis of the real gas thermodynamics properties.

  8. Van der Waals metal-semiconductor junction: Weak Fermi level pinning enables effective tuning of Schottky barrier

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

    Liu, Yuanyue; Stradins, Paul; Wei, Su -Huai

    2016-04-22

    Two-dimensional (2D) semiconductors have shown great potential for electronic and optoelectronic applications. However, their development is limited by a large Schottky barrier (SB) at the metal-semiconductor junction (MSJ), which is difficult to tune by using conventional metals because of the effect of strong Fermi level pinning (FLP). We show that this problem can be overcome by using 2D metals, which are bounded with 2D semiconductors through van der Waals (vdW) interactions. This success relies on a weak FLP at the vdW MSJ, which is attributed to the suppression of metal-induced gap states. Consequently, the SB becomes tunable and can vanishmore » with proper 2D metals (for example, H-NbS2). This work not only offers new insights into the fundamental properties of heterojunctions but also uncovers the great potential of 2D metals for device applications.« less

  9. Compact two-electron wave function for bond dissociation and Van der Waals interactions: A natural amplitude assessment

    SciTech Connect (OSTI)

    Giesbertz, Klaas J. H.; Leeuwen, Robert van

    2014-05-14

    Electron correlations in molecules can be divided in short range dynamical correlations, long range Van der Waals type interactions, and near degeneracy static correlations. In this work, we analyze for a one-dimensional model of a two-electron system how these three types of correlations can be incorporated in a simple wave function of restricted functional form consisting of an orbital product multiplied by a single correlation function f?(r{sub 12}) depending on the interelectronic distance r{sub 12}. Since the three types of correlations mentioned lead to different signatures in terms of the natural orbital (NO) amplitudes in two-electron systems, we make an analysis of the wave function in terms of the NO amplitudes for a model system of a diatomic molecule. In our numerical implementation, we fully optimize the orbitals and the correlation function on a spatial grid without restrictions on their functional form. Due to this particular form of the wave function, we can prove that none of the amplitudes vanishes and moreover that it displays a distinct sign pattern and a series of avoided crossings as a function of the bond distance in agreement with the exact solution. This shows that the wave function ansatz correctly incorporates the long range Van der Waals interactions. We further show that the approximate wave function gives an excellent binding curve and is able to describe static correlations. We show that in order to do this the correlation function f?(r{sub 12}) needs to diverge for large r{sub 12} at large internuclear distances while for shorter bond distances it increases as a function of r{sub 12} to a maximum value after which it decays exponentially. We further give a physical interpretation of this behavior.

  10. Magic ratio of window width to grating period for van der Waals potential measurements using material gratings

    SciTech Connect (OSTI)

    Lonij, Vincent P. A.; Holmgren, William F.; Cronin, Alexander D.

    2009-12-15

    We report improved precision measurements of the van der Waals potential strength (C{sub 3}) for Na atoms and a silicon-nitride (SiN{sub x}) surface. We studied diffraction from nanofabricated gratings with a particular 'magic' open fraction that allows us to determine C{sub 3} without the need for separate measurements of the width of the grating openings. Therefore, finding the magic open fraction improves the precision of C{sub 3} measurements. The same effect is demonstrated for a grating with an arbitrary open fraction by rotating it to a particular 'magic' angle, yielding C{sub 3}=3.42+-0.19 eV A{sup 3} for Na and a SiN{sub x} surface. This precision is sufficient to detect a change in C{sub 3} due to a thin metal coating on the grating surface. We discuss the contribution to C{sub 3} of core electrons and edge effects.

  11. Potential energy surface of the CO{sub 2}–N{sub 2} van der Waals complex

    SciTech Connect (OSTI)

    Nasri, Sameh; Ajili, Yosra; Jaidane, Nejm-Eddine; Kalugina, Yulia N.; Halvick, Philippe; Stoecklin, Thierry; Hochlaf, Majdi

    2015-05-07

    Four-dimensional potential energy surface (4D-PES) of the atmospherically relevant CO{sub 2}–N{sub 2} van der Waals complex is generated using the explicitly correlated coupled cluster with single, double, and perturbative triple excitation (CCSD(T)-F12) method in conjunction with the augmented correlation consistent triple zeta (aug-cc-pVTZ) basis set. This 4D-PES is mapped along the intermonomer coordinates. An analytic fit of this 4D-PES is performed. Our extensive computations confirm that the most stable form corresponds to a T-shape structure where the nitrogen molecule points towards the carbon atom of CO{sub 2}. In addition, we located a second isomer and two transition states in the ground state PES of CO{sub 2}–N{sub 2}. All of them lay below the CO{sub 2} + N{sub 2} dissociation limit. This 4D-PES is flat and strongly anisotropic along the intermonomer coordinates. This results in the possibility of the occurrence of large amplitude motions within the complex, such as the inversion of N{sub 2}, as suggested in the recent spectroscopic experiments. Finally, we show that the experimentally established deviations from the C{sub 2v} structure at equilibrium for the most stable isomer are due to the zero-point out-of-plane vibration correction.

  12. Two-dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy

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

    Li, Xufan; Lin, Ming-Wei; Lin, Junhao; Huang, Bing; Puretzky, Alexander A.; Ma, Cheng; Wang, Kai; Zhou, Wu; Pantelides, Sokrates T.; Chi, Miaofang; et al

    2016-04-01

    Two-dimensional (2D) heterostructures hold the promise for future atomically-thin electronics and optoelectronics due to their diverse functionalities. While heterostructures consisting of different transition metal dichacolgenide monolayers with well-matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) or edge epitaxy, constructing heterostructures from monolayers of layered semiconductors with large lattice misfits still remains challenging. Here, we report the growth of monolayer GaSe/MoSe2 heterostructures with large lattice misfit by two-step chemical vapor deposition (CVD). Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well-aligned lattice orientation between themore » two layers, forming an incommensurate vdW heterostructure. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructure at the crystal interface. Such vertically-stacked vdW GaSe/MoSe2 heterostructures are shown to form p-n junctions with effective transport and separation of photo-generated charge carriers between layers, resulting in a gate-tunable photovoltaic response. In conclusion, these GaSe/MoSe2 vdW heterostructures should have applications as gate-tunable field-effect transistors, photodetectors, and solar cells.« less

  13. Van der Waals epitaxial growth of two-dimensional single-crystalline GaSe domains on graphene

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

    Li, Xufan; Basile, Leonardo; Huang, Bing; Ma, Cheng; Lee, Jaekwang; Vlassiouk, Ivan V.; Puretzky, Alexander A.; Lin, Ming -Wei; Chi, Miaofang; Idrobo Tapia, Juan Carlos; et al

    2015-07-22

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to stamping, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here, we explore the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. Guided by the wrinkles on graphene, GaSe nuclei form that share a predominant lattice orientation. Due to vdW epitaxial growth many nuclei grow as perfectly aligned crystals and coalesce to form large (tens of microns), single-crystal flakes. Through theoretical investigationsmore » of interlayer energetics, and measurements of preferred orientations by atomic-resolution STEM and electron diffraction, a 10.9 interlayer rotation of the GaSe lattice with respect to the underlying graphene is found to be the most energetically preferred vdW heterostructure with the largest binding energy and the longest-range ordering. These GaSe/Gr vdW heterostructures exhibit an enhanced Raman E21g band of monolayer GaSe along with highly-quenched photoluminescence due to strong charge transfer. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.« less

  14. Van der Waals epitaxial growth of two-dimensional single-crystalline GaSe domains on graphene

    SciTech Connect (OSTI)

    Li, Xufan; Basile, Leonardo; Huang, Bing; Ma, Cheng; Lee, Jaekwang; Vlassiouk, Ivan V.; Puretzky, Alexander A.; Lin, Ming -Wei; Chi, Miaofang; Idrobo Tapia, Juan Carlos; Rouleau, Christopher M.; Sumpter, Bobby G.; Yoon, Mina; Geohegan, David B.; Xiao, Kai

    2015-07-22

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to stamping, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here, we explore the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. Guided by the wrinkles on graphene, GaSe nuclei form that share a predominant lattice orientation. Due to vdW epitaxial growth many nuclei grow as perfectly aligned crystals and coalesce to form large (tens of microns), single-crystal flakes. Through theoretical investigations of interlayer energetics, and measurements of preferred orientations by atomic-resolution STEM and electron diffraction, a 10.9 interlayer rotation of the GaSe lattice with respect to the underlying graphene is found to be the most energetically preferred vdW heterostructure with the largest binding energy and the longest-range ordering. These GaSe/Gr vdW heterostructures exhibit an enhanced Raman E21g band of monolayer GaSe along with highly-quenched photoluminescence due to strong charge transfer. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.

  15. Van der Waals Epitaxial Growth of Single-Crystal Two-Dimensional GaSe on Graphene

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

    Li, Xufan; Basile, Leonardo; Huang, Bing; Ma, Cheng; Lee, Jaekwang; Vlassiouk, Ivan V.; Puretzky, Alexander A.; Lin, Ming-Wei; Chi, Miaofang; Idrobo Tapia, Juan Carlos; et al

    2015-07-22

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to stamping, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here, we explore the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. Guided by the wrinkles on graphene, GaSe nuclei form that share a predominant lattice orientation. Due to vdW epitaxial growth many nuclei grow as perfectly aligned crystals and coalesce to form large (tens of microns), single-crystal flakes. Through theoretical investigationsmoreof interlayer energetics, and measurements of preferred orientations by atomic-resolution STEM and electron diffraction, a 10.9 interlayer rotation of the GaSe lattice with respect to the underlying graphene is found to be the most energetically preferred vdW heterostructure with the largest binding energy and the longest-range ordering. These GaSe/Gr vdW heterostructures exhibit an enhanced Raman E21g band of monolayer GaSe along with highly-quenched photoluminescence due to strong charge transfer. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.less

  16. C{sub 6}H{sub 6}/Au(111): Interface dipoles, band alignment, charging energy, and van der Waals interaction

    SciTech Connect (OSTI)

    Abad, E.; Martinez, J. I.; Flores, F.; Ortega, J.; Dappe, Y. J.

    2011-01-28

    We analyze the benzene/Au(111) interface taking into account charging energy effects to properly describe the electronic structure of the interface and van der Waals interactions to obtain the adsorption energy and geometry. We also analyze the interface dipoles and discuss the barrier formation as a function of the metal work-function. We interpret our DFT calculations within the induced density of interface states (IDIS) model. Our results compare well with experimental and other theoretical results, showing that the dipole formation of these interfaces is due to the charge transfer between the metal and benzene, as described in the IDIS model.

  17. Combining density functional and incremental post-Hartree-Fock approaches for van der Waals dominated adsorbate-surface interactions: Ag{sub 2}/graphene

    SciTech Connect (OSTI)

    Lara-Castells, María Pilar de; Mitrushchenkov, Alexander O.; Stoll, Hermann

    2015-09-14

    A combined density functional (DFT) and incremental post-Hartree-Fock (post-HF) approach, proven earlier to calculate He-surface potential energy surfaces [de Lara-Castells et al., J. Chem. Phys. 141, 151102 (2014)], is applied to describe the van der Waals dominated Ag{sub 2}/graphene interaction. It extends the dispersionless density functional theory developed by Pernal et al. [Phys. Rev. Lett. 103, 263201 (2009)] by including periodic boundary conditions while the dispersion is parametrized via the method of increments [H. Stoll, J. Chem. Phys. 97, 8449 (1992)]. Starting with the elementary cluster unit of the target surface (benzene), continuing through the realistic cluster model (coronene), and ending with the periodic model of the extended system, modern ab initio methodologies for intermolecular interactions as well as state-of-the-art van der Waals-corrected density functional-based approaches are put together both to assess the accuracy of the composite scheme and to better characterize the Ag{sub 2}/graphene interaction. The present work illustrates how the combination of DFT and post-HF perspectives may be efficient to design simple and reliable ab initio-based schemes in extended systems for surface science applications.

  18. Including screening in van der Waals corrected density functional theory calculations: The case of atoms and small molecules physisorbed on graphene

    SciTech Connect (OSTI)

    Silvestrelli, Pier Luigi; Ambrosetti, Alberto

    2014-03-28

    The Density Functional Theory (DFT)/van der Waals-Quantum Harmonic Oscillator-Wannier function (vdW-QHO-WF) method, recently developed to include the vdW interactions in approximated DFT by combining the quantum harmonic oscillator model with the maximally localized Wannier function technique, is applied to the cases of atoms and small molecules (X=Ar, CO, H{sub 2}, H{sub 2}O) weakly interacting with benzene and with the ideal planar graphene surface. Comparison is also presented with the results obtained by other DFT vdW-corrected schemes, including PBE+D, vdW-DF, vdW-DF2, rVV10, and by the simpler Local Density Approximation (LDA) and semilocal generalized gradient approximation approaches. While for the X-benzene systems all the considered vdW-corrected schemes perform reasonably well, it turns out that an accurate description of the X-graphene interaction requires a proper treatment of many-body contributions and of short-range screening effects, as demonstrated by adopting an improved version of the DFT/vdW-QHO-WF method. We also comment on the widespread attitude of relying on LDA to get a rough description of weakly interacting systems.

  19. Persistent photoconductivity in two-dimensional Mo1-xW xSe2–MoSe2 van der Waals heterojunctions

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

    Puretzky, Alexander A.; Basile, Leonardo; Idrobo, Juan Carlos; Rouleau, Christopher M.; Geohegan, David B.; Xiao, Kai; Li, Xufan; Lin, Ming -Wei; Wang, Kei

    2016-02-16

    Van der Waals (vdW) heterojunctions consisting of vertically-stacked individual or multiple layers of two-dimensional (2D) layered semiconductors, especially the transition metal dichalcogenides (TMDs), are fascinating new artificial solids just nanometers-thin that promise novel optoelectronic functionalities due to the sensitivity of their electronic and optical properties to strong quantum confinement and interfacial interactions. Here, monolayers of n-type MoSe2 and p-type Mo1-xW xSe2–MoSe2 are grown by vapor transport methods, then transferred and stamped to form artificial vdW heterostructures with different interlayer orientations. Atomic-resolution Z-contrast electron microscopy and electron diffraction are used to characterize both the individual monolayers and the atomic registry betweenmore » layers in the bilayer vdW heterostructures. These measurements are compared with photoluminescence and low-frequency Raman spectroscopy, which indicates strong interlayer coupling in heterostructures. Remarkably, the heterojunctions exhibit an unprecedented photoconductivity effect that persists at room temperature for several days. This persistent photoconductivity is shown to be tunable by applying a gate bias that equilibrates the charge distribution. Furthermore, these measurements indicate that such ultrathin vdW heterojunctions can function as rewritable optoelectronic switches or memory elements under time-dependent photo-illumination, an effect which appears promising for new monolayer TMDs-based optoelectronic devices applications.« less

  20. Van Hove's Birthday

    ScienceCinema (OSTI)

    None

    2011-04-25

    "Happy Birthday Léon!" Plusieurs orateurs rendent hommage à L.Van Hove et son travail à l'occasion de son 65me anniversaire. A la fin remerciements de L.Van Hove.

  1. Bruno Van Wonterghem

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

    bruno van wonterghem Bruno Van Wonterghem Bruno Van Wonterghem Operations Manager National Ignition Facility Dr. Bruno Van Wonterghem became commissioning manager of NIF in 2001 and operations manager in 2008. He earned his Ph.D. in chemical physics at the University of Leuven in Belgium in 1987. He has extensive experience in developing laser systems for plasma research in academia through work at the University of California, Irvine; the Max Planck Institute; and LLNL. He was manager of

  2. Photodissociation of (SO{sub 2}?XH) Van der Waals complexes and clusters (XH = C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}) excited at 32?04032?090 cm{sup ?1} with formation of HSO{sub 2} and X

    SciTech Connect (OSTI)

    Makarov, Vladimir I.; Kochubei, Sergei A.; Khmelinskii, Igor

    2014-02-07

    We studied photodecomposition dynamics of (SO{sub 2}?XH) Van der Waals (VdW) complexes and clusters in gas phase, with X = C{sub 2}H, C{sub 2}H{sub 3}, and C{sub 2}H{sub 5}. SO{sub 2} was excited by frequency-doubled radiation of a tunable dye laser and resonance-enhanced multiphoton ionization was used to detect the C{sub 2}H (m/z 25), C{sub 2}H{sub 3} (m/z 27), and C{sub 2}H{sub 5} (m/z 29) ions by time-of-flight mass spectroscopy. Spectra obtained at higher nozzle pressures (P{sub 0} > 2.5 atm) indicate formation of clusters. Detailed studies of the VdW complex structure were carried out by analyzing the rotational structure of the respective action spectra. We also performed ab initio theoretical analysis of structures of the VdW complexes and transitional states leading to photodecomposition. We find that the structure of the transition state is significantly different as compared to the equilibrium ground-state structure of the respective complex. The photodecomposition mechanism depends on the hydrocarbon molecule bound to SO{sub 2}.

  3. Bruno Van Wonterghem

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

    bruno van wonterghem Bruno Van Wonterghem Operations Manager Keeps NIF Trekking Bruno Van Wonterghem Bruno Van Wonterghem Do you remember when you started being interested in science? My uncle was a radiochemistry professor, and I would go to the lab with him every Wednesday. He had one of the first calculators, the size of a briefcase. I could see it think with its lights flickering and parts moving back and forth. A simple square root would take seconds to calculate. My grandfather was a

  4. Jack VanKuiken | Argonne National Laboratory

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

    Jack VanKuiken Systems Engineer E-mail jvankuiken

  5. Propane Bakery Delivery Step Vans

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Case Study - Propane Bakery Delivery Step Vans April 2016 1 Contents Background .......................................................................................................................................................................... 3 Motivation for Adopting Propane ................................................................................................................................... 3 Financial Benefits

  6. Collective many-body van der Waals interactions in molecular...

    Office of Scientific and Technical Information (OSTI)

    Research Org: Argonne National Laboratory (ANL) Sponsoring Org: SC OFFICE OF BASIC ENERGY SCIENCES Country of Publication: United States Language: ENGLISH Word Cloud More Like This ...

  7. Rienk van Grondelle | Photosynthetic Antenna Research Center

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

    Rienk van Grondelle Rienk van Grondelle Rienk van Grondelle Rienk van Grondelle Research Affiliate E-mail: r.van.grondelle@vu.nl Dr. van Grondelle's research focuses on trying to understand the physical basis of photosynthesis. Professor of Biophysics, Head of the Department of Physics and Astronomy Research Affiliates

  8. Julie Crenshaw Van Fleet

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

    Crenshaw Van Fleet 127 S. Fairfax Street, PMB#110 Alexandria, VA 22314 7 January 2007 Mr. Samuel W. Bodman Secretary of Energy Via Mr. Anthony J. Comco SEA Document Manager US DOE anthony.comco@hq.doe.gov 202/287-5736 fax and Ms. Carol Borgstrom, Director Office of NEPA Policy and Compliance US DOE askNEPA@hq.doe.gov 202/586-7031 fax RE: DOE/SEA-04, Special Environmental Analysis: For Actions Taken Under U.S. Department of Energy Emergency Orders Regarding Operation of the Potomac River

  9. Victor Der | Department of Energy

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

    Victor Der About Us Victor Der - Former Principal Deputy Assistant Secretary, Office of Fossil Energy Victor Der is the former Principal Deputy Assistant Secretary for Fossil Energy. Most Recent Cleaning Up Coal August 13

  10. Brie Van Cleve | Department of Energy

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

    Brie Van Cleve About Us Brie Van Cleve - Former Stakeholder Engagement and Outreach Manager, Wind and Water Power Technologies Office Most Recent Mapping the Frontier of New Wind ...

  11. Noah Van Dam | Argonne National Laboratory

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

    Noah Van Dam Postdoctoral Appointee E-mail nvandam@anl.gov Website Google Scholar

  12. Van Ness Feldman | Open Energy Information

    Open Energy Info (EERE)

    Feldman Jump to: navigation, search Name: Van Ness Feldman Place: Washington, D.C., Washington, DC Zip: 20007 Product: Van Ness Feldman is a law firm concentrating on government...

  13. Heidi VanGenderen | Department of Energy

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

    VanGenderen has helped implement a multi-faceted public engagement and outreach program to ... VanGenderen has worked on energy and climate issues in the non-profit, public, academic, ...

  14. vanDuin_ReaxFF

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

    Voltage profile for Li- graphite system obtained by ReaxFF. (b) Li ordering in stage I LiC 6 compounds . FIRST Center Research Perspective: ReaxFF Reactive Force Field Development and Applications. Muralikrishna Raju, Alireza Ostadhossein and Adri van Duin The Pennsylvania State University Jennifer Achtyl and Franz Geiger Northwestern University Panchapakesan Ganesh and Paul Kent Oak Ridge National Laboratory Research Summary: The ReaxFF method enables large-scale (>> 1000 atoms) dynamics

  15. Picture of the Week: Bulging Van Allen Belts

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

    2 Bulging Van Allen Belts Learn about the Van Allen Belts and how new findings from NASA's Van Allen Probes could impact how we protect technology in space. February 25, 2016 Bulging Van Allen Belts Watch the video on YouTube. Bulging Van Allen Belts Learn about the Van Allen Belts and how new findings from NASA's Van Allen Probes could impact how we protect technology in space

  16. Van Allen Probes observation and modeling of chorus excitation...

    Office of Scientific and Technical Information (OSTI)

    Van Allen Probes observation and modeling of chorus excitation and propagation during weak ... This content will become publicly available on August 20, 2016 Title: Van Allen Probes ...

  17. IN MEMORIAM: Dr. Abraham (Abe) Van Luik

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

    11, 2016 IN MEMORIAM: Dr. Abraham (Abe) Van Luik The Carlsbad Field Office (CBFO) workforce is saddened by the recent loss of Dr. Abraham (Abe) Van Luik. Abe was a key member of the CBFO team and was well respected at DOE and in the international community. Abe led the CBFO International Repository Science Program. His work included contributions to coordinated research and sharing of results through bilateral and multilateral cooperation. Interacting with several international organizations, he

  18. Alternative Fuels Data Center: Propane Vans Keep Kansas City Transportation

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Company Rolling Propane Vans Keep Kansas City Transportation Company Rolling to someone by E-mail Share Alternative Fuels Data Center: Propane Vans Keep Kansas City Transportation Company Rolling on Facebook Tweet about Alternative Fuels Data Center: Propane Vans Keep Kansas City Transportation Company Rolling on Twitter Bookmark Alternative Fuels Data Center: Propane Vans Keep Kansas City Transportation Company Rolling on Google Bookmark Alternative Fuels Data Center: Propane Vans Keep

  19. OSTIblog Articles in the James Van Allen Topic | OSTI, US Dept...

    Office of Scientific and Technical Information (OSTI)

    James Van Allen Topic James Van Allen - Space Pioneer by Kathy Chambers 10 Jun, 2016 in jamesvanallenwcaption.jpg James Van Allen's space instrumentation innovations and his... ...

  20. CO2 Capture by Metal-Organic Frameworks with van der Waals Density...

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

    However, two specific vdW-DFs result in excellent agreement with experiments within a few kilojoules per mole, at a reduced computational cost compared to quantum chemistry or ...

  1. Spintronics with graphene-hexagonal boron nitride van der Waals heterostructures

    SciTech Connect (OSTI)

    Kamalakar, M. Venkata Dankert, André; Bergsten, Johan; Ive, Tommy; Dash, Saroj P.

    2014-11-24

    Hexagonal boron nitride (h-BN) is a large bandgap insulating isomorph of graphene, ideal for atomically thin tunnel barrier applications. In this letter, we demonstrate large area chemical vapor deposited (CVD) h-BN as a promising spin tunnel barrier in graphene spin transport devices. In such structures, the ferromagnetic tunnel contacts with h-BN barrier are found to show robust tunneling characteristics over a large scale with resistances in the favorable range for efficient spin injection into graphene. The non-local spin transport and precession experiments reveal spin lifetime ≈500 ps and spin diffusion length ≈1.6 μm in graphene with tunnel spin polarization ≈11% at 100 K. The electrical and spin transport measurements at different injection bias current and gate voltages confirm tunnel spin injection through h-BN barrier. These results open up possibilities for implementation of large area CVD h-BN in spintronic technologies.

  2. Ancillary Services Provided from DER

    SciTech Connect (OSTI)

    Campbell, J.B.

    2005-12-21

    Distributed energy resources (DER) are quickly making their way to industry primarily as backup generation. They are effective at starting and then producing full-load power within a few seconds. The distribution system is aging and transmission system development has not kept up with the growth in load and generation. The nation's transmission system is stressed with heavy power flows over long distances, and many areas are experiencing problems in providing the power quality needed to satisfy customers. Thus, a new market for DER is beginning to emerge. DER can alleviate the burden on the distribution system by providing ancillary services while providing a cost adjustment for the DER owner. This report describes 10 types of ancillary services that distributed generation (DG) can provide to the distribution system. Of these 10 services the feasibility, control strategy, effectiveness, and cost benefits are all analyzed as in the context of a future utility-power market. In this market, services will be provided at a local level that will benefit the customer, the distribution utility, and the transmission company.

  3. PARC Seminar Series featuring Rienk van Grondelle | Photosynthetic Antenna

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

    Research Center PARC Seminar Series featuring Rienk van Grondelle PARC Seminar Series featuring Rienk van Grondelle October 4, 2016 - 11:00am Brauer Hall room 12

  4. Van Buren Light & Power Dist | Open Energy Information

    Open Energy Info (EERE)

    Van Buren Light & Power Dist Jump to: navigation, search Name: Van Buren Light & Power Dist Place: Maine Phone Number: (207) 868-3321 Website: www.cmpco.comSuppliersAndPart Outage...

  5. james_van_allen_wcaption.jpg | OSTI, US Dept of Energy Office of Scientific

    Office of Scientific and Technical Information (OSTI)

    and Technical Information james_van_allen_wcaption

  6. A new picture of the Van Allen Belts

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

    A new picture of the Van Allen Belts A new picture of the Van Allen Belts A study conducted by Los Alamos and the New Mexico Consortium reveals that the shape of the Van Allen Belts is actually quite different than previously believed. January 21, 2016 van allen belts During geomagnetic storms, the empty region between the two belts can fill in completely with lower-energy electrons. Traditionally, scientists thought this slot region filled in only during the most extreme geomagnetic storms

  7. Van Allen probes pinpoint driver of speeding electrons

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

    Van Allen probes pinpoint driver of speeding electrons Van Allen probes pinpoint driver of speeding electrons Los Alamos researchers believe they have solved a lingering mystery about how electrons within Earth's radiation belt can suddenly become energetic enough to kill orbiting satellites. July 25, 2013 Artist's rendering of mechanism within Van Allen radiation belts An artist's rendering of a mechanism within the Van Allen radiation belts that can accelerate electrons to satellite-killing

  8. Peter Van Gemmeren | Argonne National Laboratory

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

    Van Gemmeren Software Engineer Ph.D., Physics from Johannes Gutenberg University Mainz in Germany 1998. Diploma (Masters), Physics from Universität Siegen in Germany 1995. Member of the High Energy Physic Computing Group developing core software for the ATLAS experiment at CERN. Provided design, development and deployment of robust functional software needed by researchers to conduct and analyze physics experiments, with particular emphasis on database (Oracle, MySQL, SciDB), Input/Output

  9. R. Bruce van Dover > ProfessorMaterials Science and Engineering...

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

    Topical Group on Magnetism and Its Applications, a unit of the American Physical Society. Research Prof. van Dover's research is currently focused on exploring the properties of...

  10. Van Andel Research Institute, Los Alamos National Laboratory...

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

    Computational model to study lung cancer Van Andel Research Institute, Los Alamos National Laboratory to develop detailed computational model to study lung cancer Scientists are...

  11. Van Norman Residences Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Norman Residences Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Van Norman Residences Space Heating Low Temperature Geothermal Facility...

  12. Van Wert County, Ohio: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    County, Ohio Convoy, Ohio Delphos, Ohio Elgin, Ohio Middle Point, Ohio Ohio City, Ohio Scott, Ohio Van Wert, Ohio Venedocia, Ohio Willshire, Ohio Wren, Ohio Retrieved from "http:...

  13. United Parcel Service Evaluates Hybrid Electric Delivery Vans (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-02-01

    This fact sheet describes how the National Renewable Energy Laboratory's Fleet Test and Evaluation team evaluated the 12-month, in-service performance of six Class 4 hybrid electric delivery vans - fueled by regular diesel - and six comparable conventional diesel vans operated by the United Parcel Service.

  14. Graded Interface Models for more accurate Determination of van...

    Office of Scientific and Technical Information (OSTI)

    length scale property variations. Authors: van Benthem, Klaus 1 ; Tan, Guolong 2 ; French, Roger H 3 ; DeNoyer, Linda K 4 ; Podgornik, Rudolf 5 ; Parsegian, V Adrian 5...

  15. April VanCamp Gil | Department of Energy

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

    A Colorado native, Dr. April VanCamp Gil is happy to be home where she manages the historic Grand Junction, Colorado, Office, which traces its origins to World War II and the ...

  16. Bakery Switches to Propane Vans | Argonne National Laboratory

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

    Bakery Switches to Propane Vans By Jo Napolitano * April 21, 2016 Tweet EmailPrint A switch to propane from diesel by a major Midwest bakery fleet showed promising results, ...

  17. Isotopic Analysis At Separation Creek Area (Van Soest, Et Al...

    Open Energy Info (EERE)

    Usefulness useful DOE-funding Unknown References M. C. van Soest, B. M. Kennedy, W. C. Evans, R. H. Mariner (2002) Mantle Helium And Carbon Isotopes In Separation Creek...

  18. A P van den Berg | Open Energy Information

    Open Energy Info (EERE)

    to: navigation, search Name: A. P. van den Berg Place: Heerenveen, Netherlands Zip: P.O. Box 68, 8440 AB Sector: Geothermal energy, Solar Product: Designs and installs soil...

  19. Van Andel Research Institute, Los Alamos National Laboratory to develop

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

    detailed computational model to study lung cancer Computational model to study lung cancer Van Andel Research Institute, Los Alamos National Laboratory to develop detailed computational model to study lung cancer Scientists are developing a new tool to better study one of the deadliest types of lung cancer. September 14, 2015 Even the most carefully crafted science projects starts with a rough brainstorm session. This whiteboard is from an early Los Alamos National Laboratory and Van Andel

  20. Study finds surprising variability in shape of Van Allen Belts

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

    Study finds surprising variability in shape of Van Allen Belts Study finds surprising variability in shape of Van Allen Belts Understanding the shape and size of the belts, which shrink and swell in response to magnetic storms coming from the sun, is crucial for protecting our technology in space. February 23, 2016 1. The traditional idea of the radiation belts includes a larger, more dynamic outer belt and a smaller, more stable inner belt with an empty slot region separating the two. However,

  1. OSTIblog Articles in the James Van Allen Topic | OSTI, US Dept of Energy

    Office of Scientific and Technical Information (OSTI)

    Office of Scientific and Technical Information James Van Allen Topic James Van Allen - Space Pioneer by Kathy Chambers 10 Jun, 2016 in james_van_allen_wcaption.jpg James Van Allen's space instrumentation innovations and his advocacy for Earth satellite planetary missions ensured his place among the early leaders of space exploration. After World War II, Van Allen begin his atmospheric research at the Johns Hopkins University Applied Physics Laboratory and Brookhaven National Laboratory. He

  2. DER-CAM V3.10.5M

    Energy Science and Technology Software Center (OSTI)

    003010IBMPC04 Distributed Energy Resources Customer Adoption Model (DER-CAM), Investment & Planing Version 3.10.5.m

  3. Magnetic structure and phase stability of the van der Waals bonded ferromagnet Fe3-xGeTe2

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

    May, Andrew F.; Calder, Stuart A.; Cantoni, Claudia; Cao, Huibo; McGuire, Michael A.

    2016-01-08

    The magnetic structure and phase diagram of the layered ferromagnetic compound Fe3GeTe2 have been investigated by a combination of synthesis, x-ray and neutron diffraction, high-resolution microscopy, and magnetization measurements. Single crystals were synthesized by self-flux reactions, and single-crystal neutron diffraction finds ferromagnetic order with moments of 1.11(5)μB/Fe aligned along the c axis at 4 K. These flux-grown crystals have a lower Curie temperature Tc ≈ 150 K than crystals previously grown by vapor transport (Tc = 220 K). The difference is a reduced Fe content in the flux-grown crystals, as illustrated by the behavior observed in a series of polycrystallinemore » samples. As Fe content decreases, so do the Curie temperature, magnetic anisotropy, and net magnetization. Furthermore, Hall-effect and thermoelectric measurements on flux-grown crystals suggest that multiple carrier types contribute to electrical transport in Fe3–xGeTe2 and structurally similar Ni3–xGeTe2.« less

  4. Natural Gas Vans To Help Clear the Air In Metro Denver

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

    SuperShuttle purchased the 10 compressed natural gas (CNG) vans to transport passengers ... Five of the 10 new vans are dedicated fuel vehicles, which means they run only on CNG. The ...

  5. Twelve-Month Evaluation of UPS Diesel Hybrid Electric Delivery Vans

    SciTech Connect (OSTI)

    Lammert, M.

    2009-12-01

    Results of an NREL study of a parallel hybrid electric-diesel propulsion system in United Parcel Service-operated delivery vans show that the hybrids had higher fuel economy than standard diesel vans.

  6. NREL Study: Hybrid Delivery Vans Show Nearly 20 Percent Higher Fuel Economy

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

    - News Releases | NREL Study: Hybrid Delivery Vans Show Nearly 20 Percent Higher Fuel Economy September 28, 2012 The U.S. Department of Energy's (DOE)'s National Renewable Energy Laboratory (NREL) recently completed a performance evaluation report that showed significant fuel economy benefits of hybrid electric delivery vans compared to similar conventional vans. "During the on-road portion of our study, the hybrid vans demonstrated a 13 to 20 percent higher fuel economy than the

  7. Research at the BNL Tandem Van de Graaff Facility, 1980

    SciTech Connect (OSTI)

    Not Available

    1981-03-01

    Research programs at the Brookhaven Van de Graaff accelerators are summarized. Major accomplishments of the laboratory are discussed including quasielastic reactions, high-spin spectroscopy, yrast spectra, fusion reactions, and atomic physics. The outside user program at the Laboratory is discussed. Research proposed for 1981 is outlined. (GHT)

  8. 3rd Annual National CHP Roadmap Workshop CHP and DER for Federal...

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

    National CHP Roadmap Workshop CHP and DER for Federal Facilities EPA CHP Partnership Meeting, October 2002 3rd Annual National CHP Roadmap Workshop CHP and DER for Federal ...

  9. Evaluation of Distribution Analysis Software for DER Applications

    SciTech Connect (OSTI)

    Staunton, RH

    2003-01-23

    The term ''Distributed energy resources'' or DER refers to a variety of compact, mostly self-contained power-generating technologies that can be combined with energy management and storage systems and used to improve the operation of the electricity distribution system, whether or not those technologies are connected to an electricity grid. Implementing DER can be as simple as installing a small electric generator to provide backup power at an electricity consumer's site. Or it can be a more complex system, highly integrated with the electricity grid and consisting of electricity generation, energy storage, and power management systems. DER devices provide opportunities for greater local control of electricity delivery and consumption. They also enable more efficient utilization of waste heat in combined cooling, heating and power (CHP) applications--boosting efficiency and lowering emissions. CHP systems can provide electricity, heat and hot water for industrial processes, space heating and cooling, refrigeration, and humidity control to improve indoor air quality. DER technologies are playing an increasingly important role in the nation's energy portfolio. They can be used to meet base load power, peaking power, backup power, remote power, power quality, as well as cooling and heating needs. DER systems, ranging in size and capacity from a few kilowatts up to 50 MW, can include a number of technologies (e.g., supply-side and demand-side) that can be located at or near the location where the energy is used. Information pertaining to DER technologies, application solutions, successful installations, etc., can be found at the U.S. Department of Energy's DER Internet site [1]. Market forces in the restructured electricity markets are making DER, both more common and more active in the distribution systems throughout the US [2]. If DER devices can be made even more competitive with central generation sources this trend will become unstoppable. In response, energy

  10. NREL Evaluates UPS Hybrid-Electric Van Performance - News Releases | NREL

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

    NREL Evaluates UPS Hybrid-Electric Van Performance New trucks deliver more than 28% fuel savings December 22, 2009 The U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) has collected and analyzed fuel economy, maintenance and other vehicle performance data from UPS's first generation hybrid diesel step delivery vans powered by an Eaton Corp. electric hybrid propulsion system. The diesel hybrid delivery vans improved the on-road fuel economy by 28.9 percent resulting

  11. Ms Van T Nguyen | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Van T Nguyen Scientific User Facilities (SUF) Division SUF Home About Staff Dr. James B. Murphy What's New User Facilities Projects Accelerator & Detector Research Science Highlights Principal Investigators' Meetings BES Home Staff Ms. Van T Nguyen Print Text Size: A A A FeedbackShare Page Van T. Nguyen Program Manager Facility Coordination, Metrics, and Assessment Office of Basic Energy Sciences SC-22.3/Germantown Building U.S. Department of Energy 1000 Independence Avenue, SW Washington,

  12. Interim Project Results: United Parcel Service's Second-Generation Hybrid-Electric Delivery Vans (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-01-01

    This fact sheet describes the performance evaluation of United Parcel Service's second-generation hybrid-electric delivery vans. The Fleet Test and Evaluation Team at the National Renewable Energy Laboratory (NREL) is evaluating the 18-month, in-service performance of 11 of these vans along with 11 comparable conventional diesel vans operating in Minneapolis, Minnesota. As a complement to the field study, the team recently completed fuel economy and emissions testing at NREL's Renewable Fuels and Lubricants (ReFUEL) laboratory.

  13. Project Overview: United Parcel Service's Second-Generation Hybrid-Electric Delivery Vans (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-11-01

    This fact sheet describes UPS second generation hybrid-electric delivery vehicles as compared to conventional delivery vehicles. Medium-duty commercial vehicles such as moving trucks, beverage-delivery trucks, and package-delivery vans consume almost 2,000 gal of fuel per year on average. United Parcel Service (UPS) operates hybrid-electric package-delivery vans to reduce the fuel use and emissions of its fleet. In 2008, the National Renewable Energy Laboratory's (NREL's) Fleet Test and Evaluation Team evaluated the first generation of UPS' hybrid delivery vans. These hybrid vans demonstrated 29%-37% higher fuel economy than comparable conventional diesel vans, which contributed to UPS' decision to add second-generation hybrid vans to its fleet. The Fleet Test and Evaluation Team is now evaluating the 18-month, in-service performance of 11 second-generation hybrid vans and 11 comparable conventional diesel vans operated by UPS in Minneapolis, Minnesota. The evaluation also includes testing fuel economy and emissions at NREL's Renewable Fuels and Lubricants (ReFUEL) Laboratory and comparing diesel particulate filter (DPF) regeneration. In addition, a followup evaluation of UPS' first-generation hybrid vans will show how those vehicles performed over three years of operation. One goal of this project is to provide a consistent comparison of fuel economy and operating costs between the second-generation hybrid vans and comparable conventional vans. Additional goals include quantifying the effects of hybridization on DPF regeneration and helping UPS select delivery routes for its hybrid vans that maximize the benefits of hybrid technology. This document introduces the UPS second-generation hybrid evaluation project. Final results will be available in mid-2012.

  14. Van Geet Off-Grid Home: An Integrated Approach to Energy Savings

    SciTech Connect (OSTI)

    2004-08-01

    The Van Geet home near Denver, Colorado, exemplifies the effectiveness of coupling energy conservation measures with renewable energy utilization in a modern residence.

  15. A background correction algorithm for Van Allen Probes MagEIS...

    Office of Scientific and Technical Information (OSTI)

    Title: A background correction algorithm for Van Allen Probes MagEIS electron flux measurements We describe an automated computer algorithm designed to remove background ...

  16. Abigail Van Wassen > Graduate Student - Abruña Group > Researchers,

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

    Postdocs & Graduates > The Energy Materials Center at Cornell Abigail Van Wassen Graduate Student - Abruña Group arv45@cornell.edu

  17. MiniBooNE Antineutrino Data Van Nguyen Columbia University

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

    Moriond EW 2008 Coherent NC π 0 Production in the MiniBooNE Antineutrino Data Van Nguyen Columbia University for the MiniBooNE collaboration Moriond EW 2008 2 Moriond EW 2008 At low energy, NC π 0 's can be created through resonant and coherent production:  Resonant NC π 0 production:  Coherent NC π 0 production: (Signature: π 0 which is highly forward-going) NC π 0 Production 3 Moriond EW 2008 Why study coherent NC π 0 production? ➔ NC π 0 events are the dominant bgd to osc

  18. Micro-Bubble Experiments at the Van de Graaff Accelerator

    SciTech Connect (OSTI)

    Sun, Z. J.; Wardle, Kent E.; Quigley, K. J.; Gromov, Roman; Youker, A. J.; Makarashvili, Vakhtang; Bailey, James; Stepinski, D. C.; Chemerisov, S. D.; Vandegrift, G. F.

    2015-02-01

    In order to test and verify the experimental designs at the linear accelerator (LINAC), several micro-scale bubble ("micro-bubble") experiments were conducted with the 3-MeV Van de Graaff (VDG) electron accelerator. The experimental setups included a square quartz tube, sodium bisulfate solution with different concentrations, cooling coils, gas chromatography (GC) system, raster magnets, and two high-resolution cameras that were controlled by a LabVIEW program. Different beam currents were applied in the VDG irradiation. Bubble generation (radiolysis), thermal expansion, thermal convection, and radiation damage were observed in the experiments. Photographs, videos, and gas formation (O2 + H2) data were collected. The micro-bubble experiments at VDG indicate that the design of the full-scale bubble experiments at the LINAC is reasonable.

  19. Advanced Communication and Control Solutions of Distributed Energy Resources (DER)

    SciTech Connect (OSTI)

    Asgeirsson, Haukur; Seguin, Richard; Sherding, Cameron; de Bruet, Andre, G.; Broadwater, Robert; Dilek, Murat

    2007-01-10

    This report covers work performed in Phase II of a two phase project whose objective was to demonstrate the aggregation of multiple Distributed Energy Resources (DERs) and to offer them into the energy market. The Phase I work (DE-FC36-03CH11161) created an integrated, but distributed, system and procedures to monitor and control multiple DERs from numerous manufacturers connected to the electric distribution system. Procedures were created which protect the distribution network and personnel that may be working on the network. Using the web as the communication medium for control and monitoring of the DERs, the integration of information and security was accomplished through the use of industry standard protocols such as secure SSL,VPN and ICCP. The primary objective of Phase II was to develop the procedures for marketing the power of the Phase I aggregated DERs in the energy market, increase the number of DER units, and implement the marketing procedures (interface with ISOs) for the DER generated power. The team partnered with the Midwest Independent System Operator (MISO), the local ISO, to address the energy market and demonstrate the economic dispatch of DERs in response to market signals. The selection of standards-based communication technologies offers the ability of the system to be deployed and integrated with other utilities’ resources. With the use of a data historian technology to facilitate the aggregation, the developed algorithms and procedures can be verified, audited, and modified. The team has demonstrated monitoring and control of multiple DERs as outlined in phase I report including procedures to perform these operations in a secure and safe manner. In Phase II, additional DER units were added. We also expanded on our phase I work to enhance communication security and to develop the market model of having DERs, both customer and utility owned, participate in the energy market. We are proposing a two-part DER energy market model--a utility

  20. Thirty-Six Month Evaluation of UPS Diesel Hybrid-Electric Delivery Vans

    SciTech Connect (OSTI)

    Lammert, M.; Walkowicz, K.

    2012-03-01

    This evaluation compared six hybrids and six standard diesels in UPS facilities in Phoenix, Arizona. Dispatch and maintenance practices are the same at both facilities. GPS logging, fueling, and maintenance records are used to evaluate the performance of these step delivery vans. The hybrids' average monthly mileage rate was 18% less than the diesel vans. The hybrids consistently were driven a fewer number of miles throughout the evaluation period. The hybrids idled more and operating at slower speeds than the diesels, and the diesels spent slightly more time operating at greater speeds, accounting for much of the hybrids fewer monthly miles. The average fuel economy for the hybrid vans is 13.0 mpg, 23% greater than the diesel vans 10.6 mpg. Total hybrid maintenance cost/mile of $0.141 was 9% more than the $0.130 for the diesel vans. Propulsion-related maintenance cost/mile of $0.037 for the hybrid vans was 25% more than the $0.029 for the diesel vans. Neither difference was found to be statistically significant. The hybrid group had a cumulative average of 96.3% uptime, less than the diesel group's 99.0% uptime. The hybrids experienced troubleshooting and recalibration issues related to prototype components that were primarily responsible for the lower uptime figures.

  1. FIA-14-0029 - In the Matter of Richard van Dijk | Department of Energy

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

    9 - In the Matter of Richard van Dijk FIA-14-0029 - In the Matter of Richard van Dijk On June 5, 2014, the Department of Energy's (DOE) Office of Hearings and Appeals (OHA) denied a Freedom of Information Act Appeal (FOIA) filed by Richard van Dijk (Appellant) of a determination issued by the Bonneville Power Administration (BPA). In its Appeal, the Appellant challenged the BPA's withholdings on pages 86-95 under Exemption 5 and on page 101 as non-responsive. OHA found that BPA's withholdings

  2. Structural and functional adaptation of vancomycin resistance VanT serine racemases

    SciTech Connect (OSTI)

    Meziane-Cherif, Djalal; Stogios, Peter J.; Evdokimova, Elena; Egorova, Olga; Savchenko, Alexei; Courvalin, Patrice

    2015-08-11

    Vancomycin resistance in Gram-positive bacteria results from the replacement of the D-alanyl–D-alanine target of peptidoglycan precursors with D-alanyl–D-lactate or D-alanyl–D-serine (D-Ala-D-Ser), to which vancomycin has low binding affinity. VanT is one of the proteins required for the production of D-Ala-D-Ser-terminating precursors by converting L-Ser to D-Ser. VanT is composed of two domains, an N-terminal membrane-bound domain, likely involved in L-Ser uptake, and a C-terminal cytoplasmic catalytic domain which is related to bacterial alanine racemases. To gain insight into the molecular function of VanT, the crystal structure of the catalytic domain of VanTG from VanG-type resistant Enterococcus faecalis BM4518 was determined. The structure showed significant similarity to type III pyridoxal 5'-phosphate (PLP)-dependent alanine racemases, which are essential for peptidoglycan synthesis. Comparative structural analysis between VanTG and alanine racemases as well as site-directed mutagenesis identified three specific active site positions centered around Asn696 which are responsible for theL-amino acid specificity. This analysis also suggested that VanT racemases evolved from regular alanine racemases by acquiring additional selectivity toward serine while preserving that for alanine. The 4-fold-lower relative catalytic efficiency of VanTG against L-Ser versus L-Ala implied that this enzyme relies on its membrane-bound domain for L-Ser transport to increase the overall rate of D-Ser production. These findings illustrate how vancomycin pressure selected for molecular adaptation of a housekeeping enzyme to a bifunctional enzyme to allow for peptidoglycan remodeling, a strategy increasingly observed in antibiotic-resistant bacteria.

