Sample records for elastic potential energy

  1. Polarization potential for elastic scattering of {sup 6,7}Li + {sup 28}Si at near-barrier energies

    SciTech Connect

    Pakou, Athena [Department of Physics, The University of Ioannina, GR-45110 Ioannina (Greece)

    2008-12-15

    The polarization potential for the elastic scattering of {sup 6,7}Li + {sup 28}Si at near barrier energies has been investigated in the context of an optical model framework. The effect on the elastic scattering was found to be strong, energy dependent, and compatible with the transfer channel.

  2. Elastic alpha scattering experiments and the alpha-nucleus optical potential at low energies

    SciTech Connect

    Mohr, P., E-mail: mohr@atomki.mta.hu [Institute of Nuclear Research (ATOMKI), H-4001 Debrecen (Hungary); Diakonie-Klinikum, D-74523 Schwäbisch Hall (Germany)] [Germany; Kiss, G.G.; Fülöp, Zs. [Institute of Nuclear Research (ATOMKI), H-4001 Debrecen (Hungary)] [Institute of Nuclear Research (ATOMKI), H-4001 Debrecen (Hungary); Galaviz, D. [Centro de Física Nuclear, University of Lisbon, P-1649-003 Lisbon (Portugal)] [Centro de Física Nuclear, University of Lisbon, P-1649-003 Lisbon (Portugal); Gyürky, Gy.; Somorjai, E. [Institute of Nuclear Research (ATOMKI), H-4001 Debrecen (Hungary)] [Institute of Nuclear Research (ATOMKI), H-4001 Debrecen (Hungary)

    2013-11-15

    High precision angular distribution data of (?,?) elastic scattering are presented for the nuclei {sup 89}Y, {sup 92}Mo, {sup 106,110,116}Cd, {sup 112,124}Sn, and {sup 144}Sm at energies around the Coulomb barrier. Such data with small experimental uncertainties over the full angular range (20–170°) are the indispensable prerequisite for the extraction of local optical potentials and for the determination of the total reaction cross section ?{sub reac}. A systematic fitting procedure was applied to the experimental scattering data presented to obtain comprehensive local potential parameter sets that are composed of a real folding potential and an imaginary potential of Woods–Saxon surface type. The potential parameters obtained were used in turn to construct a new systematic ?-nucleus potential with very few parameters. Although this new potential cannot reproduce the angular distributions with the same small deviations as the local potential, the new potential is able to predict the total reaction cross sections for all cases under study.

  3. Free energies for coarse-grained proteins by integrating multibody statistical contact potentials with entropies from elastic network models

    Microsoft Academic Search

    Michael T. Zimmermann; Sumudu P. Leelananda; Pawel Gniewek; Yaping Feng; Robert L. Jernigan; Andrzej Kloczkowski

    2011-01-01

    We propose a novel method of calculation of free energy for coarse grained models of proteins by combining our newly developed\\u000a multibody potentials with entropies computed from elastic network models of proteins. Multi-body potentials have been of much\\u000a interest recently because they take into account three dimensional interactions related to residue packing and capture the\\u000a cooperativity of these interactions in

  4. Notepad-like triboelectric generator for efficiently harvesting low-velocity motion energy by interconversion between kinetic energy and elastic potential energy.

    PubMed

    Liu, Guanlin; Leng, Qiang; Lian, Jiawei; Guo, Hengyu; Yi, Xi; Hu, Chenguo

    2015-01-21

    Great attention has been paid to nanogenerators that harvest energy from ambient environments lately. In order to give considerable output current, most nanogenerators require high-velocity motion that in most cases can hardly be provided in our daily life. Here we report a notepad-like triboelectric generator (NTEG), which uses simple notepad-like structure to generate elastic deformation so as to turn a low-velocity kinetic energy into high-velocity kinetic energy through the conversion of elastic potential energy. Therefore, the NTEG can achieve high current output under low-velocity motion, which completely distinguishes it from tribogenerators previously reported. The factors that may affect the output performance are explored, including the number of slices, active length of slice, press speed, and vertical displacement. In addition, the working mechanism is systematically studied, indicating that the efficiency of the generator can be greatly enhanced by interconversion between kinetic energy and elastic potential energy. The short-circuit current, the open-circuit voltage, and power density are 205 ?A and 470 V and 9.86 W/m(2), respectively, which is powerful enough to light up hundreds of light-emitting diodes (LEDs) and charge a commercial capacitor. Besides, NTEGs have been successfully applied to a self-powered door monitor. PMID:25564956

  5. Close-coupling calculations of low-energy inelastic and elastic processes in 4He collisions with H2: A comparative study of two potential energy surfaces.

    PubMed

    Lee, Teck-Ghee; Rochow, C; Martin, R; Clark, T K; Forrey, R C; Balakrishnan, N; Stancil, P C; Schultz, D R; Dalgarno, A; Ferland, Gary J

    2005-01-01

    The two most recently published potential energy surfaces (PESs) for the HeH2 complex, the so-called MR (Muchnick and Russek) and BMP (Boothroyd, Martin, and Peterson) surfaces, are quantitatively evaluated and compared through the investigation of atom-diatom collision processes. The BMP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the PES compared to that of the MR surface. We found significant differences in inelastic rovibrational cross sections computed on the two surfaces for processes dominated by large changes in target rotational angular momentum. In particular, the H2(nu=1,j=0) total quenching cross section computed using the BMP potential was found to be a factor of 1000 larger than that obtained with the MR surface. A lesser discrepancy persists over a large range of energies from the ultracold to thermal and occurs for other low-lying initial rovibrational levels. The MR surface was used in previous calculations of the H2(nu=1,j=0) quenching rate coefficient and gave results in close agreement with the experimental data of Audibert et al. which were obtained for temperatures between 50 and 300 K. Examination of the rovibronic coupling matrix elements, which are obtained following a Legendre expansion of the PES, suggests that the magnitude of the anisotropy of the BMP potential is too large in the interaction region. However, cross sections for elastic and pure rotational processes obtained from the two PESs differ typically by less than a factor of 2. The small differences may be ascribed to the long-range and anharmonic components of the PESs. Exceptions occur for (nu=10,j=0) and (nu=11,j=1) where significant enhancements have been found for the low-energy quenching and elastic cross sections due to zero-energy resonances in the BMP PES which are not present in the MR potential. PMID:15638586

  6. Potentials for the ?- 40,44,48Ca elastic scattering

    NASA Astrophysics Data System (ADS)

    Abdullah, M. N. A.; Idris, A. B.; Tariq, A. S. B.; Islam, M. S.; Das, S. K.; Uddin, M. A.; Mondal, A. S.; Basak, A. K.; Reichstein, I.; Sen Gupta, H. M.; Malik, F. B.

    2005-10-01

    The differential cross sections for the elastic scattering of ? particles by 40,44,48Ca, over a wide range of incident energies, have been analyzed using a deep as well as shallow non-monotonic optical potential and compared with those using a squared Woods-Saxon (SWS) potential. The shallow non-monotonic potential exhibits a volume integral for the real part, characteristic of a molecular potential. The parameters of the SWS potential have also been obtained for ?- 48Ca scattering. The parameters of the shallow non-monotonic potential calculated from the energy-density-formalism provide a satisfactory description of the elastic scattering data. The non-monotonic potentials, both deep and shallow, are found to yield consistently a lower value of the radius parameter of the real potential for 48Ca than that for 40Ca, in conformity with the observed magnitudes of the root-mean-square radii for the two nuclei. Both the potentials indicate that the semi-magic 44Ca behaves differently from the doubly-magic 40,48Ca, in agreement with the findings from the folding potentials. The dispersion effect arising from the causality principle has been investigated for the shallow non-monotonic ?- 40Ca potential and is found to play a rather minor role in describing the elastic scattering data.

  7. The elastic energy of damaged rocks

    NASA Astrophysics Data System (ADS)

    Hamiel, Y.; Lyakhovsky, V.; Ben-Zion, Y.

    2009-12-01

    Crustal rocks are typically treated as linear elastic material with constant elastic moduli. This assumption is appropriate for rock with relatively low damage, associated with low concentration of cracks and flaws, and under relatively small strains. However, laboratory and field data indicate that rocks subjected to sufficiently high loads exhibit clear deviations from linear behavior. In general, nonlinear stress-strain relationships of rocks can be approximated by including higher-order terms of the strain tensor in the elastic energy expression (e.g., the Murnaghan model). Such models are successful for calculating rock deformation under high confining pressure. However, values of the third (higher order) Murnaghan moduli estimated from acoustic experiments are one to two orders of magnitude above the expected values of the same moduli estimated from the stress-strain relations in quasi-static rock-mechanics experiments. The Murnaghan model also fails to reproduce an abrupt change in the elastic moduli when deformation changes from compression to tension. Such behavior was observed in laboratory experiments with rocks, concrete, and composite brittle material samples. Bi-linear elastic models with abrupt change of the moduli under stress reversal were suggested based on acoustic experiments ("clapping" nonlinearity) and in continuum damage mechanics (unilateral damage model). Here we present a theoretical basis for general second-order nonlinear expression of the elastic potential. We then show that a simplified version of the general nonlinear model is consistent with bi-linear elastic behavior and accounts for non-linearity even under small strains. We apply the simplified nonlinear model to various laboratory observations, including quasi-static modeling of rocks and composite material with different effective moduli under tension and compression; rock dilation under shear; stress- and damage-induced seismic wave anisotropy observed during cycling load of granite samples; and acoustic experiments analyzing shift of the resonance frequency in rock samples. Comparison between analytical and numerical calculations and experimental results demonstrate that the suggested expression for the elastic potential for rocks accounts for both quasi-static damage accumulation and nonlinear dynamic effects.

  8. Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Section Data for the $^{12}$C+$^{208}$Pb System at Near-Coulomb-Barrier Energies by using a Folding Potential

    E-print Network

    W. Y. So; T. Udagawa; S. W. Hong; B. T. Kim

    2008-01-15

    Simultaneous $\\chi^{2}$ analyses are performed for elastic scattering and fusion cross section data for the $^{12}$C+$^{208}$Pb system at near-Coulomb-barrier energies by using the extended optical model approach in which the polarization potential is decomposed into direct reaction (DR) and fusion parts. Use is made of the double folding potential as a bare potential. It is found that the experimental elastic scattering and fusion data are well reproduced without introducing any normalization factor for the double folding potential and also that both DR and fusion parts of the polarization potential determined from the $\\chi^{2}$ analyses satisfy separately the dispersion relation. Furthermore, it is shown that the imaginary parts of both DR and fusion potentials at the strong absorption radius change very rapidly, which results in a typical threshold anomaly in the total imaginary potential as observed with tightly bound projectiles such as $\\alpha$-particle and $^{16}$O.

  9. An excitation potential imaging condition for elastic reverse time migration

    NASA Astrophysics Data System (ADS)

    Gu, Bingluo; Liu, Youshan; Li, Zhiyuan; Ma, Xiaona; Liang, Guanghe

    2014-09-01

    Elastic reverse time migration (ERTM) has been demonstrated to be more accurate than scalar RTM. However, low efficiency (large storage and heavy calculated amount) and strong artifacts caused by the crosstalk between different wave modes are the two primary barriers to the application of the ERTM during the processing of real data. The scalar (P) and vector (S) potentials of the elastic wavefield and the arrival times corresponding to the first energy extremum of the wavefield are saved at each grid point during the forward modeling of the source wavefield. The angle-dependent reflection coefficient images are subsequently obtained by dividing the scalar and vector potentials of the backward extrapolated receiver wavefield by the saved scalar and vector potentials at the grid points that satisfy the image time at each time step, respectively. The proposed imaging condition does not need to store the snapshots of the source wavefield, while it can considerably improve the computational efficiency and decrease the amount of storage and Input/Output manipulation (compared with the cross-correlation imaging condition) in addition to suppressing the crosstalk between compressive and shear wave modes. Compared with the excitation time imaging condition, the proposed imaging condition reduces the energy loss caused by the opposite polarity of the horizontal component at opposite sides of the source in stacked images. Numerical tests with synthetic data of the Sigsbee2a model have demonstrated that this imaging condition is a cost-effective and practical imaging condition for use in prestack ERTM.

  10. Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Section Data for the 7Li+208Pb System at Near-Coulomb-Barrier Energies using the Folding Potential

    E-print Network

    W. Y. So; T. Udagawa; K. S. Kim; S. W. Hong; B. T. Kim

    2007-06-05

    Simultaneous $\\chi^{2}$ analyses previously made for elastic scattering and fusion cross section data for the $^{6}$Li+$^{208}$Pb system is extended to the $^{7}$Li+$^{208}$Pb system at near-Coulomb-barrier energies based on the extended optical model approach, in which the polarization potential is decomposed into direct reaction (DR) and fusion parts. Use is made of the double folding potential as a bare potential. It is found that the experimental elastic scattering and fusion data are well reproduced without introducing any normalization factor for the double folding potential and that both the DR and fusion parts of the polarization potential determined from the $\\chi^{2}$ analyses satisfy separately the dispersion relation. Further, we find that the real part of the fusion portion of the polarization potential is attractive while that of the DR part is repulsive except at energies far below the Coulomb barrier energy. A comparison is made of the present results with those obtained from the Continuum Discretized Coupled Channel (CDCC) calculations and a previous study based on the conventional optical model with a double folding potential. We also compare the present results for the $^7$Li+$^{208}$Pb system with the analysis previously made for the $^{6}$Li+$^{208}$Pb system.

  11. Close-coupling calculations of low-energy inelastic and elastic processes in $^4$He collisions with H$_2$: A comparative study of two potential energy surfaces

    E-print Network

    T. G. Lee; C. Rochow; R. Martin; T. K. Clark; R. C. Forrey; N. Balakrishnan; P. C. Stancil; D. R. Schultz; A. Dalgarno; G. J. Ferland

    2004-12-09

    The two most recently published potential energy surfaces (PESs) for the HeH$_2$ complex, the so-called MR (Muchnick and Russek) and BMP (Boothroyd, Martin, and Peterson) surfaces, are quantitatively evaluated and compared through the investigation of atom-diatom collision processes. The BMP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the PES compared to that of the MR surface. We found significant differences in inelastic rovibrational cross sections computed on the two surfaces for processes dominated by large changes in target rotational angular momentum. In particular, the H$_2$($\

  12. Calculations of $^{6}$He+p elastic scattering cross sections using folding approach and high-energy approximation for the optical potential

    E-print Network

    K. V. Lukyanov; V. K. Lukyanov; E. V. Zemlyanaya; A. N. Antonov; M. K. Gaidarov

    2007-08-27

    Calculations of microscopic optical potentials (OP's) (their real and imaginary parts) are performed to analyze the $^6$He+p elastic scattering data at a few tens of MeV/nucleon (MeV/N). The OP's and the cross sections are calculated using three model densities of $^6$He. Effects of the regularization of the NN forces and their dependence on nuclear density are investigated. Also, the role of the spin-orbit terms and of the non-linearity in the calculations of the OP's, as well as effects of their renormalization are studied. The sensitivity of the cross sections to the nuclear densities was tested and one of them that gives a better agreement with the data was chosen.

  13. Velocity-dependent optical potential for neutron elastic scattering from 1 p -shell nuclei

    NASA Astrophysics Data System (ADS)

    Ghabar, I. N.; Jaghoub, M. I.

    2015-06-01

    Background: The conventional optical model is quite successful in describing the nucleon elastic scattering data from medium and heavy nuclei. However, its success in describing the light 1 p -shell nuclei is somewhat limited. The velocity-dependent optical potential resulted in a significant improvement in describing the elastic angular distributions for light nuclei in the low energy region. Purpose: To extend the formalism of the velocity-dependent potential to higher energies, and to assess its importance in describing neutron elastic scattering data from light 1 p -shell nuclei at high energies. Method: We fit the angular distribution data for neutron elastic scattering from 12C and 16O using (i) the velocity-dependent optical potential and (ii) the conventional optical potential. The results of the two models are then compared. At low energies, we compare our angular distribution fits with the fits of other works that exist in the literature. Furthermore, the total integrated cross sections in addition to the analyzing power are calculated using the velocity-dependent optical potential and compared to the experimental data. Results: The velocity-dependent potential resulted in significant improvements in describing the angular distributions particularly in the large-angle scattering region and for certain energy ranges. This model is important where the experimental data show structural effects from nuclear surface deformations, which are important in light nuclei. Furthermore, the calculated total elastic cross sections and analyzing power are in good agreement with the experimental data. Conclusions: The velocity-dependent potential gives rise to surface-peaked real terms in the optical model. Such terms account, at least partly, for the structural effects seen in the angular distribution data. The energy range over which the surface terms are needed is found to depend on the target nucleus. Other works that have introduced real surface terms in the optical potential are discussed.

  14. Second Order Elastic Constants and Some Thermoelastic Properties of Alkali Halides Using WOODCOCK Potential

    NASA Astrophysics Data System (ADS)

    Yazar, Harun Reþýt; Aðan, Sedat; Çolakoðlu, Kemal

    2001-07-01

    Second Order Elastic Constants (S.O.E.C) of NaCl-type crystals have been calculated using the Woodcock potential. Short-range repulsive interactions have been included up to second-nearest neighbors. This potential form represents the composite form of the inverse power dependence and exponential dependence of the repulsive energy on interionic distance. Some thermoelastic and thermodynamic properties such as Anderson-Grüneisen parameters d T, and d S, Volume thermal expansion coefficient b and Grüneisen gama g G have been calculated in terms of calculated values of S.O.E.C and Third Order Elastic Constant ( T.O.E.C).

  15. Transient accumulation of elastic energy in proton translocating ATP synthase

    E-print Network

    Steinhoff, Heinz-Jürgen

    Hypothesis Transient accumulation of elastic energy in proton translocating ATP synthase Dmitry A,18^20]. We analyzed the transient elastic storage of energy derived from four proton-translocation steps between FH and FI (see Fig. 1) gives a clue to how the elastic energy storage might function. The proton

  16. Probing the potential and reaction coupling effects of {sup 6,7}Li+{sup 28}Si at sub- and near-barrier energies with elastic backscattering

    SciTech Connect

    Zerva, K.; Pakou, A.; Patronis, N.; Aslanoglou, X.; Nicolis, N. G. [Department of Physics and HINP, The University of Ioannina, GR-45110 Ioannina (Greece); Rusek, K. [Heavy Ion Laboratory, University of Warsaw, Warsaw (Poland); Department of Nuclear Reactions, Andrzej Soltan Institute for Nuclear Studies, Warsaw (Poland); Alamanos, N. [CEA-Saclay DSM/IRFU/DIR, F-91191 Gif-sur-Yvette (France); Filipescu, D.; Glodariu, T. [''Horia Hulubei'' National Institute of Physics and Nuclear Engineering (Romania); Keeley, N. [Department of Nuclear Reactions, Andrzej Soltan Institute for Nuclear Studies, Warsaw (Poland); Kokkoris, M. [National Technical University of Athens (Greece); La Commara, M. [Dipartimento di Scienze Fisiche and INFN Sezione di Napoli, I-80125, Napoli (Italy); Lagoyannis, A. [National Research Center Demokritos (Greece); Mazzocco, M. [Dipartimento di Fisica, INFN, I-35131 Padova (Italy); Pierroutsakou, D.; Romoli, M. [INFN Sezione di Napoli, I-80125, Napoli (Italy)

    2010-10-15

    The excitation functions for {sup 7}Li+{sup 28}Si quasielastic scattering at 150 deg. and 170 deg. have been measured at sub- and near-barrier energies (0.6 to 1.3 V{sub B}) and the corresponding barrier distributions derived. The results were analyzed within the framework of the optical model using a procedure similar to one used on previous results for {sup 6}Li+{sup 28}Si employing double-folded potentials calculated using the BDM3Y1 effective interaction. The variation of the surface strength of the optical potential as a function of incident energy was compared for the two systems {sup 6}Li+{sup 28}Si and {sup 7}Li+{sup 28}Si, the barrier distributions being used to help better define the potential at the lowest energies. The barrier distributions were also analyzed with continuum-discretized coupled-channel (CDCC) and coupled reaction channel (CRC) calculations as a means of investigating the influence of breakup and transfer reactions on these quantities for these light, weakly bound projectiles.

  17. Microscopic optical potential analyses of carbon-carbon elastic scattering

    NASA Technical Reports Server (NTRS)

    Bidasaria, H. B.; Townsend, L. W.

    1984-01-01

    Utilizing eikonal phase shifts determined from a microscopic double-folding optical potential, marked improvement in the agreement between theory and experiment, for elastic carbon-carbon scattering between 200 and 300 MeV, is obtained when only those values for the nucleon-nucleon slope parameter, appropriate for diffractive scattering, are used. The appropriateness of the perturbative eikonal expansion is discussed by comparison with recent results, obtained for the same potentials, using a more exact complex Wentzell-Kramers-Brillouin (WKB) formalism.

  18. Elastic Incoherent Neutron Scattering, operating by varying instrumental energy resolution, Principles, Simulations and Experiments of the Resolution Elastic Neutron

    E-print Network

    Doster, Wolfgang

    Elastic Incoherent Neutron Scattering, operating by varying instrumental energy resolution, Principles, Simulations and Experiments of the Resolution Elastic Neutron Scattering (RENS) by Magazu a different name "RENS" (resolution dependent elastic neutron scattering) [1-5]. Our ERS papers, first

  19. Elastic energy of polyhedral bilayer vesicles

    E-print Network

    Christoph A. Haselwandter; Rob Phillips

    2011-06-10

    In recent experiments [M. Dubois, B. Dem\\'e, T. Gulik-Krzywicki, J.-C. Dedieu, C. Vautrin, S. D\\'esert, E. Perez, and T. Zemb, Nature (London) Vol. 411, 672 (2001)] the spontaneous formation of hollow bilayer vesicles with polyhedral symmetry has been observed. On the basis of the experimental phenomenology it was suggested [M. Dubois, V. Lizunov, A. Meister, T. Gulik-Krzywicki, J. M. Verbavatz, E. Perez, J. Zimmerberg, and T. Zemb, Proc. Natl. Acad. Sci. U.S.A. Vol. 101, 15082 (2004)] that the mechanism for the formation of bilayer polyhedra is minimization of elastic bending energy. Motivated by these experiments, we study the elastic bending energy of polyhedral bilayer vesicles. In agreement with experiments, and provided that excess amphiphiles exhibiting spontaneous curvature are present in sufficient quantity, we find that polyhedral bilayer vesicles can indeed be energetically favorable compared to spherical bilayer vesicles. Consistent with experimental observations we also find that the bending energy associated with the vertices of bilayer polyhedra can be locally reduced through the formation of pores. However, the stabilization of polyhedral bilayer vesicles over spherical bilayer vesicles relies crucially on molecular segregation of excess amphiphiles along the ridges rather than the vertices of bilayer polyhedra. Furthermore, our analysis implies that, contrary to what has been suggested on the basis of experiments, the icosahedron does not minimize elastic bending energy among arbitrary polyhedral shapes and sizes. Instead, we find that, for large polyhedron sizes, the snub dodecahedron and the snub cube both have lower total bending energies than the icosahedron.

  20. Phenomenological study of relativistic optical model potentials in proton elastic scattering

    NASA Astrophysics Data System (ADS)

    Kobos, A. M.; Cooper, E. D.; Johansson, J. I.; Sherif, H. S.

    1985-12-01

    Elastic proton scattering at energies between 160 and 800 MeV from 4He, 16O, 40Ca, 80Zr and 208Pb has been studied within the phenomenological Dirac optical model. We find potential parameters which give good fits to the experimental data comprising differential cross section, analysing power and, in two cases, spin rotation function measurements. Ambiguities exist in the potential parameters for the imaginary vector, and particularly the imaginary scalar components. Two types of parameter sets are found: some sets have "shallow" imaginary potentials, others are characterized by "deep" ones. At higher energies some of the ambiguities might be resolved should the spin rotation function Q be measured and fitted. The real potentials are well determined and behave regularly with energy. The ratio of the volume integrals of the real vector and scalar potentials decreases linearly with energy and is almost independent of the mass number.

  1. Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities

    NASA Astrophysics Data System (ADS)

    Baylin-Stern, Adam C.

    This paper demonstrates how an U.S. application of CIMS, a technologically explicit and behaviourally realistic energy-economy simulation model which includes macro-economic feedbacks, can be used to derive estimates of elasticity of substitution (ESUB) and autonomous energy efficiency index (AEEI) parameters. The ability of economies to reduce greenhouse gas emissions depends on the potential for households and industry to decrease overall energy usage, and move from higher to lower emissions fuels. Energy economists commonly refer to ESUB estimates to understand the degree of responsiveness of various sectors of an economy, and use estimates to inform computable general equilibrium models used to study climate policies. Using CIMS, I have generated a set of future, 'pseudo-data' based on a series of simulations in which I vary energy and capital input prices over a wide range. I then used this data set to estimate the parameters for transcendental logarithmic production functions using regression techniques. From the production function parameter estimates, I calculated an array of elasticity of substitution values between input pairs. Additionally, this paper demonstrates how CIMS can be used to calculate price-independent changes in energy-efficiency in the form of the AEEI, by comparing energy consumption between technologically frozen and 'business as usual' simulations. The paper concludes with some ideas for model and methodological improvement, and how these might figure into future work in the estimation of ESUBs from CIMS. Keywords: Elasticity of substitution; hybrid energy-economy model; translog; autonomous energy efficiency index; rebound effect; fuel switching.

  2. Finite-Difference Time-Domain Numerical Analysis of Elastic Wave Fields Using both Elastic and Velocity Potential Variables

    NASA Astrophysics Data System (ADS)

    Sato, Masahiro

    2006-05-01

    The use of both elastic variables and velocity potentials is proposed for the analysis of elastic wave fields in isotropic solids by finite-difference time-domain (FDTD) methods. The term ‘elastic variables’ refers to stresses and particle velocities. Velocity potentials can be directly derived using the same leap-frog finite-difference scheme as in the FDTD method. In some situations, for example, where an absorbing boundary is present, it is more straightforward to calculate using velocity potentials. This approach also provides an easy way to handle of complex elastic wave phenomena. On the other hand, many other types of boundary conditions are often expressed in terms of elastic variables. In these situations, it is more convenient to use elastic variables for calculation. Some examples are introduced here to illustrate the efficiency of the proposed technique. First, the method was used for the case of an absorbing boundary. In the model, almost all analysis was carried out using values of stress and particle velocity, but velocity potentials were applied near the absorbing boundary on the truncated interface. Second, an interface between elastic variables and velocity potentials, namely a stress-velocity/potentials interface, was constructed around a scattering object. External to the interface, stresses and particle velocities were used for calculation, and potential variables were applied inside the interface. In a third example, calculations were made over almost the entire analytical region using potential values, but in the neighborhood of the free boundary, elastic variables were used. All the examples above were analyzed numerically using the FDTD method, and the results confirmed the usefulness of the method.

  3. Low-energy elastic differential scattering of He/++/ by He.

    NASA Technical Reports Server (NTRS)

    Lam, S. K.; Doverspike, L. D.; Champion, R. L.

    1973-01-01

    Experimental results are developed for the relative elastic differential scattering of He(++) by He for collision energies in the range 4 equal to or less than E equal to or less than 75 eV. In the analysis of the data, semiclassical considerations are utilized, assuming that the dynamics of the scattering is governed solely by the B and E states of He2(++). It is shown that existing ab initio calculations for the intermolecular potentials predict differential cross sections which are not in particularly good agreement with the experimental data.

  4. Interaction potential for indium phosphide: a molecular dynamics and first-principles study of the elastic constants, generalized stacking fault and surface energies

    Microsoft Academic Search

    Paulo Sergio Branicio; José Pedro Rino; Chee Kwan Gan; Hélio Tsuzuki

    2009-01-01

    Indium phosphide is investigated using molecular dynamics (MD) simulations and density-functional theory calculations. MD simulations use a proposed effective interaction potential for InP fitted to a selected experimental dataset of properties. The potential consists of two- and three-body terms that represent atomic-size effects, charge-charge, charge-dipole and dipole-dipole interactions as well as covalent bond bending and stretching. Predictions are made for

  5. Interaction potential for indium phosphide: a molecular dynamics and first-principles study of the elastic constants, generalized stacking fault and surface energies

    Microsoft Academic Search

    Paulo Sergio Branicio; José Pedro Rino; Chee Kwan Gan; Hélio Tsuzuki

    2009-01-01

    Indium phosphide is investigated using molecular dynamics (MD) simulations and density-functional theory calculations. MD simulations use a proposed effective interaction potential for InP fitted to a selected experimental dataset of properties. The potential consists of two- and three-body terms that represent atomic-size effects, charge–charge, charge–dipole and dipole–dipole interactions as well as covalent bond bending and stretching. Predictions are made for

  6. Elastic Energy Transfer in Turbulence of Dilute Polymer Solution

    NASA Astrophysics Data System (ADS)

    Xi, Heng-Dong; Bodenschatz, Eberhard; Xu, Haitao

    2012-11-01

    We present an experimental study of the energy transfer in the bulk of a turbulent flow with small amount long-chain polymer additives. By varying the Reynolds numbers R?, Wissenberg number Wi and polymer concentration ?. We test quantitively the elastic theory proposed by de Gennes and Tabor (Europhys. Lett., 1986; Physica A, 1986). The rate of energy transfer by polymer elasticity as inferred from the theory is consistent with that measured from the second order Eulerian structure functions. The unknown parameter n in the theory, which represents the flow topology of the stretching field, is found to be nearly 1. Based on energy transfer rate balance, We propose an elastic length scale, r?, which describes the effect of polymer elasticity on turbulence energy cascade and captures the scale dependence of the elastic energy transfer rate. We are grateful to the Max Planck Society, the Alexander von Humboldt Foundation and the Deutsche Forschungsgemeinschaft for their support.

  7. Calculations of $^{8}$He+p Elastic Cross Sections Using Microscopic Optical Potential

    E-print Network

    V. K. Lukyanov; E. V. Zemlyanaya; K. V. Lukyanov; D. N. Kadrev; A. N. Antonov; M. K. Gaidarov; S. E. Massen

    2009-08-07

    An approach to calculate microscopic optical potential (OP) with the real part obtained by a folding procedure and with the imaginary part inherent in the high-energy approximation (HEA) is applied to study the $^8$He+p elastic scattering data at energies of tens of MeV/nucleon (MeV/N). The neutron and proton density distributions obtained in different models for $^{8}$He are utilized in the calculations of the differential cross sections. The role of the spin-orbit potential is studied. Comparison of the calculations with the available experimental data on the elastic scattering differential cross sections at beam energies of 15.7, 26.25, 32, 66 and 73 MeV/N is performed. The problem of the ambiguities of the depths of each component of the optical potential is considered by means of the imposed physical criterion related to the known behavior of the volume integrals as functions of the incident energy. It is shown also that the role of the surface absorption is rather important, in particular for the lowest incident energies (e.g., 15.7 and 26.25 MeV/nucleon).

  8. Study of $^{6}$He+$^{12}$C Elastic Scattering Using a Microscopic Optical Potential

    E-print Network

    V. K. Lukyanov; D. N. Kadrev; E. V. Zemlyanaya; A. N. Antonov; K. V. Lukyanov; M. K. Gaidarov

    2010-07-23

    The $^6$He+$^{12}$C elastic scattering data at beam energies of 3, 38.3 and 41.6 MeV/nucleon are studied utilizing the microscopic optical potentials obtained by a double-folding procedure and also by using those inherent in the high-energy approximation. The calculated optical potentials are based on the neutron and proton density distributions of colliding nuclei established in an appropriate model for $^6$He and obtained from the electron scattering form factors for $^{12}$C. The depths of the real and imaginary parts of the microscopic optical potentials are considered as fitting parameters. At low energy the volume optical potentials reproduce sufficiently well the experimental data. At higher energies, generally, additional surface terms having form of a derivative of the imaginary part of the microscopic optical potential are needed. The problem of ambiguity of adjusted optical potentials is resolved requiring the respective volume integrals to obey the determined dependence on the collision energy. Estimations of the Pauli blocking effects on the optical potentials and cross sections are also given and discussed. Conclusions on the role of the aforesaid effects and on the mechanism of the considered processes are made.

  9. Energy in elastic fiber embedded in elastic matrix containing incident SH wave

    NASA Technical Reports Server (NTRS)

    Williams, James H., Jr.; Nagem, Raymond J.

    1989-01-01

    A single elastic fiber embedded in an infinite elastic matrix is considered. An incident plane SH wave is assumed in the infinite matrix, and an expression is derived for the total energy in the fiber due to the incident SH wave. A nondimensional form of the fiber energy is plotted as a function of the nondimensional wavenumber of the SH wave. It is shown that the fiber energy attains maximum values at specific values of the wavenumber of the incident wave. The results obtained here are interpreted in the context of phenomena observed in acousto-ultrasonic experiments on fiber reinforced composite materials.

  10. Differential elastic scattering of He* (21S) by Ar, Kr and Xe: Repulsive rainbows and optical potentials

    Microsoft Academic Search

    D. W. Martin; R. W. Gregor; R. M. Jordan; P. E. Siska

    1978-01-01

    Elastic scattering angular distributions of He* (21S) with Ar, Kr, and Xe measured in crossed atomic beams at collision energies from 0.4–2.8 kcal\\/mole are analyzed using a physically motivated optical potential model. The resulting potentials show some features expected on the basis of the analogous Li–rare gas potentials: monotonically increasing van der Waals well depths &egr; in the sequence Ar,

  11. Differential elastic scattering of He* (21S) by Ar, Kr and Xe: Repulsive rainbows and optical potentials

    Microsoft Academic Search

    D. W. Martin; R. W. Gregor; R. M. Jordan; P. E. Siska

    1978-01-01

    Elastic scattering angular distributions of He* (2¹S) with Ar, Kr, and Xe measured in crossed atomic beams at collision energies from 0.4--2.8 kcal\\/mole are analyzed using a physically motivated optical potential model. The resulting potentials show some features expected on the basis of the analogous Li--rare gas potentials: monotonically increasing van der Waals well depths epsilon in the sequence Ar,

  12. Elastic energy of proteins and the stages of protein folding

    E-print Network

    Lei, Jinzhi

    2010-01-01

    We propose a universal elastic energy for proteins, which depends only on the radius of gyration $R_{g}$ and the residue number $N$. It is constructed using physical arguments based on the hydrophobic effect and hydrogen bonding. Adjustable parameters are fitted to data from the computer simulation of the folding of a set of proteins using the CSAW (conditioned self-avoiding walk) model. The elastic energy gives rise to scaling relations of the form $R_{g}\\sim N^{\

  13. Normal-distortion-mode approach to liquid crystal elastic energy

    Microsoft Academic Search

    V. Schmidt

    1990-01-01

    It is shown that Frank's saddle'' distortion contribution to the nematic liquid-crystal distortional elastic energy is required, in addition to the splay, twist, and bend energies retained in more recent treatments. Normal distortion modes'' for these four distortions are described. Measurement methods and their interpretations are discussed for the corresponding four elastic constants {ital k}ââ (splay), {ital k}ââ (twist), {ital

  14. Solar energy potential

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The potential of solar energy as a national resource is discussed. Research and development programs for the development of eleven concepts are described to show the proposed funding for each year over a fifteen year period. The estimated energy contributions by period for each of the solar concepts are analyzed. The estimated impact of the solar concepts to the year 2020 are tabulated.

  15. Effects of the Inverse Square Potential on Nucleon-Nucleon Elastic Scattering in the Bethe-Salpeter Equation

    E-print Network

    Susumu Kinpara

    2015-03-25

    Bethe-Salpeter equation is applied to nucleon-nucleon elastic scattering at the intermediate energy. The differential cross section and the polarization are calculated in terms of the phase shift analysis method using the two-body potential derived from the Bethe-Salpeter equation. The lowest-order Born approximation for the K-matrix is corrected by including the inverse square part of the potential.

  16. The elastic energy of sharply bent nicked DNA

    NASA Astrophysics Data System (ADS)

    Qu, Hao; Tseng, Chiao-Yu; Wang, Yong; Levine, Alex J.; Zocchi, Giovanni

    2010-04-01

    We obtain measurements of the elastic energy of short (18-30 bp) molecules of ds DNA constrained into a sharply bent conformation, using a thermodynamic method with the DNA in solution. We consider the case where there is one nick in the ds DNA, and find that the system develops a kink at a critical torque ?c?27 pN×nm. In this regime the elastic energy is linear in the end-to-end distance (EED). For smaller torques the DNA is smoothly bent and described by the worm-like-chain energy, which is also approximately linear in the EED, but with a different slope. Thus we access both the high and low elastic energy regimes, and the transition between the two.

  17. On using many-particle interatomic potentials to compute elastic properties of graphene and diamond

    Microsoft Academic Search

    I. E. Berinskii; A. M. Krivtsov

    2010-01-01

    The elastic properties of diatomic crystals are considered. An approach is proposed that permits calculating the elastic characteristics\\u000a of crystals by using the interatomic interaction parameters specified as many-particle potentials, i.e., potentials that take\\u000a into account the effect of the environment on the diatomic interaction. The many-particle interaction is given in the general\\u000a form obtained in the framework of linear

  18. Quasi-elastic nuclear scattering at high energies

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.

    1992-01-01

    The quasi-elastic scattering of two nuclei is considered in the high-energy optical model. Energy loss and momentum transfer spectra for projectile ions are evaluated in terms of an inelastic multiple-scattering series corresponding to multiple knockout of target nucleons. The leading-order correction to the coherent projectile approximation is evaluated. Calculations are compared with experiments.

  19. Interaction potential for silicon carbide: A molecular dynamics study of elastic constants and vibrational density of states for crystalline

    E-print Network

    Southern California, University of

    Interaction potential for silicon carbide: A molecular dynamics study of elastic constants dynamics method, the interaction potential is used to study structural, elastic, and dynamical properties to be 90 GPa. For 3C-SiC, our computed elastic constants C11, C12, and C44 , melting temperature

  20. An elastic-support model for enhanced bistable piezoelectric energy harvesting from random vibrations

    NASA Astrophysics Data System (ADS)

    Leng, Y. G.; Gao, Y. J.; Tan, D.; Fan, S. B.; Lai, Z. H.

    2015-02-01

    To overcome the defect of conventional nonlinear piezoelectric cantilever vibration energy harvesters, in this paper we conceive an elastic-support model to study the performance of energy converters under two types of variable-intensity excitation conditions: filtered Gaussian noises and pink noises. When excitation intensity is insufficient, thanks to the system's variable potential function, frequent bistable transition oscillations between two wells occur in elastic-support systems, while only weak oscillations in either well could be observed in rigid-support systems. In practical applications, the structural parameters of energy harvesters are not allowed to make real-time changes. If considered remaining the magnet interval and the spring's elastic stiffness unchanged while receiving stable maximum output voltage, elastic-support systems can be made full use toward variable-intensity filtered Gaussian noises. It has been proven that elastic-support systems are capable of adapting to random excitations with variable intensity, through which maximum power output and sufficient electromechanical energy conversion of the system can be accomplished.

  1. Intermediate energy proton-deuteron elastic scattering

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1973-01-01

    A fully symmetrized multiple scattering series is considered for the description of proton-deuteron elastic scattering. An off-shell continuation of the experimentally known twobody amplitudes that retains the exchange symmeteries required for the calculation is presented. The one boson exchange terms of the two body amplitudes are evaluated exactly in this off-shell prescription. The first two terms of the multiple scattering series are calculated explicitly whereas multiple scattering effects are obtained as minimum variance estimates from the 146-MeV data of Postma and Wilson. The multiple scattering corrections indeed consist of low order partial waves as suggested by Sloan based on model studies with separable interactions. The Hamada-Johnston wave function is shown consistent with the data for internucleon distances greater than about 0.84 fm.

  2. A Forecast of Energy Demand in Japan Considering Asymmetric Price Elasticities

    Microsoft Academic Search

    Yutaka Nagata

    2001-01-01

    Considering asymmetric price elasticities in energy demand functions is an important issue in the field of energy economics. We have estimated past energy demand functions by sector and types of energy in Japan, and confirmed the existence of asymmetric price elasticities in most of the functions. As in the previous studies, when energy prices are falling, price elasticities are insignificant

  3. Radial sensitivity of elastic scattering at near barrier energies for weakly bound and tightly bound nuclei

    SciTech Connect

    Roubos, D.; Pakou, A. [Department of Physics, The University of Ioannina, GR-45110 Ioannina (Greece); Alamanos, N. [CEA-Saclay, DAPNIA-SPhN, Gif-sur-Yvette (France); Rusek, K. [Department of Nuclear Reactions, Andrzej Soltan Institute for Nuclear Studies, Hoza 69, PL-00681 Warsaw (Poland)

    2006-05-15

    The radial sensitivity of elastic scattering for weakly bound ({sup 6}Li, {sup 7}Li, {sup 9}Be) and tightly bound projectiles ({sup 12}C, {sup 16}O) on light and heavy targets ({sup 28}Si, {sup 58}Ni, {sup 118}Sn, {sup 208}Pb, {sup 209}Bi) is sought at barrier energies, taking into account a Woods -Saxon potential and a BDM3Y1 interaction. The results are discussed in terms of the potential anomaly at the coulomb barrier.

  4. Do we understand elastic scattering up to LHC energies?

    SciTech Connect

    Soffer, Jacques [Physics Department, Temple University, Philadelphia, PA 19122-6082 (United States)

    2013-04-15

    The measurements of high energy (bar sign)pp and pp elastic at ISR, SPS, and Tevatron colliders have provided usefull informations on the behavior of the scattering amplitude. A large step in energy domain is accomplished with the LHC collider presently running, giving a unique opportunity to improve our knowledge on the asymptotic regime of the elastic scattering amplitude and to verify the validity of our theoretical approach, to describe the total cross section {sigma}{sub tot}(s), the total elastic cross section {sigma}{sub el}(s), the ratio of the real to imaginary parts of the forward amplitude {rho}(s) and the differential cross section d{sigma} (s,t)/dt.

  5. Universality in Ground State Energy Distributions of Random Elastic Manifolds

    Microsoft Academic Search

    Eira T. Seppälä; Kalle P. Kytölä; Mikko J. Alava

    2002-01-01

    The distribution of ground state energies of elastic manifolds with random-bond disorder is studied numerically in (1+1), (1+2), (1+3), and (2+1) dimensions. (1+1) -dimensional manifolds, or directed polymers, are known to have in a ``single valley'' an energy distribution which is Gaussian close to the mean, and has stretched exponential low and high energy tails with the stretching exponents eta-

  6. Unusual potential behavior for the weakly bound nucleus 9Be in elastic scattering from 208Pb and 209Bi near the threshold

    NASA Astrophysics Data System (ADS)

    Yu, N.; Zhang, H. Q.; Jia, H. M.; Zhang, S. T.; Ruan, M.; Yang, F.; Wu, Z. D.; Xu, X. X.; Bai, C. L.

    2010-07-01

    The elastic scattering angular distributions of the weakly bound 9Be projectile from 208Pb and 209Bi have been measured for 14 beam energies near the threshold from 37 to 50 MeV. The parameters of the optical potential are extracted by means of phenomenological optical model analysis with PTOLEMY. Both of the systems show unusual potential behavior in the vicinity of the Coulomb barrier that the strength of the imaginary (absorptive) part of the potential is increasing (rather than decreasing) with decreasing energy, which is quite different from the results of some previous reports. This unusual threshold phenomenon indicates that the breakup channel is strongly coupled with the elastic channel and has obvious effects on the optical potential. The analyses also show that high precision elastic scattering angular distributions, especially those below the Coulomb barrier, are very important for extracting correct threshold behavior of the optical potential.

  7. Measurements of radiated elastic wave energy from dynamic tensile cracks

    NASA Technical Reports Server (NTRS)

    Boler, Frances M.

    1990-01-01

    The role of fracture-velocity, microstructure, and fracture-energy barriers in elastic wave radiation during a dynamic fracture was investigated in experiments in which dynamic tensile cracks of two fracture cofigurations of double cantilever beam geometry were propagating in glass samples. The first, referred to as primary fracture, consisted of fractures of intact glass specimens; the second configuration, referred to as secondary fracture, consisted of a refracture of primary fracture specimens which were rebonded with an intermittent pattern of adhesive to produce variations in fracture surface energy along the crack path. For primary fracture cases, measurable elastic waves were generated in 31 percent of the 16 fracture events observed; the condition for radiation of measurable waves appears to be a local abrupt change in the fracture path direction, such as occurs when the fracture intersects a surface flaw. For secondary fractures, 100 percent of events showed measurable elastic waves; in these fractures, the ratio of radiated elastic wave energy in the measured component to fracture surface energy was 10 times greater than for primary fracture.

  8. Anomalous Propagation of Elastic Energy within the Moon

    Microsoft Academic Search

    B. I. Pandit; D. C. Tozer

    1970-01-01

    THE records of the seismographs left on the lunar surface by the Apollo 11 and Apollo 12 missions have been discussed by Latham et al.1. From the behaviour immediately following impact of the Apollo 12 ascent stage and similar events present on the records before and after, they have inferred that energy propagation as elastic waves over large distances can

  9. E710, Proton, Antiproton Elastic Scattering at Tevatron Energies

    NASA Astrophysics Data System (ADS)

    Sadr, Sasan

    Experiment E710, located at site E0 of the Tevatron collider at Fermilab, was conceived in order to measure pp elastic scattering. The measured parameters were: the total cross section sigma_{t }, the ratio of the real to the imaginary part of the forward scattering amplitude rho, the nuclear slope parameter B, the nuclear curvature parameter C, the total elastic cross section sigma _{el}, and the single diffractive cross section sigma_{sd} . These measurements were taken at center-of-mass energies of sqrt{s}=1.02 and 1.8 TeV.

  10. Elastic {alpha}-scattering on proton rich nuclei at astrophysically relevant energies

    SciTech Connect

    Fueloep, Zs.; Gyuerky, Gy.; Kiss, G. G.; Mate, Z.; Somorjai, E. [ATOMKI, P.O. Box 51. H-4001 Debrecen (Hungary); Galaviz, D.; Mohr, P.; Zilges, A. [Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Rauscher, T. [Universitaet Basel, CH-4056 Basel (Switzerland)

    2006-07-12

    In order to improve the reliability of statistical model calculations in the region of heavy proton rich nuclei several elastic alpha scattering experiments have been carried out at low bombarding energies on various even-even and semi-magic nuclei. The extracted local optical potential parameters can be compared with the predictions of global alpha potentials. A study on 112,124Sn({alpha},{alpha})112,124Sn has been made to test the global alpha potentials at both the proton and neutron rich sides of an isotopic chain. The present work describes the experimental challenges of high precision scattering experiments at low energy.

  11. Elastic positron-cadmium scattering at low energies

    NASA Astrophysics Data System (ADS)

    Bromley, M. W. J.; Mitroy, J.

    2010-05-01

    The elastic and annihilation cross sections for positron-cadmium scattering are reported up to the positronium-formation threshold (at 2.2 eV). The low-energy phase shifts for the elastic scattering of positrons from cadmium were derived from the bound and pseudostate energies of a very large basis configuration-interaction calculation of the e+-Cd system. The s-wave binding energy is estimated to be 126±42 meV, with a scattering length of Ascat=(14.2±2.1)a0, while the threshold annihilation parameter, Zeff, was 93.9±26.5. The p-wave phase shift exhibits a weak shape resonance that results in a peak Zeff of 91±17 at a collision energy of about 490±50 meV.

  12. Elastic diffractive scattering of nucleons at ultra-high energies

    E-print Network

    A. A. Godizov

    2015-04-08

    A simple Regge-eikonal model with the eikonal represented as a single-reggeon-exchange term is applied to description of the nucleon-nucleon elastic diffractive scattering at ultra-high energies. The range of validity of the proposed approximation is discussed. The model predictions for the proton-proton cross-sections at the collision energy 14 TeV are given.

  13. Proton elastic scattering on light nuclei. I. Energy dependence

    Microsoft Academic Search

    E. Fabrici; S. Micheletti; M. Pignanelli; F. G. Resmini; R. de Leo; G. D'Erasmo; A. Pantaleo; J. L. Escudié; A. Tarrats

    1980-01-01

    Differential cross sections for proton elastic scattering by 15N, 18O, 24Mg, and 40Ar were measured at several proton energies between 14 and 44 MeV. Previous data on 12C, 16O, 24Mg, 28Si, and 40Ca have also been considered. Evidence has been found for a strong enhancement in proton emission at backward angles for scattering by spherical nuclei at incident energies higher

  14. Elastic backscattering measurements for {sup 6}Li+{sup 28}Si at sub- and near-barrier energies

    SciTech Connect

    Zerva, K.; Patronis, N.; Pakou, A.; Aslanoglou, X.; Nicolis, N. G. [Department of Physics, University of Ioannina, GR-45110 Ioannina (Greece); Alamanos, N. [DSM/DAPNIA CEA SACLAY, F-91191 Gif-sur-Yvette (France); Filipescu, D.; Glodariu, T. ['Horia Hulubei' National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania); Kokkoris, M. [National Technical University of Athens, Athens (Greece); La Commara, M. [Dipartimento di Scienze Fisiche and INFN Sezione di Napoli, I-80125, Napoli (Italy); Lagoyannis, A. [National Research Center Demokritos, Agia Paraskevi (Greece); Mazzocco, M. [Dipartimento di Fisica, INFN, I-35131 Padova (Italy); Pierroutsakou, D.; Romoli, M. [INFN Sezione di Napoli, I-80125, Napoli (Italy); Rusek, K. [Heavy Ion Laboratory, University of Warsaw, Pasteura 5a, PL-02-093 Warsaw (Poland)

    2009-07-15

    Elastic backscattering measurements were performed for the weakly bound nucleus {sup 6}Li on a {sup 28}Si target at sub- and near-barrier energies (0.6 to 1.3 V{sub C.B.}). Excitation functions of elastic scattering cross sections were measured at 150 deg. and 170 deg. and the corresponding ratios to Rutherford scattering and relevant barrier distributions were formed. The results are discussed in terms of the potential threshold anomaly and the reaction mechanisms involved.

  15. Application of multiple scattering theory to lower energy elastic nucleon-nucleus reactions

    E-print Network

    Chinn, C R; Thaler, R M; Weppner, S P; Chinn, C R; Elster, Ch; Thaler, R M; Weppner, S P

    1994-01-01

    The optical model potentials for nucleon-nucleus elastic scattering at 65~MeV are calculated for ^{12}C, ^{16}O, ^{28}Si, ^{40}Ca, ^{56}Fe, ^{90}Zr and ^{208}Pb in first order multiple scattering theory, following the prescription of the spectator expansion, where the only inputs are the free NN potentials, the nuclear densities and the nuclear mean field as derived from microscopic nuclear structure calculations. These potentials are used to predict differential cross sections, analyzing powers and spin rotation functions for neutron and proton scattering at 65 MeV projectile energy and compared with available experimental data.

  16. Application of Multiple Scattering Theory to Lower Energy Elastic Nucleon-Nucleus Reactions

    E-print Network

    C. R. Chinn; Ch. Elster; R. M. Thaler; S. P. Weppner

    1994-10-18

    The optical model potentials for nucleon-nucleus elastic scattering at $65$~MeV are calculated for $^{12}$C, $^{16}$O, $^{28}$Si, $^{40}$Ca, $^{56}$Fe, $^{90}$Zr and $^{208}$Pb in first order multiple scattering theory, following the prescription of the spectator expansion, where the only inputs are the free NN potentials, the nuclear densities and the nuclear mean field as derived from microscopic nuclear structure calculations. These potentials are used to predict differential cross sections, analyzing powers and spin rotation functions for neutron and proton scattering at 65 MeV projectile energy and compared with available experimental data.

  17. Quasi-elastic reactions at energies close to the barrier

    SciTech Connect

    Rehm, K.E.

    1988-01-01

    Quasi-elastic reactions induced by medium weight projectiles were measured with good particle resolution using an Enge Split Pole Spectrograph. A large variety of transfer reactions is observed covering the full range from small to large total kinetic energy losses. The data are discussed within the framework of various microscopic models. Several examples of nuclear structure effects in these processes will be discussed. 23 refs., 9 figs.

  18. New Solutions of Half-Space Contact Problems Using Potential Theory, Surface Elasticity and Strain Gradient Elasticity

    E-print Network

    Zhou, Songsheng

    2012-02-14

    - the adhesive contact mechanics, surface elasticity and strain gradient elasticity - are employed to study the mechanical behaviors of a semi-infinite solid induced by the boundary forces. A unified treatment of axisymmetric adhesive contact problems...

