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1

Optical-potential model calculation of electron-hydrogen elastic scattering at intermediate and high energies  

SciTech Connect

Elastic scattering of electrons from hydrogen in the energy range 30--400eV is studied. The calculations are performed using an optical potential toimprove the close-coupling approximation. The calculation at 30 eV employs an18-state basis set emphasizing long-range pseudostates, while at 100 and 400 eVan 11-state basis containing more compact pseudostates is found to be moresuitable. Differential elastic cross sections are presented and compared withexperiments. Integrated elastic and total inelastic cross sections are alsoreported and compared with values estimated semiempirically.

Callaway, J.; Unnikrishnan, K.

1989-08-01

2

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

NASA Astrophysics Data System (ADS)

High precision angular distribution data of (?,?) elastic scattering are presented for the nuclei 89Y, 92Mo, 106Cd, 112Sn, and 144Sm 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 ?. 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.

Mohr, P.; Kiss, G. G.; Fülöp, Zs.; Galaviz, D.; Gyürky, Gy.; Somorjai, E.

2013-11-01

3

Energy-harvesting potential of multiple elastic structures in tandem arrangement  

NASA Astrophysics Data System (ADS)

Vortex-induced flapping vibrations of elastic structures attached with piezoelectric materials, i.e., ``piezo-leaves'', have recently been explored for its potential application in wind energy harvesting (e.g., Li, Yuan, and Lipson, J. Appl. Phys., 2011). In this work, we explore the possibility of enhancing the structural vibration and energy harvesting performance of the generator by putting the leaves in tandem arrangement and within close range of hydrodynamic interaction. A two-dimensional model is developed, where two or more elastic plates are mounted in a cross flow. In the case of two plates, the numerical simulation shows that at a particular distance, the vibration of the downstream plate is greatly increased, and so is the energy level of the entire system. For multiple plates, we observed both synchronized and apparently chaotic vibration modes. The characteristics of the vortex interaction, plate deformation, and energetics will be presented for those coupling modes.

Yin, Bo; Luo, Haoxiang

2011-11-01

4

Elastic Energy Driven Polymerization  

PubMed Central

We present a molecular system where polymerization is controlled externally by tuning the elastic energy of the monomers. The elastic energy, provided by a DNA molecular spring, destabilizes the monomer state through a process analogous to domain swapping. This energy can be large (of ?10 kT) and thus drive polymerization at relatively low monomer concentrations. The monomer-dimer equilibrium provides a measurement of the elastic energy of the monomer, which in this construction appears limited by kink formation in the DNA molecular spring, in accord with previous theoretical and experimental investigations of the elasticity of sharply bent DNA.

Wang, Andrew; Zocchi, Giovanni

2009-01-01

5

Complementary optical-potential analysis of {alpha}-particle elastic scattering and induced reactions at low energies  

SciTech Connect

A previously derived semi-microscopic analysis based on the Double Folding Model, for {alpha}-particle elastic scattering on A{approx}100 nuclei at energies below 32 MeV, is extended to medium mass A{approx}50-120 nuclei and energies from {approx}13 to 50 MeV. The energy-dependent phenomenological imaginary part for this semi-microscopic optical model potential was obtained including the dispersive correction to the microscopic real potential, and used within a concurrent phenomenological analysis of the same data basis. A regional parameter set for low-energy {alpha}-particles entirely based on elastic scattering data analysis was also obtained for nuclei within the above mentioned mass and energy ranges. Then, an ultimate assessment of ({alpha},{gamma}), ({alpha},n), and ({alpha},p) reaction cross sections considered target nuclei from {sup 45}Sc to {sup 118}Sn and incident energies below {approx}12 MeV. The former diffuseness of the real part of optical potential as well as the surface imaginary potential depth have been found to be responsible for the actual difficulties in the description of these data, and modified in order to obtain an optical potential which describes equally well both the low-energy elastic scattering and induced reaction data for {alpha}-particles.