  3. Energy Lab to Evaluate Performance of UPS Hybrid-Electric Vans - News

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

    Releases | NREL Energy Lab to Evaluate Performance of UPS Hybrid-Electric Vans New delivery trucks expected to save fuel, reduce harmful emissions August 23, 2007 The U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) is collecting and analyzing maintenance, fuel economy and other vehicle performance data from 50 UPS hybrid diesel step delivery vans powered by an Eaton Corp. electric hybrid propulsion system. Funded by the DOE's Advanced Vehicle Testing Activity

  4. Structural and functional adaptation of vancomycin resistance VanT serine racemases

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

    Meziane-Cherif, Djalal; Stogios, Peter J.; Evdokimova, Elena; Egorova, Olga; Savchenko, Alexei; Courvalin, Patrice

    2015-08-11

    Vancomycin resistance in Gram-positive bacteria results from the replacement of the D-alanyl–D-alanine target of peptidoglycan precursors with D-alanyl–D-lactate or D-alanyl–D-serine (D-Ala-D-Ser), to which vancomycin has low binding affinity. VanT is one of the proteins required for the production of D-Ala-D-Ser-terminating precursors by converting L-Ser to D-Ser. VanT is composed of two domains, an N-terminal membrane-bound domain, likely involved in L-Ser uptake, and a C-terminal cytoplasmic catalytic domain which is related to bacterial alanine racemases. To gain insight into the molecular function of VanT, the crystal structure of the catalytic domain of VanTG from VanG-type resistant Enterococcus faecalis BM4518 wasmore » determined. The structure showed significant similarity to type III pyridoxal 5'-phosphate (PLP)-dependent alanine racemases, which are essential for peptidoglycan synthesis. Comparative structural analysis between VanTG and alanine racemases as well as site-directed mutagenesis identified three specific active site positions centered around Asn696 which are responsible for theL-amino acid specificity. This analysis also suggested that VanT racemases evolved from regular alanine racemases by acquiring additional selectivity toward serine while preserving that for alanine. The 4-fold-lower relative catalytic efficiency of VanTG against L-Ser versus L-Ala implied that this enzyme relies on its membrane-bound domain for L-Ser transport to increase the overall rate of D-Ser production. These findings illustrate how vancomycin pressure selected for molecular adaptation of a housekeeping enzyme to a bifunctional enzyme to allow for peptidoglycan remodeling, a strategy increasingly observed in antibiotic-resistant bacteria.« less

  5. Comments by Julie Crenshaw Van Fleet on DOE/SEA-04, Special Environmental

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

    Analysis: For Actions Taken Under U.S. Department of Energy Emergency Orders Regarding Operation of the Potomac River Generating Station in Alexandria, Virginia, November 2006 | Department of Energy Julie Crenshaw Van Fleet on DOE/SEA-04, Special Environmental Analysis: For Actions Taken Under U.S. Department of Energy Emergency Orders Regarding Operation of the Potomac River Generating Station in Alexandria, Virginia, November 2006 Comments by Julie Crenshaw Van Fleet on DOE/SEA-04, Special

  6. Tuning the electronic structure of monolayer graphene/ Mo S 2...

    Office of Scientific and Technical Information (OSTI)

    Tuning the electronic structure of monolayer graphene Mo S 2 van der Waals ... Title: Tuning the electronic structure of monolayer graphene Mo S 2 van der Waals ...

  7. van der Waals forces and confinement in carbon nanopores: Interaction between CH4, COOH, NH3, OH, SH and single-walled carbon nanotubes

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

    Weck, Philippe F.; Kim, Eunja; Wang, Yifeng

    2016-04-13

    Interactions between CH4, COOH, NH3, OH, SH and armchair (n,n)(n=4,7,14) and zigzag (n,0)(n=7,12,25) single-walled carbon nanotubes (SWCNTs) have been systematically investigated within the framework of dispersion-corrected density functional theory (DFT-D2). Endohedral and exohedral molecular adsorption on SWCNT walls is energetically unfavorable or weak, despite the use of C6/r6 pairwise London-dispersion corrections. The effects of pore size and chirality on the molecule/SWCNTs interaction were also assessed. Furthermore, chemisorption of COOH, NH3, OH and SH at SWCNT edge sites was examined using a H-capped (7,0) SWCNT fragment and its impact on electrophilic, nucleophilic and radical attacks was predicted by means of Fukuimore » functions.« less

  8. Atomic radii for atoms with the 6s shell outermost: The effective atomic radius and the van der Waals radius from {sub 55}Cs to {sub 80}Hg

    SciTech Connect (OSTI)

    Tatewaki, Hiroshi; Hatano, Yasuyo; Noro, Takeshi; Yamamoto, Shigeyoshi

    2015-06-15

    We consider, for atoms from {sub 55}Cs to {sub 80}Hg, the effective atomic radius (r{sub ear}), which is defined as the distance from the nucleus at which the magnitude of the electric field is equal to that in He at one half of the equilibrium bond length of He{sub 2}. The values of r{sub ear} are about 50% larger than the mean radius of the outermost occupied orbital of 6s, . The value of r{sub ear} decreases from {sub 55}Cs to {sub 56}Ba and undergoes increases and decreases with rising nuclear charge from {sub 57}La to {sub 70}Y b. In fact r{sub ear} is understood as comprising two interlaced sequences; one consists of {sub 57}La, {sub 58}Ce, and {sub 64}Gd, which have electronic configuration (4f{sup n−1})(5d{sup 1})(6s{sup 2}), and the remaining atoms have configuration (4f{sup n})(6s{sup 2}). The sphere defined by r{sub ear} contains 85%–90% of the 6s electrons. From {sub 71}Lu to {sub 80}Hg the radius r{sub ear} also involves two sequences, corresponding to the two configurations 5d{sup n+1}6s{sup 1} and 5d{sup n}6s{sup 2}. The radius r{sub ear} according to the present methodology is considerably larger than r{sub vdW} obtained by other investigators, some of who have found values of r{sub vdW} close to .

  9. Laboratory tests of IEC DER object models for grid applications.

    SciTech Connect (OSTI)

    Blevins, John D.; Menicucci, David F.; Byrd, Thomas, Jr.; Gonzalez, Sigifredo; Ginn, Jerry W.; Ortiz-Moyet, Juan

    2007-02-01

    This report describes a Cooperative Research and Development Agreement (CRADA) between Salt River Project Agricultural Improvement and Power District (SRP) and Sandia National Laboratories to jointly develop advanced methods of controlling distributed energy resources (DERs) that may be located within SRP distribution systems. The controls must provide a standardized interface to allow plug-and-play capability and should allow utilities to take advantage of advanced capabilities of DERs to provide a value beyond offsetting load power. To do this, Sandia and SRP field-tested the IEC 61850-7-420 DER object model (OM) in a grid environment, with the goal of validating whether the model is robust enough to be used in common utility applications. The diesel generator OM tested was successfully used to accomplish basic genset control and monitoring. However, as presently constituted it does not enable plug-and-play functionality. Suggestions are made of aspects of the standard that need further development and testing. These problems are far from insurmountable and do not imply anything fundamentally unsound or unworkable in the standard.

  10. DOE - Office of Legacy Management -- John Van Range Co Div of Edwards

    Office of Legacy Management (LM)

    Manufacturing - OH 40 John Van Range Co Div of Edwards Manufacturing - OH 40 FUSRAP Considered Sites Site: JOHN VAN RANGE CO., DIV. OF EDWARDS MANUFACTURING (OH.40 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Cincinnati , Ohio OH.40-1 Evaluation Year: 1994 OH.40-2 OH.40-3 Site Operations: Punched washers from uranium metal slabs in the mid-1950s. OH.40-1 Site Disposition: Eliminated - Potential for contamination remote based on

  11. Comparison of Different Load Road Implementation Strategies on Fuel Economy of USPS Step Vans

    Broader source: Energy.gov [DOE]

    An alternative form of measuring road loads, instead of using a chassis dynamometer and a method described in 40 CFR section 86.1229-85, was conducted on on-road coastdowns, and regression analysis was used to determine the characteristics of the two U.S. Postal Service step vans, one of which was a hybrid model

  12. Flexible DER Utility Interface System: Final Report, September 2004--May 2006

    SciTech Connect (OSTI)

    Lynch, J.; John, V.; Danial, S. M.; Benedict, E.; Vihinen, I.; Kroposki, B.; Pink, C.

    2006-08-01

    In an effort to accelerate deployment of Distributed Energy Resources (DER) such as wind, solar, and conventional backup generators to our nation's electrical grid, Northern Power Systems (NPS), the California Energy Commission (CEC), and the National Renewable Energy Laboratory (NREL) collaborated to create a prototype universal interconnect device called the DER Switch.

  13. Ford Van Dyke: Compressed Air Management Program Leads to Improvements that Reduce Energy Consumption at an Automotive Transmission Plant

    SciTech Connect (OSTI)

    2010-06-25

    Staff at the Ford Van Dyke Transmission Plant in Sterling Heights, Michigan, have increased the efficiency of the plant’s compressed air system to enhance its performance while saving energy and improving production.

  14. FTP Emissions Test Results from Flexible-Fuel Methanol Dodge Spirits and Ford Econoline Vans

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    FTP Emissions Test Results from Flexible-Fuel Methanol Dodge Spirits and Ford Econoline Vans Kenneth J. Kelly, Brent K. Bailey, and Timothy C. Coburn National Renewable Energy Laboratory Wendy Clark Automotive Testing Laboratories, Inc. Leslie Eudy ManTech Environmental Technology, Inc. Peter Lissiuk Environmental Research and Development Corp. Presented at Society for Automotive Engineers International Spring Fuels and Lubricants Meeting Dearborn, MI May 6-8, 1996 The work described here was

  15. Data Assimilation J. S. Van Baelen(a) National Center for Atmospheric Research(b)

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

    S. Van Baelen(a) National Center for Atmospheric Research(b) Boulder, CO 80307-3000 Introduction of wind profilers to provide accurate estimates of the momentum and heat fluxes might be their most important contribution yet to the field of atmospheric dynamic studies, especially when those measurements can be ingested into circulation models. In particular, flux measurements in the planetary boundary layer can provide critically needed information on the pel turbulent structures and their effect

  16. A polynomial approach to the van Everdingen-Hurst dimensionless variables for water encroachment

    SciTech Connect (OSTI)

    Klins, M.A.; Bouchard, A.J.; Cable, C.L.

    1988-02-01

    Traditional water-influx calculations rely on accurate values of the van Everdingen and Hurst dimensionless variables rho/sub D/ and q/sub D/. The authors presented six sets of simple polynomials that provide a fast, simple method to determine rho/sub D/, rho/sub D'/, and q/sub D/ for finite or infinite radial aquifers. The results yield values as accurate as the original tables and are up to 15 times more efficient.

  17. Eighteen-Month Final Evaluation of UPS Second Generation Diesel Hybrid-Electric Delivery Vans

    SciTech Connect (OSTI)

    Lammert, M.; Walkowicz, K.

    2012-09-01

    A parallel hybrid-electric diesel delivery van propulsion system was evaluated at a UPS facility in Minneapolis using on-vehicle data logging, fueling, and maintenance records. Route and drive cycle analysis showed different duty cycles for hybrid vs. conventional delivery vans; routes were switched between the study groups to provide a valid comparison. The hybrids demonstrated greater advantage on the more urban routes; the initial conventional vans' routes had less dense delivery zones. The fuel economy of the hybrids on the original conventional group?s routes was 10.4 mpg vs. 9.2 mpg for the conventional group on those routes a year earlier. The hybrid group's fuel economy on the original hybrid route assignments was 9.4 mpg vs. 7.9 mpg for the conventional group on those routes a year later. There was no statistically significant difference in total maintenance cost per mile or for the vehicle total cost of operation per mile. Propulsion-related maintenance cost per mile was 77% higher for the hybrids, but only 52% more on a cost-per-delivery-day basis. Laboratory dynamometer testing demonstrated 13%-36% hybrid fuel economy improvement, depending on duty cycle, and up to a 45% improvement in ton-mi/gal. NOx emissions increased 21%-49% for the hybrids in laboratory testing.

  18. Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes

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

    Sarno-Smith, Lois K.; Larsen, Brian A.; Skoug, Ruth M.; Liemohn, Michael W.; Breneman, Aaron; Wygant, John R.; Thomsen, Michelle F.

    2016-02-27

    Using the Helium Oxygen Proton Electron (HOPE) and Electric Field and Waves (EFW) instruments from the Van Allen Probes, we explored the relationship between electron energy fluxes in the eV and keV ranges and spacecraft surface charging. We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT. An algorithm to extract the H+ charging line in the HOPE instrument data was developed to better explore intense charging events. Also, this study explored how spacecraft potential relates to electron number density, electron pressure, electron temperature, thermal electron current, and low-energy ion density between 1 and 210 eV.more » It is demonstrated that it is imperative to use both EFW potential measurements and the HOPE instrument ion charging line for examining times of extreme spacecraft charging of the Van Allen Probes. The results of this study show that elevated electron energy fluxes and high-electron pressures are present during times of spacecraft charging but these same conditions may also occur during noncharging times. Furthermore, we also show noneclipse significant negative charging events on the Van Allen Probes.« less

  19. Optimizing Distributed Energy Resources and building retrofits with the strategic DER-CAModel

    SciTech Connect (OSTI)

    Stadler, M.; Groissböck, M.; Cardoso, G.; Marnay, C.

    2014-08-05

    The pressuring need to reduce the import of fossil fuels as well as the need to dramatically reduce CO2 emissions in Europe motivated the European Commission (EC) to implement several regulations directed to building owners. Most of these regulations focus on increasing the number of energy efficient buildings, both new and retrofitted, since retrofits play an important role in energy efficiency. Overall, this initiative results from the realization that buildings will have a significant impact in fulfilling the 20/20/20-goals of reducing the greenhouse gas emissions by 20%, increasing energy efficiency by 20%, and increasing the share of renewables to 20%, all by 2020. The Distributed Energy Resources Customer Adoption Model (DER-CAM) is an optimization tool used to support DER investment decisions, typically by minimizing total annual costs or CO2 emissions while providing energy services to a given building or microgrid site. This document shows enhancements made to DER-CAM to consider building retrofit measures along with DER investment options. Specifically, building shell improvement options have been added to DER-CAM as alternative or complementary options to investments in other DER such as PV, solar thermal, combined heat and power, or energy storage. The extension of the mathematical formulation required by the new features introduced in DER-CAM is presented and the resulting model is demonstrated at an Austrian Campus building by comparing DER-CAM results with and without building shell improvement options. Strategic investment results are presented and compared to the observed investment decision at the test site. Results obtained considering building shell improvement options suggest an optimal weighted average U value of about 0.53 W/(m2K) for the test site. This result is approximately 25% higher than what is currently observed in the building, suggesting that the retrofits made in 2002 were not optimal. Furthermore

  20. Optimizing Distributed Energy Resources and building retrofits with the strategic DER-CAModel

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

    Stadler, M.; Groissböck, M.; Cardoso, G.; Marnay, C.

    2014-08-05

    The pressuring need to reduce the import of fossil fuels as well as the need to dramatically reduce CO2 emissions in Europe motivated the European Commission (EC) to implement several regulations directed to building owners. Most of these regulations focus on increasing the number of energy efficient buildings, both new and retrofitted, since retrofits play an important role in energy efficiency. Overall, this initiative results from the realization that buildings will have a significant impact in fulfilling the 20/20/20-goals of reducing the greenhouse gas emissions by 20%, increasing energy efficiency by 20%, and increasing the share of renewables to 20%,more » all by 2020. The Distributed Energy Resources Customer Adoption Model (DER-CAM) is an optimization tool used to support DER investment decisions, typically by minimizing total annual costs or CO2 emissions while providing energy services to a given building or microgrid site. This document shows enhancements made to DER-CAM to consider building retrofit measures along with DER investment options. Specifically, building shell improvement options have been added to DER-CAM as alternative or complementary options to investments in other DER such as PV, solar thermal, combined heat and power, or energy storage. The extension of the mathematical formulation required by the new features introduced in DER-CAM is presented and the resulting model is demonstrated at an Austrian Campus building by comparing DER-CAM results with and without building shell improvement options. Strategic investment results are presented and compared to the observed investment decision at the test site. Results obtained considering building shell improvement options suggest an optimal weighted average U value of about 0.53 W/(m2K) for the test site. This result is approximately 25% higher than what is currently observed in the building, suggesting that the retrofits made in 2002 were not optimal. Furthermore, the results obtained with

  1. 3rd Annual National CHP Roadmap Workshop CHP and DER for Federal Facilities

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

    EPA CHP Partnership Meeting, October 2002 | Department of Energy 3rd Annual National CHP Roadmap Workshop CHP and DER for Federal Facilities EPA CHP Partnership Meeting, October 2002 3rd Annual National CHP Roadmap Workshop CHP and DER for Federal Facilities EPA CHP Partnership Meeting, October 2002 This is an announcement of the 3rd Annual National CHP Roadmap Workshop which was held in conjunction with the CHP and Distributed Energy Resources for Federal Facilities Workshop, October 23-25,

  2. Thirty-Six Month Evaluation of UPS Diesel Hybrid Electric Delivery Vans

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

    Thirty-Six Month Evaluation of UPS Diesel Hybrid-Electric Delivery Vans M. Lammert and K. Walkowicz Technical Report NREL/TP-5400-53503 March 2012 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Thirty-Six Month Evaluation of UPS Diesel

  3. PROJECT PROFILE: CyDER: A Cyber Physical Co-simulation Platform for

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

    Distributed Energy Resources in Smart Grids (SuNLaMP) | Department of Energy PROJECT PROFILE: CyDER: A Cyber Physical Co-simulation Platform for Distributed Energy Resources in Smart Grids (SuNLaMP) PROJECT PROFILE: CyDER: A Cyber Physical Co-simulation Platform for Distributed Energy Resources in Smart Grids (SuNLaMP) Funding Program: SuNLaMP SunShot Subprogram: Systems Integration Location: Lawrence Berkeley National Laboratory, Berkeley, CA SunShot Award Amount: $4,000,000 This project

  4. High-field de Haas{endash}van Alphen measurements in Pd

    SciTech Connect (OSTI)

    Vuillemin, J.J. [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)] [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Harrison, N. [National High Magnetic Field Laboratory, Los Alamos National Laboratory, LANL, Los Alamos, New Mexico 87545 (United States)] [National High Magnetic Field Laboratory, Los Alamos National Laboratory, LANL, Los Alamos, New Mexico 87545 (United States); Goodrich, R.G. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)] [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

    1999-05-01

    The de Haas{endash}van Alphen (dHvA) effect in 99.999{percent} pure palladium has been observed in pulsed fields up to 60 T directed along [100]. We report a dHvA frequency of 73.5 kT with a cyclotron effective mass=12.5m{sub 0}. Such a frequency is not reported previously but is predicted by band theory for the open hole sheet of the Fermi surface. We also observe strong harmonic content near 50 T for the electron sheet and this is interpreted in terms of a field-dependent {ital g} factor. {copyright} {ital 1999} {ital The American Physical Society}

  5. The gene for the Ellis-van Creveld syndrome is located on chromosome 4p16

    SciTech Connect (OSTI)

    Polymeropoulos, M.H.; Ide, S.E.; Wright, M.

    1996-07-01

    Ellis-van Creveld syndrome (EVC) is an autosomal recessive disorder characterized by disproportionate dwarfism, polydactyly, and congenital heart disease. This rare disorder is found with increased frequency among the Old Order Amish community in Lancaster County, Pennsylvania. We have used linkage analysis to localize the gene responsible for the EVC phenotype in nine interrelated Amish pedigrees and three unrelated families from Mexico, Ecuador, and Brazil. We now report the linkage for the Ellisvan Creveld syndrome gene to markers on the distal short arm of human chromosome 4, with Z{sub max} = 6.91 at {theta} = 0.02 for marker HOX7, in a region proximal to the FGFR3 gene responsible for the achondroplasia phenotype. 17 refs., 2 figs., 1 tab.

  6. Wave-driven butterfly distribution of Van Allen belt relativistic electrons

    SciTech Connect (OSTI)

    Xiao, Fuliang; Yang, Chang; Su, Zhenpeng; Zhou, Qinghua; He, Zhaoguo; He, Yihua; Baker, D. N.; Spence, H. E.; Funsten, H. O.; Blake, J. B.

    2015-10-05

    Van Allen radiation belts consist of relativistic electrons trapped by Earth's magnetic field. Trapped electrons often drift azimuthally around Earth and display a butterfly pitch angle distribution of a minimum at 90° further out than geostationary orbit. This is usually attributed to drift shell splitting resulting from day–night asymmetry in Earth’s magnetic field. However, direct observation of a butterfly distribution well inside of geostationary orbit and the origin of this phenomenon have not been provided so far. Here we report high-resolution observation that a unusual butterfly pitch angle distribution of relativistic electrons occurred within 5 Earth radii during the 28 June 2013 geomagnetic storm. In conclusion, simulation results show that combined acceleration by chorus and magnetosonic waves can successfully explain the electron flux evolution both in the energy and butterfly pitch angle distribution. Finally, the current provides a great support for the mechanism of wave-driven butterfly distribution of relativistic electrons.

  7. Advanced Vehicle Testing Activity: Dodge Ram Wagon Van - Hydrogen/CNG Operations Summary - January 2003

    SciTech Connect (OSTI)

    Karner, D.; Francfort, J.E.

    2003-01-16

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy's Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle, a Dodge Ram Wagon Van, operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to run CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service's Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of 22,816 miles of testing for the Dodge Ram Wagon Van, operating on CNG fuel, and a blended fuel of 15% hydrogen-85% CNG.

  8. Advanced Vehicle Testing Activity: Dodge Ram Wagon Van -- Hydrogen/CNG Operations Summary

    SciTech Connect (OSTI)

    Don Karner; Francfort, James Edward

    2003-01-01

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy’s Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle, a Dodge Ram Wagon Van, operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to run CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service’s Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of 22,816 miles of testing for the Dodge Ram Wagon Van, operating on CNG fuel, and a blended fuel of 15% hydrogen–85% CNG.

  9. Connecting Distributed Energy Resources to the Grid: Their Benefits to the DER Owner etc.

    SciTech Connect (OSTI)

    Poore, WP

    2003-07-09

    The vision of the Distributed Energy Research Program (DER) program of the U.S. Department of Energy (DOE) is that the United States will have the cleanest and most efficient and reliable energy system in the world by maximizing the use of affordable distributed energy resources. Electricity consumers will be able to choose from a diverse number of efficient, cost-effective, and environmentally friendly distributed energy options and easily connect them into the nation's energy infrastructure while providing benefits to their owners and other stakeholders. The long-term goal of this vision is that DER will achieve a 20% share of new electric capacity additions in the United States by 2010, thereby helping to make the nation's electric power generation and delivery system more efficient, reliable, secure, clean, economical, and diverse in terms of fuel use (oil, natural gas, solar, hydroelectric, etc.) and prime mover resource (solar, wind, gas turbines, etc.). Near- and mid-term goals are to develop new technologies for implementing and operating DER and address barriers associated with DER usage and then to reduce costs and emissions and improve the efficiency and reliability of DER. Numerous strategies for meeting these goals have been developed into a research, development, and demonstration (RD&D) program that supports generation and delivery systems architecture, including modeling and simulation tools. The benefits associated with DER installations are often significant and numerous. They almost always provide tangible economic benefits, such as energy savings or transmission and distribution upgrade deferrals, as well as intangible benefits, such as power quality improvements that lengthen maintenance or repair intervals for power equipment. Also, the benefits routinely are dispersed among end users, utilities, and the public. For instance, an end user may use the DER to reduce their peak demand and save money due to lower demand charges. Reduced end user

  10. Browse by Discipline -- E-print Network Subject Pathways: Energy...

    Office of Scientific and Technical Information (OSTI)

    Quantum Electron Matter Group, Van der Waals-Zeeman Institute for Experimental Physics, Universiteit van Amsterdam Queensland, University of - Department of Physics, Laser ...

  11. Assessment of (mu)grid distributed energy resource potential using DER-CAM and GIS

    SciTech Connect (OSTI)

    Edwards, Jennifer L.; Marnay, Chris; Bartholomew, Emily; Ouaglal, Boubekeur; Siddiqui, Afzal S.; LaCommare, Kristina S.H.

    2002-01-01

    This report outlines an approach to assess the local potential for deployment of distributed energy resources (DER), small power-generation installations located close to the point where the energy they produce will be consumed. Although local restraints, such as zoning, building codes, and on-site physical barriers are well-known frustrations to DER deployment, no analysis method has been developed to address them within a broad economic analysis framework. The approach developed here combines established economic optimization techniques embedded in the Distributed Energy Resource Customer Adoption Model (DER-CAM) with a geographic information system (GIS) analysis of local land-use constraint. An example case in the San Diego area is developed from a strictly customer perspective, based on the premise that future development of DER may take the form of microgrids ((mu)Grids) under the control of current utility customers. Beginning with assumptions about which customer combinations h ave complementary energy loads, a GIS was used to locate specific neighborhoods in the San Diego area with promising customer combinations. A detailed energy analysis was conducted for the commercial/residential area chosen covering both electrical and heat energy requirements. Under various scenarios, different combinations of natural gas reciprocating engines were chosen by DER-CAM, ranging in size from 25 kW to 500 kW, often with heat recovery or absorption cooling. These generators typically operate throughout the day and are supplemented by purchased electricity during late-night and early-morning hours, when utility time-of-use prices are lowest. Typical (mu)Grid scenarios displaced about 80 percent of their annual gas heat load through CHP. Self-generation together with absorption cooling dramatically reduce electricity purchases, which usually only occur during nighttime hours.

  12. Round 1 Emissions Results from Compressed Natural Gas Vans and Gasoline Controls Operating in the U.S. Federal Fleet

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Round 1 Emissions Results from Compressed Natural Gas Vans and Gasoline Controls Operating in the U.S. Federal Fleet Kenneth J. Kelly, Brent K. Bailey, and Timothy C. Coburn National Renewable Energy Laboratory Leslie Eudy ManTech Environmental Technology, Inc. Peter Lissiuk Environmental Research and Development Corp. Presented at Society for Automotive Engineers International Spring Fuels and Lubricants Meeting Dearborn, MI May 6-8, 1996 The work described here was wholly funded by the U.S.

  13. Project Overview: United Parcel Service's Second-Generation Hybrid-Electric Delivery Vans (Fact Sheet), Vehicle Technologies Program (VTP)

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

    eere.energy.gov * November 2011 UPS operates 381 hybrid-electric delivery vans nationwide. This image is reproduced with permission of United Parcel Service of America, Inc. © 2011 United Parcel Service of America, Inc. All rights reserved. Photo from UPS, NREL/PIX 19821 Advanced Vehicle Testing This project is part of a series of evaluations performed by NREL's Fleet Test and Evaluation Team for the U.S. Department of Energy's Advanced Vehicle Testing Activity (AVTA). AVTA bridges the gap

  14. The Global Positioning System constellation as a space weather monitor. Comparison of electron measurements with Van Allen Probes data

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

    Morley, Steven K.; Sullivan, John P.; Henderson, Michael G.; Blake, J. Bernard; Baker, Daniel N.

    2016-02-06

    Energetic electron observations in Earth's radiation belts are typically sparse, and multipoint studies often rely on serendipitous conjunctions. This paper establishes the scientific utility of the Combined X-ray Dosimeter (CXD), currently flown on 19 satellites in the Global Positioning System (GPS) constellation, by cross-calibrating energetic electron measurements against data from the Van Allen Probes. By breaking our cross calibration into two parts—one that removes any spectral assumptions from the CXD flux calculation and one that compares the energy spectra—we first validate the modeled instrument response functions, then the calculated electron fluxes. Unlike previous forward modeling of energetic electron spectra, wemore » use a combination of four distributions that together capture a wide range of observed spectral shapes. Moreover, our two-step approach allowed us to identify, and correct for, small systematic offsets between block IIR and IIF satellites. Using the Magnetic Electron Ion Spectrometer and Relativistic Electron-Proton Telescope on Van Allen Probes as a “gold standard,” here we demonstrate that the CXD instruments are well understood. A robust statistical analysis shows that CXD and Van Allen Probes fluxes are similar and the measured fluxes from CXD are typically within a factor of 2 of Van Allen Probes at energies inline image4 MeV. Our team present data from 17 CXD-equipped GPS satellites covering the 2015 “St. Patrick's Day” geomagnetic storm to illustrate the scientific applications of such a high data density satellite constellation and therefore demonstrate that the GPS constellation is positioned to enable new insights in inner magnetospheric physics and space weather forecasting.« less

  15. A long-lived relativistic electron storage ring embedded in Earth's Outer Van Allen belt

    SciTech Connect (OSTI)

    Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; Henderson, M. G.; Li, X.; Spence, H. E.; Elkington, S. R.; Friedel, R. H. W.; Goldstein, J.; Hudson, M. K.; Reeves, G. D.; Thorne, R. M.; Kletzing, C. A.; Claudepierre, S. G.

    2013-02-28

    Since their discovery over 50 years ago, the Earth’s Van Allen radiation belts are thought to consist of two distinct zones of trapped, highly energetic charged particles. The outer zone is comprised predominantly of mega-electron volt (MeV) electrons that wax and wane in intensity on time scales ranging from hours to days depending primarily on external forcing by the solar wind. Thus, the spatially separated inner zone is comprised of commingled high-energy electrons and very energetic positive ions (mostly protons), the latter being stable in intensity levels over years to decades. In situ energy-specific and temporally resolved spacecraft observations reveal an isolated third ring, or torus, of high-energy (E > 2 MeV) electrons that formed on 2 September 2012 and persisted largely unchanged in the geocentric radial range of 3.0 to ~3.5 Earth radii for over four weeks before being disrupted (and virtually annihilated) by a powerful interplanetary shock wave passage.

  16. Wave-driven butterfly distribution of Van Allen belt relativistic electrons

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

    Xiao, Fuliang; Yang, Chang; Su, Zhenpeng; Zhou, Qinghua; He, Zhaoguo; He, Yihua; Baker, D. N.; Spence, H. E.; Funsten, H. O.; Blake, J. B.

    2015-10-05

    Van Allen radiation belts consist of relativistic electrons trapped by Earth's magnetic field. Trapped electrons often drift azimuthally around Earth and display a butterfly pitch angle distribution of a minimum at 90° further out than geostationary orbit. This is usually attributed to drift shell splitting resulting from day–night asymmetry in Earth’s magnetic field. However, direct observation of a butterfly distribution well inside of geostationary orbit and the origin of this phenomenon have not been provided so far. Here we report high-resolution observation that a unusual butterfly pitch angle distribution of relativistic electrons occurred within 5 Earth radii during the 28more » June 2013 geomagnetic storm. In conclusion, simulation results show that combined acceleration by chorus and magnetosonic waves can successfully explain the electron flux evolution both in the energy and butterfly pitch angle distribution. Finally, the current provides a great support for the mechanism of wave-driven butterfly distribution of relativistic electrons.« less

  17. A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

    SciTech Connect (OSTI)

    Claudepierre, S. G.; O'Brien, T. P.; Blake, J. B.; Fennell, J. F.; Roeder, J. L.; Clemmons, J. H.; Looper, M. D.; Mazur, J. E.; Mulligan, T. M.; Spence, H. E.; Reeves, G. D.; Friedel, R. H. W.; Henderson, M. G.; Larsen, B. A.

    2015-07-14

    We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30–500 keV) and in regions of geospace where multi-M eV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background-corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

  18. A long-lived relativistic electron storage ring embedded in Earth's Outer Van Allen belt

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

    Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; Henderson, M. G.; Li, X.; Spence, H. E.; Elkington, S. R.; Friedel, R. H. W.; Goldstein, J.; Hudson, M. K.; et al

    2013-02-28

    Since their discovery over 50 years ago, the Earth’s Van Allen radiation belts are thought to consist of two distinct zones of trapped, highly energetic charged particles. The outer zone is comprised predominantly of mega-electron volt (MeV) electrons that wax and wane in intensity on time scales ranging from hours to days depending primarily on external forcing by the solar wind. Thus, the spatially separated inner zone is comprised of commingled high-energy electrons and very energetic positive ions (mostly protons), the latter being stable in intensity levels over years to decades. In situ energy-specific and temporally resolved spacecraft observations revealmore » an isolated third ring, or torus, of high-energy (E > 2 MeV) electrons that formed on 2 September 2012 and persisted largely unchanged in the geocentric radial range of 3.0 to ~3.5 Earth radii for over four weeks before being disrupted (and virtually annihilated) by a powerful interplanetary shock wave passage.« less

  19. A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

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

    Claudepierre, S. G.; O'Brien, T. P.; Blake, J. B.; Fennell, J. F.; Roeder, J. L.; Clemmons, J. H.; Looper, M. D.; Mazur, J. E.; Mulligan, T. M.; Spence, H. E.; et al

    2015-07-14

    We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30–500 keV) and in regions of geospace where multi-M eV electrons are present. Inner zone protons produce contamination in all MagEIS energymore » channels at roughly L < 2.5. The background-corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).« less

  20. U-152: OpenSSL "asn1_d2i_read_bio()" DER Format Data Processing Vulnerability

    Broader source: Energy.gov [DOE]

    The vulnerability is caused due to a type casting error in the "asn1_d2i_read_bio()" function when processing DER format data and can be exploited to cause a heap-based buffer overflow.

  1. Density functional theory study of the interaction of vinyl radical, ethyne, and ethene with benzene, aimed to define an affordable computational level to investigate stability trends in large van der Waals complexes

    SciTech Connect (OSTI)

    Maranzana, Andrea E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it Giordana, Anna E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it Indarto, Antonius Tonachini, Glauco; Barone, Vincenzo E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it; Causà, Mauro E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it; Pavone, Michele E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it

    2013-12-28

    Our purpose is to identify a computational level sufficiently dependable and affordable to assess trends in the interaction of a variety of radical or closed shell unsaturated hydro-carbons A adsorbed on soot platelet models B. These systems, of environmental interest, would unavoidably have rather large sizes, thus prompting to explore in this paper the performances of relatively low-level computational methods and compare them with higher-level reference results. To this end, the interaction of three complexes between non-polar species, vinyl radical, ethyne, or ethene (A) with benzene (B) is studied, since these species, involved themselves in growth processes of polycyclic aromatic hydrocarbons (PAHs) and soot particles, are small enough to allow high-level reference calculations of the interaction energy ΔE{sub AB}. Counterpoise-corrected interaction energies ΔE{sub AB} are used at all stages. (1) Density Functional Theory (DFT) unconstrained optimizations of the A−B complexes are carried out, using the B3LYP-D, ωB97X-D, and M06-2X functionals, with six basis sets: 6-31G(d), 6-311 (2d,p), and 6-311++G(3df,3pd); aug-cc-pVDZ and aug-cc-pVTZ; N07T. (2) Then, unconstrained optimizations by Møller-Plesset second order Perturbation Theory (MP2), with each basis set, allow subsequent single point Coupled Cluster Singles Doubles and perturbative estimate of the Triples energy computations with the same basis sets [CCSD(T)//MP2]. (3) Based on an additivity assumption of (i) the estimated MP2 energy at the complete basis set limit [E{sub MP2/CBS}] and (ii) the higher-order correlation energy effects in passing from MP2 to CCSD(T) at the aug-cc-pVTZ basis set, ΔE{sub CC-MP}, a CCSD(T)/CBS estimate is obtained and taken as a computational energy reference. At DFT, variations in ΔE{sub AB} with basis set are not large for the title molecules, and the three functionals perform rather satisfactorily even with rather small basis sets [6-31G(d) and N07T], exhibiting deviation from the computational reference of less than 1 kcal mol{sup −1}. The zero-point vibrational energy corrected estimates Δ(E{sub AB}+ZPE), obtained with the three functionals and the 6-31G(d) and N07T basis sets, are compared with experimental D{sub 0} measures, when available. In particular, this comparison is finally extended to the naphthalene and coronene dimers and to three π−π associations of different PAHs (R, made by 10, 16, or 24 C atoms) and P (80 C atoms)

  2. Experimental validation of the van Herk margin formula for lung radiation therapy

    SciTech Connect (OSTI)

    Ecclestone, Gillian; Heath, Emily; Bissonnette, Jean-Pierre

    2013-11-15

    Purpose: To validate the van Herk margin formula for lung radiation therapy using realistic dose calculation algorithms and respiratory motion modeling. The robustness of the margin formula against variations in lesion size, peak-to-peak motion amplitude, tissue density, treatment technique, and plan conformity was assessed, along with the margin formula assumption of a homogeneous dose distribution with perfect plan conformity.Methods: 3DCRT and IMRT lung treatment plans were generated within the ORBIT treatment planning platform (RaySearch Laboratories, Sweden) on 4DCT datasets of virtual phantoms. Random and systematic respiratory motion induced errors were simulated using deformable registration and dose accumulation tools available within ORBIT for simulated cases of varying lesion sizes, peak-to-peak motion amplitudes, tissue densities, and plan conformities. A detailed comparison between the margin formula dose profile model, the planned dose profiles, and penumbra widths was also conducted to test the assumptions of the margin formula. Finally, a correction to account for imperfect plan conformity was tested as well as a novel application of the margin formula that accounts for the patient-specific motion trajectory.Results: The van Herk margin formula ensured full clinical target volume coverage for all 3DCRT and IMRT plans of all conformities with the exception of small lesions in soft tissue. No dosimetric trends with respect to plan technique or lesion size were observed for the systematic and random error simulations. However, accumulated plans showed that plan conformity decreased with increasing tumor motion amplitude. When comparing dose profiles assumed in the margin formula model to the treatment plans, discrepancies in the low dose regions were observed for the random and systematic error simulations. However, the margin formula respected, in all experiments, the 95% dose coverage required for planning target volume (PTV) margin derivation, as

  3. Energetic electron precipitation associated with pulsating aurora: EISCAT and Van Allen Probe observations

    SciTech Connect (OSTI)

    Miyoshi, Y.; Oyama, S.; Saito, S.; Kurita, S.; Fujiwara, H.; Kataoka, R.; Ebihara, Y.; Kletzing, C.; Reeves, G.; Santolik, O.; Clilverd, M.; Rodger, C. J.; Turunen, E.; Tsuchiya, F.

    2015-04-21

    Pulsating auroras show quasi-periodic intensity modulations caused by the precipitation of energetic electrons of the order of tens of keV. It is expected theoretically that not only these electrons but also subrelativistic/relativistic electrons precipitate simultaneously into the ionosphere owing to whistler mode wave-particle interactions. The height-resolved electron density profile was observed with the European Incoherent Scatter (EISCAT) Tromsø VHF radar on 17 November 2012. Electron density enhancements were clearly identified at altitudes >68 km in association with the pulsating aurora, suggesting precipitation of electrons with a broadband energy range from ~10 keV up to at least 200 keV. The riometer and network of subionospheric radio wave observations also showed the energetic electron precipitations during this period. During this period, the footprint of the Van Allen Probe-A satellite was very close to Tromsø and the satellite observed rising tone emissions of the lower band chorus (LBC) waves near the equatorial plane. Considering the observed LBC waves and electrons, we conducted a computer simulation of the wave-particle interactions. This showed simultaneous precipitation of electrons at both tens of keV and a few hundred keV, which is consistent with the energy spectrum estimated by the inversion method using the EISCAT observations. This result revealed that electrons with a wide energy range simultaneously precipitate into the ionosphere in association with the pulsating aurora, providing the evidence that pulsating auroras are caused by whistler chorus waves. We suggest that scattering by propagating whistler simultaneously causes both the precipitations of subrelativistic electrons and the pulsating aurora.

  4. Advanced Vehicle Testing Activity: Hydrogen-Fueled Mercedes Sprinter Van -- Operating Summary

    SciTech Connect (OSTI)

    Karner, D.; Francfort, James Edward

    2003-01-01

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy's Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to run CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure- hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service's Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of testing conducted over 6,864 kilometers (4,265 miles) of operation using the pure-hydrogen-fueled Mercedes Sprinter van.

  5. Advanced Vehicle Testing Activity: Hydrogen-Fueled Mercedes Sprinter Van Operating Summary - January 2003

    SciTech Connect (OSTI)

    Karner, D.; Francfort, J.E.

    2003-01-22

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy's Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to run CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service's Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of testing conducted over 6,864 kilometers (4,265 miles) of operation using the pure-hydrogen-fueled Mercedes Sprinter van.

  6. Energetic electron precipitation associated with pulsating aurora: EISCAT and Van Allen Probe observations

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

    Miyoshi, Y.; Oyama, S.; Saito, S.; Kurita, S.; Fujiwara, H.; Kataoka, R.; Ebihara, Y.; Kletzing, C.; Reeves, G.; Santolik, O.; et al

    2015-04-21

    Pulsating auroras show quasi-periodic intensity modulations caused by the precipitation of energetic electrons of the order of tens of keV. It is expected theoretically that not only these electrons but also subrelativistic/relativistic electrons precipitate simultaneously into the ionosphere owing to whistler mode wave-particle interactions. The height-resolved electron density profile was observed with the European Incoherent Scatter (EISCAT) Tromsø VHF radar on 17 November 2012. Electron density enhancements were clearly identified at altitudes >68 km in association with the pulsating aurora, suggesting precipitation of electrons with a broadband energy range from ~10 keV up to at least 200 keV. The riometermore » and network of subionospheric radio wave observations also showed the energetic electron precipitations during this period. During this period, the footprint of the Van Allen Probe-A satellite was very close to Tromsø and the satellite observed rising tone emissions of the lower band chorus (LBC) waves near the equatorial plane. Considering the observed LBC waves and electrons, we conducted a computer simulation of the wave-particle interactions. This showed simultaneous precipitation of electrons at both tens of keV and a few hundred keV, which is consistent with the energy spectrum estimated by the inversion method using the EISCAT observations. This result revealed that electrons with a wide energy range simultaneously precipitate into the ionosphere in association with the pulsating aurora, providing the evidence that pulsating auroras are caused by whistler chorus waves. We suggest that scattering by propagating whistler simultaneously causes both the precipitations of subrelativistic electrons and the pulsating aurora.« less

  7. Van Allen Probes observation and modeling of chorus excitation and propagation during weak geomagnetic activities

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

    He, Yihua; Xiao, Fuliang; Zhou, Qinghua; Yang, Chang; Liu, Si; Baker, D. N.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; et al

    2015-08-20

    We report correlated data on nightside chorus waves and energetic electrons during two small storm periods: 1 November 2012 (Dst ≈ –45) and 14 January 2013 (Dst ≈ –18). The Van Allen Probes simultaneously observed strong chorus waves at locations L = 5.8 – 6.3, with a lower frequency band 0.1–0.5fce and a peak spectral density ~10–4 nT2/Hz. In the same period, the fluxes and anisotropy of energetic (~10–300 keV) electrons were greatly enhanced in the interval of large negative interplanetary magnetic field Bz. Using a bi-Maxwellian distribution to model the observed electron distribution, we perform ray tracing simulations tomore » show that nightside chorus waves are indeed produced by the observed electron distribution with a peak growth for a field-aligned propagation approximately between 0.3fce and 0.4fce, at latitude <7°. Moreover, chorus waves launched with initial normal angles either θ < 90° or > 90° propagate along the field either northward or southward and then bounce back either away from Earth for a lower frequency or toward Earth for higher frequencies. The current results indicate that nightside chorus waves can be excited even during weak geomagnetic activities in cases of continuous injection associated with negative Bz. Furthermore, we examine a dayside event during a small storm C on 8 May 2014 (Dst ≈ –45) and find that the observed anisotropic energetic electron distributions potentially contribute to the generation of dayside chorus waves, but this requires more thorough studies in the future.« less

  8. Van Allen Probes observation and modeling of chorus excitation and propagation during weak geomagnetic activities

    SciTech Connect (OSTI)

    He, Yihua; Xiao, Fuliang; Zhou, Qinghua; Yang, Chang; Liu, Si; Baker, D. N.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; Reeves, G. D.; Funsten, H. O.; Blake, J. B.

    2015-08-20

    We report correlated data on nightside chorus waves and energetic electrons during two small storm periods: 1 November 2012 (Dst ≈ –45) and 14 January 2013 (Dst ≈ –18). The Van Allen Probes simultaneously observed strong chorus waves at locations L = 5.8 – 6.3, with a lower frequency band 0.1–0.5fce and a peak spectral density ~10–4 nT2/Hz. In the same period, the fluxes and anisotropy of energetic (~10–300 keV) electrons were greatly enhanced in the interval of large negative interplanetary magnetic field Bz. Using a bi-Maxwellian distribution to model the observed electron distribution, we perform ray tracing simulations to show that nightside chorus waves are indeed produced by the observed electron distribution with a peak growth for a field-aligned propagation approximately between 0.3fce and 0.4fce, at latitude <7°. Moreover, chorus waves launched with initial normal angles either θ < 90° or > 90° propagate along the field either northward or southward and then bounce back either away from Earth for a lower frequency or toward Earth for higher frequencies. The current results indicate that nightside chorus waves can be excited even during weak geomagnetic activities in cases of continuous injection associated with negative Bz. Furthermore, we examine a dayside event during a small storm C on 8 May 2014 (Dst ≈ –45) and find that the observed anisotropic energetic electron distributions potentially contribute to the generation of dayside chorus waves, but this requires more thorough studies in the future.

  9. Van Allen Probes, THEMIS, GOES, and cluster observations of EMIC waves, ULF pulsations, and an electron flux dropout

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

    Sigsbee, K.; Kletzing, C. A.; Smith, C. W.; MacDowall, R.; Spence, H.; Reeves, G.; Blake, J. B.; Baker, D. N.; Green, J. C.; Singer, H. J.; et al

    2016-03-04

    We examined an electron flux dropout during the 12–14 November 2012 geomagnetic storm using observations from seven spacecraft: the two Van Allen Probes, Time History of Events and Macroscale Interactions during Substorms (THEMIS)-A (P5), Cluster 2, and Geostationary Operational Environmental Satellites (GOES) 13, 14, and 15. The electron fluxes for energies greater than 2.0 MeV observed by GOES 13, 14, and 15 at geosynchronous orbit and by the Van Allen Probes remained at or near instrumental background levels for more than 24 h from 12 to 14 November. For energies of 0.8 MeV, the GOES satellites observed two shorter intervalsmore » of reduced electron fluxes. The first interval of reduced 0.8 MeV electron fluxes on 12–13 November was associated with an interplanetary shock and a sudden impulse. Cluster, THEMIS, and GOES observed intense He+ electromagnetic ion cyclotron (EMIC) waves from just inside geosynchronous orbit out to the magnetopause across the dayside to the dusk flank. The second interval of reduced 0.8 MeV electron fluxes on 13–14 November was associated with a solar sector boundary crossing and development of a geomagnetic storm with Dst <–100 nT. At the start of the recovery phase, both the 0.8 and 2.0 MeV electron fluxes finally returned to near prestorm values, possibly in response to strong ultralow frequency (ULF) waves observed by the Van Allen Probes near dawn. A combination of adiabatic effects, losses to the magnetopause, scattering by EMIC waves, and acceleration by ULF waves can explain the observed electron behavior.« less

  10. TEMPERATURE MEASUREMENTS COLLECTED FROM AN INSTRUMENTED VAN IN SALT LAKE CITY, UTAH AS PART OF URBAN 2000

    SciTech Connect (OSTI)

    M.J. BROWN; E.R. PARDYJAK

    2001-08-01

    Measurements of temperature and position were collected during the night from an instrumented van on routes through Salt Lake City and the rural outskirts. The measurements were taken as part of the Department of Energy Chemical and Biological National Security Program URBAN 2 Field Experiment conducted in October 2000 (Shinn et al., 2000 and Allwine et al., 2001a). The instrumented van was driven over three primary routes, two including downtown, residential, and ''rural'' areas and a third that went by a line of permanently fixed temperature probes (Allwine et al., 2001b) for cross-checking purposes. Each route took from 45 to 60 minutes to complete. Based on four nights of data, initial analyses indicate that there was a temperature difference of 2-5 C between the urban core and nearby ''rural'' areas. Analyses also suggest that there were significant fine scale temperature differences over distances of tens of meters within the city and in the nearby rural areas. The temperature measurements that were collected are intended to supplement the meteorological measurements taken during the URBAN2000 Field Experiment, to assess the importance of the urban heat island phenomenon in Salt Lake City, and to test the urban canopy parameterizations that have been developed for regional scale meteorological codes as part of the DOE CBNP program.