  19. Nucleation rate of critical droplets on an elastic string in a Ï⁶ potential

    Microsoft Academic Search

    A. J. Graham; W. C. Kerr

    2004-01-01

    We obtain the nucleation rate of critical droplets for an elastic string moving in a Ï⁶ local potential and subject to noise and damping forces. The critical droplet is a bound soliton-antisoliton pair that carries a section of the string out of the metastable central minimum into one of the stable side minima. The frequencies of small oscillations about the

  20. Nucleation rate of critical droplets on an elastic string in a varphi6 potential

    Microsoft Academic Search

    W. C. Kerr; A. J. Graham

    2004-01-01

    We obtain the nucleation rate of critical droplets for an elastic string moving in a varphi6 local potential and subject to noise and damping forces. The critical droplet is a bound soliton-antisoliton pair that carries a section of the string out of the metastable central minimum into one of the stable side minima. The frequencies of small oscillations about the

  1. Elastic Free Energy Drives the Shape of Prevascular Solid Tumors

    PubMed Central

    Mills, K. L.; Kemkemer, Ralf; Rudraraju, Shiva; Garikipati, Krishna

    2014-01-01

    It is well established that the mechanical environment influences cell functions in health and disease. Here, we address how the mechanical environment influences tumor growth, in particular, the shape of solid tumors. In an in vitro tumor model, which isolates mechanical interactions between cancer tumor cells and a hydrogel, we find that tumors grow as ellipsoids, resembling the same, oft-reported observation of in vivo tumors. Specifically, an oblate ellipsoidal tumor shape robustly occurs when the tumors grow in hydrogels that are stiffer than the tumors, but when they grow in more compliant hydrogels they remain closer to spherical in shape. Using large scale, nonlinear elasticity computations we show that the oblate ellipsoidal shape minimizes the elastic free energy of the tumor-hydrogel system. Having eliminated a number of other candidate explanations, we hypothesize that minimization of the elastic free energy is the reason for predominance of the experimentally observed ellipsoidal shape. This result may hold significance for explaining the shape progression of early solid tumors in vivo and is an important step in understanding the processes underlying solid tumor growth. PMID:25072702

  2. Energy Use in the Australian Manufacturing Industry: An Analysis of Energy Demand Elasticity

    E-print Network

    Energy Use in the Australian Manufacturing Industry: An Analysis of Energy Demand Elasticity Chris in this paper. Energy consumption data was sourced from the Bureau of Resources and Energy Economics' Australian Energy Statistics publication. Price and income data were sourced from the Australian Bureau

  3. Elastic energy of liquid crystals in convex polyhedra

    E-print Network

    A Majumdar; JM Robbins; M Zyskin

    2004-10-01

    We consider nematic liquid crystals in a bounded, convex polyhedron described by a director field n(r) subject to tangent boundary conditions. We derive lower bounds for the one-constant elastic energy in terms of topological invariants. For a right rectangular prism and a large class of topologies, we derive upper bounds by introducing test configurations constructed from local conformal solutions of the Euler-Lagrange equation. The ratio of the upper and lower bounds depends only on the aspect ratios of the prism. As the aspect ratio is varied, the minimum-energy conformal state undergoes a sharp transition from being smooth to having singularities on the edges.

  4. Deuteron-Proton Elastic Scattering at Intermediate Energies

    E-print Network

    N. B. Ladygina

    2007-05-22

    The deuteron-proton elastic scattering has been studied in the multiple scattering expansion formalism. The essential attention has been given to such relativistic problem as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parameterization of the nucleon-nucleon $t$-matrix has been used to take the off-energy shell effects into account. The vector, $A_y,$ and tensor, $A_{yy}$, analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 MeV and 1200 MeV. The obtained results are compared with the experimental data.

  5. Deuteron-proton elastic scattering at intermediate energies

    SciTech Connect

    Ladygina, N. B., E-mail: nladygina@jinr.r [Joint Institute for Nuclear Research (Russian Federation)

    2008-12-15

    The deuteron-proton elastic scattering has been studied in the multiple-scattering expansion formalism. Primary attention has been given to such relativistic problems as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parametrization of the nucleon-nucleon t matrix has been used to take the off-energy-shell effects into account. The vector, A{sub y}, and tensor, A{sub yy}, analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 and 1200 MeV. The obtained results are compared with the experimental data.

  6. Deuteron-proton elastic scattering at intermediate energies

    NASA Astrophysics Data System (ADS)

    Ladygina, N. B.

    2008-12-01

    The deuteron-proton elastic scattering has been studied in the multiple-scattering expansion formalism. Primary attention has been given to such relativistic problems as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parametrization of the nucleon—nucleon t matrix has been used to take the off-energy-shell effects into account. The vector, A y , and tensor, A yy , analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 and 1200 MeV. The obtained results are compared with the experimental data.

  7. Low-energy elastic electron scattering by acetaldehyde

    NASA Astrophysics Data System (ADS)

    Gauf, A.; Navarro, C.; Balch, G.; Hargreaves, L. R.; Khakoo, M. A.; Winstead, C.; McKoy, V.

    2014-02-01

    We report results from a combined experimental and computational study of low-energy electron interactions with acetaldehyde in the gas phase. Differential cross sections for elastic electron scattering were measured at selected incident energies from 1 to 50 eV, while corresponding first-principles calculations were carried out up to 30 eV. Integral and momentum-transfer cross sections were derived from the angle-differential data. The role of resonances in the scattering is examined and comparison is made to previous results for acetaldehyde and for its analogs, formamide and formic acid.

  8. Full-potential calculations of structural, elastic and electronic properties of MgAl2O4 and ZnAl2O4 compounds

    NASA Astrophysics Data System (ADS)

    Khenata, R.; Sahnoun, M.; Baltache, H.; Rérat, M.; Reshak, Ali H.; Al-Douri, Y.; Bouhafs, B.

    2005-09-01

    Theoretical studies of structural, elastic and electronic properties of spinel MgAl2O4 and ZnAl2O4 oxides are presented, using the full-potential linear augmented plane wave (FP-LAPW) method as implemented in the WIEN97 code. In this approach the local density approximation (LDA) is used for the exchange-correlation (XC) potential. Results are given for lattice constant, bulk modulus, and its pressure derivative. The band structure, density of states, pressure coefficients of energy gaps and elastic constants are also given. We present a detailed comparison with available experimental data and previous calculations. Good agreement is found.

  9. Biomass Energy Crops: Massachusetts' Potential

    E-print Network

    Schweik, Charles M.

    Biomass Energy Crops: Massachusetts' Potential Prepared for: Massachusetts Division of Energy;#12;Executive Summary In Massachusetts, biomass energy has typically meant wood chips derived from the region's extensive forest cover. Yet nationally, biomass energy from dedicated energy crops and from crop residues

  10. Alaska's renewable energy potential.

    SciTech Connect

    Not Available

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  11. Knowledge-Based Elastic Potentials for Docking Drugs or Proteins with Nucleic Acids

    PubMed Central

    Ge, Wei; Schneider, Bohdan; Olson, Wilma K.

    2005-01-01

    Elastic ellipsoidal functions defined by the observed hydration patterns around the DNA bases provide a new basis for measuring the recognition of ligands in the grooves of double-helical structures. Here a set of knowledge-based potentials suitable for quantitative description of such behavior is extracted from the observed positions of water molecules and amino acid atoms that form hydrogen bonds with the nitrogenous bases in high resolution crystal structures. Energies based on the displacement of hydrogen-bonding sites on drugs in DNA-crystal complexes relative to the preferred locations of water binding around the heterocyclic bases are low, pointing to the reliability of the potentials and the apparent displacement of water molecules by drug atoms in these structures. The validity of the energy functions has been further examined in a series of sequence substitution studies based on the structures of DNA bound to polyamides that have been designed to recognize the minor-groove edges of Watson-Crick basepairs. The higher energies of binding to incorrect sequences superimposed (without conformational adjustment or displacement of polyamide ligands) on observed high resolution structures confirm the hypothesis that the drug subunits associate with specific DNA bases. The knowledge-based functions also account satisfactorily for the measured free energies of DNA-polyamide association in solution and the observed sites of polyamide binding on nucleosomal DNA. The computations are generally consistent with mechanisms by which minor-groove binding ligands are thought to recognize DNA basepairs. The calculations suggest that the asymmetric distributions of hydrogen-bond-forming atoms on the minor-groove edge of the basepairs may underlie ligand discrimination of G·C from C·G pairs, in addition to the commonly believed role of steric hindrance. The analysis of polyamide-bound nucleosomal structures reveals other discrepancies in the expected chemical design, including unexpected contacts to DNA and modified basepair targets of some ligands. The ellipsoidal potentials thus appear promising as a mathematical tool for the study of drug- and protein-DNA interactions and for gaining new insights into DNA-binding mechanisms. PMID:15501936

  12. The Elastic Strain Energy of Damaged Solids with Applications to Non-Linear Deformation of Crystalline Rocks

    E-print Network

    Lyakhovsky, Vladimir

    materials, damaged rocks, brittle deformation. 1. Introduction Nonlinear elastic deformation of damaged under conditions of brittle deformation have revealed that the elastic properties strongly dependThe Elastic Strain Energy of Damaged Solids with Applications to Non-Linear Deformation

  13. Phenomenological optical potential analysis of proton-carbon elastic scattering at 200 MeV

    NASA Technical Reports Server (NTRS)

    Bidasaria, H. B.; Townsend, L. W.

    1982-01-01

    Differential cross sections for 200 MeV protons elastically scattered from C-12 were analyzed utilizing a local, complex, spin-dependent optical potential with a harmonic well radial dependence. Analyses were performed using the WKB and eikonal approximations. For the latter, first-order corrections to he phase shifts were incorporated to account for the spin-orbit contribution. Large disagreement between theory and experiment was observed when the usual Thomas form for the spin-orbit potential was utilized. Substantial improvement was obtained by allowing the parameters in the central and spin-orbit potential terms to vary independently.

  14. A hyper-stretchable elastic-composite energy harvester.

    PubMed

    Jeong, Chang Kyu; Lee, Jinhwan; Han, Seungyong; Ryu, Jungho; Hwang, Geon-Tae; Park, Dae Yong; Park, Jung Hwan; Lee, Seung Seob; Byun, Myunghwan; Ko, Seung Hwan; Lee, Keon Jae

    2015-05-01

    A hyper-stretchable and deformable elastic-composite generator is developed using a piezoelectric nanocomposite composed of (1-x){Pb(Mg1/3 Nb2/3 )O3 }-x{PbTiO3 } microparticles, carbon nanotubes, a silicone rubber matrix, and very long silver (Ag) nanowire percolation network electrodes. To date, this nanogenerator sets world records for output performance, strain capacity, mechanical stability, and commercial feasibility in the research field for stretchable and deformable piezoelectric energy harvesters. PMID:25824939

  15. Elastic scattering of 9Li on 208Pb at energies around the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Cubero, M.; Fernández-García, J. P.; Lay, J. A.; Acosta, L.; Alcorta, M.; Alvarez, M. A. G.; Borge, M. J. G.; Buchmann, L.; Diget, D. G.; Fulton, B.; Fynbo, H. O. U.; Galaviz, D.; Gómez-Camacho, J.; Martel, I.; Moro, A. M.; Mukha, I.; Nilsson, T.; Sánchez-Benítez, A. M.; Shotter, A.; Tengblad, O.; Walden, P.

    2011-10-01

    We have studied the dynamical effects of the halo structure of 11Li on the scattering on heavy targets at energies around the Coulomb barrier. This experiment was performed at ISAC-II at TRIUMF with a world record in production of the post-accelerated 11Li beam. As part of this study we report here on the first measurement of the elastic cross section of the core nucleus, i.e. 9Li on 208Pb, at energies around the Coulomb barrier. A preliminary optical model analysis has been performed in order to extract a global optical potential to describe the measured angular distributions.

  16. Physics 321 Energy Conservation Potential Energy in

    E-print Network

    Hart, Gus

    Physics 321 Hour 7 Energy Conservation ­ Potential Energy in One Dimension WorkEnergy Theorem all Ts, Us. T+U = E = E0. Gives v(y). Conservation of Energy II A sphere rolls without slipping down T and U. 2) Write equations of constraint among variables. #12;Conservation of Energy III (b) A sphere

  17. Elastic scattering of low-energy electrons by BF3

    NASA Astrophysics Data System (ADS)

    Pastega, Diego F.; da Costa, Romarly F.; Lima, Marco A. P.; Bettega, Márcio H. F.

    2014-02-01

    We present integral, differential and momentum transfer cross sections for elastic scattering of low-energy electrons by boron trifluoride molecules. The cross sections were obtained with the Schwinger multichannel method implemented with pseudopotentials. The calculations were performed in the static-exchange and in the static-exchange-polarization approximations for energies from 0.1 to 10 eV. Our results indicate that BF3 has a shape resonance in the B 2 symmetry located at around 3.5 eV, in agreement with the experimental measurements of 3.8 eV, 3.54 eV and of 3.6 eV reported by [M. Tronc et al., J. Phys. B 15, L253 (1982)], by [J.A. Tossell et al., Int. J. Quantum Chem. 29, 1117 (1986)] and by [C. Szmytkowski et al., J. Chem. Phys. 121, 1790 (2004)] respectively. We also report a Ramsauer-Townsend minimum at around 0.7 eV, in conformity with the observations of [S.R. Hunter et al., J. Appl. Phys. 65, 1858 (1989); Z. Nikitovi? et al., Acta Phys. Polon. A 117, 748 (2010)], and [P.X. Hien et al., J. Phys. Soc. Jpn 82, 034301 (2013)]. Our elastic integral cross section is compared with calculated elastic cross sections of [J.A. Tossell et al., Int. J. Quantum Chem. 29, 1117 (1986)] and of [M. Radmilovi?-Radjenovi? et al., Publ. Astron. Obs. Belgrade 84, 57 (2008)] and with the experimental total cross section data of [C. Szmytkowski et al., J. Chem. Phys. 121, 1790 (2004)]. Although all these studies reported the presence of the shape resonance, there are some discrepancies in the magnitude and shape among the cross sections.

  18. On the asymptotic derivation of Winkler-type energies from 3D elasticity

    E-print Network

    Andrés A León Baldelli; Blaise Bourdin

    2014-10-02

    We show how bilateral, linear, elastic foundations (i.e. Winkler foundations) often regarded as heuristic, phenomenological models, emerge asymptotically from standard, linear, three-dimensional elasticity. We study the parametric asymptotics of a non-homogeneous linearly elastic bi-layer attached to a rigid substrate as its thickness vanishes, for varying thickness and stiffness ratios. By using rigorous arguments based on energy estimates, we provide a first rational and constructive justification of reduced foundation models. We establish the variational weak convergence of the three-dimensional elasticity problem to a two-dimensional one, of either a "membrane over in-plane elastic foundation", or a "plate over transverse elastic foundation". These two regimes are function of the only two parameters of the system, and a phase diagram synthesizes their domains of validity. Moreover, we derive explicit formulae relating the effective coefficients of the elastic foundation to the elastic and geometric parameters of the original three-dimensional system.

  19. Potential For Energy Conservation

    E-print Network

    Kumar, A.

    1981-01-01

    The largest single area for industrial energy conservation is in the improvement of combustion efficiencies for heaters and boilers. A number of methods can be employed to recover heat. The most common are by use of recuperative air preheaters...

  20. IOSA investigations of the effects of potential surface topography upon elastic and inelastic scattering and rotational relaxation in the (He, CO2) system

    Microsoft Academic Search

    P. M. Agrawal; L. M. Raff

    1981-01-01

    The effect of potential surface topography upon elastic and inelastic scattering has been investigated using the infinite-order sudden approximation (IOSA) to compute total differential and integral cross sections, state-to-state cross sections, and the relaxation rates of depleted levels in the (He, COâ) and (³He, COâ) rigid rotor systems on six different potential energy surfaces that include three surfaces obtained from

  1. IOSA investigations of the effects of potential surface topography upon elastic and inelastic scattering and rotational relaxation in the (He, CO2) system

    Microsoft Academic Search

    P. M. Agrawal; L. M. Raff

    1981-01-01

    The effect of potential surface topography upon elastic and inelastic scattering has been investigated using the infinite-order sudden approximation (IOSA) to compute total differential and integral cross sections, state-to-state cross sections, and the relaxation rates of depleted levels in the (He, CO2) and (3He, CO2) rigid rotor systems on six different potential energy surfaces that include three surfaces obtained from

  2. Application of multiple scattering theory to lower-energy elastic nucleon-nucleus scattering

    NASA Astrophysics Data System (ADS)

    Chinn, C. R.; Elster, Ch.; Thaler, R. M.; Weppner, S. P.

    1995-03-01

    The optical model potentials for nucleon-nucleus elastic scattering at 65 meV are calculated for 12C, 16O, 28Si, 40Ca, 56Fe, 90Zr, and 208Pb in first-order multiple scattering theory, following the prescription of the spectator expansion, where the only inputs are the free nucleon-nucleon (NN) potentials, the nuclear densities, and the nuclear mean field as derived from microscopic nuclear structure calculations. These potentials are used to predict differential cross sections, analyzing powers, and spin rotation functions for neutron and proton scattering at 65 MeV projectile energy and compared with available experimental data. The theoretical curves are in very good agreement with the data. The modification of the propagator due to the coupling of the struck nucleon to the residual nucleus is seen to be significant at this energy and invariably improves the congruence of theoretical prediction and measurement.

  3. Low-energy elastic electron scattering from furan

    NASA Astrophysics Data System (ADS)

    Khakoo, M. A.; Muse, J.; Ralphs, K.; da Costa, R. F.; Bettega, M. H. F.; Lima, M. A. P.

    2010-06-01

    We report normalized experimental and theoretical differential cross sections for elastic electron scattering by C4H4O (furan) molecules from a collaborative project between several Brazilian theoretical groups and an experimental group at California State Fullerton, USA. The measurements are obtained by using the relative flow method with helium as the standard gas and a thin aperture target gas collimating source. The relative flow method is applied without the restriction imposed by the relative flow pressure condition on helium and the unknown gas. The experimental data were taken at incident electron energies of 1, 1.5, 1.73, 2, 2.7, 3, 5, 7, 10, 20, 30, and 50 eV and covered the angular range between 10° and 130°. The measurements verify observed ?* shape resonances at 1.65±0.05eV and 3.10±0.05 eV scattering energies, in good agreement with the transmission electron data of Modelli and Burrow [J. Phys. Chem. AJPCAFH 1089-563910.1021/jp048759a 108, 5721 (2004)]. Furthermore, the present results also indicated both resonances dominantly in the d-wave channel. The differential cross sections are integrated in the standard way to obtain integral elastic cross sections and momentum transfer cross sections. The calculations employed the Schwinger multichannel method with pseudopotentials and were performed in the static-exchange and in the static-exchange plus polarization approximations. The calculated integral and momentum transfer cross sections clearly revealed the presence of two shape resonances located at 1.95 and 3.56 eV and ascribed to the B1 and A2 symmetries of the C2v point group, respectively, in very good agreement with the experimental findings. Overall agreement between theory and experiment regarding the differential, momentum transfer, and integral cross sections is very good, especially for energies below 10 eV.

  4. Material selection for elastic energy absorption in origami-inspired compliant corrugations

    NASA Astrophysics Data System (ADS)

    Tolman, Sean S.; Delimont, Isaac L.; Howell, Larry L.; Fullwood, David T.

    2014-09-01

    Elastic absorption of kinetic energy and distribution of impact forces are required in many applications. Recent attention to the potential for using origami in engineering may provide new methods for energy absorption and force distribution. A three-stage strategy is presented for selecting materials for such origami-inspired designs that can deform to achieve a desired motion without yielding, absorb elastic strain energy, and be lightweight or cost effective. Two material indices are derived to meet these requirements based on compliant mechanism theory. Finite element analysis is used to investigate the effects of the material stiffness in the Miura-ori tessellation on its energy absorption and force distribution characteristics compared with a triangular wave corrugation. An example is presented of how the method can be used to select a material for a general energy absorption application of the Miura-ori. Whereas the focus of this study is the Miura-ori tessellation, the methods developed can be applied to other tessellated patterns used in energy absorbing or force distribution applications.

  5. Scaling of elastic energy storage in mammalian limb tendons: do small mammals really lose out?

    PubMed

    Bullimore, Sharon R; Burn, Jeremy F

    2005-03-22

    It is widely believed that elastic energy storage is more important in the locomotion of larger mammals. This is based on: (a) comparison of kangaroos with the smaller kangaroo rat; and (b) calculations that predict that the capacity for elastic energy storage relative to body mass increases with size. Here we argue that: (i) data from kangaroos and kangaroo rats cannot be generalized to other mammals; (ii) the elastic energy storage capacity relative to body mass is not indicative of the importance of elastic energy to an animal; and (iii) the contribution of elastic energy to the mechanical work of locomotion will not increase as rapidly with size as the mass-specific energy storage capacity, because larger mammals must do relatively more mechanical work per stride. We predict how the ratio of elastic energy storage to mechanical work will change with size in quadrupedal mammals by combining empirical scaling relationships from the literature. The results suggest that the percentage contribution of elastic energy to the mechanical work of locomotion decreases with size, so that elastic energy is more important in the locomotion of smaller mammals. This now needs to be tested experimentally. PMID:17148127

  6. Anchoring energy and orientational elasticity of a ferroelectric liquid crystal

    SciTech Connect

    Kaznacheev, A. V., E-mail: kazna@ineos.ac.ru [Russian Academy of Sciences, Nesmeyanov Institute of Organoelement Compounds (Russian Federation); Pozhidaev, E. P., E-mail: epozhidaev@mail.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2012-06-15

    The dielectric susceptibility of a helix-free ferroelectric liquid crystal layer has been experimentally and theoretically studied as a function of the layer thickness. The investigation has been performed on the inner branch of the polarization hysteresis loop, in the region of a linear dependence of the polarization on the electric field. The experimental results are explained using the notion of effective layer thickness, which involves the characteristic distance {xi} over which the orienting effect of interfaces is operative. Comparison of the experimental data and theoretical results made it possible to estimate this distance as {xi} = 41 {mu}m and evaluate the anchoring energy (W = 2.8 Multiplication-Sign 10{sup -3}-1.1 Multiplication-Sign 10{sup -2} J/m{sup 2}) and the intralayer elastic constant (K Double-Prime Almost-Equal-To 1 Multiplication-Sign 10{sup -8}-3 Multiplication-Sign 10{sup -7} N).

  7. Low-energy electron elastic scattering cross sections for excited Au and Pt atoms

    NASA Astrophysics Data System (ADS)

    Felfli, Zineb; Eure, Amanda R.; Msezane, Alfred Z.; Sokolovski, Dmitri

    2010-05-01

    Electron elastic total cross sections (TCSs) and differential cross sections (DCSs) in both impact energy and scattering angle for the excited Au and Pt atoms are calculated in the electron impact energy range 0 ? E ? 4.0 eV. The cross sections are found to be characterized by very sharp long-lived resonances whose positions are identified with the binding energies of the excited anions formed during the collisions. The recent novel Regge-pole methodology wherein is embedded through the Mulholland formula the electron-electron correlations is used together with a Thomas-Fermi type potential incorporating the crucial core-polarization interaction for the calculations of the TCSs. The DCSs are evaluated using a partial wave expansion. The Ramsauer-Townsend minima, the shape resonances and the binding energies of the excited Au - and Pt - anions are extracted from the cross sections, while the critical minima are determined from the DCSs.

  8. Analysis of Dermal Elastic Fibers in the Absence of Fibulin-5 Reveals Potential Roles for Fibulin-5 in Elastic Fiber Assembly

    PubMed Central

    Choi, Jiwon; Bergdahl, Andreas; Zheng, Qian; Starcher, Barry; Yanagisawa, Hiromi; Davis, Elaine C.

    2009-01-01

    Fibulin-5 is a 66 kDa modular, extracellular matrix protein that localizes to elastic fibers. Although in vitro protein-protein binding studies have shown that fibulin-5 binds many proteins involved in elastic fiber formation, the specific role of fibulin-5 in elastogenesis remains unclear. To provide a more detailed analysis of elastic fiber assembly in the absence of fibulin-5, the dermis of wild-type and fibulin-5 gene knockout (Fbln5?/?) mice was examined with electron microscopy (EM). Although light microscopy showed apparently normal elastic fibers near the hair follicles and the absence of elastic fibers in the intervening dermis of the Fbln5?/? mouse, EM revealed the presence of aberrantly assembled elastic fibers in both locales. Instead of the elastin being incorporated into the microfibrillar scaffold, the elastin appeared as globules juxtaposed to the microfibrils. Desmosine analysis showed significantly lower levels of mature cross-linked elastin in the the Fbln5?/? dermis, however, gene expression levels for tropoelastin and fibrillin-1, the major elastic fiber components, were unaffected. Based on these results, the nature of tropoelastin cross-linking was investigated using domain specific antibodies to lysyl oxidase like-1 (LOXL-1). Immunolocalization with an antibody to the N-terminal pro-peptide, which is cleaved to generate the active enzyme, revealed abundant staining in the Fbln5?/? dermis and no staining in the wild-type dermis. Overall, these results suggest two previously unrecognized functions for fibulin-5 in elastogenesis; first, to limit the extent of aggregation of tropoelastin monomers and/or coacervates and aid in the incorporation of elastin into the microfibril bundles, and second, to potentially assist in the activation of LOXL-1. PMID:19321153

  9. LHC Physics Potential versus Energy

    SciTech Connect

    Quigg, Chris; /Fermilab

    2009-08-01

    Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u{bar d}, and qq interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes.

  10. Calculation of Elastic Constants of Ag\\/Pd Superlattice Thin Films by Molecular Dynamics with Many-Body Potentials

    Microsoft Academic Search

    Ning Gao; Wen-Sheng Lai

    2006-01-01

    The calculation of elastic constants of Ag\\/Pd superlattice thin films by molecular dynamics simulations with many-body potentials is presented. It reveals that the elastic constants C11 and C55 increase with decreasing modulation wavelength ? of the films, which is consistent with experiments. However, the change of C11 and C55 with ? is found to be around the values determined by

  11. Development of bond-order potentials that can reproduce the elastic constants and melting point of silicon for classical molecular dynamics simulation

    Microsoft Academic Search

    T. Kumagai; S. Izumi; S. Hara; S. Sakai

    2007-01-01

    The Tersoff potential is one of the most widely used interatomic potentials for silicon. However, its poor description of the elastic constants and melting point of diamond silicon is well known. In this research, three bond-order type interatomic potentials have been developed: the first one is fitted to the elastic constants by employing the Tersoff potential function form, the second

  12. Curve crossing for low-energy elastic scattering of He/+/ by Ne.

    NASA Technical Reports Server (NTRS)

    Bobbio, S. M.; Doverspike, L. D.; Champion, R. L.

    1973-01-01

    The perturbation seen in the experimental differential elastic-scattering cross section for the 40-eV He/+/ + Ne system has been attributed to a single crossing of two intermolecular potential-energy curves. A new theoretical treatment of the curve-crossing problem, namely, that of Delos and Thorson, is employed to obtain the crossing probabilities and phases associated with the crossing. These are determined by utilizing ab initio potentials involved in the crossing and are further used in a partial-wave calculation of the cross section, which is compared with our experiment. The origin of the oscillatory structure observed in the differential cross section is discussed in semiclassical terms by defining the problem in terms of two pseudo-deflection-functions. A rainbow effect is shown to be related to a particular feature (a maximum rather than a minimum) of these deflection functions.

  13. Wind Energy: Progress and Potential

    Microsoft Academic Search

    KAMIL KAYGUSUZ

    2004-01-01

    This article reviews the progress made by wind energy in the last 10 years, and discusses the potential of this technology. During the last decade of the 20th century, grid-connected wind capacity worldwide has doubled approximately every three years. Due to the fast market development, wind turbine technology has experienced an important evolution over time. Some of the countries with

  14. Calculation of low-energy elastic cross sections for electron-CF4 scattering

    NASA Astrophysics Data System (ADS)

    Gianturco, F. A.; Lucchese, R. R.; Sanna, N.

    1994-05-01

    A new computational approach has been used to evaluate the rotationally summed, vibronically elastic integral cross sections from the scattering of slow electrons (energy ranging from 1.0 eV up to 40.0 eV) by tetrafluoromethane molecules in the gas phase. The various symmetry components have been analyzed using the exact static exchange approximation and also by including a nonempirical, model polarization potential employed before by our group. A comparison with earlier calculations and with existing experiments allows us to assign the symmetries of the shape resonances in the 5-30 eV energy region which are seen by experiments and are also shown by the present calculations.

  15. Experimental studies of the influence of beam composition on elastic scattering yields of low energy sup 20 Ne ions

    SciTech Connect

    Martin, A.

    1991-01-01

    The yields of elastically scattered ({theta}{sub lab} = 138{degree}) {sup 20}Ne ions from the surfaces of polycrystalline elemental samples of Ag, Sn, Au, and Pd have been measured as a function of the ionization potential V{sub i}, and the incident beam current, I{sub 0}, in the ion gun over a range of incident beam energies from 800 to 2,100 eV. Ion Scattering Spectroscopy (ISS) data were accumulated for elastically scattered incident Ne{sup +} ions and, when practical, for Ne{sup ++} ions partially neutralizing and scattering elastically in the singly charged state. The data indicate that a threshold for the elastic scattering yield exists for all the samples studied at V{sub i} {ge} 80V which is exhibited by a shift in the peak position of the normalized yield {tilde Y} to a lower (50-100 eV) incident beam energy. Upon consideration of the data, and in the light of calculations based upon a classical theory of ionization cross sections, the effect is attributed to the nature of the cross section for the formation of singly ionized {sup 20}Ne due to electronic collisions in the ion gun. The absolute elastic yields for the samples are compared, with Pd exhibiting the lowest yield at all values of the experimental parameters and with Ag, Au, and Sn yields greater by factors of approximately 5, 10 and 15 respectively. The elastic scattering yield vs. incident energy for Pd exhibits unique among the samples in this study and among those found in the literature. The implications of this for the theory of neutralization in ISS are briefly discussed.

  16. On granular elasticity.

    PubMed

    Sun, Qicheng; Jin, Feng; Wang, Guangqian; Song, Shixiong; Zhang, Guohua

    2015-01-01

    Mesoscopic structures form in dense granular materials due to the self-organisation of the constituent particles. These structures have internal structural degrees of freedom in addition to the translational degree of freedom. The resultant granular elasticity, which exhibits intrinsic variations and inevitable relaxation, is a key quantity that accounts for macroscopic solid- or fluid-like properties and the transitions between them. In this work, we propose a potential energy landscape (PEL) with local stable basins and low elastic energy barriers to analyse the nature of granular elasticity. A function for the elastic energy density is proposed for stable states and is further calibrated with ultrasonic measurements. Fluctuations in the elastic energy due to the evolution of internal structures are proposed to describe a so-called configuration temperature T(c) as a counterpart of the classical kinetic granular temperature T(k) that is attributed to the translational degrees of freedom. The two granular temperatures are chosen as the state variables, and a fundamental equation is established to develop non-equilibrium thermodynamics for granular materials. Due to the relatively low elastic energy barrier in the PEL, granular elasticity relaxes more under common mechanical loadings, and a simple model based on mean-field theory is developed to account for this behaviour. PMID:25951049

  17. Pole structure from energy-dependent and single-energy fits to $?N$ elastic scattering data

    E-print Network

    Alfred Švarc; Mirza Hadžimehmedovi?; Hedim Osmanovi?; Jugoslav Stahov; Ron L. Workman

    2015-01-28

    The pole structure of the current GW/SAID partial-wave analysis of elastic $\\pi N$ scattering and $\\eta N$ production data is studied. Pole positions and residues are extracted from both the energy-dependent and single-energy fits, using two different methods. For the energy-dependent fits, both contour integration and a Laurent+Pietarinen approach are used. In the case of single-energy fits, the Laurent+Pietarinen approach is used. Errors are estimated and the two sets of results are compared to other recent and older fits to data.

  18. Cross-linking cellulose nanofibrils for potential elastic cryo-structured gels

    NASA Astrophysics Data System (ADS)

    Syverud, Kristin; Kirsebom, Harald; Hajizadeh, Solmaz; Chinga-Carrasco, Gary

    2011-12-01

    Cellulose nanofibrils were produced from P. radiata kraft pulp fibers. The nanofibrillation was facilitated by applying 2,2,6,6-tetramethylpiperidinyl-1-oxyl-mediated oxidation as pretreatment. The oxidized nanofibrils were cross-linked with polyethyleneimine and poly N-isopropylacrylamide- co-allylamine- co-methylenebisacrylamide particles and were frozen to form cryo-structured gels. Samples of the gels were critical-point dried, and the corresponding structures were assessed with scanning electron microscopy. It appears that the aldehyde groups in the oxidized nanofibrils are suitable reaction sites for cross-linking. The cryo-structured materials were spongy, elastic, and thus capable of regaining their shape after a given pressure was released, indicating a successful cross-linking. These novel types of gels are considered potential candidates in biomedical and biotechnological applications.

  19. Study of elastic and inelastic pion-nucleus scattering using the microscopic model of optical potential

    NASA Astrophysics Data System (ADS)

    Lukyanov, V. K.; Zemlyanaya, E. V.; Lukyanov, K. V.; Ellithi, A. Y.; Abdul-Magead, I. A. M.

    2015-05-01

    The pion-nucleus microscopic optical potential (OP), defined by the pion-nucleon scattering amplitude and by the generalized density distribution of a target nucleus that incudes internal degrees of freedom, is applied to construct the pion-nucleus differential cross-sections of elastic and inelastic scattering on the nuclei 28Si, 58Ni, 208Pb at Tlab = 291 MeV. Calculations are based on the relativistic wave equation and thus relativistic effects and distortions on the relative motion wave functions are taken into account. The respective experimental data are analyzed and the in-medium parameters of the elementary ?N-amplitude are established and compared with those from the pion scattering on free nucleons.

  20. Physics 321 Energy Conservation Potential Energy in

    E-print Network

    Hart, Gus

    2 = = = + = = This is a useful relation ­ but we'll go one step further: = = |2 1 = = · Positive no explicit time dependence, we can define a potential energy. Otherwise, we can not. In general = Vector Calculus in Mathematica vec_calc_ex.nb #12;

  1. LHC Predictions from an extended theory with Elastic, Inelastic, and Path Length Fluctuating Energy Loss

    E-print Network

    William A. Horowitz

    2007-02-27

    We present the LHC predictions for the WHDG model of radiative, elastic, and path length fluctuating energy loss. We find the pT dependence of RAA is qualitatively very different from AWS-based energy loss extrapolations to the LHC; the large pT reach of the year one data at the LHC should suffice to distinguish between the two. We also discuss the importance of requiring a first elastic scatter before any medium-induced elastic or radiative loss occurs, a necessary physical effect not considered in any previous models.

  2. The form of the elastic energy loss probability distribution in a static medium

    E-print Network

    Jussi Auvinen; Thorsten Renk

    2011-12-08

    We examine the probability distributions P(E,t) of the energy of a hard parton traveling in a partonic medium of constant density for a time t while undergoing elastic 2-to-2 pQCD interactions using a Monte-Carlo model. The form of these distributions is found to be non-Gaussian, confirming results by other groups with similarly detailed models and challenging the validity of the widely used diffusion approximation in elastic energy loss modeling.

  3. Phason-elastic energy in a model quasicrystal Ulrich Koschella, Franz Gahler, Johannes Roth, and Hans-Rainer Trebin

    E-print Network

    Gähler, Franz

    potentials, using molecular dynamics relax- ation simulations. One of the phason elastic con- stants turned In a previous paper [1] we have measured the five generalized phason-phonon elastic constants at zero motifs. To improve on those results, we analyze in Sec- tion 2 the phason elastic constants in dependence

  4. The 106Cd(alpha,alpha)106Cd elastic scattering in a wide energy range for gamma-process studies

    E-print Network

    Ornelas, A; Mohr, P; Galaviz, D; Fülöp, Zs; Gyürky, Gy; Máté, Z; Rauscher, T; Somorjai, E; Sonnabend, K; Zilges, A

    2015-01-01

    Alpha elastic scattering angular distributions of the 106Cd(alpha,alpha)106Cd reaction were measured at three energies around the Coulomb barrier to provide a sensitive test for the alpha + nucleus optical potential parameter sets. Furthermore, the new high precision angular distributions, together with the data available from the literature were used to study the energy dependence of the locally optimized {\\alpha}+nucleus optical potential in a wide energy region ranging from E_Lab = 27.0 MeV down to 16.1 MeV. The potentials under study are a basic prerequisite for the prediction of alpha-induced reaction cross sections and thus, for the calculation of stellar reaction rates used for the astrophysical gamma process. Therefore, statistical model predictions using as input the optical potentials discussed in the present work are compared to the available 106Cd + alpha cross section data.

  5. The 106Cd(alpha,alpha)106Cd elastic scattering in a wide energy range for gamma-process studies

    E-print Network

    A. Ornelas; G. G. Kiss; P. Mohr; D. Galaviz; Zs. Fülöp; Gy. Gyürky; Z. Máté; T. Rauscher; E. Somorjai; K. Sonnabend; A. Zilges

    2015-04-29

    Alpha elastic scattering angular distributions of the 106Cd(alpha,alpha)106Cd reaction were measured at three energies around the Coulomb barrier to provide a sensitive test for the alpha + nucleus optical potential parameter sets. Furthermore, the new high precision angular distributions, together with the data available from the literature were used to study the energy dependence of the locally optimized {\\alpha}+nucleus optical potential in a wide energy region ranging from E_Lab = 27.0 MeV down to 16.1 MeV. The potentials under study are a basic prerequisite for the prediction of alpha-induced reaction cross sections and thus, for the calculation of stellar reaction rates used for the astrophysical gamma process. Therefore, statistical model predictions using as input the optical potentials discussed in the present work are compared to the available 106Cd + alpha cross section data.

  6. Low-energy elastic electron scattering by tetrafluoromethane (CF4)

    NASA Astrophysics Data System (ADS)

    Winstead, Carl; Sun, Qiyan; McKoy, Vincent

    1993-01-01

    We report cross sections for electronically elastic electron scattering by CF4 from 1 to 40 eV, calculated within the static-exchange approximation using the Schwinger multichannel method. Although the static-exchange approximation does not give results that are accurate in detail below 20 eV, it is useful in understanding resonant features in the elastic and vibrationally inelastic cross sections. Above 20 eV, where the static-exchange approximation is more reliable, we derive a dissociation cross section in fair agreement with experiment by subtracting our result from the measured total cross section. We compare our integral and differential cross sections with the results of recent elastic and vibrationally inelastic scattering experiments.

  7. Experimental study of the variation of alpha elastic scattering cross sections along isotopic and isotonic chains at low energies

    SciTech Connect

    Kiss, G. G.; Gyuerky, Gy.; Elekes, Z.; Fueloep, Zs.; Somorjai, E. [Institute of Nuclear Research (ATOMKI), H-4001 Debrecen, POB. 51 (Hungary); Galaviz, D. [Instituto de Estructura de la Materia, E-28006 Madrid (Spain); Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Sonnabend, K.; Zilges, A. [Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Mohr, P. [Strahlenterapie, Diakonie-Klinikum, D-74523 Schwaebisch Hall (Germany); Goerres, J.; Wiescher, M. [University of Notre Dame, Notre Dame, Indiana 46556 (United States); Oezkan, N.; Gueray, T. [Kocaeli University, Department of Physics, TR-41380 Umuttepe, Kocaeli (Turkey); Yalcin, C. [Kocaeli University, Department of Physics, TR-41380 Umuttepe, Kocaeli (Turkey); Institute of Nuclear Research (ATOMKI), H-4001 Debrecen, POB. 51 (Hungary); Avrigeanu, M. [''Horia Hulubei'' National Institute for Physics and Nuclear Engineering, 76900 Bucharest (Romania)

    2008-05-21

    To improve the reliability of statistical model calculations in the region of heavy proton rich isotopes alpha elastic scattering experiments have been performed at ATOMKI, Debrecen, Hungary. The experiments were carried out at several energies above and below the Coulomb barrier with high precision. The measured angular distributions can be used for testing the predictions of the global and regional optical potential parameter sets. Moreover, we derived the variation of the elastic alpha scattering cross section along the Z = 50 ({sup 112}Sn-{sup 124}Sn) isotopic and N = 50 ({sup 89}Y-{sup 92}Mo) isotonic chains. In this paper we summarize the efforts to provide high precision experimental angular distributions for several A{approx_equal}100 nuclei to test the global optical potential parameterizations applied to p-process network calculations.

  8. On the non-uniform motion of dislocations: The retarded elastic fields, the retarded dislocation tensor potentials and the Liénard-Wiechert tensor potentials

    E-print Network

    Markus Lazar

    2012-10-11

    The purpose of this paper is the fundamental theory of the non-uniform motion of dislocations in two and three space-dimensions. We investigate the non-uniform motion of an arbitrary distribution of dislocations, a dislocation loop and straight dislocations in infinite media using the theory of incompatible elastodynamics. The equations of motion are derived for non-uniformly moving dislocations. The retarded elastic fields produced by a distribution of dislocations and the retarded dislocation tensor potentials are determined. New fundamental key-formulae for the dynamics of dislocations are derived (Jefimenko type and Heaviside-Feynman type equations of dislocations). In addition, exact closed-form solutions of the elastic fields produced by a dislocation loop are calculated as retarded line integral expressions for subsonic motion. The fields of the elastic velocity and elastic distortion surrounding the arbitrarily moving dislocation loop are given explicitly in terms of the so-called three-dimensional elastodynamic Li\\'enard-Wiechert tensor potentials. The two-dimensional elastodynamic Li\\'enard-Wiechert tensor potentials and the near-field approximation of the elastic fields for straight dislocations are calculated. The singularities of the near-fields of accelerating screw and edge dislocations are determined.

  9. Resonances in low-energy electron elastic cross sections for lanthanide atoms

    NASA Astrophysics Data System (ADS)

    Felfli, Z.; Msezane, A. Z.; Sokolovski, D.

    2009-01-01

    Total and Mulholland partial cross sections for the elastic scattering of electrons from the lanthanide atoms lanthanum to lutetium are calculated for the electron impact energy range 0?E?1eV . The recently developed Regge-pole methodology, which naturally embodies the crucial electron correlation effects together with a Thomas-Fermi-type potential incorporating the vital core-polarization interaction are used for the calculations. Dramatically sharp resonances are found to characterize the near-threshold electron elastic scattering total and Mulholland partial cross sections, whose energy positions are identified with the electron affinities (EA’s) of these atoms through a close scrutiny of the imaginary part of the complex angular momentum. The unambiguous extracted EA values of the lanthanide atoms vary from a low value of 0.016eV for the Tm atom to a high value of 0.631eV for the Pr atom; none is predicted to have a lower EA value than the former. All the negative ions of the lanthanide atoms can be classified through their binding energies (BE’s) as weakly bound negative ions (BE’s <1.0eV ), while only three qualify to be classified as tenuously bound (BE’ <0.1eV ). Ramsauer-Townsend minima, shape resonances, and the Wigner threshold behavior for these lanthanides are also determined. Comparisons of the present calculated EA’s with those from various experimental measurements and other theoretical calculations are presented and discussed. In particular, our extracted EA value for the complicated open d - and f -subshell Ce atom agrees excellently with the most recently measured [Walter , Phys. Rev. A 76, 052702 (2007)] and calculated values, while for Nd and Eu the agreement with the latest calculated values of O’Malley and Beck [Phys. Rev. A 77, 012505 (2008); Phys. Rev. A 78, 012510 (2008)] is outstanding. These agreements give great credence to the already demonstrated predictive power of the Regge-pole methodology to extract unambiguous and reliable binding energies for tenuously bound and complicated open-shell negative ionic systems, requiring no a priori knowledge of the EA values whatsoever. This new perspective to the EA determination of atoms from low-energy electron elastic scattering resonances promises far-reaching implications for future accurate and reliable theoretical EA values, even for small molecules and clusters.

  10. Elastic energy of a deformable earth: General expression

    Microsoft Academic Search

    Juan Getino; Facultad Ciencias

    1992-01-01

    This work is the first in the second part of a project dedicated to elaborating a Hamiltonian theory for the rotational motion of a deformable Earth. In the four works which make up the first part the basis of this theory is laid down, studying the effects produced when the Earth's elastic mantle is deformed by lunisolar attraction. More specifically,

  11. A constitutive framework based on elastic and internal energy degradation

    Microsoft Academic Search

    G. Borino; S. Del Linz; G. Giambanco

    2001-01-01

    A general constitutive framework is presented capable of representing different irreversible deformation modes, like plasticity, elastic damage, complex evolution of the hardening properties and the induced coupling effects. The formulation can be framed in the generalized standard material models with internal variables and multiple dissipative activation functions. The formulation is thermodynamically consistent and the state laws, the structure of the

  12. The cross-bridge spring: can cool muscles store elastic energy?

    PubMed

    George, N T; Irving, T C; Williams, C D; Daniel, T L

    2013-06-01

    Muscles not only generate force. They may act as springs, providing energy storage to drive locomotion. Although extensible myofilaments are implicated as sites of energy storage, we show that intramuscular temperature gradients may enable molecular motors (cross-bridges) to store elastic strain energy. By using time-resolved small-angle x-ray diffraction paired with in situ measurements of mechanical energy exchange in flight muscles of Manduca sexta, we produced high-speed movies of x-ray equatorial reflections, indicating cross-bridge association with myofilaments. A temperature gradient within the flight muscle leads to lower cross-bridge cycling in the cooler regions. Those cross-bridges could elastically return energy at the extrema of muscle lengthening and shortening, helping drive cyclic wing motions. These results suggest that cross-bridges can perform functions other than contraction, acting as molecular links for elastic energy storage. PMID:23618763

  13. Dirac optical potentials for nucleon scattering by 208Pb at intermediate energies

    NASA Astrophysics Data System (ADS)

    Kozack, R.; Madland, D. G.

    1989-04-01

    We perform a global analysis of intermediate energy nucleon plus 208Pb scattering data using the Dirac phenomenology. Proton elastic differential cross sections, analyzing powers, spin rotation functions, and total reaction cross sections, together with neutron total cross sections, spanning an incident energy range of 80-800 MeV, are used in the determination of a Dirac scalar-vector global potential. Two of six energy dependencies studied are selected to construct best-fit nucleon-nucleus potentials for the reduced incident-energy interval of 95-300 MeV. These potentials reproduce the experimental data uniformly within the reduced energy interval. Explicit values for the isovector strengths of the nucleon-nucleus potential are given. The correlations and ambiguities among the parameters of the potentials are studied. Predictions are made for the elastic differential cross section and spin observables for neutron plus 208Pb scattering.

  14. Variation of the energy release rate as a crack approaches and passes through an elastic inclusion

    NASA Technical Reports Server (NTRS)

    Li, Rongshun; Chudnovsky, A.

    1993-01-01

    The variation of the energy release rate (ERP) at the tip of a crack penetrating an elastic inclusion is analyzed using an approach involving modeling the random array of microcracks or other defects by an elastic inclusion with effective elastic properties. Computations are carried out using a finite element procedure. The eight-noded isoparametric serendipity element with the shift of the midpoint to the quarter-point is used to simulate the singularity at the crack tip, and the crack growth is accommodated by implementing a mesh regeneration technique. The ERP values were calculated for various crack tip positions which simulate the process of the crack approaching and penetrating the inclusion.

  15. Variation of the energy release rate as a crack approaches and passes through an elastic inclusion

    NASA Astrophysics Data System (ADS)

    Li, Rongshun; Chudnovsky, A.

    1993-02-01

    The variation of the energy release rate (ERP) at the tip of a crack penetrating an elastic inclusion is analyzed using an approach involving modeling the random array of microcracks or other defects by an elastic inclusion with effective elastic properties. Computations are carried out using a finite element procedure. The eight-noded isoparametric serendipity element with the shift of the midpoint to the quarter-point is used to simulate the singularity at the crack tip, and the crack growth is accommodated by implementing a mesh regeneration technique. The ERP values were calculated for various crack tip positions which simulate the process of the crack approaching and penetrating the inclusion.

  16. Structural, vibrational, and elastic properties of a calcium aluminosilicate glass from molecular dynamics simulations: the role of the potential.

    PubMed

    Bauchy, M

    2014-07-14

    We study a calcium aluminosilicate glass of composition (SiO2)0.60(Al2O3)0.10(CaO)0.30 by means of molecular dynamics. To this end, we conduct parallel simulations, following a consistent methodology, but using three different potentials. Structural and elastic properties are analyzed and compared to available experimental data. This allows assessing the respective abilities of the potentials to produce a realistic glass. We report that, although all these potentials offer a reasonable glass structure, featuring tricluster oxygen atoms, their respective vibrational and elastic predictions differ. This allows us to draw some general conclusions about the crucial role, or otherwise, of the interaction potential in silicate systems. PMID:25028027

  17. Structural, vibrational, and elastic properties of a calcium aluminosilicate glass from molecular dynamics simulations: The role of the potential

    SciTech Connect

    Bauchy, M., E-mail: bauchy@mit.edu [Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA and Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095 (United States)

    2014-07-14

    We study a calcium aluminosilicate glass of composition (SiO{sub 2}){sub 0.60}(Al{sub 2}O{sub 3}){sub 0.10}(CaO){sub 0.30} by means of molecular dynamics. To this end, we conduct parallel simulations, following a consistent methodology, but using three different potentials. Structural and elastic properties are analyzed and compared to available experimental data. This allows assessing the respective abilities of the potentials to produce a realistic glass. We report that, although all these potentials offer a reasonable glass structure, featuring tricluster oxygen atoms, their respective vibrational and elastic predictions differ. This allows us to draw some general conclusions about the crucial role, or otherwise, of the interaction potential in silicate systems.

  18. Effect of covalency, zero-point energy and charge transfer on the phase-transition, elastic and thermophysical properties of Ca-chalcogenides under compression

    Microsoft Academic Search

    D. C. Gupta; K. C. Singh

    2010-01-01

    The pressure induced phase-transition, elastic and thermophysical properties of Ca-chalcogenides have been investigated by means of many body potential. The modified charge transfer potential consists of long-range Coulomb and charge-transfer interactions modified by covalency and short-range overlap repulsion extended up to second neighbours and zero-point energy effects. Another charge-transfer model excludes covalency and zero-point energy effects. These chalcogenides undergo first-order

  19. Elastic/inelastic and charge transfer collisions of H++H2 at collision energies of 4.67, 6, 7.3, and 10 eV.

    PubMed

    Amaran, Saieswari; Kumar, Sanjay

    2008-02-14

    Quantum mechanical studies of vibrational and rotational state-resolved differential cross sections, integral cross sections, and transition probabilities for both the elastic/inelastic and charge transfer processes have been carried out at collision energies of 4.67, 6, 7.3, and 10 eV using the vibrational close-coupling rotational infinite-order sudden approach. The dynamics has been performed employing our newly obtained quasidiabatic potential energy surfaces which were generated using ab initio procedures and Dunning's correlation-consistent-polarized quadrupole zeta basis set. The present theoretical results for elastic/inelastic processes provide an overall excellent agreement with the available experimental data and they are also found to be almost similar to that obtained in earlier theoretical results using the ground electronic potential energy surface, lending credence to the accuracy and reliability of the quasidiabatic potential energy surfaces. The results for the complementary charge transfer processes are also presented at these energies. PMID:18282032

  20. Price Elasticities for Energy Use in Buildings of the United States

    EIA Publications

    2014-01-01

    Energy demand tends to be responsive to changes in energy prices, a concept in economics known as price elasticity. Generally, an increase in a fuel price causes users to use less of that fuel or switch to a different fuel. The extent to which each of these changes takes place is of high importance to stakeholders in the energy sector and especially in energy planning. The purpose of this analysis is to determine fuel-price elasticities in stationary structures, particularly in the residential and commercial sectors.

  1. NONLINEAR ELASTIC EFFECTS ON THE ENERGY FLUX DEVIATION OF ULTRASONIC WAVES IN GR\\/EP COMPOSITES

    Microsoft Academic Search

    William H. Prosser; Dale W. Fitting

    1992-01-01

    This document was created with FrameMaker 4.0.2absorption by the matrix or fiber degradation, can be detectednondestructively by measurements of the energy flux shift [6].In this research, the effects of nonlinear elasticity onenergy flux deviation in unidirectional gr\\/ep composites werestudied. Because of elastic nonlinearity, the angle of the energyflux deviation was shown to be a function of applied stress.This shift in

  2. Displacement Field and Elastic Energy of a Circular Twist Disclination for Large Deformations - an Example how to Treat Nonlinear Boundary Value Problems with Computer Algebra Systems

    Microsoft Academic Search

    Alexander Unzicker; Karl Fabian

    2003-01-01

    A circular twist disclination is a nontrivial example of a defect in an elastic continuum that causes large deformations. The minimal potential energy and the corresponding displacement field is calculated by solving the Euler-Lagrange-equations. The nonlinear incompressibility constraint is rigorously taken into account. By using an appropriate curvilinear coordinate system a finer resolution in the regions of large deformations is

  3. Theoretical modeling for neutron elastic scattering angular distribution in the fast energy range

    SciTech Connect

    Kawano, Toshihiko [Los Alamos National Laboratory

    2010-12-07

    One of the major issues of neutron scattering modeling in the fast energy range is the contribution of compound elastic and inelastic scattering to the total scattering process. The compound component may become large at very low energies where the angular distribution becomes 90-degree symmetric in the center-of-mass system. Together with the shape elastic component, the elastic scattering gives slightly forward-peaked angular distributions in the fast energy range. This anisotropic angular distribution gives high sensitivities to many important nuclear reactor characteristics, such as criticality and neutron shielding. In this talk we describe how the anisotropic angular distributions are calculated within the statistical model framework, including the case where strongly coupled channels exist, by combining the coupled-channels theory with the Hauser-Feshbach model. This unique capability extension will have significant advantages in understanding the neutron scattering process for deformed nuclei, like uranium or plutonium, on which advanced nuclear energy applications center.

  4. Regulation of residual stress in elastic solid component with high-energy acoustic field

    NASA Astrophysics Data System (ADS)

    Song, W. T.; Xu, C. G.; Pan, Q. X.; Yang, X. C.; Xu, L.; Guo, J.

    2013-01-01

    The ultrasonic regulation of internal residual stress in metal and nonmetal elastic solid component has been investigated. High-energy ultrasonic wave is applied to carbon steel and ordinary flat glass for residual stress control. An ultrasonic residual stress measurement device developed with the acoustoelastic theory is used to measure macro residual stress in time, to evaluate the residual stress regulation effectiveness. Based on the essence of residual stress, the interaction between acoustic wave and residual stress is analyzed, and dislocations theory is considered. When the ultrasonic energy supplied to the elastic solid is greater than the energy of dislocation, the internal residual stress will be released. Experiments result shows that as high energy acoustic field is applied, the local residual tensile stress in elastic solid specimen will shift gradually to beneficial compressive stress, thus the component's fatigue strength, corrosion resistance and service life will be greatly improved.