Avrigeanu, M. ['Horia Hulubei' National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, 76900 Bucharest (Romania)], E-mail: mavrig@ifin.nipne.ro; Obreja, A.C.; Roman, F.L.; Avrigeanu, V. ['Horia Hulubei' National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, 76900 Bucharest (Romania); Oertzen, W. von [Freie Universitaet Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin (Germany); Hahn-Meitner-Institut, Glienicker Strasse 100, 14109 Berlin (Germany)

2009-07-15

6

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

PubMed Central

We propose a novel method of calculation of free energy for coarse grained models of proteins by combining our newly developed multibody potentials with entropies computed from elastic network models of proteins. Multi-body potentials have been of much interest recently because they take into account three dimensional interactions related to residue packing and capture the cooperativity of these interactions in protein structures. Combining four-body non-sequential, four-body sequential and pairwise short range potentials with optimized weights for each term, our coarse-grained potential improved recognition of native structure among misfolded decoys, outperforming all other contact potentials for CASP8 decoy sets and performance comparable to the fully atomic empirical DFIRE potentials. By combing statistical contact potentials with entropies from elastic network models of the same structures we can compute free energy changes and improve coarse-grained modeling of protein structure and dynamics. The consideration of protein flexibility and dynamics should improve protein structure prediction and refinement of computational models. This work is the first to combine coarse-grained multibody potentials with an entropic model that takes into account contributions of the entire structure, investigating native-like decoy selection.

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

2011-01-01

7

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

NASA Astrophysics Data System (ADS)

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(?=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(?=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 (?=10,j=0) and (?=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.

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

8

Phenomenology of elastic energy loss  

SciTech Connect

The unexpectedly strong suppression of high p{sub T} heavy quarks in heavy-ion collisions has given rise to the idea that partons propagating through a medium in addition to energy loss by induced radiation also undergo substantial energy loss due to elastic collisions. However, the precise magnitude of this elastic energy-loss component is highly controversial. Although for a parton inside a medium it is surprisingly difficult to define the difference between elastic and radiative processes rigorously, the main phenomenological difference is in the dependence of energy loss on in-medium path length: in a constant medium radiative energy loss is expected to grow quadratically with path length, elastic energy loss linearly. In this article, we investigate a class of energy-loss models with such a linear path-length dependence and demonstrate that they are incompatible with measured data on hard hadronic back-to-back correlations where a substantial variation of path length is probed. This indicates that any elastic energy-loss component has to be small.

Renk, Thorsten [Department of Physics, P. O. Box 35, University of Jyvaeskylae, FI-40014 (Finland); Helsinki Institute of Physics, P. O. Box 64, University of Helsinki, FI-00014 (Finland)

2007-12-15

9

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

PubMed

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 the elastic constants as a function of density and temperature, the generalized stacking fault energy and the low-index surface energies. PMID:21817375

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

2009-01-29

10

Potential Energy\\/Kinetic Energy  

Microsoft Academic Search

Objectives:\\u000aStudents will:\\u000a1. use modeling to calculate the spring constant of a super ball\\u000a2. use modeling to predict the elastic bounce (spring constant of other balls)\\u000aThis will help the student understand the elastic potential energy, kinetic energy, restoring force of a ball bounced at an angle, period, frequency of springs in simple harmonic motion Modeling will allow

David Rogers

2004-01-01

11

On the conditions of potentiality in finite elasticity and hypo-elasticity  

Microsoft Academic Search

Thermodynamic approaches to finite elasticity are almost generally accepted. Nevertheless, there is still a lack of proof for the necessity of potential strain-stress relations in generally defined elasticity and hypo-elasticity. This situation has resulted in ambiguous applications of the general concept of elasticity to the description of irreversible phenomena in viscoelastic solids and liquids. This paper makes a brief review

Arkady I. Leonov

2000-01-01

12

Elastic bars with cohesive energy  

NASA Astrophysics Data System (ADS)

Most quasi-static variational models of fracture are based on the splitting of the energy functional into the sum of two terms: bulk, depending on the displacement gradient, and surface, depending on the displacement discontinuities. In this paper we consider the simplest one-dimensional problem of this type, a bar stretched by a given axial displacement, and systematically compare two alternative interpretations of the surface energy term. In the first interpretation ( elastic model), the surface energy is viewed as a cohesive energy which is stored and can be recovered. In the second ( inelastic model), it is irreversibly lost. We show that by assuming an evolution scheme based on local minimization and by varying the convexity-concavity properties of the surface energy the elastic model can reproduce a broad class of macroscopic material responses which have been traditionally treated as unrelated. These responses are associated with monotone loading and range from brittle fracture to rate independent plasticity. However, a realistic description for both loading and unloading is achieved only within the inelastic model.