  11. Combustion testing and heat recovery study: Frank E. Van Lare Wastewater Treatment Plant, Monroe County. Final report

    SciTech Connect (OSTI)

    1995-01-01

    The objectives of the study were to record and analyze sludge management operations data and sludge incinerator combustion data; ascertain instrumentation and control needs; calculate heat balances for the incineration system; and determine the feasibility of different waste-heat recovery technologies for the Frank E. Van Lare (FEV) Wastewater Treatment Plant. As an integral part of this study, current and pending federal and state regulations were evaluated to establish their impact on furnace operation and subsequent heat recovery. Of significance is the effect of the recently promulgated Federal 40 CFR Part 503 regulations on the FEV facility. Part 503 regulations were signed into law in November 1992, and, with some exceptions, affected facilities must be in compliance by February 19, 1994. Those facilities requiring modifications or upgrades to their incineration or air pollution control equipment to meet Part 503 regulations must be in compliance by February 19, 1995.

  12. The potential for distributed generation in Japanese prototype buildings: A DER-CAM analysis of policy, tariff design, building energy use, and technology development (Japanese translation)

    SciTech Connect (OSTI)

    Zhou, Nan; Marnay, Chris; Firestone, Ryan; Gao, Weijun; Nishida, Masaru

    2004-10-15

    The August 2003 blackout of the northeastern U.S. and CANADA caused great economic losses and inconvenience to New York City and other affected areas. The blackout was a warning to the rest of the world that the ability of conventional power systems to meet growing electricity demand is questionable. Failure of large power systems can lead to serious emergencies. Introduction of on-site generation, renewable energy such as solar and wind power and the effective utilization of exhaust heat is needed, to meet the growing energy demands of the residential and commercial sectors. Additional benefit can be achieved by integrating these distributed technologies into distributed energy resource (DER) systems. This work demonstrates a method for choosing and designing economically optimal DER systems. An additional purpose of this research is to establish a database of energy tariffs, DER technology cost and performance characteristics, and building energy consumption for Japan. This research builds on prior DER studies at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) and with their associates in the Consortium for Electric Reliability Technology Solutions (CERTS) and operation, including the development of the microgrid concept, and the DER selection optimization program, the Distributed Energy Resources Customer Adoption Model (DER-CAM). DER-CAM is a tool designed to find the optimal combination of installed equipment and an idealized operating schedule to minimize a site's energy bills, given performance and cost data on available DER technologies, utility tariffs, and site electrical and thermal loads over a test period, usually an historic year. Since hourly electric and thermal energy data are rarely available, they are typically developed by building simulation for each of six end use loads used to model the building: electric-only loads, space heating, space cooling, refrigeration, water heating, and natural-gas-only loads. DER-CAM provides a

  13. Distributed Energy Resources Customer Adoption Model (DER-CAM), Investment & Planing Version 3.10.5.m

    SciTech Connect (OSTI)

    2014-04-01

    Version 3.10.5 is a multi-year Decision Support tool for Distributed Generation (DG). DER-CAM was initially created as an exclusively economic energy model, able to find the cost minimizing combination and operation profile of a set of DER technologies that meet heat and electric loads of a single building or microgrid for a typical test year. Now, version 3.10.5.m solves for a multiple-year horizon the technology choice question, the appropriate capacity for each selected technology as well as the operational and investment schedule. Optimized investment decisions are based on techno-economic criteria, along with site information such as energy loads, economic forecast, and technology characterization. Version 3.10.5 contains: 1. a PV and battery degradation model and 2. variable performance for technologies. Efficiency, investment costs, etc. can vary over time and model technology breakthroughs and advancements.

  14. Distributed Energy Resources Customer Adoption Model (DER-CAM), Investment & Planing Version 3.10.5.m

    Energy Science and Technology Software Center (OSTI)

    2014-04-01

    Version 3.10.5 is a multi-year Decision Support tool for Distributed Generation (DG). DER-CAM was initially created as an exclusively economic energy model, able to find the cost minimizing combination and operation profile of a set of DER technologies that meet heat and electric loads of a single building or microgrid for a typical test year. Now, version 3.10.5.m solves for a multiple-year horizon the technology choice question, the appropriate capacity for each selected technology asmore » well as the operational and investment schedule. Optimized investment decisions are based on techno-economic criteria, along with site information such as energy loads, economic forecast, and technology characterization. Version 3.10.5 contains: 1. a PV and battery degradation model and 2. variable performance for technologies. Efficiency, investment costs, etc. can vary over time and model technology breakthroughs and advancements.« less

  15. GridAgents DER Testing: Cooperative Research and Development Final Report, CRADA Number CRD-08-265

    SciTech Connect (OSTI)

    Harrison, K.

    2012-04-01

    The project objectives are to perform research, development, and pilot-scale testing of advanced, next-generation distribution operational strategies using ConEdison's 3G: Distribution System of the Future and associated infrastructure for the real-world Test Bed (demonstration network) combined with the Infotility GridAgents: Secure Agent Framework for Energy as the software platform for advanced operational strategies development. The objective is to accelerate high-payoff technologies that, because of their risk, are unlikely to be developed in a timely manner without a partnership between industry and the Federal government. NREL will be responsible for the evaluation of equipment design and control methods for DER integration and testing of prototype DER technologies and control equipment at the NREL test facility.

  16. Distributed Energy Resources Customer Adoption Model (DER-CAM), Investment & Planing Version 3.10.5.m

    Energy Science and Technology Software Center (OSTI)

    2014-04-01

    Version 3.10.5 is a multi-year Decision Support tool for Distributed Generation (DG). DER-CAM was initially created as an exclusively economic energy model, able to find the cost minimizing combination and operation profile of a set of DER technologies that meet heat and electric loads of a single building or microgrid for a typical test year. Now, version 3.10.5.m solves for a multiple-year horizon the technology choice question, the appropriate capacity for each selected technology asmorewell as the operational and investment schedule. Optimized investment decisions are based on techno-economic criteria, along with site information such as energy loads, economic forecast, and technology characterization. Version 3.10.5 contains: 1. a PV and battery degradation model and 2. variable performance for technologies. Efficiency, investment costs, etc. can vary over time and model technology breakthroughs and advancements.less

  17. Al{sub 70}Pd{sub 21.5}Mn{sub 8.5}: A quasicrystal showing the de haas-van Alphen effect

    SciTech Connect (OSTI)

    Haanappel, E.G.; Kycia, S.W.; Harmon, B.N.; Canfield, P.C.; Goldman, A.I.; Rabson, D.A.; Thompson, J.D.; Mueller, F.M.

    1995-07-01

    We have measured the de Haas-van Alphen effect in the icosahedral quasicrystal Al{sub 70}Pd{sub 21.5}Mn{sub 8.5}. We have found two well-defined frequencies with the magnetic field parallel to a five-fold axis, and two different ones with the field parallel to a two-fold axis. On increasing the temperature, the amplitude of the oscillations substantially decreased, suggesting that the carriers have large masses.

  18. Near-earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations

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

    Dai, Lei; Wang, Chi; Duan, Suping; He, Zhaohai; Wygant, John R.; Cattell, Cynthia A.; Tao, Xin; Su, Zhenpeng; Kletzing, Craig; Baker, Daniel N.; et al

    2015-08-10

    Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeV electron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L~5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ~40 s and a dispersionless injection of electrons up to ~3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front.more » Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons.« less

  19. Near-earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations

    SciTech Connect (OSTI)

    Dai, Lei; Wang, Chi; Duan, Suping; He, Zhaohai; Wygant, John R.; Cattell, Cynthia A.; Tao, Xin; Su, Zhenpeng; Kletzing, Craig; Baker, Daniel N.; Li, Xinlin; Malaspina, David; Blake, J. Bernard; Fennell, Joseph; Claudepierre, Seth; Turner, Drew L.; Reeves, Geoffrey D.; Funsten, Herbert O.; Spence, Harlan E.; Angelopoulos, Vassilis; Fruehauff, Dennis; Chen, Lunjin; Thaller, Scott; Breneman, Aaron; Tang, Xiangwei

    2015-08-10

    Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeV electron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L~5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ~40 s and a dispersionless injection of electrons up to ~3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front. Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons.

  20. Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations

    SciTech Connect (OSTI)

    Fu, Xiangrong; Cowee, Misa M.; Friedel, Reinhard H.; Funsten, Herbert O.; Gary, S. Peter; Hospodarsky, George B.; Kletzing, Craig; Kurth, William; Larsen, Brian A.; Liu, Kaijun; MacDonald, Elizabeth A.; Reeves, Geoffrey D.; Skoug, Ruth M.; Winske, Dan

    2014-10-22

    Magnetospheric banded chorus is enhanced whistler waves with frequencies ωr < Ωe, where Ωe is the electron cyclotron frequency, and a characteristic spectral gap at ωr ≃ Ωe/2. This paper uses spacecraft observations and two-dimensional particle-in-cell simulations in a magnetized, homogeneous, collisionless plasma to test the hypothesis that banded chorus is due to local linear growth of two branches of the whistler anisotropy instability excited by two distinct, anisotropic electron components of significantly different temperatures. The electron densities and temperatures are derived from Helium, Oxygen, Proton, and Electron instrument measurements on the Van Allen Probes A satellite during a banded chorus event on 1 November 2012. The observations are consistent with a three-component electron model consisting of a cold (a few tens of eV) population, a warm (a few hundred eV) anisotropic population, and a hot (a few keV) anisotropic population. The simulations use plasma and field parameters as measured from the satellite during this event except for two numbers: the anisotropies of the warm and the hot electron components are enhanced over the measured values in order to obtain relatively rapid instability growth. The simulations show that the warm component drives the quasi-electrostatic upper band chorus and that the hot component drives the electromagnetic lower band chorus; the gap at ~Ωe/2 is a natural consequence of the growth of two whistler modes with different properties.

  1. Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations

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

    Fu, Xiangrong; Cowee, Misa M.; Friedel, Reinhard H.; Funsten, Herbert O.; Gary, S. Peter; Hospodarsky, George B.; Kletzing, Craig; Kurth, William; Larsen, Brian A.; Liu, Kaijun; et al

    2014-10-22

    Magnetospheric banded chorus is enhanced whistler waves with frequencies ωr < Ωe, where Ωe is the electron cyclotron frequency, and a characteristic spectral gap at ωr ≃ Ωe/2. This paper uses spacecraft observations and two-dimensional particle-in-cell simulations in a magnetized, homogeneous, collisionless plasma to test the hypothesis that banded chorus is due to local linear growth of two branches of the whistler anisotropy instability excited by two distinct, anisotropic electron components of significantly different temperatures. The electron densities and temperatures are derived from Helium, Oxygen, Proton, and Electron instrument measurements on the Van Allen Probes A satellite during a bandedmore » chorus event on 1 November 2012. The observations are consistent with a three-component electron model consisting of a cold (a few tens of eV) population, a warm (a few hundred eV) anisotropic population, and a hot (a few keV) anisotropic population. The simulations use plasma and field parameters as measured from the satellite during this event except for two numbers: the anisotropies of the warm and the hot electron components are enhanced over the measured values in order to obtain relatively rapid instability growth. The simulations show that the warm component drives the quasi-electrostatic upper band chorus and that the hot component drives the electromagnetic lower band chorus; the gap at ~Ωe/2 is a natural consequence of the growth of two whistler modes with different properties.« less

  2. The occurrence and wave properties of H⁺-, He⁺-, and O⁺-band EMIC waves observed by the Van Allen Probes

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

    Saikin, A. A.; Zhang, J. -C.; Allen, R. C.; Smith, C. W.; Kistler, L. M.; Spence, H. E.; Torbert, R. B.; Kletzing, C. A.; Jordanova, Vania K.

    2015-09-26

    We perform a statistical study of electromagnetic ion cyclotron (EMIC) waves detected by the Van Allen Probes mission to investigate the spatial distribution of their occurrence, wave power, ellipticity, and normal angle. The Van Allen Probes have been used which allow us to explore the inner magnetosphere (1.1 to 5.8 RE). Magnetic field measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science on board the Van Allen Probes are used to identify EMIC wave events for the first 22 months of the mission operation (8 September 2012 to 30 June 2014). EMIC waves are examined in H⁺-,more » He⁺-, and O⁺-bands. Over 700 EMIC wave events have been identified over the three different wave bands (265 H⁺-band events, 438 He⁺-band events, and 68 O⁺-band events). EMIC wave events are observed between L = 2 – 8, with over 140 EMIC wave events observed below L = 4. The results show that H⁺-band EMIC waves have two peak magnetic local time (MLT) occurrence regions: pre-noon (09:00 < MLT ≤ 12:00) and afternoon (15:00 < MLT ≤ 17:00) sectors. He⁺-band EMIC waves feature an overall stronger dayside occurrence. O⁺-band EMIC waves have one peak region located in the morning sector at lower L shells (L < 4). He⁺-band EMIC waves average the highest wave power overall (>0.1 nT²/Hz), especially in the afternoon sector. Ellipticity observations reveal that linearly polarized EMIC waves dominate in lower L shells.« less

  3. The occurrence and wave properties of H⁺-, He⁺-, and O⁺-band EMIC waves observed by the Van Allen Probes

    SciTech Connect (OSTI)

    Saikin, A. A.; Zhang, J. -C.; Allen, R. C.; Smith, C. W.; Kistler, L. M.; Spence, H. E.; Torbert, R. B.; Kletzing, C. A.; Jordanova, Vania K.

    2015-09-26

    We perform a statistical study of electromagnetic ion cyclotron (EMIC) waves detected by the Van Allen Probes mission to investigate the spatial distribution of their occurrence, wave power, ellipticity, and normal angle. The Van Allen Probes have been used which allow us to explore the inner magnetosphere (1.1 to 5.8 RE). Magnetic field measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science on board the Van Allen Probes are used to identify EMIC wave events for the first 22 months of the mission operation (8 September 2012 to 30 June 2014). EMIC waves are examined in H⁺-, He⁺-, and O⁺-bands. Over 700 EMIC wave events have been identified over the three different wave bands (265 H⁺-band events, 438 He⁺-band events, and 68 O⁺-band events). EMIC wave events are observed between L = 2 – 8, with over 140 EMIC wave events observed below L = 4. The results show that H⁺-band EMIC waves have two peak magnetic local time (MLT) occurrence regions: pre-noon (09:00 < MLT ≤ 12:00) and afternoon (15:00 < MLT ≤ 17:00) sectors. He⁺-band EMIC waves feature an overall stronger dayside occurrence. O⁺-band EMIC waves have one peak region located in the morning sector at lower L shells (L < 4). He⁺-band EMIC waves average the highest wave power overall (>0.1 nT²/Hz), especially in the afternoon sector. Ellipticity observations reveal that linearly polarized EMIC waves dominate in lower L shells.

  4. Julie Crenshaw Van Fleet

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

    ... Why are you assuming that the use of TRONA causes no changes in any of the emitted pollutants, harm to health, or a nuisance that causes people to cough? During December of 2006 ...

  5. Abe Van Luik

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

    CBFO oversees and owns the Waste Isolation Pilot Plant (WIPP). Abe joined CBFO after several decades of working on the Yucca Mountain Project in Nevada, where he served as Senior ...

  6. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    ... together through weak van der Waals forces to form larger conglomerates that span inmore size from nanometer to micrometer scale. less Full Text Available July 2015 , Springer

  7. Charged pion form factor between $Q^2$=0.60 and 2.45 GeV$^2$...

    Office of Scientific and Technical Information (OSTI)

    ... Paul ; Reinhold, Joerg ; Roche, Julie ; Roos, Philip ; Sarty, Adam ; Shin, Ilkyoung ; Smith, Gregory ; Stepanyan, Stepan ; Tang, Liguang ; Tvaskis, Vladas ; van der Meer, Rob ; ...

  8. Charged pion form factor between $Q^2$=0.60 and 2.45 GeV$^2$...

    Office of Scientific and Technical Information (OSTI)

    Paul ; Reinhold, Joerg ; Roche, Julie ; Roos, Philip ; Sarty, Adam ; Shin, Ilkyoung ; Smith, Gregory ; Stepanyan, Stepan ; Tang, Liguang ; Tvaskis, Vladas ; van der Meer, Rob ; ...

  9. Two-dimensional GaSe/MoSe2 Misfit Bilayer Heterojunctions by...

    Office of Scientific and Technical Information (OSTI)

    fabricated via van der Waals (vdW) or edge epitaxy, constructing heterostructures from monolayers of layered semiconductors with large lattice misfits still remains challenging. ...

  10. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... In general, we expected to probe typical van der Waals interactions, consisting of a ... ; Dipartimento di Chimica, Biologia e Biotecnologie, Universit degli Studi ...

  11. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Roncaratti, Luiz F. Dipartimento di Chimica, Biologia e Biotecnologie, Universit degli ... In general, we expected to probe typical van der Waals interactions, consisting of a ...

  12. Final Progress Report (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    properties of graphene and its derivatives, such as bi-layer graphene, graphene-based van der Waals heterostructures, strained graphene, as well as graphene on various surfaces. ...

  13. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Direct observation of adsorption geometry for the van der Waals adsorption of a single -conjugated hydrocarbon molecule on Au(111) Kim, Ju-Hyung ; Surface and Interface Science ...

  14. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Tracking lithium transport and electrochemical reactions in nanoparticles Wang, Feng ; Yu, Hui-Chia ; Chen, Min-Hua ; Wu, Lijun ; Pereira, Nathalie ; Van der Ven, Anton ; Thornton, ...

  15. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... from nanoscale structure suggests a structural rearrangement in which hexagonal layers ... January 2015 Magnetic structure and phase stability of the van der Waals bonded ...

  16. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Tuning the electronic structure of monolayer graphene Mo S 2 van der Waals ... Optical Third-Harmonic Generation in Graphene Hong, Sung-Young ; Dadap, Jerry I. ; ...

  17. The potential for distributed generation in Japanese prototype buildings: A DER-CAM analysis of policy, tariff design, building energy use, and technology development (English Version)

    SciTech Connect (OSTI)

    Zhou, Nan; Marnay, Chris; Firestone, Ryan; Gao, Weijun; Nishida, Masaru

    2004-10-15

    The August 2003 blackout of the northeastern U.S. and CANADA caused great economic losses and inconvenience to New York City and other affected areas. The blackout was a warning to the rest of the world that the ability of conventional power systems to meet growing electricity demand is questionable. Failure of large power systems can lead to serious emergencies. Introduction of on-site generation, renewable energy such as solar and wind power and the effective utilization of exhaust heat is needed, to meet the growing energy demands of the residential and commercial sectors. Additional benefit can be achieved by integrating these distributed technologies into distributed energy resource (DER) systems. This work demonstrates a method for choosing and designing economically optimal DER systems. An additional purpose of this research is to establish a database of energy tariffs, DER technology cost and performance characteristics, and building energy consumption for Japan. This research builds on prior DER studies at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) and with their associates in the Consortium for Electric Reliability Technology Solutions (CERTS) and operation, including the development of the microgrid concept, and the DER selection optimization program, the Distributed Energy Resources Customer Adoption Model (DER-CAM). DER-CAM is a tool designed to find the optimal combination of installed equipment and an idealized operating schedule to minimize a site's energy bills, given performance and cost data on available DER technologies, utility tariffs, and site electrical and thermal loads over a test period, usually an historic year. Since hourly electric and thermal energy data are rarely available, they are typically developed by building simulation for each of six end use loads used to model the building: electric-only loads, space heating, space cooling, refrigeration, water heating, and natural-gas-only loads. DER-CAM provides a

  18. Plug-in Electric Vehicle Interactions with a Small Office Building: An Economic Analysis using DER-CAM

    SciTech Connect (OSTI)

    Momber, Ilan; Gomez, Tomás; Venkataramanan, Giri; Stadler, Michael; Beer, Sebastian; Lai, Judy; Marnay, Chris; Battaglia, Vincent

    2010-06-01

    It is generally believed that plug-in electric vehicles (PEVs) offer environmental and energy security advantages compared to conventional vehicles. Policies are stimulating electric transportation deployment, and PEV adoption may grow significantly. New technology and business models are being developed to organize the PEV interface and their interaction with the wider grid. This paper analyzes the PEVs' integration into a building's Energy Management System (EMS), differentiating between vehicle to macrogrid (V2M) and vehicle to microgrid (V2m) applications. This relationship is modeled by the Distributed Energy Resources Customer Adoption Model (DER-CAM), which finds optimal equipment combinations to meet microgrid requirements at minimum cost, carbon footprint, or other criteria. Results derive battery value to the building and the possibility of a contractual affiliation sharing the benefit. Under simple annual fixed payments and energy exchange agreements, vehicles are primarily used to avoid peak demand charges supplying cheaper off-peak electricity to the building during workdays.

  19. High-field magnetoresistance and de Haas--van Alphen effect in antiferromagnetic PrB sub 6 and NdB sub 6

    SciTech Connect (OSTI)

    Onuki, Y.; Umezawa, A.; Kwok, W.K.; Crabtree, G.W. ); Nishihara, M.; Yamazaki, T.; Omi, T.; Komatsubara, T. )

    1989-12-01

    The transport properties and the de Haas--van Alphen (dHvA) effect have been measured for antiferromagnetic PrB{sub 6} and NdB{sub 6}. The number of conduction electrons is approximately one per unit cell. The magnetoresistance shows the existence of open orbits, implying a multiply connected Fermi surface. The angular dependence of the magnetoresistance is roughly similar to that of the reference material, LaB{sub 6}. The dHvA data in PrB{sub 6} show both paramagnetic and antiferromagnetic Fermi surfaces. The antiferromagnetic Fermi surface arises from new magnetic Brillouin zone boundaries and antiferromagnetic gaps introduced by the magnetic order, and the paramagnetic Fermi surface from magnetic breakdown through the small antiferromagnetic gaps in high field. Hybridization between the conduction electrons and the {ital f} electrons has been observed through the cyclotron masses, which in PrB{sub 6} are three times larger than the corresponding masses of LaB{sub 6}. In NdB{sub 6} only the antiferromagnetic Fermi surface, quite different from those of LaB{sub 6} and PrB{sub 6}, has been observed.

  20. High field magnetoresistance and de Haas-van Alphen effect in antiferromagnetic PrB/sub 6/ and NdB/sub 6/

    SciTech Connect (OSTI)

    Onuki, Y.; Umezawa, A.; Kwok, W.K.; Crabtree, G.W.; Nishihara, M.; Yamazaki, T.; Omi, T.; Komatsubara, T.

    1987-08-01

    The transport properties and the de Haas-van Alphen (dHvA) effect have been measured for antiferromagnetic PrB/sub 6/ and NdB/sub 6/. The number of conduction electrons is approximately one per unit cell. The magnetoresistance shows the existence of open orbits implying a multiply connected Fermi surface. The angular dependence of the magnetoresistance is roughly similar to that of the reference material, LaB/sub 6/. The dHvA data in PrB/sub 6/ shows both paramagnetic and antiferromagnetic Fermi surfaces. The antiferromagnetic Fermi surface arises from new magnetic Brillouin zone boundaries and antiferromagnetic gaps introduced by the magnetic order, and the paramagnetic Fermi surface from magnetic breakdown through the small antiferromagnetic gaps in high field. Hybridization between the conduction electrons and the f electrons has been observed through the cyclotron masses, which in PrB/sub 6/ are three times larger than the corresponding masses of LaB/sub 6/. In NdB/sub 6/ only the antiferromagnetic Fermi surface, quite different from those of LaB/sub 6/ and PrB/sub 6/, has been observed. 26 refs., 10 figs., 3 tabs.

  1. Correlated Pc4-5 ULF waves, whistler-mode chorus, and pulsating aurora observed by the Van Allen Probes and ground-based systems

    SciTech Connect (OSTI)

    Jaynes, A. N.; Lessard, M. R.; Takahashi, K.; Ali, A. F.; Malaspina, D. M.; Michell, R. G.; Spanswick, E. L.; Baker, D. N.; Blake, J. B.; Cully, C.; Donovan, E. F.; Kletzing, C. A.; Reeves, G. D.; Samara, M.; Spence, H. E.; Wygant, J. R.

    2015-10-28

    Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch angle scattering of tens of keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and tens of keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4–5 compressional pulsations and modulation of whistler-mode chorus using Time History of Events and Macroscale Interactions during Substorms. In the current study, we present simultaneous in situ observations of structured chorus waves and an apparent field line resonance (in the Pc4–5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4–5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth's atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. As a result, such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades and may be a result of nonlinear chorus wave interactions in the equatorial region.

  2. Correlated Pc4-5 ULF waves, whistler-mode chorus, and pulsating aurora observed by the Van Allen Probes and ground-based systems

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

    Jaynes, A. N.; Lessard, M. R.; Takahashi, K.; Ali, A. F.; Malaspina, D. M.; Michell, R. G.; Spanswick, E. L.; Baker, D. N.; Blake, J. B.; Cully, C.; et al

    2015-10-28

    Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch angle scattering of tens of keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and tens of keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4–5 compressional pulsations and modulation of whistler-mode chorus using Time History of Events and Macroscale Interactions during Substorms. In the current study, we present simultaneous in situ observations of structured chorusmore » waves and an apparent field line resonance (in the Pc4–5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4–5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth's atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with the same modulation in a nearby pulsating aurora patch. As a result, such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades and may be a result of nonlinear chorus wave interactions in the equatorial region.« less

  3. A polynomial approach to determining the van Everdingen-Hurst dimensionless variables P(t/sub d/) and Q(t/sub d/) for water encroachment modeling

    SciTech Connect (OSTI)

    Klins, M.A.; Bouchard, A.J.; Cable, C.L.

    1986-01-01

    Classical reservoir engineering reserve estimates and simulation studies for water-driven reservoirs have relied on the traditional van-Everdingen/Hurst approach for Carter/Tracy modification to estimate water encroachment. The predicated volume of water influxed into a reservoir is a function of either of two dimensionless variables, P(t/sub d/) or Q(t/sub d/), depending on which encroachment technique is employed. To estimate values of P(t/sub d/) or Q(t/sub d/), table lookup and interpolation between time entries, and for finite aquifers an additional interpolation between aquifer sizes, may be needed. The vE/H or C/T table lookup and interpolation approach holds several drawbooks. Included are (i) storage requirements for computer applications, (ii) cumbersome, time consuming application, (iii) accuracy questions due to interpolation, (iv) table limitations; finite aquifer/reservoir size ratios of less than ten, and (v) the Carter/Tracy approach requires derivatives of the P(t/sub d/) tabular values. This paper presents four sets of simple polynomials that are easy to implement in order to obtain accurate values of P(t/sub d/) of Q(t/sub d/) for either the finite or infinite radial aquifer case. Derivatives of the P(t/sub d/) polynomials have also been prepared. The average absolute error between polynomially determined values of P(t/sub d/) for finite and infinite aquifiers and the numerically correct solution is less than 0.03% and 0.02%, respectively. Similarly, average absolute errors between finite and infinite Q(t/sub d/) estimates and their numerically correct counterparts are less than 0.10% and 0.05%.

  4. Van Andel Research Institute, Los

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

    Los Alamos National Laboratory to develop detailed computational model to study lung cancer September 14, 2015 LOS ALAMOS, N.M., Sept. 14, 2015-Scientists are developing a new...

  5. Van Andel Research Institute, Los

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

    Vampire Power Is Scary All Year Round Vampire Power Is Scary All Year Round November 8, 2010 - 12:46pm Addthis Chris Stewart Senior Communicator at DOE's National Renewable Energy Laboratory Last week, U.S. Department of Energy Secretary Steven Chu posted information about slaying energy vampires on his Facebook page. (He also posted a picture of himself as a zombie, which is also is very scary!) Energy vampires are appliances that even when turned off utilize a small amount of electricity,

  6. Stefanie Van Wychen | Bioenergy | NREL

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

    Research Scientist - Biomass Analysis, National Renewable Energy Laboratory (NREL), National Bioenergy Center (NBC), 2013-present Research Technician - Biomass Analysis, NREL, NBC, ...

  7. Secretary Comments on the Selection of the Next Executive Director...

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

    Washington, D.C. - The Governing Board of the International Energy Agency (IEA) today announced that their 28 members have selected Maria Van der Hoeven of the Netherlands, the ...

  8. Final Technical Report: DE-FG02-08ER41562

    Office of Scientific and Technical Information (OSTI)

    G. Riess, M. W. Richmond, R. Romani, M. Smith, N. Takanashi, K. Tokita, K. van der ... S. W. Jha, H. Lampeitl, M. Sako, M. Smith, C. Zheng, R. C. Nichol, B. Bassett, R. ...

  9. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    ... Tapia, Juan Carlos ; et al Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic ...

  10. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Crystallographic analyses of CocE-L169KG173Q, determined at1.6-angstrom resolution, suggest that stabilization involves enhanced domain-domain interactions involving van der ...

  11. SREL Reprint #3016

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

    Chiara Mastretta1, Tanja Barac1, Jaco Vangronsveld1, Lee Newman2, Safiyh Taghavi3, and Daniel van der Lelie3 1Environmental Biology, Hasselt University, Agoralaan, Building D,...

  12. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Ware, Doreen (1) Wu, Xiao (1) Yoo, Shinjae (1) Zhang, Yian Biao (1) Zhu, Wei (1) van der ... Safiyh ; Wu, Xiao ; Ouyang, Liming ; Zhang, Yian Biao ; Stadler, Andrea ; McCorkle, ...

  13. Center for Nanophase Materials Sciences (CNMS) - Publications

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

    in Good Solvent," Soft Matter 5 (9), 1897-1904 (2009). Arenholz, E.; van der Laan, G.; Yang, F.; Kemik, N.; Biegalski, M. D.; Christen, H. M.; Takamura, Y, "Magnetic Structure of...

  14. BPA-2016-00257-FOIA Request

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

    Dear Kim Winn, Born Dennis van der Winn Kim S CBPAl - CGI -Bl RE: Bonneville Power Administration software Friday, December 04, 2015 8:09:45 AM My ma iling address is: P.O. Box...

  15. Spectral Induced

    Office of Scientific and Technical Information (OSTI)

    ... SIP response at frequencies between 0.11000 Hz using a NI-4461 dynamic signal analyzer. ... C. H. van Der Weijden, 2005, Surface chemistry of disordered mackinawite (FeS): ...

  16. Oxidation and crystal field effects in uranium (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    5, 2016 Title: Oxidation and crystal field effects in uranium Authors: Tobin, J. G. ; Yu, S.-W. ; Booth, C. H. ; Tyliszczak, T. ; Shuh, D. K. ; van der Laan, G. ; Sokaras, D. ;...

  17. Iran Thomas Auditorium, 8600

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

    Biology Matthias Scheffler Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany CNMS D D I I S S C C O O V V E E R R Y Y SEMINAR SERIES Abstract: Dispersive or van...

  18. Evaluation and combined geophysical interpretations of NURE and related geoscience data in the Van Horn, Pecos, Marfa, Fort Stockton, Presidido, and Emory Peak quadrangles, Texas. Volume 1. Final report

    SciTech Connect (OSTI)

    Keller, G.R.; Hinze, W.J.; Aiken, C.L.V.; Goodell, P.C.; Roy, R.F.; Pingitore, N.E.

    1981-09-01

    This report (two volumes) is the culmination of a two-year study of the six Trans-Pecos Texas quadrangles (Van Horn, Pecos, Marfa, Fort Stockton, Presidio, and Emory Park) surveyed as part of the National Uranium Resource Evaluation (NURE) program. Volume I contains a discussion of the aeromagnetic, gravity and geochemical data, their processing, and their analysis. The geologic history and setting of the Trans-Pecos are discussed along with the uranium potential of the region. Uranium anomalies and occurrences characteristic of numerous different NURE classes are present in the study area, and information is presented on 33 drill holes into these targets. Volume II is a folio of maps reduced to a scale of 1:500,000. Geologic maps for each of the six quadrangles are included and the geophysical maps have been prepared to be overlays for the goelogic maps. In addition to the geologic maps, residual aeromagnetic anomaly, complete Bouguer gravity anomaly, flight line index, gravity station index, and anomaly interpretative maps were prepared for each quadrangle. A large suite of digitally processed maps of gravity and aeromagnetic data were prepared and are included in Volume II.

  19. Rapid enhancement of low energy (<100 eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms

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

    Yue, Chao; Li, Wen; Reeves, Geoffrey D.; Nishimura, Yukitoshi; Zong, Qiugang; Ma, Qianli; Bortnik, Jacob; Thorne, Richard M.; Spence, Harlan E.; Kletzing, Craig A.; et al

    2016-07-15

    Interactions between interplanetary (IP) shocks and the Earth's magnetosphere manifest many important space physics phenomena including low-energy ion flux enhancements and particle acceleration. In order to investigate the mechanisms driving shock-induced enhancement of low-energy ion flux, we have examined two IP shock events that occurred when the Van Allen Probes were located near the equator while ionospheric and ground observations were available around the spacecraft footprints. We have found that, associated with the shock arrival, electromagnetic fields intensified, and low-energy ion fluxes, including H+, He+, and O+, were enhanced dramatically in both the parallel and perpendicular directions. During the 2more » October 2013 shock event, both parallel and perpendicular flux enhancements lasted more than 20 min with larger fluxes observed in the perpendicular direction. In contrast, for the 15 March 2013 shock event, the low-energy perpendicular ion fluxes increased only in the first 5 min during an impulse of electric field, while the parallel flux enhancement lasted more than 30 min. In addition, ionospheric outflows were observed after shock arrivals. From a simple particle motion calculation, we found that the rapid response of low-energy ions is due to drifts of plasmaspheric population by the enhanced electric field. Furthermore, the fast acceleration in the perpendicular direction cannot solely be explained by E × B drift but betatron acceleration also plays a role. Adiabatic acceleration may also explain the fast response of the enhanced parallel ion fluxes, while ion outflows may contribute to the enhanced parallel fluxes that last longer than the perpendicular fluxes.« less

  20. Dodge B2500 dedicated CNG van

    SciTech Connect (OSTI)

    Eudy, L.

    2000-04-19

    The US Department of Energy (DOE) is promoting the use of alternative fuels and alternative fuel vehicles (AFVs). To support this activity, DOE has directed the National Renewable Energy Laboratory (NREL) to conduct projects to evaluate the performance and acceptability of light-duty AFVs. The authors tested a 1999 B2500 dedicated CNG Ram Wagon with a 5.2L V8 engine. The vehicle was run through a series of tests explained briefly in this fact sheet.

  1. NREL: Energy Sciences - Jao van de Lagemaat

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

    worked as a postdoctoral researcher at NREL. His studies focused on charge transport and recombination in dye-sensitized solar cells. His papers in this field have proven seminal...

  2. Women @ Energy: Kerstin Kleese van Dam

    Broader source: Energy.gov [DOE]

    "Working in with different science domains means that there is never a dull moment. My technical abilities and creativity are consistently challenged by their evolving requirements, pushing to create new solutions that take us to the next level." Read more from Kerstin on her profile here.

  3. Transesterification: Laboratory Analytical Procedure (LAP) Van...

    Office of Scientific and Technical Information (OSTI)

    Wychen, S.; Laurens, L. M. L. 09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES BIOMASS; ALGAE; LABORATORY ANALYTICAL PROCEDURES; LAPS; TOTAL LIPIDS; FATTY ACID METHYL ESTERS; FAME;...

  4. VanDoc_135908_1

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

    ... Market for New Coal Power Plant Technology 0 50 100 150 200 250 300 350 400 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 Coal-Fired Plant Capacity (GW) EIA Projected Coal ...

  5. On coagulation mechanisms of charged nanoparticles produced by combustion of hydrocarbon and metallized fuels

    SciTech Connect (OSTI)

    Savel'ev, A. M.; Starik, A. M.

    2009-02-15

    The contributions of van der Waals, Coulomb, and polarization interactions between nanometersized particles to the particle coagulation rate in both free-molecular and continuum regimes are analyzed for particle charges of various magnitudes and signs. Analytical expressions are obtained for the coagulation rate constant between particles whose interaction in the free-molecular regime is described by a singular potential. It is shown that van der Waals and polarization forces significantly increase the coagulation rate between a neutral and a charged particle (by a factor of up to 10) and can even suppress the Coulomb repulsion between like-charged particles of widely different sizes.

  6. Electric dipole polarizabilities at imaginary frequencies for hydrogen, the alkali-metal, alkaline-earth, and noble gas atoms

    SciTech Connect (OSTI)

    Derevianko, Andrei Porsev, Sergey G. Babb, James F.

    2010-05-15

    The electric dipole polarizabilities evaluated at imaginary frequencies for hydrogen, the alkali-metal atoms, the alkaline-earth atoms, and the noble gases are tabulated along with the resulting values of the atomic static polarizabilities, the atom-surface interaction constants, and the dispersion (or van der Waals) constants for the homonuclear and the heteronuclear diatomic combinations of the atoms.

  7. Verband der Deutschen Biokraftstoffindustrie VDB | Open Energy...

    Open Energy Info (EERE)

    interests of 19 members, who have at their disposal almost the entire national biodiesel production capacity in Germany (approx. 1.2m tons in 2004). Coordinates: 52.516074,...

  8. Mysterious electron stash found hidden among Van Allen belts

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

    have confirmed a never-before-seen phenomenon-a long-lived zone of high-energy electrons residing between the inner and outer radiation belts. (Credit: NASA illustration)...

  9. Wave-driven butterfly distribution of Van Allen belt relativistic...

    Office of Scientific and Technical Information (OSTI)

    ... half-width df, a band between f and f (ref. 51). b2 2Bt2 VPdf erf v df ff (f - fm)' (df)2 . (4) here Bt2 is the wave amplitude in units of Tesla and erf is the error function. ...

  10. Major General Hans A. Van Winkle Director of Civil Works

    Office of Legacy Management (LM)

    supported the Nation' s early atomic energy program; @ DVIW w1n SO" I"* on reC"CRa Dam, b. ... Shall maintain records of determination of eligibility and other files, documents and ...

  11. Wave-driven butterfly distribution of Van Allen belt relativistic...

    Office of Scientific and Technical Information (OSTI)

    He, Yihua 1 ; Baker, D. N. 4 ; Spence, H. E. 5 ; Funsten, H. O. 6 ; Blake, J. B. 7 + Show Author Affiliations Changsha Univ. of Science and Technology, Changsha (China). ...

  12. Extending vanLeer's Algorithm to Multiple Dimensions. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: MultiMat 2012 held September 2-6, 2013 in San Francisco, CA.; Related Information: Proposed for presentation at the MultiMat 2012 held September 2-6, ...

  13. Fleet DNA Project Data Summary Report for Delivery Vans

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

    Vehicles Reporting: 94 Generated: Thu Aug 07, 2014 of Days Included: 974 37 1 3 36 22 5 23 6 7 52 54 4 50 51 48 49 53 55 57 60 Deployment ID 0 20 40 60 80 94 Number of Vehicles ...

  14. Fleet DNA Project Data Summary Report for Service Vans

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

    80% 100% of Vehicles Reporting: 4 of Days Included: 29 Generated: Mon Aug 18, 2014 33 35 Deployment ID 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.0 Number of Vehicles Breakdown of ...

  15. Van Buren County, Iowa: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Iowa Cantril, Iowa Douds, Iowa Farmington, Iowa Keosauqua, Iowa Leando, Iowa Milton, Iowa Mount Sterling, Iowa Stockport, Iowa Retrieved from "http:en.openei.orgw...

  16. Van Allen probes pinpoint driver of speeding electrons

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

    how the acceleration took place. Right now, the team believes that electromagnetic radio waves somehow excite the electrons into a higher-energy state, much like a microwave...

  17. Punam Thakur*, Russell Hardy*, Roger Nelson** and Abraham Van Luik**

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

    Pumpkin Power: Turning Food Waste into Energy Pumpkin Power: Turning Food Waste into Energy November 1, 2013 - 1:28pm Addthis Pumpkin Power: Turning Food Waste into Energy Matthew Loveless Matthew Loveless Data Integration Specialist, Office of Public Affairs What are the key facts? 1.4 billion pounds of pumpkins are produced in the U.S. each year, many of which end up in landfills or compost piles after Halloween. Oakland's EBMUD collects food waste and uses microbes to convert it into methane

  18. United Parcel Service Evaluates Hybrid Electric Delivery Vans...

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

    ... a synchronous brushless, permanent magnet motor (26-kW continuous power, 44-kW peak ... Hybrid-specific engine optimization and calibration might produce more consistent ...

  19. Isotopic Analysis At Nw Basin & Range Region (Kennedy & Van Soest...

    Open Energy Info (EERE)

    ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where...

  20. Isotopic Analysis At Cascades Region (Kennedy & Van Soest, 2007...

    Open Energy Info (EERE)

    ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where...

  1. Alternative Fuels Data Center: Natural Gas Delivery Vans Support...

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    ... Regional Heavy-Duty LNG Fueling Station March 21, 2015 Photo of a street sweeper New Hampshire Fleet Revs up With Natural Gas March 7, 2015 Photo of a truck pulling into a CNG ...

  2. Photo-induced strengthening of weak bonding in noble gas dimers

    SciTech Connect (OSTI)

    Miyamoto, Yoshiyuki; Miyazaki, Takehide; Rubio, Angel

    2014-05-19

    We demonstrate through extensive first-principles time-dependent density functional calculations that attractive van der Waals interaction between closed-shell atoms can be enhanced by light with constant spatial intensity. We illustrate this general phenomenon for a He dimer as a prototypical case of complex van der Waals interactions and show that when excited by light with a frequency close to the 1s → 2p He-atomic transition, an attractive force larger than 7 pN is produced. This force gain is manifested as a larger acceleration of He-He contraction under an optical field. The concerted dynamical motions of the He atoms together with polarity switching of the charge-induced dipole cause the contraction of the dimer. These findings are relevant for the photo-induced control of weakly bonded molecular species, either in gas phase or in solution.

  3. Interpretation of long-range interatomic force

    SciTech Connect (OSTI)

    Buldum, A.; Ciraci, S.; Fong, C.Y.; Nelson, J.S.

    1999-02-01

    Recent direct mechanical measurements of atomic force microscopy showed that the force between the silicon tip and the silicon sample is long range in the attractive region and its magnitude at maximum is relatively smaller. These features disagree with previous theoretical predictions based on the {ital ab initio} calculations. We investigated the nature of forces between a silicon tip and the silicon (111)-(2{times}1) surface by performing first-principles pseudopotential and classical molecular dynamics calculations and by calculating the van der Waals interaction. The first two methods give forces that are short range in nature. Fair agreement between the experiment and theory is obtained when the van der Waals interaction is included. The effect of the tip induced deformation is analyzed. {copyright} {ital 1999} {ital The American Physical Society}

  4. A cohesive law for interfaces in graphene/hexagonal boron nitride heterostructure

    SciTech Connect (OSTI)

    Zhang, Chenxi; Lou, Jun; Song, Jizhou

    2014-04-14

    Graphene/hexagonal boron nitride (h-BN) heterostructure has showed great potential to improve the performance of graphene device. We have established the cohesive law for interfaces between graphene and monolayer or multi-layer h-BN based on the van der Waals force. The cohesive energy and cohesive strength are given in terms of area density of atoms on corresponding layers, number of layers, and parameters in the van der Waals force. It is found that the cohesive law in the graphene/multi-layer h-BN is dominated by the three h-BN layers which are closest to the graphene. The approximate solution is also obtained to simplify the expression of cohesive law. These results are very useful to study the deformation of graphene/h-BN heterostructure, which may have significant impacts on the performance and reliability of the graphene devices especially in the areas of emerging applications such as stretchable electronics.

  5. U.S. Energy Information Administration (EIA) - Conference

    U.S. Energy Information Administration (EIA) Indexed Site

    4 EIA Energy Conference Presentations More than 900 thought leaders from industry, government, and academia turned out for EIA's 2014 Energy Conference, July 14 and 15 at the JW Marriott Hotel in Washington, DC. Participants discussed current and future challenges facing domestic and international energy markets and policymakers. Fred Upton, House Energy & Commerce Committee Maria van der Hoeven, International Energy Agency Eric Slifka, Global Partners LP Daniel Yergin, IHS José Manuel

  6. Non-covalent Bonding in Complex Molecular Systems with Quantum Monte Carlo

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

    | Argonne Leadership Computing Facility non-covalent bonding for a range of paradigm molecular materials Projected atomic polarizability tensors of the so-called "buckyball catcher" supramolecular complex. Carbon atoms sit at the centres of the grey spheroids, and hydrogen atoms at the end of the white sticks. This information is used to calculate the van der Waals interaction energy for this complex and understand its stability. For more information see

  7. Gamma irradiation effects in W films

    SciTech Connect (OSTI)

    Claro, Luiz H.; Santos, Ingrid A.; Silva, Cassia F.

    2013-05-06

    Using the van Der Pauw methodology, the surface resistivity of irradiated tungsten films deposited on Silicon substrate was measured. The films were exposed to {gamma} radiation using a isotopic {sup 60}Co source in three irradiation stages attaining 40.35 kGy in total dose. The obtained results for superficial resistivity display a time annealing features and their values are proportional to the total dose.

  8. Casimir Forces On A Silicon Micromechanical Chip (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Journal Article: Casimir Forces On A Silicon Micromechanical Chip Citation Details In-Document Search Title: Casimir Forces On A Silicon Micromechanical Chip Quantum fluctuations give rise to van der Waals and Casimir forces that dominate the interaction between electrically neutral objects at sub-micron separations. Under the trend of miniaturization, such quantum electrodynamical effects are expected to play an important role in micro- and nano-mechanical devices.

  9. Rotational and angular distributions of NO products from NO-Rg(Rg = He, Ne, Ar) complex photodissociation

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

    Heather L. Holmes-Ross; Hall, Gregory E.; Valenti, Rebecca J.; Yu, Hua -Gen; Lawrance, Warren D.

    2016-01-29

    In this study, we present the results of an investigation into the rotational and angular distributions of the NO A~ state fragment following photodissociation of the NO-He, NO-Ne and NO-Ar van der Waals complexed excited via the A~ ← X~ transition. For each complex the dissociation is probed for several values of Ea, the available energy above the dissociation threshold.