  5. Spectral Modeling of Residual Stress and Stored Elastic Strain Energy in Thermal Barrier Coatings

    SciTech Connect

    Donegan, Sean; Rolett, Anthony

    2013-12-31

    Solutions to the thermoelastic problem are important for characterizing the response under temperature change of refractory systems. This work extends a spectral fast Fourier transform (FFT) technique to analyze the thermoelastic behavior of thermal barrier coatings (TBCs), with the intent of probing the local origins of failure in TBCs. The thermoelastic FFT (teFFT) approach allows for the characterization of local thermal residual stress and strain fields, which constitute the origins of failure in TBC systems. A technique based on statistical extreme value theory known as peaks-over-threshold (POT) is developed to quantify the extreme values ("hot spots") of stored elastic strain energy (i.e., elastic energy density, or EED). The resolution dependence of the teFFT method is assessed through a sensitivity study of the extreme values in EED. The sensitivity study is performed both for the local (point-by-point) #12;eld distributions as well as the grain scale #12;eld distributions. A convergence behavior to a particular distribution shape is demonstrated for the local #12;elds. The grain scale fields are shown to exhibit a possible convergence to a maximum level of EED. To apply the teFFT method to TBC systems, 3D synthetic microstructures are created to approximate actual TBC microstructures. The morphology of the grains in each constituent layer as well as the texture is controlled. A variety of TBC materials, including industry standard materials and potential future materials, are analyzed using the teFFT. The resulting hot spots are quantified using the POT approach. A correlation between hot spots in EED and interface rumpling between constituent layers is demonstrated, particularly for the interface between the bond coat (BC) and the thermally grown oxide (TGO) layer.

  6. Photoelectron energy spectra from elastic rescattering in ultrastrong laser fields: A relativistic extension of the three-step model

    NASA Astrophysics Data System (ADS)

    Luo, S. S.; Grugan, P. D.; Walker, B. C.

    2015-03-01

    Using a relativistic adaptation of a three-step recollision model we calculate photoelectron energy spectra for ionization with elastic scattering in ultrastrong laser fields up to 24 a.u. (2 ×1019 W/cm 2) . Hydrogenlike and noble gas species with Hartree-Fock scattering potentials show a reduction in elastic rescattering beyond 6 ×1016 W/cm 2 when the laser Lorentz deflection of the photoelectron exceeds its wave-function spread. A relativistic rescattering enhancement occurs at 2 ×1018 W/cm 2, commensurate with the relativistic motion of a classical electron in a single field cycle. The noble gas results are compared with available experiments. The theory approach is well suited to modeling scattering in the ultrastrong intensity regime that lies between traditional strong fields and extreme relativistic interactions.

  7. The series elastic shock absorber: tendon elasticity modulates energy dissipation by muscle during burst deceleration.

    PubMed

    Konow, Nicolai; Roberts, Thomas J

    2015-04-01

    During downhill running, manoeuvring, negotiation of obstacles and landings from a jump, mechanical energy is dissipated via active lengthening of limb muscles. Tendon compliance provides a 'shock-absorber' mechanism that rapidly absorbs mechanical energy and releases it more slowly as the recoil of the tendon does work to stretch muscle fascicles. By lowering the rate of muscular energy dissipation, tendon compliance likely reduces the risk of muscle injury that can result from rapid and forceful muscle lengthening. Here, we examine how muscle-tendon mechanics are modulated in response to changes in demand for energy dissipation. We measured lateral gastrocnemius (LG) muscle activity, force and fascicle length, as well as leg joint kinematics and ground-reaction force, as turkeys performed drop-landings from three heights (0.5-1.5 m centre-of-mass elevation). Negative work by the LG muscle-tendon unit during landing increased with drop height, mainly owing to greater muscle recruitment and force as drop height increased. Although muscle strain did not increase with landing height, ankle flexion increased owing to increased tendon strain at higher muscle forces. Measurements of the length-tension relationship of the muscle indicated that the muscle reached peak force at shorter and likely safer operating lengths as drop height increased. Our results indicate that tendon compliance is important to the modulation of energy dissipation by active muscle with changes in demand and may provide a mechanism for rapid adjustment of function during deceleration tasks of unpredictable intensity. PMID:25716796

  8. Tough and elastic hydrogel of hyaluronic acid and chondroitin sulfate as potential cell scaffold materials.

    PubMed

    Ni, Yilu; Tang, Zhurong; Cao, Wanxu; Lin, Hai; Fan, Yujiang; Guo, Likun; Zhang, Xingdong

    2015-03-01

    Natural polysaccharides are extensively investigated as cell scaffold materials for cellular adhesion, proliferation, and differentiation due to their excellent biocompatibility, biodegradability, and biofunctions. However, their application is often severely limited by their mechanical behavior. In this study, a tough and elastic hydrogel scaffold was prepared with hyaluronic acid (HA) and chondroitin sulfate (CS). HA and CS were conjugated with tyramine (TA) and the degree of substitution (DS) was 10.7% and 11.3%, respectively, as calculated by (1)H NMR spectra. The hydrogel was prepared by mixing HA-TA and CS-TA in presence of H2O2 and HRP. The sectional morphology of hydrogels was observed by SEM, static and dynamic mechanical properties were analyzed by Shimadzu electromechanical testing machine and dynamic mechanical thermal analyzer Q800. All samples showed good ability to recover their appearances after deformation, the storage modulus (E') of hydrogels became higher as the testing frequency went up. Hydrogels also showed fatigue resistance to cyclic compression. Mesenchymal stem cells encapsulated in hydrogels showed good cell viability as detected by CLSM. This study suggests that the hydrogels have both good mechanical properties and biocompatibility, and may serve as model systems to explore mechanisms of deformation and energy dissipation or find some applications in tissue engineering. PMID:25445680

  9. Momentum-energy change in elastic relativistic binary collisions

    NASA Astrophysics Data System (ADS)

    Menon, V. J.; Dubey, R. K.; Mishra, M.; Patra, B. K.

    2009-05-01

    We consider a relativistic elastic collision between a projectile of momentum p with a target atom of momentum k in a general inertial frame. We employ one space plus one time Minkowski geometry and calculate the momentum transfer vector q? suffered by the projectile calculated via a Lorentz transformation to the barycentric frame and then eliminate k. The resulting expression for q? reproduces several known cases, its algebraic behavior can be interpreted physically, and it leads to a simple understanding of the relativistic equipartition law.

  10. Impact picture for near-forward elastic scattering up to LHC energies

    E-print Network

    Jacques Soffer; Claude Bourrely; Tai Tsun Wu

    2014-12-02

    We will recall the main feaatures of an accurate phenomenological model to describe successfully near-forward elastic scattering in a wide energy range, including ISR, SPS and Tevatron colliders. A large step in energy domain is accomplished with the LHC collider, presently running, giving the opportunity to confront the new data with the predictions of our theoretical approach.

  11. Impact picture for near-forward elastic scattering up to LHC energies

    NASA Astrophysics Data System (ADS)

    Soffer, Jacques; Bourrely, Claude; Wu, Tai Tsun

    2015-04-01

    We will recall the main features of an accurate phenomenological model to describe successfully near-forward elastic scattering in a wide energy range, including ISR, SPS and Tevatron colliders. A large step in energy domain is accomplished with the LHC collider, presently running, giving the opportunity to confront the new data with the predictions of our theoretical approach.

  12. Wind energy and assessment of wind energy potential in Turkey

    Microsoft Academic Search

    2012-01-01

    In this study, the potential of wind energy and assessment of wind energy systems in Turkey were studied. The main purpose of this study is to investigate the wind energy potential and future wind conversion systems project in Turkey. The wind energy potential of various regions was investigated; and the exploitation of the wind energy in Turkey was discussed. Various

  13. Renewable Energy Potential for Brownfield Redevelopment Strategies

    E-print Network

    Renewable Energy Potential for Brownfield Redevelopment Strategies Renewable energy resources are available throughout the United States.The National Renewable Energy Laboratory (NREL) performs analysis to identify high-potential sites for renewable energy technologies and can help determine those technologies

  14. The elastic free energy of a tandem modular protein under force.

    PubMed

    Valle-Orero, Jessica; Eckels, Edward C; Stirnemann, Guillaume; Popa, Ionel; Berkovich, Ronen; Fernandez, Julio M

    2015-05-01

    Recent studies have provided a theoretical framework for including entropic elasticity in the free energy landscape of proteins under mechanical force. Accounting for entropic elasticity using polymer physics models has helped explain the hopping behavior seen in single molecule experiments in the low force regime. Here, we expand on the construction of the free energy of a single protein domain under force proposed by Berkovich et al. to provide a free energy landscape for N tandem domains along a continuous polypeptide. Calculation of the free energy of individual domains followed by their concatenation provides a continuous free energy landscape whose curvature is dominated by the worm-like chain at forces below 20 pN. We have validated our free energy model using Brownian dynamics and reproduce key features of protein folding. This free energy model can predict the effects of changes in the elastic properties of a multidomain protein as a consequence of biological modifications such as phosphorylation or the formation of disulfide bonds. This work lays the foundations for the modeling of tissue elasticity, which is largely determined by the properties of tandem polyproteins. PMID:25796331

  15. Nonlinear Elastic Effects on the Energy Flux Deviation of Ultrasonic Waves in GR/EP Composites

    NASA Technical Reports Server (NTRS)

    Prosser, William H.; Kriz, R. D.; Fitting, Dale W.

    1992-01-01

    In isotropic materials, the direction of the energy flux (energy per unit time per unit area) of an ultrasonic plane wave is always along the same direction as the normal to the wave front. In anisotropic materials, however, this is true only along symmetry directions. Along other directions, the energy flux of the wave deviates from the intended direction of propagation. This phenomenon is known as energy flux deviation and is illustrated. The direction of the energy flux is dependent on the elastic coefficients of the material. This effect has been demonstrated in many anisotropic crystalline materials. In transparent quartz crystals, Schlieren photographs have been obtained which allow visualization of the ultrasonic waves and the energy flux deviation. The energy flux deviation in graphite/epoxy (gr/ep) composite materials can be quite large because of their high anisotropy. The flux deviation angle has been calculated for unidirectional gr/ep composites as a function of both fiber orientation and fiber volume content. Experimental measurements have also been made in unidirectional composites. It has been further demonstrated that changes in composite materials which alter the elastic properties such as moisture absorption by the matrix or fiber degradation, can be detected nondestructively by measurements of the energy flux shift. In this research, the effects of nonlinear elasticity on energy flux deviation in unidirectional gr/ep composites were studied. Because of elastic nonlinearity, the angle of the energy flux deviation was shown to be a function of applied stress. This shift in flux deviation was modeled using acoustoelastic theory and the previously measured second and third order elastic stiffness coefficients for T300/5208 gr/ep. Two conditions of applied uniaxial stress were considered. In the first case, the direction of applied uniaxial stress was along the fiber axis (x3) while in the second case it was perpendicular to the fiber axis along the laminate stacking direction (x1).

  16. Potential of geothermal energy in China

    E-print Network

    Sung, Peter On

    2010-01-01

    This thesis provides an overview of geothermal power generation and the potential for geothermal energy utilization in China. Geothermal energy is thermal energy stored in the earth's crust and currently the only ubiquitously ...

  17. The elastodynamic Liénard-Wiechert potentials and elastic fields of non-uniformly moving point and line forces

    E-print Network

    Markus Lazar

    2012-05-23

    The purpose of this paper is to investigate the fundamental problem of the non-uniform subsonic motion of a point force and line forces in an unbounded, homogeneous, isotropic medium in analogy to the electromagnetic Li\\'enard-Wiechert potentials. The exact closed-form solutions of the displacement and elastic fields produced by the point force and line forces are calculated. The displacement fields can be identified with the elastodynamic Li\\'enard-Wiechert tensor potentials. For a non-uniformly moving point force, we decompose the elastic fields into a radiation part and a non-radiation part. We show that the solution of a non-uniformly moving point force is the generalization of the Stokes solution towards the non-uniform motion. For line forces the mathematical solutions are given in the form of time-integrals and, therefore, their motion depends on the history.

  18. Ab-initio calculation on elastic scattering of low energy electrons by sulfur atoms

    SciTech Connect

    Hari P.S.; Dong Lin [Univ. of Central Florida, Orlando, FL (United States)

    1996-05-01

    Accurate ab-initio calculation of scattering length, total and Momentum-transfer cross sections is performed for low-energy elastic scattering of electrons from open-shell sulfur atom. The polarization of the sulfur atoms due to the scattered electron and the electron correlation effects that are very important in the calculation are taken into account through the configuration interaction procedure using the multiconfiguration Hartree-Fock method for electron-atom scattering. The elastic differential, total elastic and momentum-transfer cross sections for low energies ranging from 0 - 27.2 eV are obtained from phase shifts for various partial waves calculated in this approximation. The present results will be compared with the available experimental and other theoretical results.

  19. Differential elastic scattering of Ne*(3s /sup 3/P/sub 2,0/) by Ar, Kr, and Xe: Optical potentials and their orbital interpretation

    SciTech Connect

    Gregor, R.W.; Siska, P.E.

    1981-01-15

    Optical potentials for the title systems have been derived by simultaneous fitting of thermal-energy elastic scattering angular distributions reported here and ionization cross section and quenching rate constant data from other laboratories. The real parts of these potentials are similar to sodium--rare gas van der Waals potentials, with well depths epsilon=0.126 kcal/mole for Ne*+Ar, 0.192 kcal/mole for Kr, and 0.288 kcal/mole for Xe, with r/sub m/=5.0 A for all three systems. A direct inversion of Ne*+Xe rainbow scattering yields a potential in good accord with the parametric form used in fitting. One-electron model potential calculations also produce curves in good agreement with experiment, and shed light on the effect of orbital mixing (hybridization of the Ne*3s orbital) on the shape of the repulsive branch of the potentials. The derived resonance widths GAMMA (imaginary parts of the optical potentials) give evidence that a Coulomb or radiative mechanism dominates the thermal-energy quenching by Penning ionization, in contrast to the exchange mechanism thought to be dominant for He*(2 /sup 1/S,2 /sup 3/S). The neon 3d orbital, mixed into the excited electron's orbital by exchange repulsion, appears to play a key role in this mechanistic changeover.

  20. Energy dependence of nucleon-nucleon potentials

    E-print Network

    Sinya Aoki; Janos Balog; Tetsuo Hatsuda; Noriyoshi Ishii; Keiko Murano; Hidekatsu Nemura; Peter Weisz

    2008-12-03

    We investigate the energy dependence of potentials defined through the Bethe-Salpeter wave functions. We analytically evaluate such a potential in the Ising field theory in 2 dimensions and show that its energy dependence is weak at low energy. We then numerically calculate the nucleon-nucleon potential at non-zero energy using quenched QCD with anti-periodic boundary condition. In this case we also observe that the potentials are almost identical at $E\\simeq 0$ and $E\\simeq 50$ MeV, where $E$ is the center of mass kinetic energy.

  1. High energy proton-proton elastic scattering at the Large Hadron Collider and nucleon structure

    NASA Astrophysics Data System (ADS)

    Luddy, Richard Joseph

    To gain insight into the structure of the nucleon, we pursue the development of the phenomenological model of Islam et al. (IIFS model) for high energy elastic pp and p¯p scattering. We determine the energy dependence of the parameters of the IIFS model using the available elastic differential cross section data from SPS Collider and Tevatron and the known asymptotic behavior of sigmatot (s) and rho(s) from dispersion relation calculations and more recent analyses of Cudell et al. (COMPETE Collaboration). Next, we incorporate a high energy elastic valence quark-quark scattering amplitude into the model based on BFKL pomeron to describe small impact parameter (large | t|) pp collisions. Finally, we predict the pp elastic differential cross section at the unprecedented c.m. energy of s = 14.0 TeV at the Large Hadron Collider (LHC). This prediction assumes crucial significance---because of an approved experiment at LHC: TOTal and Elastic Measurement (TOTEM). The TOTEM group plans to measure pp elastic dsigma/dt at 14.0 TeV all the way from momentum transfer |t| = 0 to |t| ? 10 GeV 2. Their measurement will stringently test not only the diffraction and o-exchange descriptions of the original IIFS model, but also the additional valence quark-quark scattering contribution that we find to be dominant for large |t|. Successful quantitative verification of the predicted dsigma/dt will mean that our picture of the nucleon with an outer cloud of qq¯ condensed ground state, an inner core of topological baryonic charge, and a still smaller core of massless valence quarks provides a realistic description of nucleon structure.

  2. Energy current imaging method for time reversal in elastic media

    SciTech Connect

    Anderson, Brian E [Los Alamos National Laboratory; Ulrich, Timothy J [Los Alamos National Laboratory; Le Bas, Pierre - Yves A [Los Alamos National Laboratory; Larmat, Carene [Los Alamos National Laboratory; Johnson, Paul A [Los Alamos National Laboratory; Guyer, Robert A [UNR; Griffa, Michele [ETH ZURICH

    2009-01-01

    An energy current imaging method is presented for use in locating sources of wave energy during the back propagation stage of the time reversal process. During the back propagation phase of an ideal time reversal experiment, wave energy coalesces from all angles of incidence to recreate the source event; after the recreation, wave energy diverges in every direction. An energy current imaging method based on this convergence/divergence behavior has been developed. The energy current imaging method yields a smaller spatial distribution for source reconstruction than is possible with traditional energy imaging methods.

  3. Biomass energy potential in Turkey

    Microsoft Academic Search

    K. Kaygusuz; M. F. Türker

    2002-01-01

    Biomass energy includes fuelwood, agricultural residues, animal wastes, charcoal and other fuels derived from biological sources. It currently accounts for about 14% of world energy consumption. Biomass is the main source of energy for many developed and developing countries. In Turkey energy wood is available in the form of forest chips, fuelwood, wood waste, wood pellets, and it is also

  4. Geothermal Energy: Tapping the Potential

    ERIC Educational Resources Information Center

    Johnson, Bill

    2008-01-01

    Ground source geothermal energy enables one to tap into the earth's stored renewable energy for heating and cooling facilities. Proper application of ground-source geothermal technology can have a dramatic impact on the efficiency and financial performance of building energy utilization (30%+). At the same time, using this alternative energy…

  5. Validity of the relativistic impulse approximation for elastic proton-nucleus scattering at energies lower than 200 MeV

    SciTech Connect

    Li, Z. P. [School of Physics, Peking University, Beijing 100871 (China); Hillhouse, G. C. [School of Physics, Peking University, Beijing 100871 (China); Department of Physics, University of Stellenbosch, Stellenbosch (South Africa); Meng, J. [School of Physics, Peking University, Beijing 100871 (China); Department of Physics, University of Stellenbosch, Stellenbosch (South Africa); Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100080 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China)

    2008-07-15

    We present the first study to examine the validity of the relativistic impulse approximation (RIA) for describing elastic proton-nucleus scattering at incident laboratory kinetic energies lower than 200 MeV. For simplicity we choose a {sup 208}Pb target, which is a spin-saturated spherical nucleus for which reliable nuclear structure models exist. Microscopic scalar and vector optical potentials are generated by folding invariant scalar and vector scattering nucleon-nucleon (NN) amplitudes, based on our recently developed relativistic meson-exchange model, with Lorentz scalar and vector densities resulting from the accurately calibrated PK1 relativistic mean field model of nuclear structure. It is seen that phenomenological Pauli blocking (PB) effects and density-dependent corrections to {sigma}N and {omega}N meson-nucleon coupling constants modify the RIA microscopic scalar and vector optical potentials so as to provide a consistent and quantitative description of all elastic scattering observables, namely, total reaction cross sections, differential cross sections, analyzing powers and spin rotation functions. In particular, the effect of PB becomes more significant at energies lower than 200 MeV, whereas phenomenological density-dependent corrections to the NN interaction also play an increasingly important role at energies lower than 100 MeV.

  6. Validity of the relativistic impulse approximation for elastic proton-nucleus scattering at energies lower than 200 MeV

    NASA Astrophysics Data System (ADS)

    Li, Z. P.; Hillhouse, G. C.; Meng, J.

    2008-07-01

    We present the first study to examine the validity of the relativistic impulse approximation (RIA) for describing elastic proton-nucleus scattering at incident laboratory kinetic energies lower than 200 MeV. For simplicity we choose a Pb208 target, which is a spin-saturated spherical nucleus for which reliable nuclear structure models exist. Microscopic scalar and vector optical potentials are generated by folding invariant scalar and vector scattering nucleon-nucleon (NN) amplitudes, based on our recently developed relativistic meson-exchange model, with Lorentz scalar and vector densities resulting from the accurately calibrated PK1 relativistic mean field model of nuclear structure. It is seen that phenomenological Pauli blocking (PB) effects and density-dependent corrections to ?N and ?N meson-nucleon coupling constants modify the RIA microscopic scalar and vector optical potentials so as to provide a consistent and quantitative description of all elastic scattering observables, namely, total reaction cross sections, differential cross sections, analyzing powers and spin rotation functions. In particular, the effect of PB becomes more significant at energies lower than 200 MeV, whereas phenomenological density-dependent corrections to the NN interaction also play an increasingly important role at energies lower than 100 MeV.

  7. Validity of the relativistic impulse approximation for elastic proton-nucleus scattering at energies lower than 200 MeV

    E-print Network

    Z. P. Li; G. C. Hillhouse; J. Meng

    2008-06-16

    We present the first study to examine the validity of the relativistic impulse approximation (RIA) for describing elastic proton-nucleus scattering at incident laboratory kinetic energies lower than 200 MeV. For simplicity we choose a $^{208}$Pb target, which is a spin-saturated spherical nucleus for which reliable nuclear structure models exist. Microscopic scalar and vector optical potentials are generated by folding invariant scalar and vector scattering nucleon-nucleon (NN) amplitudes, based on our recently developed relativistic meson-exchange model, with Lorentz scalar and vector densities resulting from the accurately calibrated PK1 relativistic mean field model of nuclear structure. It is seen that phenomenological Pauli blocking (PB) effects and density-dependent corrections to $\\sigma$N and $\\omega$N meson-nucleon coupling constants modify the RIA microscopic scalar and vector optical potentials so as to provide a consistent and quantitative description of all elastic scattering observables, namely total reaction cross sections, differential cross sections, analyzing powers and spin rotation functions. In particular, the effect of PB becomes more significant at energies lower than 200 MeV, whereas phenomenological density-dependent corrections to the NN interaction {\\it also} play an increasingly important role at energies lower than 100 MeV.

  8. Non-resonant elastic scattering of low-energy photons by atomic sodium confined in quantum plasmas

    NASA Astrophysics Data System (ADS)

    Ghosh, Avijit; Ray, Debasis

    2015-03-01

    The non-resonant elastic scattering of low-energy photons by the bound valence electron in the ground state 3s of atomic sodium confined in quantum plasmas is investigated theoretically. The incident photon energy is assumed to be much smaller than the 3s-3p excitation energy. The alkali atom sodium is first formulated as an effective one-electron problem in which the attractive interaction between the valence electron and the atomic ion core is simulated by a spherically symmetric model potential. The Shukla-Eliasson oscillatory exponential cosine screened-Coulomb potential model is then used to mimic the effective two-body (valence-core) interaction within quantum plasmas. Non-relativistic calculations performed within the electric dipole approximation indicate that the non-resonant elastic photon scattering cross-section undergoes a dramatic growth by several orders of magnitude as the quantum wave number increases. A qualitative explanation of this phenomenon is presented. In the absence of the oscillatory cosine screening term, a similar growth is observed at larger values of the quantum wave number. Our computed relevant atomic data are in very good agreement with the experimental as well as the previous theoretical data for the zero-screening (free atom) case, and with the very limited, accurate theoretical results available for the case of exponential screened-Coulomb two-body interaction, without the cosine screening term.

  9. Modified-surface-energy methods for deriving heavy-ion potentials

    Microsoft Academic Search

    Sierk

    1977-01-01

    The use of a modified-surface-energy approach for the calculation of heavy-ion interaction potentials is discussed. It is not possible to simultaneously fit elastic scattering, ion interaction barriers, and fission barriers with the same set of constants in this model. Possible explanations of this deficiency are discussed.

  10. Coda wave interferometry and the equilibration of energy in elastic media Roel Snieder

    E-print Network

    Snieder, Roel

    Coda wave interferometry and the equilibration of energy in elastic media Roel Snieder Department of Geophysics and Center for Wave Phenomena, Colorado School of Mines, Golden, Colorado 80401 Received 14 May 2002; published 21 October 2002 Multiple-scattered waves usually are not useful for creating

  11. Elastic, excitation, ionization and charge transfer cross sections of current interest in fusion energy research

    SciTech Connect

    Schultz, D.R.; Krstic, P.S.

    1996-12-31

    Due to the present interest in modeling and diagnosing the edge and divertor plasma regions in magnetically confined fusion devices, we have sought to provide new calculations regarding the elastic, excitation, ionization, and charge transfer cross sections in collisions among relevant ions, neutrals, and isotopes in the low- to intermediate-energy regime. We summarize here some of our recent work.

  12. Study of dp-elastic scattering at energies 650, 750 and 1000 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Terekhin, A. A.; Ladygin, V. P.; Piyadin, S. M.; Gurchin, Yu. V.; Resnikov, S. G.; Isupov, A. Yu.; Kurilkin, P. K.; Kurilkin, A. K.; Khrenov, A. N.; Vnukov, I. E.

    2013-12-01

    The results of measurements of dp-elastic scattering at 650, 750 and 1000 MeV/nucleon at Nuclotron JINR are reported. The data have been obtained for angels range of 75-120 deg. in the c.m.s. The results are compared with existing data for corresponding values of energies.

  13. Transportation Energy Futures Series: Potential for Energy Efficiency...

    National Renewable Energy Laboratory (NREL)

    energy-intensity improvement potential in the aviation sector, as derived from this literature search. Table 3.1. Summary of Aviation Energy-Intensity Improvement Potential...

  14. Effect of anchoring energy and elastic anisotropy on spherical inclusions in a nematic liquid crystal.

    PubMed

    James, Richard; Fukuda, Jun-ichi

    2013-07-01

    This paper explores how pairs of spherical particles with homeotropic (normal) surface anchoring cluster when immersed in nematic liquid crystal. By means of the Landau-de Gennes continuum theory we calculate how the equilibrium separation of a particle pair depends on the anchoring energy at the particle surface and the elastic anisotropy of the liquid crystal. We find that, for modest to strong anchoring strengths, the particle separation depends linearly on the elastic anisotropy and the inverse of the anchoring strength. Thus, the anchoring strength can be estimated by measuring the particle-pair separation. PMID:23944394

  15. Energy dissipation in heavy systems: the transition from quasi-elastic to deep-inelastic scattering

    SciTech Connect

    Rehm, K.E.; van den Berg, A.; Kolata, J.J.; Kovar, D.G.; Kutschera, W.; Rosner, G.; Stephans, G.S.F.; Yntema, J.L.; Lee, L.L.

    1984-01-01

    The interaction of medium mass projectiles (A = 28 - 64) with /sup 208/Pb has been studied using a split-pole spectrograph which allows single mass and charge identification. The reaction process in all systems studied so far is dominated by quasi-elastic neutron transfer reactions, especially at incident energies in the vicinity of the Coulomb barrier. In addition to the quasi-elastic component deep inelastic contributions are present in all reaction channels. The good mass and charge separation allows to generate Wilczynski plots for individual channels; for the system /sup 48/Ti + /sup 208/Pb we observe that the transition between the quasi-elastic and deep-inelastic reactions occurs around Q = -(30 to 35) MeV.

  16. Potential Energy Total electric potential energy, U, of a system of

    E-print Network

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    due to q1 is Bring q2 in from infinity. From definition of potential energy or Charges of like sign, WPotential Energy Total electric potential energy, U, of a system of charges is obtained from of work done by the field, W*= -W. Bring q1 from , W *= 0 since no electric F yet #12;Potential Energy

  17. Potential Energy Total electric potential energy, U, of a system of

    E-print Network

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    is Bring q2 in from infinity. From definition of potential energy or Charges of like sign, W * and UPotential Energy Total electric potential energy, U, of a system of charges is obtained from of work done by the field, W*= -W. Bring q1 from , W *= 0 since no electric F yet #12;Potential Energy

  18. Savings energy through electricity: The technological potential

    SciTech Connect

    Gellings, C.W.; Yau, T.S. [Electric Power Research Institute, Palo Alto, CA (United States)

    1991-12-31

    This article explores probably energy savings and the corresponding reductions in carbon dioxide by the year 2000. In addition, energy savings in a longer time are examined. For the longer time frame it would be possible to achieve further energy savings through increased electrification and additional electric energy efficiency improvements. Both the maximum technical potential for efficiency savings and then the role of electrification and potential technological advancements are examined. Topics include the following: efficiency improvements attributable to regulatory mandates and natural market mechanisms; efficiency improvements attributable to utility demand side management programs; maximum technical potential efficiency improvements; electrification, the forgotten path to energy savings.

  19. Prediction of Dyke Propagation using the Minimum Potential Energy Principle

    NASA Astrophysics Data System (ADS)

    Heimisson, Elías; Hooper, Andrew; Sigmundsson, Freysteinn

    2015-04-01

    An important aspect of eruption forecasting is the prediction and monitoring of dyke propagation. Eruptions occur where dykes propagate to the surface, with lava flows causing a major threat. When such eruption occur under ice, as is common in Iceland, they become explosive and often cause hazardous and destructive floods. Dykes have also been known to trigger explosive eruption when hot basaltic magma comes in contact with more developed volatile saturated magma. Such explosive eruptions pose a danger to both lives and property. At divergent plate boundaries new crust is formed primarily by dyke injections. These injections usually grow laterally away from a central volcano. Lateral growth of a dyke is expected to follow the minimum potential energy principle. Assuming a closed system, a dyke will tend to be emplaced such that it minimizes the total potential energy, ?T, given by: ?T = ?s + ?g (1) where ?s is the strain potential and ?g the gravitational energy potential. Assuming that the elastic medium behaves linearly the strain potential can be calculated by numerically integrating the strain energy density over a large volume. If the dyke is assumed to be propagating at a constant depth with respect to sea level the gravitational potential energy can be turned into a two dimensional integral. We do this by integrating the predicted vertical displacements multiplied by the local topographic load above a reference surface and the acceleration of gravity. We approximate strain and stress due to plate movements and then consider strain changes induced by the dyke formation. Opening of a dyke is energetically favourable when it releases strain energy built up at a divergent plate boundary, but once deviatoric stress in the crust adjacent to a segment is released it becomes favourable to propagate laterally. Dyke formation is associated with uplift on their flanks; the lower the topographic load over the flanks, the less energy it costs. For any given location on a volcano, the strike of a new dyke segment will influence the strain and gravitational potential energy change in a different way. This type of model was applied to the more than 45 km long dyke formed in the Bárðarbunga volcanic system in Iceland in a rifting event in August 2014. Large observed changes in strike can be explained mostly by interplay of gravitational effects of topography and plate boundary strain. The model minimizing the total potential energy explains this propagation path. Our results suggest that by applying the total minimum potential energy principle we can forecast dyke propagation.

  20. Importance of the energy-dependent geometry in the /sup 16/O+ /sup 16/O optical model potential

    SciTech Connect

    Pantis, G.; Ioannidis, K.; Poirier, P.

    1985-08-01

    Optical model potentials with various forms of energy-dependent geometry have been considered for the description of /sup 16/O+ /sup 16/O elastic scattering. It is shown that the variation with energy of the imaginary radius leads to a reasonable fit of the cross-section data, throughout the energy range.

  1. {ital Ab initio} calculation for low-energy elastic scattering of electrons from sulfur atoms

    SciTech Connect

    Saha, H.P.; Lin, D. [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States)] [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States)

    1997-09-01

    The multiconfiguration Hartree-Fock method for continuum wave functions has been used to perform calculations of elastic scattering of electrons from the open-shell sulfur atom at low energies. The electron correlation and polarization of the sulfur atom by the scattered electron, which are very important in this calculation, have been taken into account very accurately {ital ab initio} through the configuration-interaction procedure by optimizing both bound and continuum orbitals simultaneously at each kinetic energy of the scattered electron. The scattering lengths, phase shifts, and differential, total and momentum-transfer cross sections for electrons elastically scattered from sulfur atoms are calculated for the impact-energy range from 0 to 27.2 eV. The wave functions computed exactly at zero energy are used to compute the scattering length. The present results are compared with other available theoretical results. {copyright} {ital 1997} {ital The American Physical Society}

  2. Three nucleon force effects in intermediate-energy deuteron analyzing powers for dp elastic scattering

    SciTech Connect

    Sekiguchi, K. [Department of Physics, Tohoku University, Sendai, 980-8578 (Japan); Okamura, H. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka, 567-0047 (Japan); Sakamoto, N.; Sakaguchi, S.; Sasano, M. [RIKEN Nishina Center, Wako, 351-0198 (Japan); Suzuki, H. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, 305-8571 (Japan); Dozono, M.; Wakasa, T. [Department of Physics, Kyushu University, Fukuoka, 812-8581 (Japan); Maeda, Y.; Saito, T. [Faculty of Engineering, University of Miyazaki, Miyazaki, 889-2192 (Japan); Sakai, H. [RIKEN Nishina Center, Wako, 351-0198 (Japan); Department of Physics, University of Tokyo, Tokyo, 113-0033 (Japan); Shimizu, Y. [Center for Nuclear Study, University of Tokyo, Tokyo, 113-0033 (Japan); Yako, K. [Department of Physics, University of Tokyo, Tokyo, 113-0033 (Japan); Witala, H.; Golak, J. [Institute of Physics, Jagiellonian University, PL-30059 Cracow (Poland); Gloeckle, W. [Institut fuer theoretische Physik II, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Kamada, H. [Department of Physics, Kyushu Institute of Technology, Kitakyushu 804-8550 (Japan); Nogga, A. [Institut fuer Kernphysik, Institute for Advanced Simulation and Juelich Center for Hadron Physics, D-52428 Juelich (Germany)

    2011-06-15

    A complete high precision set of deuteron analyzing powers for elastic deuteron-proton (dp) scattering at 250 MeV/nucleon (MeV/N) has been measured. The new data are presented together with data from previous measurements at 70, 100, 135 and 200 MeV/N. They are compared with the results of three-nucleon (3N) Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three nucleon forces (3NFs): the Tucson-Melbourne 99 (TM99) and Urbana IX. At 250 MeV/N large discrepancies between pure NN models and data, which are not resolved by including 3NFs, were found at c.m. backward angles of {theta}{sub c.m.} > or approx. 120 deg. for almost all the deuteron analyzing powers. These discrepancies are quite similar to those found for the cross section at the same energy. We found small relativistic effects that cannot resolve the discrepancies with the data indicating that other, short-ranged 3NFs are required to obtain a proper description of the data.

  3. Elastic Scattering of Low-Energy Pions and Muons from Lead

    Microsoft Academic Search

    G. Dugan; S. Childress; L. M. Lederman; L. E. Price; T. Sanford

    1973-01-01

    The small-angle (13°-40°) part of the elastic differential cross section for the scattering of low-energy (Tpi~100 MeV) positive and negative pions from natural lead was measured. The same quantity was also measured for the scattering of low-energy muons from lead. The muon-lead data were used to determine the rms charge radius of the lead nucleus. Assuming a Fermi shape for

  4. Potential Water and Energy Savings from Showerheads

    SciTech Connect

    Biermayer, Peter J.

    2005-09-28

    This paper estimates the benefits and costs of six water reduction scenarios. Benefits and costs of showerhead scenarios are ranked in this paper by an estimated water reduction percentage. To prioritize potential water and energy saving scenarios regarding showerheads, six scenarios were analyzed for their potential water and energy savings and the associated dollar savings to the consumer.

  5. Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities

    E-print Network

    Management, Simon Fraser University; Senior Managing Partner at Navius Research Inc. Date Defended consumption between technologically frozen and `business as usual' simulations. The paper concludes with some; autonomous energy efficiency index; rebound effect; fuel switching. #12;iv Acknowledgements Thanks

  6. EMTA’s Evaluation of the Elastic Properties for Fiber Polymer Composites Potentially Used in Hydropower Systems

    SciTech Connect

    Nguyen, Ba Nghiep; Paquette, Joshua

    2010-08-01

    Fiber-reinforced polymer composites can offer important advantages over metals where lightweight, cost-effective manufacturing and high mechanical performance can be achieved. To date, these materials have not been used in hydropower systems. In view of the possibility to tailor their mechanical properties to specific applications, they now have become a subject of research for potential use in hydropower systems. The first step in any structural design that uses composite materials consists of evaluating the basic composite mechanical properties as a function of the as-formed composite microstructure. These basic properties are the elastic stiffness, stress-strain response, and strength. This report describes the evaluation of the elastic stiffness for a series of common discontinuous fiber polymer composites processed by injection molding and compression molding in order to preliminarily estimate whether these composites could be used in hydropower systems for load-carrying components such as turbine blades. To this end, the EMTA (Copyright © Battelle 2010) predictive modeling tool developed at the Pacific Northwest National Laboratory (PNNL) has been applied to predict the elastic properties of these composites as a function of three key microstructural parameters: fiber volume fraction, fiber orientation distribution, and fiber length distribution. These parameters strongly control the composite mechanical performance and can be tailored to achieve property enhancement. EMTA uses the standard and enhanced Mori-Tanaka type models combined with the Eshelby equivalent inclusion method to predict the thermoelastic properties of the composite based on its microstructure.

  7. Comparison of stress and total energy methods for calculation of elastic properties of semiconductors

    NASA Astrophysics Data System (ADS)

    Caro, M. A.; Schulz, S.; O'Reilly, E. P.

    2013-01-01

    We explore the calculation of the elastic properties of zinc-blende and wurtzite semiconductors using two different approaches: one based on stress and the other on total energy as a function of strain. The calculations are carried out within the framework of density functional theory in the local density approximation, with the plane wave-based package vasp. We use AlN as a test system, with some results also shown for selected other materials (C, Si, GaAs and GaN). Differences are found in convergence rate between the two methods, especially in low symmetry cases, where there is a much slower convergence for total energy calculations with respect to the number of plane waves and k points used. The stress method is observed to be more robust than the total energy method with respect to the residual error in the elastic constants calculated for different strain branches in the systems studied.

  8. Cross sections for neutron-deuteron elastic scattering in the energy range 135–250 MeV

    E-print Network

    Ertan, E.

    We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from 80[degrees] to 130[degrees]. Cross sections for neutron-proton elastic ...

  9. Utilization of stored elastic energy in leg extensor muscles by men and women.

    PubMed

    Komi, P V; Bosco, C

    1978-01-01

    An alternating cycle of eccentric-concentric contractions in locomotion represents a sequence when storage and utilization of elastic energy takes place. It is possible that this storage capacity and its utilization depends on the imposed stretch loads in activated muscles, and that sex differences may be present in these phenomena. To investigate these assumed differences, subjects from both sexes and of good physical condition performed vertical jumps on the force-platform from the following experimental conditions: squatting jump (SJ) from a static starting position; counter-movement jump (CMJ) from a free standing position and with a preparatory counter-movement; drop jumps (DJ) from the various heights (20 to 100 cm) on to the platform followed immediately by a vertical jump. In all subjects the SJ, in which condition no appreciable storage of elastic energy takes place, produced the lowest height of rise of the whole body center of gravity (C.G.). The stretch load (drop height) influenced the performance so that height of rise of C. of G. increased when the drop height increased from 26 up to 62 cm (males) and from 20 to 50 cm (females). In all jumping conditions the men jumped higher than the women. However, examination of the utilization of elastic energy indicated that in CMJ the female subjects were able to utilize most (congruent to 90%) of the energy produced in the prestretching phase. Similarly, in DJ the overall change in positive energy over SJ condition was higher in women as compared to men. Thus the results suggest that although the leg extensor muscles of the men subjects could sustain much higher stretch loads, the females may be able to utilize a greater portion of the stored elastic energy in jumping activities. PMID:750844

  10. Incorporating elastic and plastic work rates into energy balance for long-term tectonic modeling

    NASA Astrophysics Data System (ADS)

    Ahamed, M. S.; Choi, E.

    2014-12-01

    Deformation-related energy budget is usually considered in the simplest form or even completely omitted from the energy balance equation. We derive an energy balance equation that accounts not only for heat energy but also for elastic and plastic work. Such a general description of the energy balance principle will be useful for modeling complicated interactions between geodynamic processes such as thermoelastisity, thermoplasticity and mechanical consequences of metamorphism. Following the theory of large deformation plasticity, we start from the assumption that Gibbs free energy (g) is a function of temperature (T), the second Piola-Kirchhoff stress (S), density (?) and internal variables (qj, j=1…n). In this formulation, new terms are derived, which are related to the energy dissipated through plastic work and the elastically stored energy that are not seen in the usual form of the energy balance equation used in geodynamics. We then simplify the generic equation to one involving more familiar quantities such as Cauchy stress and material density assuming that the small deformation formulation holds for our applications. The simplified evolution equation for temperature is implemented in DyanEarthSol3D, an unstructured finite element solver for long-term tectonic deformation. We calculate each of the newly derived terms separately in simple settings and compare the numerical results with a corresponding analytic solution. We also present the effects of the new energy balance on the evolution of a large offset normal fault.

  11. Low Energy Elastic Electron Scattering from Gaseous Tetrahydrofuran

    NASA Astrophysics Data System (ADS)

    Gauf, Alexsander; Jo, Amos; Walls, Todd; Hargreaves, Leigh; Khakoo, Murtadha A.

    2011-10-01

    Normalized absolute experimental electron scattering differential cross-sections (DCS) for electron energies of 1.5eV to 50eV from tetrahydrofuran will be presented. The experimental method employs the relative flow method using helium as the calibration gas, but a moveable source arrangement to accurately determine the experimental background. The results extend experimentally available DCS at lower energies and are found to be in very good agreement with earlier measurements in general. However, our results, using a thin aperture gas source, are not constrained by molecular diameter requirements and serve as a useful systematic check of earlier results (see and the references therein). Funded by an NSFGrant # RUI-PHY 0968874.

  12. Renewable Energy Potentials in Saudi Arabia

    Microsoft Academic Search

    S. A. M. Said; I. M. El-Amin; A. M. Al-Shehri

    This paper addresses the current status and the future potentials of renewable energy applications in the Kingdom of Saudi Arabia. The power in the earth's wind and in the solar radiation, which reaches the earth, is sufficient to make significant as well as strategic contributions to the Kingdom energy supply. Applications of solar energy in Saudi Arabia have been growing

  13. Geothermal Energy Potential in Western United States

    ERIC Educational Resources Information Center

    Pryde, Philip R.

    1977-01-01

    Reviews types of geothermal energy sources in the western states, including hot brine systems and dry steam systems. Conversion to electrical energy is a major potential use of geothermal energy, although it creates environmental disruptions such as noise, corrosion, and scaling of equipment. (AV)

  14. Radius exponent in elastic and rigid arterial models optimized by the least energy principle

    PubMed Central

    Nakamura, Yoshihiro; Awa, Shoichi

    2014-01-01

    Abstract It was analyzed in normal physiological arteries whether the least energy principle would suffice to account for the radius exponent x. The mammalian arterial system was modeled as two types, the elastic or the rigid, to which Bernoulli's and Hagen?Poiseuille's equations were applied, respectively. We minimized the total energy function E, which was defined as the sum of kinetic, pressure, metabolic and thermal energies, and loss of each per unit time in a single artery transporting viscous incompressible blood. Assuming a scaling exponent ? between the vessel radius (r) and length (l) to be 1.0, x resulted in 2.33 in the elastic model. The rigid model provided a continuously changing x from 2.33 to 3.0, which corresponded to Uylings’ and Murray's theories, respectively, through a function combining Reynolds number with a proportional coefficient of the l ? r relationship. These results were expanded to an asymmetric arterial fractal tree with the blood flow preservation rule. While x in the optimal elastic model accounted for around 2.3 in proximal systemic (r >1 mm) and whole pulmonary arteries (r ?0.004 mm), optimal x in the rigid model explained 2.7 in elastic?muscular (0.1 < r ?1 mm) and 3.0 in peripheral resistive systemic arteries (0.004 ? r ?0.1 mm), in agreement with data obtained from angiographic, cast?morphometric, and in vivo experimental studies in the literature. The least energy principle on the total energy basis provides an alternate concept of optimality relating to mammalian arterial fractal dimensions under ? = 1.0. PMID:24744905

  15. Low-energy electron elastic scattering from Mn, Cu, Zn, Ni, Ag, and Cd atoms

    SciTech Connect

    Felfli, Z.; Msezane, A. Z. [Department of Physics and Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, Georgia 30314 (United States); Sokolovski, D. [School of Mathematics and Physics, Queen's University of Belfast, Belfast, BT7 1NN (United Kingdom); Department of Chemical Physics, University of the Basque Country, Leioa (Spain)

    2011-05-15

    Electron elastic total cross sections (TCSs) for ground and excited Mn, Cu, Zn, Ni, Ag, and Cd atoms have been investigated in the electron-impact energy range 0 {<=}E{<=} 1 eV. The near-threshold TCSs for both the ground and excited states of these atoms are found to be characterized by Ramsauer-Townsend minima, shape resonances, and extremely sharp resonances corresponding to the formation of stable bound negative ions. The recently developed Regge-pole methodology where the crucial electron-electron correlations are embedded is employed for the calculations. From close scrutiny of the imaginary parts of the complex angular momenta, we conclude that these atoms form stable weakly bound ground and excited negative ions as Regge resonances through slow electron collisions. The extracted electron binding energies from the elastic TCSs of these atoms are contrasted with the available experimental and theoretical values.

  16. Unlocking potential for energy reduction.

    PubMed

    O'Leary, John

    2013-05-01

    In the latest of our series of articles designed to provide healthcare engineers with sound technical guidance on equipment or technology-related topics, John O'Leary, key account manager at Trend Controls (who in April's HEJ discussed the benefits of natural ventilation in healthcare settings), explains the functions of a building energy management system (BEMS), and the vital that role such equipment can play in helping healthcare estates teams reduce carbon emissions and save money, as well as ensuring the most comfortable environment for patients, staff, and visitors. PMID:23763085

  17. Experimental apparatus for the study of small angle neutron-proton elastic scattering at intermediate energies

    NASA Astrophysics Data System (ADS)

    Vorobyov, A. A.; Korolev, G. A.; Dobrovolsky, A. V.; Khanzadeev, A. V.; Petrov, G. E.; Spiridenkov, E. M.; Terrien, Y.; Lugol, J. C.; Saudinos, J.; Silverman, B. H.; Wellers, F.

    1988-07-01

    An experimental setup for measurements of absolute differential cross sections and analyzing powers in small angle elastic np scattering is described. The main part of the apparatus consists of a multielectrode ionization chamber IKAR filled with methane, serving as both a gas target and a recoil detector. The apparatus was used in measurements with a polarized neutron beam from the Saturne synchrotron (Saclay, France) in the energy range from 378 to 1135 MeV.

  18. Low-energy electron impact elastic and inelastic scattering from CF3I

    NASA Astrophysics Data System (ADS)

    Kitajima, M.; Okamoto, M.; Sunohara, K.; Tanaka, H.; Cho, H.; Samukawa, S.; Eden, S.; Mason, N. J.

    2002-08-01

    Absolute differential cross sections for elastic scattering from CF3I are reported between 1.5 and 60 eV and over scattering angles of 20°-130°. Vibrational excitation cross sections for the composite stretching modes are shown to be preferentially enhanced at incident electron energies between 5 and 9 eV indicating the formation of short-lived shape resonances.

  19. Elastic Scattering and Vibrational Excitation of Tetrahydrofuran by Low Energy Electrons

    NASA Astrophysics Data System (ADS)

    Orton, Danny; Gauf, Alexsander; Jo, Amos; Tanner, Joshua; Khakoo, Murtadha A.; Walls, Todd; Winstead, Carl; McKoy, Vincent

    2012-10-01

    We report experimental and theoretical (Schwinger Multi-Channel method with polarization effects) differential cross-sections (DCS) for low energy elastic electron scattering from tetrahydrofuran. The data are for incident energies from 0.75 to 30eV and the experimental scattering angles range from 10^o to 130^o. Agreement between theory and experiment is very good across the range of this data. Comparisons with previous experiments is also very good in general. We will also report DCSs for vibrational excitation of this target for energies up to 15eV and similar scattering angles.

  20. Monte Carlo simulation of ferroelectric domain structure: Electrostatic and elastic strain energy contributions

    SciTech Connect

    POTTER JR.,BARRETT G.; TUTTLE,BRUCE A.; TIKARE,VEENA

    2000-04-04

    A lattice-Monte Carlo approach was developed to simulate ferroelectric domain behavior. The model utilizes a Hamiltonian for the total energy that includes electrostatic terms (involving dipole-dipole interactions, local polarization gradients, and applied electric field), and elastic strain energy. The contributions of these energy components to the domain structure and to the overall applied field response of the system were examined. In general, the model exhibited domain structure characteristics consistent with those observed in a tetragonally distorted ferroelectric. Good qualitative agreement between the appearance of simulated electrical hysteresis loops and those characteristic of real ferroelectric materials was found.

  1. Energy-like Liapunov functionals for linear elastic systems on a Hilbert space.

    NASA Technical Reports Server (NTRS)

    Walker, J. A.

    1973-01-01

    An approach is presented for generating energy-like functionals for linear elastic dynamic systems on a Hilbert space. The objective is to obtain a family of functionals which may be used for stability analysis of the equilibrium, i.e., Liapunov functionals. Although the energy functional, when one exists, is always a member of this family, the family is shown to exist even when an energy functional does not. Several discrete and distributed-parameter examples are presented, as are certain specific techniques for utilizing this approach.

  2. Absolute Beam Energy Measurement using Elastic ep Scattering at Thomas Jefferson National Accelerator Facility

    NASA Astrophysics Data System (ADS)

    Deur, Alexandre

    1999-10-01

    The Jefferson Lab beam energy measurement in Hall A using the elastic ep scattering will be described. This new, non-magnetic, energy measurement method allows a ( triangle E/E=10-4 ) precision. First-order corrections are canceled by the measurements of the electron and proton scattering angles for two symmetric kinematics. The measurement principle will be presented as well as the device and measurement results. Comparison with independent magnetic energy measurements of the same accuracy will be shown. This project is the result of a collaboration between the LPC: université Blaise Pascal/in2p3), Saclay and Jefferson Lab.

  3. Outstanding mechanical properties of monolayer MoS2 and its application in elastic energy storage

    NASA Astrophysics Data System (ADS)

    Peng, Qing; de, Suvranu

    2014-03-01

    The structural and mechanical properties of graphene-like honeycomb monolayer structures of MoS2(g-MoS2) under various large strains are investigated using density functional theory (DFT). g-MoS2 is mechanically stable and can sustain extra large strains: the ultimate strains are 0.24, 0.37, and 0.26 for armchair, zigzag, and biaxial deformation, respectively. The in-plane stiffness is as high as 120 N/m (184 GPa equivalently). The third, fourth, and fifth order elastic constants are indispensable for accurate modeling of the mechanical properties under strains larger than 0.04, 0.07, and 0.13 respectively. The second order elastic constants, including in-plane stiffness, are predicted to monotonically increase with pressure while the Poisson ratio monotonically decreases with increasing pressure. With the prominent mechanical properties including large ultimate strains and in-plane stiffness, g-MoS2 is a promising candidate of elastic energy storage for clean energy. It possesses a theoretical energy storage capacity as high as 8.8 MJ/L and 1.7 MJ/kg, or 476 Wh/kg, larger than a Li-ion battery and is environmentally friendly. Financial support from the Defence Threat Reduction Agency (DTRA) Grant # BRBAA08-C-2-0130 and.

  4. Effective Potential Energy Expression for Membrane Transport

    E-print Network

    Robert W. Finkel

    2007-02-11

    All living cells transport molecules and ions across membranes, often against concentration gradients. This active transport requires continual energy expenditure and is clearly a nonequilibrium process for which standard equilibrium thermodynamics is not rigorously applicable. Here we derive a nonequilibrium effective potential that evaluates the per particle transport energy invested by the membrane. A novel method is used whereby a Hamiltonian function is constructed using particle concentrations as generalized coordinates. The associated generalized momenta are simply related to the individual particle energy from which we identify the effective potential. Examples are given and the formalism is compared with the equilibrium Gibb's free energy.

  5. Energy saving potential of various roof technologies

    E-print Network

    Ray, Stephen D. (Stephen Douglas)

    2010-01-01

    Unconventional roof technologies such as cool roofs and green roofs have been shown to reduce building heating and cooling load. Although previous studies suggest potential for energy savings through such technologies, ...

  6. Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping.

    PubMed

    Astley, Henry C; Roberts, Thomas J

    2012-06-23

    Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid joint movement during the jump without rapid muscle-shortening (during tendon recoil). During all jumps, muscle fascicles shortened by an average of 7.8 per cent (54% of total strain) prior to joint movement, stretching the tendon. The subsequent period of initial joint movement and high joint angular acceleration occurred with minimal muscle fascicle length change, consistent with the recoil of the elastic tendon. These data support the plantaris longus tendon as a site of elastic energy storage during frog jumping, and demonstrate that catapult mechanisms may be employed even in sub-maximal jumps. PMID:22090204

  7. Potential of energy production from conserved forages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forages have a potential role in meeting the demand for energy. Perennial forages are attractive for various reasons. One, both the monetary and energy cost of planting is spread over many years. Two, we already have the equipment for harvesting, storing and transporting this source of biomass. Thre...