Piero, Gianpietro Del; Truskinovsky, Lev

2009-07-01

13

Love Numbers And Elastic Energy Of Deformation For Venus  

Microsoft Academic Search

Love numbers of second order of Venus are calculated with resolving fundamental differential equations of elastic body according\\u000a to the parameters of the density and the elasticity of material by means of the PVM94-01 Venus model. Meanwhile, the elastic\\u000a energy of deformation of second order due to the tidal perturbation of the Sun and that due to rotational centrifugal potential

Y. F. Xia; N. Y. Xiao

2000-01-01

14

Quasi-elastic scattering and fusion with a modified Woods-Saxon potential  

SciTech Connect

The elastic and large-angle quasi-elastic scattering reactions were studied with the same nucleus-nucleus potential proposed for describing fusion reactions. The elastic scattering angle distributions of some reactions are reasonably well reproduced by the proposed Woods-Saxon potential with fixed parameters at energies much higher than the Coulomb barrier. With an empirical barrier distribution based on the modified Woods-Saxon potential and taking into account the influence of nucleon transfer, the calculated quasi-elastic scattering cross sections of a series of reactions are in good agreement with the experimental data.

Wang Ning; Scheid, Werner [Department of Physics, Guangxi Normal University, Guilin 541004 (China); Institut fuer Theoretische Physik der Universitaet, D-35392 Giessen (Germany)

2008-07-15

15

Extended optical model analyses of elastic scattering and fusion cross section data for the {sup 12}C+{sup 208}Pb system at near-Coulomb-barrier energies by using a folding potential  

SciTech Connect

Simultaneous {chi}{sup 2} analyses are performed for elastic scattering and fusion cross section data for the {sup 12}C+{sup 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}{sup 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 {sup 16}O.

So, W. Y. [Department of Physics, University of Texas, Austin, Texas 78712 (United States); Department of Radiological Science, Catholic University of Pusan, Pusan 609-757 (Korea, Republic of); Udagawa, T. [Department of Physics, University of Texas, Austin, Texas 78712 (United States); Hong, S. W.; Kim, B. T. [Department of Physics and Institute of Basic Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2008-02-15

16

High energy elastic and diffractive scattering  

SciTech Connect

The developments in high energy pp and p{bar p} elastic scattering in the last 30 years are summarized. The Regge pole model and the geometrical models are reviewed and their agreement with experimental data discussed. The experimental method for measuring the total cross section and the ratio of the real to the imaginary part of the forward elastic scattering amplitude, p, is described. The asymptotic behavior of the total cross section at high energy is discussed in the light of the new results on p{bar p} elastic scattering at {radical}s=1.8 TeV. Predictions from geometrical models and Regge phenomenology are compared with experimental data. The 2-gluon model of the Pomeron by Low and Nussinov is discussed. Future measurements on elastic pp and p{bar p} elastic scattering are discussed.

Shukla, S.

1992-08-01

17

Potential Energy  

NSDL National Science Digital Library

Part of a comprehensive physics tutorial for high school students, this page describes potential energy conceptually and mathematically, provides examples enhanced by illustrations, and problems for practice with drop down boxes for your answers and feedback. In the left navigation bar, click on Kinetic Energy to get parallel information on kinetic energy.