  10. Secretary Comments on the Selection of the Next Executive Director of the

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

    International Energy Agency | Department of Energy Comments on the Selection of the Next Executive Director of the International Energy Agency Secretary Comments on the Selection of the Next Executive Director of the International Energy Agency March 11, 2011 - 12:00am Addthis Washington, D.C. - The Governing Board of the International Energy Agency (IEA) today announced that their 28 members have selected Maria Van der Hoeven of the Netherlands, the former Dutch Minister of the Economy, to

  11. Microsoft PowerPoint - 1 Kevin Brown

    Office of Environmental Management (EM)

    Program Update Interagency Steering Committee on Performance and Risk Assessment Community of Practice Annual Technical Exchange Meeting Richland, Washington December 15-16, 2015 Project Team Members Vanderbilt University & CRESP D. Kosson*, K.G. Brown*, A.C. Garrabrants, S. Mahadevan, J. Branch, F. Sanchez Savannah River National Laboratory (SRNL) C. Langton*; G. Flach*; H. Burns*; R. Seitz, S. Marra; F.G. Smith, III Energy Research Centre of The Netherlands (ECN) & CRESP H. van der

  12. Microsoft PowerPoint - 7 Kevin Brown

    Office of Environmental Management (EM)

    (CBP) Toolsets Kevin G. Brown Vanderbilt University and CRESP Cementitious Barriers Partnership Performance & Risk Assessment Community of Practice Technical Exchange Meeting December 11-12, 2014 Las Vegas NM Project Team Members Vanderbilt University & CRESP D. Kosson*, K.G. Brown*, S. Mahadevan, J. Branch, F. Sanchez Savannah River National Laboratory (SRNL) C. Langton*, G. Flach*, H. Burns*, R. Seitz, S. Marra Energy Research Centre of The Netherlands (ECN) & CRESP H. van der

  13. Entropy of Liquid Water from Ab Initio Molecular Dynamics | Argonne

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

    Leadership Computing Facility Entropy of Liquid Water from Ab Initio Molecular Dynamics Authors: Zhang, C., Spanu,L., Galli, G. We have computed the entropy of liquid water using a two-phase thermodynamic model and trajectories generated by ab initio molecular dynamics simulations. We present the results obtained with semilocal, hybrid, and van der Waals density functionals. We show that in all cases, at the experimental equilibrium density and at temperatures in the vicinity of 300 K, the

  14. Chemical Transformation - Joint Center for Energy Storage Research

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

    February 9, 2015, Research Highlights First-Principles Study of Redox End-Members in Li-Sulfur Batteries Van der Waals-augmented density functional theory (vdW-DF), quasi-particle methods (G0W0), and continuum solvation techniques were used to predict several structural, thermodynamic, spectroscopic, electronic, and surface characteristics of solid-phase redox end-members in Li-S batteries. Read More Chemical Transformation January 27, 2015, Research Highlights A Highly Active Nanostructured

  15. Science Highlights- Center for Solar and Thermal Energy Conversion

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

    0 Click on icons for highlight slides. Click on titles or citations for link to papers. Structural Order-Disorder Transitions and Phonon Conductivity of Partially Filled Skutterudites Hyoungchul Kim, Massoud Kaviany, John C. Thomas, Anton van der Ven, Ctirad Uher, and Baoling Huang Physical Review Letters, 105, 265901 (2010) Filled skutterudites are among the most promising of novel thermoelectric materials for power conversion applications. Their effectiveness can be further improved by finding

  16. Results from Vernier scans during the RHIC 2008 PP Run

    SciTech Connect (OSTI)

    Drees,A.; D Ottavio, T.

    2009-05-04

    Using the vernier scan or Van der Meer scan technique, where one beam is swept stepwise across the other while measuring the collision rate as a function of beam displacement, the transverse beam profiles, the luminosity and the effective cross section of the detector in question can be measured. This report briefly recalls the vernier scan method and presents results from the 100 GeV 2008 RHIC polarized proton (pp) run.

  17. NAMD

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

    NAMD NAMD Description NAMD is a molecular dynamics (MD) program designed for parallel computation. Full and efficient treatment of electrostatic and van der Waals interactions are provided via the (O(N Log N) Particle Mesh Ewald algorithm. NAMD interoperates with CHARMM and X-PLOR as it uses the same force field and includes a rich set of MD features (multiple time stepping, constraints, and dissipatitve dynamics). How to Access NAMD NERSC uses modules to manage access to software. To use the

  18. Parallel Molecular Dynamics Program for Molecules

    Energy Science and Technology Software Center (OSTI)

    1995-03-07

    ParBond is a parallel classical molecular dynamics code that models bonded molecular systems, typically of an organic nature. It uses classical force fields for both non-bonded Coulombic and Van der Waals interactions and for 2-, 3-, and 4-body bonded (bond, angle, dihedral, and improper) interactions. It integrates Newton''s equation of motion for the molecular system and evaluates various thermodynamical properties of the system as it progresses.

  19. Slide 1

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

    Identified a new mechanism for exceptionally strong CO 2 binding in metal- organic frameworks Significance and Impact Surprising discovery of 50% absorption enhancement by tailoring organic components will guide materials design for carbon capture and storage Research Details - MOFs can selectively bind CO 2 over other species common in exhaust gas, making them desirable for carbon capture - Here, researchers quantitatively predicted CO 2 binding in a novel MOF using van der Waals- corrected

  20. Slide 1

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

    predict binding enthalpies of 14 small molecules in 10 unique isostructural metal-organic frameworks, M- MOF-74. 140 systems were elucidated quantitatively in the most rigorous and extensive ab initio study to date. Significance and Impact Newly-proposed MOFs and new understanding of MOF-adsorbate binding chemistry could lead to efficient and inexpensive removal of CO2 and other contaminants from gases mixtures (e.g. flue gas). Research Details - Our calculations employ a nonlocal van der Waals

  1. Supercomputers Help Identify Efficiency-Limiting Defects in LEDs

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

    Supercomputers Help Identify Efficiency-Limiting Defects in LEDs Supercomputers Help Identify Efficiency-Limiting Defects in LEDs July 18, 2016 Contact: Kathy Kincade, kkincade@lbl.gov, +1 510 495 2124 ChrisVanDerWalle PressReleaseImage A conceptual illustration of how defects in a crystal lattice might contribute to nonradiative recombination of electrons and holes in LEDs. Image: Peter Allen Light-emitting diodes (LEDs) have found firm footing in the lighting industry, not just for blue and

  2. Synthesis and Heterostructures of Monolayer Semiconductors | MIT-Harvard

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

    Center for Excitonics Synthesis and Heterostructures of Monolayer Semiconductors August 6, 2015 at 2pm/36-428 Yi-Hsien Lee Department of Materials Science and Engineering, National Tsing Hua University, Taiwan Yi-Hsien Lee Abstract: Monolayers of van der Waals (vdw) materials, such as graphene and MoS2, have been highlighted regarding both scientific and industrial aspects for novel physical phenomenon inherited from the reduced dimensionality. Layered transition metal dichalcogenides (TMD)

  3. NOVEL CONCEPTS FOR ISOTOPIC SEPARATION OF 3HE/4HE

    SciTech Connect (OSTI)

    Roy, L.; Nigg, H.; Watson, H.

    2012-09-04

    The research outlined below established theoretical proof-of-concept using ab initio calculations that {sup 3}He can be separated from {sup 4}He by taking advantage of weak van der Waals interactions with other higher molecular weight rare gases such as xenon. To the best of our knowledge, this is the only suggested method that exploits the physical differences of the isotopes using a chemical interaction.

  4. Wind speed power spectrum analysis for Bushland, Texas

    SciTech Connect (OSTI)

    Eggleston, E.D.

    1996-12-31

    Numerous papers and publications on wind turbulence have referenced the wind speed spectrum presented by Isaac Van der Hoven in his article entitled Power Spectrum of Horizontal Wind Speed Spectrum in the Frequency Range from 0.0007 to 900 Cycles per Hour. Van der Hoven used data measured at different heights between 91 and 125 meters above the ground, and represented the high frequency end of the spectrum with data from the peak hour of hurricane Connie. These facts suggest we should question the use of his power spectrum in the wind industry. During the USDA - Agricultural Research Service`s investigation of wind/diesel system power storage, using the appropriate wind speed power spectrum became a significant issue. We developed a power spectrum from 13 years of hourly average data, 1 year of 5 minute average data, and 2 particularly gusty day`s 1 second average data all collected at a height of 10 meters. While the general shape is similar to the Van der Hoven spectrum, few of his peaks were found in the Bushland spectrum. While higher average wind speeds tend to suggest higher amplitudes in the high frequency end of the spectrum, this is not always true. Also, the high frequency end of the spectrum is not accurately described by simple wind statistics such as standard deviation and turbulence intensity. 2 refs., 5 figs., 1 tab.

  5. Effects of Atomic Scale Roughness at Metal/insulator Interfaces on Metal Work Function

    SciTech Connect (OSTI)

    Ling, Sanliang; Watkins, M. B.; Shlyuger, Alexander L.

    2013-09-26

    We evaluate the performance of different van der Waals (vdW) corrected density functional theory (DFT) methods in predicting the structure of perfect interfaces between the LiF(001), MgO(001), NiO(001) films on the Ag(001) surface and the resulting work function shift of Ag(001). The results demonstrate that including the van der Waals interaction is important for obtaining accurate interface structures and the metal work function shift. The work function shift results from a subtle interplay of several effects strongly affected by even small changes in the interface geometry. This makes the accuracy of theoretical methods insufficient for predicting the shift values better than within 0.2 eV. Most of the existing van der Waals corrected functionals are not particularly suited for studying metal/insulator interfaces. The lack of accurate experimental data on the interface geometries and surface rumpling of insulators hampers the calibration of existing and novel density functionals.

  6. Shock dynamics of phase diagrams

    SciTech Connect (OSTI)

    Moro, Antonio

    2014-04-15

    A thermodynamic phase transition denotes a drastic change of state of a physical system due to a continuous change of thermodynamic variables, as for instance pressure and temperature. The classical van der Waals equation of state is the simplest model that predicts the occurrence of a critical point associated with the gasliquid phase transition. Nevertheless, below the critical temperature theoretical predictions of the van der Waals theory significantly depart from the observed physical behaviour. We develop a novel approach to classical thermodynamics based on the solution of Maxwell relations for a generalised family of nonlocal entropy functions. This theory provides an exact mathematical description of discontinuities of the order parameter within the phase transition region, it explains the universal form of the equations of state and the occurrence of triple points in terms of the dynamics of nonlinear shock wave fronts. -- Highlights: A new generalisation of van der Waals equation of state. Description of phase transitions in terms of shock dynamics of state curves. Proof of the universality of equations of state for a general class of models. Interpretation of triple points as confluence of classical shock waves. Correspondence table between thermodynamics and nonlinear conservation laws.

  7. Role for Distributed Energy Resources (DER) in the Digital Economy

    SciTech Connect (OSTI)

    Key, Thomas S

    2007-11-01

    A large, and growing, part of the Nation's economy either serves or depends upon the information technology industry. These high-tech or "digital" enterprises are characterized by a dependence on electronic devices, need for completely reliable power supply, and intolerance to any power quality problems. In some cases these enterprises are densely populated with electronic loads and have very high energy usage per square foot. Serving these enterprises presents both electric power and equipment cooling challenges. Traditional electric utilities are often hard-pressed to deliver power that meets the stringent requirements of digital customers, and the economic and social consequences of a service quality or reliability problem can be large. New energy delivery and control options must be developed to effectively serve a digital economy. This report explores how distributed energy resources, partnerships between utility and customer to share the responsibility for service quality, innovative facility designs, higher energy efficiencies and waste-heat utilization can be coupled to meet the needs of a growing digital economy.

  8. A Framework for Developing Collaborative DER Programs: Working...

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

    ... For example, for PM10 abatement, this equipment could involve an entire pollution control system of a scrubber (wetdry), baghouse, fabric collector, or microclone technology. For ...

  9. Sorptivity of rocks and soils of the van Genuchten-Mualem type

    SciTech Connect (OSTI)

    Zimmerman, R.W.; Bodvarsson, G.S.

    1991-06-01

    One hydrological process that will have great relevance to the performance of the proposed underground radioactive waste repository at Yucca Mountain, Nevada, is that of the absorption of water from a water-filled fracture into the adjacent unsaturated rock formation. The rate at which water is imbibed by a rock depends on the hydrological properties of the rock and on the initial saturation (or initial capillary suction) of the formation. The hydrological properties that affect imbibition are the relative permeability function and the capillary pressure function. These functions are often collectively referred to as the `characteristic functions` of the porous medium. For one-dimensional absorption, it can be shown that, regardless of the details of the characteristic functions, the total amount of water imbibed by the formation, per unit surface area, will be proportional to the square root of the elapsed time. Hence the ability of a rock or soil to imbibe water can be quantified by a parameter known as the sorptivity S, which is defined such that the cumulative volumetric liquid influx per unit area is given by Q = S{radical}t. The paper discusses the simplification of these characteristic functions of porous medium.

  10. Major General Hans A. Van Winkle Director of Civil Works U.S...

    Office of Legacy Management (LM)

    The contaminants of concern from MED and AEC activities might include industrial chemicals (metal working fluxes, solvents, fuel oil, acids, bases. etc.) and radioactive substances ...

  11. Major General Hans A. Van Winkle Director of Civil Works U.S...

    Office of Legacy Management (LM)

    The contaminants of concern from AEC activities might include industrial chemicals (explosives. explosive residues. metals. beryllium. Solvents, fuel oil. acids. bases. etc.) and ...

  12. Comments by Julie Crenshaw Van Fleet on DOE/SEA-04, Special Environmen...

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

    PM10, PM2.5, and SO2 in 20052006. This AERO report finds exceedances of the NAAQS standards for all these pollutants adjacent to the generating station in residential ...

  13. Jeffrey Van Humbeck | Center for Gas SeparationsRelevant to Clean...

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

    Email: jvh at mit.edu B.Sc in Chemistry (Honours), University of Calgary MA and PhD in Chemistry, Princeton University EFRC research: Covalent organic frameworks (COFs) possess...

  14. Fact #704: December 5, 2011 Fuel Consumption Standards for New Heavy Pickups and Vans

    Office of Energy Efficiency and Renewable Energy (EERE)

    In September 2011 the National Highway Traffic Safety Administration issued the final rule to set standards regulating the fuel use of new vehicles heavier than 8,500 lbs. gross vehicle weight....

  15. 10 Questions for a Computational Scientist: Kerstin Kleese-Van Dam

    Broader source: Energy.gov [DOE]

    Find out how she's using information and data to accelerate systems biology research and how she actively works her network -- through means such as LinkedIn, Facebook, joint conference participation and regular email contact -- to stay atop trends in the field.

  16. VanNessBauck (9-23-11) Fully Executed M439.pdf

    National Nuclear Security Administration (NNSA)

    M439 Attachment 1 Page 1 of 5 Part III - Section J Appendix G List of Applicable Directives and NNSA Policy Letters In addition to the list of applicable directives referenced below, the contractor shall also comply with supplementary directives (e.g., manuals), which are invoked by a Contractor Requirements Document (CRD) attached to a directive referenced below. This List excludes directives that have been granted an exemption from the CRD in whole or in part. For those Directives whereby the

  17. Network Markup Language Base Schema version 1

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

    GFD-R-P.206 NML-WG nml-wg@ogf.org Jeroen van der Ham, UvA (editor) Freek Dijkstra, SURFsara Roman Łapacz, PSNC Jason Zurawski, Internet2 May 2013 Network Markup Language Base Schema version 1 Status of This Document Grid Final Draft (GFD), Proposed Recommendation (R-P). Copyright Notice Copyright c Open Grid Forum (2008-2013). Some Rights Reserved. Distribution is unlim- ited. Abstract This document describes a set of normative schemas which allow the description of computer network topologies.

  18. Thermodynamics: Frontiers and Foundations.

    Energy Science and Technology Software Center (OSTI)

    2009-07-27

    Version 00 Dr. J.D. Lewins has now released the following new book for free distribution: Thermodynamics: Frontiers and Foundations, Preface by Sir Alan Cottrell Introduction 1. Four-Square Foundations: The Laws of Thermodynamics 2. Maximum Entropy and Minimum Energy: The Master Functions and Equations 3. Ideal Gases and their Applications 4. Real Fluids and Some Applications 5. Van der Waals: A Model for Real Fluids 6. Surface Tension: Bubbles and Drops 7. Inert and Reactive Mixtures;more » An introduction to Chemical Thermodynamics 8. Radiation Thermodynamics: Solar Power Potential 9. Outposts of the Empire 10. A Glimpse into Statistical Thermodynamics Envoi« less

  19. On calculating the equilibrium structure of molecular crystals.

    SciTech Connect (OSTI)

    Mattsson, Ann Elisabet; Wixom, Ryan R.; Mattsson, Thomas Kjell Rene

    2010-03-01

    The difficulty of calculating the ambient properties of molecular crystals, such as the explosive PETN, has long hampered much needed computational investigations of these materials. One reason for the shortcomings is that the exchange-correlation functionals available for Density Functional Theory (DFT) based calculations do not correctly describe the weak intermolecular van der Waals' forces present in molecular crystals. However, this weak interaction also poses other challenges for the computational schemes used. We will discuss these issues in the context of calculations of lattice constants and structure of PETN with a number of different functionals, and also discuss if these limitations can be circumvented for studies at non-ambient conditions.

  20. Role of spent shale in oil shale processing and the management of environmental residues. Final technical report, January 1979-May 1980

    SciTech Connect (OSTI)

    Hines, A.L.

    1980-08-15

    The adsorption of hydrogen sulfide on retorted oil shale was studied at 10, 25, and 60/sup 0/C using a packed bed method. Equilibrium isotherms were calculated from the adsorption data and were modeled by the Langmuir, Freundlich, and Polanyi equations. The isosteric heat of adsorption was calculated at three adsorbent loadings and was found to increase with increased loading. A calculated heat of adsorption less than the heat of condensation indicated that the adsorption was primarily due to Van der Waals' forces. Adsorption capacities were also found as a function of oil shale retorting temperature with the maximum uptake occurring on shale that was retorted at 750/sup 0/C.

  1. The nature of the interlayer interaction in bulk and few-layer phosphorus

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

    Shulenburger, Luke; Baczewski, A. D.; Zhu, Z.; Guan, J.; Tomanek, David

    2015-11-02

    Sensitive dependence of the electronic structure on the number of layers in few-layer phosphorene raises a question about the true nature of the interlayer interaction in so-called van der Waals (vdW) solids . We performed quantum Monte Carlo calculations and found that the interlayer interaction in bulk black phosphorus and related few-layer phosphorene is associated with a significant charge redistribution that is incompatible with purely dispersive forces and not captured by density functional theory calculations with different vdW corrected functionals. Lastly, these findings confirm the necessity of more sophisticated treatment of nonlocal electron correlation in total energy calculations.

  2. Hexakis(4-phormylphenoxy)cyclotriphosphazene: X-ray and DFT-calculated structures

    SciTech Connect (OSTI)

    Albayrak, Cigdem Kosar, Basak; Odabasoglu, Mustafa; Bueyuekguengoer, Orhan

    2010-12-15

    The crystal structure of hexakis(4-phormylphenoxy)cyclotriphosphazene is determined by using X-ray diffraction and then the molecular structure is investigated with density functional theory (DFT). X-Ray study shows that the title compound has C-H-{pi} interaction with phosphazene ring. The molecules in the unit cell are packed with Van der Waals and dipole-dipole interactions and the molecules are packed in zigzag shaped. Optimized molecular geometry is calculated with DFT at B3LYP/6-311G(d,p) level. The results from both experimental and theoretical calculations are compared in this study.

  3. Physisorbed H{sub 2}@Cu(100) surface: Potential and spectroscopy

    SciTech Connect (OSTI)

    Bernard, Eddy; Houriez, Céline; Mitrushchenkov, Alexander O.; Guitou, Marie; Chambaud, Gilberte

    2015-02-07

    Using an embedding approach, a 2-D potential energy function has been calculated to describe the physisorption interaction of H{sub 2} with a Cu(100) surface. For this purpose, a cluster model of the system calculated with highly correlated wavefunctions is combined with a periodic Density-Functional-Theory method using van der Waals-DF2 functional. Rotational and vibrational energy levels of physisorbed H{sub 2}, as well as D{sub 2} and HD, are calculated using the 2D embedding corrected potential energy function. The calculated transitions are in a very good agreement with Electron-Energy-Loss-Spectroscopy observations.

  4. Ionic radius of (CF{sub 3}SO{sub 2}){sub 3}C{sup {minus}} and applicability of Stokes law to its propylene carbonate solution

    SciTech Connect (OSTI)

    Ue, Makoto

    1996-11-01

    The ionic radius of (Cf{sub 3}SO{sub 2}){sub 3}C{+-}{sup {minus}} was calculated to be 0.375 nm from its van der Waals volume, which was obtained by molecular mechanics calculations with the aid of its crystallographic data. This radius was correlated with its single ion limiting molar conductivity in propylene carbonate at 25 C, and it was proven that this anion also nearly followed the behavior of perfect slip in Stokes law, as is observed for other popular anions for lithium battery applications.

  5. Energy Gaps and Interaction Blockade in Confined Quantum Systems

    SciTech Connect (OSTI)

    Capelle, K.; Borgh, M.; Kaerkkaeinen, K.; Reimann, S. M.

    2007-07-06

    We investigate universal properties of strongly confined particles that turn out to be dramatically different from what is observed for electrons in atoms and molecules. For a large class of harmonically confined systems, such as small quantum dots and optically trapped atoms, many-body particle addition and removal energies, and energy gaps, are accurately obtained from single-particle eigenvalues. Transport blockade phenomena are related to the derivative discontinuity of the exchange-correlation functional. This implies that they occur very generally, with Coulomb blockade being a particular realization of a more general phenomenon. In particular, we predict a van der Waals blockade in cold atom gases in traps.

  6. Quarkonium-nucleus bound states from lattice QCD

    SciTech Connect (OSTI)

    Beane, S.  R.; Chang, E.; Cohen, S.  D.; Detmold, W.; Lin, H. -W.; Orginos, K.; Parreño, A.; Savage, M.  J.

    2015-06-11

    Quarkonium-nucleus systems are composed of two interacting hadronic states without common valence quarks, which interact primarily through multi-gluon exchanges, realizing a color van der Waals force. We present lattice QCD calculations of the interactions of strange and charm quarkonia with light nuclei. Both the strangeonium-nucleus and charmonium-nucleus systems are found to be relatively deeply bound when the masses of the three light quarks are set equal to that of the physical strange quark. Extrapolation of these results to the physical light-quark masses suggests that the binding energy of charmonium to nuclear matter is B < 40 MeV.

  7. Structural Behaviour of Uranium Sulfide under High Pressure

    SciTech Connect (OSTI)

    Shareef, F.; Singh, S.; Gour, A.; Bhardwaj, P.; Sarwan, M.; Dubey, R. [High Pressure Research Lab, Department of Physics, Barkatullah University, Bhopal-462026 (India); Singh, R. K. [ITM University, Gurgaon, Haryana-122017 (India)

    2011-07-15

    The study of pressure induced structural phase transition of uranium sulphide, which crystallizes in rock salt (B1) structure, has been performed using the well described three body interaction model (TBIPM). Our present TBIP model consists of long range coulombic interaction, three body interactions, Hafemeister and Flygare type short-range overlap repulsion extended upto the second neighbor ions and the van der Waals interaction. The present results are in good agreement with the available experimental data on the phase transition pressure (Pt = 80.2 GPa). So it can be considered as an adequate and suitable model to perform high pressure studies.

  8. Asymmetric spectral broadening of modulated electrostatic ion-cyclotron waves

    SciTech Connect (OSTI)

    Koepke, M.E.; Alport, M.J.; Sheridan, T.E.; Amatucci, W.E.; Carroll, J.J. III

    1994-06-01

    Modulated, current-driven, electrostatic ion-cyclotron (CDEIC) waves are shown to exhibit amplitude and frequency modulation, spectral broadening, and time-averaged frequency pulling. The observed spectral broadening is asymmetric and sensitively dependent on the driving frequency. Qualitative features of the experimental data are reproduced by the forced van der Pol equation and are explainable using processes associated with driven self oscillations. These results may be relevant to ionospheric modification experiments involving the controlled modulation of the natural electrojet. 31 refs., 4 figs.

  9. Experimental study of the valence band of Bi2Se3

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

    Gao, Yi-Bin; He, Bin; Parker, David; Androulakis, Ioannis; Heremans, Joseph P.

    2014-09-26

    The valence band of Bi2Se3 is investigated with Shubnikov - de Haas measurements, galvanomagnetic and thermoelectric transport. At low hole concentration, the hole Fermi surface is closed and box-like, but at higher concentrations it develops tube-like extensions that are open. The experimentally determined density-of-states effective mass is lighter than density-functional theory calculations predict; while we cannot give a definitive explanation for this, we suspect that the theory may lack sufficient precision to compute room-temperature transport properties, such as the Seebeck coefficient, in solids in which there are Van der Waals interlayer bonds.

  10. Experimental study of the valence band of Bi2Se3

    SciTech Connect (OSTI)

    Gao, Yi-Bin; He, Bin; Parker, David; Androulakis, Ioannis; Heremans, Joseph P.

    2014-09-26

    The valence band of Bi2Se3 is investigated with Shubnikov - de Haas measurements, galvanomagnetic and thermoelectric transport. At low hole concentration, the hole Fermi surface is closed and box-like, but at higher concentrations it develops tube-like extensions that are open. The experimentally determined density-of-states effective mass is lighter than density-functional theory calculations predict; while we cannot give a definitive explanation for this, we suspect that the theory may lack sufficient precision to compute room-temperature transport properties, such as the Seebeck coefficient, in solids in which there are Van der Waals interlayer bonds.

  11. Hanford Blog Archive - Hanford Site

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

    May 2010 May 27, 2010 Recovery Act Progress at Hanford Read the full report on ARRA progress (through 3/31) at the Hanford Site. May 25, 2010 Cleaning Up After The Cold War: Hanford's Tank Waste In a recent article for the Daily Kos, former Hanford radiochemist Page van der Linden explains the complexity and importance of tank waste retrieval and processing. May 24, 2010 Department of Energy Strengthens Management of the Waste Treatment Plant in Washington State U.S. Energy Secretary Steven Chu

  12. Stereospecific olefin polymerization catalysts

    DOE Patents [OSTI]

    Bercaw, J.E.; Herzog, T.A.

    1998-01-13

    A metallocene catalyst system is described for the polymerization of {alpha}-olefins to yield stereospecific polymers including syndiotactic, and isotactic polymers. The catalyst system includes a metal and a ligand of the formula shown wherein: R{sup 1}, R{sup 2}, and R{sup 3} are independently selected from the group consisting of hydrogen, C{sub 1} to C{sub 10} alkyl, 5 to 7 membered cycloalkyl, which in turn may have from 1 to 3 C{sub 1} to C{sub 10} alkyls as a substituent, C{sub 6} to C{sub 15} aryl or arylalkyl in which two adjacent radicals may together stand for cyclic groups having 4 to 15 carbon atoms which in turn may be substituted, or Si(R{sup 8}){sub 3} where R{sup 8} is selected from the group consisting of C{sub 1} to C{sub 10} alkyl, C{sub 6} to C{sub 15} aryl or C{sub 3} to C{sub 10} cycloalkyl; R{sup 4} and R{sup 6} are substituents both having van der Waals radii larger than the van der Waals radii of groups R{sup 1} and R{sup 3}; R{sup 5} is a substituent having a van der Waals radius less than about the van der Waals radius of a methyl group; E{sup 1}, E{sup 2} are independently selected from the group consisting of Si(R{sup 9}){sub 2}, Si(R{sup 9}){sub 2}--Si(R{sup 9}){sub 2}, Ge(R{sup 9}){sub 2}, Sn(R{sup 9}){sub 2}, C(R{sup 9}){sub 2}, C(R{sup 9}){sub 2}--C(R{sup 9}){sub 2}, where R{sup 9} is C{sub 1} to C{sub 10} alkyl, C{sub 6} to C{sub 15} aryl or C{sub 3} to C{sub 10} cycloalkyl; and the ligand may have C{sub S} or C{sub 1}-symmetry. Preferred metals are selected from the group consisting of group III, group IV, group V or lanthanide group elements. The catalysts are used to prepare stereoregular polymers including polypropylene from {alpha}-olefin monomers.

  13. Highly Anisotropic Thermal Expansion in Molecular Films of Dicarboxylic Fatty Acids

    SciTech Connect (OSTI)

    Tamam L.; Ocko B.; Kraack, H.; Sloutskin, E.; Deutsch, M.

    2012-05-25

    Angstrom-resolution x-ray measurements reveal the existence of two-dimensional (2D) crystalline order in molecularly thin films of surface-parallel-oriented fatty diacid molecules supported on a liquid mercury surface. The thermal expansion coefficients along the two unit cell vectors are found to differ 17-fold. The high anisotropy of the 2D thermal expansion and the crystalline coherence length are traced to the different bonding in the two directions: van der Waals normal to, and covalent plus hydrogen bonding along the molecular backbone axis. Similarities with, and differences from, negative thermal expansion materials are discussed.

  14. Stereospecific olefin polymerization catalysts

    DOE Patents [OSTI]

    Bercaw, John E.; Herzog, Timothy A.

    1998-01-01

    A metallocene catalyst system for the polymerization of .alpha.-olefins to yield stereospecific polymers including syndiotactic, and isotactic polymers. The catalyst system includes a metal and a ligand of the formula ##STR1## wherein: R.sup.1, R.sup.2, and R.sup.3 are independently selected from the group consisting of hydrogen, C.sub.1 to C.sub.10 alkyl, 5 to 7 membered cycloalkyl, which in turn may have from 1 to 3 C.sub.1 to C.sub.10 alkyls as a substituent, C.sub.6 to C.sub.15 aryl or arylalkyl in which two adjacent radicals may together stand for cyclic groups having 4 to 15 carbon atoms which in turn may be substituted, or Si(R.sup.8).sub.3 where R.sup.8 is selected from the group consisting of C.sub.1 to C.sub.10 alkyl, C.sub.6 to C.sub.15 aryl or C.sub.3 to C.sub.10 cycloalkyl; R.sup.4 and R.sup.6 are substituents both having van der Waals radii larger than the van der Waals radii of groups R.sup.1 and R.sup.3 ; R.sup.5 is a substituent having a van der Waals radius less than about the van der Waals radius of a methyl group; E.sup.1, E.sup.2 are independently selected from the group consisting of Si(R.sup.9).sub.2, Si(R.sup.9).sub.2 --Si(R.sup.9).sub.2, Ge(R.sup.9).sub.2, Sn(R.sup.9).sub.2, C(R.sup.9).sub.2, C(R.sup.9).sub.2 --C(R.sup.9).sub.2, where R.sup.9 is C.sub.1 to C.sub.10 alkyl, C.sub.6 to C.sub.15 aryl or C.sub.3 to C.sub.10 cycloalkyl; and the ligand may have C.sub.S or C.sub.1 -symmetry. Preferred metals are selected from the group consisting of group III, group IV, group V or lanthanide group elements. The catalysts are used to prepare stereoregular polymers including polypropylene from .alpha.-olefin monomers.

  15. Theory of melting at high pressures: Amending density functional theory with quantum Monte Carlo

    SciTech Connect (OSTI)

    Shulenburger, L.; Desjarlais, M. P.; Mattsson, T. R.

    2014-10-01

    We present an improved first-principles description of melting under pressure based on thermodynamic integration comparing Density Functional Theory (DFT) and quantum Monte Carlo (QMC) treatments of the system. The method is applied to address the longstanding discrepancy between density functional theory (DFT) calculations and diamond anvil cell (DAC) experiments on the melting curve of xenon, a noble gas solid where van der Waals binding is challenging for traditional DFT methods. The calculations show excellent agreement with data below 20 GPa and that the high-pressure melt curve is well described by a Lindemann behavior up to at least 80 GPa, a finding in stark contrast to DAC data.

  16. Instrument fieldsclose.sdr

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

    Radar Van GP Van BBSS Cart RWP Met Twr ECOR Radiometry Stands PWR Module 25m

  17. Browse by Discipline -- E-print Network Subject Pathways: Fission...

    Office of Scientific and Technical Information (OSTI)

    V W X Y Z van Benthem, Johan (Johan van Benthem) - Institute for Logic Language and Computation, Universiteit van Amsterdam Van Cleave, Nancy K. (Nancy K. Van Cleave) - Department ...

  18. CuInP2S6 Room Temperature Layered Ferroelectric

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

    Belianinov, Alex; He, Qian; Dziaugys, Andrius; Maksymovych, Petro; Eliseev, Eugene; Borisevich, Albina Y.; Morozovska, Anna N.; Banys, Juras; Vysochanskii, Yulian; Kalinin, Sergei V.

    2015-05-01

    In this paper, we explore ferroelectric properties of cleaved 2-D flakes of copper indium thiophosphate, CuInP2S6 (CITP), and probe size effects along with limits of ferroelectric phase stability, by ambient and ultra high vacuum scanning probe microscopy. CITP belongs to the only material family known to display ferroelectric polarization in a van der Waals, layered crystal at room temperature and above. Our measurements directly reveal stable, ferroelectric polarization as evidenced by domain structures, switchable polarization, and hysteresis loops. We found that at room temperature the domain structure of flakes thicker than 100 nm is similar to the cleaved bulk surfaces,more » whereas below 50 nm polarization disappears. We ascribe this behavior to a well-known instability of polarization due to depolarization field. Furthermore, polarization switching at high bias is also associated with ionic mobility, as evidenced both by macroscopic measurements and by formation of surface damage under the tip at a bias of 4 V—likely due to copper reduction. Mobile Cu ions may therefore also contribute to internal screening mechanisms. Finally, the existence of stable polarization in a van-der-Waals crystal naturally points toward new strategies for ultimate scaling of polar materials, quasi-2D, and single-layer materials with advanced and nonlinear dielectric properties that are presently not found in any members of the growing “graphene family”.« less

  19. CuInP2S6 Room Temperature Layered Ferroelectric

    SciTech Connect (OSTI)

    Belianinov, Alex; He, Qian; Dziaugys, Andrius; Maksymovych, Petro; Eliseev, Eugene; Borisevich, Albina Y.; Morozovska, Anna N.; Banys, Juras; Vysochanskii, Yulian; Kalinin, Sergei V.

    2015-05-01

    In this paper, we explore ferroelectric properties of cleaved 2-D flakes of copper indium thiophosphate, CuInP2S6 (CITP), and probe size effects along with limits of ferroelectric phase stability, by ambient and ultra high vacuum scanning probe microscopy. CITP belongs to the only material family known to display ferroelectric polarization in a van der Waals, layered crystal at room temperature and above. Our measurements directly reveal stable, ferroelectric polarization as evidenced by domain structures, switchable polarization, and hysteresis loops. We found that at room temperature the domain structure of flakes thicker than 100 nm is similar to the cleaved bulk surfaces, whereas below 50 nm polarization disappears. We ascribe this behavior to a well-known instability of polarization due to depolarization field. Furthermore, polarization switching at high bias is also associated with ionic mobility, as evidenced both by macroscopic measurements and by formation of surface damage under the tip at a bias of 4 V—likely due to copper reduction. Mobile Cu ions may therefore also contribute to internal screening mechanisms. Finally, the existence of stable polarization in a van-der-Waals crystal naturally points toward new strategies for ultimate scaling of polar materials, quasi-2D, and single-layer materials with advanced and nonlinear dielectric properties that are presently not found in any members of the growing “graphene family”.

  20. Numerical studies of a plasma diode with external forcing

    SciTech Connect (OSTI)

    Rekaa, V. L.; Pecseli, H. L.; Trulsen, J. K.

    2012-08-15

    With reference to laboratory Q-machine studies we analyze the dynamics of a plasma diode under external forcing. Assuming a strong axial magnetic field, the problem is analyzed in one spatial dimension by a particle-in-cell code. The cathode is assumed to be operated in electron rich conditions, supplying an abundance of electrons. We compare different forcing schemes with the results obtained by solving the van der Pol equation. In one method of forcing we apply an oscillation in addition to the DC end plate bias and consider both amplitude and frequency variations. An alternative method of perturbation consists of modelling an absorbing grid at some internal position. Also in this case we can have a constant frequency with varying amplitude or alternatively an oscillation with chirped frequency but constant amplitude. We find that the overall features of the forced van der Pol equation are recovered, but the details in the plasma response need more attention to the harmonic responses, requiring extensions of the model equation. The analysis is extended by introducing collisional effects, where we emphasize charge exchange collisions of ions, since these processes usually have the largest cross sections and give significant modifications of the diode performance. In particular we find a reduction in oscillator frequency, although a linear scaling of the oscillation time with the system length remains also in this case.

  1. Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

    SciTech Connect (OSTI)

    Al-Hamdani, Yasmine S.; Alf, Dario; von Lilienfeld, O. Anatole; Michaelides, Angelos

    2014-10-22

    Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we show that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B?N?H?) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.

  2. Applying the cold plasma dispersion relation to whistler mode chorus waves: EMFISIS wave measurements from the Van Allen Probes

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

    Hartley, D. P.; Chen, Y.; Kletzing, C. A.; Denton, M. H.; Kurth, W. S.

    2015-02-17

    Most theoretical wave models require the power in the wave magnetic field in order to determine the effect of chorus waves on radiation belt electrons. However, researchers typically use the cold plasma dispersion relation to approximate the magnetic wave power when only electric field data are available. In this study, the validity of using the cold plasma dispersion relation in this context is tested using Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) observations of both the electric and magnetic spectral intensities in the chorus wave band (0.1–0.9 fce). Results from this study indicate that the calculated wavemore » intensity is least accurate during periods of enhanced wave activity. For observed wave intensities >10⁻³ nT², using the cold plasma dispersion relation results in an underestimate of the wave intensity by a factor of 2 or greater 56% of the time over the full chorus wave band, 60% of the time for lower band chorus, and 59% of the time for upper band chorus. Hence, during active periods, empirical chorus wave models that are reliant on the cold plasma dispersion relation will underestimate chorus wave intensities to a significant degree, thus causing questionable calculation of wave-particle resonance effects on MeV electrons.« less

  3. Interim Project Results: United Parcel Service's Second-Generation Hybrid-Electric Delivery Vans (Fact Sheet), Vehicle Technologies Program (VTP)

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

    Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs Intergovernmental Programs The Office of Environmental Management supports, by means of grants and cooperative agreements, a number of

  4. Applying the cold plasma dispersion relation to whistler mode chorus waves: EMFISIS wave measurements from the Van Allen Probes

    SciTech Connect (OSTI)

    Hartley, D. P.; Chen, Y.; Kletzing, C. A.; Denton, M. H.; Kurth, W. S.

    2015-02-17

    Most theoretical wave models require the power in the wave magnetic field in order to determine the effect of chorus waves on radiation belt electrons. However, researchers typically use the cold plasma dispersion relation to approximate the magnetic wave power when only electric field data are available. In this study, the validity of using the cold plasma dispersion relation in this context is tested using Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) observations of both the electric and magnetic spectral intensities in the chorus wave band (0.1–0.9 fce). Results from this study indicate that the calculated wave intensity is least accurate during periods of enhanced wave activity. For observed wave intensities >10⁻³ nT², using the cold plasma dispersion relation results in an underestimate of the wave intensity by a factor of 2 or greater 56% of the time over the full chorus wave band, 60% of the time for lower band chorus, and 59% of the time for upper band chorus. Hence, during active periods, empirical chorus wave models that are reliant on the cold plasma dispersion relation will underestimate chorus wave intensities to a significant degree, thus causing questionable calculation of wave-particle resonance effects on MeV electrons.

  5. PROJECT PROFILE: CyDER: A Cyber Physical Co-simulation Platform...

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

    analysis, power generation and load forecasting, load flexibility, and real-time ... This will lead to costs below 100 for residential and below 1,000 for commercial ...

  6. Eighteen-Month Final Evaluation of UPS Second Generation Diesel...

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

    ... Motor Synchronous brushless, permanent magnet Continuous power, 26 kW Peak power, 44 kW ... Van model P100H step van P100D step van Van model year 2010 2010 Engine manufacturer and ...

  7. Twelve-Month Evaluation of UPS Diesel Hybrid Electric Delivery...

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

    ... Motor Synchronous brushless, permanent magnet Continuous power, 26 kW Peak power, 44 kW ... Van model P70H step van P70D step van Van model year 2007 2006 Engine manufacturer and ...

  8. Ionization of Rb Rydberg atoms in the attractive nsnp dipole-dipole potential

    SciTech Connect (OSTI)

    Park, Hyunwook; Shuman, E. S.; Gallagher, T. F.

    2011-11-15

    We have observed the ionization of a cold gas of Rb Rydberg atoms which occurs when nsns van der Waals pairs of ns atoms of n{approx_equal} 40 on a weakly repulsive potential are transferred to an attractive dipole-dipole nsnp potential by a microwave transition. Comparing the measurements to a simple model shows that the initial 300-{mu}K thermal velocity of the atoms plays an important role. Excitation to a repulsive dipole-dipole potential does not lead to more ionization on a 15-{mu}s time scale than leaving the atoms in the weakly repulsive nsns state. This observation is slightly surprising since a radiative transition must occur to allow ionization in the latter case. Finally, by power broadening of the microwave transition, to allow transitions from the initial nsns state to the nsnp state over a broad range of internuclear spacings, it is possible to accelerate markedly the evolution to a plasma.

  9. High Electrical Conductivity in Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2, a Semiconducting Metal-Organic Graphene Analogue

    SciTech Connect (OSTI)

    Sheberla, Dennis; Sun, Lei; Blood-Forsythe, Martin A.; Er, Süleyman; Wade, Casey R.; Brozek, Carl K.; Aspuru-Guzik, Alán; Dinc,; #259; Mircea,

    2014-09-22

    Reaction of 2,3,6,7,10,11-hexaaminotriphenylene with Ni2+ in aqueous NH3 solution under aerobic conditions produces Ni3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene), a new two-dimensional metal–organic framework (MOF). The new material can be isolated as a highly conductive black powder or dark blue-violet films. Two-probe and van der Pauw electrical measurements reveal bulk (pellet) and surface (film) conductivity values of 2 and 40 S·cm–1, respectively, both records for MOFs and among the best for any coordination polymer.

  10. (E)-2-[(2-Bromophenylimino)methyl]-5-methoxyphenol: X-ray and DFT-calculated structures

    SciTech Connect (OSTI)

    Kosar, B. Albayrak, C.; Odabasoglu, M.; Bueyuekguengoer, O.

    2010-12-15

    The crystal structure of (E)-2-[(2-Bromophenylimino)methyl]-5-methoxyphenol is determined by using X-ray diffraction and then the molecular structure is investigated with density functional theory (DFT). X-Ray study shows that the title compound has a strong intramolecular O-H-N hydrogen bond and three dimensional crystal structure is primarily determined by C-H-{pi} and weak van der Waals interactions. The strong O-H-N bond is an evidence of the preference for the phenol-imine tautomeric form in the solid state. Optimized molecular geometry is calculated with DFT at the B3LYP/6-31G(d,p) level. The IR spectra of compound were recorded experimentally and calculated to compare with each other. The results from both experiment and theoretical calculations are compared in this study.

  11. VOLATILE TRANSPORT INSIDE SUPER-EARTHS BY ENTRAPMENT IN THE WATER-ICE MATRIX

    SciTech Connect (OSTI)

    Levi, A.; Podolak, M.; Sasselov, D.

    2013-05-20

    Whether volatiles can be entrapped in a background matrix composing planetary envelopes and be dragged via convection to the surface is a key question in understanding atmospheric fluxes, cycles, and composition. In this paper, we consider super-Earths with an extensive water mantle (i.e., water planets), and the possibility of entrapment of methane in their extensive water-ice envelopes. We adopt the theory developed by van der Waals and Platteeuw for modeling solid solutions, often used for modeling clathrate hydrates, and modify it in order to estimate the thermodynamic stability field of a new phase called methane filled ice Ih. We find that in comparison to water ice VII the filled ice Ih structure may be stable not only at the high pressures but also at the high temperatures expected at the core-water mantle transition boundary of water planets.

  12. Atomically Thin Heterostructures Based on Single-Layer Tungsten Diselenide and Graphene [Plus Supplemental Information

    SciTech Connect (OSTI)

    Lin, Yu-Chuan; Chang, Chih-Yuan S.; Ghosh, Ram Krishna; Li, Jie; Zhu, Hui; Addou, Rafik; Diaconescu, Bogdan; Ohta, Taisuke; Peng, Xin; Lu, Ning; Kim, Moon J.; Robinson, Jeremy T.; Wallace, Robert M.; Mayer, Theresa S.; Datta, Suman; Li, Lain-Jong; Robinson, Joshua A.

    2014-11-10

    Heterogeneous engineering of two-dimensional layered materials, including metallic graphene and semiconducting transition metal dichalcogenides, presents an exciting opportunity to produce highly tunable electronic and optoelectronic systems. We report the direct growth of highly crystalline, monolayer tungsten diselenide (WSe2) on epitaxial graphene (EG). Raman spectroscopy and photoluminescence confirms high-quality WSe2 monolayers; while transmission electron microscopy shows an atomically sharp interface and low energy electron diffraction confirms near perfect orientation between WSe2 and EG. Vertical transport measurements across the WSe2/EG heterostructure provides evidence that a tunnel barrier exists due to the van der Waals gap, and is supported by density functional theory that predicts a 1.6 eV barrier for transport from WSe2 to graphene.

  13. Toward crystal design in organic conductors and superconductors.

    SciTech Connect (OSTI)

    Geiser, U.

    1999-04-23

    We have seen that many different types of intermolecular interactions in organic conducting cation radical salts. Hydrogen bonding between the donor molecules and the anions is weak but not negligible. The ionic Madelung energy is insufficient to completely intersperse anions and cations, thus the layers favored by the van der Waals interactions remain intact. The search for new conducting and superconducting salts has been mainly by trial-and-error methods, even though simple substitutions have been employed in order to obtain isostructural analogs of successful (e.g., superconducting) salts. However, even seemingly minor substitutions sometimes destroy the packing type, and different crystal structures result. Simulations with the aim at predicting crystal structures have not succeeded, mainly because the different interaction types are of comparable energy, and the delocalized and partial charges render the calculations of the ionic terms extremely unreliable. Clearly, the development of suitable crystal modeling techniques with predictive capabilities is one of the great needs of the field.

  14. Genomic Sequence or Signature Tags (GSTs) from the Genome Group at Brookhaven National Laboratory (BNL)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dunn, John J.; McCorkle, Sean R.; Praissman, Laura A.; Hind, Geoffrey; Van der Lelie, Daniel; Bahou, Wadie F.; Gnatenko, Dmitri V.; Krause, Maureen K.

    Genomic Signature Tags (GSTs) are the products of a method we have developed for identifying and quantitatively analyzing genomic DNAs. The DNA is initially fragmented with a type II restriction enzyme. An oligonucleotide adaptor containing a recognition site for MmeI, a type IIS restriction enzyme, is then used to release 21-bp tags from fixed positions in the DNA relative to the sites recognized by the fragmenting enzyme. These tags are PCR-amplified, purified, concatenated and then cloned and sequenced. The tag sequences and abundances are used to create a high resolution GST sequence profile of the genomic DNA. [Quoted from Genomic Signature Tags (GSTs): A System for Profiling Genomic DNA, Dunn, John J.; McCorkle, Sean R.; Praissman, Laura A.; Hind, Geoffrey; Van der Lelie, Daniel; Bahou, Wadie F.; Gnatenko, Dmitri V.; Krause, Maureen K., Revised 9/13/2002

  15. Cefic seeks energy liberalization, expects positive 1996

    SciTech Connect (OSTI)

    Alperowicz, N.