  8. Potential for energy conservation in apartment buildings

    Microsoft Academic Search

    C. A Balaras; K Droutsa; A. A Argiriou; D. N Asimakopoulos

    2000-01-01

    The potential for energy conservation in apartment buildings is investigated following the epiqr methodology and software. Several scenarios are evaluated for various apartment buildings located in three climatic zones of Hellas. The proposed retrofit actions concentrate on space heating and cooling, domestic hot water production and lighting. Energy savings for the corresponding actions in each building are accounted for in

  9. A method to estimate the elastic energy stored in braided DNA molecules using hydrodynamic equations.

    PubMed

    Fernández-Sierra, Mónica; Delgado-Martí, Violeta; Colón-García, Jorge E; Quiñones, Edwin

    2011-05-26

    We present a single-molecule method for measuring the torque exerted by braided DNA molecules undergoing spontaneous unbraiding while attached to a paramagnetic dumbbell in the absence of external manipulation. A magnetic tweezers setup is employed to braid pairs of lambda DNA molecules covalently bound to a surface. Upon removing the magnetic field, the braided DNA molecules undergo spontaneous unbraiding, efficiently transforming the stored elastic energy into enough mechanical energy to rotate the tethered dumbbells for periods as long as 30 minutes. Using hydrodynamic equations we estimate the torque exerted on the dumbbells by the DNA braids, yielding values ranging from 47 to 166 pN nm. PMID:21765578

  10. Enhancement of transdermal absorption, gene expression and stability of tyrosinase plasmid (pMEL34)-loaded elastic cationic niosomes: potential application in vitiligo treatment.

    PubMed

    Manosroi, Jiradej; Khositsuntiwong, Narinthorn; Manosroi, Worapaka; Götz, Friedrich; Werner, Rolf G; Manosroi, Aranya

    2010-08-01

    The pMEL34 was loaded in elastic cationic niosomes (Tween61/Cholesterol/DDAB at 1:1:0.5 molar ratio) by chloroform film method with sonication and rehydrated with 25% ethanol. The amount of pMEL34 was determined by gel electrophoresis and gel documentation. The maximum loading of pMEL34 in elastic cationic niosomes was 150 microg/16 mg of the niosomal compositions. At 8 weeks, the remaining plasmid in the elastic niosomes kept at 4 +/- 2 degrees C, 27 +/- 2 degrees C were 49.75% and 38.57%, respectively, whereas at 45 +/- 2 degrees C, all plasmids were degraded. For transdermal absorption through rat skin investigated by Franz diffusion cells at 6 h, the fluxes of pMEL34 loaded in elastic and nonelastic niosomes in viable epidermis and dermis (VED) were 0.022 +/- 0.00 and 0.017 +/- 0.01 microg/cm(2)/h, respectively, whereas only pMEL34 loaded in elastic cationic noisome was observed in the receiver solution. The pMEL34 loaded in elastic cationic niosomes showed the highest tyrosinase gene expression demonstrating higher tyrosinase activity than the free and the loaded plasmid in nonelastic niosomes of about four times. This study has suggested the potential application of elastic cationic niosomes as an efficient topical delivery for tyrosinase gene in vitiligo therapy. PMID:20213835

  11. Elastic scattering of low energy pions by nuclei and the in-medium isovector pi N amplitude

    E-print Network

    E. Friedman; M. Bauer; J. Breitschopf; H. Clement; H. Denz; E. Doroshkevich; A. Erhardt; G. J. Hofman; S. Kritchman; R. Meier; G. J. Wagner; G. Yaari

    2005-08-21

    Measurements of elastic scattering of 21.5 MeV pi+ and pi- by Si, Ca, Ni and Zr were made using a single arm magnetic spectrometer. Absolute calibration was made by parallel measurements of Coulomb scattering of muons. Parameters of a pion-nucleus optical potential were obtained from fits to all eight angular distributions put together. The `anomalous' s-wave repulsion known from pionic atoms is clearly observed and could be removed by introducing a chiral-motivated density dependence of the isovector scattering amplitude, which also greatly improved the fits to the data. The empirical energy dependence of the isoscalar amplitude also improves the fits to the data but, contrary to what is found with pionic atoms, on its own is incapable of removing the anomaly.

  12. Nonlinear elastic effects on the energy flux deviation of ultrasonic waves in gr/ep composites

    NASA Technical Reports Server (NTRS)

    Prosser, William H.; Kriz, R. D.; Fitting, Dale W.

    1992-01-01

    The effects of nonlinear elasticity on energy flux deviation in undirectional gr/ep composites are examined. The shift in the flux deviation is modeled using acoustoelasticity theory and the second- and third-order elastic stiffness coefficients for T300/5208 gr/ep. Two conditions of applied uniaxial stress are considered. In the first case, the direction of applied uniaxial stress was along the fiber axis (x3), while in the second case it was perpendicular to the fiber axis along the laminate stacking direction (x1). For both conditions, the change in the energy flux deviation angle from the condition of zero applied stress is computed over the range of propagation directions of 0 to 60 deg from the fiber axis at two-degree intervals. A positive flux deviation angle implies the energy deviates away from the fiber direction toward the x1 axis, while a negative deviation means that the energy deviates toward the fibers. Over this range of fiber orientation angles, the energy of the quasi-longitudinal and pure mode transverse waves deviates toward the fibers, while that of the quasi-transverse mode deviates away from the fibers.

  13. Quantum potential energy as concealed motion

    E-print Network

    Peter Holland

    2014-11-13

    It is known that the Schroedinger equation may be derived from a hydrodynamic model in which the Lagrangian position coordinates of a continuum of particles represent the quantum state. Using Routh\\s method of ignorable coordinates it is shown that the quantum potential energy of particle interaction that represents quantum effects in this model may be regarded as the kinetic energy of additional concealed freedoms. The method brings an alternative perspective to Planck\\s constant, which plays the role of a hidden variable, and to the canonical quantization procedure, since what is termed kinetic energy in quantum mechanics may be regarded literally as energy due to motion.

  14. Potential energy function for the hydroperoxyl radical

    SciTech Connect

    Lemon, W.J.; Hase, W.L.

    1987-03-12

    A switching function formalism is used to derive an analytic potential energy surface for the O + OH in equilibrium HO/sub 2/ in equilibrium H + O/sub 2/ reactive system. Both experimental and ab initio data are used to derive parameters for the potential energy surface. Trajectory calculations for highly excited HO/sub 2/ are performed on this surface. From these trajectories quasi-periodic eigentrajectories are found for vibrational levels near the HO/sub 2/ dissociation threshold with small amounts of quanta in the OH stretch mode and large amounts of quanta in the OO stretch mode.

  15. Storing unsteady energy, like photovoltaically generated electric energy, as potential energy

    E-print Network

    Nadja Kutz

    2012-02-13

    A proposal to store unsteady energy in potential energy via lifting masses with a rough quantitative overview. Some applications and methods to harvest the potential energy are also given. A focus is put on photovoltaically generated energy.

  16. Energy dependence of slope parameter in elastic nucleon-nucleon scattering

    E-print Network

    Okorokov, V A

    2015-01-01

    The study of slope parameter is presented for elastic proton-proton and antiproton-proton scattering with taking into account the resent experimental data at high energies. The expanded logarithmic approximations allow the description of the experimental slopes in all available energy range reasonably. Accounting for the LHC results leads to the dramatic change of behavior of the quadratic in logarithm approximation at high energies and to the closer trends for all fitting functions under study in comparison with the analysis at collision energies up to the 200 GeV. The estimations of the asymptotic shrinkage parameter $\\alpha'_{\\cal{P}}$ are discussed. Predictions for diffraction slope parameter are obtained for some proton-proton and antiproton-proton facilities.

  17. Energy dependence of slope parameter in elastic nucleon-nucleon scattering

    E-print Network

    V. A. Okorokov

    2015-06-18

    The study of slope parameter is presented for elastic proton-proton and antiproton-proton scattering with taking into account the resent experimental data at high energies. The expanded logarithmic approximations allow the description of the experimental slopes in all available energy range reasonably. Accounting for the LHC results leads to the dramatic change of behavior of the quadratic in logarithm approximation at high energies and to the closer trends for all fitting functions under study in comparison with the analysis at collision energies up to the 200 GeV. The estimations of the asymptotic shrinkage parameter $\\alpha'_{\\cal{P}}$ are discussed. Predictions for diffraction slope parameter are obtained for some proton-proton and antiproton-proton facilities.

  18. Price and income elasticities of energy demand: Some estimates for Kuwait using two econometric models

    SciTech Connect

    Al-Mutairi, N.H.; Eltony, M.N.

    1995-12-31

    This paper estimates the demand for energy in Kuwait for the period 1965-1989 using two econometric models: a cointegration and error correction model (ECM) and a simultaneous-equation model (SEM). The results obtained from both models are similar. It is found that the energy demand is inelastic with respect to price in the short and long run, and while it is elastic in the long run, the energy demand is inelastic with respect to income in the short run. Both models` validation shows that the ECM performed better in replicating the past than the simultaneous model, suggesting the need to use the ECM to identify future prospects for energy demand in Kuwait.

  19. Prospects for constraining the dark energy potential

    NASA Astrophysics Data System (ADS)

    Fernandez-Martinez, Enrique; Verde, Licia

    2008-08-01

    We generalize to non-flat geometries the formalism of Simon et al (2005 Phys. Rev. D 71 123001 [astro-ph/0412269]) to reconstruct the dark energy potential. This formalism makes use of quantities similar to the horizon-flow parameters in inflation, can, in principle, be made non-parametric and is general enough to be applied outside the simple, single-scalar-field quintessence. Since currently available and forthcoming data do not allow a non-parametric and exact reconstruction of the potential, we consider a general parametric description in terms of Chebyshev polynomials. We then consider present and future measurements of H(z), baryon acoustic oscillation (BAO) surveys and supernovae type 1A surveys, and investigate their constraints on the dark energy potential. We find that relaxing the flatness assumption increases the errors in the reconstructed dark energy evolution but does not open up significant degeneracies, provided that a modest prior is imposed on the geometry. Direct measurements of H(z), such as those provided by BAO surveys, are crucially important for constraining the evolution of the dark energy potential and the dark energy equation of state, especially for non-trivial deviations from the standard ?CDM (CDM: cold dark matter) model.

  20. Prospects in Constraining the Dark Energy Potential

    E-print Network

    Enrique Fernandez-Martinez; Licia Verde

    2008-08-14

    We generalize to non-flat geometries the formalism of Simon et al. (2005) to reconstruct the dark energy potential. This formalism makes use of quantities similar to the Horizon-flow parameters in inflation, can, in principle, be made non-parametric and is general enough to be applied outside the simple, single scalar field quintessence. Since presently available and forthcoming data do not allow a non-parametric and exact reconstruction of the potential, we consider a general parametric description in term of Chebyshev polynomials. We then consider present and future measurements of H(z), Baryon Acoustic Oscillations surveys and Supernovae type 1A surveys, and investigate their constraints on the dark energy potential. We find that, relaxing the flatness assumption increases the errors on the reconstructed dark energy evolution but does not open up significant degeneracies, provided that a modest prior on geometry is imposed. Direct measurements of H(z), such as those provided by BAO surveys, are crucially important to constrain the evolution of the dark energy potential and the dark energy equation of state, especially for non-trivial deviations from the standard LambdaCDM model.

  1. Energy conservation in Kenya: progress, potentials, problems

    SciTech Connect

    Schipper, L.; Hollander, J.M.; Milukas, M.; Alcamo, J.; Meyers, S.; Noll, S.

    1981-09-01

    A study was carried out of the flows of commercial energy in the economy of Kenya. Indications were sought of the extent to which energy conservation, (i.e., increase in efficiency of energy use) has reduced the ratio of energy inputs to economic outputs, in the post-1973 years. An assessment was made of the potential for energy conservation to reduce the growth of Kenyan energy use in the future and of significant barriers to increasing energy efficiency. Consideration was given to the role of government policy and of international assistance in fostering energy conservation in Kenya and other developing countries. The study was performed by analyzing available energy data and statistics from the largest oil companies, the Kenyan electric utility, and the government. These sources were supplemented by conducting personal interviews with personnel of nearly 50 commercial firms in Kenya. Direct consumption of fuel accounts for 94% of the commercial energy use in Kenya, while electricity accounts for 6%. The sectoral division of fuel use is: transportation 53%, industry 21%, energy production 11%, agriculture 9%, buildings and residences 5%, and construction 1%. For electricity the division is: buildings and residences 48%, industry 45%, energy production 4%, agriculture 2%, and construction 1%. Recent progress in conservation is reported.

  2. Energy Potential of Municipal Solid Wastes

    Microsoft Academic Search

    Deniz Dolgen; Hasan Sarptas; Necdet Alpaslan; Orhan Kucukgul

    2005-01-01

    In this article, energy recovery from municipal solid wastes is examined. The fuel characteristics of solid waste components as well as the landfill gas (LFG) yield are reviewed. The energy potential of solid wastes of Izmir (third biggest city of Turkey) is then estimated. The heating value is calculated at about 3,500–5,500 kJ\\/kg, particularly in urban places, whereas it is

  3. Forward elastic amplitudes of high-energy pions and kaons on nuclei

    NASA Astrophysics Data System (ADS)

    Chen, C. M.; Johnson, Mikkel B.; Ernst, D. J.

    1998-12-01

    Experimental elastic angular distributions for pions and kaons in the region of laboratory momentum from 600 to 900 MeV/c over the nuclear-Coulomb interference region are analyzed to extract both the real and imaginary part of the forward meson-nucleus scattering amplitude. For pions, results for the total cross sections extracted are smaller than those found from transmission experiments. The real part of the amplitude is found to have an interesting energy dependence. The significance of this result for the behavior of hadrons in nuclei is discussed. For kaons, only qualitative results were obtained due to limited data.

  4. Extraction of Neutron Density Distributions from Proton Elastic Scattering at Intermediate Energies

    NASA Astrophysics Data System (ADS)

    Takeda, H.; Sakaguchi, H.; Terashima, S.; Taki, T.; Yosoi, M.; Itoh, M.; Kawabata, T.; Ishikawa, T.; Uchida, M.; Tsukahara, N.; Yasuda, Y.; Noro, T.; Yoshimura, M.; Fujimura, H.; Yoshida, H. P.; Obayashi, E.; Tamii, A.; Akimune, H.

    2003-07-01

    Cross sections, analyzing powers and spin rotation parameters of proton elastic scattering from 58Ni and 120Sn have been measured at intermediate energies. Obtained data have been analyzed in the framework of relativistic impulse approximations. In order to explain the 58Ni data, it was necessary to modify NN interactions in the nuclear medium by changing coupling constants and masses of ? and ? mesons. For 120Sn, by assuming the same modification of NN interactions and by using proton densities deduced from charge densities, the neutron density distribution was searched so as to reproduce 120Sn data at 300 MeV.

  5. Extraction of neutron density distributions from proton elastic scattering at intermediate energies

    NASA Astrophysics Data System (ADS)

    Takeda, H.; Sakaguchi, H.; Taki, T.; Yosoi, M.; Itoh, M.; Kawabata, T.; Ishikawa, T.; Uchida, M.; Tsukahara, N.; Noro, T.; Yoshimura, M.; Fujimura, H.; Yoshida, H. P.; Obayashi, E.; Tamii, A.; Akimune, H.

    2002-04-01

    Cross sections, analyzing powers and spin rotation parameters of proton elastic scattering from 58Ni and 120Sn have been measured at intermediate energies. In order to explain the 58Ni data, it was necessary to use experimental density distributions deduced from charge distributions and to modify coupling constants and masses of ? and ? mesons. For 120Sn, assuming the same modification and using proton densities deduced from charge densities, neutron density distribution was searched so as to reproduce 120Sn data. Effects of ? meson modifications are also discussed. .

  6. Optimal utilization of total elastic scattering cross section data for the determination of interatomic potentials

    NASA Technical Reports Server (NTRS)

    Bernstein, R. B.; Labudde, R. A.

    1972-01-01

    The problem of inversion is considered in relation to absolute total cross sections Q(v) for atom-atom collisions and their velocity dependence, and the glory undulations and the transition to high velocity behavior. There is a limit to the amount of information available from Q(v) even when observations of good accuracy (e.g., + or - 0.25%) are in hand over an extended energy range (from thermal energies upward by a factor of greater than 1000 in relative kinetic energy). Methods were developed for data utilization, which take full advantage of the accuracy of the experimental Q(v) measurements.

  7. Gravity-driven groundwater flow and slope failure potential. 1. Elastic effective-stress model

    Microsoft Academic Search

    Richard M. Iverson; Mark E. Reid

    1992-01-01

    Hilly or mountainous topography influences gravity-driven groundwater flow and the consequent distribution of effective stress in shallow subsurface environments. Effective stress, in turn, influences the potential for slope failure. To evaluate these influences, the authors formulate a two-dimensional, steady state, poroelastic model. The governing equations incorporate groundwater effects as body forces, and they demonstrate that spatially uniform pore pressure changes

  8. Gravity-driven groundwater flow and slope failure potential: 1. Elastic Effective-Stress Model

    Microsoft Academic Search

    Richard M. Iverson; Mark E. Reid

    1992-01-01

    Hilly or mountainous topography influences gravity-driven groundwater flow and the consequent distribution of effective stress in shallow subsurface environments. Effective stress, in turn, influences the potential for slope failure. To evaluate these influences, we formulate a two-dimensional, steady state, poroelastic model. The governing equations incorporate groundwater effects as body forces, and they demonstrate that spatially uniform pore pressure changes do

  9. Gravity-Driven Groundwater Flow and Slope Failure Potential 1. Elastic Effective-Stress Model

    Microsoft Academic Search

    Richard M. Iverson; Mark E. Reid

    1992-01-01

    Hilly or mountainous topography influences gravity-driven groundwater flow and the consequent distribution of effective stress in shallow subsurface environments. Effective stress, in turn, influences the potential for slope failure. To evaluate these influences, we formulate a two-dimensional, steady state, poroelastic model. The governing equations incorporate groundwater effects as body forces, and they demonstrate that spatially uniform pore pressure changes do

  10. Observations of resonance-like structures for positron-atom elastic scattering at intermediate energies

    SciTech Connect

    Dou, L.; Kauppila, W.E.; Kwan, C.K.; Stein, T.S.

    1993-05-01

    We have measured absolute values of elastic differential cross sections (DCS`s) for positron (e{sup +}) scattering by argon (8.7-300 eV), krypton (6.7-400 eV), and also neon (13.6-400 eV) using a crossed-beam experimental setup. When the DCS`s are plotted at fixed scattering angles of 30{degrees}, 60{degrees}, 90{degrees}, and 120{degrees} versus energy it has been found that well-defined resonance-like structures were found at an energy of 55-60 eV for argon and at 25 and 200 eV for krypton, with a broader structure found between 100-200 eV for neon. These observed resonance-like structures are unusual because they occur at energies well above the known inelastic thresholds for these atoms. They may represent examples of {open_quotes}coupled channel shape resonances{close_quotes}, first predicted by Higgins and Burke for e{sub +}-H scattering in the vicinity of 36 eV (width {approx} 4 eV), which occurs only when both the elastic and positronium formation scattering channels are considered together. A more recent e{sup +}-H calculation by Hewitt et al. supports the Higgins and Burke prediction. These predictions and the present observations suggest the existence of a new type of atomic scattering resonance.

  11. Energy dependence of the {rho} resonance in {pi} {pi} elastic scattering from lattice QCD

    SciTech Connect

    Jozef Dudek, Robert Edwards, Christopher Thomas

    2013-02-01

    We determine the energy-dependent amplitude for elastic {pi} {pi} P-wave scattering in isospin-1 by computing part of the discrete energy spectrum of QCD in finite cubic boxes. We observe a rapidly rising phase shift that can be well described by a single {rho} Resonance. The spectrum is obtained from hadron correlators computed using lattice QCD with light quark masses corresponding to m{sub {pi}}~400 MeV. Variational analyses are performed with large bases of hadron interpolating fields including, as well as fermion bilinears that resemble q{anti q} Constructions, also operators that look like pairs of pions with definite relative and total momentum. We compute the spectrum for a range of center-of-mass momenta and in various irreducible representations of the relevant symmetry group. Hence we determine more than thirty values of the isospin-1 P-wave scattering phase shift in the elastic region, mapping out its energy dependence in unprecedented detail.

  12. Biomass resource potential using energy crops

    SciTech Connect

    Wright, L.L.; Cushman, J.H.; Martin, S.A.

    1993-09-01

    Biomass energy crops can provide a significant and environmentally beneficial source of renewable energy feedstocks for the future. They can revitalize the agricultural sector of the US economy by providing profitable uses for marginal cropland. Energy crops include fast-growing trees, perennial grasses, and annual grasses, all capable of collecting solar energy and storing it as cellulosic compounds for several months to several years. Once solar energy is thus captured, it can be converted by means of currently available technologies to a wide variety of energy products such as electricity, heat, liquid transportation fuels, and gases. Experimental results from field trials have generated optimism that selected and improved energy crops, established on cropland with moderate limitations for crop production, have the potential for producing high yields. Both trees and grasses, under very good growing conditions, have produced average annual yields of 20 to 40 dry Mg ha{sup {minus}1} year{sup {minus}1}. Sorghum has shown especially high yields in the Midwest. Hybrids between sugar cane and its wild relatives, called energy cane, have yielded as much as 50 dry Mg ha{sup {minus}1} year{sup {minus}1} in Florida. These experimental results demonstrate that some species have the genetic potential for very rapid growth rates. New wood energy crop systems developed by the Department of Energy`s Biofuels Feedstock Development Program offer, at a minimum, a 100% increase in biomass production rates over the 2 to 4 Mg ha{sup {minus}1} year{sup {minus}1} of dry leafless woody biomass produced by most natural forest systems. Experimental data indicate that short rotation wood crops established on cropland with moderate limitations are capable of producing biomass yields of 8--20 dry Mg ha{sup {minus}1} year{sup {minus}1} with a present average about 11 dry Mg ha{sup {minus}1} year{sup {minus}1} on typical cropland sites.

  13. Nudged-elastic band used to find reaction coordinates based on the free energy.

    PubMed

    Bohner, Matthias U; Zeman, Johannes; Smiatek, Jens; Arnold, Axel; Kästner, Johannes

    2014-02-21

    Transition paths characterize chemical reaction mechanisms. In this paper, we present a new method to find mean reaction paths based on the free energy. A nudged elastic band (NEB) is optimized using gradients and Hessians of the free energy, which are obtained from umbrella integration. The transition state can be refined by a Newton-Raphson search starting from the highest point of the NEB path. All optimizations are done using Cartesian coordinates. Independent molecular dynamics (MD) runs are performed at each image used to discretize the path. This makes the method intrinsically parallel. In contrast to other free energy methods, the algorithm does not become more expensive when including more degrees of freedom in the active space. The method is applied to the alanine-dipeptide as a test case and compared to pathways that have been derived from metadynamics and forward flux sampling. PMID:24559340

  14. Application of valence force field theory, tight binding approximation and Girifalco potential in the study of thermodynamic and elastic properties of C 60 in detail

    Microsoft Academic Search

    R. V. Gopala Rao; R. Venkatesh

    2001-01-01

    In this paper we calculated the second order elastic constants (SOECs) of C60 using tight binding approximation (TBA) and valence force field theory (VFFT). To the SOECs obtained from Girifalco potential we added the contribution of Coloumb forces obtained through Martins prescription and the corrected values so obtained compare favorably with those of TBA and VFFT and also with literature

  15. Elastic and inelastic scattering of 240-MeV {sup 6}Li ions from {sup 40}Ca and {sup 48}Ca and tests of a systematic optical potential

    SciTech Connect

    Krishichayan,; Chen, X.; Lui, Y.-W.; Button, J.; Youngblood, D. H. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)

    2010-04-15

    Elastic and inelastic scattering of 240-MeV {sup 6}Li particles from {sup 40}Ca and {sup 48}Ca were measured with the multipole-dipole-multipole spectrometer from 4 deg. <=theta{sub c.m.}<=40 deg. Optical potential parameters were obtained by fitting the elastic-scattering data with the double-folding model using the density-dependent M3Y NN effective interaction and B(E2) and B(E3) values obtained for low-lying 2{sup +} and 3{sup -} states agreed with the adopted values. The results are compared with those obtained using potentials derived from the systematics of potentials previously obtained for {sup 24}Mg, {sup 28}Si, {sup 58}Ni, and {sup 90}Zr. Cross sections for excitation of giant resonances were also calculated with the potentials obtained.

  16. A balance between membrane elasticity and polymerization energy sets the shape of spherical clathrin coats

    NASA Astrophysics Data System (ADS)

    Saleem, Mohammed; Morlot, Sandrine; Hohendahl, Annika; Manzi, John; Lenz, Martin; Roux, Aurélien

    2015-02-01

    In endocytosis, scaffolding is one of the mechanisms to create membrane curvature by moulding the membrane into the spherical shape of the clathrin cage. However, the impact of membrane elastic parameters on the assembly and shape of clathrin lattices has never been experimentally evaluated. Here, we show that membrane tension opposes clathrin polymerization. We reconstitute clathrin budding in vitro with giant unilamellar vesicles (GUVs), purified adaptors and clathrin. By changing the osmotic conditions, we find that clathrin coats cause extensive budding of GUVs under low membrane tension while polymerizing into shallow pits under moderate tension. High tension fully inhibits polymerization. Theoretically, we predict the tension values for which transitions between different clathrin coat shapes occur. We measure the changes in membrane tension during clathrin polymerization, and use our theoretical framework to estimate the polymerization energy from these data. Our results show that membrane tension controls clathrin-mediated budding by varying the membrane budding energy.

  17. Computed potential energy surfaces for chemical reactions

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.

    1994-01-01

    Quantum mechanical methods have been used to compute potential energy surfaces for chemical reactions. The reactions studied were among those believed to be important to the NASP and HSR programs and included the recombination of two H atoms with several different third bodies; the reactions in the thermal Zeldovich mechanism; the reactions of H atom with O2, N2, and NO; reactions involved in the thermal De-NO(x) process; and the reaction of CH(squared Pi) with N2 (leading to 'prompt NO'). These potential energy surfaces have been used to compute reaction rate constants and rates of unimolecular decomposition. An additional application was the calculation of transport properties of gases using a semiclassical approximation (and in the case of interactions involving hydrogen inclusion of quantum mechanical effects).

  18. Energy saving potential of office equipment power management

    Microsoft Academic Search

    Kaoru Kawamoto; Yoshiyuki Shimoda; Minoru Mizuno

    2004-01-01

    While many studies have estimated the energy saving potential of office equipment power management, there is no recent study about the energy saving potential of shortening the power management delay time. In this paper, we estimated the energy saving potential of the complete saturation of power management, and also the additional energy saving potential of shortening the power management delay

  19. Prospects in Constraining the Dark Energy Potential

    E-print Network

    Fernandez-Martinez, Enrique

    2008-01-01

    We generalize to non-flat geometries the formalism of Simon et al. (2005) to reconstruct the dark energy potential. This formalism makes use of quantities similar to the Horizon-flow parameters in inflation, can, in principle, be made non-parametric and is general enough to be applied outside the simple, single scalar field quintessence. Since presently available and forthcoming data do not allow a non-parametric and exact reconstruction of the potential, we consider a general parametric description in term of Chebyshev polynomials. We then consider present and future measurements of H(z), Baryon Acoustic Oscillations surveys and Supernovae type 1A surveys, and investigate their constraints on the dark energy potential. We find that, relaxing the flatness assumption increases the errors on the reconstructed dark energy evolution but does not open up significant degeneracies, provided that a modest prior on geometry is imposed. Direct measurements of H(z), such as those provided by BAO surveys, are crucially i...

  20. Wave energy transfer in elastic half-spaces with soft interlayers.

    PubMed

    Glushkov, Evgeny; Glushkova, Natalia; Fomenko, Sergey

    2015-04-01

    The paper deals with guided waves generated by a surface load in a coated elastic half-space. The analysis is based on the explicit integral and asymptotic expressions derived in terms of Green's matrix and given loads for both laminate and functionally graded substrates. To perform the energy analysis, explicit expressions for the time-averaged amount of energy transferred in the time-harmonic wave field by every excited guided or body wave through horizontal planes and lateral cylindrical surfaces have been also derived. The study is focused on the peculiarities of wave energy transmission in substrates with soft interlayers that serve as internal channels for the excited guided waves. The notable features of the source energy partitioning in such media are the domination of a single emerging mode in each consecutive frequency subrange and the appearance of reverse energy fluxes at certain frequencies. These effects as well as modal and spatial distribution of the wave energy coming from the source into the substructure are numerically analyzed and discussed. PMID:25920833

  1. Cross sections for neutron-deuteron elastic scattering in the energy range 135-250 MeV

    E-print Network

    E. Ertan; T. Akdogan; M. B. Chtangeev; W. A. Franklin; P. A. M. Gram; M. A. Kovash; J. L. Matthews; M. Yuly

    2012-11-22

    We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from $80^\\circ$ to $130^\\circ$. Cross sections for neutron-proton elastic scattering were also measured with the same experimental setup for normalization purposes. Our $nd$ cross section results are compared with predictions based on Faddeev calculations including three-nucleon forces, and with cross sections measured with charged particle and neutron beams at comparable energies.

  2. The Wind Energy Potential of Iceland

    NASA Astrophysics Data System (ADS)

    Nawri, Nikolai; Nína Petersen, Guðrún; Bjornsson, Halldór; Hahmann, Andrea N.; Jónasson, Kristján; Bay Hasager, Charlotte; Clausen, Niels-Erik

    2014-05-01

    While Iceland has an abundant wind energy resource, its use for electrical power production has so far been limited. Electricity in Iceland is generated primarily from hydro- and geothermal sources, and adding wind energy has so far not been considered practical or even necessary. However, wind energy is becoming a more viable option, as opportunities for new hydro- or geothermal power installations become limited. In order to obtain an estimate of the wind energy potential of Iceland, a wind atlas has been developed as part of the joint Nordic project 'Improved Forecast of Wind, Waves and Icing' (IceWind). Downscaling simulations performed with the Weather Research and Forecasting (WRF) model were used to determine the large-scale wind energy potential of Iceland. Local wind speed distributions are represented by Weibull statistics. The shape parameter across Iceland varies between 1.2 and 3.6, with the lowest values indicative of near-exponential distributions at sheltered locations, and the highest values indicative of normal distributions at exposed locations in winter. Compared with summer, average power density in winter is increased throughout Iceland by a factor of 2.0 - 5.5. In any season, there are also considerable spatial differences in average wind power density. Relative to the average value within 10 km of the coast, power density across Iceland varies between 50 - 250%, excluding glaciers, or between 300 - 1500 W m-2 at 50 m above ground level in winter. At intermediate elevations of 500 - 1000 m above mean sea level, power density is independent of the distance to the coast. In addition to seasonal and spatial variability, differences in average wind speed and power density also exist for different wind directions. Along the coast in winter, power density of onshore winds is higher by 100 - 700 W m-2 than that of offshore winds. The regions with the highest average wind speeds are impractical for wind farms, due to the distances from road infrastructure and the power grid, as well as due to the harsh winter climate. However, even in easily accessible regions, wind energy potential in Iceland, as measured by annual average power density, is among the highest in Western Europe. Based on these results, 14 test sites were selected for more detailed analyses using the Wind Atlas Analysis and Application Program (WAsP). These calculations show that a modest wind farm of ten medium size turbines would produce more energy throughout the year than a small hydro power plant, making wind energy a viable additional option.

  3. Analyzing power for p elastic scattering in the energy region of the Roper resonance

    SciTech Connect

    Mokhtari, A.; Briscoe, W.J.; Eichon, A.D.; Fitzgerald, D.H.; Kim, G.J.; Nefkens, B.M.K.; Wightman, J.A.; Sadler, M.E.

    1986-01-01

    High-precision measurements of the analyzing power A/sub N/ in p elastic scattering at p/sub / = 471--687 MeV/c are presented and compared with the results of recent N partial-wave analyses (PWA's) by the Karlsruhe-Helsinki, CMU-LBL, and VPI groups. While agreeing with the main features of the measured angular dependence of A/sub N/, the three PWA's yield larger values than the measurements at forward angles at p/sub / = 471, 547, and 625 MeV/c. At 687 MeV/c the PWA's do not agree with the data at far backward angles. We estimate the effect of our data on the phase shifts in this energy region, which includes the Roper resonance.

  4. Backward asymmetry measurements in the elastic pion-proton scattering at resonance energies

    NASA Astrophysics Data System (ADS)

    Alekseev, I. G.; Bazhanov, N. A.; Beloglazov, Yu. A.; Budkovsky, P. E.; Bunyatova, E. I.; Filimonov, E. A.; Kanavets, V. P.; Kovalev, A. I.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Shchedrov, V. A.; Sulimov, A. D.; Sumachev, V. V.; Svirida, D. N.; Trautman, V. Yu.; Zolin, L. S.

    2009-02-01

    The asymmetry parameter P was measured for the elastic pion-proton scattering in the very backward angular region of ?_{CM}^{} ? 150 - 170° at several pion beam energies in the invariant-mass range containing most of the pion-proton resonances. The general goal of the experimental program was to provide new data for partial wave analyses in order to resolve their uncertainties in the baryon resonance region to allow the unambiguous baryon spectrum reconstructions. Until recently the parameter P was not measured in the examined domain that might be explained by the extremely low cross-section. At the same time the predictions of various partial wave analyses are far from agreement in some kinematic areas and specifically those areas were chosen for the measurements where the disagreement is most pronouncing. The experiment was performed at the ITEP U-10 proton synchrotron, Moscow, by the ITEP-PNPI Collaboration in the latest 5 years.

  5. Elastic energy and string configurations in the chiral gauge theory of biaxial uniaxial nematic phase transitions

    E-print Network

    L. V. Elnikova

    2014-10-09

    In nematic liquid crystals (NLCs), topological defects of a chiral origin play a role in phase transitions and lead to phase configurations of nontrivial topology, like those in neutron stars and helium in the A-phase. In the biaxial-uniaxial phase transition, the deformation of the orbit, as the order parameter degeneracy of the NLC, connects together an evolution of topological defects, the surface anchoring energy and elastic Frank modui. In this work we estimate the chiral gauge field presentation of the constrained Ladnau-de Gennes theory of the biaxial nematics, which have to explain their topologically dependent phase transformation, using the description of the transformation of disclinations in the biaxial nematic phase into the surface bojooms of a uniaxial NLC.

  6. Computed potential energy surfaces for chemical reactions

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.; Levin, Eugene

    1993-01-01

    A new global potential energy surface (PES) is being generated for O(P-3) + H2 yields OH + H. This surface is being fit using the rotated Morse oscillator method, which was used to fit the previous POL-CI surface. The new surface is expected to be more accurate and also includes a much more complete sampling of bent geometries. A new study has been undertaken of the reaction N + O2 yields NO + O. The new studies have focused on the region of the surface near a possible minimum corresponding to the peroxy form of NOO. A large portion of the PES for this second reaction has been mapped out. Since state to state cross sections for the reaction are important in the chemistry of high temperature air, these studies will probably be extended to permit generation of a new global potential for reaction.

  7. Theoretical studies of potential energy surfaces.

    SciTech Connect

    Harding, L. B. (Chemical Sciences and Engineering Division)

    2008-01-01

    The goal of this program is to calculate accurate potential energy surfaces for both reactive and nonreactive systems. To do this the electronic Schroedinger equation must be solved. Our approach starts with multiconfiguration self-consistent field (MCSCF) reference wave functions. These reference wavefunctions are designed to be sufficiently flexible to accurately describe changes in electronic structure over a broad range of geometries. Dynamical electron correlation effects are included via multireference, singles and doubles configuration interaction (MRCI) calculations. With this approach, we are able to provide chemically useful predictions of the energetics for many systems. A second aspect of this program is the development of techniques to fit multi-dimensional potential surfaces to convenient, global, analytic functions that can then be used in dynamics calculations.

  8. Elastic scattering of low-energy electrons by 1,4-dioxane

    SciTech Connect

    Barbosa, Alessandra Souza; Bettega, Márcio H. F., E-mail: bettega@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba, Paraná (Brazil)] [Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba, Paraná (Brazil)

    2014-05-14

    We report calculated cross sections for elastic collisions of low-energy-electrons with 1,4-dioxane. Our calculations employed the Schwinger multichannel method with pseudopotentials and were carried out in the static-exchange and static-exchange plus polarization approximations for energies up to 30 eV. Our results show the presence of three shape resonances belonging to the B{sub u}, A{sub u}, and B{sub g} symmetries and located at 7.0 eV, 8.4 eV, and 9.8 eV, respectively. We also report the presence of a Ramsauer-Townsend minimum located at around 0.05 eV. We compare our calculated cross sections with experimental data and R-matrix and independent atom model along with the additivity rule corrected by using screening coefficients theoretical results for 1,4-dioxane obtained by Palihawadana et al. [J. Chem. Phys. 139, 014308 (2013)]. The agreement between the present and the R-matrix theoretical calculations of Palihawadana et al. is relatively good at energies below 10 eV. Our calculated differential cross sections agree well with the experimental data, showing only some discrepancies at higher energies.

  9. Energy dependence of the optical potentials for the 9Be +208Pb and 9Be +209Bi systems at near-Coulomb-barrier energies

    NASA Astrophysics Data System (ADS)

    Gómez Camacho, A.; Yu, N.; Zhang, H. Q.; Gomes, P. R. S.; Jia, H. M.; Lubian, J.; Lin, C. J.

    2015-04-01

    We analyze the energy dependence of the interacting optical potential, at near barrier energies, for two systems involving the weakly bound projectile 9Be and the heavy 208Pb and 209Bi targets, by the simultaneous fit of elastic scattering angular distributions and fusion excitation functions. The approach used consists of dividing the optical potential into two parts. A short-range potential VF+i WF that is responsible for fusion, and a superficial potential VDR+i WDR for direct reactions. It is found, for both systems studied, that the fusion imaginary potential WF presents the usual threshold anomaly (TA) observed in tightly bound systems, whereas the direct reaction imaginary potential WDR shows a breakup threshold anomaly (BTA) behavior. Both potentials satisfy the dispersion relation. The direct reaction polarization potential predominates over the fusion potential and so a net overall behavior is found to follow the BTA phenomenon.

  10. A new representation for the strain energy of anisotropic elastic materials with application to damage evolution in brittle materials

    Microsoft Academic Search

    D. Elata; M. B. Rubin

    1995-01-01

    In this paper, we develop a new representation of the strain energy of an elastic material using twenty-one scalar measures of strain. These measures are associated with material line elements which are directed along the six axes of symmetry of a regular icosahedron, and they include: six measures of axial strain and fifteen measures of the angular strain. When the

  11. Determining Equilibrium Structures and Potential Energy Functions for

    E-print Network

    Le Roy, Robert J.

    Chapter 6 Determining Equilibrium Structures and Potential Energy Functions for Diatomic Molecules also to determine accurate potential energy functions spanning the whole potential energy well. The traditional way of doing this involves first determining the v-dependence of the vibrational level energies Gv

  12. Metabolic energy cost of action potential velocity.

    PubMed

    Crotty, Patrick; Sangrey, Thomas; Levy, William B

    2006-09-01

    The action potential of the unmyelinated nerve is metabolically expensive. Using the energetic cost per unit length for the biophysically modeled action potential of the squid giant axon, we analyze this cost and identify one possible optimization. The energetic cost arising from an action potential is divided into three separate components: 1) the depolarization of the rising phase; 2) the hyperpolarization of the falling phase; and 3) the largest component, the overlapping of positive and negative currents, which has no electrical effect. Using both the Hodgkin-Huxley (HH) model and an improved version of the HH model (HHSFL), we investigate the variation of these three components as a function of easily evolvable parameters, axon diameter and ion channel densities. Assuming conduction velocity is well designed for each organism, the energy component associated with the rising phase attains a minimum near the biological values of the diameter and channel densities. This optimization is explained by the membrane capacitance per unit length. The functional capacitance is the sum of the intrinsic membrane capacitance and the gating capacitance associated with the sodium channel, and this capacitance minimizes at nearly the same values of diameter and channel density. Because capacitance is temperature independent and because this result is independent of the assumed velocity, the result generalizes to unmyelinated mammalian axons. That is, channel density is arguably an evolved property that goes hand-in-hand with the evolutionary stability of the sodium channel. PMID:16554507

  13. Energy potential of leafy spurge (Euphorbia esula)

    SciTech Connect

    Maxwell, B.D.; Wiatr, S.M.; Fay, P.K.

    1985-01-01

    Leafy spurge (Euphorbia esula) is a noxious, perennial weed that infests pastures, range land and waste areas in the northern Great Plains. The objective of this study was to determine the productive potential of this species when grown under optimum agronomic conditions. Plants were fertilized and irrigated. Oil, hydrocarbon, total protein, and dry-weight production were measured on 3 harvest dates. Calorimetric analyses were performed to determine the potential of leafy spurge as a fuel crop. The hydrocarbon content of 12 strains of leafy spurge was determined to measure genetic variability for this trait. The addition of fertilizer doubled dry-weight production but did not affect percent oil or hydrocarbon content. Oil and hydrocarbon production averaged 6.8 and 0.6% on a plant dry-weight basis. Maximum production of plant biomass, protein, and hydrocarbon was obtained from a mid-July harvest. Oil content increased later in the growing season. The total protein content of leafy spurge averaged 12%. Whole-plant biomass had a caloric value of 4407 cal/g while the oils contained 10,019 cal/g. Leafy spurge hay can produce 4 times more energy per year than wheat straw; therefore, the immediate potential of leafy spurge whole-plant biomass as a locally grown fuel crop for home-heating purposes is suggested.

  14. Precision Pion-Proton Elastic Differential Cross Sections at Energies Spanning the Delta Resonance

    E-print Network

    M. M. Pavan; J. T. Brack; F. Duncan; A. Feltham; G. Jones; J. Lange; K. J. Raywood; M. E. Sevior; R. Adams; D. F. Ottewell; G. R. Smith; B. Wells; R. L. Helmer; E. L. Mathie; R. Tacik; R. A. Ristinen; I. I. Strakovsky; H-M. Staudenmaier

    2001-03-15

    A precision measurement of absolute pi+p and pi-p elastic differential cross sections at incident pion laboratory kinetic energies from T_pi= 141.15 to 267.3 MeV is described. Data were obtained detecting the scattered pion and recoil proton in coincidence at 12 laboratory pion angles from 55 to 155 degrees for pi+p, and six angles from 60 to 155 degrees for pi-p. Single arm measurements were also obtained for pi+p energies up to 218.1 MeV, with the scattered pi+ detected at six angles from 20 to 70 degrees. A flat-walled, super-cooled liquid hydrogen target as well as solid CH2 targets were used. The data are characterized by small uncertainties, ~1-2% statistical and ~1-1.5% normalization. The reliability of the cross section results was ensured by carrying out the measurements under a variety of experimental conditions to identify and quantify the sources of instrumental uncertainty. Our lowest and highest energy data are consistent with overlapping results from TRIUMF and LAMPF. In general, the Virginia Polytechnic Institute SM95 partial wave analysis solution describes our data well, but the older Karlsruhe-Helsinki PWA solution KH80 does not.

  15. Dislocations and crowdions in two-dimensional crystals. II. Elastic fields and intrinsic energies in a 2D hexagonal lattice

    NASA Astrophysics Data System (ADS)

    Natsik, V. D.; Smirnov, S. N.

    2015-03-01

    The fields of elastic deformation and stress around the centers of dislocations and crowdions in 2D crystals with isotropic elastic properties are described in the continuum approximation. The elastic energy of both types of defects was calculated and its dependence on crystal size was discussed. Considered also was the quantitative uncertainty associated with the inapplicability of the continual description of deformation at atomic distances from the centers of the defects. The results obtained by using the continuum theory were further improved by comparing with the results of numerical analysis using the methods of molecular dynamics of atomic structure of dislocations and crowdions in a hexagonal 2D crystal. The present work continues the study that was commenced in the previous paper (Fiz. Nizk. Temp. 40, 1366 (2014)).

  16. Energy potential of sugarcane and sweet sorghum

    SciTech Connect

    Elawad, S.H.; Gascho, G.J.; Shih, S.F.

    1980-01-01

    The potential of sugarcane and sweet sorghum as raw materials for the production of ethanol and petrochemical substitutes is discussed. Both crops belong to the grass family and are classified as C/sub 4/ malateformers which have the highest rate of photosynthesis among terrestrial plants. Large amounts of biomass are required to supply a significant fraction of US energy consumption. Biomass production could be substantially increased by including tops and leaves, adopting narrow row spacing and improving cultural practices. This presents challenges for cultivating, harvesting, and hauling the biomass to processing centers. Large plants and heavy capital investment are essential for energy production. Ethanol and ammonia are the most promising candidates of a biomass program. If sugarcane were to be used for biomass production, breeding programs should be directed for more fermentable sugars and fiber. Energy research on sweet sorghum should be done with syrup varieties. Sweet sorghum needs to be incorporated with other crops because of its short growing season. The disposal of stillage from an extensive ethanol industry may pose environmental problems.

  17. Prediction of intermediate-energy neutron scattering observables from a Dirac optical potential

    NASA Astrophysics Data System (ADS)

    Kozack, R.; Madland, D. G.

    1990-03-01

    We construct a global optical potential for intermediate-energy nucleon + 208Pb scattering using the Dirac phenomenology. Experimental proton elastic differential cross sections, analyzing powers, spin-rotation functions, total reaction cross sections, and neutron total cross sections are used to construct a Dirac potential spanning an energy range of 95 to 300 MeV. Calculations of n + 208Pb scattering observables are performed and significant differences with predictions and measurements of the corresponding proton scattering observables are found. The origins of the differences are explored by performing calculations using a "gedanken" projectile. The predicted neutron observables are as yet unmeasured and thus have relevance for the newly-constructed intermediate-energy neutron beam facilities.

  18. Induced Seismicity Potential of Energy Technologies

    NASA Astrophysics Data System (ADS)

    Hitzman, Murray

    2013-03-01

    Earthquakes attributable to human activities-``induced seismic events''-have received heightened public attention in the United States over the past several years. Upon request from the U.S. Congress and the Department of Energy, the National Research Council was asked to assemble a committee of experts to examine the scale, scope, and consequences of seismicity induced during fluid injection and withdrawal associated with geothermal energy development, oil and gas development, and carbon capture and storage (CCS). The committee's report, publicly released in June 2012, indicates that induced seismicity associated with fluid injection or withdrawal is caused in most cases by change in pore fluid pressure and/or change in stress in the subsurface in the presence of faults with specific properties and orientations and a critical state of stress in the rocks. The factor that appears to have the most direct consequence in regard to induced seismicity is the net fluid balance (total balance of fluid introduced into or removed from the subsurface). Energy technology projects that are designed to maintain a balance between the amount of fluid being injected and withdrawn, such as most oil and gas development projects, appear to produce fewer seismic events than projects that do not maintain fluid balance. Major findings from the study include: (1) as presently implemented, the process of hydraulic fracturing for shale gas recovery does not pose a high risk for inducing felt seismic events; (2) injection for disposal of waste water derived from energy technologies does pose some risk for induced seismicity, but very few events have been documented over the past several decades relative to the large number of disposal wells in operation; and (3) CCS, due to the large net volumes of injected fluids suggested for future large-scale carbon storage projects, may have potential for inducing larger seismic events.

  19. Elastic free-energy of wormlike micellar chains: theory and suggested experiments

    E-print Network

    Meisam Asgari

    2015-02-09

    The extensive application of surfactants motivates comprehensive and predictive theoretical studies that improve our understanding of the behaviour of these complex systems. In this study, an expression for the elastic free-energy density of a wormlike micellar chain is derived taking into account interactions between its constituent molecules. The resulting expression incorporates the sum of a quadratic term in the curvature and a quadratic term in the torsion of the centerline of wormlike micelle and thus resembles free-energy density functions for polymer chains and DNA available in the literature. The derived model is applied on a wormlike micelle in the shape of a circular arc, open or closed. A detailed application of the derived model on wormlike micelles of toroidal shape, along with employing necessary statistical-thermodynamical concepts of self-assembly, is performed, and the results are found to be consistent with the ones available in the literature. Steps towards obtaining the material parameters through experiments are suggested and discussed.

  20. Bohm's quantum potential as an internal energy

    NASA Astrophysics Data System (ADS)

    Dennis, Glen; de Gosson, Maurice A.; Hiley, Basil J.

    2015-06-01

    We pursue our discussion of Fermi's surface initiated by Dennis, de Gosson and Hiley and show that Bohm's quantum potential can be viewed as an internal energy of a quantum system, giving further insight into its role in stationary states. This implies that the 'particle' referred to in Bohm's theory is not a classical point-like object but rather has an extended structure in phase space which can be linked to the notion of a symplectic capacity, a topological feature of the underlying symplectic geometry. This structure provides us with a new, physically motivated derivation of Schrödinger's equation provided we interpret Gleason's theorem as a derivation of the Born rule from fundamental assumptions about quantum probabilities.

  1. Certification and the potential energy landscape.

    PubMed

    Mehta, Dhagash; Hauenstein, Jonathan D; Wales, David J

    2014-06-14

    Typically, there is no guarantee that a numerical approximation obtained using standard nonlinear equation solvers is indeed an actual solution, meaning that it lies in the quadratic convergence basin. Instead, it may lie only in the linear convergence basin, or even in a chaotic region, and hence not converge to the corresponding stationary point when further optimization is attempted. In some cases, these non-solutions could be misleading. Proving that a numerical approximation will quadratically converge to a stationary point is termed certification. In this report, we provide details of how Smale's ?-theory can be used to certify numerically obtained stationary points of a potential energy landscape, providing a mathematical proof that the numerical approximation does indeed correspond to an actual stationary point, independent of the precision employed. PMID:24929381

  2. Vanishing rainbows near orbiting and the energy dependence of rainbow scattering - Relation to properties of the potential. [molecular beam scattering cross sections

    NASA Technical Reports Server (NTRS)

    Greene, E. F.; Hall, R. B.; Mason, E. A.

    1975-01-01

    The energy threshold behavior of elastic rainbow scattering near the transition to orbiting is derived. Analysis of the energy dependence of the rainbow angle shows that the full range from high energies down to orbiting can be fitted with two parameters. Thus, measurements of the rainbow angle can give essentially only two pieces of information about the potential. For potentials of common shapes, such measurements are sensitive to regions of the potential just beyond the minimum and give information about the shape of the potential in this range. However, neither a minimum nor a point of inflection in the potential is necessary for rainbow scattering.

  3. Formal definition of POTENTIAL ENERGY (valid for conservative forces only)

    E-print Network

    page - 16 Formal definition of POTENTIAL ENERGY (valid for conservative forces only) Given one type of conservative force F UB - UA= - = - Definition of 'Potential energy difference" conserv #12;page - 17 the definition of the "potential energy difference UB - UA " as equal to negative value of the work W done

  4. Elastic and other associated properties of C60

    Microsoft Academic Search

    R. Venkatesh; R. V. Gopala Rao

    1997-01-01

    Considering that Coulomb interactions contribute a negligible amount to the cohesive energy in C60, which has an fcc structure at room temperature, we used Girifalco potential function in our calculations; C60 is spherical in nature and rotates rather freely at room temperature. From this potential we evaluated the second-order elastic constants (SOEC's), their pressure derivatives, and the third-order elastic constants

  5. Computed potential energy surfaces for chemical reactions

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.

    1988-01-01

    The minimum energy path for the addition of a hydrogen atom to N2 is characterized in CASSCF/CCI calculations using the (4s3p2d1f/3s2p1d) basis set, with additional single point calculations at the stationary points of the potential energy surface using the (5s4p3d2f/4s3p2d) basis set. These calculations represent the most extensive set of ab initio calculations completed to date, yielding a zero point corrected barrier for HN2 dissociation of approx. 8.5 kcal mol/1. The lifetime of the HN2 species is estimated from the calculated geometries and energetics using both conventional Transition State Theory and a method which utilizes an Eckart barrier to compute one dimensional quantum mechanical tunneling effects. It is concluded that the lifetime of the HN2 species is very short, greatly limiting its role in both termolecular recombination reactions and combustion processes.

  6. Elastic Circuits

    Microsoft Academic Search

    Josep Carmona; Jordi Cortadella; Michael Kishinevsky; Alexander Taubin

    2009-01-01

    Elasticity in circuits and systems provides tolerance to variations in computation and communication delays. This paper presents a comprehensive overview of elastic circuits for those designers who are mainly familiar with synchronous design. Elasticity can be implemented both synchronously and asynchronously, although it was traditionally more often associated with asynchronous circuits. This paper shows that synchronous and asynchronous elastic circuits

  7. Valence force field theory, elastic, acoustic and thermodynamic properties and a potential function of TeO 2 glass

    Microsoft Academic Search

    R. V Gopala Rao; R Venkatesh

    2003-01-01

    A short survey has been made on the extensive work that is being done on the pressure derivatives of the second order elastic constants (SOEC) to ascertain various properties of substances. Hence an attempt has been made to correlate the pressure derivatives to some properties of the substances. Thus some equations have been derived to correlate the Grüneisen parameter which

  8. Estimating the Potential Impact of Renewable Energy on the Caribbean

    E-print Network

    Kammen, Daniel M.