2010-01-01

18

Indirect readout: detection of optimized subsequences and calculation of relative binding affinities using different DNA elastic potentials  

Microsoft Academic Search

Essential biological processes require that proteins bind to a set of specific DNA sites with tuned relative affinities. We focus on the indirect readout mechanism and discuss its theoretical description in relation to the present understanding of DNA elasticity on the rigid base pair level. Combining existing parametrizations of elastic potentials for DNA, we derive elastic free energies directly related

Nils B. Becker; Lars Wolff; Ralf Everaers

2006-01-01

19

Elastic electron scattering from molecular potentials  

Microsoft Academic Search

Fink and co-workers have reported a molecular electron density function for the nitrogen molecule which was derived from an experimental differential electron scattering cross section. The transformation of the data was accomplished by assuming that the first Born approximation could be used to describe the scattering process. This procedure is analyzed by considering a higher order treatment of the elastic

D. A. Kohl; M. M. Arvedson

1980-01-01

20

Structural, elastic and thermal properties of cementite from Modified Embedded Atom Method (MEAM) potential  

NASA Astrophysics Data System (ADS)

Structural, elastic and thermal properties of cementite were studied using a newly developed MEAM potential for the Fe-C alloy system. The single element potential of C correctly predicts graphite and diamond as the two stable structures. Parameters for the Fe-C alloy potential were constructed based on the structural and elastic properties of elements in the L12 reference structure, calculated from ab-initio simulations. Parameters were further adjusted to reproduce structural properties of cementite and the interstitial energies for Fe correctly. Pair potential parameters were optimized using a method combining Latin hypercube sampling of the N-dimensional parameter space and multi-objective optimization. Elastic constants, surface formation energies, melting temperature and specific heat of cementite were calculated using the potential. The values computed from the Fe-C alloy MEAM potential are in good agreement with DFT calculations and experiments.

Liyanage, Laalitha; Houze, Jeff; Kim, Seong-Gon; Tschopp, Mark; Kim, Sungho; Baskes, Mike; Horstemeyer, Mark

2012-02-01

21

Elastic energy of polyhedral bilayer vesicles  

PubMed Central

In recent experiments the spontaneous formation of hollow bilayer vesicles with polyhedral symmetry has been observed. On the basis of the experimental phenomenology it was suggested 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.

Haselwandter, Christoph A.; Phillips, Rob

2011-01-01

22

Elastic potentials and the structure of inelastic constitutive laws  

Microsoft Academic Search

Abseact. The existence of a work potential. governing materlal response when elastic behav~or occurs. is shown to prov~de a concise framework for the structure of inelastic constitutive laws. The discussion includes the identification of differential invariants In conjugate stress and straln variables, an examination and reformulat~on of postulates leading to \\

R. HILLt; J. R. Rice

1973-01-01

23

Elastically bounded flapping wing for energy harvesting  

NASA Astrophysics Data System (ADS)

In this Letter, we present and discuss an energy harvesting device, based on a wing elastically bounded to a fixed support. Large amplitude and periodic oscillations can be induced when this system is subject to wind, if a few parameters are carefully set. A linear stability analysis as well as two-dimensional numerical simulations confirms the existence of instability regions in the parameter space. In order to harvest energy by using this system, different methods are considered. Preliminary results obtained by an electromagnetic coupling are presented.

Boragno, C.; Festa, R.; Mazzino, A.

2012-06-01

24

Study of 9Be + 12C elastic scattering at energies near the Coulomb barrier  

NASA Astrophysics Data System (ADS)

In this work, angular distribution measurements for the elastic channel were performed for the 9Be + 12C reaction at the energies E=13.0, 14.5, 17.3, 19.0 and 21.0 MeV, near the Coulomb barrier. The data have been analyzed in the framework of the double folding São Paulo potential. The experimental elastic scattering angular distributions were well described by the optical potential at forward angles for all measured energies. However, for the three highest energies, an enhancement was observed for intermediate and backward angles. This can be explained by the elastic transfer mechanism.

Oliveira, R. A. N.; Carlin, N.; Neto, R. Liguori; de Moura, M. M.; Munhoz, M. G.; del Santo, M. G.; Souza, F. A.; Szanto, E. M.; Szanto de Toledo, A.; Suaide, A. A. P.