    1996-06-26

    At the recent general assembly of the European Chemical Industry Council (Cefic) in Amsterdam, president Simon de Bree urged the Council of Energy Minsters of the European Union to help boost the competitive position of the European chemical industry and other manufacturing industries. {open_quotes}The European Commission has the power to do something and could enforce electricity liberalization,{close_quotes} says Rudy van der Meer, chairman of the Dutch chemical industry association and board member of Akzo Nobel. Addressing the subject of competitiveness of the European chemical industry, de Bree, who is chairman of DSM, called for an extension of the European pipeline network, especially with multiproduct carriers. {open_quotes}These enable producers to exchange raw materials and semifinished goods on a large scale ... and strengthen [the industry`s] worldwide competitiveness.{close_quotes}

  16. Electronic structure of a superconducting topological insulator Sr-doped Bi{sub 2}Se{sub 3}

    SciTech Connect (OSTI)

    Han, C. Q.; Chen, W. J.; Zhu, Fengfeng; Yao, Meng-Yu; Li, H.; Li, Z. J.; Wang, M.; Gao, Bo F.; Guan, D. D.; Liu, Canhua; Qian, Dong Jia, Jin-Feng; Gao, C. L.

    2015-10-26

    Using high-resolution angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy, the atomic and low energy electronic structure of the Sr-doped superconducting topological insulators (Sr{sub x}Bi{sub 2}Se{sub 3}) was studied. Scanning tunneling microscopy shows that most of the Sr atoms are not in the van der Waals gap. After Sr doping, the Fermi level was found to move further upwards when compared with the parent compound Bi{sub 2}Se{sub 3}, which is consistent with the low carrier density in this system. The topological surface state was clearly observed, and the position of the Dirac point was determined in all doped samples. The surface state is well separated from the bulk conduction bands in the momentum space. The persistence of separated topological surface state combined with small Fermi energy makes this superconducting material a very promising candidate for the time reversal invariant topological superconductor.

  17. All-metallic electrically gated 2H-TaSe{sub 2} thin-film switches and logic circuits

    SciTech Connect (OSTI)

    Renteria, J.; Jiang, C.; Yan, Z.; Samnakay, R.; Goli, P.; Pope, T. R.; Salguero, T. T.; Wickramaratne, D.; Lake, R. K.; Khitun, A. G.; Balandin, A. A.

    2014-01-21

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe{sub 2} were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe{sub 2}Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

  18. Domain formation due to surface steps in topological insulator Bi{sub 2}Te{sub 3} thin films grown on Si (111) by molecular beam epitaxy

    SciTech Connect (OSTI)

    Borisova, S.; Kampmeier, J.; Mussler, G.; Grützmacher, D.; Jülich Aachen Research Alliance, Fundamentals of Future Information Technologies, Jülich 52425 ; Luysberg, M.

    2013-08-19

    The atomic structure of topological insulators Bi{sub 2}Te{sub 3} thin films on Si (111) substrates grown in van der Waals mode by molecular beam epitaxy has been investigated by in situ scanning tunneling microscopy and scanning transmission electron microscopy. Besides single and multiple quintuple layer (QL) steps, which are typical for the step-flow mode of growth, a number of 0.4 QL steps is observed. We determine that these steps originate from single steps at the substrate surface causing domain boundaries in the Bi{sub 2}Te{sub 3} film. Due to the peculiar structure of these domain boundaries the domains are stable and penetrate throughout the entire film.

  19. Anion separation with metal-organic frameworks

    SciTech Connect (OSTI)

    Custelcean, Radu; Moyer, Bruce A

    2007-01-01

    The application of metal-organic frameworks (MOFs) to anion separations with a special emphasis on anion selectivity is reviewed. The coordination frameworks are classified on the basis of the main interactions to the included anion, from weak and non-specific van der Waals forces to more specific interactions such as coordination to Lewis acid metal centers or hydrogen bonding. The importance of anion solvation phenomena to the observed anion selectivities is highlighted, and strategies for reversing the Hofmeister bias that favors large, less hydrophilic anions, and for obtaining peak selectivities based on shape recognition are delineated. Functionalization of the anion-binding sites in MOFs with strong and directional hydrogen-bonding groups that are complementary to the included anion, combined with organizational rigidity of the coordination framework, appears to be the most promising approach for achieving non-Hofmeister selectivity.

  20. Kinetic, Spectroscopic, and Theoretical Assessment of Associative and Dissociative Methanol Dehydration Routes in Zeolites

    SciTech Connect (OSTI)

    Jones, Andrew J.; Iglesia, Enrique

    2014-11-03

    Mechanistic interpretations of rates and in situ IR spectra combined with density functionals that account for van der Waals interactions of intermediates and transition states within confining voids show that associative routes mediate the formation of dimethyl ether from methanol on zeolitic acids at the temperatures and pressures of practical dehydration catalysis. Methoxy-mediated dissociative routes become prevalent at higher temperatures and lower pressures, because they involve smaller transition states with higher enthalpy, but also higher entropy, than those in associative routes. These enthalpyentropy trade-offs merely reflect the intervening role of temperature in activation free energies and the prevalence of more complex transition states at low temperatures and high pressures. This work provides a foundation for further inquiry into the contributions of H-bonded methanol and methoxy species in homologation and hydrocarbon synthesis reactions from methanol.

  1. Thermoelectric properties of nano-meso-micro β-MnO₂ powders as a function of electrical resistance

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

    Hedden, Morgan; Francis, Nick; Haraldsen, Jason T.; Ahmed, Towfiq; Constantin, Costel

    2015-07-15

    Particle sizes of manganese oxide (β-MnO₂) powders were modified by using a mortar and pestle ground method for period of times that varied between 15–60 min. Particle size versus ground time clearly shows the existence of a size-induced regime transition (i.e., regime I and II). Thermoelectric properties of β-MnO₂ powders as a function of electrical resistance in the range of RP = 10 - 80Ω were measured. Based on the data presented, we propose a model for the β-MnO₂ system in which nanometer-scale MnO₂ crystallites bond together through weak van der Waals forces to form larger conglomerates that span inmore » size from nanometer to micrometer scale.« less

  2. Antisite Defects in Layered Multiferroic CuCr0.9In0.1P2S6

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

    He, Qian; Belianinov, Alex; Dziaugys, Andrius; Maksymovych, Petro; Vysochanskii, Yulian; Kalinin, Sergei V.; Borisevich, Albina Y.

    2015-10-06

    The CuCr1-xInxP2S6 system represents a large family of metal chalcogenophosphates that are unique and promising candidates for 2D materials with functionalities such as ferroelectricity. We carried out detailed microstructural and chemical characterization of these compounds using aberration-corrected STEM, in order to understand the origin of these different ordering phenomena. Quantitative STEM-HAADF imaging and analysis identified the stacking order of an 8-layer thin flake, which leads to the identification of anti-site In3+(Cu+) doping. We believe that these findings will pave the way towards understanding the ferroic coupling phenomena in van der Waals lamellar compounds, as well as the potential applications inmore » 2-D electronics.« less

  3. Stacking interactions and DNA intercalation

    SciTech Connect (OSTI)

    Li, Dr. Shen; Cooper, Valentino R; Thonhauser, Prof. Timo; Lundqvist, Prof. Bengt I.; Langreth, David C.

    2009-01-01

    The relationship between stacking interactions and the intercalation of proflavine and ellipticine within DNA is investigated using a nonempirical van der Waals density functional for the correlation energy. Our results, employing a binary stack model, highlight fundamental, qualitative differences between base-pair base-pair interactions and that of the stacked intercalator base pair system. Most notable result is the paucity of torque which so distinctively defines the Twist of DNA. Surprisingly, this model, when combined with a constraint on the twist of the surrounding base-pair steps to match the observed unwinding of the sugar-phosphate backbone, was sufficient for explaining the experimentally observed proflavine intercalator configuration. Our extensive mapping of the potential energy surface of base-pair intercalator interactions can provide valuable information for future nonempirical studies of DNA intercalation dynamics.

  4. Graphene folding on flat substrates

    SciTech Connect (OSTI)

    Chen, Xiaoming; Zhao, Yadong; Ke, Changhong; Zhang, Liuyang; Wang, Xianqiao

    2014-10-28

    We present a combined experimental-theoretical study of graphene folding on flat substrates. The structure and deformation of the folded graphene sheet are experimentally characterized by atomic force microscopy. The local graphene folding behaviors are interpreted based on nonlinear continuum mechanics modeling and molecular dynamics simulations. Our study on self-folding of a trilayer graphene sheet reports a bending stiffness of about 6.57?eV, which is about four times the reported values for monolayer graphene. Our results reveal that an intriguing free sliding phenomenon occurs at the interlayer van der Waals interfaces during the graphene folding process. This work demonstrates that it is a plausible venue to quantify the bending stiffness of graphene based on its self-folding conformation on flat substrates. The findings reported in this work are useful to a better understanding of the mechanical properties of graphene and in the pursuit of its applications.

  5. Fourier-transform microwave spectroscopy and determination of the three dimensional potential energy surface for ArCS

    SciTech Connect (OSTI)

    Niida, Chisato; Nakajima, Masakazu; Endo, Yasuki; Sumiyoshi, Yoshihiro; Ohshima, Yasuhiro; Kohguchi, Hiroshi

    2014-03-14

    Pure rotational transitions of the ArCS van der Waals complex have been observed by Fourier Transform Microwave (FTMW) and FTMW-millimeter wave double resonance spectroscopy. Rotational transitions of v{sub s} = 0, 1, and 2 were able to be observed for normal CS, together with those of C{sup 34}S in v{sub s} = 0, where v{sub s} stands for the quantum number of the CS stretching vibration. The observed transition frequencies were analyzed by a free rotor model Hamiltonian, where rovibrational energies were calculated as dynamical motions of the three nuclei on a three-dimensional potential energy surface, expressed by analytical functions with 57 parameters. Initial values for the potential parameters were obtained by high-level ab initio calculations. Fifteen parameters were adjusted among the 57 parameters to reproduce all the observed transition frequencies with the standard deviation of the fit to be 0.028 MHz.

  6. Studies of ground-state dynamics in isolated species by ionization-detected stimulated Raman techniques

    SciTech Connect (OSTI)

    Felker, P.M.

    1993-12-01

    First, the author aims to develop methods of nonlinear Raman spectroscopy for application in studies of sparse samples. Second, the author wishes to apply such methods to structural and dynamical studies of species (molecules, complexes, and clusters) in supersonic molecular beams. In the past year, the author has made progress in several areas. The first pertains to the application of mass-selective ionization-detected stimulated Raman spectroscopies (IDSRS) to the size-specific vibrational spectroscopy of solute-solvent{sub n} clusters. The second involves the application of IDSRS methods to studies of jet-cooled benzene clusters. The third pertains to the use of IDSRS methods in the study of intermolecular vibrational transitions in van der Waals complexes.

  7. Dynamics of synchrotron VUV-induced intracluster reactions

    SciTech Connect (OSTI)

    Grover, J.R.

    1993-12-01

    Photoionization mass spectrometry (PIMS) using the tunable vacuum ultraviolet radiation available at the National Synchrotron Light Source is being exploited to study photoionization-induced reactions in small van der Waals mixed complexes. The information gained includes the observation and classification of reaction paths, the measurement of onsets, and the determination of relative yields of competing reactions. Additional information is obtained by comparison of the properties of different reacting systems. Special attention is given to finding unexpected features, and most of the reactions investigated to date display such features. However, understanding these reactions demands dynamical information, in addition to what is provided by PIMS. Therefore the program has been expanded to include the measurement of kinetic energy release distributions.

  8. Ternary metal-rich sulfide with a layered structure

    DOE Patents [OSTI]

    Franzen, Hugo F.; Yao, Xiaoqiang

    1993-08-17

    A ternary Nb-Ta-S compound is provided having the atomic formula, Nb.sub.1.72 Ta.sub.3.28 S.sub.2, and exhibiting a layered structure in the sequence S-M3-M2-M1-M2-M3-S wherein S represents sulfur layers and M1, M2, and M3 represent Nb/Ta mixed metal layers. This sequence generates seven sheets stacked along the [001] direction of an approximate body centered cubic crystal structure with relatively weak sulfur-to-sulfur van der Waals type interactions between adjacent sulfur sheets and metal-to-metal bonding within and between adjacent mixed metal sheets.

  9. Atomically Thin Heterostructures Based on Single-Layer Tungsten Diselenide and Graphene [Plus Supplemental Information

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

    Lin, Yu-Chuan; Chang, Chih-Yuan S.; Ghosh, Ram Krishna; Li, Jie; Zhu, Hui; Addou, Rafik; Diaconescu, Bogdan; Ohta, Taisuke; Peng, Xin; Lu, Ning; et al

    2014-11-10

    Heterogeneous engineering of two-dimensional layered materials, including metallic graphene and semiconducting transition metal dichalcogenides, presents an exciting opportunity to produce highly tunable electronic and optoelectronic systems. We report the direct growth of highly crystalline, monolayer tungsten diselenide (WSe2) on epitaxial graphene (EG). Raman spectroscopy and photoluminescence confirms high-quality WSe2 monolayers; while transmission electron microscopy shows an atomically sharp interface and low energy electron diffraction confirms near perfect orientation between WSe2 and EG. Vertical transport measurements across the WSe2/EG heterostructure provides evidence that a tunnel barrier exists due to the van der Waals gap, and is supported by density functional theorymore » that predicts a 1.6 eV barrier for transport from WSe2 to graphene.« less

  10. Bonded semiconductor substrate

    DOE Patents [OSTI]

    Atwater, Jr.; Harry A. , Zahler; James M.

    2010-07-13

    Ge/Si and other nonsilicon film heterostructures are formed by hydrogen-induced exfoliation of the Ge film which is wafer bonded to a cheaper substrate, such as Si. A thin, single-crystal layer of Ge is transferred to Si substrate. The bond at the interface of the Ge/Si heterostructures is covalent to ensure good thermal contact, mechanical strength, and to enable the formation of an ohmic contact between the Si substrate and Ge layers. To accomplish this type of bond, hydrophobic wafer bonding is used, because as the invention demonstrates the hydrogen-surface-terminating species that facilitate van der Waals bonding evolves at temperatures above 600.degree. C. into covalent bonding in hydrophobically bound Ge/Si layer transferred systems.

  11. Method of using a germanium layer transfer to Si for photovoltaic applications and heterostructure made thereby

    DOE Patents [OSTI]

    Atwater, Jr., Harry A.; Zahler, James M.

    2006-11-28

    Ge/Si and other nonsilicon film heterostructures are formed by hydrogen-induced exfoliation of the Ge film which is wafer bonded to a cheaper substrate, such as Si. A thin, single-crystal layer of Ge is transferred to Si substrate. The bond at the interface of the Ge/Si heterostructures is covalent to ensure good thermal contact, mechanical strength, and to enable the formation of an ohmic contact between the Si substrate and Ge layers. To accomplish this type of bond, hydrophobic wafer bonding is used, because as the invention demonstrates the hydrogen-surface-terminating species that facilitate van der Waals bonding evolves at temperatures above 600.degree. C. into covalent bonding in hydrophobically bound Ge/Si layer transferred systems.

  12. Improved Potential Energy Surface of Ozone Constructed Using the Fitting by Permutationally Invariant Polynomial Function

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

    Ayouz, Mehdi; Babikov, Dmitri

    2012-01-01

    New global potential energy surface for the ground electronic state of ozone is constructed at the complete basis set level of the multireference configuration interaction theory. A method of fitting the data points by analytical permutationally invariant polynomial function is adopted. A small set of 500 points is preoptimized using the old surface of ozone. In this procedure the positions of points in the configuration space are chosen such that the RMS deviation of the fit is minimized. New ab initio calculations are carried out at these points and are used to build new surface. Additional points are addedmore » to the vicinity of the minimum energy path in order to improve accuracy of the fit, particularly in the region where the surface of ozone exhibits a shallow van der Waals well. New surface can be used to study formation of ozone at thermal energies and its spectroscopy near the dissociation threshold.« less

  13. Mechanical strength of boron nitride nanotube-polymer interfaces

    SciTech Connect (OSTI)

    Chen, Xiaoming; Ke, Changhong E-mail: cke@binghamton.edu; Zhang, Liuyang; Wang, Xianqiao E-mail: cke@binghamton.edu; Park, Cheol; Fay, Catharine C.

    2015-12-21

    We investigate the mechanical strength of boron nitride nanotube (BNNT) polymer interfaces by using in situ electron microscopy nanomechanical single-tube pull-out techniques. The nanomechanical measurements show that the shear strengths of BNNT-epoxy and BNNT-poly(methyl methacrylate) interfaces reach 323 and 219 MPa, respectively. Molecular dynamics simulations reveal that the superior load transfer capacity of BNNT-polymer interfaces is ascribed to both the strong van der Waals interactions and Coulomb interactions on BNNT-polymer interfaces. The findings of the extraordinary mechanical strength of BNNT-polymer interfaces suggest that BNNTs are excellent reinforcing nanofiller materials for light-weight and high-strength polymer nanocomposites.

  14. Energy level alignment of self-assembled linear chains of benzenediamine on Au(111) from first principles

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

    Li, Guo; Rangel, Tonatiuh; Liu, Zhen -Fei; Cooper, Valentino R.; Neaton, Jeffrey B.

    2016-03-24

    Using density functional theory (DFT) with van der Waals functionals, we calculate the adsorption energetics and geometry of benzenediamine (BDA) molecules on Au(111) surfaces. Our results demonstrate that the reported self-assembled linear chain structure of BDA, stabilized via hydrogen bonds between amine groups, is energetically favored over previously-studied monomeric phases. Moreover, using a model based on many-body perturbation theory within the GW approximation, we obtain approximate self-energy corrections to the DFT highest occupied molecular orbital (HOMO) energy associated with BDA adsorbate phases. As a result, we find that, independent of coverage, the HOMO energy of the linear chain phase ismore » lower relative to the Fermi energy than that of the monomer phase, and in good agreement with values measured with ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy.« less

  15. Semiconductor Nanostructures By Scientific Design

    SciTech Connect (OSTI)

    Galli, Guilia

    2015-02-12

    The goals and objectives of the present proposal are very much aligned with those of the previous award cycle. In the last three years we investigated semiconducting nanoparticles, nanowires and nanocomposites to understand and optimize their optical properties for solar applications and their heat transport properties for thermoelectric applications. We focused on understanding the role of surfaces and interfaces; our study included the investigation of surfactants, in particular of the role of van der Waals forces in binding surfactants to specific substrates. In addition to addressing specific nanoscience and materials science problems, we developed techniques and codes of general applicability. The investigations carried out in the past three years have resulted in 10 published papers in peer reviewed journals (including NL, ACS Nano and PRL) and in 3 papers submitted for publication in 2012 (now appeared).

  16. Dynamic density functional theory with hydrodynamic interactions: Theoretical development and application in the study of phase separation in gas-liquid systems

    SciTech Connect (OSTI)

    Kikkinides, E. S.; Monson, P. A.

    2015-03-07

    Building on recent developments in dynamic density functional theory, we have developed a version of the theory that includes hydrodynamic interactions. This is achieved by combining the continuity and momentum equations eliminating velocity fields, so the resulting model equation contains only terms related to the fluid density and its time and spatial derivatives. The new model satisfies simultaneously continuity and momentum equations under the assumptions of constant dynamic or kinematic viscosity and small velocities and/or density gradients. We present applications of the theory to spinodal decomposition of subcritical temperatures for one-dimensional and three-dimensional density perturbations for both a van der Waals fluid and for a lattice gas model in mean field theory. In the latter case, the theory provides a hydrodynamic extension to the recently studied dynamic mean field theory. We find that the theory correctly describes the transition from diffusive phase separation at short times to hydrodynamic behaviour at long times.

  17. Theoretical analysis of sound transmission loss through graphene sheets

    SciTech Connect (OSTI)

    Natsuki, Toshiaki; Ni, Qing-Qing

    2014-11-17

    We examine the potential of using graphene sheets (GSs) as sound insulating materials that can be used for nano-devices because of their small size, super electronic, and mechanical properties. In this study, a theoretical analysis is proposed to predict the sound transmission loss through multi-layered GSs, which are formed by stacks of GS and bound together by van der Waals (vdW) forces between individual layers. The result shows that the resonant frequencies of the sound transmission loss occur in the multi-layered GSs and the values are very high. Based on the present analytical solution, we predict the acoustic insulation property for various layers of sheets under both normal incident wave and acoustic field of random incidence source. The scheme could be useful in vibration absorption application of nano devices and materials.

  18. Theory of melting at high pressures: Amending density functional theory with quantum Monte Carlo

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

    Shulenburger, L.; Desjarlais, M. P.; Mattsson, T. R.

    2014-10-01

    We present an improved first-principles description of melting under pressure based on thermodynamic integration comparing Density Functional Theory (DFT) and quantum Monte Carlo (QMC) treatments of the system. The method is applied to address the longstanding discrepancy between density functional theory (DFT) calculations and diamond anvil cell (DAC) experiments on the melting curve of xenon, a noble gas solid where van der Waals binding is challenging for traditional DFT methods. The calculations show excellent agreement with data below 20 GPa and that the high-pressure melt curve is well described by a Lindemann behavior up to at least 80 GPa, amore » finding in stark contrast to DAC data.« less

  19. On the kinetic barriers of graphene homo-epitaxy

    SciTech Connect (OSTI)

    Zhang, Wei; Yu, Xinke; Xie, Ya-Hong; Cahyadi, Erica; Ratsch, Christian

    2014-12-01

    The diffusion processes and kinetic barriers of individual carbon adatoms and clusters on graphene surfaces are investigated to provide fundamental understanding of the physics governing epitaxial growth of multilayer graphene. It is found that individual carbon adatoms form bonds with the underlying graphene whereas the interaction between graphene and carbon clusters, consisting of 6 atoms or more, is very weak being van der Waals in nature. Therefore, small carbon clusters are quite mobile on the graphene surfaces and the diffusion barrier is negligibly small (?6?meV). This suggests the feasibility of high-quality graphene epitaxial growth at very low growth temperatures with small carbon clusters (e.g., hexagons) as carbon source. We propose that the growth mode is totally different from 3-dimensional bulk materials with the surface mobility of carbon hexagons being the highest over graphene surfaces that gradually decreases with further increase in cluster size.

  20. Benchmarking exchange-correlation functionals for hydrogen at high pressures using quantum Monte Carlo

    SciTech Connect (OSTI)

    Clay, Raymond C.; Mcminis, Jeremy; McMahon, Jeffrey M.; Pierleoni, Carlo; Ceperley, David M.; Morales, Miguel A.

    2014-05-01

    The ab initio phase diagram of dense hydrogen is very sensitive to errors in the treatment of electronic correlation. Recently, it has been shown that the choice of the density functional has a large effect on the predicted location of both the liquid-liquid phase transition and the solid insulator-to-metal transition in dense hydrogen. To identify the most accurate functional for dense hydrogen applications, we systematically benchmark some of the most commonly used functionals using quantum Monte Carlo. By considering several measures of functional accuracy, we conclude that the van der Waals and hybrid functionals significantly outperform local density approximation and Perdew-Burke-Ernzerhof. We support these conclusions by analyzing the impact of functional choice on structural optimization in the molecular solid, and on the location of the liquid-liquid phase transition.

  1. Linear relationship between water wetting behavior and microscopic interactions of super-hydrophilic surfaces

    SciTech Connect (OSTI)

    Liu, Jian; Guo, Pan; University of Chinese Academy of Sciences, Beijing 100049 ; Wang, Chunlei; Shi, Guosheng Fang, Haiping

    2013-12-21

    Using molecular dynamics simulations, we show a fine linear relationship between surface energies and microscopic Lennard-Jones parameters of super-hydrophilic surfaces. The linear slope of the super-hydrophilic surfaces is consistent with the linear slope of the super-hydrophobic, hydrophobic, and hydrophilic surfaces where stable water droplets can stand, indicating that there is a universal linear behavior of the surface energies with the water-surface van der Waals interaction that extends from the super-hydrophobic to super-hydrophilic surfaces. Moreover, we find that the linear relationship exists for various substrate types, and the linear slopes of these different types of substrates are dependent on the surface atom density, i.e., higher surface atom densities correspond to larger linear slopes. These results enrich our understanding of water behavior on solid surfaces, especially the water wetting behaviors on uncharged super-hydrophilic metal surfaces.

  2. Structural study of Ni- or Mg-based complexes incorporated within UiO-66-NH{sub 2} framework and their impact on hydrogen sorption properties

    SciTech Connect (OSTI)

    Žunkovič, E.; Mazaj, M.; Mali, G.; Rangus, M.; Devic, T.; Serre, C.; Logar, N. Zabukovec

    2015-05-15

    Nickel and magnesium acetylacetonate molecular complexes were post-synthetically incorporated into microporous zirconium-based MOF (UiO-66-NH{sub 2}) in order to introduce active open-metal sites for hydrogen sorption. Elemental analysis, nitrogen physisorption and DFT calculations revealed that 5 molecules of Ni(acac){sub 2} or 2 molecules of Mg(acac){sub 2} were incorporated into one unit cell of UiO-66-NH{sub 2}. {sup 1}H–{sup 13}C CPMAS and {sup 1}H MAS NMR spectroscopy showed that, although embedded within the pores, both Ni- and Mg-complexes interacted with the UiO-66-NH{sub 2} framework only through weak van der Waals bonds. Inclusion of metal complexes led to the decrease of hydrogen sorption capacities in Ni-modified as well as in Mg-modified samples in comparison with the parent UiO-66-NH{sub 2}. The isosteric hydrogen adsorption enthalpy slightly increased in the case of Ni-modified material, but not in the case of Mg-modified analogue. - Graphical abstract: A post-synthesis impregnation of Mg- and Ni-acetylacetonate complexes performed on zirconium-based MOF UiO-66-NH{sub 2} does influence the hydrogen sorption performance with respect to the parent matrix. The structural study revealed that Mg- and Ni-acetylacetonate molecules interact with zirconium-terephthalate framework only by weak interactions and they are not covalently bonded to aminoterephthalate ligand. Still, they remain confined into the pores even after hydrogen sorption experiments. - Highlights: • Mg- and Ni-acetylacetonate molecules embedded in the pores of UiO-66-NH{sub 2} by PSM. • Molecules of complexes interact with framework only by van der Waals interactions. • Type/structure of deposited metal-complex impact hydrogen enthalpy of adsorption.

  3. Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

    SciTech Connect (OSTI)

    Al-Hamdani, Yasmine S.; Michaelides, Angelos; Alf, Dario; Lilienfeld, O. Anatole von

    2014-11-14

    Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we show that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B{sub 3}N{sub 3}H{sub 6}) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.

  4. Enantioselectivity of (321) chiral noble metal surfaces: A density functional theory study of lactate adsorption

    SciTech Connect (OSTI)

    Franke, J.-H.; Kosov, D. S.

    2013-12-14

    The adsorption of the chiral molecule lactate on the intrinsically chiral noble metal surfaces Pt(321), Au(321), and Ag(321) is studied by density functional theory calculations. We use the oPBE-vdW functional which includes van der Waals forces on an ab initio level. It is shown that the molecule binds via its carboxyl and the hydroxyl oxygen atoms to the surface. The binding energy is larger on Pt(321) and Ag(321) than on Au(321). An analysis of the contributions to the binding energy of the different molecular functional groups reveals that the deprotonated carboxyl group contributes most to the binding energy, with a much smaller contribution of the hydroxyl group. The Pt(321) surface shows considerable enantioselectivity of 0.06 eV. On Au(321) and Ag(321) it is much smaller if not vanishing. The chiral selectivity of the Pt(321) surface can be explained by two factors. First, it derives from the difference in van der Waals attraction of L- and D-lactate to the surface that we trace to differences in the binding energy of the methyl group. Second, the multi-point binding pattern for lactate on the Pt(321) surface is sterically more sensitive to surface chirality and also leads to large binding energy contributions of the hydroxyl group. We also calculate the charge transfer to the molecule and the work function to gauge changes in electronic structure of the adsorbed molecule. The work function is lowered by 0.8 eV on Pt(321) with much smaller changes on Au(321) and Ag(321)

  5. Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

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

    Al-Hamdani, Yasmine S.; Alfè, Dario; von Lilienfeld, O. Anatole; Michaelides, Angelos

    2014-10-22

    Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we showmore » that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B₃N₃H₆) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.« less

  6. Study of radicals, clusters and transition state species by anion photoelectron spectroscopy

    SciTech Connect (OSTI)

    Arnold, D.W.

    1994-08-01

    Free radicals, elemental and van der Waals clusters and transition state species for bimolecular chemical reactions are investigated using anion photoelectron spectroscopy. Several low-lying electronic states of ozone have been identified via photoelectron spectroscopy of O{sub 3}{sup {minus}}. A characterization of these states is important to models for atmospheric ozone reaction kinetics. The fluoroformyloxyl radical, FCO{sub 2}, has been investigated, providing vibrational frequencies and energies for two electronic states. The technique has also been employed to make the first direct observation and characterization of the NNO{sub 2} molecule. Several electronic states are observed for this species which is believed to play a role as a reactive intermediate in the N + NO{sub 2} reaction. The experimental results for all three of these radicals are supplemented by ab initio investigations of their molecular properties. The clusters investigations include studies of elemental carbon clusters (C{sub 2}{sup {minus}} {minus} C{sub 11}{sup {minus}}), and van der Waals clusters (X{sup {minus}}(CO{sub 2}){sub n}, X = I, Br, Cl; n {le} 13 and I{sup {minus}} (N{sub 2}O){sub n=1--11}). Primarily linear clusters are observed for the smaller carbon clusters, while the spectra of the larger clusters contain contribution from cyclic anion photodetachment. Very interesting ion-solvent interactions are observed in the X{sup {minus}}(CO{sub 2})n clusters. The transition state regions for several bimolecular chemical reactions have also been investigated by photodetachment of a negative ion precursor possessing a geometry similar to that of the transition state species. These spectra show features which are assigned to motions of the unstable neutral complex existing between reactants and products.

  7. United polarizable multipole water model for molecular mechanics simulation

    SciTech Connect (OSTI)

    Qi, Rui; Wang, Qiantao; Ren, Pengyu; Wang, Lee-Ping; Pande, Vijay S.

    2015-07-07

    We report the development of a united AMOEBA (uAMOEBA) polarizable water model, which is computationally 3–5 times more efficient than the three-site AMOEBA03 model in molecular dynamics simulations while providing comparable accuracy for gas-phase and liquid properties. In this coarse-grained polarizable water model, both electrostatic (permanent and induced) and van der Waals representations have been reduced to a single site located at the oxygen atom. The permanent charge distribution is described via the molecular dipole and quadrupole moments and the many-body polarization via an isotropic molecular polarizability, all located at the oxygen center. Similarly, a single van der Waals interaction site is used for each water molecule. Hydrogen atoms are retained only for the purpose of defining local frames for the molecular multipole moments and intramolecular vibrational modes. The parameters have been derived based on a combination of ab initio quantum mechanical and experimental data set containing gas-phase cluster structures and energies, and liquid thermodynamic properties. For validation, additional properties including dimer interaction energy, liquid structures, self-diffusion coefficient, and shear viscosity have been evaluated. The results demonstrate good transferability from the gas to the liquid phase over a wide range of temperatures, and from nonpolar to polar environments, due to the presence of molecular polarizability. The water coordination, hydrogen-bonding structure, and dynamic properties given by uAMOEBA are similar to those derived from the all-atom AMOEBA03 model and experiments. Thus, the current model is an accurate and efficient alternative for modeling water.

  8. Rewetting of a low superheated rod with saturated water

    SciTech Connect (OSTI)

    Portillo, O.; Reyes, R.; Wayner, P.C. Jr.

    1999-07-01

    The study of the rewetting of a superheated surface has application in several technological fields. It is related to the control mechanism for loss of coolant accident (LOCA) in nuclear reactors. An adsorption model as the precursory mechanism for rewetting of a superheated surface is extended from its application to non-polar liquids to a polar fluid, and modeling calculations are compared with experimental data found in the literature. The adsorption model is based on interfacial forces acting at the tip of the rewetting front, the three-phase region. In this region, solid, liquid and vapor interfaces generate a contact angle that depends on the degree of superheat and describes the velocity of rewetting. The contact angle is a function of interfacial forces calculated through the disjoining pressure of the adsorbed film precursory of the rewetting. The influences of van der Waals and electrostatic intermolecular forces in the film thickness are analyzed. The authors find that the order of magnitude of the film thickness in the controlling region is of a few angstroms: thus, only van der Waals intermolecular forces define the interactions. For the prediction of the velocity of rewetting the temperature profile along the rod's surface is required and a one-dimensional and a two-dimensional heat conduction balances are solved. The thermophysical properties in the adsorption model are predicted by ASPEN PLUS data bank and from ASME steam tables. Variations of the predicted values have a strong influence on the results. The surface boundary condition on the rod contains an evaporative heat transfer coefficient that is calculated from the fitted experimental rewetting velocities and the two-dimensional temperature field in the rod. Using this calculation scheme the values of the evaporative heat transfer coefficient are obtained in the normal range of values. Therefore the adsorption model gives results that are consistent with experimental observations.

  9. Control of Greenhouse Gas Emissions by Optimal DER Technology Investment and Energy Management in Zero-Net-Energy Buildings

    SciTech Connect (OSTI)

    Stadler, Michael; Siddiqui, Afzal; Marnay, Chris; Aki, Hirohisa; Lai, Judy

    2009-08-10

    The U.S. Department of Energy has launched the commercial building initiative (CBI) in pursuit of its research goal of achieving zero-net-energy commercial buildings (ZNEB), i.e. ones that produce as much energy as they use. Its objective is to make these buildings marketable by 2025 such that they minimize their energy use through cutting-edge, energy-efficiency technologies and meet their remaining energy needs through on-site renewable energy generation. This paper examines how such buildings may be implemented within the context of a cost- or CO2-minimizing microgrid that is able to adopt and operate various technologies: photovoltaic modules (PV) and other on-site generation, heat exchangers, solar thermal collectors, absorption chillers, and passive/demand-response technologies. A mixed-integer linear program (MILP) that has a multi-criteria objective function is used. The objective is minimization of a weighted average of the building's annual energy costs and CO2 emissions. The MILP's constraints ensure energy balance and capacity limits. In addition, constraining the building's energy consumed to equal its energy exports enables us to explore how energy sales and demand-response measures may enable compliance with the ZNEB objective. Using a commercial test site in northernCalifornia with existing tariff rates and technology data, we find that a ZNEB requires ample PV capacity installed to ensure electricity sales during the day. This is complemented by investment in energy-efficient combined heat and power (CHP) equipment, while occasional demand response shaves energy consumption. A large amount of storage is also adopted, which may be impractical. Nevertheless, it shows the nature of the solutions and costs necessary to achieve a ZNEB. Additionally, the ZNEB approach does not necessary lead to zero-carbon (ZC) buildings as is frequently argued. We also show a multi-objective frontier for the CA example, whichallows us to estimate the needed technologies and costs for achieving a ZC building or microgrid.

  10. Kinetics of Slurry Phase Fischer-Tropsch Synthesis

    SciTech Connect (OSTI)

    Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski; Lech Nowicki; Madhav Nayapati

    2006-12-31

    The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. Three STSR tests of the Ruhrchemie LP 33/81 catalyst were conducted to collect data on catalyst activity and selectivity under 25 different sets of process conditions. The observed decrease in 1-olefin content and increase in 2-olefin and n-paraffin contents with the increase in conversion are consistent with a concept that 1-olefins participate in secondary reactions (e.g. 1-olefin hydrogenation, isomerization and readsorption), whereas 2-olefins and n-paraffins are formed in these reactions. Carbon number product distribution showed an increase in chain growth probability with increase in chain length. Vapor-liquid equilibrium calculations were made to check validity of the assumption that the gas and liquid phases are in equilibrium during FTS in the STSR. Calculated vapor phase compositions were in excellent agreement with experimental values from the STSR under reaction conditions. Discrepancies between the calculated and experimental values for the liquid-phase composition (for some of the experimental data) are ascribed to experimental errors in the amount of wax collected from the reactor, and the relative amounts of hydrocarbon wax and Durasyn 164 oil (start-up fluid) in the liquid samples. Kinetic parameters of four kinetic models (Lox and Froment, 1993b; Yang et al., 2003; Van der Laan and Beenackers, 1998, 1999; and an extended kinetic model of Van der Laan and Beenackers) were estimated from experimental data in the STSR tests. Two of these kinetic models (Lox and Froment, 1993b; Yang et al., 2003) can predict a complete product distribution (inorganic species and hydrocarbons), whereas the kinetic model of Van der Laan and Beenackers (1998, 1999) can

  11. Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Vans Renzenberger Inc Saves Money With Propane Vans to someone by E-mail Share Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane Vans on Facebook Tweet about Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane Vans on Twitter Bookmark Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane Vans on Google Bookmark Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane Vans on Delicious Rank Alternative Fuels Data

  12. Spacecraft surface charging within geosynchronous orbit observed...

    Office of Scientific and Technical Information (OSTI)

    Title: Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes: SPACECRAFT CHARGING ON VAN ALLEN PROBES Authors: Sarno-Smith, Lois K. 1 ; Larsen, ...

  13. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes: SPACECRAFT CHARGING ON VAN ALLEN PROBES Sarno-Smith, Lois K. ; Larsen, Brian A. ; Skoug, ...

  14. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    ... Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes: SPACECRAFT CHARGING ON VAN ALLEN PROBES Sarno-Smith, Lois K. ; Larsen, Brian A. ; Skoug, ...

  15. Browse by Discipline -- E-print Network Subject Pathways: Mathematics...

    Office of Scientific and Technical Information (OSTI)

    W X Y Z Van Zee, John W. (John W. Van Zee) - Department of Chemical Engineering, University of South Carolina Varaiya, Pravin (Pravin Varaiya) - Department of Electrical ...

  16. Preparation of Papers for AIAA Technical Conferences

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

    , Albuquerque, NM, 87185 Jeroen van Dam and Scott Hughes National Renewable ... 20 Adams, D.; White, J.; Rumsey, M.; van Dam, J., "Impact, Loading and Damage Detection ...

  17. Browse by Discipline -- E-print Network Subject Pathways: Geosciences...

    Office of Scientific and Technical Information (OSTI)

    Van Duyne, Richard P.(Richard P.Van Duyne).- Department of Chemistry, Northwestern University Vardi, Amichay (Amichay Vardi) - Department of Chemistry, Ben-Gurion University Velev, ...

  18. Near-earth injection of MeV electrons associated with intense...

    Office of Scientific and Technical Information (OSTI)

    Van Allen Probes observations Citation Details In-Document Search Title: Near-earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen ...

  19. OSTIblog Articles in the space technology Topic | OSTI, US Dept...

    Office of Scientific and Technical Information (OSTI)

    space technology Topic James Van Allen - Space Pioneer by Kathy Chambers 10 Jun, 2016 in jamesvanallenwcaption.jpg James Van Allen's space instrumentation innovations and his... ...

  20. KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

    SciTech Connect (OSTI)

    Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski

    2006-09-29

    This report covers the fourth year of a research project conducted under the University Coal Research Program. The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict molar flow rates and concentrations of all reactants and major product species (water, carbon dioxide, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the fourth year of the project, an analysis of experimental data collected during the second year of this project was performed. Kinetic parameters were estimated utilizing product distributions from 27 mass balances. During the reporting period two kinetic models were employed: a comprehensive kinetic model of Dr. Li and co-workers (Yang et al., 2003) and a hydrocarbon selectivity model of Van der Laan and Beenackers (1998, 1999) The kinetic model of Yang et al. (2003) has 24 parameters (20 parameters for hydrocarbon formation, and 4 parameters for the water-gas-shift (WGS) reaction). Kinetic parameters for the WGS reaction and FTS synthesis were estimated first separately, and then simultaneously. The estimation of these kinetic parameters employed the Levenberg-Marquardt (LM) method and the trust-region reflective Newton large-scale (LS) method. A genetic algorithm (GA) was incorporated into estimation of parameters for FTS reaction to provide initial estimates of model parameters. All reaction rate constants and activation energies were found to be positive, but at the 95% confidence level the intervals were large. Agreement between predicted and experimental reaction rates has been fair to good. Light hydrocarbons are predicted fairly accurately, whereas the model underpredicts values of higher molecular weight

  1. Intercalation of organic molecules into SnS{sub 2} single crystals

    SciTech Connect (OSTI)

    Toh, M.L.; Tan, K.J.; Wei, F.X.; Zhang, K.K.; Jiang, H.; Kloc, C.

    2013-02-15

    SnS{sub 2} is a layered semiconductor with a van der Waals gap separating the covalently bonded layers. In this study, post-synthesis intercalation of donor organic amine molecules, such as ethylenediamine (en), into tin disulfide and secondary intercalation of p-phenylenediamine (PPD) and 1, 5-naphthalenediamine (NDA) into SnS{sub 2e}n have been verified with X-ray diffraction. PPD and NDA did not intercalate directly even during prolonged annealing but replaced en readily if en was already present in the van der Waals gap. The c-lattice dilation is proportional to the intercalant size. Unit cell lattices of intercalated products were determined from the positions of the X-ray diffraction peaks. Optical images taken during the intercalation showed that intercalation progressed from the periphery towards the interior of the crystal. TEM diffraction patterns in the [0 0 1] direction of SnS{sub 2} after intercalation revealed defects and stacking mismatches among the SnS{sub 2} layers caused by the intercalation. UV-Vis absorption studies showed a red shift in the band edge of the SnS{sub 2} material after intercalation. The band edge was 2.2 eV for pristine SnS{sub 2}; after intercalation with en or PPD, the absorbance spectra band edges shifted to approximately 0.7 eV or 0.5 eV, respectively. - Graphical Abstract: SnS{sub 2} single crystals were intercalated with organic amine molecules such as ethylenediamine, phenylenediamine and naphthalenediamine. Absorption studies showed red shift of band edge after intercalation, which was consistent with optical observations. X-ray diffraction indicated lattice dilation in the c-lattice of SnS{sub 2} after intercalation. Highlights: Black-Right-Pointing-Pointer Organic molecules intercalated inhomogenously between covalently bonded SnS{sub 2} layers. Black-Right-Pointing-Pointer Ethylenediamine (en) intercalate directly into SnS{sub 2}. Black-Right-Pointing-Pointer Phenylenediamine (PPD) and naphthalenediamine (NDA) can be

  2. Localized Scale Coupling and New Educational Paradigms in Multiscale Mathematics and Science

    SciTech Connect (OSTI)

    LEAL, L. GARY

    2013-06-30

    One of the most challenging multi-scale simulation problems in the area of multi-phase materials is to develop effective computational techniques for the prediction of coalescence and related phenomena involving rupture of a thin liquid film due to the onset of instability driven by van der Waals or other micro-scale attractive forces. Accurate modeling of this process is critical to prediction of the outcome of milling processes for immiscible polymer blends, one of the most important routes to new advanced polymeric materials. In typical situations, the blend evolves into an ?emulsion? of dispersed phase drops in a continuous matrix fluid. Coalescence is then a critical factor in determining the size distribution of the dispersed phase, but is extremely difficult to predict from first principles. The thin film separating two drops may only achieve rupture at dimensions of approximately 10 nm while the drop sizes are 0(10 ?m). It is essential to achieve very accurate solutions for the flow and for the interface shape at both the macroscale of the full drops, and within the thin film (where the destabilizing disjoining pressure due to van der Waals forces is proportional approximately to the inverse third power of the local film thickness, h-3). Furthermore, the fluids of interest are polymeric (through Newtonian) and the classical continuum description begins to fail as the film thins ? requiring incorporation of molecular effects, such as a hybrid code that incorporates a version of coarse grain molecular dynamics within the thin film coupled with a classical continuum description elsewhere in the flow domain. Finally, the presence of surface active additions, either surfactants (in the form of di-block copolymers) or surface-functionalized micro- or nano-scale particles, adds an additional level of complexity, requiring development of a distinct numerical method to predict the nonuniform concentration gradients of these additives that are responsible for

  3. Deepwater Spawning of Fall Chinook Salmon (Oncorhynchus tshawytscha) Near Ives and Pierce Island of the Columbia River, 2000.

    SciTech Connect (OSTI)

    Mueller, Robert P.

    2001-10-01

    Fall chinook salmon (Oncorhynchus tshawytscha), thought to originate from Bonneville Hatchery, were first noted to be spawning downstream of Bonneville Dam by Washington Department of Fisheries and Wildlife (WDFW) biologists in 1993 (Hymer 1997). Known spawning areas included gravel beds on the Washington side of the river near Hamilton Creek and Ives Island. The size of this population from 1994 to 1996 was estimated at 1,800 to 5,200 fish (Hymer 1997), and 554 fish in 1998 (Van der Naald et al. 1999). These estimates were based on carcass surveys and visual observation of redds by boat near the shoreline. Pacific Northwest National Laboratory (PNNL) conducted underwater video surveys in the fall of 1999 and 2000 to determine the extent of the fall chinook salmon spawning and to estimate the number of redds occurring in deeper water. Estimates of redds occurring in water depths exceeding 2.2 m at 143,000 cubic feet per second (kcfs) were 499 in 1999 (Mueller and Dauble 1999) and 567 redds >2.2 m at 127 kcfs in 2000 (this study). The majority of the redds found were confined near the main river channel adjacent to Pierce Island. Chum salmon (O. keta) also have been documented using the mouth of Hamilton Creek and portions of Hamilton Slough for spawning. The majority of chum salmon were found to spawn in shallow water at the mouth of Hamilton Creek adjacent to Ives Island. Estimates of the natural chum salmon spawning population for 1998 were 226 (Van der Naald et al. 1999). Chum salmon spawning near Ives Island are part of the Columbia River evolutionary significant unit (ESU), and are included in the Endangered Species Act of 1973 (ESA) listing in March 1999. Our main objective of this study was to locate deep water spawning locations of fall chinook salmon in the main Columbia River channel and to collect additional data on physical habitat parameters at spawning sites. The secondary objective was to map any chum salmon redds located in the deep sections of

  4. Molecular interactions with ice: Molecular embedding, adsorption, detection, and release

    SciTech Connect (OSTI)

    Gibson, K. D.; Langlois, Grant G.; Li, Wenxin; Sibener, S. J.; Killelea, Daniel R.

    2014-11-14

    The interaction of atomic and molecular species with water and ice is of fundamental importance for chemistry. In a previous series of publications, we demonstrated that translational energy activates the embedding of Xe and Kr atoms in the near surface region of ice surfaces. In this paper, we show that inert molecular species may be absorbed in a similar fashion. We also revisit Xe embedding, and further probe the nature of the absorption into the selvedge. CF{sub 4} molecules with high translational energies (?3 eV) were observed to embed in amorphous solid water. Just as with Xe, the initial adsorption rate is strongly activated by translational energy, but the CF{sub 4} embedding probability is much less than for Xe. In addition, a larger molecule, SF{sub 6}, did not embed at the same translational energies that both CF{sub 4} and Xe embedded. The embedding rate for a given energy thus goes in the order Xe > CF{sub 4} > SF{sub 6}. We do not have as much data for Kr, but it appears to have a rate that is between that of Xe and CF{sub 4}. Tentatively, this order suggests that for Xe and CF{sub 4}, which have similar van der Waals radii, the momentum is the key factor in determining whether the incident atom or molecule can penetrate deeply enough below the surface to embed. The more massive SF{sub 6} molecule also has a larger van der Waals radius, which appears to prevent it from stably embedding in the selvedge. We also determined that the maximum depth of embedding is less than the equivalent of four layers of hexagonal ice, while some of the atoms just below the ice surface can escape before ice desorption begins. These results show that energetic ballistic embedding in ice is a general phenomenon, and represents a significant new channel by which incident species can be trapped under conditions where they would otherwise not be bound stably as surface adsorbates. These findings have implications for many fields including environmental science, trace gas

  5. Indoor Air Quality and Ventilation in Residential Deep Energy...

    Office of Scientific and Technical Information (OSTI)

    The results indicate that DERs can provide adequate ventilation and IAQ, and that DERs should prioritize source control, particle filtration and well-designed local exhaust systems...