    Estimating the Potential Impact of Renewable Energy on the Caribbean Job Sector Rebekah Shirley renewable energy projects within the Caribbean region. We present a model scenario where together energy

  9. The potential energy surface of isomerising disilyne.

    PubMed

    Law, Mark M; Fraser-Smith, Jonathan T; Perotto, Carlo U

    2012-04-17

    A (semi-)global, analytical potential energy surface is reported for the ground electronic state of the isomerising disilyne molecule, Si(2)H(2). The surface reproduces well ab initio energies calculated at the CCSD(T) level with a cc-pV(Q+d)Z basis set for over 50?000 symmetrically unique molecular geometries. Of these ab initio points, 33?000 were used in a least-squares fit to determine the parameters of the analytical surface and the remainder to provide an independent test/validation set. The fitted surface includes: the four known isomeric forms of disilyne, dibridged, monobridged, disilavinylidene and trans-bent; the three most important transition states and four other critical points. The surface reproduces accurately existing experimental spectroscopic data for the dibridged and monobridged isomers and predictions are made for the disilavinylidene and trans-bent forms. The surface has the correct symmetry properties with respect to permutation of like atoms and is suitable for detailed dynamics studies of the isomerising Si(2)H(2) system. Also reported is a systematic investigation of the critical points using the CCSD(T) and MRCI methods and basis sets up to 6-zeta quality: the effects of core-correlation, augmentation with diffuse functions and tight-d functions have been studied. The basis sets include the correlation consistent core-valence, cc-pCV(n+d)Z, basis sets recently developed by Yockel and Wilson [Theor. Chem. Acc., 2008, 120, 119]. Very good agreement is obtained between the theoretical and experimental equilibrium geometries, rotational constants and three available vibration frequencies for the dibridged isomer and for the rotational constants of the monobridged isomer. Multireference character, as measured by the T(1) diagnostic, is found to vary significantly across the 12 critical points investigated. PMID:22511004

  10. Elastic internal flywheel gimbal

    SciTech Connect

    Rabenhorst, D.W.

    1981-01-13

    An elastic joint mounting and rotatably coupling a rotary inertial energy storage device or flywheel, to a shaft, the present gimbal structure reduces vibration and shock while allowing precession of the flywheel without the need for external gimbal mounts. The present elastic joint usually takes the form of an annular elastic member either integrally formed into the flywheel as a centermost segment thereof or attached to the flywheel or flywheel hub member at the center thereof, the rotary shaft then being mounted centrally to the elastic member.

  11. How well do we understand quasi-elastic reactions at energies close to the barrier

    SciTech Connect

    Rehm, K.E.

    1988-01-01

    In collisions between too heavy nuclei a wide spectrum of different reaction modes is observed covering the range from simple processes like elastic scattering to complicated multistep transfers and fusion. On the theoretical side heavy ion reactions are usually analyzed using models that were developed first for light ion induced reactions: the optical model for elastic scattering and the DWBA for more inelastic processes like transfer and inelastic scattering. Some of the assumptions going into these approximations, however, are not valid for heavy ion induced reactions. The region between fusion and quasi-elastic reactions is not well understood theoretically. This region is associated with deep inelastic collisions, which are complex multiparticle reactions involving transfer of several protons and neutrons. In this paper, the author discusses to what extent experiments in the field of quasi-elastic scattering are understood within the framework of various theoretical models and in what areas more work is needed.

  12. Renewable energy costs, potentials, barriers: Conceptual issues

    Microsoft Academic Search

    Aviel Verbruggen; Manfred Fischedick; William Moomaw; Tony Weir; Alain Nadaï; Lars J. Nilsson; John Nyboer; Jayant Sathaye

    2010-01-01

    Renewable energy can become the major energy supply option in low-carbon energy economies. Disruptive transformations in all energy systems are necessary for tapping widely available renewable energy resources. Organizing the energy transition from non-sustainable to renewable energy is often described as the major challenge of the first half of the 21st century. Technological innovation, the economy (costs and prices) and

  13. Measurements of the energy dependence of the analyzing power in pp elastic scattering in the CNI region

    SciTech Connect

    Bazilevsky A.; Alekseev, I.; Aschenauer, E.; Atoyan, G.; Bravar, A.; Bunce, G.; Boyle, K.; Gill, R.; Huang, H.; Lee, S.; Makdisi, Y.; Morozov, B.; Nakagawa, I.; Okada, H.; Svirida, D.; Zelenski, A.

    2010-09-27

    We present new measurements of the analyzing power A{sub N} in proton-proton elastic scattering in the Coulomb-Nuclear Interference region at {radical}s = 7.7 and 21.7 GeV obtained with the polarized atomic hydrogen jet target at RHIC. These measurements complement our earlier results at {radical}s = 6.8 and 13.7 GeV confirming the presence of a hadronic helicity flip amplitude contribution in proton-proton elastic scattering at lower energies ({radical}s <8 GeV) while higher energy data ({radical}s >13 GeV) are consistent with no hadronic helicity flip contribution.

  14. Single-wave-number representation of nonlinear energy spectrum in elastic-wave turbulence of the Föppl-von Kármán equation: Energy decomposition analysis and energy budget

    NASA Astrophysics Data System (ADS)

    Yokoyama, Naoto; Takaoka, Masanori

    2014-12-01

    A single-wave-number representation of a nonlinear energy spectrum, i.e., a stretching-energy spectrum, is found in elastic-wave turbulence governed by the Föppl-von Kármán (FvK) equation. The representation enables energy decomposition analysis in the wave-number space and analytical expressions of detailed energy budgets in the nonlinear interactions. We numerically solved the FvK equation and observed the following facts. Kinetic energy and bending energy are comparable with each other at large wave numbers as the weak turbulence theory suggests. On the other hand, stretching energy is larger than the bending energy at small wave numbers, i.e., the nonlinearity is relatively strong. The strong correlation between a mode ak and its companion mode a-k is observed at the small wave numbers. The energy is input into the wave field through stretching-energy transfer at the small wave numbers, and dissipated through the quartic part of kinetic-energy transfer at the large wave numbers. Total-energy flux consistent with energy conservation is calculated directly by using the analytical expression of the total-energy transfer, and the forward energy cascade is observed clearly.

  15. Single-wave-number representation of nonlinear energy spectrum in elastic-wave turbulence of the Föppl-von Kármán equation: energy decomposition analysis and energy budget.

    PubMed

    Yokoyama, Naoto; Takaoka, Masanori

    2014-12-01

    A single-wave-number representation of a nonlinear energy spectrum, i.e., a stretching-energy spectrum, is found in elastic-wave turbulence governed by the Föppl-von Kármán (FvK) equation. The representation enables energy decomposition analysis in the wave-number space and analytical expressions of detailed energy budgets in the nonlinear interactions. We numerically solved the FvK equation and observed the following facts. Kinetic energy and bending energy are comparable with each other at large wave numbers as the weak turbulence theory suggests. On the other hand, stretching energy is larger than the bending energy at small wave numbers, i.e., the nonlinearity is relatively strong. The strong correlation between a mode a(k) and its companion mode a(-k) is observed at the small wave numbers. The energy is input into the wave field through stretching-energy transfer at the small wave numbers, and dissipated through the quartic part of kinetic-energy transfer at the large wave numbers. Total-energy flux consistent with energy conservation is calculated directly by using the analytical expression of the total-energy transfer, and the forward energy cascade is observed clearly. PMID:25615184

  16. Effective potential for e-argon and e-krypton scattering by DCS and minimization at intermediate energies

    SciTech Connect

    Paikeday, J.M.

    1999-12-01

    The differential scattering cross section (DCS) for electrons scattered elastically by argon and krypton atoms is studied using a model potential. In the present study, the long-range polarization potential is represented by an energy-dependent function and the short-range part is constructed from the nonrelativistic Hartree-Fock wave function of the target atom. The computed differential cross section obtained using the approximate effective interaction potential for electrons scattered by neon and argon atoms in their ground state is compared with available published results. In the present study, the parameters contained in the energy-dependent effective potential are determined by the minimization of the DCS with respect to angle {theta} and the incident energy. The resulting DCS in the angular range 2{degree} {lt} {theta} {lt} 178{degree} is found to be in good agreement with the available experimental and theoretical results in the intermediate energy range.

  17. Effective potential for e-neon and e-argon scattering by DCS minimization at intermediate energies

    SciTech Connect

    Paikeday, J.M.; Longstreet, A. [Southeast Missouri State Univ., Cape Girardeau, MO (United States)] [Southeast Missouri State Univ., Cape Girardeau, MO (United States)

    1998-11-01

    The differential scattering cross-section (DCS) for electrons scattered elastically by neon and argon atoms is studied using a model potential. In the present study the long-range polarization potential is represented by an energy-dependent function, and the short-range part is constructed from the nonrelativistic Hartree-Fock wave function of the target atom. The computed differential cross section obtained using the approximate effective interaction potential for electrons scattered by neon and argon atoms in their ground state is compared with available published results. In the present study the parameters contained in the energy-dependent effective potential are determined by the minimization of the DCS with respect to angle {theta} and the incident energy. The resulting DCS in the angular range 2{degree} < {theta} < 178{degree} is found to be in good agreement with the available experimental and theoretical results in the intermediate energy range.

  18. Ab initio potential energy surfaces and nonadiabatic collision dynamics in H(+)+O(2) system.

    PubMed

    Amaran, Saieswari; Kumar, Sanjay

    2008-04-21

    The adiabatic potential energy surfaces for the lowest five electronic states of (3)A" symmetry for the H(+)+O(2) collision system have been obtained at the multireference configuration interaction level of accuracy using Dunning's correlation consistent polarized valence triple zeta basis set. The radial nonadiabatic coupling terms and the mixing angle between the lowest two electronic states (1 (3)A" and 2 (3)A"), which adiabatically correlate in the asymptotic limit to H((2)S)+O(2) (+)(X (2)Pi(g)) and H(+)+O(2)(X (3)Sigma(g)(-)), respectively, have been computed using ab initio procedures at the same level of accuracy to yield the corresponding quasidiabatic potential energy matrix. The computed strengths of the vibrational coupling matrix elements reflect the trend observed for inelastic vibrational excitations of O(2) in the experiments at collision energy of 9.5 eV. The quantum dynamics has been preformed on the newly obtained coupled quasidiabatic potential energy surfaces under the vibrational close-coupling rotational infinite-order sudden framework at the experimental collision energy of 9.5 eV. The present theoretical results for vibrational elastic/inelastic excitations of O(2) are in overall good agreement with the available experimental data obtained from the proton energy-loss spectra in molecular beam experiments [F. A. Gianturco et al., J. Phys. B 14, 667 (1981)]. The results for the complementary charge transfer processes are also presented at this collision energy. PMID:18433227

  19. Influence of high-energy impact actions on the elastic and anelastic properties of martensitic Cu–Al–Ni crystals

    Microsoft Academic Search

    Yu Emel’lyanov; S Golyandin; N. P Kobelev; S Kustov; S Nikanorov; G Pugachev; K Sapozhnikov; A Sinani; Ya. M Soifer; J Van Humbeeck; R De Batist

    2000-01-01

    The influence of high-energy impact shock-wave loading on the microplasticity and macroscopic performance of the Cu–Al–Ni crystals in the ?1? martensitic phase has been studied. Elastic and anelastic properties of quenched and aged polyvariant single crystals before and after impact shock-wave loading were measured in the temperature range 80–300 K, at a frequency of about 100 kHz in the strain

  20. Theory of evaporative cooling with energy-dependent elastic scattering cross section and application to metastable helium

    E-print Network

    Paul J. J. Tol; W. Hogervorst; W. Vassen

    2003-12-09

    The kinetic theory of evaporative cooling developed by Luiten et al. [Phys. Rev. A 53, 381 (1996)] is extended to include the dependence of the elastic scattering cross section on collision energy. We introduce a simple approximation by which the transition range between the low-temperature limit and the unitarity limit is described as well. Applying the modified theory to our measurements on evaporative cooling of metastable helium we find a scattering length |a| = 10(5) nm.

  1. Theory of evaporative cooling with energy-dependent elastic scattering cross section and application to metastable helium

    SciTech Connect

    Tol, Paul J.J.; Hogervorst, Wim; Vassen, Wim [Laser Centre Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands)

    2004-07-01

    The kinetic theory of evaporative cooling developed by Luiten et al. [Phys. Rev. A 53, 381 (1996)] is extended to include the dependence of the elastic scattering cross section on collision energy. We introduce a simple approximation by which the transition range between the low-temperature limit and the unitarity limit is described as well. Applying the modified theory to our measurements on evaporative cooling of metastable helium, we find a scattering length a=10(5) nm.

  2. Elastic and vibrationally inelastic cross sections and energy loss spectra for electron collisions with GeH4

    Microsoft Academic Search

    M. A. Dillon; L. Boesten; H. Tanaka; M. Kimura; H. Sato

    1993-01-01

    Absolute vibrationally elastic cross sections for e-GeH4 collisions have been determined for electrons of 1, 2, 2.5, 3, 5, 7.5, 10, 15, 20, 60 and 100 eV incidence energy over a scattering angular range of 10 degrees -130 degrees . The observed angular distributions correspond, at least qualitatively, to theoretical formulations using the continuum-multiple-scattering method, the parameter-free static-exchange-polarization approximation, and

  3. Potential contribution of the wastewater sector to energy supply.

    PubMed

    Heubeck, S; de Vos, R M; Craggs, R

    2011-01-01

    The biological treatment of wastewater could yield high energy fuels such as methane and alcohols, however most conventional treatment systems do not recover this energy potential. with a simple model of the energy yields of various wastewater treatment technologies it is possible to demonstrate how minor shifts in technology selection can lead the industry from being identified as predominantly energy intensive, to being recognised as a source of energy resources. The future potential energy yield is estimated by applying energy yield factors to alternative use scenarios of the same wastewater loads. The method for identifying the energy potential of wastewater was demonstrated for the New Zealand wastewater sector, but can equally be applied to other countries or regions. The model suggests that by using technologies that maximise the recovery of energy from wastewater, the potential energy yield from this sector would be substantially increased (six fold for New Zealand). PMID:21866779

  4. Transportation Energy Use and Conservation Potential

    ERIC Educational Resources Information Center

    Hirst, Eric

    1973-01-01

    Analyzes transportation energy consumption and energy intensiveness for inter-city freight and passenger traffic and urban passenger traffic with the definition of energy intensiveness as Btu per ton-mile or per passenger-mile. Indicates that public education is one of three ways to achieve the goals of energy conservation. (CC)

  5. Development of global medium-energy nucleon-nucleus optical model potentials

    SciTech Connect

    Madland, D.G.; Sierk, A.J. [Los Alamos National Lab., NM (United States). Theoretical Div.

    1997-08-01

    The authors report on the development of new global optical model potentials for nucleon-nucleus scattering at medium energies. Using both Schroedinger and Dirac scattering formalisms, the goal is to construct a physically realistic optical potential describing nucleon-nucleus elastic scattering observables for a projectile energy range of (perhaps) 20 meV to (perhaps) 2 GeV and a target mass range of 16 to 209, excluding regions of strong nuclear deformation. They use a phenomenological approach guided by conclusions from recent microscopic studies. The experimental database consists largely of proton-nucleus elastic differential cross sections, analyzing powers, spin-rotation functions, and total reaction cross sections, and neutron-nucleus total cross sections. They will use this database in a nonlinear least-squares adjustment of optical model parameters in both relativistic equivalent Schroedinger (including relativistic kinematics) and Dirac (second-order reduction) formalisms. Isospin will be introduced through the standard Lane model and a relativistic generalization of that model.

  6. Full potential study of the elastic, electronic, and optical properties of spinels MgIn{sub 2}S{sub 4} and CdIn{sub 2}S{sub 4} under pressure effect

    SciTech Connect

    Semari, F. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali Liabes de Sidi Bel Abbes, Sidi Bel Abbes 22000 (Algeria); Khenata, R. [Laboratoire de Physique Quantique et de Modelisation Mathematique (LPQ3M), Departement de Technologie, Universite de Mascara, Mascara 29000 (Algeria); Depatment of Physics and Astronomy, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia); Rabah, M. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali Liabes de Sidi Bel Abbes, Sidi Bel Abbes 22000 (Algeria); Bouhemadou, A. [Depatment of Physics and Astronomy, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia); Laboratory for Developing New Materials and their Characterization, Faculty of Science, University of Setif, 19000 Setif (Algeria); Bin Omran, S. [Depatment of Physics and Astronomy, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia); Reshak, Ali H., E-mail: maalidph@yahoo.co.u [Institute of Physical Biology, South Bohemia University, Nove Hrady 373 33 (Czech Republic); School of Microelectronic Engineering, University Malaysia Perlis (UniMAP), Block A, Kompleks Pusat Pengajian, 02600 Arau Jejawi, Perlis (Malaysia); Rached, D. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali Liabes de Sidi Bel Abbes, Sidi Bel Abbes 22000 (Algeria)

    2010-12-15

    The structural, elastic, electronic, and optical properties of cubic spinel MgIn{sub 2}S{sub 4} and CdIn{sub 2}S{sub 4} compounds have been calculated using a full relativistic version of the full-potential linearized-augmented plane wave with the mixed basis FP/APW+lo method. The exchange and correlation potential is treated by the generalized-gradient approximation (GGA). Moreover, the Engel-Vosko GGA formalism is also applied to optimize the corresponding potential for band structure calculations. The ground state properties, including the lattice constants, the internal parameter, the bulk modulus, and the pressure derivative of the bulk modulus are in reasonable agreement with the available data. Using the total energy-strain technique, we have determined the full set of first-order elastic constants C{sub ij} and their pressure dependence, which have not been calculated or measured yet. The shear modulus, Young's modulus, and Poisson's ratio are calculated for polycrystalline XIn{sub 2}S{sub 4} aggregates. The Debye temperature is estimated from the average sound velocity. Electronic band structures show a direct band gap ({Gamma}-{Gamma}) for MgIn{sub 2}S{sub 4} and an indirect band gap (K-{Gamma}) for CdIn{sub 2}S{sub 4}. The calculated band gaps with EVGGA show a significant improvement over the GGA. The optical constants, including the dielectric function {epsilon}({omega}), the refractive index n({omega}), the reflectivity R({omega}), and the energy loss function L({omega}) were calculated for radiation up to 30 eV. -- Graphical abstract: Calculated total and partial densities of states for MgIn{sub 2}S{sub 4} and CdIn{sub 2}S{sub 4}

  7. Synergy of elastic and inelastic energy loss on ion track formation in SrTiO3

    PubMed Central

    Weber, William J.; Zarkadoula, Eva; Pakarinen, Olli H.; Sachan, Ritesh; Chisholm, Matthew F.; Liu, Peng; Xue, Haizhou; Jin, Ke; Zhang, Yanwen

    2015-01-01

    While the interaction of energetic ions with solids is well known to result in inelastic energy loss to electrons and elastic energy loss to atomic nuclei in the solid, the coupled effects of these energy losses on defect production, nanostructure evolution and phase transformations in ionic and covalently bonded materials are complex and not well understood due to dependencies on electron-electron scattering processes, electron-phonon coupling, localized electronic excitations, diffusivity of charged defects, and solid-state radiolysis. Here we show that a colossal synergy occurs between inelastic energy loss and pre-existing atomic defects created by elastic energy loss in single crystal strontium titanate (SrTiO3), resulting in the formation of nanometer-sized amorphous tracks, but only in the narrow region with pre-existing defects. These defects locally decrease the electronic and atomic thermal conductivities and increase electron-phonon coupling, which locally increase the intensity of the thermal spike for each ion. This work identifies a major gap in understanding on the role of defects in electronic energy dissipation and electron-phonon coupling; it also provides insights for creating novel interfaces and nanostructures to functionalize thin film structures, including tunable electronic, ionic, magnetic and optical properties. PMID:25578009

  8. The continuous energy dependence of pp differential elastic cross sections between 500 and 1200 MeV

    NASA Astrophysics Data System (ADS)

    Garçon, M.; Legrand, D.; Lombard, R. M.; Mayer, B.; Rouger, M.; Terrien, Y.; Nakach, A.

    1985-12-01

    Using an internal jet target in the Saturne synchrotron, we have measured the proton-proton differential elastic cross section at 90° c.m. as a continuous function of energy (from 500 to 1200 MeV) during the acceleration of the beam. The energy resolution is about 2 MeV. The results are compared to predictions of phase-shift analyses and discussed in connection with amplitude analyses at 90° c.m. No resonant structure was observed and no evidence for narrow dibaryons was found.

  9. A method for using neutron elastic scatter to create a variable energy neutron beam from a nearly monoenergetic neutron source

    NASA Astrophysics Data System (ADS)

    Whetstone, Z. D.; Kearfott, K. J.

    2015-07-01

    This work describes preliminary investigation into the design of a compact, portable, variable energy neutron source. The proposed method uses elastic neutron scatter at specific angles to reduce the energy of deuterium-deuterium or deuterium-tritium (D-T) neutrons. The research focuses on D-T Monte Carlo simulations, both in idealized and more realistic scenarios. Systematic uncertainty of the method is also analyzed. The research showed promise, but highlighted the need for discrimination of multiply-scattered neutrons, either through a pulsed generator or associated particle imaging.

  10. Polarizable interaction potential for water from coupled cluster calculations. I. Analysis of dimer potential energy surface

    E-print Network

    by nonadditive effects which make it impossible to sufficiently accurately represent the energy of water as a sumPolarizable interaction potential for water from coupled cluster calculations. I. Analysis of dimer potential energy surface Robert Bukowski,1 Krzysztof Szalewicz,1,a Gerrit C. Groenenboom,2 and Ad van der

  11. Cross sections for low-energy (1-100 eV) electron elastic and inelastic scattering in amorphous ice.

    PubMed

    Michaud, M; Wen, A; Sanche, L

    2003-01-01

    We report the integral cross sections per scatterer (i.e. elastic collision, phonon excitations, vibrational excitations, electronic excitations and ionization) for 1-100 eV electron scattering in an amorphous film of ice condensed at a temperature of 14 K. The integral cross sections are determined relative to the total from a two-stream multiple-scattering analysis of the electron energy distribution backscattered from the film. Their energy dependence is obtained from both the analysis of the elastic electron reflectivity as a function of the film thickness and the vibrational electron energy-loss spectra measured for several incident energies and large film thickness. The magnitude and various features found in the energy dependence of the cross sections are discussed, whenever possible, by comparison with data and with scattering mechanisms available in the gas phase. Microcospic effects, which are implicitly included in cross sections determined in this way, are discussed in terms of interference and coherent multiple-scattering contributions among the scattering sites as well as interactions of the scattering sites with their neighbors in the condensed phase. PMID:12492364

  12. Momentum potential theory of energy flux carried by momentum fluctuations

    Microsoft Academic Search

    P. E. Doak

    1989-01-01

    The momentum potential theory of time-stationary fluctuating flows is briefly reviewed and then extended to include energy flux carried by momentum fluctuations. It is shown that the mean (time-averaged) energy flux can be expressed as a linear superposition of mean, turbulent, acoustic and thermal components. A mean energy flux balance relating turbulent, acoustic and thermal energy fluxes only is obtained.

  13. Full potential calculation of structural, elastic and electronic properties of BaZrO3 and SrZrO3

    NASA Astrophysics Data System (ADS)

    Terki, R.; Feraoun, H.; Bertrand, G.; Aourag, H.

    2005-04-01

    Ab initio calculations have been performed on the structural and electronic properties of perovskite-type compounds BaZrO3 and SrZrO3 ceramics. The Kohn-Sham equations were solved by applying the full-potential linearized augmented-plane-wave (FP-LAPW) method. In this approach, the generalized gradient approximation was used for the exchange-correlation potential. The ground state properties such as lattice parameter, elastic constants, bulk modulus and its pressure derivative were calculated and the results are compared with previous calculations and experimental data when available. The SrZrO3 perovskite should exhibit higher hardness and stiffness than BaZrO3. Furthermore, the electronic structure calculations show that these materials are weakly ionic and exhibit indirect and wide band gaps, which are typical of insulators.

  14. Unique potentials for the elastic scattering of 350 MeV {sup 7}Li from {sup 12}C and {sup 28}Si

    SciTech Connect

    Nadasen, A.; Brusoe, J.; Farhat, J.; Stevens, T.; Williams, J.; Nieman, L. [University of Michigan, Dearborn, Michigan 48128 (United States)] [University of Michigan, Dearborn, Michigan 48128 (United States); Winfield, J.S. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)] [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Warner, R.E. [Oberlin College, Oberlin, Ohio 44075 (United States)] [Oberlin College, Oberlin, Ohio 44075 (United States); Becchetti, F.D.; Jaenecke, J.W.; Annakkage, T.; Bajema, J.; Roberts, D. [University of Michigan, Ann Arbor, Michigan 48109 (United States)] [University of Michigan, Ann Arbor, Michigan 48109 (United States); Govinden, H.S. [University of Durban-Westville, Durban (South Africa)] [University of Durban-Westville, Durban (South Africa)

    1995-10-01

    Differential cross sections for the elastic scattering of 350 MeV {sup 7}Li from {sup 12}C and {sup 28}Si have been measured. The characteristics of the angular distributions are very similar to those of 318 MeV {sup 6}Li scattering from the same targets, with diffractive oscillations at the forward angles and smooth exponential falloff, attributed to the dominance of far-side scattering, at the larger angles. The peak-to-valley ratios of the oscillatory structure are similar to those for {sup 6}Li, indicating that the {sup 7}Li ground-state quadrupole moment has no discernible effect on the cross sections. Like the {sup 6}Li data, the {sup 7}Li data define unique phenomenological optical-model potentials. Double-folding model potentials calculated from fundamental nucleon-nucleon interactions also provide reasonably good fits to the experimental data.

  15. Strong configurational dependence of elastic properties for a binary model metallic glass

    E-print Network

    Goddard III, William A.

    in a Cu­Zr binary metallic glass assessed by molecular dynamics simulations is reported. By directly evaluating the temperature dependence and configurational potential energy dependence of elastic constants-Rahman formalism22 to calculate elastic stiffness coefficients by con- stant temperature and constant volume nvt

  16. HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS

    SciTech Connect

    PARSA,Z.

    2000-04-07

    In this paper, high energy physics possibilities and future colliders are discussed. The {mu}{sup +} {mu}{sup {minus}} collider and experiments with high intensity muon beams as the stepping phase towards building Higher Energy Muon Colliders (HEMC) are briefly reviewed and encouraged.

  17. Energy efficiency of California buildings: technical potential and progress

    Microsoft Academic Search

    1983-01-01

    Estimates of the technical potential for improved energy efficiency in US buildings range up to 50% of current or projected consumption; this is comparable to estimated potential in French buildings. Several conservation varying estimates of savings, but generally less than 50%. Targets for achievable conservation in California, used in forecasting future energy demand and planning conservation programs, are even lower.

  18. Derivation of climate elasticity of runoff to assess the effects of climate change on annual runoff

    NASA Astrophysics Data System (ADS)

    Yang, Hanbo; Yang, Dawen

    2011-07-01

    Climate elasticity of runoff is an important indicator for evaluating the effects of climate change on runoff. Consequently, this paper proposes an analytical derivation of climate elasticity. Based on the mean annual water-energy balance equation, two dimensionless numbers (the elasticities of runoff to precipitation and potential evaporation) were derived. Combining the first-order differential of the Penman equation, the elasticities of runoff to precipitation, net radiation, air temperature, wind speed, and relative humidity were derived to separate the contributions of different climatic variables. The case study was carried out in the Futuo River catchment in the Hai River basin, as well as in 89 catchments of the Hai River and the Yellow River basins of China. Based on the mean annual of climatic variables, the climate elasticity in the Futuo River basin was estimated as follows: precipitation elasticity ?, net radiation elasticity ?, air temperature elasticity ?, wind speed elasticity ?, and relative humidity elasticity ?. In this catchment, precipitation decrease was mainly responsible for runoff decline, and wind speed decline had the second greatest effect on runoff. In the 89 catchments of the Hai River and the Yellow River basins of China, climate elasticity was estimated as follows: ? ranging from 1.6 to 3.9, ? ranging from -1.9 to -0.3, ? ranging from -0.11 to -0.02°C-1, ? ranging from -0.8 to -0.1, and ? ranging from 0.2 to 1.9. Additional analysis shows that climate elasticity was sensitive to catchment characteristics.

  19. Saturation wind power potential and its implications for wind energy

    E-print Network

    Saturation wind power potential and its implications for wind energy Mark Z. Jacobsona,1 to determine the maximum theo- retical wind power potential on Earth, based on the concept of "saturation". The saturation wind power potential (SWPP) is the maximum wind power that can be extracted upon increasing

  20. Rapid Hydrogel Microactuator Using Elastic Instability

    NASA Astrophysics Data System (ADS)

    Lee, Howon; Xia, Chunguang; Fang, Nicholas

    2009-03-01

    Rapid Hydrogel Microactuator Using Elastic Instability Inspired by rapid movement of sensitive plants such as Venus flytrap [1], we present an innovative way to enhance actuation speed of hydrogel micro devices by exploiting elastic instability. In this work, hydrogel micro devices in doubly curved shape are designed and fabricated using projection micro-stereolithography[2], with embedded microfluidic channels on the surface. Local swelling of hydrogel around channels causes bending which subsequently induces stretching of the soft structure. Such coupling gives rise to elastic instability, the onset of which triggers rapid conversion of stored elastic energy into kinetic energy in fast motion. We further designed a set of devices with different dimensions, which leads to different coupling of elastic energy in bending and stretching [1]. Our experimental results verified the critical coupling parameter that triggers snap-buckling motion. Ongoing experiments are investigating the actuation speed as a function of coupling parameter. This novel approach promises new potential applications for hydrogel based devices in various fields of study including microfluidics, soft robotics, artificial muscle, and drug delivery. Reference [1] Forterre, Y., et al, Nature, 433, 421-425 (2005) [2] Sun, C., et al, Sensors and Actuators A, 121:1, 113-120 (2005)

  1. Hydrogen - Potential key to tomorrow's energy utility

    Microsoft Academic Search

    R. M. Lundberg

    1978-01-01

    There are premium uses for fuels in the electric utility for which hydrogen seems appropriate. The cost of electrolytic conversion is marginal, but suitable for some utilities. The costs of storage may be the major obstacle to commercial scale development. There are adequate incentives and potentially a very large market to interest all utilities in the production of hydrogen for

  2. Potential energy savings on the MIT campus

    E-print Network

    Amanti, Steven Thomas

    2006-01-01

    The MIT community and the City of Cambridge embarked on initiatives to reduce energy consumption and Greenhouse Gas emissions in accordance with the Kyoto Protocol which calls for a 20 % reduction in 1990 levels of GHG ...

  3. Coulomb suppression in the low-energy p-p elastic scattering via the Trojan Horse Method

    SciTech Connect

    Tumino, A. [Laboratori Nazionali del Sud-INFN, via S. Sofia 62, 95123 Catania, Italy and Dipartimento di Metodologie Fisiche e Chimiche per l'Ingegneria, Universita di Catania (Italy); Universita degli Studi di Enna 'Kore', Enna (Italy); Spitaleri, C.; Rapisarda, G. G.; Cherubini, S.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Romano, S.; Sergi, M. L. [Laboratori Nazionali del Sud-INFN, via S. Sofia 62, 95123 Catania, Italy and Dipartimento di Metodologie Fisiche e Chimiche per l'Ingegneria, Universita di Catania (Italy); Mukhamedzhanov, A. [Cyclotron Institute, Texas A and M University, College Station (United States); Campajola, L. [Dipartimento di Scienze Fisiche-Universita Federico II, Napoli (Italy); Elekes, Z.; Fueloep, Zs.; Gyuerky, G.; Kiss, G. G.; Somorjai, E. [ATOMKI-Debrecen (Hungary); Gialanella, L. [INFN-Sezione di Napoli (Italy)

    2010-11-24

    We present here an important test of the main feature of the Trojan Horse Method (THM), namely the suppression of Coulomb effects in the entrance channel due to off-energy-shell effects. This is done by measuring the THM p-p elastic scattering via the p+d{yields}p+p+n reaction at 4.7 and 5 MeV, corresponding to a p-p relative energy ranging from 80 to 670 keV. In contrast to the on-energy-shell (OES) case, the extracted p-p cross section does not exhibit the Coulomb-nuclear interference minimum due to the suppression of the Coulomb amplitude. This is confirmed by the half-off-energy shell (HOES) calculations and strengthened by the agreement with the calculated OES nuclear cross sections.

  4. Energy potential of leafy spurge ( Euphorbia esula )

    Microsoft Academic Search

    B. D. Maxwell; S. M. Wiatr; P. K. Fay

    1985-01-01

    Leafy spurge (Euphorbia esula) is a noxious, perennial weed that infests pastures, rangeland and waste areas in the northern Great Plains. The objective\\u000a of this study was to determine the productive potential of this species when grown under optimum agronomic conditions. Plants\\u000a were fertilized and irrigated. Oil, hydrocarbon, total protein, and dry-weight production were measured on 3 harvest dates.\\u000a Calorimetric

  5. Synergistic effects from graphene and carbon nanotubes endow ordered hierarchical structure foams with a combination of compressibility, super-elasticity and stability and potential application as pressure sensors

    NASA Astrophysics Data System (ADS)

    Kuang, Jun; Dai, Zhaohe; Liu, Luqi; Yang, Zhou; Jin, Ming; Zhang, Zhong

    2015-05-01

    Nanostructured carbon material based three-dimensional porous architectures have been increasingly developed for various applications, e.g. sensors, elastomer conductors, and energy storage devices. Maintaining architectures with good mechanical performance, including elasticity, load-bearing capacity, fatigue resistance and mechanical stability, is prerequisite for realizing these functions. Though graphene and CNT offer opportunities as nanoscale building blocks, it still remains a great challenge to achieve good mechanical performance in their microarchitectures because of the need to precisely control the structure at different scales. Herein, we fabricate a hierarchical honeycomb-like structured hybrid foam based on both graphene and CNT. The resulting materials possess excellent properties of combined high specific strength, elasticity and mechanical stability, which cannot be achieved in neat CNT and graphene foams. The improved mechanical properties are attributed to the synergistic-effect-induced highly organized, multi-scaled hierarchical architectures. Moreover, with their excellent electrical conductivity, we demonstrated that the hybrid foams could be used as pressure sensors in the fields related to artificial skin.Nanostructured carbon material based three-dimensional porous architectures have been increasingly developed for various applications, e.g. sensors, elastomer conductors, and energy storage devices. Maintaining architectures with good mechanical performance, including elasticity, load-bearing capacity, fatigue resistance and mechanical stability, is prerequisite for realizing these functions. Though graphene and CNT offer opportunities as nanoscale building blocks, it still remains a great challenge to achieve good mechanical performance in their microarchitectures because of the need to precisely control the structure at different scales. Herein, we fabricate a hierarchical honeycomb-like structured hybrid foam based on both graphene and CNT. The resulting materials possess excellent properties of combined high specific strength, elasticity and mechanical stability, which cannot be achieved in neat CNT and graphene foams. The improved mechanical properties are attributed to the synergistic-effect-induced highly organized, multi-scaled hierarchical architectures. Moreover, with their excellent electrical conductivity, we demonstrated that the hybrid foams could be used as pressure sensors in the fields related to artificial skin. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00841g

  6. Measurement of Residual Elastic Strains in a Titanium Alloy Using High Energy Synchrotron X-Ray Diffraction

    Microsoft Academic Search

    A. M. Korsunsky; J. Liu; M. Golshan; D. Dini; S. Y. Zhang; W. J. Vorster

    2006-01-01

    Residual elastic strains in a bent bar of titanium alloy Ti-6Al-4V were measured using high energy diffraction on station\\u000a 16.3 at SRS Daresbury. Using a single bounce Laue crystal monochromator, diffraction peaks were collected for reflections\\u000a (00.2), (10.1), (10.2) and (11.0) from the hcp alpha phase of the titanium alloy. Reference values of the lattice spacing\\u000a for each of the

  7. Response to 'Comment on 'Elastic incoherent neutron scattering operating by varying instrumental energy resolution: Principle, simulations, and experiments of the resolution elastic neutron scattering (RENS)'' [Rev. Sci. Instrum. 83, 107101 (2012)

    SciTech Connect

    Magazu, Salvatore; Migliardo, Federica; Benedetto, Antonio [Dipartimento di Fisica, Universita di Messina, C.da Papardo n Degree-Sign 31, P.O. Box 55, Vill. S. Agata 98166 Messina (Italy)

    2012-10-15

    Recently [S. Magazu et al., Rev. Sci. Instrum. 82, 105115 (2011)] we have proposed a new method for characterizing, by neutron scattering, the dynamical properties of complex material systems, such as, the ones of interest in the biophysical field. This approach called Resolution Elastic Neutron Scattering, in short RENS, is based on the detection of the elastically scattered neutron intensity as a function of the instrumental energy resolution. By experimental, theoretical, and numerical findings, we have pointed out that an inflection point occurs in the elastic intensity when the system relaxation time approaches the instrumental energy resolution time. This approach, differently from quasi-elastic neutron scattering (QENS), gives the chance to evaluate the system relaxation times without using pre-defined models that can be wrong and/or misleading. Here, we reply to a Comment on the above-mentioned main paper in which Wuttke proposes a different approach to evaluate the above-mentioned inflection point; on this regard, it should be noticed that the existence of the inflection point, which is the main topic of our work, is not questioned and that the approach proposed by Wuttke in the Comment, although valid for a class of dynamical processes, is not applicable when different and distinct processes occur simultaneously at different time scale.

  8. Potential production of energy cane for fuel in the Caribbean

    SciTech Connect

    Samuels, G.

    1984-12-01

    Sugarcane presents a tremendous potential as a renewable energy source for the non-oil producing countries of the Caribbean. The energy cane concept is sugarcane managed for maximum dry matter (total fermentable solids for alcohol fuel and combustible solids for electricity) rather than sucrose. The use of sugarcane as a renewable energy source can provide a solution, either partial or total, to the Caribbean energy problem. Sugar cane production and the use of this crop as a renewable energy source are described.

  9. Elasticity theory of topological defects in carbon nanotubes and graphene

    Microsoft Academic Search

    E. Ertekin; M. S. Daw; D. C. Chrzan

    2008-01-01

    We develop elasticity theory to predict the energies of topological defects in carbon nanostructures. The theory is a simple, quantitatively accurate and transferable continuum approach to predicting defect formation energies that obviates the need for computationally expensive quantum mechanical methods. Thus the theory has the potential to serve as the basis for thermodynamic and multi-scale modelling of the structural properties

  10. Hydrogen energy - Its potential promises and problems

    Microsoft Academic Search

    G. D. Sauter

    1976-01-01

    The prospects for developing the use of hydrogen as a secondary fuel are discussed. Topics considered include: progress in improving thermochemical and electrolytic production of hydrogen, transportation of hydrogen in pipelines, differences in the combustion of hydrogen and natural gas, environmental and safety concerns (leaks through gas-tight fittings, low ignition energy), and the capital outlay required for widespread use of

  11. Comparing energy levels in isotropic and anisotropic potentials

    E-print Network

    Alexander Pikovski

    2015-06-28

    Qualitative information about the quantized energy levels of a system can be of great value. We study the relationship between the bound-state energies of an anisotropic potential and those of its spherical average. It is shown that the two ground-state energies satisfy an inequality, and there is a similar inequality for the first excited states.

  12. Periodic Discrete Energy for Long-Range Potentials

    E-print Network

    D. P. Hardin; E. B. Saff; Brian Simanek

    2014-12-11

    We consider periodic energy problems in Euclidean space with a special emphasis on long-range potentials that cannot be defined through the usual infinite sum. One of our main results builds on more recent developments of Ewald summation to define the periodic energy corresponding to a large class of long-range potentials. Two particularly interesting examples are the logarithmic potential and the Riesz potential when the Riesz parameter is smaller than the dimension of the space. For these examples, we use analytic continuation methods to provide concise formulas for the periodic kernel in terms of the Epstein Hurwitz Zeta function. We apply our energy definition to deduce several properties of the minimal energy including the asymptotic order of growth and the distribution of points in energy minimizing configurations as the number of points becomes large. We conclude with some detailed calculations in the case of one dimension, which shows the utility of this approach.

  13. Periodic discrete energy for long-range potentials

    NASA Astrophysics Data System (ADS)

    Hardin, D. P.; Saff, E. B.; Simanek, B.

    2014-12-01

    We consider periodic energy problems in Euclidean space with a special emphasis on long-range potentials that cannot be defined through the usual infinite sum. One of our main results builds on more recent developments of Ewald summation to define the periodic energy corresponding to a large class of long-range potentials. Two particularly interesting examples are the logarithmic potential and the Riesz potential when the Riesz parameter is smaller than the dimension of the space. For these examples, we use analytic continuation methods to provide concise formulas for the periodic kernel in terms of the Epstein Hurwitz Zeta function. We apply our energy definition to deduce several properties of the minimal energy including the asymptotic order of growth and the distribution of points in energy minimizing configurations as the number of points becomes large. We conclude with some detailed calculations in the case of one dimension, which shows the utility of this approach.

  14. Differences in intermediate-energy p-A and n-A elastic scattering observables

    NASA Astrophysics Data System (ADS)

    Karataglidis, S.; Madland, D. G.

    2001-04-01

    We compare differences in intermediate-energy proton-nucleus and neutron-nucleus scattering observables calculated from two formalisms. Specifically, we examine differential cross sections, analyzing powers, and spin rotations, calculated using Dirac phenomenology [1] and a Schrodinger approach based upon a realistic nucleon-nucleon potential [2]. We find a remarkable sensitivity to the presence or absence of the Coulomb field that yields essentially identical results for the two formalisms. Furthermore, we find an equally remarkable insensitivity, of both projectiles, to isospin. We discuss the systematics of our results. The equivalence of the results from the two disparate formalisms strongly suggests a number of new neutron scattering experiments. This work was supported by DOE Grant no. W-7405-ENG-36. [1] R. Kozack and D. G. Madland, Nucl. Phys. A509, 664 (1990). [2] K. Amos, P. J. Dortmans, H. V. von Geramb, S. Karataglidis, and J. Raynal, Adv. Nucl. Phys. 25, 276 (2000).

  15. Fission Potential Energy Surfaces in Ten-Dimensional Deformation Space

    NASA Astrophysics Data System (ADS)

    Pashkevich, V.; Pyatkov, Y.; Unzhakova, A.

    Various fission processes are described in terms of high-dimensional potential energy surface in the frame of the Strutinsky shell correction method for actinide region. The complete deformation space is necessary to study the potential energy minima responsible for the cluster radioactivity, cold fission and cold multi-fragmentation valleys. The nuclear shape families for the different fission configurations are obtained without any specific change of the parameters. The coordinate system based on the Cassini ovaloids makes it possible to increase the number of independent deformation parameters without divergence. The higher orders of the deformation are shown to play an important role in the description of the potential energy surface structure.

  16. Brittle fracture in a periodic structure with internal potential energy

    PubMed Central

    Mishuris, Gennady S.; Slepyan, Leonid I.

    2014-01-01

    We consider a brittle fracture taking account of self-equilibrated distributed stresses existing at microlevel in the absence of external forces. To determine how the latter can affect the crack equilibrium and growth, a model of a structured linearly elastic body is introduced, consisting of two equal symmetrically arranged layers (or half-planes) connected by an interface as a prospective crack path. The interface comprises a discrete set of elastic bonds. In the initial state, the bonds are assumed to be stressed in such a way that tensile and compressive forces of the same value alternate. In the general considerations, the layers are assumed to be of an unspecified periodic structure, where such self-equilibrated stresses may also exist. A two-line chain and a lattice are examined as the specified structure. We consider the states of the body-with-a-crack under such microlevel stresses (MS) and under a combined action of the remote forces and MS. Analytical solutions to the considered problems are presented based on the introduction of a selective discrete transform. We demonstrate that MS can increase as well as decrease the crack resistance depending on the internal energy level. We also discuss different scenarios of the crack growth. PMID:24808756

  17. Modification of nucleon-nucleon interactions in nuclear medium and neutron densities extracted via proton elastic scattering at intermediate energies

    NASA Astrophysics Data System (ADS)

    Takeda, Hiroyuki

    2003-03-01

    Spin rotation parameters of proton elastic scattering from 58Ni have been measured at Ep=200, 300 and 400 MeV. By combining them with the previously measured cross sections and analyzing powers at the same energies, the series of measurements has become the "complete" experiment. Cross sections and analyzing powers of proton elastic scattering from 58Ni at 250 MeV, those of 120Sn at Ep=200, 250, 300 and 400 MeV and spin rotation parameters of 120Sn at Ep=300 MeV have been also newly measured. The experiment has been performed at Research Center for Nuclear Phyiscs, Osaka University. In order to explain the 58Ni data, it has been necessary to use realistic density distributions deduced from the nuclear charge distribution and to modify coupling constants and masses of ? and ? mesons. For 120Sn, we have assumed the same modification and used the proton distribution deduced from the charge distribution, we have searched the neutron density distribution which has reproduced 120Sn data at 300 MeV. The deduced neutron distribution has an increase at the nuclear center, which seems to be due to wave functions of neutrons in the 3s1/2 orbit. It also explains the 120Sn data at other energies than 300 MeV. Effects of ? meson modifications on neutron densities are also mentioned.

  18. Polarizable interaction potential for water from coupled cluster calculations. I. Analysis of dimer potential energy surface

    NASA Astrophysics Data System (ADS)

    Bukowski, Robert; Szalewicz, Krzysztof; Groenenboom, Gerrit C.; van der Avoird, Ad

    2008-03-01

    A six-dimensional interaction potential for the water dimer has been fitted to ab initio interaction energies computed at 2510 dimer configurations. These energies were obtained by combining the supermolecular second-order energies extrapolated to the complete basis set limit from up to quadruple-zeta quality basis sets with the contribution from the coupled-cluster method including single, double, and noniterative triple excitations computed in a triple-zeta quality basis set. All basis sets were augmented by diffuse functions and supplemented by midbond functions. The energies have been fitted using an analytic form with the induction component represented by a polarizable term, making the potential directly transferable to clusters and the bulk phase. Geometries and energies of stationary points on the potential surface agree well with the results of high-level ab initio geometry optimizations.

  19. Polarizable interaction potential for water from coupled cluster calculations. I. Analysis of dimer potential energy surface.

    PubMed

    Bukowski, Robert; Szalewicz, Krzysztof; Groenenboom, Gerrit C; van der Avoird, Ad

    2008-03-01

    A six-dimensional interaction potential for the water dimer has been fitted to ab initio interaction energies computed at 2510 dimer configurations. These energies were obtained by combining the supermolecular second-order energies extrapolated to the complete basis set limit from up to quadruple-zeta quality basis sets with the contribution from the coupled-cluster method including single, double, and noniterative triple excitations computed in a triple-zeta quality basis set. All basis sets were augmented by diffuse functions and supplemented by midbond functions. The energies have been fitted using an analytic form with the induction component represented by a polarizable term, making the potential directly transferable to clusters and the bulk phase. Geometries and energies of stationary points on the potential surface agree well with the results of high-level ab initio geometry optimizations. PMID:18331099

  20. Converted Phase Elastic Migration Velocity Analysis

    E-print Network

    Shabelansky, Andrey Hanan

    2013-01-01

    Multi-component elastic seismic data collected at large offsets have the potential to be used in seismic imaging and velocity analysis. In this study, we present an approach for converted-phase elastic-transmission migration ...

  1. New approach to calculating the potential energy of colliding nuclei

    NASA Astrophysics Data System (ADS)

    Kurmanov, R. S.; Kosenko, G. I.

    2014-12-01

    The differential method proposed by the present authors earlier for the reduction of volume integrals in calculating the potential energy of a compound nucleus is generalized to the case of two interacting nuclei. The Coulomb interaction energy is obtained for the cases of a sharp and a diffuse boundary of nuclei, while the nuclear interaction energy is found only for nuclei with a sharp boundary, the finiteness of the nuclear-force range being taken into account. The present method of calculations permits reducing the time it takes to compute the potential energy at least by two orders of magnitude.

  2. New approach to calculating the potential energy of colliding nuclei

    SciTech Connect

    Kurmanov, R. S., E-mail: kurmanovrs@mail.ru [Omsk State Transport University (Russian Federation); Kosenko, G. I., E-mail: kosenkophys@gmail.com [Omsk Tank Engineering Institute (Russian Federation)

    2014-12-15

    The differential method proposed by the present authors earlier for the reduction of volume integrals in calculating the potential energy of a compound nucleus is generalized to the case of two interacting nuclei. The Coulomb interaction energy is obtained for the cases of a sharp and a diffuse boundary of nuclei, while the nuclear interaction energy is found only for nuclei with a sharp boundary, the finiteness of the nuclear-force range being taken into account. The present method of calculations permits reducing the time it takes to compute the potential energy at least by two orders of magnitude.

  3. Energy Savings Potential of Process Control Valve Replacement 

    E-print Network

    Holzenthal, L. Jr.

    1994-01-01

    address other possible solutions for partial energy cost recovery. Since the theoretic potential savings is not always the practical case, a set of guidelines for the application ofthis data is proposed that would allow the user to more easily locate...

  4. Energy Savings Potential of Process Control Valve Replacement

    E-print Network

    Holzenthal, L. Jr.

    A review of current design methods for industrial process control systems that utilize modulated control valves as their final element is presented. The infornUltion that is available is then used to find the theoretic potential for energy savings...

  5. Extraction of Neutron Density Distributions from Proton Elastic Scattering at Intermediate Energies

    NASA Astrophysics Data System (ADS)

    Takeda, H.; Sakaguchi, H.; Terashima, S.; Taki, T.; Yosoi, M.; Itoh, M.; Kawabata, T.; Ishikawa, T.; Uchida, M.; Tsukahara, N.; Yasuda, Y.; Noro, T.; Yoshimura, M.; Fujimura, H.; Yoshida, H. P.; Obayashi, E.; Tamii, A.; Akimune, H.

    2003-04-01

    Cross sections, analyzing powers and spin rotation parameters of proton elastic scattering from 58Ni and 120Sn have been measured at 200-400 MeV. Obtained data have been analyzed in the framework of relativistic impulse approximations. In order to explain the 58Ni data, it was necessary to modify NN interactions in the nuclear medium by changing coupling constants and masses of ? and ? mesons. For 120Sn, by assuming the same modification of NN interactions and by using proton densities deduced from charge densities, the neutron density distribution was searched so as to reproduce 120Sn data at 300 MeV.

  6. Fusion at deep subbarrier energies: potential inversion revisited

    E-print Network

    K. Hagino; N. Rowley

    2008-11-15

    For a single potential barrier, the barrier penetrability can be inverted based on the WKB approximation to yield the barrier thickness. We apply this method to heavy-ion fusion reactions at energies well below the Coulomb barrier and directly determine the inter-nucleus potential between the colliding nuclei. To this end, we assume that fusion cross sections at deep subbarrier energies are governed by the lowest barrier in the barrier distribution. The inverted inter-nucleus potentials for the $^{16}$O +$^{144}$Sm and $^{16}$O +$^{208}$Pb reactions show that they are much thicker than phenomenological potentials. We discuss a consequence of such thick potential by fitting the inverted potentials with the Bass function.

  7. Fusion at deep subbarrier energies: potential inversion revisited

    SciTech Connect

    Hagino, K. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Rowley, N. [Institut Pluridisciplinaire Hubert Curien (UMR 7178: CNRS/ULP), 23 rue du Loess, F-67037 Strasbourg Cedex 2 (France)

    2009-03-04

    For a single potential barrier, the barrier penetrability can be inverted based on the WKB approximation to yield the barrier thickness. We apply this method to heavy-ion fusion reactions at energies well below the Coulomb barrier and directly determine the inter-nucleus potential between the colliding nuclei. To this end, we assume that fusion cross sections at deep subbarrier energies are governed by the lowest barrier in the barrier distribution. The inverted inter-nucleus potentials for the {sup 16}O+{sup 144}Sm and {sup 16}O+{sup 208}Pb reactions show that they are much thicker than phenomenological potentials. We discuss a consequence of such thick potential by fitting the inverted potentials with the Bass function.

  8. Energy savings potential from energy-conserving irrigation systems

    SciTech Connect

    Wilfert, G.L.; Patton, W.P.; Harrer, B.J.; Clark, M.A.

    1982-11-01

    This report systematically compares, within a consistent framework, the technical and economic characteristics of energy-conserving irrigation systems with those of conventional irrigation systems and to determine total energy savings. Levelized annual costs of owning and operating both energy-conserving and conventional irrigation systems have been developed and compared for all 17 states to account for the differences in energy costs and irrigation conditions in each state. Market penetration of energy-conserving systems is assessed for those systems having lower levelized annual costs than conventional systems performing the same function. Annual energy savings were computed by matching the energy savings per system with an assumed maximum market penetration of 100 percent in those markets where the levelized annual costs of energy-conserving systems are lower than the levelized annual costs of conventional systems.

  9. Nuclear momentum distribution and potential energy surface in hexagonal ice

    Microsoft Academic Search

    Lin Lin; Joseph Morrone; Roberto Car; Michele Parrinello

    2011-01-01

    The proton momentum distribution in ice Ih has been recently measured by deep inelastic neutron scattering and calculated from open path integral Car-Parrinello simulation. Here we report a detailed investigation of the relation between momentum distribution and potential energy surface based on both experiment and simulation results. The potential experienced by the proton is largely harmonic and characterized by 3

  10. Elastic Energy and Phase Structure in a Continuous Spin Ising Chain with Applications to the Protein Folding Problem

    E-print Network

    M. N. Chernodub; Martin Lundgren; Antti J. Niemi

    2010-08-26

    We present a numerical Monte Carlo analysis of a continuos spin Ising chain that can describe the statistical proterties of folded proteins. We find that depending on the value of the Metropolis temperature, the model displays the three known nontrivial phases of polymers: At low temperatures the model is in a collapsed phase, at medium temperatures it is in a random walk phase, and at high temperatures it enters the self-avoiding random walk phase. By investigating the temperature dependence of the specific energy we confirm that the transition between the collapsed phase and the random walk phase is a phase transition, while the random walk phase and self-avoiding random walk phase are separated from each other by a cross-over transition. We also compare the predictions of the model to a phenomenological elastic energy formula, proposed by Huang and Lei to describe folded proteins.