2011-04-01

25

Invariant potential for elastic pion-nucleus scattering  

Microsoft Academic Search

From the Wick-Dyson expansion of the exact propagator of a pion in the presence of a nucleus, an invariant potential for crossing symmetric elastic pion-nucleus scattering is obtained in terms of a series of pion-nucleon diagrams. The Chew-Low theory is used to develop a model in which the most important class of diagrams is effectively summed. Included in this model

J. Barry Cammarata; Manoj K. Banerjee

1976-01-01

26

Elastic energy flux by flexible polymers in fluid turbulence.  

PubMed

We present a study of the energy transfer in the bulk of a turbulent flow with dilute long-chain polymer additives. Based on prior work by Tabor and de Gennes [Europhys. Lett. 2, 519 (1986); Physica (Amsterdam) 140A, 9 (1986)], we propose a theory on the energy flux into the elastic degrees of freedom of the polymer chains. This elastic energy flux, which increases as the length scale decreases, gradually reduces the energy transferred to smaller scales through turbulence cascade and hence suppresses small scale fluctuations. The balance of the elastic energy flux and the turbulence energy cascade gives an elastic length scale, which describes the effect of polymer elasticity on turbulence in the inertial range. Predictions of this new "energy flux balance theory" agree excellently with our experimental results. PMID:23889409

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

2013-07-09

27

Global Dirac optical potentials for elastic proton scattering from heavy nuclei  

SciTech Connect

We present global Dirac optical model fits to elastic proton scattering data from heavy nuclear targets at energies between 65 and 1040 MeV. Such optical potentials provide critical input for a wide variety of nuclear reactions. The energy and mass number dependence of the parameters in the Lorentz four-vector and scalar potentials of Dirac phenomenology are given. The characteristic features of the potentials are discussed and the predictive power of the global approach presented here is tested for both interpolation and extrapolation.

Hama, S.; Clark, B.C. (Department of Physics, The Ohio State University, Columbus, Ohio 43210 (USA)); Cooper, E.D. (Department of Physics, McGill University, Montreal, Quebec, Canada H3A2T8 (Canada) Department of Physics, Surrey University, Guildford GU25XH, Surrey, (England)); Sherif, H.S. (Department of Physics, University of Alberta, Alberta, Canada T6G2J1 (Canada)); Mercer, R.L. (IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (USA))

1990-06-01

28

Dark energy as an elastic strain fluid  

NASA Astrophysics Data System (ADS)

The origin of the accelerated expansion of the Universe is still unclear and new physics is needed on cosmological scales. We propose and test a novel interpretation of dark energy as originated by an elastic strain due to a cosmic defect in an otherwise Euclidean space-time. The strain modifies the expansion history of the universe. This new effective contribution tracks radiation at early times and mimics a cosmological constant at late times. The theory is tested against observations, from nucleosynthesis to the cosmic microwave background and formation and evolution of large-scale structure to supernovae. Data are very well reproduced with Lamé parameters of the order of 10-52 m-2.

Radicella, N.; Sereno, M.; Tartaglia, A.

2013-02-01

29

Estimating disaggregated price elasticities in industrial energy demand  

SciTech Connect

Econometric energy models are used to evaluate past policy experiences, assess the impact of future policies and forecast energy demand. This paper estimates an industrial energy demand model for the province of Ontario using a linear-logit specification for fuel type equations which are embedded in an aggregate energy demand equation. Short-term, long-term, own- and cross-price elasticities are estimated for electricity, natural gas, oil and coal. Own- and cross-price elasticities are disaggregated to show that overall price elasticities and the energy-constant price elasticities when aggregate energy use is held unchanged. These disaggregations suggest that a substantial part of energy conservation comes from the higher aggregate price of energy and not from interfuel substitution. 13 refs., 2 tabs.