  6. Influence of nanostructure on charge transport in RuO{sub 2} thin films

    SciTech Connect (OSTI)

    Steeves, M. M.; Lad, R. J.

    2010-07-15

    Polycrystalline thin films of RuO{sub 2} were grown on fused-quartz substrates and a parametric study was carried out to probe the influence of film nanostructure on the four-point Van der Pauw resistivity and Hall coefficient. The films were grown via reactive rf magnetron sputtering of a Ru target in an Ar/O{sub 2} plasma using deposition rates from 0.27 to 3.5 A/s and substrate temperatures from 16 to 500 deg. C Room-temperature resistivities of the RuO{sub 2} films ranged from 58 to 360 {mu}{Omega} cm. Upon first heating following deposition, some films showed decreasing resistivity with increasing temperature, but the resistivities also decreased upon subsequent cooling suggesting that the annealing treatment reduces the film defect density. The temperature coefficient of resistance was found to be small (<0.001 K{sup -1}) in agreement with previous investigations. Hall coefficient measurements of the polycrystalline thin films demonstrated that either n-type or p-type majority carriers can be present depending on deposition conditions and the resulting nanostructure, in contrast to single-crystal RuO{sub 2}, which is an n-type metal. Grain size and homogeneous strain within the films were measured by x-ray diffraction and are correlated to the majority carrier type.

  7. Structural characterization and AC conductivity of bis tetrapropylammonium hexachlorado-dicadmate, [N(C{sub 3}H{sub 7}){sub 4}]{sub 2}Cd{sub 2}Cl{sub 6}

    SciTech Connect (OSTI)

    Hannachi, N.; Guidara, K.; Bulou, A.; Hlel, F.

    2010-11-15

    Synthesis, crystal structure, vibrational study, {sup 13}C, {sup 111}Cd CP-MAS-NMR analysis and electrical properties of the compound [N(C{sub 3}H{sub 7}){sub 4}]{sub 2}Cd{sub 2}Cl{sub 6}, are reported. The latter crystallizes in the triclinic system (space group P1-bar, Z = 2) with the following unit cell dimensions: a = 9.530(1) A, b = 11.744(1) A, c = 17.433(1) A, {alpha} = 79.31(1){sup o}, {beta} = 84.00(1){sup o} and {gamma} = 80.32(1){sup o}. Besides, its structure was solved using 6445 independent reflections down to R = 0.037. The atomic arrangement can be described by alternating organic and inorganic layers parallel to the (11-bar 0) plan, made up of tetrapropylammonium groups and Cd{sub 2}Cl{sub 6} dimers, respectively. In crystal structure, the inorganic layer, built up by Cd{sub 2}Cl{sub 6} dimers, is connected to the organic ones through van der Waals interaction in order to build cation-anion-cation cohesion. Impedance spectroscopy study, reported in the sample, reveals that the conduction in the material is due to a hopping process. The temperature and frequency dependence of dielectric constants of the single crystal sample has been investigated to determine some related parameters to the dielectric relaxation.

  8. Understanding the Adsorption Mechanism of Xe and Kr in a Metal-Organic Framework from X-ray Structural Analysis and First- Principles Calculations

    SciTech Connect (OSTI)

    Ghose, Sanjit K.; Li, Yan; Yakovenko, Andrey; Dooryhee, Eric; Ehm, Lars; Ecker, Lynne E.; Dippel, Ann-Christin; Halder, Gregory J.; Strachan, Denis M.; Thallapally, Praveen K.

    2015-04-16

    Enhancement of adsorption capacity and separation of radioactive Xe/Kr at room temperature and above is a challenging problem. Here, we report a detailed structural refinement and analysis of the synchrotron X-ray powder diffraction data of Ni-DODBC metal organic framework with in situ Xe and Kr adsorption at room temperature and above. Our results reveal that Xe and Kr adsorb at the open metal sites, with adsorption geometries well reproduced by DFT calculations. The measured temperature-dependent adsorption capacity of Xe is substantially larger than that for Kr, indicating the selectivity of Xe over Kr and is consistent with the more negative adsorption energy (dominated by van der Waals dispersion interactions) predicted from DFT. Our results reveal critical structural and energetic information about host–guest interactions that dictate the selective adsorption mechanism of these two inert gases, providing guidance for the design and synthesis of new MOF materials for the separation of environmentally hazardous gases from nuclear reprocessing applications.

  9. Atomic charges for modeling metal–organic frameworks: Why and how

    SciTech Connect (OSTI)

    Hamad, Said Balestra, Salvador R.G.; Bueno-Perez, Rocio; Calero, Sofia; Ruiz-Salvador, A. Rabdel

    2015-03-15

    Atomic partial charges are parameters of key importance in the simulation of Metal–Organic Frameworks (MOFs), since Coulombic interactions decrease with the distance more slowly than van der Waals interactions. But despite its relevance, there is no method to unambiguously assign charges to each atom, since atomic charges are not quantum observables. There are several methods that allow the calculation of atomic charges, most of them starting from the electronic wavefunction or the electronic density or the system, as obtained with quantum mechanics calculations. In this work, we describe the most common methods employed to calculate atomic charges in MOFs. In order to show the influence that even small variations of structure have on atomic charges, we present the results that we obtained for DMOF-1. We also discuss the effect that small variations of atomic charges have on the predicted structural properties of IRMOF-1. - Graphical abstract: We review the different method with which to calculate atomic partial charges that can be used in force field-based calculations. We also present two examples that illustrate the influence of the geometry on the calculated charges and the influence of the charges on structural properties. - Highlights: • The choice of atomic charges is crucial in modeling adsorption and diffusion in MOFs. • Methods for calculating atomic charges in MOFs are reviewed. • We discuss the influence of the framework geometry on the calculated charges. • We discuss the influence of the framework charges on structural the properties.

  10. Microstructure-Dependent Gas Adsorption: Accurate Predictions of Methane Uptake in Nanoporous Carbons

    SciTech Connect (OSTI)

    Ihm, Yungok; Cooper, Valentino R; Gallego, Nidia C; Contescu, Cristian I; Morris, James R

    2014-01-01

    We demonstrate a successful, efficient framework for predicting gas adsorption properties in real materials based on first-principles calculations, with a specific comparison of experiment and theory for methane adsorption in activated carbons. These carbon materials have different pore size distributions, leading to a variety of uptake characteristics. Utilizing these distributions, we accurately predict experimental uptakes and heats of adsorption without empirical potentials or lengthy simulations. We demonstrate that materials with smaller pores have higher heats of adsorption, leading to a higher gas density in these pores. This pore-size dependence must be accounted for, in order to predict and understand the adsorption behavior. The theoretical approach combines: (1) ab initio calculations with a van der Waals density functional to determine adsorbent-adsorbate interactions, and (2) a thermodynamic method that predicts equilibrium adsorption densities by directly incorporating the calculated potential energy surface in a slit pore model. The predicted uptake at P=20 bar and T=298 K is in excellent agreement for all five activated carbon materials used. This approach uses only the pore-size distribution as an input, with no fitting parameters or empirical adsorbent-adsorbate interactions, and thus can be easily applied to other adsorbent-adsorbate combinations.

  11. Carbon based thirty six atom spheres

    DOE Patents [OSTI]

    Piskoti, Charles R.; Zettl, Alex K.; Cohen, Marvin L.; Cote, Michel; Grossman, Jeffrey C.; Louie, Steven G.

    2005-09-06

    A solid phase or form of carbon is based on fullerenes with thirty six carbon atoms (C.sub.36). The C.sub.36 structure with D.sub.6h symmetry is one of the two most energetically favorable, and is conducive to forming a periodic system. The lowest energy crystal is a highly bonded network of hexagonal planes of C.sub.36 subunits with AB stacking. The C.sub.36 solid is not a purely van der Waals solid, but has covalent-like bonding, leading to a solid with enhanced structural rigidity. The solid C.sub.36 material is made by synthesizing and selecting out C.sub.36 fullerenes in relatively large quantities. A C.sub.36 rich fullerene soot is produced in a helium environment arc discharge chamber by operating at an optimum helium pressure (400 torr). The C.sub.36 is separated from the soot by a two step process. The soot is first treated with a first solvent, e.g. toluene, to remove the higher order fullerenes but leave the C.sub.36. The soot is then treated with a second solvent, e.g. pyridine, which is more polarizable than the first solvent used for the larger fullerenes. The second solvent extracts the C.sub.36 from the soot. Thin films and powders can then be produced from the extracted C.sub.36. Other materials are based on C.sub.36 fullerenes, providing for different properties.

  12. Density functional theory calculations of the turbostratically disordered compound [(SnSe)1+y]m(VSe2)n

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

    Rudin, Sven P.; Johnson, David C.

    2015-04-30

    Among composite materials that layer constituent substances of nanoscale thicknesses, [(SnSe)1+y ]m(VSe2)n emerges as an example where the constituents retain incommensurate lattice structures. Perpendicular to the stacking direction, the system exhibits random translations and random rotations on average, i.e., turbostratic disorder, with local regions showing twelvefold diffraction patterns. Earlier theoretical work on these structures showed that combining density functional theory with an empirical treatment of the van der Waals interaction gave structural parameters in good agreement with experiment, but no attempt was made to examine the relative orientations. Here we approximate the extended system with one extended constituent and onemore » finite constituent, which allows the treatment of all relative orientations on equal footing. Furthermore, the calculations show how the twelvefold periodicity follows from how the ions of the SnSe layer lock in with favored positions relative to the VSe2 layer, and the associated energy scale supports arguments for the overall turbostratic disorder.« less

  13. Assessing electronic structure approaches for gas-ligand interactions in metal-organic frameworks: The CO{sub 2}-benzene complex

    SciTech Connect (OSTI)

    Witte, Jonathon; Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 ; Neaton, Jeffrey B.; Head-Gordon, Martin; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720

    2014-03-14

    Adsorption of gas molecules in metal-organic frameworks is governed by many factors, the most dominant of which are the interaction of the gas with open metal sites, and the interaction of the gas with the ligands. Herein, we examine the latter class of interaction in the context of CO{sub 2} binding to benzene. We begin by clarifying the geometry of the CO{sub 2}benzene complex. We then generate a benchmark binding curve using a coupled-cluster approach with single, double, and perturbative triple excitations [CCSD(T)] at the complete basis set (CBS) limit. Against this ?CCSD(T)/CBS standard, we evaluate a plethora of electronic structure approximations: Hartree-Fock, second-order Mller-Plesset perturbation theory (MP2) with the resolution-of-the-identity approximation, attenuated MP2, and a number of density functionals with and without different empirical and nonempirical van der Waals corrections. We find that finite-basis MP2 significantly overbinds the complex. On the other hand, even the simplest empirical correction to standard density functionals is sufficient to bring the binding energies to well within 1 kJ/mol of the benchmark, corresponding to an error of less than 10%; PBE-D in particular performs well. Methods that explicitly include nonlocal correlation kernels, such as VV10, vdW-DF2, and ?B97X-V, perform with similar accuracy for this system, as do ?B97X and M06-L.

  14. An Assessment of Density Functional Methods for Potential Energy Curves of Nonbonded Interactions: The XYG3 and B97-D Approximations

    SciTech Connect (OSTI)

    Vazquez-Mayagoitia, Alvaro; Sherrill, David; Apra, Edoardo; Sumpter, Bobby G

    2010-01-01

    A recently proposed double-hybrid functional called XYG3 and a semilocal GGA functional (B97-D) with a semiempirical correction for van der Waals interactions have been applied to study the potential energy curves along the dissociation coordinates of weakly bound pairs of molecules governed by London dispersion and induced dipole forces. Molecules treated in this work were the parallel sandwich, T-shaped, and parallel-displaced benzene dimer, (C6H6)2; hydrogen sulfide and benzene, H2S C6H6; methane and benzene, CH4 C6H6; the methane dimer, (CH4)2; and the pyridine dimer, (C5H5N)2. We compared the potential energy curves of these functionals with previously published benchmarks at the coupled cluster singles, doubles, and perturbative triplets [CCSD(T)] complete-basis-set limit. Both functionals, XYG3 and B97-D, exhibited very good performance, reproducing accurate energies for equilibrium distances and a smooth behavior along the dissociation coordinate. Overall, we found an agreement within a few tenths of one kcal mol-1 with the CCSD(T) results across the potential energy curves.

  15. Generation of defects in model lubricant monolayers and their contribution to energy dissipation in friction

    SciTech Connect (OSTI)

    Salmeron, Miquel

    2000-06-15

    The structural, mechanical (friction) and spectroscopic properties of model lubricant films made of self-assembled and Langmuir-Blodgett monolayers on quartz, mica and gold have been investigated with atomic force microscopy, surface forces apparatus and sum frequency generation. In these films, the molecules tend to form densely packed structures, with the alkane chains mostly vertical and parallel to each other. The SFG results suggest that under moderate pressures of a few tens of MPa, the methyl end group of the alkane chains is rotated to accommodate a terminal gauche distortion. The molecule,however, retains its upright close packed structure with a lattice periodicity when ordered, which can be resolved by AFM. At pressures above 0.1 GPa, changes in the form of collective molecular tilts take place that lower the height of the monolayer. Only certain angles of tilt are allowed that are explained by the interlocking of methylene units in neighboring chains. The discrete angular tilts are accompanied by increases in friction. A model based on the van derWaals attractive energy between chains is used to explain the stability of the films and to estimate the cohesive energy changes during tilt and, from that, the increases in friction force.

  16. Probing the Role of Interlayer Coupling and Coulomb Interactions on Electronic Structure in Few-Layer MoSe 2 Nanostructures

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

    Bradley, Aaron J.; M. Ugeda, Miguel; da Jornada, Felipe H.; Qiu, Diana Y.; Ruan, Wei; Zhang, Yi; Wickenburg, Sebastian; Riss, Alexander; Lu, Jiong; Mo, Sung-Kwan; et al

    2015-03-16

    Despite the weak nature of interlayer forces in transition metal dichalcogenide (TMD) materials, their properties are highly dependent on the number of layers in the few-layer two-dimensional (2D) limit. Here, we present a combined scanning tunneling microscopy/spectroscopy and GW theoretical study of the electronic structure of high quality single- and few-layer MoSe2 grown on bilayer graphene. We find that the electronic (quasiparticle) bandgap, a fundamental parameter for transport and optical phenomena, decreases by nearly one electronvolt when going from one layer to three due to interlayer coupling and screening effects. Our results paint a clear picture of the evolution ofmore » the electronic wave function hybridization in the valleys of both the valence and conduction bands as the number of layers is changed. This demonstrates the importance of layer number and electron-electron interactions on van der Waals heterostructures and helps to clarify how their electronic properties might be tuned in future 2D nanodevices.« less

  17. Analytical energy gradient for the two-component normalized elimination of the small component method

    SciTech Connect (OSTI)

    Zou, Wenli; Filatov, Michael; Cremer, Dieter

    2015-06-07

    The analytical gradient for the two-component Normalized Elimination of the Small Component (2c-NESC) method is presented. The 2c-NESC is a Dirac-exact method that employs the exact two-component one-electron Hamiltonian and thus leads to exact Dirac spin-orbit (SO) splittings for one-electron atoms. For many-electron atoms and molecules, the effect of the two-electron SO interaction is modeled by a screened nucleus potential using effective nuclear charges as proposed by Boettger [Phys. Rev. B 62, 7809 (2000)]. The effect of spin-orbit coupling (SOC) on molecular geometries is analyzed utilizing the properties of the frontier orbitals and calculated SO couplings. It is shown that bond lengths can either be lengthened or shortened under the impact of SOC where in the first case the influence of low lying excited states with occupied antibonding orbitals plays a role and in the second case the jj-coupling between occupied antibonding and unoccupied bonding orbitals dominates. In general, the effect of SOC on bond lengths is relatively small (≤5% of the scalar relativistic changes in the bond length). However, large effects are found for van der Waals complexes Hg{sub 2} and Cn{sub 2}, which are due to the admixture of more bonding character to the highest occupied spinors.

  18. Electronic Structures, Bonding Configurations, and Band-Gap-Opening Properties of Graphene Binding with Low-Concentration Fluorine

    SciTech Connect (OSTI)

    Duan, Yuhua; Stinespring, Charter D.; Chorpening, Benjamin

    2015-06-18

    To better understand the effects of low-level fluorine in graphene-based sensors, first-principles density functional theory (DFT) with van der Waals dispersion interactions has been employed to investigate the structure and impact of fluorine defects on the electrical properties of single-layer graphene films. The results show that both graphite-2H and graphene have zero band gaps. When fluorine bonds to a carbon atom, the carbon atom is pulled slightly above the graphene plane, creating what is referred to as a CF defect. The lowest-binding energy state is found to correspond to two CF defects on nearest neighbor sites, with one fluorine above the carbon plane and the other below the plane. Overall this has the effect of buckling the graphene. The results further show that the addition of fluorine to graphene leads to the formation of an energy band (BF) near the Fermi level, contributed mainly from the 2p orbitals of fluorine with a small contribution from the porbitals of the carbon. Among the 11 binding configurations studied, our results show that only in two cases does the BF serve as a conduction band and open a band gap of 0.37 eV and 0.24 eV respectively. The binding energy decreases with decreasing fluorine concentration due to the interaction between neighboring fluorine atoms. The obtained results are useful for sensor development and nanoelectronics.

  19. Wrinkles of graphene on Ir(111): Macroscopic network ordering and internal multi-lobed structure

    SciTech Connect (OSTI)

    Petrovic, Marin; Sadowski, Jerzy T.; Siber, Antonio; Kralj, Marko

    2015-07-17

    The large-scale production of graphene monolayer greatly relies on epitaxial samples which often display stress-relaxation features in the form of wrinkles. Wrinkles of graphene on Ir(111) are found to exhibit a fairly well ordered interconnecting network which is characterized by low-energy electron microscopy (LEEM). The high degree of quasi-hexagonal network arrangement for the graphene aligned to the underlying substrate can be well described as a (non-Poissonian) Voronoi partition of a plane. The results obtained strongly suggest that the wrinkle network is frustrated at low temperatures, retaining the order inherited from elevated temperatures when the wrinkles interconnect in junctions which most often join three wrinkles. Such frustration favors the formation of multi-lobed wrinkles which are found in scanning tunneling microscopy (STM) measurements. The existence of multiple lobes is explained within a model accounting for the interplay of the van der Waals attraction between graphene and iridium and bending energy of the wrinkle. The presented study provides new insights into wrinkling of epitaxial graphene and can be exploited to further expedite its application.

  20. Nonaqueous electrolyte for electrical storage devices

    DOE Patents [OSTI]

    McEwen, Alan B. (Melrose, MA); Yair, Ein-Eli (Waltham, MA)

    1999-01-01

    Improved nonaqueous electrolytes for application in electrical storage devices such as electrochemical capacitors or batteries are disclosed. The electrolytes of the invention contain salts consisting of alkyl substituted, cyclic delocalized aromatic cations, and their perfluoro derivatives, and certain polyatomic anions having a van der Waals volume less than or equal to 100 .ANG..sup.3, preferably inorganic perfluoride anions and most preferably PF.sub.6.sup.-, the salts being dissolved in organic liquids, and preferably alkyl carbonate solvents, or liquid sulfur dioxide or combinations thereof, at a concentration of greater than 0.5M and preferably greater than 1.0M. Exemplary electrolytes comprise 1-ethyl-3-methylimidazolium hexafluorophosphate dissolved in a cyclic or acylic alkyl carbonate, or methyl formate, or a combination therof. These improved electrolytes have useful characteristics such as higher conductivity, higher concentration, higher energy storage capabilities, and higher power characteristics compared to prior art electrolytes. Stacked capacitor cells using electrolytes of the invention permit high energy, high voltage storage.

  1. Imaging Hindered Rotations of Alkoxy Species on TiO2(110)

    SciTech Connect (OSTI)

    Zhang, Zhenrong; Rousseau, Roger J.; Gong, Jinlong; Kay, Bruce D.; Dohnalek, Zdenek

    2009-12-16

    We present the first study of the rotational dynamics of organic species on any oxide surface. Specifically, variable-temperature scanning tunneling microscopy (STM) and dispersion-corrected density functional theory are used to study the alkyl chain conformational disorder and dynamics of 1-, 2-, 3- and 4-octoxy on rutile TiO2(110). Initially, the geminate pairs of the octoxy and bridging hydroxyl species are created via octanol dissociation on bridging-oxygen (Ob) vacancy defects. The STM images provide time averaged snapshots of octoxy species rotating among multiple energetically nearly-degenerate configurations accessible at a given temperature. In the calculations we find that the underlying corrugated potential energy surface is a result of the interplay between attractive Van der Waals dispersion forces leading to weak attractive C...Ti and repulsive C...Ob interactions which lead to large barriers of 50-70kJmol-1 for the rotation of the octoxy alkyl chains across the Ob rows. In the presence of the germinal hydroxyl groups we find that the relative populations of the various conformations as well as the rotational barriers are perturbed by the presence of geminate hydroxyl due to additional C...hydroxyl repulsions.

  2. Low-frequency 1/f noise in MoS{sub 2} transistors: Relative contributions of the channel and contacts

    SciTech Connect (OSTI)

    Renteria, J.; Jiang, C.; Samnakay, R.; Rumyantsev, S. L.; Goli, P.; Balandin, A. A.; Shur, M. S.

    2014-04-14

    We report on the results of the low-frequency (1/f, where f is frequency) noise measurements in MoS{sub 2} field-effect transistors revealing the relative contributions of the MoS{sub 2} channel and Ti/Au contacts to the overall noise level. The investigation of the 1/f noise was performed for both as fabricated and aged transistors. It was established that the McWhorter model of the carrier number fluctuations describes well the 1/f noise in MoS{sub 2} transistors, in contrast to what is observed in graphene devices. The trap densities extracted from the 1/f noise data for MoS{sub 2} transistors, are 2??10{sup 19}?eV{sup ?1}cm{sup ?3} and 2.5??10{sup 20}?eV{sup ?1}cm{sup ?3} for the as fabricated and aged devices, respectively. It was found that the increase in the noise level of the aged MoS{sub 2} transistors is due to the channel rather than the contact degradation. The obtained results are important for the proposed electronic applications of MoS{sub 2} and other van der Waals materials.

  3. Solvation Phenomena in Dilute Solutions: Formal, Experimental Evidence, and Modeling Implications

    SciTech Connect (OSTI)

    Chialvo, Ariel A

    2013-01-01

    We review the fundamentals underlying a general molecular-based formalism for the microscopic interpretation of the solvation phenomena involving sparingly soluble solutes in compressible media, an approach that hinges around the unambiguous splitting of the species correlation function integrals into short-(finite) and long-ranged (diverging) contributions at infinite dilution, where this condition is taken as the reference system for the derivation of composition expansions. Then, we invoke the formalism (a) to illustrate the well-behaved nature of the solvation contributions to the mechanical partial molecular properties of solutes at infinite dilution, (b) to guide the development of, and provide molecular-based support to, the macroscopic modeling of high-temperature dilute aqueous-electrolyte solutions, (c) to study solvation effects on the kinetic rate constants of reactions in near-critical solvents in an attempt to understand from a microscopic perspective the macroscopic evidence regarding the thermodynamic pressure effects, and (d) to interpret the microscopic mechanism behind synergistic solvation effects involving either co-solutes or co-solvents, and provide a molecular argument on the unsuitability of the van der Waals one-fluid (vdW-1f) mixing rules for the 2 description of weakly attractive solutes in compressible solvents. Finally, we develop thermodynamically consistent perturbation expansions, around the infinite dilution reference, for the species residual properties in binary and ternary mixtures, and discuss the theoretical and modeling implications behind ad hoc first-order truncated expansions.

  4. Hydrophobic ionic liquids

    DOE Patents [OSTI]

    Koch, Victor R.; Nanjundiah, Chenniah; Carlin, Richard T.

    1998-01-01

    Ionic liquids having improved properties for application in non-aqueous batteries, electrochemical capacitors, electroplating, catalysis and chemical separations are disclosed. Exemplary compounds have one of the following formulas: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are either H; F; separate alkyl groups of from 1 to 4 carbon atoms, respectively, or joined together to constitute a unitary alkylene radical of from 2 to 4 carbon atoms forming a ring structure converging on N; or separate phenyl groups; and wherein the alkyl groups, alkylene radicals or phenyl groups may be substituted with electron withdrawing groups, preferably F--, Cl--, CF.sub.3 --, SF.sub.5 --, CF.sub.3 S--, (CF.sub.3).sub.2 CHS-- or (CF.sub.3).sub.3 CS--; and X.sup.- is a non-Lewis acid-containing polyatomic anion having a van der Waals volume exceeding 100 .ANG..sup.3.

  5. Hydrophobic ionic liquids

    DOE Patents [OSTI]

    Koch, V.R.; Nanjundiah, C.; Carlin, R.T.

    1998-10-27

    Ionic liquids having improved properties for application in non-aqueous batteries, electrochemical capacitors, electroplating, catalysis and chemical separations are disclosed. Exemplary compounds have one of the following formulas shown in a diagram wherein R{sub 1}, R{sub 2}, R{sub 3}, R{sub 4}, R{sub 5}, and R{sub 6} are either H; F; separate alkyl groups of from 1 to 4 carbon atoms, respectively, or joined together to constitute a unitary alkylene radical of from 2 to 4 carbon atoms forming a ring structure converging on N; or separate phenyl groups; and wherein the alkyl groups, alkylene radicals or phenyl groups may be substituted with electron withdrawing groups, preferably F-, Cl-, CF{sub 3}-, SF{sub 5}-, CF{sub 3}S-, (CF{sub 3}){sub 2}CHS- or (CF{sub 3}){sub 3}CS-; and X{sup {minus}} is a non-Lewis acid-containing polyatomic anion having a van der Waals volume exceeding 100 {angstrom}{sup 3}. 4 figs.

  6. Structural Basis for Streptogramin B Resistance in Staphylococcus aureus by Virginiamycin B Lyase

    SciTech Connect (OSTI)

    Korczynska,M.; Mukhtar, T.; Wright, G.; Berghuis, A.

    2007-01-01

    The streptogramin combination therapy of quinupristin-dalfopristin (Synercid) is used to treat infections caused by bacterial pathogens, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. However, the effectiveness of this therapy is being compromised because of an increased incidence of streptogramin resistance. One of the clinically observed mechanisms of resistance is enzymatic inactivation of the type B streptogramins, such as quinupristin, by a streptogramin B lyase, i.e., virginiamycin B lyase (Vgb). The enzyme catalyzes the linearization of the cyclic antibiotic via a cleavage that requires a divalent metal ion. Here, we present crystal structures of Vgb from S. aureus in its apoenzyme form and in complex with quinupristin and Mg{sup 2+} at 1.65- and 2.8-{angstrom} resolution, respectively. The fold of the enzyme is that of a seven-bladed {beta}-propeller, although the sequence reveals no similarity to other known members of this structural family. Quinupristin binds to a large depression on the surface of the enzyme, where it predominantly forms van der Waals interactions. Validated by site-directed mutagenesis studies, a reaction mechanism is proposed in which the initial abstraction of a proton is facilitated by a Mg{sup 2+}-linked conjugated system. Analysis of the Vgb-quinupristin structure and comparison with the complex between quinupristin and its natural target, the 50S ribosomal subunit, reveals features that can be exploited for developing streptogramins that are impervious to Vgb-mediated resistance.

  7. New approach for the solution of optimal control problems on parallel machines. Doctoral thesis

    SciTech Connect (OSTI)

    Stech, D.J.

    1990-01-01

    This thesis develops a highly parallel solution method for nonlinear optimal control problems. Balakrishnan's epsilon method is used in conjunction with the Rayleigh-Ritz method to convert the dynamic optimization of the optimal control problem into a static optimization problem. Walsh functions and orthogonal polynomials are used as basis functions to implement the Rayleigh-Ritz method. The resulting static optimization problem is solved using matrix operations which have well defined massively parallel solution methods. To demonstrate the method, a variety of nonlinear optimal control problems are solved. The nonlinear Raleigh problem with quadratic cost and nonlinear van der Pol problem with quadratic cost and terminal constraints on the states are solved in both serial and parallel on an eight processor Intel Hypercube. The solutions using both Walsh functions and Legendre polynomials as basis functions are given. In addition to these problems which are solved in parallel, a more complex nonlinear minimum time optimal control problem and nonlinear optimal control problem with an inequality constraint on the control are solved. Results show the method converges quickly, even from relatively poor initial guesses for the nominal trajectories.

  8. An NMR (Nuclear Magnetic Resonance) Investigation of the Chemical Association and Molecular Dynamics in Asphalt Ridge Tar Sand Ore and Bitumen

    DOE R&D Accomplishments [OSTI]

    Netzel, D. A.; Coover, P. T.

    1987-09-01

    Preliminary studies on tar sand bitumen given in this report have shown that the reassociation of tar sand bitumen to its original molecular configuration after thermal stressing is a first-order process requiring nearly a week to establish equilibrium. Studies were also conducted on the dissolution of tar sand bitumen in solvents of varying polarity. At a high-weight fraction of solute to solvent the apparent molecular weight of the bitumen molecules was greater than that of the original bitumen when dissolved in chloroform-d{sub 1} and benzene-d{sub 6}. This increase in the apparent molecular weight may be due to micellar formation or a weak solute-solvent molecular complex. Upon further dilution with any of the solvents studied, the apparent molecular weight of the tar sand bitumen decreased because of reduced van der Waals forces of interaction and/or hydrogen bonding. To define the exact nature of the interactions, it will be necessary to have viscosity measurements of the solutions.

  9. Structural, magnetic, and transport properties of Permalloy for spintronic experiments

    SciTech Connect (OSTI)

    Nahrwold, Gesche; Scholtyssek, Jan M.; Motl-Ziegler, Sandra; Albrecht, Ole; Merkt, Ulrich; Meier, Guido

    2010-07-15

    Permalloy (Ni{sub 80}Fe{sub 20}) is broadly used to prepare magnetic nanostructures for high-frequency experiments where the magnetization is either excited by electrical currents or magnetic fields. Detailed knowledge of the material properties is mandatory for thorough understanding its magnetization dynamics. In this work, thin Permalloy films are grown by dc-magnetron sputtering on heated substrates and by thermal evaporation with subsequent annealing. The specific resistance is determined by van der Pauw methods. Point-contact Andreev reflection is employed to determine the spin polarization of the films. The topography is imaged by atomic-force microscopy, and the magnetic microstructure by magnetic-force microscopy. Transmission-electron microscopy and transmission-electron diffraction are performed to determine atomic composition, crystal structure, and morphology. From ferromagnetic resonance absorption spectra the saturation magnetization, the anisotropy, and the Gilbert damping parameter are determined. Coercive fields and anisotropy are measured by magneto-optical Kerr magnetometry. The sum of the findings enables optimization of Permalloy for spintronic experiments.

  10. Atomistic Insight on the Charging Energetics in Sub-nanometer Pore Supercacitors

    SciTech Connect (OSTI)

    Qiao, Rui; Huang, Jingsong; Sumpter, Bobby G; Meunier, Vincent; Feng, Guang

    2010-01-01

    Electrodes featuring sub-nanometer pores can significantly enhance the capacitance and energy density of supercapacitors. However, ions must pay an energy penalty to enter sub-nanometer pores as they have to shed part of their solvation shell. The magnitude of such energy penalty plays a key role in determining the accessibility and charging/discharging of these sub-nanometer pores. Here we report on the atomistic simulation of Na+ and Cl ions entering a polarizable slit pore with a width of 0.82 nm. We show that the free energy penalty for these ions to enter the pore is less than 14 kJ/mol for both Na+ and Cl ions. The surprisingly small energy penalty is caused by the van der Waals attractions between ion and pore walls, the image charge effects, the moderate (19-26%) de-hydration of the ions inside the pore, and the strengthened interactions between ions and their hydration water molecules in the sub-nanometer pore. The results provide strong impetus for further developing nanoporous electrodes featuring sub- nanometer pores.

  11. Observation of long-lived interlayer excitons in monolayer MoSe2–WSe2 heterostructures

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

    Rivera, Pasqual; Schaibley, John R.; Jones, Aaron M.; Ross, Jason S.; Wu, Sanfeng; Aivazian, Grant; Klement, Philip; Seyler, Kyle; Clark, Genevieve; Ghimire, Nirmal J.; et al

    2015-02-24

    Van der Waals bound heterostructures constructed with two-dimensional materials, such as graphene, boron nitride and transition metal dichalcogenides, have sparked wide interest in both device physics and technologies at the two-dimensional limit. One highly coveted heterostructure is that of differing monolayer transition metal dichalcogenides with type-II band alignment, with bound electrons and holes localized in individual monolayers, that is, interlayer excitons. Here, we report the observation of interlayer excitons in monolayer MoSe2–WSe2 heterostructures by photoluminescence and photoluminescence excitation spectroscopy. The energy and luminescence intensity are highly tunable by an applied vertical gate voltage. Moreover, we measure an interlayer exciton lifetimemore » of ~1.8 ns, an order of magnitude longer than intralayer excitons in monolayers. Ultimately, our work demonstrates optical pumping of interlayer electric polarization, which may provoke further exploration of interlayer exciton condensation, as well as new applications in two-dimensional lasers, light-emitting diodes and photovoltaic devices.« less

  12. Electronic Structures, Bonding Configurations, and Band-Gap-Opening Properties of Graphene Binding with Low-Concentration Fluorine

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

    Duan, Yuhua; Stinespring, Charter D.; Chorpening, Benjamin

    2015-06-18

    To better understand the effects of low-level fluorine in graphene-based sensors, first-principles density functional theory (DFT) with van der Waals dispersion interactions has been employed to investigate the structure and impact of fluorine defects on the electrical properties of single-layer graphene films. The results show that both graphite-2H and graphene have zero band gaps. When fluorine bonds to a carbon atom, the carbon atom is pulled slightly above the graphene plane, creating what is referred to as a CF defect. The lowest-binding energy state is found to correspond to two CF defects on nearest neighbor sites, with one fluorine abovemore » the carbon plane and the other below the plane. Overall this has the effect of buckling the graphene. The results further show that the addition of fluorine to graphene leads to the formation of an energy band (BF) near the Fermi level, contributed mainly from the 2p orbitals of fluorine with a small contribution from the porbitals of the carbon. Among the 11 binding configurations studied, our results show that only in two cases does the BF serve as a conduction band and open a band gap of 0.37 eV and 0.24 eV respectively. The binding energy decreases with decreasing fluorine concentration due to the interaction between neighboring fluorine atoms. The obtained results are useful for sensor development and nanoelectronics.« less

  13. Wrinkles of graphene on Ir(111): Macroscopic network ordering and internal multi-lobed structure

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

    Petrovic, Marin; Sadowski, Jerzy T.; Siber, Antonio; Kralj, Marko

    2015-07-17

    The large-scale production of graphene monolayer greatly relies on epitaxial samples which often display stress-relaxation features in the form of wrinkles. Wrinkles of graphene on Ir(111) are found to exhibit a fairly well ordered interconnecting network which is characterized by low-energy electron microscopy (LEEM). The high degree of quasi-hexagonal network arrangement for the graphene aligned to the underlying substrate can be well described as a (non-Poissonian) Voronoi partition of a plane. The results obtained strongly suggest that the wrinkle network is frustrated at low temperatures, retaining the order inherited from elevated temperatures when the wrinkles interconnect in junctions which mostmore » often join three wrinkles. Such frustration favors the formation of multi-lobed wrinkles which are found in scanning tunneling microscopy (STM) measurements. The existence of multiple lobes is explained within a model accounting for the interplay of the van der Waals attraction between graphene and iridium and bending energy of the wrinkle. The presented study provides new insights into wrinkling of epitaxial graphene and can be exploited to further expedite its application.« less

  14. Chapter 20: Graphite

    SciTech Connect (OSTI)

    Burchell, Timothy D

    2012-01-01

    Graphite is truly a unique material. Its structure, from the nano- to the millimeter scale give it remarkable properties that lead to numerous and diverse applications. Graphite bond anisotropy, with strong in-plane covalent bonds and weak van der Waals type bonding between the planes, gives graphite its unique combination of properties. Easy shear of the crystal, facilitated by weak interplaner bonds allows graphite to be used as a dry lubricant, and is responsible for the substances name! The word graphite is derived from the Greek to write because of graphites ability to mark writing surfaces. Moreover, synthetic graphite contains within its structure, porosity spanning many orders of magnitude in size. The thermal closure of these pores profoundly affects the properties for example, graphite strength increases with temperature to temperatures in excess of 2200 C. Consequently, graphite is utilized in many high temperature applications. The basic physical properties of graphite are reviewed here. Graphite applications include metallurgical; (aluminum and steel production), single crystal silicon production, and metal casting; electrical (motor brushes and commutators); mechanical (seals, bearings and bushings); and nuclear applications, (see Chapter 91, Nuclear Graphite). Here we discuss the structure, manufacture, properties, and applications of Graphite.

  15. Atomistic simulations of nanowelding of single-crystal and amorphous gold nanowires

    SciTech Connect (OSTI)

    Wu, Cheng-Da; Fang, Te-Hua Wu, Chung-Chin

    2015-01-07

    The mechanism and quality of the welding of single-crystal (SC) and amorphous gold nanowires (NWs) with head-to-head contact are studied using molecular dynamics simulations based on the second-moment approximation of the many-body tight-binding potential. The results are discussed in terms of atomic trajectories, slip vectors, stress, and radial distribution function. Simulation results show that the alignment for the amorphous NWs during welding is easier than that for the SC NWs due to the former's relatively stable geometry. A few dislocations nucleate and propagate on the (111) close-packed plane (slip plane) inside the SC NWs during the welding and stretching processes. During welding, an incomplete jointing area first forms through the interactions of the van der Waals attractive force, and the jointing area increases with increasing extent of contact between the two NWs. A crystallization transition region forms in the jointing area for the welding of SC-amorphous or amorphous-SC NWs. With increasing interference, an amorphous gold NW shortens more than does a SC gold NW due to the former's relatively poor strength. The pressure required for welding decreases with increasing temperature.

  16. Fullerene (C60) films for solid lubrication

    SciTech Connect (OSTI)

    Bhushan, B.; Gupta, B.K.; Van Cleef, G.W.; Capp, C.E.; Coe, J.V. )

    1993-10-01

    The advent of techniques for producing gram quantities of a new form of stable, pure, solid carbon, designated as fullerene, opens a profusion of possibilities to be explored in many disciplines including tribology. Fullerenes take the form of hollow geodesic domes, which are formed from a network of pentagons and hexagons with covalently bonded carbon atoms. The C60 molecule has the highest possible symmetry (icosahedral) and assumes the shape of a soccer ball. At room temperature, fullerene molecules pack in an fcc lattice bonded with weak van der Waals attractions. Fullerenes can be dissolved in solvents such as toluene and benzene and are easily sublimed. The low surface energy, high chemical stability, spherical shape, weak intermolecular bonding, and high load bearing capacity of C60 molecules offer potential for various mechanical and tribological applications. This paper describes the crystal structure and properties of fullerenes and proposes a mechanism for self-lubricating action. Sublimed films of C60 have been produced and friction and wear performance of these films in various operating environments are the subject of this paper. The results of this study indicate that C60, owing to its unique crystal structure and bonding, may be a promising solid lubricant. 31 refs.

  17. Interactions of multiquark states in the chromodielectric model

    SciTech Connect (OSTI)

    Martens, Gunnar; Greiner, Carsten; Leupold, Stefan; Mosel, Ulrich

    2006-05-01

    We investigate 4-quark (qqqq) systems as well as multiquark states with a large number of quarks and antiquarks using the chromodielectric model. In the former type of systems the flux distribution and the corresponding energy of such systems for planar and nonplanar geometries are studied. From the comparison to the case of two independent qq-strings we deduce the interaction potential between two strings. We find an attraction between strings and a characteristic string flip if there are two degenerate string combinations between the four particles. The interaction shows no strong Van-der-Waals forces and the long range behavior of the potential is well described by a Yukawa potential, which might be confirmed in future lattice calculations. The multiquark states develop an inhomogeneous porous structure even for particle densities large compared to nuclear matter constituent quark densities. We present first results of the dependence of the system on the particle density pointing towards a percolation type of transition from a hadronic matter phase to a quark matter phase. The critical energy density is found at {epsilon}{sub c}=1.2 GeV/fm{sup 3}.

  18. A new coordination mode of (E)-3-(3-hydroxyl-phenyl)-acrylic acid in copper complex: Crystal structure and magnetic properties

    SciTech Connect (OSTI)

    Jin, Xin; Zhou, Pei; Zheng, Chunying; Li, Hui

    2015-05-15

    A copper complex ([Cu(py){sub 2}(L){sub 2}]·2CH{sub 3}OH){sub n} (HL=(E)-3-(3-hydroxyl-phenyl)-acrylic acid) (1) with acrylic acid ligand was synthesized and structurally analyzed by IR, elemental analysis, TGA and the single-crystal X-ray diffraction methods. It is the first time to find that phenolic hydroxyl of L coordinates to Cu(II). Complex 1 exhibits 1D chain by a double-bridge of ligands, and the 3D supramolecular framework in complex 1 is constructed by π–π stacking interactions and van der Waals Contacts among the 1D chains. The magnetic properties of complex 1 have been studied. - Graphical abstract: A copper complex based on (E)-3-(3-hydroxyl-phenyl)-acrylic acid in a novel coordinated way was synthesized and a ferromagnetic exchange interactions between neighboring Cu(II) ions has be achieved. - Highlights: • A new copper complex with acrylic acid ligand was synthesized and analyzed. • We find the phenolic hydroxyl of MCA ligand coordinates to metal ion firstly. • A ferromagnetic exchange interactions between Cu(II) ions has been achieved.

  19. Revealing the preferred interlayer orientations and stackings of two-dimensional bilayer gallium selenide crystals

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

    Li, Xufan; Basile Carrasco, Leonardo A.; Yoon, Mina; Ma, Cheng; Puretzky, Alexander A.; Lee, Jaekwang; Idrobo Tapia, Juan Carlos; Chi, Miaofang; Rouleau, Christopher M.; Geohegan, David B.; et al

    2015-01-21

    Characterizing and controlling the interlayer orientations and stacking order of bilayer two-dimensional (2D) crystals and van der Waals (vdW) heterostructure is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) that result from different layer stacking provide an ideal platform to study the stacking configurations in bilayer 2D crystals. Here, through a controllable vapor-phase deposition method we selectively grow bilayer GaSe crystals and investigate their two preferred 0° or 60° interlayer rotations. The commensurate stacking configurations (AA' and AB-stacking) in as-grown 2D bilayer GaSe crystals are clearly observed at the atomic scale andmore » the Ga-terminated edge structure are identified for the first time by using atomic-resolution scanning transmission electron microscopy (STEM). Theoretical analysis of the interlayer coupling energetics vs. interlayer rotation angle reveals that the experimentally-observed orientations are energetically preferred among the bilayer GaSe crystal polytypes. Here, the combined experimental and theoretical characterization of the GaSe bilayers afforded by these growth studies provide a pathway to reveal the atomistic relationships in interlayer orientations responsible for the electronic and optical properties of bilayer 2D crystals and vdW heterostructures.« less

  20. Revealing the preferred interlayer orientations and stackings of two-dimensional bilayer gallium selenide crystals

    SciTech Connect (OSTI)

    Li, Xufan; Basile Carrasco, Leonardo A.; Yoon, Mina; Ma, Cheng; Puretzky, Alexander A.; Lee, Jaekwang; Idrobo Tapia, Juan Carlos; Chi, Miaofang; Rouleau, Christopher M.; Geohegan, David B.; Xiao, Kai

    2015-01-21

    Characterizing and controlling the interlayer orientations and stacking order of bilayer two-dimensional (2D) crystals and van der Waals (vdW) heterostructure is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) that result from different layer stacking provide an ideal platform to study the stacking configurations in bilayer 2D crystals. Here, through a controllable vapor-phase deposition method we selectively grow bilayer GaSe crystals and investigate their two preferred 0° or 60° interlayer rotations. The commensurate stacking configurations (AA' and AB-stacking) in as-grown 2D bilayer GaSe crystals are clearly observed at the atomic scale and the Ga-terminated edge structure are identified for the first time by using atomic-resolution scanning transmission electron microscopy (STEM). Theoretical analysis of the interlayer coupling energetics vs. interlayer rotation angle reveals that the experimentally-observed orientations are energetically preferred among the bilayer GaSe crystal polytypes. Here, the combined experimental and theoretical characterization of the GaSe bilayers afforded by these growth studies provide a pathway to reveal the atomistic relationships in interlayer orientations responsible for the electronic and optical properties of bilayer 2D crystals and vdW heterostructures.

  1. Noniterative Inclusion of the Triply and Quadruply Excited Clusters: The Locally Renormalized Perspective

    SciTech Connect (OSTI)

    Kowalski, Karol; De Jong, Wibe A.

    2006-08-31

    Noniterative inclusion of the higher=order clusters has been a subject of intensive studies aimed at developing a well balanced description of individual many-body contributions for entire ground-state potential energy surfaces. In traditional approaches, the connected quadruples are estimated directly based on perturbative arguments, which leads to excellent agreement with full CI results near the equilibrium geometry and increasingly worse energies for larger internuclear stretches. As a possible improvement to this situation, two techniques are considered as especially promising: perturbative approaches based on the similarity transformed Hamiltonians and renormalization schemes both in global and local formulation. Following the latter strategy we adopted the recently introduced Numerator-Denominator Connected expansion (NDC) [ K. Kowalski, P. Piecuch, J. Chem. Phys. 122 (2005) [074107] as an effective tool for designing new forms of noniterative corrections accounting for the joint effect of triples and quadruples. The performance of the ensuing locally renormalized CCSD(TQ) approaches (LR-CCSD(TQ) is illustrated on several examples that require either going beyond the triples approximation or describing very subtle effects encountered in Van der Waals complexes. Comparisons with other noniterative approaches are also made and some issues regarding the size-extensivity of the locally renormalized methods are addressed.

  2. Combustion-related studies using weakly-bonded complexes

    SciTech Connect (OSTI)

    Beaudet, R.A.

    1993-12-01

    Binary van der Waals complexes involving species of interest to combustion research are prepared in supersonic free-jet expansions, and their photochemical and photophysical properties are probed by using IR tunable diode laser (TDL) spectroscopy. In the first phase, geometries and other molecular properties are being determined from vibration-rotational spectra. In the second phase, these complexes will be used as precursors to study photoinitiated reactions in precursor geometry limited environments. Two complementary classes of binary complexes are being investigated. The first involves molecular oxygen and hydrogen containing constituents (e.g. O{sub 2}-HCN, O{sub 2}-HF, O{sub 2}-HCl, O{sub 2}-HBr, O{sub 2}-HI and O{sub 2}-hydrocarbons). These species are interesting candidates for study since upon photodissociating the hydride portion, the reaction H and O{sub 2} via the vibrationally excited HO{sub 2} intermediate can conceivably be studied, (e.g. BrH-O{sub 2} + hv(193 nm) {yields} Br-H-O{sub 2} {yields} Br + HO{sub 2} {yields} Br + OH + O). High resolution IR spectroscopy of such complexes have not been obtained previously and the structural information deriving from IR spectra is certainly very useful for better designing and understanding photoinitiated reactions that occur in these complexes.