  11. Elastic scattering of low-energy electrons by CF3Cl, CF3Br and CF3I

    NASA Astrophysics Data System (ADS)

    Bettega, M. H. F.; Natalense, A. P. P.; Lima, M. A. P.; Ferreira, L. G.

    2003-03-01

    We report integral, differential and momentum transfer cross sections for elastic scattering of low-energy electrons by CF3X (X = Cl, Br, I) molecules. We use the Schwinger multichannel method with pseudopotentials (Bettega et al1993 Phys. Rev. A 47 1111) at the static exchange approximation. Our calculations cover the energy range between 5 and 30 eV. We compare our results with available theoretical and experimental results for CF3Cl and CF3I, and in general find good agreement. In particular, our results show the shape resonances belonging to the A1 and E representations of the C3v group that have been reported by previous work.

  12. Elasto-capillarity at the nanoscale: on the coupling between elasticity and surface energy in soft solids

    E-print Network

    Joost H. Weijs; Bruno Andreotti; Jacco H. Snoeijer

    2013-05-30

    The capillary forces exerted by liquid drops and bubbles on a soft solid are directly measured using molecular dynamics simulations. The force on the solid by the liquid near the contact line is not oriented along the liquid vapor interface nor perpendicular to the solid surface, as usually assumed, but points towards the liquid. It is shown that the elastic deformations induced by this force can only be explained if, contrary to an incompressible liquid, the surface stress is different from the surface energy. Using thermodynamic variations we show that the the surface stress and the surface energy can both be determined accurately by measuring the deformation of a slender body plunged in a liquid. The results obtained from molecular dynamics fully confirm those recently obtained experimentally [Marchand et al. Phys. Rev. Lett. 108, 094301 (2012)] for an elastomeric wire.

  13. Kappa distribution in the presence of a potential energy

    NASA Astrophysics Data System (ADS)

    Livadiotis, George

    2015-02-01

    The present paper develops the theory and formulations of the kappa distributions that describe particle systems characterized by a nonzero potential energy. As yet, kappa distributions were used for the statistical description of the velocity or kinetic energy of particles but not of the potential energy. With the results provided here, it is straightforward to use the developed kappa distributions to describe any particle population of space plasmas subject to a nonnegligible potential energy. Starting from the kappa distribution of the Hamiltonian function, we develop the distributions that describe either the complete phase space or the marginal spaces of positions and velocities. The study shows, among others: (a) The kappa distributions of velocities that describe space plasmas can be vastly different from the standard formulation of the kappa distribution, because of the presence of a potential energy; the correct formulation should be given by the marginal kappa distribution of velocities by integrating the distribution of the Hamiltonian over the potential energy. (b) The long-standing problem of the divergence of the Boltzmannian exponential distribution for bounded radial potentials is solved using kappa distributions of negative kappa index. (c) Anisotropic distributions of velocities can exist in the presence of a velocity-dependent potential. (d) A variety of applications, including derivations/verifications of the following: (i) the Jeans', the most frequent, and the maximum radii in spherical/linear gravitational potentials; (ii) the Virial theorem for power law potentials; (iii) the generalized barometric formula, (iv) the plasma density profiles in Saturnian magnetosphere, and (v) the average electron magnetic moment in Earth's magnetotail.

  14. THE JOURNAL OF CHEMICAL PHYSICS 134, 065105 (2011) Calculation of the Helmholtz potential of an elastic strand in an

    E-print Network

    Schieber, Jay D.

    2011-01-01

    attention for the past decade,5 because it was shown that genome sequence de- termines protein structure that entanglements of the molecule with the polymer network dominate chain dynamics. These entan- glements includes finite chain extensibility effects. The Helmholtz potential may be used in modeling the dynamics

  15. Investigating energy-saving potentials in the cloud.

    PubMed

    Lee, Da-Sheng

    2014-01-01

    Collecting webpage messages can serve as a sensor for investigating the energy-saving potential of buildings. Focusing on stores, a cloud sensor system is developed to collect data and determine their energy-saving potential. The owner of a store under investigation must register online, report the store address, area, and the customer ID number on the electric meter. The cloud sensor system automatically surveys the energy usage records by connecting to the power company website and calculating the energy use index (EUI) of the store. Other data includes the chain store check, company capital, location price, and the influence of weather conditions on the store; even the exposure frequency of store under investigation may impact the energy usage collected online. After collecting data from numerous stores, a multi-dimensional data array is constructed to determine energy-saving potential by identifying stores with similarity conditions. Similarity conditions refer to analyzed results that indicate that two stores have similar capital, business scale, weather conditions, and exposure frequency on web. Calculating the EUI difference or pure technical efficiency of stores, the energy-saving potential is determined. In this study, a real case study is performed. An 8-dimensional (8D) data array is constructed by surveying web data related to 67 stores. Then, this study investigated the savings potential of the 33 stores, using a site visit, and employed the cloud sensor system to determine the saving potential. The case study results show good agreement between the data obtained by the site visit and the cloud investigation, with errors within 4.17%. Among 33 the samples, eight stores have low saving potentials of less than 5%. The developed sensor on the cloud successfully identifies them as having low saving potential and avoids wasting money on the site visit. PMID:24561405

  16. Exact Description of Rotational Waves in an Elastic Solid

    E-print Network

    R. A. Close

    2010-12-03

    Conventional descriptions of transverse waves in an elastic solid are limited by an assumption of infinitesimally small gradients of rotation. By assuming a linear response to variations in orientation, we derive an exact description of a restricted class of rotational waves in an ideal isotropic elastic solid. The result is a nonlinear equation expressed in terms of Dirac bispinors. This result provides a simple classical interpretation of relativistic quantum mechanical dynamics. We construct a Lagrangian of the form L=-E+U+K=0, where E is the total energy, U is the potential energy, and K is the kinetic energy.

  17. Framework for State-Level Renewable Energy Market Potential Studies

    SciTech Connect

    Kreycik, C.; Vimmerstedt, L.; Doris, E.

    2010-01-01

    State-level policymakers are relying on estimates of the market potential for renewable energy resources as they set goals and develop policies to accelerate the development of these resources. Therefore, accuracy of such estimates should be understood and possibly improved to appropriately support these decisions. This document provides a framework and next steps for state officials who require estimates of renewable energy market potential. The report gives insight into how to conduct a market potential study, including what supporting data are needed and what types of assumptions need to be made. The report distinguishes between goal-oriented studies and other types of studies, and explains the benefits of each.

  18. Communication: Separable potential energy surfaces from multiplicative artificial neural networks

    NASA Astrophysics Data System (ADS)

    Koch, Werner; Zhang, Dong H.

    2014-07-01

    We present a potential energy surface fitting scheme based on multiplicative artificial neural networks. It has the sum of products form required for efficient computation of the dynamics of multidimensional quantum systems with the multi configuration time dependent Hartree method. Moreover, it results in analytic potential energy matrix elements when combined with quantum dynamics methods using Gaussian basis functions, eliminating the need for a local harmonic approximation. Scaling behavior with respect to the complexity of the potential as well as the requested accuracy is discussed.

  19. Communication: separable potential energy surfaces from multiplicative artificial neural networks.

    PubMed

    Koch, Werner; Zhang, Dong H

    2014-07-14

    We present a potential energy surface fitting scheme based on multiplicative artificial neural networks. It has the sum of products form required for efficient computation of the dynamics of multidimensional quantum systems with the multi configuration time dependent Hartree method. Moreover, it results in analytic potential energy matrix elements when combined with quantum dynamics methods using Gaussian basis functions, eliminating the need for a local harmonic approximation. Scaling behavior with respect to the complexity of the potential as well as the requested accuracy is discussed. PMID:25027992

  20. Communication: Separable potential energy surfaces from multiplicative artificial neural networks

    SciTech Connect

    Koch, Werner, E-mail: wkoch@thethirdrock.net; Zhang, Dong H. [State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian (China)

    2014-07-14

    We present a potential energy surface fitting scheme based on multiplicative artificial neural networks. It has the sum of products form required for efficient computation of the dynamics of multidimensional quantum systems with the multi configuration time dependent Hartree method. Moreover, it results in analytic potential energy matrix elements when combined with quantum dynamics methods using Gaussian basis functions, eliminating the need for a local harmonic approximation. Scaling behavior with respect to the complexity of the potential as well as the requested accuracy is discussed.

  1. Numerical investigation of the turbulent energy budget in the wake of freely oscillating elastically mounted cylinder at low reduced velocities

    NASA Astrophysics Data System (ADS)

    Sarkar, Abhishek; Schlüter, Jörg

    2013-11-01

    We present a numerical study of the turbulent kinetic energy budget in the wake of cylinders undergoing Vortex-Induced Vibration (VIV). We show three-dimensional Large Eddy Simulations (LES) of an elastically mounted circular cylinder in the synchronization regime at Reynolds number of Re=8000. The Immersed Boundary Method (IBM) is used to account for the presence of the cylinder. The flow field in the wake is decomposed using the triple decomposition splitting the flow variables in mean, coherent and stochastic components. The energy transfer between these scales of motions are then studied and the results of the free oscillation are compared to those of a forced oscillation. The turbulent kinetic energy budget shows that the maximum amplitude of VIV is defined by the ability of the mean flow to feed energy to the coherent structures in the wake. At amplitudes above this maximum amplitude, the energy of the coherent structures needs to be fed additionally by small scale, stochastic energy in form of backscatter to sustain its motion. Furthermore, we demonstrate that the maximum amplitude of the VIV is defined by the integral length scale of the turbulence in the wake.

  2. Using peat for energy: Potential environmental restraints. Overview

    Microsoft Academic Search

    R. M. Reed; L. D. Voorhees; P. J. Mulholland

    1981-01-01

    Serious consideration is being given to using peat as an energy resource in Minnesota, North Carolina, Florida, and some New England States. Potential environmental constraints for using peat as an energy resource are associated with disruption of important regional wetland ecosystems. Mining peatlands may significantly modify ground and surface water hydrology, degrade water quality in downstream receiving systems, contribute to

  3. Overview - using peat for energy: potential environmental constraints

    Microsoft Academic Search

    R. M. Reed; L. D. Voorhees; P. J. Mulholland

    1981-01-01

    Serious consideration is being given to using peat as an energy resource in Minnesota, North Carolina, Florida, and some New England States. Potential environmental constraints for using peat as an energy resource are associated with disruption of important regional wetland ecosystems. Mining peatlands may significantly modify ground and surface water hydrology, degrade water quality in downstream receiving systems, contribute to

  4. Potential for energy conservation: St. Louis Case Study

    Microsoft Academic Search

    M. D. Levine; J. P. Whittier

    1979-01-01

    The method of approach to study energy conservation potential in St. Louis is described. It is observed that the key features of St. Louis are: uncertainty of population and economic projections; growth of suburban areas and decline of the inner city during the past two decades; inner city has numerous social\\/economic problems; inadequate (economically suboptimal) levels of energy conservation in

  5. An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel

    E-print Network

    Stanford University

    been used to convert wind flow energy into mechanical vibration, which is then transformed for an energy harvester to extract energy. To overcome this limitation, we use wind-induced flutter vibration BACKGOURND 2.1. Wind as a source for energy harvesting Wind energy has long been used to generate power

  6. Potential production of energy cane for fuel in the Caribbean

    SciTech Connect

    Samuels, G.

    1984-08-01

    Sugarcane grown as energy cane presents a new potential to the Caribbean countries to provide their own energy needs and to reduce or eliminate fuel oil imports. The use of proper agronomic techniques can convert conventional sugarcane growing to a crop capable of giving energy feedstocks in the form of fiber for boiler fuel for electricity and fermentable solids for alcohol for motor fuel. Sugarcane can still be obtained from the energy cane for domestic consumption and export if desired. The aerable land now devoted to sugarcane can utilized for energy-cane production without causing any serious imbalance in food crop production.

  7. Renewable energy potential in Bulgaria - Some computer simulations results

    NASA Astrophysics Data System (ADS)

    Ganev, K.; Jordanov, G.; Gadzhev, G.; Miloshev, N.; Syrakov, D.; Prodanova, M.

    2014-11-01

    The paper presents a work, which aims at numerical study of the wind and solar energy potential of the country. The wind/solar energy fields simulations were performed applying the 5th generation PSU/NCAR Meso-Meteorological Model MM5 for years 2000-2007 with a spatial resolution of 3 km over Bulgaria. The computer simulated data base is large and rather comprehensive. In this sense it can be considered as statistically significant ensemble. This allows statistical treatment in order various wind and solar energy potential evaluations to be retrieved from the data base. Some evaluations of the country wind and solar energy potential, based on the simulation output are demonstrated in the paper.

  8. On the nuclear interaction. Potential, binding energy and fusion reaction

    E-print Network

    I. Casinos

    2008-05-22

    The nuclear interaction is responsible for keeping neutrons and protons joined in an atomic nucleus. Phenomenological nuclear potentials, fitted to experimental data, allow one to know about the nuclear behaviour with more or less success where quantum mechanics is hard to be used. A nuclear potential is suggested and an expression for the potential energy of two nuclear entities, either nuclei or nucleons, is developed. In order to estimate parameters in this expression, some nucleon additions to nuclei are considered and a model is suggested as a guide of the addition process. Coulomb barrier and energy for the addition of a proton to each one of several nuclei are estimated by taking into account both the nuclear and electrostatic components of energy. Studies on the binding energies of several nuclei and on the fusion reaction of two nuclei are carried out.

  9. Role of elastic energy in the formation of ferroelectric barium strontium titanate films on sapphire

    NASA Astrophysics Data System (ADS)

    Tumarkin, A. V.; Kukushkin, S. A.; Osipov, A. V.; Ankudinov, A. S.; Odinets, A. A.

    2015-04-01

    The initial stages of the growth of ferroelectric barium strontium titanate (BaSrTiO3) films on single-crystal sapphire substrates have been investigated experimentally. It has been shown that the vapor-solid phase transition at the initial stage of the deposition of the BaSrTiO3 film on sapphire occurs in two stages. At the first stage, an elastically strained wetting layer that inheres the structure of the substrate is formed on the surface. At the same time, a strong electric charge is formed on the surface of the wetting layer. At the second stage of the phase transition, the wetting layer loses stability and transforms into BaSrTiO3 nuclei, which further merge to form a solid film.

  10. Target dependences in intermediate energy proton- and neutron-nucleus elastic scattering

    NASA Astrophysics Data System (ADS)

    Karataglidis, S.; Madland, D. G.

    2001-10-01

    Major differences in the spin observables in proton-nucleus and neutron-nucleus elastic scattering at 100 MeV were first observed by Kozack and Madland [1] in the case of scattering from ^208Pb, using a relativistic Dirac phenomenological optical model. The observation was confirmed using a microscopic Schrodinger optical model [2]. The difference has been attributed primarily to the presence (or absence) of the Coulomb interaction. We extend this investigation of the probe sensitivity, using the microscopic model, to include the additional dependence upon target mass and isospin. Results for the differential cross sections, analyzing powers, and spin rotations will be presented for 100 MeV scattering by ^12C, ^90Zr, ^96Zr, and ^208Pb. [1] R. Kozack and D. G. Madland, Nucl. Phys. A509, 664 (1990). [2] S. Karataglidis and D. G. Madland, nucl-th/0103048, submitted to Phys. Rev. Lett.

  11. Quasi-elastic scattering in the Li6+Th232 reaction

    NASA Astrophysics Data System (ADS)

    Mukherjee, S.; Nayak, B. K.; Monteiro, D. S.; Lubian, J.; Gomes, P. R. S.; Appannababu, S.; Choudhury, R. K.

    2009-07-01

    Quasi-elastic scattering measurements at large backward angles have been carried out for the Li6+Th232 system at energies around the Coulomb barrier. Barrier distribution has been obtained from the excitation function data. Coupled channel calculations using a double-folding potential as the bare potential have been performed. The disagreement between data and theoretical predictions shows a large breakup effect in the quasi-elastic scattering of a weakly bound projectile on a deformed target.

  12. The stability of a cylindrical elastic membrane of biological tissue and the effect of internal fluid flow

    Microsoft Academic Search

    J. S. K. Wong; R. T. Shield

    1980-01-01

    Some stability problems for finitely deformed elastic membranes are considered. The first part treats the stability of a stretched elastic membrane which is orthotropic in its reference state. The stability criteria for a uniformly deformed orthotropic plane sheet under conditions of dead loading are obtained. The potential energy for a uniformly extended and inflated circular cylindrical membrane (the preferred directions

  13. Optimizing potential energy functions for maximal intrinsic hyperpolarizability

    SciTech Connect

    Zhou Juefei; Szafruga, Urszula B.; Kuzyk, Mark G. [Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States); Watkins, David S. [Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States); Department of Mathematics, Washington State University, Pullman, Washington 99164-3113 (United States)

    2007-11-15

    We use numerical optimization to study the properties of (1) the class of one-dimensional potential energy functions and (2) systems of point nuclei in two dimensions that yield the largest intrinsic hyperpolarizabilities, which we find to be within 30% of the fundamental limit. In all cases, we use a one-electron model. It is found that a broad range of optimized potentials, each of very different character, yield the same intrinsic hyperpolarizability ceiling of 0.709. Furthermore, all optimized potential energy functions share common features such as (1) the value of the normalized transition dipole moment to the dominant state, which forces the hyperpolarizability to be dominated by only two excited states and (2) the energy ratio between the two dominant states. All optimized potentials are found to obey the three-level ansatz to within about 1%. Many of these potential energy functions may be implementable in multiple quantum well structures. The subset of potentials with undulations reaffirm that modulation of conjugation may be an approach for making better organic molecules, though there appear to be many others. Additionally, our results suggest that one-dimensional molecules may have larger diagonal intrinsic hyperpolarizability {beta}{sub xxx}{sup int} than higher-dimensional systems.

  14. First Results of a Detailed Analysis of p+p Elastic Scattering Data from ISR to LHC Energies in the Quark-Diquark Model

    E-print Network

    F. Nemes; T. Csörg?

    2012-02-11

    First results of a detailed analysis of p+p elastic scattering data are presented from ISR to LHC energies utilizing the quark-diquark model of protons in a form proposed by Bialas and Bzdak. The differential cross-section of elastic proton-proton collisions is analyzed in detailed and systematic manner at small momentum transfers, starting from the energy range of CERN ISR at $\\sqrt{s}= 23.5$ GeV, including also recent TOTEM data at the present LHC energies at $\\sqrt{s} = 7$ TeV. These studies confirm the picture that the size of protons increases systematically with increasing energies, while the size of the constituent quarks and diquarks remains approximately independent of (or only increases only slightly with) the colliding energy. The detailed analysis indicates correlations between model parameters and also indicates an increasing role of shadowing at LHC energies.

  15. The metabolic energy cost of action potential velocity

    NASA Astrophysics Data System (ADS)

    Crotty, Patrick; Sangrey, Thomas; Levy, William

    2006-03-01

    Voltage changes in neurons and other active cells are caused by the passage of ions across the cell membrane. These ionic currents depend on the transmembrane ion concentration gradients, which in unmyelinated axons are maintained during rest and restored after electrical activity by an ATPase sodium-potassium exchanger in the membrane. The amount of ATP consumed by this exchanger can be taken as the metabolic energy cost of any electrical activity in the axon. We use this measure, along with biophysical models of voltage-gated sodium and potassium ion channels, to quantify the energy cost of action potentials propagating in squid giant axons. We find that the energy of an action potential can be naturally divided into three separate components associated with different aspects of the action potential. We calculate these energy components as functions of the ion channel densities and axon diameters and find that the component associated with the rising phase and velocity of the action potential achieves a minimum near the biological values of these parameters. This result, which is robust with respect to other parameters such as temperature, suggests that evolution has optimized the axon for the energy of the action potential wavefront.

  16. Split kinetic energy method for quantum systems with competing potentials

    SciTech Connect

    Mineo, H.; Chao, Sheng D., E-mail: sdchao@spring.iam.ntu.edu.tw

    2012-09-15

    For quantum systems with competing potentials, the conventional perturbation theory often yields an asymptotic series and the subsequent numerical outcome becomes uncertain. To tackle such a kind of problems, we develop a general solution scheme based on a new energy dissection idea. Instead of dividing the potential energy into 'unperturbed' and 'perturbed' terms, a partition of the kinetic energy is performed. By distributing the kinetic energy term in part into each individual potential, the Hamiltonian can be expressed as the sum of the subsystem Hamiltonians with respective competing potentials. The total wavefunction is expanded by using a linear combination of the basis sets of respective subsystem Hamiltonians. We first illustrate the solution procedure using a simple system consisting of a particle under the action of double {delta}-function potentials. Next, this method is applied to the prototype systems of a charged harmonic oscillator in strong magnetic field and the hydrogen molecule ion. Compared with the usual perturbation approach, this new scheme converges much faster to the exact solutions for both eigenvalues and eigenfunctions. When properly extended, this new solution scheme can be very useful for dealing with strongly coupling quantum systems. - Highlights: Black-Right-Pointing-Pointer A new basis set expansion method is proposed. Black-Right-Pointing-Pointer Split kinetic energy method is proposed to solve quantum eigenvalue problems. Black-Right-Pointing-Pointer Significant improvement has been obtained in converging to exact results. Black-Right-Pointing-Pointer Extension of such methods is promising and discussed.

  17. Light element analysis in steel by high energy heavy ion time of flight elastic recoil detection analysis

    NASA Astrophysics Data System (ADS)

    Hong, Wan; Hayakawa, Shinjiro; Maeda, Kuniko; Fukuda, Shigekazu; Gohshi, Yohichi

    1999-01-01

    Time of flight elastic recoil detection analysis (TOF-ERDA) using high-energy heavy ions has been applied to determining the composition of light elements in stainless-steel (SUS304) samples before and after welding in order to monitor the variation in the composition of light elements in sample surfaces during a welding process. An argon-welding method using a welding rod (SUS304) and an arc-welding method using a welding rod were used to prepare samples. Four samples, welded and non-welded using two welding methods, were measured. 40Ar ions accelerated to 40.3 MeV were used as a probe. Carbon, oxygen and sodium were measured. It was found that the oxygen distributions near to the surfaces of the welded samples increased compared with those of the non-welded samples. However, variations in the carbon distributions were relatively smaller than that of oxygen distributions.

  18. Magnetic inhomogeneity on a triangular lattice: the magnetic-exchange versus the elastic energy and the role of disorder.

    PubMed

    Zorko, A; Kokalj, J; Komelj, M; Adamopoulos, O; Luetkens, H; Ar?on, D; Lappas, A

    2015-01-01

    Inhomogeneity in the ground state is an intriguing, emergent phenomenon in magnetism. Recently, it has been observed in the magnetostructural channel of the geometrically frustrated ?-NaMnO2, for the first time in the absence of active charge degrees of freedom. Here we report an in-depth numerical and local-probe experimental study of the isostructural sister compound CuMnO2 that emphasizes and provides an explanation for the crucial differences between the two systems. The experimentally verified, much more homogeneous, ground state of the stoichiometric CuMnO2 is attributed to the reduced magnetoelastic competition between the counteracting magnetic-exchange and elastic-energy contributions. The comparison of the two systems additionally highlights the role of disorder and allows the understanding of the puzzling phenomenon of phase separation in uniform antiferromagnets. PMID:25786810

  19. Elastic and deeply inelastic reactions in the 86Kr + 139La system at 505, 610, and 710 MeV

    Microsoft Academic Search

    R. Vandenbosch; M. P. Webb; P. Dyer; R. J. Puigh; R. Weisfield; T. D. Thomas; M. S. Zisman

    1978-01-01

    Angular and energy distributions were measured for the reaction products from the 86Kr + 139La reaction at 505, 610, and 710 MeV bombarding energies. The elastic scattering data were analyzed to extract information about the conservative potential. The strength of the potential for separations close to the strong absorption radius is in agreement with a number of theoretical potentials including

  20. Savings potential of ENERGY STAR (registered trademark) voluntary labeling programs

    SciTech Connect

    Webber, Carrie A.; Brown, Richard E.

    1998-06-19

    In 1993 the U.S. Environmental Protection Agency (EPA) introduced ENERGY STAR (registered trademark), a voluntary labeling program designed to identify and promote energy-efficient products. Since then EPA, now in partnership with the U.S. Department of Energy (DOE), has introduced programs for more than twenty products, spanning office equipment, residential heating and cooling equipment, new homes, commercial and residential lighting, home electronics, and major appliances. We present potential energy, dollar and carbon savings forecasts for these programs for the period 1998 to 2010. Our target market penetration case represents our best estimate of future ENERGY STAR savings. It is based on realistic market penetration goals for each of the products. We also provide results under the assumption of 100% market penetration; that is, we assume that all purchasers buy ENERGY STAR-compliant products instead of standard efficiency products throughout the analysis period. Finally, we assess the sensitivity of our target penetration case forecasts to greater or lesser marketing success by EPA and DOE, lower-than-expected future energy prices, and higher or lower rates of carbon emission by electricity generators. The potential savings of ENERGY STAR are substantial. If all purchasers chose Energy Star-compliant products instead of standard efficiency products over the next 15 years, they would save more than $100 billion on their energy bills during those 15 years. (Bill savings are in 1995 dollars, discounted at a 4% real discount rate.)

  1. A model for creep life prediction of thin tube using strain energy density as a function of stress triaxiality under quasistatic loading employing elastic-creep & elastic-plastic-creep deformation

    NASA Astrophysics Data System (ADS)

    Mahmood, Tahir; Kanapathipillai, Sangarapillai; Chowdhury, Mahiuddin

    2013-06-01

    This paper demonstrates the application of a new multiaxial creep damage model developed by authors using stress traixiality to predict the failure time of a component made of 0.5%Cr-0.5%Mo-0.25%V low alloy steel. The model employs strain energy density and assumes that the uniaxial strain energy density of a component can be easily calculated and can be converted to multi-axial strain energy density by multiplying it to a function of stress trixiality which is a ratio of mean stress to equivalent stress. For comparison, an elastic-creep and elastic-plastic-creep finite element analysis (FEA) is performed to get multi-axial strain energy density of the component which is compared with the calculated strain energy density for both cases. The verification and application of the model are demonstrated by applying it to thin tube for which the experimental data are available. The predicted failure times by the model are compared with the experimental results. The results show that the proposed model is capable of predicting failure times of the component made of the above-mentioned material with an accuracy of 4.0%.

  2. At-edge minima in elastic photon scattering amplitudes for dilute aqueous ions

    Microsoft Academic Search

    D. A. Bradleya; A. L. Yusoff; Guildford GU

    Elastic photon scattering and absorption in the vicinity of core atomic orbital energies give rise to resonances in the elastic photon scattering cross-section. Of interest is whether a dilute-ion aqueous system provides an environment suitable for testing independent particle approximation (IPA) predictions. Predictions of the energy of these resonances have been determined for a Dirac-Slater exchange potential with a Latter

  3. Potential energy production from algae on marginal land in China.

    PubMed

    Zhang, Qingtao; Ma, Jiong; Qiu, Guoyu; Li, Li; Geng, Shu; Hasi, E; Li, Cheng; Wang, Guangyi; Li, Xiaoyan

    2012-04-01

    This study is aimed to systematically estimate marginal land resources with different grades (total area; land with certain eco-environmental-economic feasibility; centralized reserve land) in China, and evaluate potential energy production from microalgae on marginal lands in the long-, mid- and near-term, based on a model. The annual potential energy production from algae in total marginal land of China (APEMC) was estimated to 4.19 billion standard coal equivalent (tce), far more than total annual energy consumption equivalent in China (TECCE) in 2007. For microalgae with 35% lipid content, the APEMC in the mid-term would be 37.6-65.8% of the TECCE in 2007. The corresponding annual CO(2) emission mitigation by replacement of fossil fuels by algal bioenergy would be 4.27-7.44 billiont. Although Southwest China provides the highest potential algae production in the long-term, Northwest China provides the highest value in the near-term. PMID:21945161

  4. Saturation wind power potential and its implications for wind energy.

    PubMed

    Jacobson, Mark Z; Archer, Cristina L

    2012-09-25

    Wind turbines convert kinetic to electrical energy, which returns to the atmosphere as heat to regenerate some potential and kinetic energy. As the number of wind turbines increases over large geographic regions, power extraction first increases linearly, but then converges to a saturation potential not identified previously from physical principles or turbine properties. These saturation potentials are >250 terawatts (TW) at 100 m globally, approximately 80 TW at 100 m over land plus coastal ocean outside Antarctica, and approximately 380 TW at 10 km in the jet streams. Thus, there is no fundamental barrier to obtaining half (approximately 5.75 TW) or several times the world's all-purpose power from wind in a 2030 clean-energy economy. PMID:23019353

  5. Saturation wind power potential and its implications for wind energy

    PubMed Central

    Jacobson, Mark Z.; Archer, Cristina L.

    2012-01-01

    Wind turbines convert kinetic to electrical energy, which returns to the atmosphere as heat to regenerate some potential and kinetic energy. As the number of wind turbines increases over large geographic regions, power extraction first increases linearly, but then converges to a saturation potential not identified previously from physical principles or turbine properties. These saturation potentials are >250 terawatts (TW) at 100 m globally, approximately 80 TW at 100 m over land plus coastal ocean outside Antarctica, and approximately 380 TW at 10 km in the jet streams. Thus, there is no fundamental barrier to obtaining half (approximately 5.75 TW) or several times the world’s all-purpose power from wind in a 2030 clean-energy economy. PMID:23019353

  6. Simple simulation for electron energy levels in geometrical potential wells

    E-print Network

    Pengpan, Teparksorn

    2008-01-01

    An octopus program is demonstrated to generate electron energy levels in three-dimensional geometrical potential wells. The wells are modeled to have shapes similar to cone, pyramid and truncated-pyramid. To simulate the electron energy levels in quantum mechanical scheme like the ones in parabolic band approximation scheme, the program is run initially to find a suitable electron mass fraction that can produce ground-state energies in the wells as close to those in quantum dots as possible and further to simulate excited-state energies. The programs also produce wavefunctions for exploring and determining their degeneracies and vibrational normal modes.

  7. Numerical investigation of elastic mechanical properties of graphene structures

    Microsoft Academic Search

    S. K. Georgantzinos; G. I. Giannopoulos; N. K. Anifantis

    2010-01-01

    The computation of the elastic mechanical properties of graphene sheets, nanoribbons and graphite flakes using spring based finite element models is the aim of this paper. Interatomic bonded interactions as well as van der Waals forces between carbon atoms are simulated via the use of appropriate spring elements expressing corresponding potential energies provided by molecular theory. Each layer is idealized

  8. Elastic cross sections for electron scattering from GeF4: predominance of atomic-F in the high-energy collision dynamics.

    PubMed

    Kato, H; Suga, A; Hoshino, M; Blanco, F; García, G; Limão-Vieira, P; Brunger, M J; Tanaka, H

    2012-04-01

    We report absolute differential cross sections (DCSs) for elastic electron scattering from GeF(4). The incident electron energy range was 3-200 eV, while the scattered electron angular range was typically 15°-150°. In addition, corresponding independent atom model (IAM) calculations, within the screened additivity rule (SCAR) formulation, were also performed. Those results, particularly for electron energies above about 10 eV, were found to be in good quantitative agreement with the present experimental data. Furthermore, we compare our GeF(4) elastic DCSs to similar data for scattering from CF(4) and SiF(4). All these three species possess T(d) symmetry, and at each specific energy considered above about 50 eV their DCSs are observed to be almost identical. These indistinguishable features suggest that high-energy elastic scattering from these targets is virtually dominated by the atomic-F species of the molecules. Finally, estimates for the measured GeF(4) elastic integral cross sections are derived and compared to our IAM-SCAR computations and with independent total cross section values. PMID:22482558

  9. Split Kinetic Energy Method for Quantum Systems with Competing Potentials

    E-print Network

    H. Mineo; Sheng D. Chao

    2012-06-11

    For quantum systems with competing potentials, the conventional perturbation theory often yields an asymptotic series and the subsequent numerical outcome becomes uncertain. To tackle such kind of problems, we develop a general solution scheme based on a new energy dissection idea. Instead of dividing the potential energy into "unperturbed" and "perturbed" terms, a partition of the kinetic energy is performed. By distributing the kinetic energy term in part into each individual potential, the Hamiltonian can be expressed as the sum of the subsystem Hamiltonians with respective competing potentials. The total wavefunction is expanded by using a linear combination of the basis sets of respective subsystem Hamiltonians. We first illustrate the solution procedure using a simple system consisting of a particle under the action of double delta-function potentials. Next, this method is applied to the prototype systems of a charged harmonic oscillator in strong magnetic field and the hydrogen molecule ion. Compared with the usual perturbation approach, this new scheme converges much faster to the exact solutions for both eigenvalues and eigenfunctions. When properly extended, this new solution scheme can be very useful for dealing with strongly coupling quantum systems.

  10. Split kinetic energy method for quantum systems with competing potentials

    NASA Astrophysics Data System (ADS)

    Mineo, H.; Chao, Sheng D.

    2012-09-01

    For quantum systems with competing potentials, the conventional perturbation theory often yields an asymptotic series and the subsequent numerical outcome becomes uncertain. To tackle such a kind of problems, we develop a general solution scheme based on a new energy dissection idea. Instead of dividing the potential energy into "unperturbed" and "perturbed" terms, a partition of the kinetic energy is performed. By distributing the kinetic energy term in part into each individual potential, the Hamiltonian can be expressed as the sum of the subsystem Hamiltonians with respective competing potentials. The total wavefunction is expanded by using a linear combination of the basis sets of respective subsystem Hamiltonians. We first illustrate the solution procedure using a simple system consisting of a particle under the action of double ?-function potentials. Next, this method is applied to the prototype systems of a charged harmonic oscillator in strong magnetic field and the hydrogen molecule ion. Compared with the usual perturbation approach, this new scheme converges much faster to the exact solutions for both eigenvalues and eigenfunctions. When properly extended, this new solution scheme can be very useful for dealing with strongly coupling quantum systems.

  11. Ab initio potential energy and dipole moment surfaces for CS2: determination of molecular vibrational energies.

    PubMed

    Pradhan, Ekadashi; Carreón-Macedo, José-Luis; Cuervo, Javier E; Schröder, Markus; Brown, Alex

    2013-08-15

    The ground state potential energy and dipole moment surfaces for CS2 have been determined at the CASPT2/C:cc-pVTZ,S:aug-cc-pV(T+d)Z level of theory. The potential energy surface has been fit to a sum-of-products form using the neural network method with exponential neurons. A generic interface between neural network potential energy surface fitting and the Heidelberg MCTDH software package is demonstrated. The potential energy surface has also been fit using the potfit procedure in MCTDH. For fits to the low-energy regions of the potential, the neural network method requires fewer parameters than potfit to achieve high accuracy; global fits are comparable between the two methods. Using these potential energy surfaces, the vibrational energies have been computed for the four most abundant CS2 isotopomers. These results are compared to experimental and previous theoretical data. The current potential energy surfaces are shown to accurately reproduce the low-lying vibrational energies within a few wavenumbers. Hence, the potential energy and dipole moments surfaces will be useful for future study on the control of quantum dynamics in CS2. PMID:23199237

  12. Wayside energy storage for recuperation of potential energy from freight trains

    SciTech Connect

    Lawson, L.J.; Koper, J.; Cook, L.M.

    1981-01-01

    The subject of this paper, involves the potential for use of a wayside energy storage system to recapture part of the braking energy normally dissipated on long descending grades by freight trains employing dynamic braking. 4 refs.

  13. Assessment of wind energy potential in Gaza Strip

    Microsoft Academic Search

    Juma Yousuf Alaydi

    2011-01-01

    The analysis of collected wind data at two sites in the Gaza Strip, namely, Gaza City and Gaza International Airport in Rafah\\u000a city, is presented. The two sites are candidates for remote area wind energy applications. The purpose of this paper is to\\u000a present the results of the assessment of wind energy potential in the Gaza Strip in order to

  14. Reference pressure changes and available potential energy in isobaric coordinates

    NASA Technical Reports Server (NTRS)

    Robertson, F. R.

    1985-01-01

    A formulation of the available potential energy (APE) equation in isobaric coordinates which alleviates the need for computing temporal derivatives of reference pressure and describes how work done relates to changes in the APE of a limited region is presented. The APE budget equation possesses terms analogous to those in Johnson's (1970) isentropic version. It is shown that APE changes result from either mechanical work inside the domain or an exchange of energy via boundary processes with the surrounding environment.

  15. Potential Energy Functions for Transition Metals and Their Aluminides

    NASA Astrophysics Data System (ADS)

    Zou, Jun

    Transition metal aluminides have a wide range of potential uses in applications requiring high strength and light weight. Obtaining accurate potential energy functions is the first step in trying to understand the structural and defect properties of these materials. Using the simple Anderson model and ab-initio results as inputs, we are able to derive strong medium- and long-ranged interactions among the transition metal atoms in aluminides. Treating the pseudopotentials as a perturbation, we obtain a complete set of pair potentials for any pair of atoms in the aluminides. These potentials agree well with experiments on the structure of liquid aluminides, predict the correct chemical trends in structural stability, and in most cases reproduce the large structural energy differences that have been demonstrated by ab-initio calculations. The calculated results on the structural energies agree fairly well with the experimental phase diagram and the existing ab-initio results. On the basis of these potentials, we propose an explanation for quasicrystal formation in the aluminides. Four-body angular forces recently developed by Carlsson are used in the molecular dynamics simulation of liquid W to examine the effect of angular forces on the structure and thermodynamic properties of the liquid. We do not find any significant effect of the angular forces as compared with radial interatomic forces. However, the angular forces are much more accurate overall in treating the thermodynamic properties.

  16. Transit price elasticities and cross-elasticities

    Microsoft Academic Search

    Todd Litman

    2007-01-01

    This paper summarises price elasticities and cross elasticities for use in public transit planning. It describes how elasticities are used, and summarizes previous research on transit elasticities. Commonly used transit elasticity values are largely based on studies of short and medium run impacts performed decades ago when real incomes were lower and a larger portion of the population was transit

  17. Computing Molecular Potential Energy Surface with DIET Emmanuel Jeannot

    E-print Network

    Jeannot, Emmanuel

    Computing Molecular Potential Energy Surface with DIET Emmanuel Jeannot LORIA ­ Universit´e Henri tackled this problem using several up-to-date computer science technology such as grid-computing middleware, molecular databases, script interfacing, etc. An example on the optimization of semiem- pirical

  18. Potential energy curves for the Zn 2 dimer

    Microsoft Academic Search

    E. Czuchaj; F. Rebentrost; H. Stoll; H. Preuss

    1996-01-01

    MRCI(SD) calculations have been performed for the adiabatic potential curves and dipole transition moments of diatomic zinc. Only the four valence electrons of the system are treated explicitly, whereas the atomic cores are replaced by the energy-adjusted pseudopotentials. The spin-orbit coupling has not been considered.

  19. Estimation of wind energy potential using different probability density functions

    Microsoft Academic Search

    Tian Pau Chang

    2011-01-01

    In addition to the probability density function (pdf) derived with maximum entropy principle (MEP), several kinds of mixture probability functions have already been applied to estimate wind energy potential in scientific literature, such as the bimodal Weibull function (WW) and truncated Normal Weibull function (NW). In this paper, two other mixture functions are proposed for the first time to wind

  20. Framework for State-Level Renewable Energy Market Potential Studies

    Microsoft Academic Search

    Claire Kreycik; Laura Vimmerstedt; Elizabeth Doris

    2010-01-01

    State-level policymakers are relying on estimates of the market potential for renewable energy resources as they set goals and develop policies to accelerate the development of these resources. Therefore, accuracy of such estimates should be understood and possibly improved to appropriately support these decisions. This document provides a framework and next steps for state officials who require estimates of renewable

  1. The Potential for Wind Energy in Atlantic Canada

    E-print Network

    Hughes, Larry

    Canada 1 The Potential for Wind Energy in Atlantic Canada Abstract Canadians are among the highest per of a software tool that permits the modelling of wind turbines and wind farms, the paper shows that wind from three sources: Environment Canada (wind data for Atlantic Canada) Test Station for Windmills

  2. Unified Technical Concepts. Module 7: Potential and Kinetic Energy.

    ERIC Educational Resources Information Center

    Technical Education Research Center, Waco, TX.

    This concept module on potential and kinetic energy is one of thirteen modules that provide a flexible, laboratory-based physics instructional package designed to meet the specialized needs of students in two-year, postsecondary technical schools. Each of the thirteen concept modules discusses a single physics concept and how it is applied to each…

  3. Evaluation of exchange-correlation energy, potential, and stress

    Microsoft Academic Search

    L. C. Balbás; José Luís Martins; José M. Soler

    2001-01-01

    We describe a method for calculating the exchange and correlation (XC) contributions to the total energy, effective potential, and stress tensor in the generalized gradient approximation. We avoid using the analytical expressions for the functional derivatives of Exc[rho], which depend on discontinuous second-order derivatives of the electron density rho. Instead, we first approximate Exc by its integral in a real

  4. Low energy chiral two pion exchange potential with statistical uncertainties

    E-print Network

    R. Navarro Perez; J. E. Amaro; E. Ruiz Arriola

    2015-05-12

    We present a new phenomenological Nucleon-Nucleon chiral potential fitted to 925 pp and 1743 np scattering data selected from the Granada-2013 NN-database up to a laboratory energy of $125$ MeV with 20 short distance parameters and three chiral constants $c_1$, $c_3$ and $c_4$ with $\\chi^2/\

  5. LHC Physics Potential vs. Energy: Considerations for the 2011 Run

    SciTech Connect

    Quigg, Chris; /Fermilab /CERN

    2011-02-01

    Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I quantify the advantage of increasing the beam energy from 3.5 TeV to 4 TeV. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u {bar d}, qq, and gq interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes. This note extends the analysis presented in Ref. [1]. Full-size figures are available as pdf files at lutece.fnal.gov/PartonLum11/.

  6. Renewable energy technologies adoption in Kazakhstan: potentials, barriers and solutions

    NASA Astrophysics Data System (ADS)

    Karatayev, Marat; Marazza, Diego; Contin, Andrea

    2015-04-01

    The growth in environmental pollution alongside an increasing demand for electricity in Kazakhstan calls for a higher level of renewable energy penetration into national power systems. Kazakhstan has great potential for renewable energies from wind, solar, hydro and biomass resources that can be exploited for electricity production. In 2013, the Kazakhstani Ministry of Energy initiated a new power development plan, which aims to bring the share of renewable energy to 3% by 2020 rising to 30% by 2030 and 50% by 2050. The current contribution of renewable energy resources in the national electricity mix, however, is less than 1%. As a developing country, Kazakhstan has faced a number of barriers to increase renewable energy use, which have to be analysed and translated into a comprehensive renewable energy policy framework. This study presents an overview of the current conditions of renewable energy development in Kazakhstan. Secondly, it identifies and describes the main barriers that prevent diffusion of renewable energy technologies in Kazakhstan. Finally, the paper provides solutions to overcome specific barriers in order to successfully develop a renewable energy technology sector in Kazakhstan.

  7. Understanding Potential Climate Variability Impacts on the Offshore Energy Industry

    NASA Astrophysics Data System (ADS)

    Stear, J.

    2014-12-01

    Climate variability may have important implications for the offshore energy industry. Scenarios of increased storm activity and changes in sea level could require the retrofit of existing offshore platforms and coastal infrastructure, the decommissioning of facilities for which upgrade or relocation is not economically viable, and the development of new methods and equipment which are removed from or less sensitive to environmental loads. Over the past years the energy industry has been actively involved in collaborative research efforts with government and academia to identify the potential changes in the offshore operating environment, and corresponding risk implications. This presentation will review several of these efforts, and for several of the hypothetical climate variation scenarios, review the potential impacts on and possible mitigations for offshore and coastal energy infrastructure and operations.

  8. Turkey's High Temperature Geothermal Energy Resources and Electricity Production Potential

    NASA Astrophysics Data System (ADS)

    Bilgin, Ö.

    2012-04-01

    Turkey is in the first 7 countries in the world in terms of potential and applications. Geothermal energy which is an alternative energy resource has advantages such as low-cost, clean, safe and natural resource. Geothermal energy is defined as hot water and steam which is formed by heat that accumulated in various depths of the Earth's crust; with more than 20oC temperature and which contain more than fused minerals, various salts and gases than normal underground and ground water. It is divided into three groups as low, medium and high temperature. High-temperature fluid is used in electricity generation, low and medium temperature fluids are used in greenhouses, houses, airport runways, animal farms and places such as swimming pools heating. In this study high temperature geothermal fields in Turkey which is suitable for electricity production, properties and electricity production potential was investigated.

  9. Heterobarrier for converting hot-phonon energy to electric potential

    NASA Astrophysics Data System (ADS)

    Shin, Seungha; Melnick, Corey; Kaviany, Massoud

    2013-02-01

    We show that hot phonons emitted in energy conversion or resistive processes can be converted to electric potential in heterobarrier structures. Using phonon and electron interaction kinetics and self-consistent ensemble Monte Carlo, we find the favorable conditions for unassisted absorption of hot phonons and design graded heterobarriers for their direct conversion into electric energy. Tandem barriers with nearly optical-phonon height allow for substantial potential gain without current loss. We find that 19% of hot phonons can be harvested with an optimized GaAs/AlxGa1-xAs barrier structure over a range of current and electron densities, thus enhancing the overall energy conversion efficiency and reducing waste heat.

  10. N2(+) bound quartet and sextet state potential energy curves

    NASA Technical Reports Server (NTRS)

    Partridge, H.; Bauschlicher, C. W., Jr.; Stallcop, J. R.

    1985-01-01

    The N2(+) potential energies have been determined from a complete active space self-consistent field calculation with active 2s and 2p electrons. A (6s 4p 3d 1f) Gaussian basis set was used together with additional higher angular momentum and diffuse functions. The calculated potential energy curves for the states 4Sigma(mu)(+), 4Pi(g), and 6Sigma(g)(+), for which there are no spectroscopic observations, are presented. The corresponding spectroscopic constants have been determined from a polynomial curve fit to the computed energies near the well minima and are shown. The 6Sigma(g)(+) state is found to be significantly bound, with a minimum at 1.72 A.

  11. Global Potential of Energy Efficiency Standards and Labeling Programs

    SciTech Connect

    McNeil, Michael A; McNeil, Michael A.; Letschert, Virginie; de la Rue du Can, Stephane

    2008-06-15

    This report estimates the global potential reductions in greenhouse gas emissions by 2030 for energy efficiency improvements associated with equipment (appliances, lighting, and HVAC) in buildings by means of energy efficiency standards and labels (EES&L). A consensus has emerged among the world's scientists and many corporate and political leaders regarding the need to address the threat of climate change through emissions mitigation and adaptation. A further consensus has emerged that a central component of these strategies must be focused around energy, which is the primary generator of greenhouse gas emissions. Two important questions result from this consensus: 'what kinds of policies encourage the appropriate transformation to energy efficiency' and 'how much impact can these policies have'? This report aims to contribute to the dialogue surrounding these issues by considering the potential impacts of a single policy type, applied on a global scale. The policy addressed in this report is Energy Efficient Standards and Labeling (EES&L) for energy-consuming equipment, which has now been implemented in over 60 countries. Mandatory energy performance standards are important because they contribute positively to a nation's economy and provide relative certainty about the outcome (both timing and magnitudes). Labels also contribute positively to a nation's economy and importantly increase the awareness of the energy-consuming public. Other policies not analyzed here (utility incentives, tax credits) are complimentary to standards and labels and also contribute in significant ways to reducing greenhouse gas emissions. We believe the analysis reported here to be the first systematic attempt to evaluate the potential of savings from EES&L for all countries and for such a large set of products. The goal of the analysis is to provide an assessment that is sufficiently well-quantified and accurate to allow comparison and integration with other strategies under consideration.

  12. Analysis of energy dissipation and deposition in elastic bodies impacting at hypervelocities

    NASA Technical Reports Server (NTRS)

    Medina, David F.; Allahdadi, Firooz A.

    1992-01-01

    A series of impact problems were analyzed using the Eulerian hydrocode CTH. The objective was to quantify the amount of energy dissipated locally by a projectile-infinite plate impact. A series of six impact problems were formulated such that the mass and speed of each projectile were varied in order to allow for increasing speed with constant kinetic energy. The properties and dimensions of the plate were the same for each projectile impact. The resulting response of the plate was analyzed for global Kinetic Energy, global momentum, and local maximum shear stress. The percentage of energy dissipated by the various hypervelocity impact phenomena appears as a relative change of shear stress at a point away from the impact in the plate.

  13. Energy gap in graphene nanoribbons with structured external electric potentials

    NASA Astrophysics Data System (ADS)

    Apel, W.; Pal, G.; Schweitzer, L.

    2011-03-01

    The electronic properties of graphene zigzag nanoribbons with electrostatic potentials along the edges are investigated. Using the Dirac-fermion approach, we calculate the energy spectrum of an infinitely long nanoribbon of finite width w, terminated by Dirichlet boundary conditions in the transverse direction. We show that a structured external potential that acts within the edge regions of the ribbon can induce a spectral gap and thus switch the nanoribbon from metallic to insulating behavior. The basic mechanism of this effect is the selective influence of the external potentials on the spinorial wave functions that are topological in nature and localized along the boundary of the graphene nanoribbon. Within this single-particle description, the maximal obtainable energy gap is Emax???vF/w, i.e., ?0.12 eV for w=15 nm. The stability of the spectral gap against edge disorder and the effect of disorder on the two-terminal conductance is studied numerically within a tight-binding lattice model. We find that the energy gap persists as long as the applied external effective potential is larger than ?0.55×W, where W is a measure of the disorder strength. We argue that there is a transport gap due to localization effects even in the absence of a spectral gap.

  14. Evaluation of global onshore wind energy potential and generation costs.

    PubMed

    Zhou, Yuyu; Luckow, Patrick; Smith, Steven J; Clarke, Leon

    2012-07-17

    In this study, we develop an updated global estimate of onshore wind energy potential using reanalysis wind speed data, along with updated wind turbine technology performance, land suitability factors, cost assumptions, and explicit consideration of transmission distance in the calculation of transmission costs. We find that wind has the potential to supply a significant portion of the world energy needs, although this potential varies substantially by region and with assumptions such as on what types of land can be used to site wind farms. Total global economic wind potential under central assumptions, that is, intermediate between optimistic and pessimistic, is estimated to be approximately 119.5 petawatt hours per year (13.6 TW) at less than 9 cents/kWh. A sensitivity analysis of eight key parameters is presented. Wind potential is sensitive to a number of input parameters, particularly wind speed (varying by -70% to +450% at less than 9 cents/kWh), land suitability (by -55% to +25%), turbine density (by -60% to +80%), and cost and financing options (by -20% to +200%), many of which have important policy implications. As a result of sensitivities studied here we suggest that further research intended to inform wind supply curve development focus not purely on physical science, such as better resolved wind maps, but also on these less well-defined factors, such as land-suitability, that will also have an impact on the long-term role of wind power. PMID:22715929

  15. U.S. Building-Sector Energy Efficiency Potential

    SciTech Connect

    Brown, Rich; Borgeson, Sam; Koomey, Jon; Biermayer, Peter

    2008-09-30

    This paper presents an estimate of the potential for energy efficiency improvements in the U.S. building sector by 2030. The analysis uses the Energy Information Administration's AEO 2007 Reference Case as a business-as-usual (BAU) scenario, and applies percentage savings estimates by end use drawn from several prior efficiency potential studies. These prior studies include the U.S. Department of Energy's Scenarios for a Clean Energy Future (CEF) study and a recent study of natural gas savings potential in New York state. For a few end uses for which savings estimates are not readily available, the LBNL study team compiled technical data to estimate savings percentages and costs of conserved energy. The analysis shows that for electricity use in buildings, approximately one-third of the BAU consumption can be saved at a cost of conserved energy of 2.7 cents/kWh (all values in 2007 dollars), while for natural gas approximately the same percentage savings is possible at a cost of between 2.5 and 6.9 $/million Btu. This cost-effective level of savings results in national annual energy bill savings in 2030 of nearly $170 billion. To achieve these savings, the cumulative capital investment needed between 2010 and 2030 is about $440 billion, which translates to a 2-1/2 year simple payback period, or savings over the life of the measures that are nearly 3.5 times larger than the investment required (i.e., a benefit-cost ratio of 3.5).

  16. A global potential energy surface for ArH2

    NASA Technical Reports Server (NTRS)

    Schwenke, David W.; Walch, Stephen P.; Taylor, Peter R.

    1992-01-01

    We describe a simple analytic representation of the ArH2 potential energy surface which well reproduces the results of extensive ab initio electronic structure calculations. The analytic representation smoothly interpolates between the dissociated H2 and strong bonding limits. In the fitting process, emphasis is made on accurately reproducing regions of the potential expected to be important for high temperature (ca. 3000 K) collision processes. Overall, the anisotropy and H2 bond length dependence of the analytic representation well reproduce the input data.

  17. NVU dynamics. III. Simulating molecules at constant potential energy

    NASA Astrophysics Data System (ADS)

    Ingebrigtsen, Trond S.; Dyre, Jeppe C.