Elkhafif, M.A.T. (Ontario Ministry of Energy, Toronto (Canada))

1992-01-01

30

Measurements of radiated elastic wave energy from dynamic tensile cracks  

NASA Astrophysics Data System (ADS)

To determine the conditions under which elastic waves are radiated from crack sources, dynamic tensile cracks were propagated in glass samples in the double cantilever beam geometry. This geometry allows simple calculation of the strain energy release rate G at initiation from measured parameters of crack length, applied crack opening force, and crack opening displacement. Partial control over the strain energy state in the sample at fracture initiation, and hence G at initiation, was achieved by varying the geometry of the notch tip from which the fracture emanates. Elastic wave displacements were monitored with a broadband capacitance transducer with a pointlike probe. A single component of elastic wave displacement (parallel to the crack plane and perpendicular to the crack propagation direction) was measured. Two fracture configurations were investigated: (1) "primary fracture" in glass plates of dimension 305×102 ×12.7 mm and (2) "secondary fracture" in previously fractured glass plates of the same dimensions, bonded intermittently along the fracture plane. Primary fracture experiments afforded a means of investigating elastic wave radiation from mode I cracks in a highly brittle material, such that the strain energy released by the fracture is partitioned into fracture surface energy of the newly formed crack walls and radiated elastic wave energy; negligible energy is expended in ductile or frictional processes. Secondary fracture experiments afforded a means of investigating elastic wave radiation in the case of varying fracture surface energy along the crack path. For primary fracture, measurable elastic waves from the macrofracture were generated in 31% of the 16 dynamic fracture events monitored. The condition for radiation of measurable waves from these fractures appears to be a local abrupt change in the fracture path direction, such as occurs when the fracture intersects a surface flaw. For the five events with measurable elastic waves, the ratio of radiated elastic wave energy in the measured component to the fracture surface energy of the macrocrack was 0.0001-0.001. For secondary fracture, 100% of the 13 events monitored showed measurable elastic waves. The ratio of radiated elastic wave energy in the measured component to fracture surface energy was 0.001-0.01, or 10 times greater than for primary fracture. The observed value of G at crack initiation for both primary and secondary fracture ranged from 3 to 48 J m-2. When the time window for radiated elastic wave energy calculation was restricted to a few microseconds after the first arrival, a weak correlation of radiated elastic wave energy with initiation G value was observed for secondary fractures.

Boler, Frances M.

1990-03-01

31

Non-monotonic potential description of alpha-Zr refractive elastic scattering  

NASA Astrophysics Data System (ADS)

Experimental differential cross sections of ? elastic scattering by 90Zr in the 15.0-141.7 MeV range of the bombarding energies have been analysed within the framework of an optical model using non-monotonic (NM) potentials. These potentials are generated from the energy-density functional theory using a realistic two-nucleon potential coupled with an appropriate consideration of the Pauli principle. The NM nature of the real part of the potential seems to be gradually diminishing at energies beyond 118.0 MeV. The Airy structure of the nuclear rainbow scattering data in the energy range of 79.5-141.7 MeV is for the first time well accounted for by the shallow NM potential. Two potential families, which are located in the real part, bear a linear variation of a volume integral in the energy range 25.0-141.7 MeV with a threshold anomaly at the lower energies. The potential contains an interior repulsive part that, with energy, shifts towards the surface and gradually weakens until it is almost lost in the nuclear surface. The requirement of a deep attractive real part of the nuclear potential seems to be generally non-stringent for describing the nuclear rainbow oscillations. Some discrete ambiguities in the potentials seem to persist even when the ‘exponential falloff’ in the angular distribution following the ‘rainbow angle’ is well reproduced in this investigation using the NM real part of the optical potentials.

Hossain, S.; Billah, Masum; Azad, M. M. B.; Parvin, Farzana; Abdullah, M. N. A.; Hasan, K. M.; Uddin, M. A.; Tariq, A. S. B.; Basak, A. K.; Reichstein, I.; Malik, F. B.

2013-10-01

32

Energy of the elastic loading of anharmonic solids  

NASA Astrophysics Data System (ADS)

This paper reports on the results of measurements of changes in the temperature of a solid under the adiabatic elastic loading (thermoelastic effect), the coefficient of thermal expansion, and the Young's modulus of a rigid-chain vitrified polymer, namely, polyimide. It has been found that there are differences in the sign and magnitude of the changes in the energy of thermal origin in samples and the work of the external force. The energy of the thermoelastic effect has been explained in terms of the influence exerted by the anharmonic expansion of a solid, with the separation of the quasi-static potential and dynamic components of the thermal energy of the solid. The loading with an external force causes a redistribution of the thermal energy. A change in the temperature of the solid corresponds to a change in the dynamic component. An energy analysis of the adiabatically loaded anharmonic oscillator has confirmed the conclusion regarding the mechanism of energy transfer and revealed that, under loading, there is a redistribution of the kinetic and potential components of the internal energy of the oscillator.