  3. Effect of the annealing temperature and ion-beam bombardment on the properties of solution-derived HfYGaO films as liquid crystal alignment layers

    SciTech Connect (OSTI)

    Park, Hong-Gyu; Lee, Yun-Gun; Jang, Sang Bok; Lee, Ju Hwan; Jeong, Hae-Chang; Seo, Dae-Shik; Oh, Byeong-Yun

    2015-11-15

    Hafnium yttrium gallium oxide (HfYGaO) films were applied to liquid crystal displays (LCDs) as liquid crystal (LC) alignment layers, replacing conventional polyimide (PI) layers. The HfYGaO alignment layers were prepared by fabricating solution-processed HfYGaO films, annealing them, and treating them with ion-beam (IB) irradiation. The authors studied the effects of annealing temperature and IB irradiation of the solution-derived HfYGaO films on the orientation of LC molecules. The LC molecules on the solution-derived HfYGaO films were homogeneously and uniformly aligned by IB irradiation, irrespective of the annealing temperature. Atomic force microscopy analyses revealed that the surface reformation of the HfYGaO films induced by IB irradiation strengthened the van der Waals force between the LC molecules and the HfYGaO films, leading to uniform LC alignment. Enhanced electro-optical characteristics were observed in the twisted-nematic (TN) LCDs based on IB-irradiated HfYGaO films compared with those of TN-LCDs based on PI layers, demonstrating the high application potential of the proposed solution-derived HfYGaO films as LC alignment layers.

  4. Growth of Single- and Bilayer ZnO on Au(111) and Interaction with Copper

    SciTech Connect (OSTI)

    Deng, Xingyi; Yao, Kun; Sun, Keju; Li, Wei-Xue; Lee, Junseok; Matranga, Christopher

    2013-05-30

    The stoichiometric single- and bi-layer ZnO(0001) have been prepared by reactive deposition of Zn on Au(111) and studied in detail with X-ray photoelectron spectroscopy, scanning tunneling microscopy, and density functional theory calculations. Both single- and bi-layer ZnO(0001) adopt a planar, graphite-like structure similar to freestanding ZnO(0001) due to the weak van der Waals interactions dominating their adhesion with the Au(111) substrate. At higher temperature, the single-layer ZnO(0001) converts gradually to bi-layer ZnO(0001) due to the twice stronger interaction between two ZnO layers than the interfacial adhesion of ZnO with Au substrate. It is found that Cu atoms on the surface of bi-layer ZnO(0001) are mobile with a diffusion barrier of 0.31 eV, and likely to agglomerate and form nanosized particles at low coverages; while Cu atoms tend to penetrate a single layer of ZnO(0001) with a barrier of 0.10 eV, resulting in a Cu free surface.

  5. Revealing the Preferred Interlayer Orientations and Stackings of Two-Dimensional Bilayer Gallium Selenide Crystals

    SciTech Connect (OSTI)

    Li, Xufan; Basile Carrasco, Leonardo A; Yoon, Mina; Ma, Cheng; Puretzky, Alexander A; Lee, Jaekwang; Idrobo Tapia, Juan Carlos; Chi, Miaofang; Rouleau, Christopher M; Geohegan, David B; Xiao, Kai

    2015-01-01

    Characterizing and controlling the interlayer orientations and stacking order of bilayer two-dimensional (2D) crystals and van der Waals (vdW) heterostructure is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) that result from different layer stacking provide an ideal platform to study the stacking configurations in bilayer 2D crystals. Here, through a controllable vapor-phase deposition method we selectively grow bilayer GaSe crystals and investigate their two preferred 0 or 60 interlayer rotations. The commensurate stacking configurations (AA and AB-stacking) in as-grown 2D bilayer GaSe crystals are clearly observed at the atomic scale and the Ga-terminated edge structure are identified for the first time by using atomic-resolution scanning transmission electron microscopy (STEM). Theoretical analysis of the interlayer coupling energetics vs. interlayer rotation angle reveals that the experimentally-observed orientations are energetically preferred among the bilayer GaSe crystal polytypes. The combined experimental and theoretical characterization of the GaSe bilayers afforded by these growth studies provide a pathway to reveal the atomistic relationships in interlayer orientations responsible for the electronic and optical properties of bilayer 2D crystals and vdW heterostructures.

  6. 2010 Atomic & Molecular Interactions Gordon Research Conference

    SciTech Connect (OSTI)

    Todd Martinez

    2010-07-23

    The Atomic and Molecular Interactions Gordon Conferences is justifiably recognized for its broad scope, touching on areas ranging from fundamental gas phase and gas-condensed matter collision dynamics, to laser-molecule interactions, photophysics, and unimolecular decay processes. The meeting has traditionally involved scientists engaged in fundamental research in gas and condensed phases and those who apply these concepts to systems of practical chemical and physical interest. A key tradition in this meeting is the strong mixing of theory and experiment throughout. The program for 2010 conference continues these traditions. At the 2010 AMI GRC, there will be talks in 5 broadly defined and partially overlapping areas of intermolecular interactions and chemical dynamics: (1) Photoionization and Photoelectron Dynamics; (2) Quantum Control and Molecules in Strong Fields; (3) Photochemical Dynamics; (4) Complex Molecules and Condensed Phases; and (5) Clusters and Reaction Dynamics. These areas encompass many of the most productive and exciting areas of chemical physics, including both reactive and nonreactive processes, intermolecular and intramolecular energy transfer, and photodissociation and unimolecular processes. Gas phase dynamics, van der Waals and cluster studies, laser-matter interactions and multiple potential energy surface phenomena will all be discussed.

  7. Adsorption of dysprosium on the graphite (0001) surface: Nucleation and growth at 300 K

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

    Kwolek, Emma J.; Lei, Huaping; Lii-Rosales, Ann; Wallingford, Mark; Zhou, Yinghui; Wang, Cai -Zhuang; Tringides, Michael C.; Evans, James W.; Thiel, Patricia A.

    2016-06-13

    We have studied nucleation and growth of Dy islands on the basal plane of graphite at 300 K using scanning tunneling microscopy, density functional theory (DFT) in a form that includes van der Waals interactions, and analytic theory. The interaction of atomic Dy with graphite is strong, while the diffusion barrier is small. Experiment shows that at 300 K, the density of nucleated islands is close to the value predicted for homogeneous nucleation, using critical nucleus size of 1 and the DFT-derived diffusion barrier. Homogeneous nucleation is also supported by the monomodal shape of the island size distributions. Comparison withmore » the published island density of Dy on graphene shows that the value is about two orders of magnitude smaller on graphite, which can be attributed to more effective charge screening in graphite. The base of each island is 3 atomic layers high and atomically ordered, forming a coincidence lattice with the graphite. Islands resist coalescence, probably due to multiple rotational orientations associated with the coincidence lattice. Upper levels grow as discernible single-atom layers. Analysis of the level populations reveals significant downward interlayer transport, which facilitates growth of the base. As a result, this island shape is metastable, since more compact three-dimensional islands form at elevated growth temperature.« less

  8. Novel electronic structures of superlattice composed of graphene and silicene

    SciTech Connect (OSTI)

    Yu, S.; Li, X.D. [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Wu, S.Q., E-mail: wsq@xmu.edu.cn [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Wen, Y.H. [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Zhou, S. [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhu, Z.Z., E-mail: zzhu@xmu.edu.cn [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005 (China)

    2014-02-01

    Highlights: Graphene/silicene superlattices exhibit metallic electronic properties. Dirac point of graphene is folded to the ?-point in the superlattice system. Significant changes in the transport properties of the graphene layers are expected. Small amount of charge transfer from the graphene to the silicene layers is found. - Abstract: Superlattice is a major force in providing man-made materials with unique properties. Here we report a study of the structural and electronic properties of a superlattice made with alternate stacking of graphene and hexagonal silicene. Three possible stacking models, i.e., the top-, bridge- and hollow-stacking, are considered. The top-stacking is found to be the most stable pattern. Although both the free-standing graphene and silicene are semi-metals, our results suggest that the graphene and silicene layers in the superlattice both exhibit metallic electronic properties due to a small amount of charge transfer from the graphene to the silicene layers. More importantly, the Dirac point of graphene is folded to the ?-point of the superlattice, instead of the K-point in the isolated graphene. Such a change in the Dirac point of graphene could lead to significant change in the transportation property of the graphene layer. Moreover, the band structure and the charge transfer indicate that the interaction between the stacking sheets in the graphene/silicene superlattice is more than just the van der Waals interaction.

  9. The adsorption properties of CO molecules on single-layer graphene nanoribbons

    SciTech Connect (OSTI)

    Yi, Chenglong; Wang, Weidong, E-mail: wangwd@mail.xidian.edu.cn; Shen, Cuili [School of Electrical and Mechanical Engineering, Xidian University, Xi'an 710071 (China)] [School of Electrical and Mechanical Engineering, Xidian University, Xi'an 710071 (China)

    2014-03-15

    The adsorption properties of CO molecules on graphene nanoribbons (GRNs) are studied through the molecular dynamics (MD) method. The AIREBO and LJ potentials are used to describe the C-C bonds in GNR and the interactions between the carbon atoms in GNR and CO molecules, respectively. The influences of the environmental pressure and charge density on the adsorption properties of CO molecules on GRNs are taken into account in this study. The effects of charges carried by GNRs on the adsorption properties are investigated in two aspects: atom distribution and energy evolution. Its observation from the results shows that the Coulomb force plays a more important role in the adsorption phenomenon than the van der Waals force, and the higher the charge density is, the larger the amount of the adsorbed CO molecules becomes. Low charge densities (<3.291 C/m{sup 2}) do little for the system, that is to say, the GNRs present similar properties to the ones with no charges. However, relatively high charge densities (>4.937 C/m{sup 2}) have an obvious effect on the whole system. The results also indicate that the environmental pressure has great influence on the adsorption properties of COs on GRN, and the higher the pressure is, the greater the adsorption energy becomes.

  10. Atomistic Simulatios of Interfacial Sliding in Amorphous Carbon Nano-composites

    SciTech Connect (OSTI)

    Namilae, Sirish; Radhakrishnan, Balasubramaniam; Gorti, Sarma B

    2007-01-01

    Nanocomposites with amorphous carbon matrix reinforced by hard crystalline nanoparticles are fast developing as next generation super-tough and wear resistant coatings. The frictional wear and toughness properties of these composites are determined by the properties of the interface between crystalline- and amorphous-phases. In this paper we use molecular dynamics and statics simulations to study the interfacial energetics, internal stresses, sliding and friction behavior of diamond- and amorphous-carbon interfaces. It is found that the orientation of crystalline phase has minor effect on sliding behavior. Sliding behavior is affected by two mechanisms (1) bond breaking and reattaching at the interface and (2) deformation of amorphous carbon in the region surrounding the interface. It is found that the deformation away from the interface reduces the resistance to sliding. In structures with higher SP3 content, bond breaking at the interface dominates and there is much lesser deformation in the amorphous phase. The frictional resistance is significantly less if the interfacial bonding is primarily due to the Van Der Waal's interactions.

  11. The Role of Non-Bonded Interactions in the Conformational Dynamics of Organophosphorous Hydrolase Adsorbed onto Functionalized Mesoporous Silica Surfaces

    SciTech Connect (OSTI)

    Gomes, Diego Enry B.; Lins, Roberto D.; Pascutti, Pedro G.; Lei, Chenghong; Soares, Thereza A.

    2010-01-14

    The enzyme organophosphorous hydrolase (OPH) catalyzes the hydrolysis of a wide variety of organophosphorous compounds with high catalytic efficiency and broad substrate specificity. The immobilization of OPH in functionalized mesoporous silica surfaces increases significantly its catalytic specific activity compared to the enzyme in solution with important applications for the detection and decontamination of insecticides and chemical warfare agents. Experimental measurements of immobilization efficiency as function of the charge and coverage percentage of different functional groups have been interpreted as electrostatic forces being the predominant interactions underlying the adsorption of OPH onto functionalized mesoporous silica surfaces. Explicit solvent molecular dynamics simulations have been performed for OPH in bulk solution and adsorbed onto two distinct interaction potential models of the mesoporous silica functional groups in order to investigate the relative contributions of non-bonded interactions to the conformational dynamics and adsorption of the protein. Our results support the conclusion that while electrostatic interactions are responsible for the specific binding of OPH to the FMS surface, van der Waals forces are detrimental for enhanced interfacial adhesion. Key-words: molecular dynamics simulations; bacterial phosphotriesterase; conformational changes; confined environments; coarse-grain and atomistic models; silanol molecular model.

  12. Infrared spectroscopy and structure of (NO)n clusters

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

    Hoshina, Hiromichi; Slipchenko, Mikhail; Prozument, Kirill; Verma, Deepak; Schmidt, Michael W.; Ivanic, Joseph; Vilesov, Andrey F.

    2016-01-12

    Nitrogen oxide clusters (NO)n have been studied in He droplets via infrared depletion spectroscopy and by quantum chemical calculations. The ν1 and ν5 bands of cis-ON-NO dimer have been observed at 1868.2 and 1786.5 cm–1, respectively. Furthermore, spectral bands of the trimer and tetramer have been located in the vicinity of the corresponding dimer bands in accord with computed frequencies that place NO-stretch bands of dimer, trimer, and tetramer within a few wavenumbers of each other. In addition, a new line at 1878.1 cm–1 close to the band origin of single molecules was assigned to van der Waals bound dimersmore » of (NO)2, which are stabilized due to the rapid cooling in He droplets. Spectra of larger clusters (n > 5), have broad unresolved features in the vicinity of the dimer bands. As a result, experiments and calculations indicate that trimers consist of a dimer and a loosely bound third molecule, whereas the tetramer consists of two weakly bound dimers.« less

  13. Conduction mechanisms in ion-irradiated InGaAs layers

    SciTech Connect (OSTI)

    Joulaud, L.; Mangeney, J.; Chimot, N.; Crozat, P.; Fishman, G.; Bourgoin, J.C.

    2005-03-15

    The electrical and optical properties of H{sup +}- and Au{sup +}-irradiated InGaAs layers were studied using Hall-effect, van der Pauw, and relaxation-time measurements. Comparing the different results allows us to obtain information on the nature of the defects created by these two irradiations. Proton irradiation introduces donor-acceptor paired defects. Gold-ion irradiation creates neutral defect clusters and ionized point defects. The carrier mobilities in all of the irradiated materials are degraded, decreasing with increasing irradiation dose. A scattering model taking into account the paired defects is developed and the mobility evolution calculated from this model agrees with the experimental data of both annealed and unannealed samples. The photocurrent spectra reveal a metallic conduction in the band gap in the case of light-ion irradiation, while such type of conduction does not appear for heavy-ion irradiation. This metallic conduction is a consequence of band tailing induced by shallow defects and vanishes when the material is annealed at 400 deg. C. The proton irradiation-induced defects appear to be related to the EL-2-like defects.

  14. Development of ab initio techniques critical for future science-based explosives R&D.

    SciTech Connect (OSTI)

    Wixom, Ryan R.; Mattsson, Ann Elisabet

    2013-10-01

    Density Functional Theory (DFT) has emerged as an indispensable tool in materials research, since it can accurately predict properties of a wide variety of materials at both equilibrium and extreme conditions. However, for organic molecular crystal explosives, successful application of DFT has largely failed due to the inability of current exchange-correlation functionals to correctly describe intermolecular van der Waals' (vdWs) forces. Despite this, we have discovered that even with no treatment of vdWs bonding, the AM05 functional and DFT based molecular dynamics (MD) could be used to study the properties of molecular crystals under compression. We have used DFT-MD to predict the unreacted Hugoniots for PETN and HNS and validated the results by comparison with crystalline and porous experimental data. Since we are also interested in applying DFT methods to study the equilibrium volume properties of explosives, we studied the nature of the vdWs bonding in pursuit of creating a new DFT functional capable of accurately describing equilibrium bonding of molecular crystals. In this report we discuss our results for computing shock Hugoniots of molecular crystals and also what was learned about the nature of bonding in these materials.

  15. Recent Advances in Two-Dimensional Materials Beyond Graphene

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

    Meunier, Vincent; Sumpter, Bobby G.; Terrones Maldonado, Mauricio; Terrones Maldonado, Humberto; Liang, Liangbo; Cooper, Valentino R.; Bhimanapati, Ganesh; Lin, Zhong; Jung, Yeongwoong; Cha, Judy; et al

    2015-11-06

    The isolation of graphene in 2004 by peeling apart the atomically-thin sheets that comprise graphite was a defining moment for the birth of a field: Two-dimensional (2D) materials. In recent years, there has been a rapidly increasing number of papers focusing on non-graphene layered materials, including transition-metal dichalcogenides (TMDs), because of the new properties and applications that emerge upon 2D confinement. Here we review significant recent advances and important new developments in 2D materials beyond graphene . We provide insight into the theoretical modeling and understanding of the van der Waals forces that hold together the 2D layers in bulkmore » solids, as well as their excitonic properties and growth morphologies. Additionally, we highlight recent breakthroughs in TMD synthesis and characterization and discuss the newest families of 2D materials, including monoelement 2D materials (i.e., silicene, phosphorene, etc.) and transition metal carbide- and carbon nitride-based MXenes. We then discuss the doping and functionalization of 2D materials beyond graphene, which enable device applications, followed by advances in electronic, optoelectronic, and magnetic devices and theory. Finally, we provide perspectives on the future of 2D materials beyond graphene.« less

  16. Metalized T graphene: A reversible hydrogen storage material at room temperature

    SciTech Connect (OSTI)

    Ye, Xiao-Juan; Zhong, Wei, E-mail: csliu@njupt.edu.cn, E-mail: wzhong@nju.edu.cn; Du, You-Wei [Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093 (China); Liu, Chun-Sheng, E-mail: csliu@njupt.edu.cn, E-mail: wzhong@nju.edu.cn [Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Zeng, Zhi [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2014-09-21

    Lithium (Li)-decorated graphene is a promising hydrogen storage medium due to its high capacity. However, homogeneous mono-layer coating graphene with lithium atoms is metastable and the lithium atoms would cluster on the surface, resulting in the poor reversibility. Using van der Waals-corrected density functional theory, we demonstrated that lithium atoms can be homogeneously dispersed on T graphene due to a nonuniform charge distribution in T graphene and strong hybridizations between the C-2p and Li-2p orbitals. Thus, Li atoms are not likely to form clusters, indicating a good reversible hydrogen storage. Both the polarization mechanism and the orbital hybridizations contribute to the adsorption of hydrogen molecules (storage capacity of 7.7 wt. %) with an optimal adsorption energy of 0.19 eV/H?. The adsorption/desorption of H? at ambient temperature and pressure is also discussed. Our results can serve as a guide in the design of new hydrogen storage materials based on non-hexagonal graphenes.

  17. Task-parallel message passing interface implementation of Autodock4 for docking of very large databases of compounds using high-performance super-computers

    SciTech Connect (OSTI)

    Collignon, Barbara C; Schultz, Roland; Smith, Jeremy C; Baudry, Jerome Y

    2011-01-01

    A message passing interface (MPI)-based implementation (Autodock4.lga.MPI) of the grid-based docking program Autodock4 has been developed to allow simultaneous and independent docking of multiple compounds on up to thousands of central processing units (CPUs) using the Lamarkian genetic algorithm. The MPI version reads a single binary file containing precalculated grids that represent the protein-ligand interactions, i.e., van der Waals, electrostatic, and desolvation potentials, and needs only two input parameter files for the entire docking run. In comparison, the serial version of Autodock4 reads ASCII grid files and requires one parameter file per compound. The modifications performed result in significantly reduced input/output activity compared with the serial version. Autodock4.lga.MPI scales up to 8192 CPUs with a maximal overhead of 16.3%, of which two thirds is due to input/output operations and one third originates from MPI operations. The optimal docking strategy, which minimizes docking CPU time without lowering the quality of the database enrichments, comprises the docking of ligands preordered from the most to the least flexible and the assignment of the number of energy evaluations as a function of the number of rotatable bounds. In 24 h, on 8192 high-performance computing CPUs, the present MPI version would allow docking to a rigid protein of about 300K small flexible compounds or 11 million rigid compounds.

  18. Backbone N{sub x}H compounds at high pressures

    SciTech Connect (OSTI)

    Goncharov, Alexander F.; Holtgrewe, Nicholas; Qian, Guangrui; Hu, Chaohao; Oganov, Artem R.; Somayazulu, Maddury; Stavrou, Elissaios; Pickard, Chris J.; and others

    2015-06-07

    Optical and synchrotron x-ray diffraction diamond anvil cell experiments have been combined with first-principles theoretical structure predictions to investigate mixtures of N{sub 2} and H{sub 2} up to 55 GPa. Our experiments show the formation of structurally complex van der Waals compounds [see also D. K. Spaulding et al., Nat. Commun. 5, 5739 (2014)] above 10 GPa. However, we found that these N{sub x}H (0.5 < x < 1.5) compounds transform abruptly to new oligomeric materials through barochemistry above 47 GPa and photochemistry at pressures as low as 10 GPa. These oligomeric compounds can be recovered to ambient pressure at T < 130 K, whereas at room temperature, they can be metastable on pressure release down to 3.5 GPa. Extensive theoretical calculations show that such oligomeric materials become thermodynamically more stable in comparison to mixtures of N{sub 2}, H{sub 2}, and NH{sub 3} above approximately 40 GPa. Our results suggest new pathways for synthesis of environmentally benign high energy-density materials. These materials could also exist as alternative planetary ices.

  19. Strong anisotropy and magnetostriction in the two-dimensional Stoner ferromagnet Fe3GeTe2

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

    Zhuang, Houlong L.; Kent, P. R. C.; Hennig, Richard G.

    2016-04-06

    Comore » mputationally characterizing magnetic properies of novel two-dimensional (2D) materials serves as an important first step of exploring possible applications. Using density-functional theory, we show that single-layer Fe3GeTe2 is a potential 2D material with sufficiently low formation energy to be synthesized by mechanical exfoliation from the bulk phase with a van der Waals layered structure. In addition, we calculated the phonon dispersion demonstrating that single-layer Fe3GeTe2is dynamically stable. Furthermore, we find that similar to the bulk phase, 2D Fe3GeTe2 exhibits amagnetic moment that originates from a Stoner instability. In contrast to other 2D materials, we find that single-layer Fe3GeTe2 exhibits a significant uniaxial magnetocrystalline anisotropy energy of 920μ eV per Fe atom originating from spin-orbit coupling. In conclusion, we show that applying biaxial tensile strains enhances the anisotropy energy, which reveals strong magnetostriction in single-layer Fe3GeTe2 with a sizable magneostrictive coefficient. Our results indicate that single-layer Fe3GeTe2 is potentially useful for magnetic storage applications.« less

  20. Large anomalous Hall effect in ferromagnetic insulator-topological insulator heterostructures

    SciTech Connect (OSTI)

    Alegria, L. D.; Petta, J. R.; Ji, H.; Cava, R. J.; Yao, N.; Clarke, J. J.

    2014-08-04

    We demonstrate the van der Waals epitaxy of the topological insulator compound Bi{sub 2}Te{sub 3} on the ferromagnetic insulator Cr{sub 2}Ge{sub 2}Te{sub 6}. The layers are oriented with (001)Bi{sub 2}Te{sub 3}||(001)Cr{sub 2}Ge{sub 2}Te{sub 6} and (110)Bi{sub 2}Te{sub 3}||(100)Cr{sub 2}Ge{sub 2}Te{sub 6}. Cross-sectional transmission electron microscopy indicates the formation of a sharp interface. At low temperatures, bilayers consisting of Bi{sub 2}Te{sub 3} on Cr{sub 2}Ge{sub 2}Te{sub 6} exhibit a large anomalous Hall effect (AHE). Tilted field studies of the AHE indicate that the easy axis lies along the c-axis of the heterostructure, consistent with magnetization measurements in bulk Cr{sub 2}Ge{sub 2}Te{sub 6}. The 61 K Curie temperature of Cr{sub 2}Ge{sub 2}Te{sub 6} and the use of near-stoichiometric materials may lead to the development of spintronic devices based on the AHE.

  1. Stochastic bifurcation and fractal and chaos control of a giant magnetostrictive film-shape memory alloy composite cantilever plate subjected to in-plane harmonic and stochastic excitation

    SciTech Connect (OSTI)

    Zhu, Zhiwen; Zhang, Qingxin Xu, Jia

    2014-05-07

    Stochastic bifurcation and fractal and chaos control of a giant magnetostrictive filmshape memory alloy (GMFSMA) composite cantilever plate subjected to in-plane harmonic and stochastic excitation were studied. Van der Pol items were improved to interpret the hysteretic phenomena of both GMF and SMA, and the nonlinear dynamic model of a GMFSMA composite cantilever plate subjected to in-plane harmonic and stochastic excitation was developed. The probability density function of the dynamic response of the system was obtained, and the conditions of stochastic Hopf bifurcation were analyzed. The conditions of noise-induced chaotic response were obtained in the stochastic Melnikov integral method, and the fractal boundary of the safe basin of the system was provided. Finally, the chaos control strategy was proposed in the stochastic dynamic programming method. Numerical simulation shows that stochastic Hopf bifurcation and chaos appear in the parameter variation process. The boundary of the safe basin of the system has fractal characteristics, and its area decreases when the noise intensifies. The system reliability was improved through stochastic optimal control, and the safe basin area of the system increased.

  2. Fluid Phase Lipid Areas and Bilayer Thicknesses of Commonly Used Phosphatidylcholines as a Function of Temperature

    SciTech Connect (OSTI)

    Kucerka, Norbert; Nieh, Mu-Ping; Katsaras, John

    2011-01-01

    The structural parameters of fluid phase bilayers composed of phosphatidylcholines with fully saturated, mixed, and branched fatty acid chains, at several temperatures, have been determined by simultaneously analyzing small-angle neutron and X-ray scattering data. Bilayer parameters, such as area per lipid and overall bilayer thickness have been obtained in conjunction with intrabilayer structural parameters (e.g. hydrocarbon region thickness). The results have allowed us to assess the effect of temperature and hydrocarbon chain composition on bilayer structure. For example, we found that for all lipids there is, not surprisingly, an increase in fatty acid chain trans-gauche isomerization with increasing temperature. Moreover, this increase in trans-gauche isomerization scales with fatty acid chain length in mixed chain lipids. However, in the case of lipids with saturated fatty acid chains, trans-gauche isomerization is increasingly tempered by attractive chain-chain van der Waals interactions with increasing chain length. Finally, our results confirm a strong dependence of lipid chain dynamics as a function of double bond position along fatty acid chains.

  3. Real-time observation of epitaxial graphene domain reorientation

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

    Thuermer, Konrad; Foster, Michael E.; Bartelt, Norman Charles; Rogge, Paul C.; Lawrence Berkeley National Lab.; McCarty, Kevin F.; Dubon, Oscar D.; Lawrence Berkeley National Lab.; Bartelt, Norman C.

    2015-04-20

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, ‘ripening’; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV permore » C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene–substrate interaction reproduces the results. This study suggests new strategies for improving the van der Waals epitaxy of 2D materials.« less

  4. Real-time observation of epitaxial graphene domain reorientation

    SciTech Connect (OSTI)

    Thuermer, Konrad; Foster, Michael E.; Bartelt, Norman Charles; Rogge, Paul C.; McCarty, Kevin F.; Dubon, Oscar D.; Bartelt, Norman C.

    2015-04-20

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, ‘ripening’; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV per C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene–substrate interaction reproduces the results. This study suggests new strategies for improving the van der Waals epitaxy of 2D materials.

  5. Tunable Polarity Behavior and Self-Driven Photoswitching in p-WSe2/n-WS2 Heterojunctions

    SciTech Connect (OSTI)

    Huo, Nengjie; Yang, Juehan; Huang, Le; Wei, Zhongming; Li, Shu-Shen; Wei, Su-Huai; Li, Jingbo

    2015-08-21

    In Van der Waals (vdW) p–n heterojunctions consisting of various 2D layer compounds are fascinating new artificial materials that can possess novel physics and functionalities enabling the next-generation of electronics and optoelectronics devices. Here, it is reported that the WSe2/WS2 p–n heterojunctions perform novel electrical transport properties such as distinct rectifying, ambipolar, and hysteresis characteristics. Intriguingly, the novel tunable polarity transition along a route of n-“anti-bipolar”–p-ambipolar is observed in the WSe2/WS2 heterojunctions owing to the successive work of conducting channels of junctions, p-WSe2 and n-WS2 on the electrical transport of the whole systems. Moreover, the type-II band alignment we obtained from first principle calculations and built-in potential in this vdW heterojunction can also facilitate the efficient electron–hole separation, thus enabling the significant photovoltaic effect and a much enhanced self-driven photoswitching response in this system.

  6. Photon induced Schottky barrier effects in inverse-extraordinary optoconductance structures

    SciTech Connect (OSTI)

    Tran, L.; Solin, S. A.; Gilbertson, A.; Cohen, L. F.

    2013-12-04

    We expand upon our previous work and characterize the photo-dependence of the effective Schottky barrier in EOC and I-EOC heterostructures by measuring the open circuit voltage and the change in the reverse bias resistance. Under full illumination by a 5 mW, 632.8 nm HeNe laser, the barrier is effectively eliminated and the Ti-GaAs interface becomes Ohmic. The reverse bias resistance changes by a factor of 209 over an illumination intensity change of 105:1. While this work illustrates the behavior of the Schottky interface upon illumination, it also demonstrates the effectiveness of the four-point, van der Pauw measurement fundamental to EOC/I-EOC phenomena at monitoring changes in the active region of the mesa. The resistance is largely unaffected by the photovoltaic, DC offset of the surrounding leads, as indicated by the radial symmetry of 2-D resistance maps obtained by rastering the laser across EOC/IEOC devices.

  7. Interplay between intercalated oxygen superstructures and monolayer h -BN on Cu(100)

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

    Ma, Chuanxu; Park, Jewook; Liu, Lei; Kim, Yong-Sung; Yoon, Mina; Baddorf, Arthur P.; Gu, Gong; Li, An-Ping

    2016-08-18

    The confinement effect of intercalated atoms in van der Waals heterostructures can lead to interesting interactions between the confined atoms or molecules and the overlaying two-dimensional (2D) materials. In this paper, we report the formation of ordered Cu(100) p(2×2) oxygen superstructures by oxygen intercalation under the monolayer hexagonal boron nitride (h-BN) on Cu after annealing. By using scanning tunneling microscopy and x-ray photoelectron spectroscopy, we identify the superstructure and reveal its roles in passivating the exposed Cu surfaces, decoupling h-BN and Cu, and disintegrating h-BN monolayers. The oxygen superstructure appears as a 2D pattern on the exposed Cu surface ormore » quasi-1D stripes of paired oxygen intercalated in the interface of h-BN and Cu predominantly oriented along the moiré modulations. The oxygen superstructure is shown to etch the overlaying h-BN monolayer in a thermal annealing process. After extended annealing, the h-BN monolayer disintegrates into nanoislands with zigzag edges. Finally, we discuss the implications of these findings on the stability and oxidation resistance of h-BN and relate them to challenges in process integration and 2D heterostructures.« less

  8. Organic molecules deposited on graphene: A computational investigation of self-assembly and electronic structure

    SciTech Connect (OSTI)

    Oliveira, I. S. S. de; Miwa, R. H.

    2015-01-28

    We use ab initio simulations to investigate the adsorption and the self-assembly processes of tetracyanoquinodimethane (TCNQ), tetrafluoro-tetracyanoquinodimethane (F4-TCNQ), and tetrasodium 1,3,6,8-pyrenetetrasulfonic acid (TPA) on the graphene surface. We find that there are no chemical bonds at the moleculegraphene interface, even at the presence of grain boundaries on the graphene surface. The molecules bond to graphene through van der Waals interactions. In addition to the moleculegraphene interaction, we performed a detailed study of the role played by the (lateral) moleculemolecule interaction in the formation of the, experimentally verified, self-assembled layers of TCNQ and TPA on graphene. Regarding the electronic properties, we calculate the electronic charge transfer from the graphene sheet to the TCNQ and F4-TCNQ molecules, leading to a p-doping of graphene. Meanwhile, such charge transfer is reduced by an order of magnitude for TPA molecules on graphene. In this case, it is not expected a significant doping process upon the formation of self-assembled layer of TPA molecules on the graphene sheet.

  9. Recent Advances in Two-Dimensional Materials Beyond Graphene

    SciTech Connect (OSTI)

    Meunier, Vincent; Sumpter, Bobby G.; Terrones Maldonado, Mauricio; Terrones Maldonado, Humberto; Liang, Liangbo; Cooper, Valentino R.; Bhimanapati, Ganesh; Lin, Zhong; Jung, Yeongwoong; Cha, Judy; Das, Saptarshi; Xiao, Di; Son, Youngwoo; Strano, Michael; Louie, Steven G.; Ringe, Emilie; Xia, Fengnian; Wang, Yeliang; Akinwande, Deji; Zhu, Jun; Schuller, John; Schaak, Raymond; Robinson, Joshua A

    2015-11-06

    The isolation of graphene in 2004 by peeling apart the atomically-thin sheets that comprise graphite was a defining moment for the birth of a field: Two-dimensional (2D) materials. In recent years, there has been a rapidly increasing number of papers focusing on non-graphene layered materials, including transition-metal dichalcogenides (TMDs), because of the new properties and applications that emerge upon 2D confinement. Here we review significant recent advances and important new developments in 2D materials beyond graphene . We provide insight into the theoretical modeling and understanding of the van der Waals forces that hold together the 2D layers in bulk solids, as well as their excitonic properties and growth morphologies. Additionally, we highlight recent breakthroughs in TMD synthesis and characterization and discuss the newest families of 2D materials, including monoelement 2D materials (i.e., silicene, phosphorene, etc.) and transition metal carbide- and carbon nitride-based MXenes. We then discuss the doping and functionalization of 2D materials beyond graphene, which enable device applications, followed by advances in electronic, optoelectronic, and magnetic devices and theory. Finally, we provide perspectives on the future of 2D materials beyond graphene.

  10. Exhaust Gas Recirculation Cooler Fouling in Diesel Applications: Fundamental Studies Deposit Properties and Microstructure

    SciTech Connect (OSTI)

    Storey, John Morse; Sluder, Scott; Lance, Michael J; Styles, Dan; Simko, Steve

    2013-01-01

    This paper reports on the results of experimental efforts aimed at improving the understanding of the mechanisms and conditions at play in the fouling of EGR coolers. An experimental apparatus was constructed to utilize simplified surrogate heat exchanger tubes in lieu of full-size heat exchangers. The use of these surrogate tubes allowed removal of the tubes after exposure to engine exhaust for study of the deposit layer and its properties. The exhaust used for fouling the surrogate tubes was produced using a modern medium-duty diesel engine fueled with both ultra-low sulfur diesel and biodiesel blends. At long exposure times, no significant difference in the fouling rate was observed between fuel types and HC levels. Surface coatings for the tubes were also evaluated to determine their impact on deposit growth. No surface treatment or coating produced a reduction in the fouling rate or any evidence of deposit removal. In addition, microstructural analysis of the fouling layers was performed using optical and electron microscopy in order to better understand the deposition mechanism. The experimental results are consistent with thermophoretic deposition for deposit formation, and van der Waals attraction between the deposit surface and exhaust-borne particulate.

  11. 2D-network of inorganic-organic hybrid material built on Keggin type polyoxometallate and amino acid: [L-C{sub 2}H{sub 6}NO{sub 2}]{sub 3}[(PO{sub 4})Mo{sub 12}O{sub 36}].5H{sub 2}O

    SciTech Connect (OSTI)

    Alizadeh, M.H. Mirzaei, M.; Razavi, H.

    2008-03-04

    A new inorganic-organic hybrid material based on polyoxometallate, [L-C{sub 2}H{sub 6}NO{sub 2}]{sub 3}[(PO{sub 4})Mo{sub 12}O{sub 36}].5H{sub 2}O, has been successfully synthesized and characterized by single-crystal X-ray analysis, elemental analysis, infrared and ultraviolet spectroscopy, proton nuclear magnetic resonance and differential thermal analysis techniques. The title compound crystallizes in the monoclinic space group, P2{sub 1}/c{sub ,} with a = 12.4938 (8) A, b = 19.9326 (12) A, c = 17.9270 (11) A, {beta} = 102.129 (1){sup o}, V = 4364.8 (5) A{sup 3}, Z = 4 and R{sub 1}(wR{sub 2}) = 0.0513, 0.0877. The most remarkable structural feature of this hybrid can be described as two-dimensional inorganic infinite plane-like (2D/{infinity} [(PO{sub 4})Mo{sub 12}O{sub 36}]{sup 3-}) which forming via weak Van der Waals interactions along the z axis. The characteristic band of the Keggin anion [(PO{sub 4})Mo{sub 12}O{sub 36}]{sup 3-} appears at 210 nm in the UV spectrum. Thermal analysis indicates that the Keggin anion skeleton begins to decompose at 520 deg. C.

  12. Before the Senate Energy and Natural Resources Committee

    Broader source: Energy.gov [DOE]

    Subject: Carbon Capture, Transportation and Storage By: Victor Der, Acting Assistant Secretary, Office of Fossil Energy

  13. Before the House Science, Space, and Technology Subcommittee on Energy and Environment

    Broader source: Energy.gov [DOE]

    Subject: Offshore Drilling Safety and Response Technologies By: Victor Der, Assistant Secretary Office of Fossil Energy

  14. Using Distributed Energy Resources, A How-To Guide for Federal Facility Managers

    SciTech Connect (OSTI)

    Distributed Utility Associates

    2002-05-01

    The Department of Energy's Federal Energy Management Program (FEMP) established the Distributed Energy Resources (DER) Program to assist Federal agencies in implementing DER projects at their facilities. FEMP prepared this How-To Guide to assist facility managers in evaluating potential applications and benefits. It provides step-by-step advice on how to carry out a Federal DER project. It also describes and explains DER applications and potential benefits in Federal facilities; DER technologies and how to match them to applications; a step-by-step approach to implementing projects; potential barriers and how to overcome them; and resources to assist you in implementing new DER projects.

  15. BPA-2011-00611-FOIA Correspondence

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

    contracts between BPA and former vice president Vickie VanZandt or her firm, VanZandt Electric Transmission Consulting, Inc., September 1, 2009. 2. The sole-source...

  16. BPA-2011-00611-FOIA Response

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

    contracts between BPA and former vice President Vickie VanZandt or her firm, VanZandt Electric Transmission Consulting, Inc., since September 1, 2009. 2. The sole-source...

  17. Freedom of Information Act Response

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

    6, 2010 In reply refer to: DK-7 Richard van Dijk Another Way BPA Ex 6 RE: BPA-2010-01870-F Dear Mr. van Dijk: This is a partial release of the information you requested under...

  18. Aeroelastic Modeling of Large Off-shore Vertical-axis Wind Turbines...

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

    ... K. Dixon, C. Ferreira, C. Hofemann, G. van Bussel, and G. van Kuik, "A 3D unsteady panel method for vertical axis wind turbines," Proceedings of the European Wind Energy ...

  19. Preparation of Papers for AIAA Technical Conferences

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

    ... K. Dixon, C. Ferreira, C. Hofemann, G. van Bussel, and G. van Kuik, "A 3D unsteady panel method for vertical axis wind turbines," Proceedings of the European Wind Energy ...

  20. Fermilab | Newsroom | Press Releases | March 18, 2014: Edward...

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

    After Feynman's death in 1988, Leighton inherited the van and used it in 1993 to transport the Tuvan throat singers during their first tour of California. The Feynman van,...

  1. European Wind Energy Conference Exhibition

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

    ... Van Dam et. al. 5-7, have investigated, both computationally with CFD investigations and ... Figure 2. Microtab concept based on Kutta Condition (van Dam 18) The specific microtab ...

  2. Active Aerodynamic Blade Distributed Flap Control Design Procedure

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

    ... Van Dam et. al., 2-4 have investigated, both computationally with CFD investigations and ... Ca., June 4-6, 2007. 2 Yen, D., van Dam, C.P., Smith, R.L. and Collins, S.D., ...

  3. Microsoft PowerPoint - AWEA08-pitch1.ppt

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

    Acknowledgments Acknowledgments UC Davis UC Davis - - Professor Case van Dam Professor Case van Dam - - M. Leal M. Leal - - J.P. Baker J.P. Baker Sandia National Laboratories ...

  4. EWEC Paper … December 3, 2008

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

    ... turbine blade load control has recently been compiled by Johnson, van Dam and Berg 3. ... 8-11 January, 2007. 3. Johnson, Scott, van Dam, C.P. (Case), and Berg, Dale, 2008, "Active ...

  5. Optimized Active Aerodynamic Blade Control

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

    ... loads and increased energy capture. van Dam et. al., 4-6 has investigated both ... In reference 9 van Dam, et.al. have developed a microtab wing section for wind tunnel ...

  6. Field Test Results from the Sandia SMART Rotor

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

    back to collaborations with C.P. van Dam and R. Chow on the microtab device concept ... from Wind, 2010. 18 Chow, R., and van Dam, C.P., "Unsteady Computational ...

  7. BPA-2013-01714-FOIA Correspondence

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

    Richard van Dijk Another Way BPA PO Box 820152 Vancouver, WA 98682 FOIA BPA-2013-01714-F Dear Mr. van Dijk: Thank you for your request for records that you made to the Bonneville...

  8. BPA-2011-00359-FOIA Correspondence

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

    's of PUBLIC AFFAIRS December 14. 2010 In reply refer to: DK-7 Richard van Dijk Another Way BPA P.O. Box 820152 Vancouver, WA 98682 RE: BPA-2011-00359-F Dear Mr. van...

  9. BPA-2012-00009-Consult Response

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

    1 In reply refer to: DK-7 Mr. Richard van Dijk Ex 6 RE: FOIA BPA-2012-00009-C Dear Mr. van Dijk: This is a final response to your Freedom of Information Act (FOIA) request to...

  10. Bonneville Power Administration

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

    December 20. 2010 In reply refer to: DK-7 Mr. Richard van Dijk Another Way BPA RE: FOIA BPA-2011-00126-F Dear Mr. van Dijk: This is a final response to your request lUr...

  11. BPA-2011-01630-FOIA Response

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

    Oregon 97208-3621 PUBLIC AFFAIRS October 8, 2011 In reply refer to: DK-7 Richard van Dijk FOIA BPA-2011-01630-F Dear Mr. van Dijk: This is a partial response to your request...

  12. BPA-2011-01635-FOIA Correspondence

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

    Oregon 97208-3621 PUBLIC AFFAIRS August 8, 2011 In reply refer to: DK-7 Richard van Dijk Another Way BPA FOIA BPA-2011-01635-F Dear Mr. van Dijk: Thank you for your request...

  13. BPA-2011-00358-FOIA Response

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

    5, 2011 In reply refer to: DK-7 Richard van Dijk Another Way BPA Ex 6 RE: BPA-2011-00358-F Dear Mr. van Dijk: This is a final response to your request for information that you made...

  14. BPA-2012-00235-FOIA Correspondence

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

    Oregon 97208-3621 PUBLIC AFFAIRS December 7, 2011 In reply refer to: DK-7 Richard van Dijk Ex 6 FOIA BPA-2012-00235-F Dear Mr. van Dijk: Bonneville Power Administration (BPA) is...

  15. BPA-2014-00700-FOIA Correspondence

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

    Richard van Dijk Ex 6 FOIA BPA-2014-00700-F Dear Mr. van Dijk: Thank you for your request for records that you made to the Bonneville Power Administration (BPA), under the Freedom...

  16. BPA-2011-01732-FOIA Correspondence

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

    ' 91 ES O F P PUBLIC AFFAIRS August 30, 2011 In reply refer to: DK-7 Richard van Dijk FOIA BPA-2011-01732-F Dear Mr. van Dijk: Thank you for your request for records that...

  17. BPA-2011-01631-FOIA Response

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

    7, 2011 In reply refer to: DK-7 Richard van Dijk Ex 6 FOIA BPA-2011-01631-F Dear Mr. van Dijk: This is a final response to your request for records that you made to the Bonneville...

  18. BPA-2011-00358-FOIA Correspondence

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

    4, 2010 In reply refer to: DK-7 Richard van Dijk Another Way BPA Ex 6 RE: BPA-2011-00358-F Dear Mr. van Dijk: Thank you for your request for information that you made to the...

  19. Microsoft Word - ExLtr.doc

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

    8, 2013 In reply refer to: DK-7 Richard van Dijk Another Way BPA PO Box 820152 Vancouver, WA 98682 FOIA BPA-2013-00361-F Dear Mr. van Dijk: Bonneville Power Administration (BPA)...

  20. BPA-2012-00009-C FOIA Correspondence

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

    11, 2011 In reply refer to: DK-7 Richard van Dijk Another Way BPA Ex 6 FOIA BPA-2011-00009-C Dear Mr. van Dijk: This letter is in response to a FOIA request that you sent to the...

  1. BPA-2013-01712-FOIA Correspondence

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

    AND CONTINUITY OF OPERATIONS September 20, 2013 In reply refer to: NN- 1 Richard van Dijk Another Way BPA P0 Box 820152 Vancouver, WA 98682 FOIA BPA-2013-01712-F Dear Mr. van...

  2. BPA-2011-01634-FOIA Correspondence

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

    97208-3621 esoF PUBLIC AFFAIRS August 9, 2011 In reply refer to: DK-7 Richard van Dijk Another Way BPA FOIA BPA-2011-01634-F Dear Mr. van Dijk: Thank you for your request...

  3. BPA-2011-00121 FOIA Response

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

    10 In reply refer to: DK-7 Mr. Richard van Dijk Another Way BPA Ex 6 RE: FOIA BPA-2011-00121-F Dear Mr. van Dijk: This is a final response to your request for information that you...

  4. BPA-2010-00122-FOIA Response

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

    Mr. Richard van Dijk Another Way BPA P.O. Box 820152 Vancouver, WA 98682 RE: FOIA BPA-2011-00122-F Dear Mr. van Dijk: This is a final response to your request for information...

  5. BPA-2011-00121-FOIA Correspondence

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

    November 18, 2010 In reply refer to: DK-7 Mr. Richard van Dijk: Another Way BPA Ex 6 RE: BPA-2011-00121-F Dear Mr. van Dijk: Bonneville Power Administration is taking an allowed...

  6. BPA-2011-01634-FOIA Response

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

    Oregon 97208-3621 PUBLIC AFFAIRS August 30, 2011 In reply refer to: DK-7 Richard van Dijk FOIA BPA-2011-01634-F Dear Mr. van Dijk: This is a final response to your request for...

  7. BPA-2011-01780-FOIA Correspondence

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

    T ES O F P PUBLIC AFFAIRS August 31, 2011 In reply refer to: DK-7 Richard van Dijk FOIA BPA-2011-01780-F Dear Mr. van Dijk: Thank you for your request for records that...

  8. BPA-2010-00493-FOIA Correspondence

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

    Richard van Dijk 19521 NE 212 th Ave Brush Prairie, WA 98606 In reply refer to: DK-7 FOIA BPA 2010-00493-F Dear Mr. van Dijk: Thank you for the request for information that you...

  9. Bonneville Power Administration

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

    DK-7 Mr. Richard van C)ijk Another Way BPA Ex 6 RE: FOIA BPA-2012-00294-F Dear Mr. van Dijk: This is a final response to your request for information that you made to the...

  10. BPA-2012-00238-FOIA Correspondence

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

    Oregon 97208-3621 PUBLIC AFFAIRS December 7, 2011 In reply refer to: DK-7 Richard van Dijk Another Way BPA Ex 6 FOIA BPA-2012-00238-F Dear Mr. van Dijk: Bonneville Power...

  11. BPA-2011-01636-FOIA Response

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

    97208-3621 P PUBLIC AFFAIRS August 23, 2011 In reply refer to: DK-7 Richard van Dijk FOIA BPA-2011-01636-F Dear Mr. van Dijk: This is a final response to your request for...