    2012-12-01

    This is the final paper in a series that introduces geodesic molecular dynamics at constant potential energy. This dynamics is entitled NVU dynamics in analogy to standard energy-conserving Newtonian NVE dynamics. In the first two papers [T. S. Ingebrigtsen, S. Toxvaerd, O. J. Heilmann, T. B. Schrøder, and J. C. Dyre, J. Chem. Phys. 135, 104101 (2011), 10.1063/1.3623585; T. S. Ingebrigtsen, S. Toxvaerd, T. B. Schrøder, and J. C. Dyre, J. Chem. Phys. 135, 104102 (2011), 10.1063/1.3623586], a numerical algorithm for simulating geodesic motion of atomic systems was developed and tested against standard algorithms. The conclusion was that the NVU algorithm has the same desirable properties as the Verlet algorithm for Newtonian NVE dynamics, i.e., it is time-reversible and symplectic. Additionally, it was concluded that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit. In this paper, the NVU algorithm for atomic systems is extended to be able to simulate the geodesic motion of molecules at constant potential energy. We derive an algorithm for simulating rigid bonds and test this algorithm on three different systems: an asymmetric dumbbell model, Lewis-Wahnström o-terphenyl (OTP) and rigid SPC/E water. The rigid bonds introduce additional constraints beyond that of constant potential energy for atomic systems. The rigid-bond NVU algorithm conserves potential energy, bond lengths, and step length for indefinitely long runs. The quantities probed in simulations give results identical to those of Nosé-Hoover NVT dynamics. Since Nosé-Hoover NVT dynamics is known to give results equivalent to those of NVE dynamics, the latter results show that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit also for molecular systems.

  18. NVU dynamics. III. Simulating molecules at constant potential energy.

    PubMed

    Ingebrigtsen, Trond S; Dyre, Jeppe C

    2012-12-28

    This is the final paper in a series that introduces geodesic molecular dynamics at constant potential energy. This dynamics is entitled NVU dynamics in analogy to standard energy-conserving Newtonian NVE dynamics. In the first two papers [T. S. Ingebrigtsen, S. Toxvaerd, O. J. Heilmann, T. B. Schrøder, and J. C. Dyre, J. Chem. Phys. 135, 104101 (2011); T. S. Ingebrigtsen, S. Toxvaerd, T. B. Schrøder, and J. C. Dyre, ibid. 135, 104102 (2011)], a numerical algorithm for simulating geodesic motion of atomic systems was developed and tested against standard algorithms. The conclusion was that the NVU algorithm has the same desirable properties as the Verlet algorithm for Newtonian NVE dynamics, i.e., it is time-reversible and symplectic. Additionally, it was concluded that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit. In this paper, the NVU algorithm for atomic systems is extended to be able to simulate the geodesic motion of molecules at constant potential energy. We derive an algorithm for simulating rigid bonds and test this algorithm on three different systems: an asymmetric dumbbell model, Lewis-Wahnström o-terphenyl (OTP) and rigid SPC/E water. The rigid bonds introduce additional constraints beyond that of constant potential energy for atomic systems. The rigid-bond NVU algorithm conserves potential energy, bond lengths, and step length for indefinitely long runs. The quantities probed in simulations give results identical to those of Nosé-Hoover NVT dynamics. Since Nose?-Hoover NVT dynamics is known to give results equivalent to those of NVE dynamics, the latter results show that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit also for molecular systems. PMID:23277922

  19. Energy consumption and energy efficiency retrofit potential for government office buildings in Beijing

    Microsoft Academic Search

    Wei Cai; Jian Yang; Huang Wang; Jiao Huang

    2012-01-01

    The purpose of this study is to investigate the energy consumption characteristics of government office buildings in Beijing. Four office buildings were chosen to analyze the energy consumption features and annual energy consumption trends. Energy efficiency potential of government office buildings were analyzed from the six perspectives. The results show that the air conditioning energy consumption was 25.9 kwh\\/m2·a, accounted

  20. Search for dark energy potentials in quintessence theory

    E-print Network

    Muromachi, Yusuke; Okada, Daiki; Hara, Tetsuya; Itoh, Yutaka

    2015-01-01

    The time evolution of the equation of state $w$ for quintessence models with a scalar field as dark energy is studied up to the third derivative ($d^3w/da^3$) with respect to scale factor $a$, in order to predict the future observations and specify the scalar potential parameters with the observables. The third derivative of $w$ for general potential $V$ was derived and applied to several types of potential. They are the inverse power-law ($V=M^{4+\\alpha}/Q^{\\alpha}$), exponential ($V=M^4\\exp{(\\beta M/Q)}$), mixed ( $V=M^{4+\\gamma}\\exp{(\\beta M/Q)}/Q^{\\gamma}$), cosine ($V=M^4(\\cos (Q/f)+1)$) and the Gaussian types ($V=M^4\\exp(-Q^2/\\sigma^2)$), which are prototypical potentials for the freezing and thawing models. If the parameter number for a potential form is $ n$, it is necessary to find at least for $n+2$ independent observations to identify the potential form and the evolution of scalar field ($Q$ and $ \\dot{Q} $). Such observations would be the values of $ \\Omega_Q, w, dw/da. \\cdots $, and $ dw^n/da^n$....

  1. Dynamics of elastic and inelastic energy transfer between quantum dots in a microcavity

    NASA Astrophysics Data System (ADS)

    Xu, K. J.; Piermarocchi, C.

    2011-09-01

    We develop a theory of exciton energy transfer dynamics between two quantum dots in a planar microcavity. We study the dynamics of quantum dot excitons in three different cases: (i) a single dot coupled only to cavity modes, (ii) two dots coupled to cavity modes, and (iii) two dots coupled to cavity modes and to acoustic phonons. In the latter case, we focus on the process of phonon-assisted inelastic exciton energy transfer between the quantum dots. We take into account phonon effects by introducing a light-matter Hamiltonian with operators describing the exciton-photon-phonon coupling and we truncate the Hilbert space by assuming that at most one excitation is present in the system. Using this approach we simulate the exciton dynamics with realistic parameters in the zero temperature limit. From the dynamics we extract the dependence of the characteristic energy transfer rate as a function of the interdot separation. This theoretical approach can be used to optimize exciton energy transfer by designing structures with engineered photon and phonon density of states.

  2. Magnetoelastic formulation of soft ferromagnetic elastic problems with collinear cracks: energy density fracture criterion

    Microsoft Academic Search

    W. Liang; Y. P. Shen; M. Zhao

    2000-01-01

    Magnetoelasticity is applied to solve collinear crack problems for soft ferromagnetic materials in two dimension. Complex functions are used for reducing the problem to the solution of a system of singular integral equations. The energy density factors are derived for determining how an off-axis magnetic field without mechanical load would influence the direction of crack initiation. The critical conditions are

  3. Minimal energy for elastic inclusions By Hans Knupfer and Robert V. Kohn

    E-print Network

    . This problem has been studied extensively in the physical/metallurgical literature; however, the analysis has.g. ellipsoids. In this article we prove a lower bound for the energy, with no a priori hypothesis on the shape in the physical/metallurgical literature. However, in this literature, the analysis has mainly been either (i) nu

  4. Measurement of elastic 12C + ? scattering: Above the proton separation energy

    NASA Astrophysics Data System (ADS)

    deBoer, R. J.; Couture, A.; Detwiler, R.; Görres, J.; Tischhauser, P.; Uberseder, E.; Ugalde, C.; Stech, E.; Wiescher, M.; Azuma, R. E.

    2012-04-01

    Background: Reactions that probe the compound nucleus structure of 16O near the ? and proton separation energies have important implications for nuclear astrophysics. New, more sensitive measurements of the reaction 15N(p,?)16O have motivated the need for improved compound-nucleus reaction data in other channels. A previous work [P. Tischhauser , Phys. Rev. C 79, 055803 (2009)] reported extensive ?-scattering data over the energy region from E?=2.6 to E?=6.6 MeV. During this experiment data for higher energies, from E?=6.6 to E?=8.2 MeV, were also recorded but were not analyzed. The unpublished data cover the excitation energy range from the proton separation energy at Ex = 12.13 MeV up to 13.31 MeV, the same energy range important for the reaction 15N(p,?)16O.Purpose: These previously unpublished data for 12C(?,?)12C as well as the reactions 12C(?,?1)12C and 12C(?,p)15N are analyzed in order to provide additional data for a comprehensive R-matrix analysis of compound-nucleus reactions populating 16O.Methods: Expanding on the previous publication's analysis, the ratio of the reaction yields was analyzed using a multiple-channel R-matrix calculation.Results: The excitation curves resolved resonances at E? (J?)=7.05(1-), 7.75 (2+), 7.91 (1-), 7.97 (3-), and 8.13 (3-) MeV. The R-matrix analysis revealed excellent agreement between the measured yield ratios and cross-section data from the literature. The two 1- levels at E?=7.05 and 7.91 MeV are those that dominate the 15N(p,?)16O cross section.Conclusions: In a future publication, the additional constraints provided by these data will be used in a comprehensive multiple-channel R-matrix analysis to investigate the low-energy cross section of the reaction 15N(p,?)16O.

  5. Parallel unconstrained minimization of potential energy in LAMMPS

    SciTech Connect

    Plantenga, T.

    1997-10-13

    This report describes a new minimization capability added to LAMMPS V4.0. Minimization of potential energy is used to find molecular conformations that are close to structures found in nature. The new minimization algorithm uses LAMMPS subroutines for calculating energy and force vectors, and follows the LAMMPS partitioning scheme for distributing large data objects on multiprocessor machines. Since gradient-based algorithms cannot tolerate nonsmoothness, a new Coulomb style that smoothly cuts off to zero at a finite distance is provided. This report explains the minimization algorithm and its parallel implementation within LAMMPS. Guidelines are given for invoking the algorithm and interpreting results.

  6. Using peat for energy: Potential environmental restraints. Overview

    NASA Astrophysics Data System (ADS)

    Reed, R. M.; Voorhees, L. D.; Mulholland, P. J.

    Serious consideration is being given to using peat as an energy resource in Minnesota, North Carolina, Florida, and some New England States. Potential environmental constraints for using peat as an energy resource are associated with disruption of important regional wetland ecosystems. Mining peatlands may significantly modify ground and surface water hydrology, degrade water quality in downstream receiving systems, contribute to the deterioration of local air quality, disrupt or eliminate plant and animal populations having specialized requirements and limited distributions, and destroy unique wetland ecosystems representing important scientific and educational resources. Careful selection of peatlands to be developed and application of appropriate mitigation and monitoring programs will be necessary to offset these impacts.

  7. Quintom dark energy models with nearly flat potentials

    SciTech Connect

    Setare, M. R.; Saridakis, E. N. [Department of Science, Payame Noor University, Bijar (Iran, Islamic Republic of); Department of Physics, University of Athens, GR-15771 Athens (Greece)

    2009-02-15

    We examine quintom dark energy models, produced by the combined consideration of a canonical and a phantom field, with nearly flat potentials and dark energy equation-of-state parameter w{sub DE} close to -1. We find that all such models converge to a single expression for w{sub DE}(z), depending only on the initial field values and their derivatives. We show that this quintom paradigm allows for a description of the transition through -1 in the near cosmological past. In addition, we provide the necessary conditions for the determination of the direction of the -1 crossing.

  8. Role of the Clean Energy Potential for Energy Savings and Air Pollution Control in Turkey

    Microsoft Academic Search

    KAM?L KAYGUSUZ; HULUS? KARGI ABDULLAH KAYGUSUZ; A. Kaygusuz

    1996-01-01

    This article begins with a brief review of the technical potential, the regional distribution, and the air pollution effects of all fossil energy sources as well as of all clean and renewable energy sources that could be used in Turkey. Air pollution levels due to fossil fuel consumption are examined. In this context, the role of clean energy sources is

  9. An energy-saving oil drilling rig for recovering potential energy and decreasing motor power

    Microsoft Academic Search

    Lujun Zhang

    2011-01-01

    An energy-saving oil drilling rig is researched. A large accumulator is adopted in this rig to store the energy of the motor during the auxiliary time of lifting the drill stem and the potential energy of the drill stem when lowered. The equipped power of this rig decreases remarkably compared with the conventional drilling rig, and this rig can also

  10. Nuclear momentum distribution and potential energy surface in hexagonal ice

    NASA Astrophysics Data System (ADS)

    Lin, Lin; Morrone, Joseph; Car, Roberto; Parrinello, Michele

    2011-03-01

    The proton momentum distribution in ice Ih has been recently measured by deep inelastic neutron scattering and calculated from open path integral Car-Parrinello simulation. Here we report a detailed investigation of the relation between momentum distribution and potential energy surface based on both experiment and simulation results. The potential experienced by the proton is largely harmonic and characterized by 3 principal frequencies, which can be associated to weighted averages of phonon frequencies via lattice dynamics calculations. This approach also allows us to examine the importance of quantum effects on the dynamics of the oxygen nuclei close to the melting temperature. Finally we quantify the anharmonicity that is present in the potential acting on the protons. This work is supported by NSF and by DOE.

  11. Estimation of wind energy potential using finite mixture distribution models

    Microsoft Academic Search

    Sinan Akpinar; Ebru Kavak Akpinar

    2009-01-01

    In this paper has been investigated an analysis of wind characteristics of four stations (Elazig, Elazig-Maden, Elazig-Keban, and Elazig-Agin) over a period of 8 years (1998–2005). The probabilistic distributions of wind speed are a critical piece of information needed in the assessment of wind energy potential, and have been conventionally described by various empirical correlations. Among the empirical correlations, there

  12. MCSCF potential energy surface for photodissociation of formaldehyde

    NASA Technical Reports Server (NTRS)

    Jaffe, R. L.; Morokuma, K.

    1976-01-01

    The ground state potential energy surface for the dissociation of formaldehyde (H2CO to H2 and CO) is calculated with the ab initio MCSCF method with an extended (4-31G) basis set. The location, barrier height, and force constants of the transition state are determined, and the normal coordinate analysis is carried out. The calculated barrier height is 4.5 eV. Based on the calculated quantities, the detailed mechanism of the photochemical dissociation is discussed.

  13. Vibration–Translational Energy Transfer According to the Morse Potential

    Microsoft Academic Search

    Samuel L. Thompson

    1968-01-01

    A quantum-mechanical analysis of molecular vibration–translational motion energy transfer is obtained using the Morse potential, a one-dimensional model, and the method of distorted waves. All wavefunctions and transition matrix elements are obtained in closed form. In the limit of high temperatures, the results are identical to the Landau–Teller expression. At low temperatures, resonances are found to result from the attractive

  14. Evaluation of exchange-correlation energy, potential, and stress

    Microsoft Academic Search

    L. Balbás; Jose Luis Martins; Jose M. Soler

    2001-01-01

    We describe a method for calculating the exchange and correlation (XC)\\u000acontributions to the total energy, effective potential, and stress tensor in\\u000athe generalized gradient approximation. We avoid using the analytical\\u000aexpressions for the functional derivatives of E_xc*rho, which depend on\\u000adiscontinuous second-order derivatives of the electron density rho. Instead, we\\u000afirst approximate E_xc by its integral in a real

  15. Evaluation of Global Onshore Wind Energy Potential and Generation Costs

    SciTech Connect

    Zhou, Yuyu; Luckow, Patrick; Smith, Steven J.; Clarke, Leon E.

    2012-06-20

    In this study, we develop an updated global estimate of onshore wind energy potential using reanalysis wind speed data, along with updated wind turbine technology performance and cost assumptions as well as explicit consideration of transmission distance in the calculation of transmission costs. We find that wind has the potential to supply a significant portion of world energy needs, although this potential varies substantially by region as well as with assumptions such as on what types of land can be used to site wind farms. Total global wind potential under central assumptions is estimated to be approximately 89 petawatt hours per year at less than 9 cents/kWh with substantial regional variations. One limitation of global wind analyses is that the resolution of current global wind speed reanalysis data can result in an underestimate of high wind areas. A sensitivity analysis of eight key parameters is presented. Wind potential is sensitive to a number of input parameters, particularly those related to land suitability and turbine density as well as cost and financing assumptions which have important policy implications. Transmission cost has a relatively small impact on total wind costs, changing the potential at a given cost by 20-30%. As a result of sensitivities studied here we suggest that further research intended to inform wind supply curve development focus not purely on physical science, such as better resolved wind maps, but also on these less well-defined factors, such as land-suitability, that will also have an impact on the long-term role of wind power.

  16. Exact Energy and Momentum Conserving Algorithms for General Models in Nonlinear Elasticity

    Microsoft Academic Search

    O. Gonzalez

    1999-01-01

    Implicit time integration schemes that inherit the conservation laws of total energy, linear and angular momentum are considered for initial boundary-value problems in finite-deformation elastodynamics. Conserving schemes are constructed for gen- eral hyperelastic material models, both compressible and incompressible, and are formulated in a way that is independent of spatial discretization. Three numerical examples for Ogden-type material models, implemented using

  17. Exact energy and momentum conserving algorithms for general models in nonlinear elasticity

    Microsoft Academic Search

    O. Gonzalez

    2000-01-01

    Implicit time integration schemes that inherit the conservation laws of total energy, linear and angular momentum are considered for initial boundary-value problems in finite-deformation elastodynamics. Conserving schemes are constructed for general hyperelastic material models, both compressible and incompressible, and are formulated in a way that is independent of spatial discretization. Three numerical examples for Ogden-type material models, implemented using a

  18. Potential for luminosity improvement for low-energy RHIC operation

    SciTech Connect

    Fedotov A. V.

    2012-05-20

    At the Brookhaven National Laboratory, a physics program, motivated by the search of the QCD phase transition critical point, requires operation of the Relativistic Heavy Ion Collider (RHIC) with heavy ions at very low beam energies corresponding to 2.5-20 GeV/n. Several physics runs were already successfully performed at these low energies. However, the luminosity is very low at lowest energies of interest (< 10 GeV/n) limited by the intra-beam scattering and space-charge, as well as by machine nonlinearities. At these low energies, electron cooling could be very effective in counteracting luminosity degradation due to the IBS, while it is less effective against other limitations. Overall potential luminosity improvement for low-energy RHIC operation from cooling is summarized for various energies, taking into account all these limitations as well as beam lifetime measured during the low-energy RHIC runs. We also explore a possibility of further luminosity improvement under the space-charge limitation.

  19. The effect of the new nucleon-nucleus elastic scattering data in LAHET{trademark} Version 2.8 on neutron displacement cross section calculations

    SciTech Connect

    Pitcher, E.J.; Ferguson, P.D.; Russell, G.J.; Prael, R.E.; Madland, D.G.; Court, J.D.; Daemen, L.L. [Los Alamos National Lab., NM (United States); Wechsler, M.S. [North Carolina State Univ., Raleigh, NC (United States)

    1997-10-01

    The latest release of the medium-energy Monte Carlo transport code LAHET includes a new nucleon-nucleus elastic scattering treatment based on a global medium-energy phenomenological optical-model potential. Implementation of this new model in LAHET allows nuclear elastic scattering for neutrons with energies greater than 15 MeV and for protons with energies greater than 50 MeV. Previous investigations on the impact of the new elastic scattering data revealed that the addition of the proton elastic scattering channel can lead to a significant increase in the calculated damage energy under certain conditions. The authors report here results on the impact of the new elastic scattering data on calculated displacement cross sections in various elements for neutrons with energies in the range 16 to 3,160 MeV. Calculated displacement cross sections at 20 MeV in low-mass materials are in better agreement with SPECTER-calculated cross sections.

  20. Scanning the BFKL pomeron in elastic production of vector mesons at HERA

    Microsoft Academic Search

    J. Nemchik; B. G. Zakharov; L. D. Landau

    1994-01-01

    Elastic production of vector mesons $\\\\gamma^{*} N\\\\to V N$ is the\\u000apomeron-exchange dominated diffractive reaction with much potential of probing\\u000athe BFKL pomeron. The BFKL pomeron can conveniently be described in terms of\\u000athe dipole cross section which is a solution of the generalized BFKL equation.\\u000aIn this paper we discuss, how the energy and $Q^{2}$ dependence of elastic\\u000aproduction

  1. Differential, total, and transport cross sections for elastic scattering of low energy positrons by neutral atoms (Z = 1--92, E = 500--4000 eV)

    SciTech Connect

    Dapor, M. [Ist. Trentino di Cultura, Trento (Italy)] [Ist. Trentino di Cultura, Trento (Italy); [Ist. Nazionale per la Fisica della Materia, Trento (Italy); Miotello, A. [Ist. Nazionale per la Fisica della Materia, Trento (Italy)] [Ist. Nazionale per la Fisica della Materia, Trento (Italy); [Univ. di Trento (Italy). Dipt. di Fisica

    1998-05-01

    The authors present tables of the differential, total, and transport cross sections for the elastic scattering of 500--4000 eV positrons by neutral atoms in the atomic number range Z = 1--92. The cross sections were computed by numerically solving the Dirac equation for a central electrostatic field up to a large radius where the atomic potential becomes negligible. The atomic potential used was Hartree-Fock for Z = 1--18 and Dirac-Hartree-Fock-Slater for Z = 19--92.

  2. Low-energy elastic and inelastic scattering of electrons from SO{sub 2} using the R-matrix method

    SciTech Connect

    Gupta, Monika; Baluja, K. L. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2006-04-15

    R-matrix method is used to calculate elastic differential, integral, and momentum transfer cross sections for electron-SO{sub 2} collision. The electron-impact excitation cross sections for first seven low-lying electronic excited states of SO{sub 2} molecule from the ground state of SO{sub 2} molecule have been calculated for the first time. Sixteen low-lying electronic states of SO{sub 2} molecule are included in the close coupling expansion of the wave function of the entire scattering system, which have vertical excitation energies up to 10.51 eV. Configuration-interaction (CI) wave functions are used to calculate these excitation energies. In our CI model, we keep the core 14 electrons frozen in doubly occupied molecular orbitals 1a{sub 1}, 2a{sub 1}, 3a{sub 1}, 4a{sub 1}, 1b{sub 1}, 1b{sub 2}, 2b{sub 2} and the remaining 18 electrons span the relevant active space: 5a{sub 1}, 6a{sub 1}, 7a{sub 1}, 8a{sub 1}, 9a{sub 1}, 2b{sub 1}, 3b{sub 1}, 3b{sub 2}, 4b{sub 2}, 5b{sub 2}, 6b{sub 2}, and 1a{sub 2}. Our calculated dipole moment of the ground state of SO{sub 2} at its equilibrium geometry is 0.79 a.u., which is in reasonable agreement with the corresponding experimental value 0.64 a.u. Our calculations detect one bound SO{sub 2}{sup -} state ({sup 2}B{sub 1}) at the equilibrium geometry of SO{sub 2} molecule. Both shape as well as core-excited shape resonances have been identified in the present work and are correlated with the experimental results on dissociative electron attachment study. A detailed analysis of resonances is provided. Cross sections are reported for the electron impact energy range 0-15 eV. All cross section calculations are performed in the fixed-nuclei approximation at the experimental equilibrium geometry of the ground state of SO{sub 2} molecule. We have also investigated dependence of resonances on the geometry of SO{sub 2} molecule to probe the possible pathways for dissociation of resulting negative ion upon electron attachment. We have excellent agreement of differential, elastic integral, and momentum transfer cross sections calculated in the 16-state R-matrix approximation with the available experimental results for electron-impact energy range 0-15 eV. Our resonant peaks correlate well with the peaks observed in the study of dissociative electron attachment (DEA) of electron with SO{sub 2} molecule.

  3. High order multipole three-body forces and their contribution to the elastic constants and zero point energy of the rare gas crystals

    Microsoft Academic Search

    I. J. Zucker; M. B. Doran

    1972-01-01

    High order multipole three-body forces are shown to contribute significant amounts to the theoretical values of the elastic constants of the rare gas crystals. Their effect is to make the quantity delta =(C44-C12)\\/C12 slightly more negative than the value obtained using dipole interactions only. Their effect on the harmonic zero point energy is small but of the same order as

  4. Data Network Equipment Energy Use and Savings Potential in Buildings

    SciTech Connect

    Lanzisera, Steven; Nordman, Bruce; Brown, Richard E.

    2010-06-09

    Network connectivity has become nearly ubiquitous, and the energy use of the equipment required for this connectivity is growing. Network equipment consists of devices that primarily switch and route Internet Protocol (IP) packets from a source to a destination, and this category specifically excludes edge devices like PCs, servers and other sources and sinks of IP traffic. This paper presents the results of a study of network equipment energy use and includes case studies of networks in a campus, a medium commercial building, and a typical home. The total energy use of network equipment is the product of the stock of equipment in use, the power of each device, and their usage patterns. This information was gathered from market research reports, broadband market penetration studies, field metering, and interviews with network administrators and service providers. We estimate that network equipment in the USA used 18 TWh, or about 1percent of building electricity, in 2008 and that consumption is expected to grow at roughly 6percent per year to 23 TWh in 2012; world usage in 2008 was 51 TWh. This study shows that office building network switches and residential equipment are the two largest categories of energy use consuming 40percent and 30percent of the total respectively. We estimate potential energy savings for different scenarios using forecasts of equipment stock and energy use, and savings estimates range from 20percent to 50percent based on full market penetration of efficient technologies.

  5. Design of a Protein Potential Energy Landscape by Parameter Optimization

    E-print Network

    Julian Lee; Seung-Yeon Kim; Jooyoung Lee

    2003-09-29

    We propose an automated protocol for designing the energy landscape of a protein energy function by optimizing its parameters. The parameters are optimized so that not only the global minimum energy conformation becomes native-like, but also the conformations distinct from the native structure have higher energies than those close to the native one. We successfully apply our protocol to the parameter optimization of the UNRES potential energy, using the training set of betanova, 1fsd, the 36-residue subdomain of chicken villin headpiece (PDB ID 1vii), and the 10-55 residue fragment of staphylococcal protein A (PDB ID 1bdd). The new protocol of the parameter optimization shows better performance than earlier methods where only the difference between the lowest energies of native-like and non-native conformations was adjusted without considering various degrees of native-likeness of the conformations. We also perform jackknife tests on other proteins not included in the training set and obtain promising results. The results suggest that the parameters we obtained using the training set of the four proteins are transferable to other proteins to some extent.

  6. An embedded-atom potential for the Cu Ag system

    Microsoft Academic Search

    P. L. Williams; Y. Mishin; J. C. Hamilton

    2006-01-01

    A new embedded-atom method (EAM) potential has been constructed for Ag by fitting to experimental and first-principles data. The potential accurately reproduces the lattice parameter, cohesive energy, elastic constants, phonon frequencies, thermal expansion, lattice-defect energies, as well as energies of alternate structures of Ag. Combining this potential with an existing EAM potential for Cu, a binary potential set for the

  7. Assessment of Tidal Stream Energy Potential for the United States

    NASA Astrophysics Data System (ADS)

    Haas, K. A.; Defne, Z.; Jiang, L.; Fritz, H. M.

    2010-12-01

    Tidal streams are high velocity sea currents created by periodic horizontal movement of the tides, often magnified by local topographical features such as headlands, inlets to inland lagoons, and straits. Tidal stream energy extraction is derived from the kinetic energy of the moving flow; analogous to the way a wind turbine operates in air, and as such differs from tidal barrages, which relies on providing a head of water for energy extraction. With the constantly increasing effort in promoting alternative energy, tidal streams have become promising energy sources due to their continuous, predictable and concentrated characteristics. However, the present lack of a full spatial-temporal assessment of tidal currents for the U.S. coastline down to the scale of individual devices is a barrier to the comprehensive development of tidal current energy technology. A methodology for creating a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal energy conversion technology has been developed. The tidal flows are simulated using the Regional Ocean Modeling System (ROMS). The model is calibrated and validated using observations and tidal predictions. The calibration includes adjustments to model parameters such as bottom friction coefficient, changed land/water masks, or increased grid resolutions. A systematic validation process has been developed after defining various parameters to quantify the validation results. In order to determine the total tidal stream power resource, a common method frequently proposed is to estimate it as a fraction of the total kinetic energy flux passing through a vertical section; however, this now has been shown to generally underestimate the total available resource. The total tidal energy flux includes not just the kinetic energy but also the energy flux due to the work done by the pressure force associated with the tidal motion on the water column as well, which is frequently an order of magnitude larger. The numerical model provides the time series on a sufficiently high enough spatial resolution to utilize both the currents and mean water level (MWL) to compute the total energy flux entering estuary. The time variation of the available power for a few different estuaries will be evaluated and compared to estimates based on constant flow properties.

  8. Potential environmental effects of energy conservation measures in northwest industries

    SciTech Connect

    Baechler, M C; Gygi, K F; Hendrickson, P L

    1992-01-01

    The Bonneville Power Administration (Bonneville) has identified 101 plants in the Pacific Northwest that account for 80% of the region's industrial electricity consumption. These plants offer a precise target for a conservation program. PNL determined that most of these 101 plants were represented by 11 major industries. We then reviewed 36 major conservation technologies used in these 11 industrial settings to determine their potential environmental impacts. Energy efficiency technologies designed for industrial use may result in direct or indirect environmental impacts. Effects may result from the production of the conservation measure technology, changes in the working environment due to different energy and material requirements, or changes to waste streams. Industry type, work-place conditions, worker training, and environmental conditions inside and outside the plant are all key variables that may affect environmental outcomes. To address these issues this report has three objectives: Describe potential conservation measures that Bonneville may employ in industrial programs and discuss potential primary impacts. Characterize industrial systems and processes where the measure may be employed and describe general environmental issues associated with each industry type. Review environmental permitting, licensing, and other regulatory actions required for industries and summarize the type of information available from these sources for further analysis.

  9. Intermolecular potential energy surface and thermophysical properties of ethylene oxide

    NASA Astrophysics Data System (ADS)

    Crusius, Johann-Philipp; Hellmann, Robert; Hassel, Egon; Bich, Eckard

    2014-10-01

    A six-dimensional potential energy hypersurface (PES) for two interacting rigid ethylene oxide (C2H4O) molecules was determined from high-level quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the MP2 and CCSD(T) levels of theory was utilized to determine interaction energies for 10178 configurations of two molecules. An analytical site-site potential function with 19 sites per ethylene oxide molecule was fitted to the interaction energies and fine tuned to agree with data for the second acoustic virial coefficient from accurate speed of sound measurements. The PES was validated by computing the second virial coefficient, shear viscosity, and thermal conductivity. The values of these properties are substantiated by the best experimental data as they tend to fall within the uncertainty intervals and also obey the experimental temperature functions, except for viscosity, where experimental data are insufficient. Due to the lack of reliable data, especially for the transport properties, our calculated values are currently the most accurate estimates for these properties of ethylene oxide.

  10. Potential for energy conservation in the cement industry

    SciTech Connect

    Garrett-Price, B.A.

    1985-02-01

    This report assesses the potential for energy conservation in the cement industry. Energy consumption per ton of cement decreased 20% between 1972 and 1982. During this same period, the cement industry became heavily dependent on coal and coke as its primary fuel source. Although the energy consumed per ton of cement has declined markedly in the past ten years, the industry still uses more than three and a half times the fuel that is theoretically required to produce a ton of clinker. Improving kiln thermal efficiency offers the greatest opportunity for saving fuel. Improving the efficiency of finish grinding offers the greatest potential for reducing electricity use. Technologies are currently available to the cement industry to reduce its average fuel consumption per ton by product by as much as 40% and its electricity consumption per ton by about 10%. The major impediment to adopting these technologies is the cement industry's lack of capital as a result of low or no profits in recent years.

  11. Tunnel catch from potential wells and energy detection

    E-print Network

    M. V. Karasev; E. V. Vybornyi

    2014-11-17

    We consider the one-dimensional Schr\\"{o}dinger operator in the semiclassical regime assuming that its double-well potential is the sum of a finite "physically given" well and a square shape probing well whose width or depth can be varied (tuned). We study the dynamics of initial state localized in the physical well. It is shown that if the probing well is not too close to the physical one and if its parameters are specially tuned, then the {\\it tunnel catch effect} appears, i.e. the initial state starts tunneling oscillations between the physical and probing wells. The asymptotic formula for the probability of finding the state in the probing well is obtained. We show that the observation of the tunnel catch effect can be used to determine the energy level of the initial state, and we obtain the corresponding asymptotic formula for the initial state energy. We also calculate the leading term of the tunneling splitting of energy levels in this double well potential.

  12. Gravitational potential energy of the earth - A spherical harmonic approach

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1979-01-01

    A spherical harmonic equation for the gravitational potential energy of the earth is derived for an arbitrary density distribution by conceptually bringing in mass-elements from infinity and building up the earth shell upon spherical shell. The zeroth degree term in the spherical harmonic expansion agrees with the usual expression for the energy of a radial density distribution. The second degree terms give a maximum nonhydrostatic energy in the crust and mantle of -2.77 x 10 to the 29th ergs, an order of magnitude below McKenzie's (1966) estimate. McKenzie's result stems from mathematical error. Our figure is almost identical with Kaula's (1963) estimate of the minimum shear strain energy in the mantle, a not unexpected result on the basis of the virial theorem. If the earth is assumed to be a homogeneous viscous oblate spheroid relaxing to an equilibrium shape, then a lower limit to the mantle viscosity of 1.3 x 10 to the 20th P is found by assuming that the total geothermal flux is due to viscous dissipation of energy. This number is almost six orders of magnitude below MacDonald's (1966) estimate of the viscosity and removes his objection to convection. If the nonequilibrium figure is dynamically maintained by the earth acting as a heat engine at 1% efficiency, then the viscosity is 10 to the 22nd P, a number preferred by Cathles (1975) and Peltier and Andrew (1976) as the viscosity of the mantle.

  13. Isospin dependence of {sup 6}He+p optical potential and the symmetry energy

    SciTech Connect

    Khoa, Dao T.; Hoang Sy Than [Institute for Nuclear Science and Technique, VAEC, P.O. Box 5T-160, Nghia Do, Hanoi (Viet Nam)

    2005-04-01

    A consistent folding analysis of the elastic p({sup 6}He,{sup 6}He)p scattering and charge exchange p({sup 6}He,{sup 6}Li{sup *})n reaction data measured at E{sub lab}=41.6A MeV has been performed within the coupled channels formalism. We have used the isovector coupling to link the isospin dependence of {sup 6}He+p optical potential to the cross section of p({sup 6}He,{sup 6}Li{sup *})n reaction exciting the 0{sup +} isobaric analog state (IAS) at 3.563 MeV in {sup 6}Li. Based on these results and the Hartree-Fock calculation of asymmetric nuclear matter using the same isospin-dependent effective nucleon-nucleon interaction, we were able to confirm that the most realistic value of the symmetry energy E{sub sym} is around 31 MeV. Our analysis has also shown that the measured charge exchange p({sup 6}He,{sup 6}Li{sup *})n data are quite sensitive to the halo tail of the {sup 6}He density used in the folding calculation and the IAS of {sup 6}Li is likely to have a halo structure similar to that established for the ground state of {sup 6}He.

  14. The mechanics of elastic loading and recoil in anuran jumping.

    PubMed

    Astley, Henry C; Roberts, Thomas J

    2014-12-15

    Many animals use catapult mechanisms to produce extremely rapid movements for escape or prey capture, resulting in power outputs far beyond the limits of muscle. In these catapults, muscle contraction loads elastic structures, which then recoil to release the stored energy extremely rapidly. Many arthropods employ anatomical 'catch mechanisms' to lock the joint in place during the loading period, which can then be released to allow joint motion via elastic recoil. Jumping vertebrates lack a clear anatomical catch, yet face the same requirement to load the elastic structure prior to movement. There are several potential mechanisms to allow loading of vertebrate elastic structures, including the gravitational load of the body, a variable mechanical advantage, and moments generated by the musculature of proximal joints. To test these hypothesized mechanisms, we collected simultaneous 3D kinematics via X-ray Reconstruction of Moving Morphology (XROMM) and single-foot forces during the jumps of three Rana pipiens. We calculated joint mechanical advantage, moment and power using inverse dynamics at the ankle, knee, hip and ilio-sacral joints. We found that the increasing proximal joint moments early in the jump allowed for high ankle muscle forces and elastic pre-loading, and the subsequent reduction in these moments allowed the ankle to extend using elastic recoil. Mechanical advantage also changed throughout the jump, with the muscle contracting against a poor mechanical advantage early in the jump during loading and a higher mechanical advantage late in the jump during recoil. These 'dynamic catch mechanisms' serve to resist joint motion during elastic loading, then allow it during elastic recoil, functioning as a catch mechanism based on the balance and orientation of forces throughout the limb rather than an anatomical catch. PMID:25520385

  15. Reaction dynamics of D+ H, + DH + H: Effects of potential energy surface topography and usefulness of the constant centrifugal potential

    E-print Network

    Takada, Shoji

    Reaction dynamics of D+ H, + DH + H: Effects of potential energy surface topography and usefulness possibleand enables us to investigate the effects of potential energy surface (PES) topographyon the reaction are reported for the D + H, -, DH + H reaction on the basisof the exact quantum mechanicalcalculation for J = 0

  16. Elastic and inelastic scattering of 240-MeV (6)Li ions from (40)Ca and (48)Ca and tests of a systematic optical potential 

    E-print Network

    Chen, Krishichayan X.; Lui, Y. -W; Button, J.; Youngblood, David H.

    2010-01-01

    the elastic-scattering data with the double-folding model using the density-dependent M3Y NN effective interaction and B(E2) and B(E3) values obtained for low-lying 2(+) and 3(-) states agreed with the adopted values. The results are compared with those...

  17. The torsional potential energy function of N2O4

    NASA Astrophysics Data System (ADS)

    Koput, J.; Seibert, J. W. G.; Winnewisser, B. P.

    1993-03-01

    The infrared spectrum of dinitrogen tetroxide, N2O4, has been measured in the region 200?650 cm-1 at different resolutions and temperatures. Analysis of the sequence of weak bands near 540 cm-1 involving a combination of the v6 (NO2 rocking) and v4 (torsion) modes has been performed. As a result, the shape of the potential energy function governing internal rotation about the NN bond has been determined. In the ground vibrational state, the height of the barrier at the staggered conformation is determined to be 1900 ± 200 cm-1.

  18. Taboo search by successive confinement: Surveying a potential energy surface

    NASA Astrophysics Data System (ADS)

    Chekmarev, Sergei F.

    2001-09-01

    A taboo search for minima on a potential energy surface (PES) is performed by means of confinement molecular dynamics: the molecular dynamics trajectory of the system is successively confined to various basins on the PES that have not been sampled yet. The approach is illustrated for a 13-atom Lennard-Jones cluster. It is shown that the taboo search radically accelerates the process of surveying the PES, with the probability of finding a new minimum defined by a propagating Fermi-like distribution.

  19. Potential of building-scale alternative energy to alleviate risk from the future price of energy

    Microsoft Academic Search

    David Bristow; Christopher A. Kennedy

    2010-01-01

    The energy used for building operations, the associated greenhouse gas emissions, and the uncertainties in future price of natural gas and electricity can be a cause of concern for building owners and policy makers. In this work we explore the potential of building-scale alternative energy technologies to reduce demand and emissions while also shielding building owners from the risks associated

  20. C-Phycocyanin Hydration Water Dynamics in the Presence of Trehalose: An Incoherent Elastic Neutron Scattering Study at Different Energy Resolutions

    PubMed Central

    Gabel, Frank; Bellissent-Funel, Marie-Claire

    2007-01-01

    We present a study of C-phycocyanin hydration water dynamics in the presence of trehalose by incoherent elastic neutron scattering. By combining data from two backscattering spectrometers with a 10-fold difference in energy resolution we extract a scattering law S(Q,?) from the Q-dependence of the elastic intensities without sampling the quasielastic range. The hydration water is described by two dynamically different populations—one diffusing inside a sphere and the other diffusing quasifreely—with a population ratio that depends on temperature. The scattering law derived describes the experimental data from both instruments excellently over a large temperature range (235–320 K). The effective diffusion coefficient extracted is reduced by a factor of 10–15 with respect to bulk water at corresponding temperatures. Our approach demonstrates the benefits and the efficiency of using different energy resolutions in incoherent elastic neutron scattering over a large angular range for the study of biological macromolecules and hydration water. PMID:17350998

  1. The potential effect of end-users on energy conservation in office buildings

    Microsoft Academic Search

    Seppo Junnila

    2007-01-01

    Purpose – The purpose of the study is to estimate the potential of end-user effect on energy conservation in office buildings. The study quantifies the energy conservation potential and estimates the current level of energy management in four banking organisations in the Nordic countries. Design\\/methodology\\/approach – The multiple case study employs quantitative scenario analysis for estimating the energy conservation potential

  2. Nuclear binding energy and symmetry energy of nuclear matter with modern nucleon-nucleon potentials

    SciTech Connect

    Hassaneen, Kh.S.A., E-mail: khs_94@yahoo.com [Physics Department, Faculty of Science, Sohag University, Sohag (Egypt); Abo-Elsebaa, H.M.; Sultan, E.A. [Physics Department, Faculty of Science, Sohag University, Sohag (Egypt); Mansour, H.M.M. [Physics Department, Faculty of Science, Cairo University, Giza (Egypt)

    2011-03-15

    Research Highlights: > The nuclear matter is studied within the Brueckner-Hartree-Fock (BHF) approach employing the most recent accurate nucleon-nucleon potentials. > The results come out by approximating the single particle self-consistent potential with a parabolic form. > We discuss the current status of the Coester line, i.e., density and energy of the various saturation points being strongly linearly correlated. > The nuclear symmetry energy is calculated as the difference between the binding energy of pure neutron matter and that of symmetric nuclear matter. - Abstract: The binding energy of nuclear matter at zero temperature in the Brueckner-Hartree-Fock approximation with modern nucleon-nucleon potentials is studied. Both the standard and continuous choices of single particle energies are used. These modern nucleon-nucleon potentials fit the deuteron properties and are phase shifts equivalent. Comparison with other calculations is made. In addition we present results for the symmetry energy obtained with different potentials, which is of great importance in astrophysical calculation.

  3. Energy aspects and potential energy savings of the new DASI process for milk sterilization

    SciTech Connect

    Frey, B.C. (Univ. of Maryland, College Park); Stewart, L.E.; Chandarana, D.; Wolfson, R.P.

    1981-01-01

    An experimental study was conducted to determine the difference in total processing energy required by the DASI ultra-high temperature (UHT) system and a conventional high temperature short time (HTST) fluid milk system. Data available in the literature were used to develop an energy use profile for the current US fluid milk system from processor to consumer. The energy data measured and the profile developed were used to estimate the potential energy savings resulting from the introduction of sterile milk in the US fluid milk market. Savings of energy resulting from the introduction of sterile milk were estimated to be 12 million barrels of oil annually.

  4. Ultracold collisions between two light indistinguishable diatomic molecules: Elastic and rotational energy transfer in HD+HD

    NASA Astrophysics Data System (ADS)

    Sultanov, Renat A.; Guster, Dennis; Adhikari, S. K.

    2012-05-01

    A close coupling quantum-mechanical calculation is performed for rotational energy transfer in a HD+HD collision at very low energy, down to the ultracold temperatures: T˜10-8 K. A global six-dimensional H2-H2 potential-energy surface is adopted from a previous work [Boothroyd , J. Chem. Phys.JCPSA60021-960610.1063/1.1405008 116, 666 (2002)]. State-resolved integral cross sections ?ij?i'j'(?kin) of different quantum-mechanical rotational transitions ij?i'j' in the HD molecules and corresponding state-resolved thermal rate coefficients kij?i'j'(T) have been computed. Additionally, for comparison, H2+H2 calculations for a few selected rotational transitions have also been performed. The hydrogen and deuterated hydrogen molecules are treated as rigid rotors in this work. A pronounced isotope effect is identified in the cross sections of these collisions at low and ultracold temperatures.

  5. Ultracold collisions between two light indistinguishable diatomic molecules: elastic and rotational energy transfer in HD+HD

    E-print Network

    Sultanov, Renat A; Adhikari, S K

    2011-01-01

    A close coupling quantum-mechanical calculation is performed for rotational energy transfer in a HD+HD collision at very low energy, down to the ultracold temperatures: T ~ 1.0e-8 K. A global 6-dimensional H2-H2 potential energy surface is adopted from a previous work [1]. State-resolved integral cross sections $\\sigma_{ij\\rightarrow i'j'}(\\epsilon_{kin})$ of different quantum-mechanical rotational transitions $ij\\rightarrow i'j'$ in the HD molecules and corresponding state-resolved thermal rate coefficients $k_{ij\\rightarrow i'j'}(T)$ have been computed. Additionally, for comparison, H$_2$+H$_2$ calculations for a few selected rotational transitions have also been performed. The hydrogen and deuterated hydrogen molecules are treated as rigid rotors in this work. A pronounced isotope effect is identified in the cross sections of these collisions at low and ultracold temperatures.

  6. Reflective Elastic Scattering at LHC

    E-print Network

    Sergey Troshin; Nikolay Tyurin

    2009-09-22

    We discuss effects of reflective scattering for hadron and heavy nuclei collisions at the LHC and asymptotical energies. It is shown that the reflective scattering might lead to decreasing matter density with energy beyond the LHC energies. Limiting form of energy dependence of hadron density is obtained. Unitarity upper bound for the absolute value of the real part of elastic scattering amplitude and two-particle inelastic binary reactions amplitudes in impact parameter representation is two times less than the corresponding bound for the imaginary part of the elastic scattering amplitude. The former limit restricts a possible odderon contribution.

  7. Transport mean free path tabulated for the multiple elastic scattering of electrons and positrons at energies le 20 MeV

    SciTech Connect

    Liljequist, D.; Ismail, M. (Department of Physics, University of Stockholm, Vanadisv. 9, S-113 46 Stockholm (Sweden)); Salvat, F.; Mayol, R.; Martinez, J.D. (Facultat de Fisica (ECM), Universitat de Barcelona, Societat Catalona de Fisica (IEC), Diagonal 647, 08028 Barcelona (Spain))

    1990-10-01

    The transport mean free path, or transport cross section, is tabulated for the elastic scattering of electrons and positrons in solid matter by means of a correction factor {Tc} applied to the result of a simple screened Rutherford cross section. The correction factor table is based on differential cross-section calculations using a combination of partial-wave analysis (PWA), the Wentzel--Kramers--Brillouin approximation, and the Born approximation, and covers kinetic energies from 100 eV to 20 MeV. Results at low energies are compared with PWA calculations of higher accuracy. Nuclear size effects are discussed but not explicitly included. Applications are discussed.

  8. Computer simulations of glasses: the potential energy landscape.

    PubMed

    Raza, Zamaan; Alling, Björn; Abrikosov, Igor A

    2015-07-29

    We review the current state of research on glasses, discussing the theoretical background and computational models employed to describe them. This article focuses on the use of the potential energy landscape (PEL) paradigm to account for the phenomenology of glassy systems, and the way in which it can be applied in simulations and the interpretation of their results. This article provides a broad overview of the rich phenomenology of glasses, followed by a summary of the theoretical frameworks developed to describe this phenomonology. We discuss the background of the PEL in detail, the onerous task of how to generate computer models of glasses, various methods of analysing numerical simulations, and the literature on the most commonly used model systems. Finally, we tackle the problem of how to distinguish a good glass former from a good crystal former from an analysis of the PEL. In summarising the state of the potential energy landscape picture, we develop the foundations for new theoretical methods that allow the ab initio prediction of the glass-forming ability of new materials by analysis of the PEL. PMID:26139691

  9. An Ab Initio Based Potential Energy Surface for Water

    NASA Technical Reports Server (NTRS)

    Partridge, Harry; Schwenke, David W.; Langhoff, Stephen R. (Technical Monitor)

    1996-01-01

    We report a new determination of the water potential energy surface. A high quality ab initio potential energy surface (PES) and dipole moment function of water have been computed. This PES is empirically adjusted to improve the agreement between the computed line positions and those from the HITRAN 92 data base. The adjustment is small, nonetheless including an estimate of core (oxygen 1s) electron correlation greatly improves the agreement with experiment. Of the 27,245 assigned transitions in the HITRAN 92 data base for H2(O-16), the overall root mean square (rms) deviation between the computed and observed line positions is 0.125/cm. However the deviations do not correspond to a normal distribution: 69% of the lines have errors less than 0.05/cm. Overall, the agreement between the line intensities computed in the present work and those contained in the data base is quite good, however there are a significant number of line strengths which differ greatly.

  10. He-, Ne-, and Ar-phosgene intermolecular potential energy surfaces.

    PubMed

    Munteanu, Cristian R; Henriksen, Christian; Felker, Peter M; Fernández, Berta

    2013-05-01

    Using the CCSD(T) model, we evaluated the intermolecular potential energy surfaces of the He-, Ne-, and Ar-phosgene complexes. We considered a representative number of intermolecular geometries for which we calculated the corresponding interaction energies with the augmented (He complex) and double augmented (Ne and Ar complexes) correlation-consistent polarized valence triple-? basis sets extended with a set of 3s3p2d1f1g midbond functions. These basis sets were selected after systematic basis set studies carried out at geometries close to those of the surface minima. The He-, Ne-, and Ar-phosgene surfaces were found to have absolute minima of -72.1, -140.4, and -326.6 cm(-1) at distances between the rare-gas atom and the phosgene center of mass of 3.184, 3.254, and 3.516 Å, respectively. The potentials were further used in the evaluation of rovibrational states and the rotational constants of the complexes, providing valuable results for future experimental investigations. Comparing our results to those previously available for other phosgene complexes, we suggest that the results for Cl2-phosgene should be revised. PMID:23617631

  11. Hopf solitons and elastic rods

    SciTech Connect

    Harland, Derek; Sutcliffe, Paul [Department of Mathematical Sciences, Durham University, Durham DH1 3LE (United Kingdom); Speight, Martin [School of Mathematics, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2011-03-15

    Hopf solitons in the Skyrme-Faddeev model are stringlike topological solitons classified by the integer-valued Hopf charge. In this paper we introduce an approximate description of Hopf solitons in terms of elastic rods. The general form of the elastic rod energy is derived from the field theory energy and is found to be an extension of the classical Kirchhoff rod energy. Using a minimal extension of the Kirchhoff energy, it is shown that a simple elastic rod model can reproduce many of the qualitative features of Hopf solitons in the Skyrme-Faddeev model. Features that are captured by the model include the buckling of the charge three solution, the formation of links at charges five and six, and the minimal energy trefoil knot at charge seven.

  12. The potential for effluent trading in the energy industries.

    SciTech Connect

    Veil, J. A.; Environmental Assessment

    1998-01-01

    In January 1996, the US Environmental Protection Agency (EPA) released a policy statement endorsing wastewater effluent trading in watersheds, hoping to promote additional interest in the subject. The policy describes five types of effluent trades: point source/point source, point source/nonpoint source, pretreatment, intraplant and nonpoint source/nonpoint source. This paper evaluates the feasibility of implementing these types of effluent trading for facilities in the oil and gas, electric power and coal industries. This paper finds that the potential for effluent trading in these industries is limited because trades would generally need to involve toxic pollutants, which can only be traded under a narrow range of circumstances. However, good potential exists for other types of water-related trades that do not directly involve effluents (e.g. wetlands mitigation banking and voluntary environmental projects). The potential for effluent trading in the energy industries and in other sectors would be enhanced if Congress amended the Clean Water Act (CWA) to formally authorize such trading.

  13. Crack growth in bonded elastic half planes

    NASA Technical Reports Server (NTRS)

    Goree, J. G.

    1975-01-01

    Two solutions were developed for the two dimensional problem of bonded linearly elastic half-planes. For each solution, numerical results are presented for the stress intensity factors, strain energy release rate, stresses, and displacements. The behavior predicted by the studies was investigated experimentally using polymers for the material pairs. Close agreement was found for the critical stress intensity factor at fracture for the perpendicular crack near the interface. Fracture along the interface proved to be inconclusive due to difficulties in obtaining a brittle bond. Some interesting and predictable behavior regarding the potential for the crack to cross the interface was observed and is discussed.

  14. Microscopic optical model potentials for p-nucleus scattering at intermediate energies

    NASA Astrophysics Data System (ADS)

    Hemalatha, M.; Gambhir, Y. K.; Kailas, S.; Haider, W.

    2007-03-01

    A comparative study of the microscopic optical potentials viz., semimicroscopic with extended Jeukenne-Lejeune-Mahaux interaction and microscopic Brueckner theory using Hamada-Johnston as well as Urbana V14 soft-core internucleon interactions, has been carried out. These microscopic optical potentials are compared with that of Dirac phenomenology (DP) for the polarized proton-Ca40 elastic scattering at 35 MeV and 200 MeV. These potentials have different shapes for 200 MeV below 4 fm. In particular, for the real part of the central potential, only the Dirac phenomenology and the microscopic optical potential calculated with the Hamada-Johnston interaction exhibit the well known wine-bottle-bottom shape. It is found that the calculated observables (cross section, analyzing power and spin rotation function) using these potentials having different shapes, compare well with the experiment.

  15. Calculating Potential Energy Curves with Quantum Monte Carlo

    NASA Astrophysics Data System (ADS)

    Powell, Andrew D.; Dawes, Richard

    2014-06-01

    Quantum Monte Carlo (QMC) is a computational technique that can be applied to the electronic Schrödinger equation for molecules. QMC methods such as Variational Monte Carlo (VMC) and Diffusion Monte Carlo (DMC) have demonstrated the capability of capturing large fractions of the correlation energy, thus suggesting their possible use for high-accuracy quantum chemistry calculations. QMC methods scale particularly well with respect to parallelization making them an attractive consideration in anticipation of next-generation computing architectures which will involve massive parallelization with millions of cores. Due to the statistical nature of the approach, in contrast to standard quantum chemistry methods, uncertainties (error-bars) are associated with each calculated energy. This study focuses on the cost, feasibility and practical application of calculating potential energy curves for small molecules with QMC methods. Trial wave functions were constructed with the multi-configurational self-consistent field (MCSCF) method from GAMESS-US.[1] The CASINO Monte Carlo quantum chemistry package [2] was used for all of the DMC calculations. An overview of our progress in this direction will be given. References: M. W. Schmidt et al. J. Comput. Chem. 14, 1347 (1993). R. J. Needs et al. J. Phys.: Condensed Matter 22, 023201 (2010).