Slutsker, A. I.; Polikarpov, Yu. I.; Karov, D. D.; Gofman, I. V.

2013-03-01

33

Measurement of the elastic energy of sharply bent ds DNA  

NASA Astrophysics Data System (ADS)

We present measurements of the elastic energy of short (30 bp), sharply bent, ds DNA molecules. The measurements are obtained by two independent methods: one is based on the monomer-dimer equilibrium of an appropriate configuration where the elastic energy stored in the bent strands drives dimer formation; the other is based on melting curves analysis. We find that, for example, the elastic energy of a sharply bent 30 bp double stranded DNA molecule with a nick at the center does not exceed 10 kBT.

Qu, Hao; Wang, Yong; Tseng, Chiao-Yu; Zocchi, Giovanni

2010-03-01

34

Open shell effects in a microscopic optical potential for elastic scattering of 6(8)He  

NASA Astrophysics Data System (ADS)

Elastic scattering observables (differential cross section and analyzing power) are calculated for the reaction 6He(p,p)6He at projectile energies starting at 71 MeV/nucleon. The optical potential needed to describe the reaction is based on a microscopic Watson first-order folding potential, which explicitly takes into account that the two neutrons outside the 4He core occupy an open p shell. The folding of the single-particle harmonic oscillator density matrix with the nucleon-nucleon t matrix leads for this case to new terms not present in traditional folding optical potentials for closed shell nuclei. The effect of those new terms on the elastic scattering observables is investigated. Furthermore, we study the influence of an exponential tail of the p-shell wave functions on the scattering observables, as well as the sensitivity of the observables to variations of matter and charge radius. Finally, elastic scattering observables for the reaction 8He(p,p)8He are presented at selected projectile energies.

Orazbayev, A.; Elster, Ch.; Weppner, S. P.

2013-09-01

35

Fusion and Quasi-elastic scattering around the Coulomb barrier: determination of inter-nucleus potential  

SciTech Connect

We invert experimental data for heavy-ion fusion cross sections at energies well below the Coulomb barrier in order to directly determine the internucleus potential between the colliding nuclei. In contrast to the previous applications of the inversion formula, we explicitly take into account the effect of channel couplings on fusion reactions, by assuming that fusion cross sections at deep subbarrier energies are governed by the lowest barrier in the barrier distribution. The surface region of the internuclear potential is determined from quasi-elastic scattering at deep subbarrier energies, while the inner part is determined with the WKB formula. We apply this procedure to the {sup 16}O+{sup 144}Sm and {sup 16}O+{sup 208}Pb reactions, and find that the inverted internucleus potential are much thicker than phenomenological potentials.

Hagino, K. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

2009-05-04

36

Optical potential analysis of proton elastic scattering from 12C based on the ?-particle model  

NASA Astrophysics Data System (ADS)

Based on an ?-particle model of 12C, an optical potential for intermediate-energy proton- 12C scattering is presented in the framework of the KMT theory. The parameterized proton- 4He amplitude, the required basic input for constructing the optical potential, is obtained by fitting the proton- 4He scattering data. The differential cross-sections and analyzing powers of the proton- 12C elastic scattering at incident energies ranging from 0.2 to 1.0GeV have been calculated by using the obtained optical potential. The main features of the measured angular distributions of the cross-section and the analyzing power can be satisfactorily described. The proton- 12C total cross-sections have also been calculated, and the results are in good agreement with the experimental data at energies below 0.6GeV but underestimate the data about 6% at higher energies.