  12. BPA-2011-01630-FOIA Correspondence

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

    97208-3621 qofP PUBLIC AFFAIRS August 8, 2011 In reply refer to: DK-7 Richard van Dijk Another Way BPA FOIA BPA-2011-01630-F Dear Mr. van Dijk: Thank you for your request...

  13. bpa-2011-01733-FOIA Correspondence

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

    30, 2011 In reply refer to: DK-7 Richard van Dijk Ex 6 FOIA BPA-2011-01733-F Dear Mr. van Dijk: Thank you for your request for records that you made to the Bonneville Power...

  14. BPA-2011-01782-FOIA Correspondence

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

    Oregon 97208-362 PUBLIC AFFAIRS August 31, 2011 In reply refer to: DK-7 Richard van Dijk FOIA BPA-2011-01782-F Dear Mr. van Dijk: Thank you for your request for records that...

  15. BPA-2013-00484-FOIA Response

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

    4, 2013 In reply refer to: DK-7 Richard van Dijk Another Way BPA PO Box 820152 Vancouver, WA 98682 FOIA BPA-2013-00484-F Dear Mr. van Dijk: Thank you for your request for records...

  16. Portland HQ Letterhead

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

    1, 2011 In reply refer to: DK-7 Richard van Dijk Another Way BPA Ex 6 FOIA BPA-2012-00236-F Dear Mr. van Dijk: Thank you for your request for records that you made to the...

  17. BPA-2010-01108-FOIA Correspondence

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

    4, 2010 In reply refer to: DK-7 Richard van Dijk Better Way for BPA 19521 NE 212 th Avenue Brush Prairie, WA 98606 RE: BPA-2010-01108-F Dear Mr. van Dijk: Thank you for your...

  18. BPA 2011-00359-FOIA Response

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

    4, 2011 In reply refer to: DK-7 Mr. Richard van Dijk Another Way BPA P.O. Box 820152 Vancouver, WA 98682 RE: FOIA BPA-2011-00359-F Dear Mr. van Dijk: This is a final response to...

  19. Electricity Advisory Committee Meeting Presentations March 2015...

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

    David Wade, EPB Chattanooga Craig Miller, NRECA Vickie VanZandt, VanZandt Electric ... (811.25 KB) Panel Presentation - Craig Miller, NRECA (948.63 KB) Panel ...

  20. Correlated Pc4-5 ULF waves, whistler-mode chorus, and pulsating...

    Office of Scientific and Technical Information (OSTI)

    and pulsating aurora observed by the Van Allen Probes and ground-based systems Citation ... and pulsating aurora observed by the Van Allen Probes and ground-based systems Theory and ...

  1. The global context of the 14 November 2012 storm event (Journal...

    Office of Scientific and Technical Information (OSTI)

    From 2 to 5 UT on 14 November 2012, the Van Allen Probes observed repeated particle flux ... field lines with similar occurrence patterns to those of the Van Allen Probe events. ...

  2. Source and seed populations for relativistic electrons: Their...

    Office of Scientific and Technical Information (OSTI)

    Strong enhancements of outer Van Allen belt electrons have been shown to have a clear ... orbit electron flux data and Van Allen Probes particle and fields data to study ...

  3. Spatial structure and temporal evolution of energetic particle...

    Office of Scientific and Technical Information (OSTI)

    Recent results by the Van Allen Probes mission showed that the occurrence of energetic ion ... storm (Dst -40 nT) on 14 July 2013. Van Allen Probe B, inside geosynchronous orbit, ...

  4. Fact #704: December 5, 2011 Fuel Consumption Standards for New...

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

    4: December 5, 2011 Fuel Consumption Standards for New Heavy Pickups and Vans Fact 704: December 5, 2011 Fuel Consumption Standards for New Heavy Pickups and Vans In September ...

  5. BPA-2012-00189-C Response

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

    4, 2012 In reply refer to: DK-7 Richard van Dijk Ex 6 FOIA Consult BPA-2012-00189-C Dear Mr. van Dijk: This is the final response to the request for documents you made through the...

  6. Curriculum Vitae

    Office of Scientific and Technical Information (OSTI)

    ... Owen, M. G. Schultz, D. Shindell, S. J. Smith, E. Stehfest, J. Van Aardenne, O. R. ... K. Riahi, S. J. Smith, D. P. van Vuuren, A. Conley, F. Vitt: Global and regional evolution ...

  7. OSTIblog Articles in the space technology Topic | OSTI, US Dept of Energy

    Office of Scientific and Technical Information (OSTI)

    Office of Scientific and Technical Information space technology Topic James Van Allen - Space Pioneer by Kathy Chambers 10 Jun, 2016 in james_van_allen_wcaption.jpg James Van Allen's space instrumentation innovations and his advocacy for Earth satellite planetary missions ensured his place among the early leaders of space exploration. After World War II, Van Allen begin his atmospheric research at the Johns Hopkins University Applied Physics Laboratory and Brookhaven National Laboratory. He

  8. HOPE Release 3 Pitch Angle Sneak Peak

    SciTech Connect (OSTI)

    Larsen, Brian Arthur; Skoug, Ruth M.

    2015-12-04

    This report describes how the HOPE instrument is used to measure subatomic particles in the Van Allen belts.

  9. Proper Orthogonal Decomposition of the Flow in a T-Junction (In: Advances

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

    Study - Propane Bakery Delivery Step Vans April 2016 1 Contents Background .......................................................................................................................................................................... 3 Motivation for Adopting Propane ................................................................................................................................... 3 Financial Benefits

  10. OSTI, US Dept of Energy Office of Scientific and Technical Information |

    Office of Scientific and Technical Information (OSTI)

    Speeding access to science information from DOE and Beyond James Van Allen - Space Pioneer by Kathy Chambers on Fri, June 10, 2016 james_van_allen_wcaption.jpg James Van Allen's space instrumentation innovations and his advocacy for Earth satellite planetary missions ensured his place among the early leaders of space exploration. After World War II, Van Allen begin his atmospheric research at the Johns Hopkins University Applied Physics Laboratory and Brookhaven National Laboratory. He went

  11. Curvature and ionization-induced reversible hydrogen storage in metalized hexagonal B{sub 36}

    SciTech Connect (OSTI)

    Liu, Chun-Sheng Wang, Xiangfu; Yan, Xiaohong; Ye, Xiao-Juan; Zeng, Zhi

    2014-11-21

    The synthesis of quasiplanar boron clusters (B{sub 36}) with a central hexagonal hole provides the first experimental evidence that a single-atomic-layer borophene with hexagonal vacancies is potentially viable [Z. Piazza, H. Hu, W. Li, Y. Zhao, J. Li, and L. S. Wang, Nat. Commun. 5, 3113 (2014)]. However, owing to the hexagonal holes, tunning the electronic and physical properties of B{sub 36} through chemical modifications is not fully understood. Based on (van der Waals corrected-) density functional theory, we show that Li adsorbed on B{sub 36} and B{sub 36}{sup ?} clusters can serve as reversible hydrogen storage media. The present results indicate that the curvature and ionization of substrates can enhance the bond strength of Li due to the energetically favorable B 2p-Li 2p orbitals hybridization. Both the polarization mechanism and the orbital hybridization between H-s orbitals and Li-2s2p orbitals contribute to the adsorption of H{sub 2} molecules and the resulting adsorption energy lies between the physisorbed and chemisorbed states. Interestingly, the number of H{sub 2} in the hydrogen storage medium can be measured by the appearance of the negative differential resistance behavior at different bias voltage regions. Furthermore, the cluster-assembled hydrogen storage materials constructed by metalized B{sub 36} clusters do not cause a decrease in the number of adsorbed hydrogen molecules per Li. The system reported here is favorable for the reversible hydrogen adsorption/desorption at ambient conditions.

  12. Exploring the Random Phase Approximately for materials chemistry and physics

    SciTech Connect (OSTI)

    Ruzsinsky, Adrienn

    2015-03-23

    This proposal focuses on improved accuracy for the delicate energy differences of interest in materials chemistry with the fully nonlocal random phase approximation (RPA) in a density functional context. Could RPA or RPA-like approaches become standard methods of first-principles electronic-structure calculation for atoms, molecules, solids, surfaces, and nano-structures? Direct RPA includes the full exact exchange energy and a nonlocal correlation energy from the occupied and unoccupied Kohn-Sham orbitals and orbital energies, with an approximate but universal description of long-range van der Waals attraction. RPA also improves upon simple pair-wise interaction potentials or vdW density functional theory. This improvement is essential to capture accurate energy differences in metals and different phases of semiconductors. The applications in this proposal are challenges for the simpler approximations of Kohn-Sham density functional theory, which are part of the current “standard model” for quantum chemistry and condensed matter physics. Within this project we already applied RPA on different structural phase transitions on semiconductors, metals and molecules. Although RPA predicts accurate structural parameters, RPA has proven not equally accurate in all kinds of structural phase transitions. Therefore a correction to RPA can be necessary in many cases. We are currently implementing and testing a nonempirical, spatially nonlocal, frequency-dependent model for the exchange-correlation kernel in the adiabatic-connection fluctuation-dissipation context. This kernel predicts a nearly-exact correlation energy for the electron gas of uniform density. If RPA or RPA-like approaches prove to be reliably accurate, then expected increases in computer power may make them standard in the electronic-structure calculations of the future.

  13. Computational study of Gleevec and G6G reveals molecular determinants of kinase inhibitor selectivity

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

    Lin, Yen -Lin; Meng, Yilin; Huang, Lei; Roux, Benoît

    2014-10-22

    Gleevec is a potent inhibitor of Abl tyrosine kinase but not of the highly homologous c-Src kinase. Because the ligand binds to an inactive form of the protein in which an Asp-Phe-Gly structural motif along the activation loop adopts a so-called DFG-out conformation, it was suggested that binding specificity was controlled by a “conformational selection” mechanism. In this context, the binding affinity displayed by the kinase inhibitor G6G poses an intriguing challenge. Although it possesses a chemical core very similar to that of Gleevec, G6G is a potent inhibitor of both Abl and c-Src kinases. Both inhibitors bind to themore » DFG-out conformation of the kinases, which seems to be in contradiction with the conformational selection mechanism. To address this issue and display the hidden thermodynamic contributions affecting the binding selectivity, molecular dynamics free energy simulations with explicit solvent molecules were carried out. Relative to Gleevec, G6G forms highly favorable van der Waals dispersive interactions upon binding to the kinases via its triazine functional group, which is considerably larger than the corresponding pyridine moiety in Gleevec. Upon binding of G6G to c-Src, these interactions offset the unfavorable free energy cost of the DFG-out conformation. When binding to Abl, however, G6G experiences an unfavorable free energy penalty due to steric clashes with the phosphate-binding loop, yielding an overall binding affinity that is similar to that of Gleevec. Such steric clashes are absent when G6G binds to c-Src, due to the extended conformation of the phosphate-binding loop.« less

  14. The quantum nature of the OH stretching mode in ice and water probed by neutron scattering experiments

    SciTech Connect (OSTI)

    Senesi, Roberto; Flammini, Davide; Kolesnikov, Alexander I; Murray, Eamonn D.; Galli, Giulia; Andreani, Carla

    2013-01-01

    The OH stretching vibrational spectrum of water was measured in a wide range of temperatures across the triple point, 269 K < T < 296 K, using Inelastic Neutron Scattering (INS). The hydrogen projected density of states and the proton mean kinetic energy, _OH, were determined for the first time within the framework of a harmonic description of the proton dynamics. We found that in the liquid the value of _OH is nearly constant as a function of T, indicating that quantum effects on the OH stretching frequency are weakly dependent on temperature. In the case of ice, ab initio electronic structure calculations, using non-local van der Waals functionals, provided _OH values in agreement with INS experiments. We also found that the ratio of the stretching (_OH) to the total (_exp) kinetic energy, obtained from the present measurements, increases in going from ice, where hydrogen bonding is the strongest, to the liquid at ambient conditions and then to the vapour phase, where hydrogen bonding is the weakest. The same ratio was also derived from the combination of previous deep inelastic neutron scattering data, which does not rely upon the harmonic approximation, and the present measurements. We found that the ratio of stretching to the total kinetic energy shows a minimum in the metastable liquid phase. This finding suggests that the strength of intermolecular interactions increases in the supercooled phase, with respect to that in ice, contrary to the accepted view that supercooled water exhibits weaker hydrogen bonding than ice.

  15. Sub-discretized surface model with application to contact mechanics in multi-body simulation

    SciTech Connect (OSTI)

    Johnson, S; Williams, J

    2008-02-28

    The mechanics of contact between rough and imperfectly spherical adhesive powder grains are often complicated by a variety of factors, including several which vary over sub-grain length scales. These include several traction factors that vary spatially over the surface of the individual grains, including high energy electron and acceptor sites (electrostatic), hydrophobic and hydrophilic sites (electrostatic and capillary), surface energy (general adhesion), geometry (van der Waals and mechanical), and elasto-plastic deformation (mechanical). For mechanical deformation and reaction, coupled motions, such as twisting with bending and sliding, as well as surface roughness add an asymmetry to the contact force which invalidates assumptions for popular models of contact, such as the Hertzian and its derivatives, for the non-adhesive case, and the JKR and DMT models for adhesive contacts. Though several contact laws have been offered to ameliorate these drawbacks, they are often constrained to particular loading paths (most often normal loading) and are relatively complicated for computational implementation. This paper offers a simple and general computational method for augmenting contact law predictions in multi-body simulations through characterization of the contact surfaces using a hierarchically-defined surface sub-discretization. For the case of adhesive contact between powder grains in low stress regimes, this technique can allow a variety of existing contact laws to be resolved across scales, allowing for moments and torques about the contact area as well as normal and tangential tractions to be resolved. This is especially useful for multi-body simulation applications where the modeler desires statistical distributions and calibration for parameters in contact laws commonly used for resolving near-surface contact mechanics. The approach is verified against analytical results for the case of rough, elastic spheres.

  16. Low-Frequency Interlayer Raman Modes to Probe Interface of Twisted Bilayer MoS 2

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

    Huang, Shengxi; Liang, Liangbo; Ling, Xi; Puretzky, Alexander A.; Geohegan, David B.; Sumpter, Bobby G.; Kong, Jing; Meunier, Vincent; Dresselhaus, Mildred S.

    2016-02-21

    A variety of van der Waals homo- and hetero- structures assembled by stamping monolayers together present optoelectronic properties suitable for diverse applications. Understanding the details of the interlayer stacking and resulting coupling is crucial for tuning these properties. Twisted bilayer transition metal dichalcogenides offer a great platform for developing a precise understanding of the structure/property relationship. Here, we study the low-frequency interlayer shear and breathing Raman modes (<50 cm-1) in twisted bilayer MoS2 by Raman spectroscopy and first-principles modeling. Twisting introduces both rotational and translational shifts and significantly alters the interlayer stacking and coupling, leading to notable frequency and intensitymore » changes of low-frequency modes. The frequency variation can be up to 8 cm-1 and the intensity can vary by a factor of ~5 for twisting near 0 and 60 , where the stacking is a mixture of multiple high-symmetry stacking patterns and is thus especially sensitive to twisting. Moreover, for twisting angles between 20 and 40 , the interlayer coupling is nearly constant since the stacking results in mismatched lattices over the entire sample. It follows that the Raman signature is relatively uniform. Interestingly, unlike the breathing mode, the shear mode is extremely sensitive to twisting: it disappears between 20 and 40 as its frequency drops to almost zero due to the stacking-induced mismatch. Note that for some samples, multiple breathing mode peaks appear, indicating non-uniform coupling across the interface. In contrast to the low-frequency interlayer modes, high-frequency intralayer Raman modes are much less sensitive to interlayer stacking and coupling, showing negligible changes upon twisting. Our research demonstrates the effectiveness of low-frequency Raman modes for probing the interfacial coupling and environment of twisted bilayer MoS2, and potentially other two-dimensional materials and

  17. Formation, characterization and dynamics of onion like carbon structures from nanodiamonds using reactive force-fields for electrical energy storage

    SciTech Connect (OSTI)

    Ganesh, Panchapakesan; Kent, Paul R; Mochalin, Vadym N

    2011-01-01

    We simulate the experimentally observed graphitization of nanodiamonds into multi-shell onion-like carbon nanostructures, also called carbon onions, at different temperatures, using reactive force fields. The simulations include long-range Coulomb and van der Waals interactions. Our results suggest that long-range interactions play a crucial role in the phase-stability and the graphitization process. Graphitization is both enthalpically and entropically driven and can hence be controlled with temperature. The outer layers of the nanodiamond have a lower kinetic barrier toward graphitization irrespective of the size of the nanodiamond and graphitize within a few-hundred picoseconds, with a large volume increase. The inner core of the nanodiamonds displays a large size-dependent kinetic barrier, and graphitizes much more slowly with abrupt jumps in the internal energy. It eventually graphitizes by releasing pressure and expands once the outer shells have graphitized. The degree of transformation at a particular temperature is thereby determined by a delicate balance between the thermal energy, long-range interactions, and the entropic/enthalpic free energy gained by graphitization. Upon full graphitization, a multi-shell carbon nanostructure appears, with a shell-shell spacing of about {approx}3.4 {angstrom} for all sizes. The shells are highly defective with predominantly five- and seven-membered rings to curve space. Larger nanodiamonds with a diameter of 4 nm can graphitize into spiral structures with a large ({approx}29-atom carbon ring) pore opening on the outermost shell. Such a large one-way channel is most attractive for a controlled insertion of molecules/ions such as Li ions, water, or ionic liquids, for increased electrochemical capacitor or battery electrode applications.

  18. Formation, characterization, and dynamics of onion-like carbon structures for electrical energy storage from nanodiamonds using reactive force fields

    SciTech Connect (OSTI)

    Ganesh, P.; Kent, P. R. C.; Mochalin, V.

    2011-10-01

    We simulate the experimentally observed graphitization of nanodiamonds into multi-shell onion-like carbonnanostructures, also called carbon onions, at different temperatures, using reactive force fields. The simulations include long-range Coulomb and van der Waals interactions. Our results suggest that long-range interactions play a crucial role in the phase-stability and the graphitization process. Graphitization is both enthalpically and entropically driven and can hence be controlled with temperature. The outer layers of the nanodiamond have a lower kinetic barrier toward graphitization irrespective of the size of the nanodiamond and graphitize within a few-hundred picoseconds, with a large volume increase. The inner core of the nanodiamonds displays a large size-dependent kinetic barrier, and graphitizes much more slowly with abrupt jumps in the internal energy. It eventually graphitizes by releasing pressure and expands once the outer shells have graphitized. The degree of transformation at a particular temperature is thereby determined by a delicate balance between the thermal energy, long-range interactions, and the entropic/enthalpic free energy gained by graphitization. Upon full graphitization, a multi-shell carbonnanostructure appears, with a shell-shell spacing of about ~3.4 for all sizes. The shells are highly defective with predominantly five- and seven-membered rings to curve space. Larger nanodiamonds with a diameter of 4 nm can graphitize into spiral structures with a large (~29-atom carbon ring) pore opening on the outermost shell. Such a large one-way channel is most attractive for a controlled insertion of molecules/ions such as Li ions, water, or ionic liquids, for increased electrochemical capacitor or battery electrode applications.

  19. Predicting the influence of long-range molecular interactions on macroscopic-scale diffusion by homogenization of the Smoluchowski equation

    SciTech Connect (OSTI)

    Kekenes-Huskey, P. M.; Gillette, A. K.; McCammon, J. A.; Department of Chemistry, Howard Hughes Medical Institute, University of California San Diego, La Jolla, California 92093-0636

    2014-05-07

    The macroscopic diffusion constant for a charged diffuser is in part dependent on (1) the volume excluded by solute obstacles and (2) long-range interactions between those obstacles and the diffuser. Increasing excluded volume reduces transport of the diffuser, while long-range interactions can either increase or decrease diffusivity, depending on the nature of the potential. We previously demonstrated [P. M. Kekenes-Huskey et al., Biophys. J. 105, 2130 (2013)] using homogenization theory that the configuration of molecular-scale obstacles can both hinder diffusion and induce diffusional anisotropy for small ions. As the density of molecular obstacles increases, van der Waals (vdW) and electrostatic interactions between obstacle and a diffuser become significant and can strongly influence the latter's diffusivity, which was neglected in our original model. Here, we extend this methodology to include a fixed (time-independent) potential of mean force, through homogenization of the Smoluchowski equation. We consider the diffusion of ions in crowded, hydrophilic environments at physiological ionic strengths and find that electrostatic and vdW interactions can enhance or depress effective diffusion rates for attractive or repulsive forces, respectively. Additionally, we show that the observed diffusion rate may be reduced independent of non-specific electrostatic and vdW interactions by treating obstacles that exhibit specific binding interactions as buffers that absorb free diffusers. Finally, we demonstrate that effective diffusion rates are sensitive to distribution of surface charge on a globular protein, Troponin C, suggesting that the use of molecular structures with atomistic-scale resolution can account for electrostatic influences on substrate transport. This approach offers new insight into the influence of molecular-scale, long-range interactions on transport of charged species, particularly for diffusion-influenced signaling events occurring in crowded

  20. Stability of numerous novel potassium chlorides at high pressure

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

    Zhang, Weiwei; Oganov, Artem R.; Lobanov, Sergey S.; Stavrou, Elissaios; Goncharov, Alexander F.; Zhu, Qiang

    2016-05-23

    K-Cl is a simple system displaying all four main types of bonding, as it contains (i) metallic potassium, (ii) elemental chlorine made of covalently bonded Cl2 molecules held together by van der Waals forces, and (iii) an archetypal ionic compound KCl. The charge balance rule, assigning classical charges of “+1” to K and “–1” to Cl, predicts that no compounds other than KCl are possible. However, our quantum-mechanical variable-composition evolutionary simulations predict an extremely complex phase diagram, with new thermodynamically stable compounds K3Cl, K2Cl, K3Cl2, K4Cl3, K5Cl4, K3Cl5, KCl3 and KCl7. Of particular interest are 2D-metallic homologs Kn+1Cln, the presencemore » of positively charged Cl atoms in KCl7, and the predicted stability of KCl3 already at nearly ambient pressures at zero Kelvin. We have synthesized cubic Pm3¯n -KCl3 at 40–70 GPa and trigonal P3¯cl -KCl3 at 20–40 GPa in a laser-heated diamond anvil cell (DAC) at temperature exceeding 2000 K from KCl and Cl2. These phases were identified using in situ synchrotron X-ray diffraction and Raman spectroscopy. Lastly, upon unloading to 10 GPa, P3¯cl -KCl3 transforms to a yet unknown structure before final decomposition to KCl and Cl2 at near-ambient conditions.« less

  1. Particle Restabilization in Silica/PEG/Ethanol Suspensions: How Strongly do Polymers Need To Adsorb To Stabilize Against Aggregation?

    SciTech Connect (OSTI)

    Kim, So Youn; Zukoski, Charles F.

    2014-09-24

    We study the effects of increasing the concentration of a low molecular weight polyethylene glycol on the stability of 44 nm diameter silica nanoparticles suspended in ethanol. Polymer concentration, c{sub p}, is increased from zero to that characterizing the polymer melt. Particle stability is accessed through measurement of the particle second-virial coefficient, B{sub -2}, performed by light scattering and ultrasmall angle X-ray scattering (USAXS). The results show that at low polymer concentration, c{sub p} < 3 wt %, B{sub -2} values are positive, indicating repulsive interactions between particles. B{sub -2} decreases at intermediate concentrations (3 wt % < c{sub p} < 50 wt %), and particles aggregates are formed. At high concentrations (50 wt % < c{sub p}) B{sub -2} increases and stabilizes at a value expected for hard spheres with a diameter near 44 nm, indicating the particles are thermodynamically stable. At intermediate polymer concentrations, rates of aggregation are determined by measuring time-dependent changes in the suspension turbidity, revealing that aggregation is slowed by the necessity of the particles diffusing over a repulsive barrier in the pair potential. The magnitude of the barrier passes through a minimum at c{sub p} {approx} 12 wt % where it has a value of {approx}12kT. These results are understood in terms of a reduction of electrostatic repulsion and van der Waals attractions with increasing c{sub p}. Depletion attractions are found to play a minor role in particle stability. A model is presented suggesting displacement of weakly adsorbed polymer leads to slow aggregation at intermediate concentration, and we conclude that a general model of depletion restabilization may involve increased strength of polymer adsorption with increasing polymer concentration.

  2. Molecular Electronic Level Alignment at Weakly Coupled Organic Film/Metal Interfaces

    SciTech Connect (OSTI)

    Zhao, Jin; Feng, Min; Dougherty, Daniel B.; Sun, Hao; Petek, Hrvoje

    2014-10-28

    Electronic level alignment at interfaces of molecular materials with inorganic semiconductors and metals controls many interfacial phenomena. How the intrinsic properties of the interacting systems define the electronic structure of their interface remains one of the most important problems in molecular electronics and nanotechnology that can be solved through a combination of surface science experimental techniques and theoretical modeling. In this article, we address this fundamental problem through experimental and computational studies of molecular electronic level alignment of thin films of C6F6 on noble metal surfaces. The unoccupied electronic structure of C6F6 is characterized with single molecule resolution using low-temperature scanning tunneling microscopy-based constant-current distance-voltage spectroscopy. The experiments are performed on several noble metal surfaces with different work functions and distinct surface-normal projected band structures. In parallel, the electronic structures of the quantum wells (QWs) formed by the lowest unoccupied molecular orbital state of the C6F6 monolayer and multilayer films and their alignment with respect to the vacuum level of the metallic substrates are calculated by solving the Schrdinger equation for a semiempirical one-dimensional (1D) potential of the combined system using input from density functional theory. Our analysis shows that the level alignment for C6F6 molecules bound through weak van der Waals interactions to noble metal surfaces is primarily defined by the image potential of metal, the electron affinity of the molecule, and the molecule surface distance. We expect the same factors to determine the interfacial electronic structure for a broad range of molecule/metal interfaces.

  3. Solvation Free Energies of Alanine Peptides: The Effect of Flexibility

    SciTech Connect (OSTI)

    Kokubo, Hironori; Harris, Robert C.; Asthagiri, Dilip; Pettitt, Bernard M.

    2013-12-03

    The electrostatic (?Gel), cavity-formation (?Gvdw), and total (?G) solvation free energies for 10 alanine peptides ranging in length (n) from 1 to 10 monomers were calculated. The free energies were computed both with xed, extended conformations of the peptides and again for some of the peptides without constraints. The solvation free energies, ?Gel, ?Gvdw, and ?G, were found to be linear in n, with the slopes of the best-fit lines being gamma_el, gamma_vdw, and gamma, respectively. Both gamma_el and gamma were negative for fixed and flexible peptides, and gamma_vdw was negative for fixed peptides. That gamma_vdw was negative was surprising, as experimental data on alkanes, theoretical models, and MD computations on small molecules and model systems generally suggest that gamma_vdw should be positive. A negative gamma_vdw seemingly contradicts the notion that ?Gvdw drives the initial collapse of the protein when it folds by favoring conformations with small surface areas, but when we computed ?Gvdw for the flexible peptides, thereby allowing the peptides to assume natural ensembles of more compact conformations, gamma-vdw was positive. Because most proteins do not assume extended conformations, a ?Gvdw that increases with increasing surface area may be typical for globular proteins. An alternative hypothesis is that the collapse is driven by intramolecular interactions. We show that the intramolecular van der Waal's interaction energy is more favorable for the flexible than for the extended peptides, seemingly favoring this hypothesis, but the large fluctuations in this energy may make attributing the collapse of the peptide to this intramolecular energy difficult.

  4. Doping against the native propensity of MoS₂: Degenerate hole doping by cation substitution

    SciTech Connect (OSTI)

    Suh, Joonki; Park, Tae-Eon; Lin, Der-Yuh; Fu, Deyi; Park, Joonsuk; Jung, Hee Joon; Chen, Yabin; Ko, Changhyun; Jang, Chaun; Sun, Yinghui; Sinclair, Robert; Chang, Joonyeon; Tongay, Sefaattin; Wu, Junqiao

    2014-12-10

    Layered transition metal dichalcogenides (TMDs) draw much attention as the key semiconducting material for two-dimensional electrical, optoelectronic, and spintronic devices. For most of these applications, both n- and p-type materials are needed to form junctions and support bipolar carrier conduction. However, typically only one type of doping is stable for a particular TMD. For example, molybdenum disulfide (MoS₂) is natively an n-type presumably due to omnipresent electron-donating sulfur vacancies, and stable/controllable p-type doping has not been achieved. The lack of p-type doping hampers the development of charge-splitting p–n junctions of MoS₂, as well as limits carrier conduction to spin-degenerate conduction bands instead of the more interesting, spin-polarized valence bands. Traditionally, extrinsic p-type doping in TMDs has been approached with surface adsorption or intercalation of electron-accepting molecules. However, practically stable doping requires substitution of host atoms with dopants where the doping is secured by covalent bonding. In this work, we demonstrate stable p-type conduction in MoS₂ by substitutional niobium (Nb) doping, leading to a degenerate hole density of ~3 × 10¹⁹ cm⁻³. Structural and X-ray techniques reveal that the Nb atoms are indeed substitutionally incorporated into MoS₂ by replacing the Mo cations in the host lattice. van der Waals p–n homojunctions based on vertically stacked MoS₂ layers are fabricated, which enable gate-tunable current rectification. A wide range of microelectronic, optoelectronic, and spintronic devices can be envisioned from the demonstrated substitutional bipolar doping of MoS₂. From the miscibility of dopants with the host, it is also expected that the synthesis technique demonstrated here can be generally extended to other TMDs for doping against their native unipolar propensity.

  5. A reactive force field study of Li/C systems for electrical energy storage

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

    Raju, Muralikrishna; Ganesh, P.; Kent, Paul R. C.; van Duin, Adri C.T.

    2015-04-02

    Graphitic carbon is still the most ubiquitously used anode material in Li-ion batteries. In spite of its ubiquity, there are few theoretical studies that fully capture the energetics and kinetics of Li in graphite and related nanostructures at experimentally relevant length, time-scales, and Li-ion concentrations. In this paper, we describe the development and application of a ReaxFF reactive force field to describe Li interactions in perfect and defective carbon-based materials using atomistic simulations. We develop force field parameters for Li–C systems using van der Waals-corrected density functional theory (DFT). Grand canonical Monte Carlo simulations of Li intercalation in perfect graphitemore » with this new force field not only give a voltage profile in good agreement with known experimental and DFT results but also capture the in-plane Li ordering and interlayer separations for stage I and II compounds. In defective graphite, the ratio of Li/C (i.e., the capacitance increases and voltage shifts) both in proportion to the concentration of vacancy defects and metallic lithium is observed to explain the lithium plating seen in recent experiments. We also demonstrate the robustness of the force field by simulating model carbon nanostructures (i.e., both 0D and 1D structures) that can be potentially used as battery electrode materials. Whereas a 0D defective onion-like carbon facilitates fast charging/discharging rates by surface Li adsorption, a 1D defect-free carbon nanorod requires a critical density of Li for intercalation to occur at the edges. Our force field approach opens the opportunity for studying energetics and kinetics of perfect and defective Li/C structures containing thousands of atoms as a function of intercalation. As a result, this is a key step toward modeling of realistic carbon materials for energy applications.« less

  6. Molecular dynamics study of the effect of alkyl chain length on melting points of [CnMIM][PF6] ionic liquids

    SciTech Connect (OSTI)

    Zhang, Y; Maginn, EJ

    2014-01-01

    Based on molecular dynamics simulations, the melting points T-m of a series of 1-alkyl-3-methylimidazolium hexafluorophosphate ionic liquids [CnMIM][PF6] with n = 2, 4, 10, 12, and 14 were studied using the free energy-based pseudosupercritical path (PSCP) method. The experimental trend that the Tm decreases with increasing alkyl chain length for ILs with short alkyl chains and increases for the ones with long alkyl chains was correctly captured. Further analysis revealed that the different trends are the results of the balance between fusion enthalpy and fusion entropy. For the ILs with short alkyl chains (ethyl and butyl groups), fusion entropy plays the dominant role so that [C4MIM][PF6], which has a larger fusion entropy due to its higher liquid phase entropy has the lower melting temperature. As for the ILs with long alkyl chains, due to the enhanced van der Waals interactions brought about by the long non-polar alkyl chains, enthalpy becomes the deciding factor and the melting points increase when the alkyl chain goes from C10 to C14. While the melting points for [C2MIM][PF6] and [C4MIM][PF6] were quantitatively predicted and the trends for the long chain ILs were captured correctly, the absolute melting points for [C10MIM][PF6], [C12MIM][PF6] and [C14MIM][PF6] were systematically overestimated in the simulations. Three possible reasons for the overestimation were studied but all ruled out. Further simulation or experimental studies are needed to explain the difference.

  7. A Thermally Stable Form of Bacterial Cocaine Esterase: A Potential Therapeutic Agent for Treatment of Cocaine Abuse

    SciTech Connect (OSTI)

    Brim, Remy L.; Nance, Mark R.; Youngstrom, Daniel W.; Narasimhan, Diwahar; Zhan, Chang-Guo; Tesmer, John J.G.; Sunahara, Roger K.; Woods, James H.

    2010-09-03

    Rhodococcal cocaine esterase (CocE) is an attractive potential treatment for both cocaine overdose and cocaine addiction. CocE directly degrades cocaine into inactive products, whereas traditional small-molecule approaches require blockade of the inhibitory action of cocaine on a diverse array of monoamine transporters and ion channels. The usefulness of wild-type (wt) cocaine esterase is hampered by its inactivation at 37 C. Herein, we characterize the most thermostable form of this enzyme to date, CocE-L169K/G173Q. In vitro kinetic analyses reveal that CocE-L169K/G173Q displays a half-life of 2.9 days at 37 C, which represents a 340-fold improvement over wt and is 15-fold greater than previously reported mutants. Crystallographic analyses of CocE-L169K/G173Q, determined at 1.6-{angstrom} resolution, suggest that stabilization involves enhanced domain-domain interactions involving van der Waals interactions and hydrogen bonding. In vivo rodent studies reveal that intravenous pretreatment with CocE-L169K/G173Q in mice provides protection from cocaine-induced lethality for longer time periods before cocaine administration than wt CocE. Furthermore, intravenous administration (pretreatment) of CocE-L169K/G173Q prevents self-administration of cocaine in a time-dependent manner. Termination of the in vivo effects of CoCE seems to be dependent on, but not proportional to, its clearance from plasma as its half-life is approximately 2.3 h and similar to that of wt CocE (2.2 h). Taken together these data suggest that CocE-L169K/G173Q possesses many of the properties of a biological therapeutic for treating cocaine abuse but requires additional development to improve its serum half-life.

  8. The individual and collective effects of exact exchange and dispersion interactions on the ab initio structure of liquid water

    SciTech Connect (OSTI)

    DiStasio, Robert A.; Santra, Biswajit; Li, Zhaofeng; Wu, Xifan; Car, Roberto

    2014-08-28

    In this work, we report the results of a series of density functional theory (DFT) based ab initio molecular dynamics (AIMD) simulations of ambient liquid water using a hierarchy of exchange-correlation (XC) functionals to investigate the individual and collective effects of exact exchange (Exx), via the PBE0 hybrid functional, non-local van der Waals/dispersion (vdW) interactions, via a fully self-consistent density-dependent dispersion correction, and an approximate treatment of nuclear quantum effects, via a 30 K increase in the simulation temperature, on the microscopic structure of liquid water. Based on these AIMD simulations, we found that the collective inclusion of Exx and vdW as resulting from a large-scale AIMD simulation of (H{sub 2}O){sub 128} significantly softens the structure of ambient liquid water and yields an oxygen-oxygen structure factor, S{sub OO}(Q), and corresponding oxygen-oxygen radial distribution function, g{sub OO}(r), that are now in quantitative agreement with the best available experimental data. This level of agreement between simulation and experiment demonstrated herein originates from an increase in the relative population of water molecules in the interstitial region between the first and second coordination shells, a collective reorganization in the liquid phase which is facilitated by a weakening of the hydrogen bond strength by the use of a hybrid XC functional, coupled with a relative stabilization of the resultant disordered liquid water configurations by the inclusion of non-local vdW/dispersion interactions. This increasingly more accurate description of the underlying hydrogen bond network in liquid water also yields higher-order correlation functions, such as the oxygen-oxygen-oxygen triplet angular distribution, P{sub OOO}(θ), and therefore the degree of local tetrahedrality, as well as electrostatic properties, such as the effective molecular dipole moment, that are in much better agreement with experiment.

  9. New XDM-corrected potential energy surfaces for ArNO(X{sup 2}?): A comparison with CCSD(T) calculations and experiments

    SciTech Connect (OSTI)

    Warehime, Michael; Johnson, Erin R.; K?os, Jacek

    2015-01-14

    We report new potential energy surfaces for the ground state ArNO(X{sup 2}?) van der Waals system calculated using the unrestricted Hartree-Fock (UHF) method with the addition of the Becke-Roussel correlation functional and exchange-hole dipole moment dispersion correction (XDM). We compare UHFBR-XDM surfaces and those previously reported by Alexander from coupled cluster CCSD(T) calculations [J. Chem. Phys. 111, 7426 (1999)]. The bound states of ArNO have been investigated with these new UHFBR-XDM surfaces, including relative energy-level spacing, adiabatic bender states and wave functions, and spectroscopic data. These results have been found to be in good agreement with calculations based on the CCSD(T) PESs. These new PESs are used to investigate the inelastic scattering of NO(X) by Ar. Full close-coupling integral cross sections at collision energies of 442 cm{sup ?1}, 1774 cm{sup ?1} and differential cross sections at collision energy of 530 cm{sup ?1} were determined for transitions out of the lowest NO(X) rotational level (j = ? = 1/2,f). These cross sections are in good agreement with those calculated with CCSD(T) and accordingly in good agreement with the most recent initial and final state resolved experimental data. The UHFBR-XDM scheme yields high-quality potential surfaces with computational cost comparable to the Hartree-Fock method and our results may serve as a benchmark for application of this scheme to collisions between larger molecules.

  10. Adsorption of Supercritical CO2 in Aeroglass Studied by Small--Angle Neutron Scattering and Neutron Transmission Techniques

    SciTech Connect (OSTI)

    Melnichenko, Yuri B [ORNL; Wignall, George D [ORNL; Cole, David R [ORNL; Frielinghaus, H. [Forschungszentrum Julich, Julich, Germany

    2006-01-01

    Small-angle neutron scattering (SANS) has been used to study the adsorption behavior of supercritical carbon dioxide (CO{sub 2}) in porous Vycor glass and silica aerogels. Measurements were performed along two isotherms (T = 35 and 80 C) as a function of pressure (P) ranging from atmospheric up to 25 MPa, which corresponds to the bulk fluid densities ranging from {rho}CO{sub 2} - 0 to 0.9 g/cm{sup 3}. The intensity of scattering from CO{sub 2}-saturated Vycor porous glass can be described by a two-phase model which suggests that CO{sub 2} does not adsorb on the pore walls and fills the pore space uniformly. In CO{sub 2}-saturated aerogels an adsorbed phase is formed with a density substantially higher that of the bulk fluid, and neutron transmission data were used to monitor the excess adsorption at different pressures. The results indicate that adsorption of CO{sub 2} is significantly stronger in aerogels than in activated carbons, zeolites, and xerogels due to the extremely high porosity and optimum pore size of these materials. SANS data revealed the existence of a compressed adsorbed phase with the average density - 1.07 g/cm{sup 3}, close to the density corresponding to closely packed van der Waals volume of CO{sub 2}. A three-phase model [W. L. Wu, Polymer 23, 1907 (1982)] was used to estimate the volume fraction {phi}{sub 3} of the adsorbed phase as a function of the fluid density, and gave {phi}{sub 3} - 0.78 in the maximum adsorption regime around {rho}CO{sub 2} - 0.374 g/cm{sup 3}. The results presented in this work demonstrate the utility of SANS combined with the transmission measurements to study the adsorption of supercritical fluids in porous materials.

  11. A reactive force field study of Li/C systems for electrical energy storage

    SciTech Connect (OSTI)

    Raju, Muralikrishna; Ganesh, P.; Kent, Paul R. C.; van Duin, Adri C.T.

    2015-04-02

    Graphitic carbon is still the most ubiquitously used anode material in Li-ion batteries. In spite of its ubiquity, there are few theoretical studies that fully capture the energetics and kinetics of Li in graphite and related nanostructures at experimentally relevant length, time-scales, and Li-ion concentrations. In this paper, we describe the development and application of a ReaxFF reactive force field to describe Li interactions in perfect and defective carbon-based materials using atomistic simulations. We develop force field parameters for Li–C systems using van der Waals-corrected density functional theory (DFT). Grand canonical Monte Carlo simulations of Li intercalation in perfect graphite with this new force field not only give a voltage profile in good agreement with known experimental and DFT results but also capture the in-plane Li ordering and interlayer separations for stage I and II compounds. In defective graphite, the ratio of Li/C (i.e., the capacitance increases and voltage shifts) both in proportion to the concentration of vacancy defects and metallic lithium is observed to explain the lithium plating seen in recent experiments. We also demonstrate the robustness of the force field by simulating model carbon nanostructures (i.e., both 0D and 1D structures) that can be potentially used as battery electrode materials. Whereas a 0D defective onion-like carbon facilitates fast charging/discharging rates by surface Li adsorption, a 1D defect-free carbon nanorod requires a critical density of Li for intercalation to occur at the edges. Our force field approach opens the opportunity for studying energetics and kinetics of perfect and defective Li/C structures containing thousands of atoms as a function of intercalation. As a result, this is a key step toward modeling of realistic carbon materials for energy applications.

  12. Electricity Advisory Committee Meeting Presentations March 2016...

    Energy Savers [EERE]

    Technical Advisor, and Carl Imhoff, PNNL Panel: Valuation and Integration of DERs - Paul ... Parks and Carl Imhoff.pdf PDF icon DER Panel Introduction - Paul Centolella.pdf PDF ...

  13. Advancements in Distributed Generation Issues: Interconnection, Modeling, and Tariffs

    SciTech Connect (OSTI)

    Thomas, H.; Kroposki, B.; Basso, T.; Treanton, B. G.

    2007-01-01

    The California Energy Commission is cost-sharing research with the Department of Energy through the National Renewable Energy Laboratory to address distributed energy resources (DER) topics. These efforts include developing interconnection and power management technologies, modeling the impacts of interconnecting DER with an area electric power system, and evaluating possible modifications to rate policies and tariffs. As a result, a DER interconnection device has been developed and tested. A workshop reviewed the status and issues of advanced power electronic devices. Software simulations used validated models of distribution circuits that incorporated DER, and tests and measurements of actual circuits with and without DER systems are being conducted to validate these models. Current policies affecting DER were reviewed and rate making policies to support deployment of DER through public utility rates and policies were identified. These advancements are expected to support the continued and expanded use of DER systems.

  14. Browse Societies by Language -- E-print Network Societies by...

    Office of Scientific and Technical Information (OSTI)

    ... Kernenergie nergie Nuclaire Suisse -- Schweizer Licht Gesellschaft Swiss Lighting Society (SLG) -- Schweizerische Akademie der Naturwissenschaften Acadmie suisse ...

  15. Before the House Science and Technology Subcommittee on Energy and Environment

    Office of Energy Efficiency and Renewable Energy (EERE)

    Subject: FutureGen Near-Zero Emission Power Plant By: Victor Der, Acting Assistant Secretary, Office of Fossil Energy

  16. Hanford Sludge Simulant Selection for Soil Mechanics Property Measurement

    SciTech Connect (OSTI)

    Wells, Beric E.; Russell, Renee L.; Mahoney, Lenna A.; Brown, Garrett N.; Rinehart, Donald E.; Buchmiller, William C.; Golovich, Elizabeth C.; Crum, Jarrod V.

    2010-03-23

    The current System Plan for the Hanford Tank Farms uses relaxed buoyant displacement gas release event (BDGRE) controls for deep sludge (i.e., high level waste [HLW]) tanks, which allows the tank farms to use more storage space, i.e., increase the sediment depth, in some of the double-shell tanks (DSTs). The relaxed BDGRE controls are based on preliminary analysis of a gas release model from van Kessel and van Kesteren. Application of the van Kessel and van Kesteren model requires parametric information for the sediment, including the lateral earth pressure at rest and shear modulus. No lateral earth pressure at rest and shear modulus in situ measurements for Hanford sludge are currently available. The two chemical sludge simulants will be used in follow-on work to experimentally measure the van Kessel and van Kesteren model parameters, lateral earth pressure at rest, and shear modulus.

  17. Assessment of Distributed Generation Potential in JapaneseBuildings

    SciTech Connect (OSTI)

    Zhou, Nan; Marnay, Chris; Firestone, Ryan; Gao, Weijun; Nishida,Masaru

    2005-05-25

    To meet growing energy demands, energy efficiency, renewable energy, and on-site generation coupled with effective utilization of exhaust heat will all be required. Additional benefit can be achieved by integrating these distributed technologies into distributed energy resource (DER) systems (or microgrids). This research investigates a method of choosing economically optimal DER, expanding on prior studies at the Berkeley Lab using the DER design optimization program, the Distributed Energy Resources Customer Adoption Model (DER-CAM). DER-CAM finds the optimal combination of installed equipment from available DER technologies, given prevailing utility tariffs, site electrical and thermal loads, and a menu of available equipment. It provides a global optimization, albeit idealized, that shows how the site energy loads can be served at minimum cost by selection and operation of on-site generation, heat recovery, and cooling. Five prototype Japanese commercial buildings are examined and DER-CAM applied to select the economically optimal DER system for each. The five building types are office, hospital, hotel, retail, and sports facility. Based on the optimization results, energy and emission reductions are evaluated. Furthermore, a Japan-U.S. comparison study of policy, technology, and utility tariffs relevant to DER installation is presented. Significant decreases in fuel consumption, carbon emissions, and energy costs were seen in the DER-CAM results. Savings were most noticeable in the sports facility (a very favourable CHP site), followed by the hospital, hotel, and office building.

  18. Observations and simulations improve space weather models

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

    Observations improve space weather models Observations and simulations improve space weather models Researchers used data from the Van Allen Probes to improve a three-dimensional model created by Los Alamos scientists called DREAM3D. June 25, 2014 NASA's Van Allen Probes sample the Earth's magnetosphere. NASA's Van Allen Probes sample the Earth's magnetosphere. The work demonstrated that DREAM3D accurately simulated the behavior of a complex and dynamic event in the radiation belt that was

  19. Observations and simulations improve space weather models

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

    Observations improve space weather models Observations and simulations improve space weather models Researchers used data from the Van Allen Probes to improve a three-dimensional model created by Los Alamos scientists called DREAM3D. June 25, 2014 NASA's Van Allen Probes sample the Earth's magnetosphere. NASA's Van Allen Probes sample the Earth's magnetosphere. The work demonstrated that DREAM3D accurately simulated the behavior of a complex and dynamic event in the radiation belt that was

  20. Earth's Magnetosphere

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

    Mysterious electron stash found hidden among Van Allen belts March 1, 2013 Instruments detect never-before-seen phenomenon in Earth's Magnetosphere LOS ALAMOS, N.M., March 1, 2013-U.S. researchers, including a trio from Los Alamos National Laboratory, have witnessed the mysterious appearance of a relatively long-lived zone of high-energy electrons stored between Earth's Van Allen radiation belts. The surprising findings, discovered by NASA's Van Allen Probes (formerly known as the Radiation Belt