  16. Single-crystal elastic properties of (Cs,Na)AlSi2O6.H2O pollucite: A zeolite with potential use for long-term storage of Cs radioisotopes

    NASA Astrophysics Data System (ADS)

    Sanchez-Valle, Carmen; Chio, Chi-Hong; Gatta, G. Diego

    2010-11-01

    The single-crystal and aggregate elastic properties of the zeolite pollucite (Cs,Na)AlSi2O6?H2O, a potential host for Cs radionucleides in geological repositories, have been determined by Brillouin scattering spectroscopy at ambient conditions. The three nonzero individual elastic constants of cubic pollucite are: C11=105.0(1.3) GPa, C44=27.0(3) GPa, and C12=25.7(6) GPa. The Voigt-Reuss-Hill average of the aggregate bulk, shear modulus, Young's modulus and Poisson's ratio are KS=52.2(1.0) GPa, G=31.5(7) GPa, E=78.6(1.0) GPa, and ? =0.248(4), respectively. The bulk modulus of pollucite is 12.7% lower than that of the all-Na isotypic mineral analcime NaAlSi2O6?H2O whereas the shear moduli G are identical within mutual uncertainties. The higher compressibility of pollucite results from the weaker Cs-O bonds compared to Na-O bonds, suggesting strong control of the nature and configuration of the extraframework content on the behavior of the structure. The elastic properties of pollucite reported here will help in the prediction of its behavior as a geological barrier and in the modeling of the short-term and long-term safety of the Cs-repositories.

  17. Relation between quark-antiquark potential and quark-antiquark free energy in hadronic matter

    E-print Network

    Zhen-Yu Shen; Xiao-Ming Xu

    2014-06-19

    We study the relation between the quark-antiquark potential and the quark-antiquark free energy in hadronic matter. While a temperature is over the critical temperature, the potential of a heavy quark and a heavy antiquark almost equals the free energy, otherwise the quark-antiquark potential is substantially larger than the quark-antiquark free energy. While a temperature is below the critical temperature, the quark-antiquark free energy can be taken as the quark-antiquark potential.

  18. Advanced Potential Energy Surfaces for Condensed Phase Simulation

    NASA Astrophysics Data System (ADS)

    Demerdash, Omar; Yap, Eng-Hui; Head-Gordon, Teresa

    2014-04-01

    Computational modeling at the atomistic and mesoscopic levels has undergone dramatic development in the past 10 years to meet the challenge of adequately accounting for the many-body nature of intermolecular interactions. At the heart of this challenge is the ability to identify the strengths and specific limitations of pairwise-additive interactions, to improve classical models to explicitly account for many-body effects, and consequently to enhance their ability to describe a wider range of reference data and build confidence in their predictive capacity. However, the corresponding computational cost of these advanced classical models increases significantly enough that statistical convergence of condensed phase observables becomes more difficult to achieve. Here we review a hierarchy of potential energy surface models used in molecular simulations for systems with many degrees of freedom that best meet the trade-off between accuracy and computational speed in order to define a sweet spot for a given scientific problem of interest.

  19. Advanced potential energy surfaces for condensed phase simulation.

    PubMed

    Demerdash, Omar; Yap, Eng-Hui; Head-Gordon, Teresa

    2014-01-01

    Computational modeling at the atomistic and mesoscopic levels has undergone dramatic development in the past 10 years to meet the challenge of adequately accounting for the many-body nature of intermolecular interactions. At the heart of this challenge is the ability to identify the strengths and specific limitations of pairwise-additive interactions, to improve classical models to explicitly account for many-body effects, and consequently to enhance their ability to describe a wider range of reference data and build confidence in their predictive capacity. However, the corresponding computational cost of these advanced classical models increases significantly enough that statistical convergence of condensed phase observables becomes more difficult to achieve. Here we review a hierarchy of potential energy surface models used in molecular simulations for systems with many degrees of freedom that best meet the trade-off between accuracy and computational speed in order to define a sweet spot for a given scientific problem of interest. PMID:24328448

  20. Osmosis, colligative properties, entropy, free energy and the chemical potential

    E-print Network

    Peter Hugo Nelson

    2014-09-13

    A diffusive model of osmosis is presented that explains currently available experimental data. It makes predictions that distinguish it from the traditional convective flow model of osmosis, some of which have already been confirmed experimentally and others have yet to be tested. It also provides a simple kinetic explanation of Raoult's law and the colligative properties of dilute aqueous solutions. The diffusive model explains that when a water molecule jumps from low to high osmolarity at equilibrium, the free energy change is zero because the work done pressurizing the water molecule is balanced by the entropy of mixing. It also explains that equal chemical potentials are required for particle exchange equilibrium in analogy with the familiar requirement of equal temperatures at thermal equilibrium.

  1. Under consideration for publication in J. Fluid Mech. 1 Available potential energy density for a

    E-print Network

    Tailleux, Remi

    with Lorenz (1955) APE, viz., APELorenz = V (pe - pe r) dV = PE - PE r, (1.1) where PE is the total potential energy of the actual state, while PE r is the total potential energy of the reference state of minimum potential energy that can be obtained from an adiabatic re-arrangement of mass (pe and pe r

  2. A General Method for Conserving Energy and Potential Enstrophy in Shallow-Water Models

    E-print Network

    Salmon, Rick

    A General Method for Conserving Energy and Potential Enstrophy in Shallow-Water Models RICK SALMON numerical models that conserve analogs of the energy and potential enstrophy; one need only discretize, in the inviscid limit, conserve energy and an arbitrary ad- ditional invariant related to the potential vorticity

  3. New Developments in Elastic Fibers

    Microsoft Academic Search

    Jinlian Hu; Jing Lu; Yong Zhu

    2008-01-01

    This paper reviews the developments of essential elastic fibers. The elastic fibers include extensible polymer fibers with low or high elasticity and reversibility which consists of the polyurethane elastic fiber, polyester?ether elastic fiber, polyester elastic fiber, olefin based elastic fiber like XLA, hard elastic fiber, bio?component fiber, and the shape memory fibers. The emphasis of the review is on the

  4. Spectroscopic constants and potential energy curves of tungsten carbide

    SciTech Connect

    Balasubramanian, K. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)

    2000-05-01

    Spectroscopic constants (R{sub e},{omega}{sub e},T{sub e},{mu}{sub e}) and potential energy curves for 40 low-lying electronic states of the diatomic tungsten carbide (WC) were obtained using the complete active space multiconfiguration self-consistent field followed by the multireference singles+doubles configuration interaction and full first- and second-order configuration interaction calculations that included up to 6.4 mil configurations. Spin-orbit effects were included through the enhanced relativistic configuration interaction method described here for 28 electronic states of WC lying below {approx}20 000 cm-1. The spin-orbit splitting of the ground state of WC was found to be very large (4394 cm-1). The ground and excited electronic states of the W atom were also computed and were found to be in good agreement with the experimental data. The nature of bonding was analyzed through the composition of orbitals, leading configurations, Mulliken populations, and dipole moments. The dissociation energy of WC was computed including spin-orbit and electron correlation effects. The recent photoelectron spectra of WC{sup -} were assigned on the basis of our computed results. (c) 2000 American Institute of Physics.

  5. Energy conservation potential of the US Department of Energy interim commercial building standards

    SciTech Connect

    Hadley, D.L.; Halverson, M.A.

    1993-12-01

    This report describes a project conducted to demonstrate the whole-building energy conservation potential achievable from full implementation of the US Department of Energy (DOE) Interim Energy Conservation Performance Standards for New Commercial and Multi-Family High Rise Residential Buildings. DOE`s development and implementation of energy performance standards for commercial buildings were established by the Energy Conservation Standards for New Buildings Act of 1976, as amended, Public Law (PL) 94-385, 42 USC 6831 et seq., hereinafter referred to as the Act. In accordance with the Act, DOE was to establish performance standards for both federal and private sector buildings ``to achieve the maximum practicable improvements in energy efficiency and use of non-depletable resources for all new buildings``.

  6. New correlation potential for the local-spin-density functional formalism I. Total energies and ionization potentials in free atoms

    Microsoft Academic Search

    L. Farkas

    1982-01-01

    Based on the recently proposed Vosko-Wilk-Nusair interpolation formulae for the correlation energy density of the spin-polarized homogeneous electron liquid, a new parametrized form for the correlation potential for the self-consistent local-spin-density calculations of atoms, molecules and solids is proposed. The total energies and first ionization potentials for a few light atoms are calculated. The influence of the improved spin-polarization dependence

  7. Elastic Scattering of {sup 7}Li+{sup 27}Al at Backward Angles in the 7-11 MeV Energy Range for Application in RBS

    SciTech Connect

    Carnelli, P. F. F.; Arazi, A.; Cardona, M. A.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J. [Laboratorio TANDAR, CNEA, Av. Gral. Paz 1499, B1650KNA, San Martin, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, Buenos Aires (Argentina); Abriola, D. [IAEA, NAPC-NDS, Vienna International Centre, PO Box 100, Vienna (Austria); Capurro, O. A.; Fimiani, L.; Grinberg, P.; Marti, G. V. [Laboratorio TANDAR, CNEA, Av. Gral. Paz 1499, B1650KNA, San Martin, Buenos Aires (Argentina); Fernandez Niello, J. O. [Laboratorio TANDAR, CNEA, Av. Gral. Paz 1499, B1650KNA, San Martin, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, Buenos Aires (Argentina); UNSAM, Campus Miguelete, B1650BWA, San Martin, Buenos Aires (Argentina)

    2010-08-04

    We have measured elastic excitation functions for the {sup 7}Li+{sup 27}Al system, in an energy range close to its Coulomb barrier (E{sub lab} = 8.4 MeV) in steps of 0.25 MeV. For this purpose, an array of eight surface-barrier detectors was used. To get an insight on the background composition (mainly {alpha} particles), a telescope-detector was used for atomic-number identification. Identical measurements for the {sup 6}Li+{sup 27}Al system are planned for the near future.

  8. Wind and Solar Energy Potential Assessment for Development of Renewables Energies Applications in Bucaramanga, Colombia

    NASA Astrophysics Data System (ADS)

    Ordóñez, G.; Osma, G.; Vergara, P.; Rey, J.

    2014-06-01

    Currently, the trend of micro-grids and small-scale renewable generation systems implementation in urban environments requires to have historical and detailed information about the energy potential resource in site. In Colombia, this information is limited and do not favor the design of these applications; for this reason, must be made detailed studies of the energy potential in their cities. In this paper is presented the wind and solar energy resource assessment for the city of Bucaramanga, based on the monitoring on four strategic points during the years 2010, 2011 and 2012. According to the analysis, is evidenced a significant solar resource throughout the year ascending on average to 1 734 kWh/m2, equivalent to 4.8 kWh/m2/day. Also, from a wind statistical study based on the Weibull probability distribution and Wind Power Density (WPD) was established the wind potential as Class 1 according to the scale of the Department of Energy of the United States (DOE), since the average speed is near 1.4 m/s. Due this, it is technically unfeasible the using of micro-turbines in the city, even so their potential for natural ventilation of building was analyzed. Finally, is presented a methodology to analyze solar harvesting by sectors in the city, according to the solar motion and shadowing caused by existing structures.

  9. Equivalence of the three empirical potential energy models for diatomic molecules

    NASA Astrophysics Data System (ADS)

    Wang, Ping-Quan; Zhang, Lie-Hui; Jia, Chun-Sheng; Liu, Jian-Yi

    2012-04-01

    It is found that the Manning-Rosen potential, Schiöberg potential and Deng-Fan potential are the same solvable empirical potential energy function for diatomic molecules. We calculate the anharmonicity ?exe and vibrational rotational coupling parameter ?e for 16 molecules by choosing the experimental values of the dissociation energy De, equilibrium bond length re and vibrational frequency ?e as inputs. The results show that the Manning-Rosen potential, Deng-Fan potential and Schiöberg potential are not better than the traditional Morse potential.

  10. The elastic scattering 7Be + p at low energies: implications on the 7Be(p, ?) 8Be S-factor

    NASA Astrophysics Data System (ADS)

    Angulo, C.; Descouvemont, P.; Cogneau, M.; Couder, M.; Gaelens, M.; Leleux, P.; Loiselet, M.; Ryckewaert, G.; Tabacaru, G.; Vanderbist, F.; Davinson, T.; Azzouz, M.; Baye, D.; Di Pietro, A.; Figuera, P.; Pizzone, R. G.; de Oliveira Santos, F.; de Séréville, N.

    2003-05-01

    The 7Be + p elastic cross section has been measured at the Centre de Recherches du Cyclotron RIB facility at Louvain-la-Neuve in the c.m. energy region from 0.3 to 0.75 MeV by bombarding a proton-rich target with a radioactive 7Be beam. The recoil protons have been detected in the angular range ?c.m. = 120.2° - 131.1° and ?c.m. = 156.6° - 170.2° using the LEDA system. From a R-matrix analysis of the cross section data, we extract the energy and the width of the 1 + resonance. The scattering lengths ?01 = 25 ± 9 fm (channel spin I = 1) and ?02 = -7 ± 3 fm (channel spin I = 2) are deduced. Implications on the low energy S-factor of the 7Be(p, ?) 8B reaction are discussed.

  11. Elastic interaction of dislocation loops and point defects

    Microsoft Academic Search

    J. Bastecká; F. Kroupa

    1964-01-01

    The elastic interaction energy of a circular dislocation loop with interstitial atoms and vacancies characterized as dilatation or relaxation centres is calculated. Further, the forces which the dislocation loops exert on point defects through elastic interaction are discussed.

  12. Molecular understanding of mutagenicity using potential energy methods

    SciTech Connect

    Broyde, S.; Shapiro, R.

    1992-07-01

    Our objective, has been to elucidate on a molecular level, at atomic resolution, the structures of DNAs modified by 2-aminofluorene and its N-acetyl derivative, 2-acetylaminofluorene (AAF). The underlying hypothesis is that DNA replicates with reduced fidelity when its normal right-handed B-structure is altered, and one result is a higher mutation rate. This change in structure may occur normally at a low incidence, for example by the formation of hairpin loops in appropriate sequences, but it may be enhanced greatly after covalent modification by a mutagenic substance. We use computational methods and have been able to incorporate the first data from NMR studies in our calculations. Computational approaches are important because x-ray and spectroscopic studies have not succeeded in producing atomic resolution views of mutagen and carcinogen-oligonucleotide adducts. The specific methods that we employ are minimized potential energy calculations using the torsion angle space molecular mechanics program DUPLEX to yield static views. Molecular dynamics simulations, with full solvent and salt, of the important static structures are carried out with the program AMBER; this yields mobile views in a medium that mimics the natural aqueous environment of the cell as well as can be done with current available computing resources.

  13. Theoretical characterization of the potential energy surface for NH + NO

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.

    1992-01-01

    The potential energy surface (PES) for NH + NO was characterized using complete active space self-consistent field (CASSCF) gradient calculations to determine the stationary point geometries and frequencies followed by CASSCF/internally contracted configuration interaction (CCI) calculations to refine the energetics. The present results are in qualitative accord with the BAC-MP4 calculations, but there are differences as large as 8 kcal/mol in the detailed energetics. Addition of NH to NO on a (2)A' surface, which correlated with N2 + OH or H + N2O products, involves barriers of 3.2 kcal/mol (trans) and 6.3 kcal/mol (cis). Experimental evidence for these barriers is found in earlier works. The (2)A' surface has no barrier to addition, but does not correlate with products. Surface crossings between the barrierless (2)A' surface and the (2)A' surface may be important. Production of N2 + OH products is predicted to occur via a planar saddle point of (2)A' symmetry. This is in accord with the preferential formation of II(A') lambda doublet levels of OH in earlier experiments. Addition of NH (1)delta to NO is found to occur on an excited state surface and is predicted to lead to N2O product as observed in earlier works.

  14. On the potential energy in an electrostatically bound two-body system

    E-print Network

    K. Wilhelm; B. N. Dwivedi

    2014-08-30

    The potential energy problem in an electrostatically bound two-body system is studied in the framework of a recently proposed impact model of the electrostatic force and in analogy to the potential energy in a gravitationally bound system. The physical processes are described that result in the variation of the potential energy as a function of the distance between the charged bodies. The energy is extracted from distributions of hypothetical interaction entities modified by the charged bodies.

  15. A method for measuring single-crystal elastic moduli using high-energy X-ray diffraction and a crystal-based finite element model

    SciTech Connect

    Efstathiou, C.; Boyce, D.E.; Park, J.-S.; Lienert, U.; Dawson, P.R.; Miller, M.P. (Cornell)

    2010-11-30

    This paper presents a method - based on high-energy synchrotron X-ray diffraction data and a crystal-based finite element simulation formulation - for understanding grain scale deformation behavior within a polycrystalline aggregate. We illustrate this method by using it to determine the single-crystal elastic moduli of {beta}21s, a body-centered cubic titanium alloy. We employed a polycrystalline sample. Using in situ loading and high-energy X-rays at the Advanced Photon Source beamline 1-ID-C, we measured components of the lattice strain tensor from four individual grains embedded within a polycrystalline specimen. We implemented an optimization routine that minimized the difference between the experiment and simulation lattice strains. Sensitivity coefficients needed in the optimization routine are generated numerically using the finite element model. The elastic moduli that we computed for the {beta}21s are C{sub 11} = 110 GPa, C{sub 12} = 74 GPa and C{sub 44} = 89 GPa. The resulting Zener anisotropic ratio is A = 5.

  16. Flapping states of an elastically anchored plate in a uniform flow with applications to energy harvesting by fluid-structure interaction

    NASA Astrophysics Data System (ADS)

    Orchini, A.; Mazzino, A.; Guerrero, J.; Festa, R.; Boragno, C.

    2013-09-01

    Linear stability analysis of an elastically anchored flat plate in a uniform flow is investigated both analytically and numerically. The analytical formulation explicitly takes into account the effect of the wake on the plate by means of Theodorsen's theory. Three different parameters non-trivially rule the observed dynamics: mass density ratio between plate and fluid, spring elastic constant, and distance between the plate center of mass and the spring anchor point on the plate. We found relationships between these parameters which rule the transition between stable equilibrium and fluttering. The shape of the resulting marginal curve has been successfully verified by high Reynolds number numerical simulations. Finally, the limiting case corresponding to a simply supported rigid rod is also analyzed and the resulting flapping instability traced back to a simple resonance condition. Our findings are of interest in applications related to energy harvesting by fluid-structure interaction, a problem that has recently attracted a great deal of attention. The main aim in that context is to identify the optimal physical/geometrical system configuration leading to large sustained motion, which is the source of energy one aims to extract.

  17. Extremely fast prey capture in pipefish is powered by elastic recoil

    Microsoft Academic Search

    Sam Van Wassenbergh; James A. Strother; Brooke E. Flammang; Lara A. Ferry-Graham; Peter Aerts

    2008-01-01

    The exceptionally high speed at which syngnathid fishes are able to rotate their snout towards prey and capture it by suction is potentially caused by a catapult mechanism in which the energy previously stored in deformed elastic elements is suddenly released. According to this hypothesis, tension is built up in tendons of the post-cranial muscles before prey capture is initiated.

  18. Energy conservation and retrofitting potential in Hellenic hotels

    Microsoft Academic Search

    M. Santamouris; C. A. Balaras; E. Dascalaki; A. Argiriou; A. Gaglia

    1996-01-01

    Energy consumption data from 158 Hellenic hotels and estimated energy savings that result from the use of practical retrofitting techniques, materials and new energy efficient systems are presented. The data were collected during an extensive energy audit of buildings that was carried out in Hellas, within the frame of a National Energy Programme sponsored by the CEC VALOREN Programme, for

  19. Computed Potential Energy Surfaces and Minimum Energy Pathways for Chemical Reactions

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.; Langhoff, S. R. (Technical Monitor)

    1994-01-01

    Computed potential energy surfaces are often required for computation of such parameters as rate constants as a function of temperature, product branching ratios, and other detailed properties. For some dynamics methods, global potential energy surfaces are required. In this case, it is necessary to obtain the energy at a complete sampling of all the possible arrangements of the nuclei, which are energetically accessible, and then a fitting function must be obtained to interpolate between the computed points. In other cases, characterization of the stationary points and the reaction pathway connecting them is sufficient. These properties may be readily obtained using analytical derivative methods. We have found that computation of the stationary points/reaction pathways using CASSCF/derivative methods, followed by use of the internally contracted CI method to obtain accurate energetics, gives usefull results for a number of chemically important systems. The talk will focus on a number of applications including global potential energy surfaces, H + O2, H + N2, O(3p) + H2, and reaction pathways for complex reactions, including reactions leading to NO and soot formation in hydrocarbon combustion.

  20. Potential scattering in atomic physics

    Microsoft Academic Search

    P. G. Burke; Robert St John

    1977-01-01

    An in-depth examination of potential field scattering of particles is presented with particular reference to elastic electron scattering by an ion or a neutral atom. Included are scattering by a short-range, Coulomb, and spin--orbit potentials, and by one-electron atoms, low energy effective-range theory, bound states and resonances, variational methods and bound principles, integral equation methods and the Born approximation, and

  1. Theory of friction: elastic coherence length and earthquake dynamics

    NASA Astrophysics Data System (ADS)

    Persson, B. N. J.; Tosatti, E.

    1999-03-01

    An elastic block on a substrate experiences a random pinning potential which breaks the lattice at the block-substrate interface into "correlated volumes" (cells of size ?) that behave elastically independent and are pinned individually. We calculate the elastic coherence length ? and discuss its relevance for sliding friction and earthquake dynamics.

  2. Resonance scattering of sound by spheroidal elastic bodies and shells

    NASA Astrophysics Data System (ADS)

    Kleshchev, A. A.

    2014-05-01

    The resonances of spheroidal elastic bodies (prolate and oblate) in the form of solid bodies and shells are determined using dynamic elasticity theory and Debye potentials. In addition to analytic solutions, results of computer calculations are presented for the angular characteristics and scattering cross sections of spheroidal elastic bodies.

  3. Aluminium interatomic potential from density functional theory calculations with improved stacking fault energy

    Microsoft Academic Search

    Xiang-Yang Liu; Furio Ercolessi; James B. Adams

    2004-01-01

    A new Al potential with improved stacking fault energy is constructed using the force-matching method. The potential is fitted to an ab initio forces database and various experimental data. By using a slightly larger cut-off, we found that the new potential gives the relaxed stacking fault energy in the experimental range without changing the excellent thermal and surface properties of

  4. New Soft-Core Potential Function for Molecular Dynamics Based Alchemical Free Energy Calculations

    E-print Network

    de Groot, Bert

    New Soft-Core Potential Function for Molecular Dynamics Based Alchemical Free Energy Calculations require the modification of the classical nonbonded potential energy terms by applying soft-core potential functions to avoid singularity points. In this work, we propose a novel formulation for a soft

  5. A comparative study of the He-Sb(111) interaction potential from close-coupling calculations and helium atom scattering experiments

    NASA Astrophysics Data System (ADS)

    Kraus, Patrick; Mayrhofer-Reinhartshuber, Michael; Gösweiner, Christian; Apolloner, Florian; Miret-Artés, Salvador; Ernst, Wolfgang E.

    2014-12-01

    The exact elastic close-coupling formalism is used to compare the performance of several interaction potentials suggested in literature for describing the measured elastic diffraction peak intensities in helium scattering experiments. The coupling parameters have been analytically calculated for the corrugated Morse potential on a hexagonal surface structure and adapted for usage with similar interaction potentials. The potentials used have been fitted to previously known bound state energies complemented by two additional levels which are found by improving energy resolution. It is established that the shifted Morse potential reproduces the experimental He-Sb(111) bound state more closely than the other considered potential shapes. The performance of several interaction potentials in describing the elastic scattering intensities is presented and discussed. Morse and Morse-related potentials provide the best compromise for the description of elastic scattering intensities. The different effects of the potential shape were determined by comparing the calculated scattering intensities.

  6. Calculation of all cubic single-crystal elastic constants from single atomistic simulation: Hydrogen effect and elastic constants of nickel

    Microsoft Academic Search

    M. Wen; A. Barnoush; K. Yokogawa

    2011-01-01

    Previous direct methods for evaluating all elastic constants require separate molecular dynamics runs with different loads. Here, we show that only a single run is enough to evaluate all elastic constants of cubic crystals. We evaluate the temperature dependence of all elastic constants of Ni to check the reliability of the embedded-atom method potential developed by Angelo et al. and

  7. An embedded-atom potential for the Cu–Ag system

    Microsoft Academic Search

    P L Williams; Y Mishin; J C Hamilton

    2006-01-01

    A new embedded-atom method (EAM) potential has been constructed for Ag by fitting to experimental and first-principles data. The potential accurately reproduces the lattice parameter, cohesive energy, elastic constants, phonon frequencies, thermal expansion, lattice-defect energies, as well as energies of alternate structures of Ag. Combining this potential with an existing EAM potential for Cu, a binary potential set for the

  8. Dynamics of oxygen in the YBa sub 2 Cu sub 3 O sub 7 minus x basal planes by elastic-energy-loss measurements

    SciTech Connect

    Cannelli, G. (Universita di Perugia, Dipartimento di Fisica, I-06100 Perugia (Italy)); Cantelli, R. (II Universita di Roma, Dipartimento di Fisica, Via E. Carnevale, I-00173 Roma (Italy)); Cordero, F. (Consiglio Nazionale delle Richerche, Istituto di Acustica O. M. Corbino,'' via Cassia 1216, I-00189 Roma (Italy)); Ferretti, M. (Universita di Genova, Istituto di Chimica Fisica, I-16132 Genova (Italy)); Verdini, L. (Universita di Perugia, Dipartimento di Fisica, I-06100 Perugia (Italy))

    1990-11-01

    We report elastic-energy-dissipation measurements in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} from 50 to 300 K at frequencies between 0.48 and 6.3 kHz. It is shown unambiguously that the two peaks around {Tc} are thermally activated with activation energies of 0.16 and 0.19 eV. When oxygen is reduced to about 6.5 atoms per formula unit, the higher-temperature process nearly disappears, while the other one increases. The peaks are interpreted in terms of jumps of the O atoms in the Cu-O basal planes, and two mechanisms are proposed and discussed: short jumps between the off-center positions in the chains and jumps between O(4) and O(5) positions of isolated atoms in hypothetical oxygen-depleted islands of the orthorhombic basal planes.

  9. Thermochemistry, bond energies, and internal rotor potentials of dimethyl tetraoxide.

    PubMed

    da Silva, Gabriel; Bozzelli, Joseph W

    2007-11-29

    Thermochemical properties of dimethyl tetraoxide (CH(3)OOOOCH(3)), the dimer of the methylperoxy radical, are studied using ab initio and density functional theory methods. Methylperoxy radicals are known to be important intermediates in the tropospheric ozone cycle, and the self-reaction of methylperoxy radicals, which is thought to proceed via dimethyl tetraoxide, leads to significant chain radical termination in this process. Dimethyl tetraoxide has five internal rotors, three of them unique; the potential energy profiles are calculated for these rotors, as well as for those in the CH(3)OO, CH(3)OOO, and CH(3)OOOO radicals. The dimethyl tetraoxide internal rotor profiles show barriers to rotation of 2-8 kcal mol(-1). Using B3LYP/6-31(d) geometries, frequencies, internal rotor potentials, and moments of inertia, we determine entropy and heat capacity values for dimethyl tetraoxide and its radicals. Isodesmic work reactions with the G3B3 and CBS-APNO methods are used; we calculate this enthalpy as -9.8 kcal mol(-1). Bond dissociation energies (BDEs) are calculated for all C-O and O-O bonds in dimethyl tetraoxide, again with the G3B3 and CBS-APNO theoretical methods, and we suggest the following BDEs: 46.0 kcal mol(-1) for CH(3)-OOOOCH(3), 20.0 kcal mol(-1) for CH(3)O-OOOCH(3), and 13.9 kcal mol(-1) for CH(3)OO-OOCH(3). From the BDE calculations and the isodesmic enthalpy of formation for dimethyl tetraoxide, we suggest enthalpies of 2.1, 5.8, and 1.4 kcal mol(-1) for the CH(3)OO, CH(3)OOO, and CH(3)OOOO radicals, respectively. We evaluate the suitability of 10 different density functional theory (DFT) methods for calculating thermochemical properties of dimethyl tetraoxide and its radicals with the 6-31G(d) and 6-311++G(3df,3pd) basis sets, using a variety of work reaction schemes. Overall, the best-performed DFT methods of those tested were TPSSh, BMK, and B1B95. Significant improvements in accuracy were made by moving from atomization to isodesmic work reactions, with most DFT methods yielding errors of less than 2 kcal mol(-1) with the 6-311++G(3df,3pd) basis set for isodesmic calculations on the dimethyl tetraoxide enthalpy. These isodesmic calculations were basis set consistent, with a considerable reduction in error found by using the 6-311++G(3df,3pd) basis set over the 6-31G(d) basis set. This was not the case, however, for atomization and bond dissociation work reactions, where the two basis sets returned similar results. Improved group additivity terms for the O-O-O moiety (O/O2 central atom group) are also determined. PMID:17983209

  10. Land Transport Demand Analysis and Energy Saving Potentials in Thailand

    Microsoft Academic Search

    Jakapong Pongthanaisawan; Chumnong Sorapipatana; Bundit Limmeechokchai

    Transportation is one of the major economic sectors in energy consumption. For Thailand, this sector has been the largest energy consuming sector. It accounted for about 38% of the total energy consumption and about 80% of this sector was used in the road transport in 2004. During 2000 - 2004, the energy consumption in the transport sector in Thailand increased

  11. Market potential of renewable energy powered desalination systems in Greece

    Microsoft Academic Search

    D. Voivontas; K. Yannopoulos; K. Rados; A. Zervos; D. Assimacopoulos

    1999-01-01

    The present work analyzes water management strategies based on advanced desalination schemes powered by renewable energy sources. The framework for developing a decision procedure, which monitors water shortage problems and identifies the availability of renewable energy resources to power desalination plants, is presented. Cost of alternative solutions, taking into account energy cost or profits by energy selling to grid, is

  12. Potential Ambient Energy-Harvesting Sources and Techniques

    ERIC Educational Resources Information Center

    Yildiz, Faruk

    2009-01-01

    Ambient energy harvesting is also known as energy scavenging or power harvesting, and it is the process where energy is obtained from the environment. A variety of techniques are available for energy scavenging, including solar and wind powers, ocean waves, piezoelectricity, thermoelectricity, and physical motions. For example, some systems…

  13. By-products: oil sorbents as a potential energy source.

    PubMed

    Karakasi, Olga K; Moutsatsou, Angeliki

    2013-04-01

    The present study investigated the utilization of an industrial by-product, lignite fly ash, in oil pollution treatment, with the further potential profit of energy production. The properties of lignite fly ash, such as fine particle size, porosity, hydrophobic character, combined with the properties, such as high porosity and low specific gravity, of an agricultural by-product, namely sawdust, resulted in an effective oil-sorbent material. The materials were mixed either in the dry state or in aqueous solution. The oil sorption behaviour of the fly ash-sawdust mixtures was investigated in both marine and dry environments. Mixtures containing fly ash and 15-25% w/w sawdust performed better than each material alone when added to oil spills in a marine environment, as they formed a cohesive semi-solid phase, adsorbing almost no water, floating on the water surface and allowing total oil removal. For the clean-up of an oil spill 0.5 mm thick with surface area 1000 m(2), 225-255 kg of lignite fly ash can be utilized with the addition of 15-25% w/w sawdust. Fly ash-sawdust mixtures have also proved efficient for oil spill clean-up on land, since their oil sorption capacity in dry conditions was at least 0.6-1.4 g oil g(-1) mixture. The higher calorific value of the resultant oil-fly ash-sawdust mixtures increased up to that of bituminous coal and oil and exceeded that of lignite, thereby encouraging their utilization as alternative fuels especially in the cement industry, suggesting that the remaining ash can contribute in clinker production. PMID:23179513

  14. Networks of triboelectric nanogenerators for harvesting water wave energy: a potential approach toward blue energy.

    PubMed

    Chen, Jun; Yang, Jin; Li, Zhaoling; Fan, Xing; Zi, Yunlong; Jing, Qingshen; Guo, Hengyu; Wen, Zhen; Pradel, Ken C; Niu, Simiao; Wang, Zhong Lin

    2015-03-24

    With 70% of the earth's surface covered with water, wave energy is abundant and has the potential to be one of the most environmentally benign forms of electric energy. However, owing to lack of effective technology, water wave energy harvesting is almost unexplored as an energy source. Here, we report a network design made of triboelectric nanogenerators (TENGs) for large-scale harvesting of kinetic water energy. Relying on surface charging effect between the conventional polymers and very thin layer of metal as electrodes for each TENG, the TENG networks (TENG-NW) that naturally float on the water surface convert the slow, random, and high-force oscillatory wave energy into electricity. On the basis of the measured output of a single TENG, the TENG-NW is expected to give an average power output of 1.15 MW from 1 km(2) surface area. Given the compelling features, such as being lightweight, extremely cost-effective, environmentally friendly, easily implemented, and capable of floating on the water surface, the TENG-NW renders an innovative and effective approach toward large-scale blue energy harvesting from the ocean. PMID:25719956

  15. Improved expressions for the Schiöberg potential energy models for diatomic molecules

    NASA Astrophysics Data System (ADS)

    Wang, Ping-Quan; Liu, Jian-Yi; Zhang, Lie-Hui; Cao, Si-Yi; Jia, Chun-Sheng

    2012-08-01

    By employing the dissociation energy and the equilibrium bond length for a diatomic molecule as explicit parameters, we generate improved expressions for both versions of the Schiöberg potential energy function. Both versions of the Schiöberg potential function are the Rosen-Morse potential function and Manning-Rosen potential functions. By choosing the experimental values of the dissociation energy, equilibrium bond length and equilibrium harmonic vibrational frequency as inputs, we calculate the average deviations of the energies calculated with the potential model from the experimental data for five diatomic molecules, and find that no one of six three-parameter empirical potential energy functions is superior to the other potentials in fitting experimental data for all molecules examined.

  16. Lighting energy savings potential of split-pane electrochromic windows controlled for

    E-print Network

    LBNL-6152E Lighting energy savings potential of split- pane electrochromic windows controlled Berkeley National Laboratory G. Ward Anyhere Software Windows and Envelope Materials Group Building potential of split-pane electrochromic windows controlled for daylighting with visual comfort L

  17. Interaction potential for silicon carbide: A molecular dynamics study of elastic constants and vibrational density of states for crystalline and amorphous silicon carbide

    Microsoft Academic Search

    Priya Vashishta; Rajiv K. Kalia; Aiichiro Nakano; José Pedro Rino

    2007-01-01

    An effective interatomic interaction potential for SiC is proposed. The potential consists of two-body and three-body covalent interactions. The two-body potential includes steric repulsions due to atomic sizes, Coulomb interactions resulting from charge transfer between atoms, charge-induced dipole-interactions due to the electronic polarizability of ions, and induced dipole-dipole (van der Waals) interactions. The covalent characters of the Si-C-Si and C-Si-C

  18. Interaction potential for silicon carbide: A molecular dynamics study of elastic constants and vibrational density of states for crystalline and amorphous silicon carbide

    Microsoft Academic Search

    Priya Vashishta; Rajiv K. Kalia; Aiichiro Nakano; Jose´ Pedro Rino

    2007-01-01

    An effective interatomic interaction potential for SiC is proposed. The potential consists of two-body and three-body covalent interactions. The two-body potential includes steric repulsions due to atomic sizes, Coulomb interactions resulting from charge transfer between atoms, charge-induced dipole-interactions due to the electronic polarizability of ions, and induced dipole-dipole (van der Waals) interactions. The covalent characters of the Si–C–Si and C–Si–C

  19. Nuclear rainbow in elastic scattering of {sup 9}Be nuclei

    SciTech Connect

    Glukhov, Yu. A., E-mail: gloukhov@inbox.ru; Ogloblin, A. A.; Artemov, K. P.; Rudakov, V. P. [Russian Research Center Kurchatov Institute (Russian Federation)

    2010-01-15

    A systematic investigation of the elastic scattering of the {sup 9}Be nucleus, which is among themost loosely bound stable nuclei was performed.Differential cross sections for elastic {sup 9}Be + {sup 16}O scattering were measured at a c.m. energy of 47.5 MeV (beam of 132-MeV {sup 16}O nuclei). Available data at different energy values and data for neighboring nuclei were included in our analysis. As a result, the very fact of rainbow scattering was reliably established for the first time in systems involving {sup 9}Be. In addition, the analysis in question made it possible to identify Airy minima and to determine unambiguously the nucleus-nucleus potential with a high probability.

  20. Molecular dynamic calculation of elastic constants of silicon

    Microsoft Academic Search

    Mark D. Kluge; John R. Ray; Aneesur Rahman

    1986-01-01

    Stillinger and Weber have introduced a model potential to study the solid and liquid forms of silicon. This potential has been used in a number of computer simulation studies of silicon. We have calculated the elastic constants of silicon using the Stillinger–Weber potential at three different temperatures T=888, 1164, and 1477 K. The adiabatic elastic constants are calculated using fluctuation

  1. A potential enstrophy and energy conserving scheme for the shallow water equations

    NASA Technical Reports Server (NTRS)

    Arakawa, A.; Lamb, V. R.

    1981-01-01

    To improve the simulation of nonlinear aspects of the flow over steep topography, a potential enstrophy and energy conserving scheme for the shallow water equations is derived. It is pointed out that a family of schemes can conserve total energy for general flow and potential enstrophy for flow with no mass flux divergence. The newly derived scheme is a unique member of this family, that conserves both potential enstrophy and energy for general flow. Comparison by means of numerical experiment with a scheme that conserves (potential) enstrophy for purely horizontal nondivergent flow demonstrated the considerable superiority of the newly derived potential enstrophy and energy conserving scheme, not only in suppressing a spurious energy cascade but also in determining the overall flow regime. The potential enstrophy and energy conserving scheme for a spherical grid is also presented.

  2. Rovibrational energy transfer in the He-C3 collision: potential energy surface and bound states.

    PubMed

    Denis-Alpizar, Otoniel; Stoecklin, Thierry; Halvick, Philippe

    2014-02-28

    We present a four-dimensional potential energy surface (PES) for the collision of C3 with He. Ab initio calculations were carried out at the coupled-cluster level with single and double excitations and a perturbative treatment of triple excitations, using a quadruple-zeta basis set and mid-bond functions. The global minimum of the potential energy is found to be -26.9 cm(-1) and corresponds to an almost T-shaped structure of the van der Waals complex along with a slightly bent configuration of C3. This PES is used to determine the rovibrational energy levels of the He-C3 complex using the rigid monomer approximation (RMA) and the recently developed atom-rigid bender approach at the Close Coupling level (RB-CC). The calculated dissociation energies are -9.56 cm(-1) and -9.73 cm(-1), respectively at the RMA and RB-CC levels. This is the first theoretical prediction of the bound levels of the He-C3 complex with the bending motion. PMID:24588178

  3. Ground state potential energy curve and dissociation energy of MgH.

    PubMed

    Shayesteh, Alireza; Henderson, Robert D E; Le Roy, Robert J; Bernath, Peter F

    2007-12-13

    New high-resolution visible emission spectra of the MgH molecule have been recorded with high signal-to-noise ratios using a Fourier transform spectrometer. Many bands of the A 2Pi-->X 2Sigma+ and B' 2Sigma+-->X 2Sigma+ electronic transitions of 24MgH were analyzed; the new data span the v' = 0-3 levels of the A 2Pi and B'2Sigma+ excited states and the v''=0-11 levels of the X 2Sigma+ ground electronic state. The vibration-rotation energy levels of the perturbed A 2Pi and B' 2Sigma+ states were fitted as individual term values, while those of the X 2Sigma+ ground state were fitted using the direct-potential-fit approach. A new analytic potential energy function that imposes the theoretically correct attractive potential at long-range, and a radial Hamiltonian that includes the spin-rotation interaction were employed, and a significantly improved value for the ground state dissociation energy of MgH was obtained. The v''=11 level of the X 2Sigma+ ground electronic state was found to be the highest bound vibrational level of 24MgH, lying only about 13 cm(-1) below the dissociation asymptote. The equilibrium dissociation energy for the X 2Sigma+ ground state of 24MgH has been determined to be De=11104.7+/-0.5 cm(-1) (1.37681+/-0.00006 eV), whereas the zero-point energy (v''=0) is 739.11+/-0.01 cm(-1). The zero-point dissociation energy is therefore D0=10365.6+/-0.5 cm(-1) (1.28517+/-0.00006 eV). The uncertainty in the new experimental dissociation energy of MgH is more than 2 orders of magnitude smaller than that for the best value available in the literature. MgH is now the only hydride molecule other than H2 itself for which all bound vibrational levels of the ground electronic state are observed experimentally and for which the dissociation energy is determined with subwavenumber accuracy. PMID:18020428

  4. Dependence of the energy of vanishing flow on different components of the nuclear potential

    NASA Astrophysics Data System (ADS)

    Kaur, Mandeep; Kaur, Varinderjit; Kumar, Suneel

    2013-11-01

    The contribution of various components of potential towards balance energy is analyzed for the reactions of 2658Fe+2658Fe, 2858Ni+2858Ni, 3686Kr+4193Nb, and 79197Au+79197Au using an isospin-dependent quantum molecular dynamics (IQMD) model. We show that the balance energy changes with the addition of various components of potentials. Our calculations for the considered energy range clearly demonstrate the dominance of the Coulomb potential and momentum-dependent interactions over the other potentials for the lighter colliding systems. However, the contribution of the symmetry potential also becomes significant while handling heavier nuclei.

  5. Energy Consumption and Conservation Potential at a Georgia Textile Plant

    E-print Network

    Gurta, M. E.; Brown, M. L.

    prosperity. With energy constituting a major component of variable operating costs, an analysis of energy consumption at a typical integrated mill was formulated. Because the process includes knitting, bleaching, dyeing, and compaction and the knitting area...

  6. A model for a constrained, finitely deforming, elastic solid with rotation gradient dependent strain energy, and its specialization to von Kármán plates and beams

    NASA Astrophysics Data System (ADS)

    Srinivasa, A. R.; Reddy, J. N.

    2013-03-01

    The aim of this paper is to develop the governing equations for a fully constrained finitely deforming hyperelastic Cosserat continuum where the directors are constrained to rotate with the body rotation. This is the generalization of small deformation couple stress theories and would be useful for developing mathematical models for an elastic material with embedded stiff short fibers or inclusions (e.g., materials with carbon nanotubes or nematic elastomers, cellular materials with oriented hard phases, open cell foams, and other similar materials), that account for certain longer range interactions. The theory is developed as a limiting case of a regular Cosserat elastic material where the directors are allowed to rotate freely by considering the case of a high "rotational mismatch energy". The theory is developed using the formalism of Lagrangian mechanics, with the static case being based on Castigliano's first theorem. By considering the stretch U and the rotation R as additional independent variables and using the polar decomposition theorem as an additional constraint equation, we obtain the governing and as well as the boundary conditions for finite deformations. The resulting equations are further specialized for plane strain and axisymmetric finite deformations, deformations of beams and plates with small strain and moderate rotation, and for small deformation theories. We also show that the boundary conditions for this theory involve "surface tension" like terms due to the higher gradients in the strain energy function. For beams and plates, the rotational gradient dependent strain energy does not require additional variables (unlike Cosserat theories) and additional differential equations; nor do they raise the order of the differential equations, thus allowing us to include a material length scale dependent response at no extra "computational cost" even for finite deformation beam/plate theories

  7. Wind energy potential mapping in Karnataka, India, using GIS

    Microsoft Academic Search

    T. V. Ramachandra; B. V. Shruthi

    2005-01-01

    Increasing negative effects of fossil fuel combustion on the environment in addition to limited stock have forced many countries to explore and change to environmentally friendly alternatives that are renewable to sustain the increasing energy demand. Changing to renewable sources and implementation of effective conservation measures would ensure sustainability. Currently, wind energy is one of the fastest developing renewable energy

  8. FORTRAN 4 programs for the extraction of potential well parameters from the energy dependence of total elastic scattering cross sections

    NASA Technical Reports Server (NTRS)

    Labudde, R. A.

    1972-01-01

    An attempt has been made to keep the programs as subroutine oriented as possible. Usually only the main programs are directly concerned with the problem of total cross sections. In particular the subroutines POLFIT, BILINR, GASS59/MAXLIK, SYMOR, MATIN, STUDNT, DNTERP, DIFTAB, FORDIF, EPSALG, REGFAL and ADSIMP are completely general, and are concerned only with the problems of numerical analysis and statistics. Each subroutine is independently documented.

  9. Positron interactions with water–total elastic, total inelastic, and elastic differential cross section measurements

    SciTech Connect

    Tattersall, Wade [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Chiari, Luca [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia)] [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Machacek, J. R.; Anderson, Emma; Sullivan, James P. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)] [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); White, Ron D. [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia)] [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Brunger, M. J. [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia) [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Buckman, Stephen J. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Garcia, Gustavo [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain)] [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain); Blanco, Francisco [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)] [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2014-01-28

    Utilising a high-resolution, trap-based positron beam, we have measured both elastic and inelastic scattering of positrons from water vapour. The measurements comprise differential elastic, total elastic, and total inelastic (not including positronium formation) absolute cross sections. The energy range investigated is from 1 eV to 60 eV. Comparison with theory is made with both R-Matrix and distorted wave calculations, and with our own application of the Independent Atom Model for positron interactions.

  10. Mechanics of Elastic Solids

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    After conducting the associated activity, students are introduced to the material behavior of elastic solids. Engineering stress and strain are defined and their importance in designing devices and systems is explained. How engineers measure, calculate and interpret properties of elastic materials is addressed. Students calculate stress, strain and modulus of elasticity, and learn about the typical engineering stress-strain diagram (graph) of an elastic material.

  11. The Technical and Economic Potential for Electricity Energy Efficiency in a Semiconductor Manufacturing Plant 

    E-print Network

    Lee, A. H. W.; Golden, J. W.; Zarnikau, J. W.

    1997-01-01

    . This paper presents the potential for energy efficiency improvements at a semiconductor manufacturing plant from various energy efficiency measures such as high efficiency motors, adjustable speed drive motors, high efficiency HVAC, and high efficiency...

  12. The potential and challenges of monitoring-supported energy efficiency improvement strategies in existing buildings

    E-print Network

    Schub, M.; Mahdavi, A.; Simonis, H.; Menzel, K.; Browne, D.

    2012-01-01

    The ongoing EU-supported CAMPUS 21 explores the energy efficiency potential of integrated security, control, and building management software. The main objective of the project is to compare the energy and indoor-environmental performance...

  13. The potential and challenges of monitoring-supported energy efficiency improvement strategies in existing buildings 

    E-print Network

    Schub, M.; Mahdavi, A.; Simonis, H.; Menzel, K.; Browne, D.

    2012-01-01

    The ongoing EU-supported CAMPUS 21 explores the energy efficiency potential of integrated security, control, and building management software. The main objective of the project is to compare the energy and indoor-environmental performance...

  14. Analysis of the Potential Energy Savings for 14 Office Buildings with VAV Systems 

    E-print Network

    Claridge, D. E.; Liu, J.; Baltazar, J. C.

    2010-01-01

    At the beginning of an existing building commissioning (EBCx)/energy retrofit project, some form of screening is usually applied to determine whether there is sufficient potential for savings to justify a formal EBCx assessment/energy audit...

  15. The optimal elastic flagellum

    E-print Network

    Saverio E. Spagnolie; Eric Lauga

    2009-09-26

    Motile eukaryotic cells propel themselves in viscous fluids by passing waves of bending deformation down their flagella. An infinitely long flagellum achieves a hydrodynamically optimal low-Reynolds number locomotion when the angle between its local tangent and the swimming direction remains constant along its length. Optimal flagella therefore adopt the shape of a helix in three dimensions (smooth) and that of a sawtooth in two dimensions (non-smooth). Physically, biological organisms (or engineered micro-swimmers) must expend internal energy in order to produce the waves of deformation responsible for the motion. Here we propose a physically-motivated derivation of the optimal flagellum shape. We determine analytically and numerically the shape of the flagellar wave which leads to the fastest swimming while minimizing an appropriately-defined energetic expenditure. Our novel approach is to define an energy which includes not only the work against the surrounding fluid, but also (1) the energy stored elastically in the bending of the flagellum, (2) the energy stored elastically in the internal sliding of the polymeric filaments which are responsible for the generation of the bending waves (microtubules), and (3) the viscous dissipation due to the presence of an internal fluid. This approach regularizes the optimal sawtooth shape for two-dimensional deformation at the expense of a small loss in hydrodynamic efficiency. The optimal waveforms of finite-size flagella are shown to depend upon a competition between rotational motions and bending costs, and we observe a surprising bias towards half-integer wave-numbers. Their final hydrodynamic efficiencies are above 6%, significantly larger than those of swimming cells, therefore indicating available room for further biological tuning.

  16. First-principle study of structural, elastic and electronic properties of Th monopnictides

    NASA Astrophysics Data System (ADS)

    Amari, S.; Méçabih, S.; Abbar, B.; Bouhafs, B.

    2014-11-01

    In this work, first principles calculation of structural, electronic and elastic properties of thorium monopnictides ThX (N, P, As, Sb and Bi) are presented. The calculations are performed by a developed full-potential augmented plane wave plus local orbitals (FP-L/APW+lo) method within the density functional theory (DFT). The exchange and correlation potential energies are treated according to the generalized gradient approximation (GGA) using the Perdew, Burke, Ernzerhof (PBE) parameterization, and the local density approximation (LDA). We have calculated the lattice parameters, bulk modulii and the first pressure derivatives of the bulk modulii. The elastic properties of the studied compounds are only investigated in the most stable calculated phase. We have obtained Young's modulus, shear modulus, Poisson's ratio, anisotropy factor and Kleinman parameter by the aid of the calculated elastic constants. We discuss the total and partial densities of states and charge densities.

  17. Student reasoning about electrostatic and gravitational potential energy: An exploratory study with interdisciplinary consequences

    NASA Astrophysics Data System (ADS)

    Lindsey, Beth A.

    2014-06-01

    This paper describes an investigation into student reasoning about potential energy in the context of introductory electrostatics. Similar incorrect reasoning patterns emerged both in written questions administered after relevant instruction and in one-on-one interviews. These reasoning patterns are also prevalent in responses to questions posed about gravitational potential energy in the context of universal gravitation in introductory mechanics. This finding is relevant for interdisciplinary research, because many courses in multiple disciplines first introduce the concept of electric potential energy in analogy to gravitational potential energy. The results suggest that in introductory courses students do not gain an understanding of potential energy that is sufficiently robust to apply in more advanced physics courses or in disciplines other than physics, in which students must frequently reason with energy in the context of interactions between atoms and molecules.

  18. GEOTHERMAL ENERGY: AN OVERVIEW ON RESOURCES AND POTENTIAL

    Microsoft Academic Search

    Ruggero Bertani

    Electricity is produced by geothermal in 24 countries, five of which obtain 15-22% of their national electricity production from geothermal energy. Direct application of geo- thermal energy (for heating, bathing etc.) has been reported by 72 countries. By the end of 2004, the worldwide use of geothermal energy was 57 TWh\\/yr of electricity and 76 TWh\\/yr for direct use. Ten

  19. Consequences of Converting Graded to Action Potentials upon Neural Information Coding and Energy Efficiency

    PubMed Central

    Sengupta, Biswa; Laughlin, Simon Barry; Niven, Jeremy Edward

    2014-01-01

    Information is encoded in neural circuits using both graded and action potentials, converting between them within single neurons and successive processing layers. This conversion is accompanied by information loss and a drop in energy efficiency. We investigate the biophysical causes of this loss of information and efficiency by comparing spiking neuron models, containing stochastic voltage-gated Na+ and K+ channels, with generator potential and graded potential models lacking voltage-gated Na+ channels. We identify three causes of information loss in the generator potential that are the by-product of action potential generation: (1) the voltage-gated Na+ channels necessary for action potential generation increase intrinsic noise and (2) introduce non-linearities, and (3) the finite duration of the action potential creates a ‘footprint’ in the generator potential that obscures incoming signals. These three processes reduce information rates by ?50% in generator potentials, to ?3 times that of spike trains. Both generator potentials and graded potentials consume almost an order of magnitude less energy per second than spike trains. Because of the lower information rates of generator potentials they are substantially less energy efficient than graded potentials. However, both are an order of magnitude more efficient than spike trains due to the higher energy costs and low information content of spikes, emphasizing that there is a two-fold cost of converting analogue to digital; information loss and cost inflation. PMID:24465197

  20. Attraction of mesoscale objects on the surface of a thin elastic film supported on a liquid.

    PubMed

    Chakrabarti, Aditi; Chaudhury, Manoj K

    2015-02-17

    We study the interaction of two parallel rigid cylinders on the surface of a thin elastic film supported on a pool of liquid. The excess energy of the surface due to the curvature of the stretched film induces attraction of the cylinders that can be quantified by the variation of their gravitational potential energies as they descend into the liquid while still floating on the film. Although the experimental results follow the trend predicted from the balance of the gravitational and elastic energies of the system, they are somewhat underestimated. The origin of this discrepancy is the hysteresis of adhesion between the cylinder and the elastic film that does not allow the conversion of the total available energy into gravitational potential energy, as some part of it is recovered in stretching the film behind the cylinders while they approach each other. A modification of the model accounting for the effects of adhesion hysteresis improves the agreement between theoretical and experimental results. The contribution of the adhesion hysteresis can be reduced considerably by introducing a thin hydrogel layer atop the elastic film that enhances the range of attraction of the cylinders (as well as rigid spheres) in a dramatic way. Morphological instabilities in the gel project corrugated paths to the motion of small spheres, thus leading to a large numbers of particles to aggregate along their defects. These observations suggest that a thin hydrogel layer supported on a deformable elastic film affords an effective model system to study elasticity and defects mediated interaction of particles on its surface. PMID:25069091