Yang, Yong-Xu; Zhou, Jin-Li; Li, Qing-Run

2007-04-01

37

Proton-{sup 3}He elastic scattering at low energies  

SciTech Connect

We present new accurate measurements of the differential cross section {sigma}({theta}) and the proton analyzing power A{sub y} for proton-{sup 3}He elastic scattering at various energies. A supersonic gas-jet target has been employed to obtain these low-energy cross-section measurements. The {sigma}({theta}) distributions have been measured at E{sub p}=0.99, 1.59, 2.24, 3.11, and 4.02 MeV. Full angular distributions of A{sub y} have been measured at E{sub p}=1.60, 2.25, 3.13, and 4.05 MeV. This set of high-precision data is compared to four-body variational calculations employing realistic nucleon-nucleon (NN) and three-nucleon (3N) interactions. For the unpolarized cross section, the agreement between the theoretical calculation and data is good when a 3N potential is used. The comparison between the calculated and measured proton analyzing powers reveals discrepancies of approximately 50% at the maximum of each distribution. This is analogous to the existing 'A{sub y} puzzle' known for the past 20 years in nucleon-deuteron elastic scattering.

Fisher, B. M.; Brune, C. R.; Karwowski, H. J.; Leonard, D. S.; Ludwig, E. J.; Black, T. C.; Viviani, M.; Kievsky, A.; Rosati, S. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3255, USA and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308 (United States) and Department of Physics and Physical Oceanography, University of North Carolina at Wilmington, Wilmington, North Carolina 28403 (United States); Istituto Nazionale di Fisica Nucleare, Sezione di Pisa (Italy); and Department of Physics, University of Pisa, I-56100 Pisa (Italy)

2006-09-15

38

Do we understand elastic scattering up to LHC energies?  

NASA Astrophysics Data System (ADS)

The measurements of high energy 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 ?tot(s), the total elastic cross section ?el(s), the ratio of the real to imaginary parts of the forward amplitude ?(s) and the differential cross section d? (s,t)/dt.

Soffer, Jacques

2013-04-01

39

Elastic Hadron Scattering on Li Isotopes at Intermediate Energies  

SciTech Connect

The elastic scattering of hadrons (protons, charged pions, and positively charged kaons) on {sup 6,7,8}Li nuclei is analyzed on the basis of Glauber-Sitenko diffraction theory. A few nuclear-wave-function versions found within two- and three-particle potential cluster models are used in the calculations. It is shown that the application of these wave functions in diffraction theory makes it possible to describe adequately the experimental differential cross sections and analyzing powers in hadron scattering at intermediate energies. In this study, particular attention is given to a comparison of the scattering of different particles on the same target nucleus, as well as to a comparison of scattering of particles of the same sort on different target nuclei.

Zhusupov, M.A.; Imambekov, O. [Institute of Experimental and Theoretical Physics, Kazakh State University, ul. Timiryazeva 46, Almaty, 480121 (Kazakhstan); Ibraeva, E.T. [Institute of Nuclear Physics, National Nuclear Center of the Republic of Kazakhstan, Almaty, 480082 (Kazakhstan)

2005-01-01

40

Polyconvex potentials, invertible deformations, and thermodynamically consistent formulation of the nonlinear elasticity equations  

NASA Astrophysics Data System (ADS)

It is shown that the nonstationary finite-deformation thermoelasticity equations in Lagrangian and Eulerian coordinates can be written in a thermodynamically consistent Godunov canonical form satisfying the Friedrichs hyperbolicity conditions, provided that the elastic potential is a convex function of entropy and of the minors of the elastic deformation Jacobian matrix. In other words, the elastic potential is assumed to be polyconvex in the sense of Ball. It is well known that Ball’s approach to proving the existence and invertibility of stationary elastic deformations assumes that the elastic potential essentially depends on the second-order minors of the Jacobian matrix (i.e., on the cofactor matrix). However, elastic potentials constructed as approximations of rheological laws for actual materials generally do not satisfy this requirement. Instead, they may depend, for example, only on the first-order minors (i.e., the matrix elements) and on the Jacobian determinant. A method for constructing and regularizing polyconvex elastic potentials is proposed that does not require an explicit dependence on the cofactor matrix. It guarantees that the elastic deformations are quasiisometries and preserves the Lame constants of the elastic material.

Garanzha, V. A.

2010-09-01

41

Investigation of ?-nuclear potential families from elastic scattering experiments  

NASA Astrophysics Data System (ADS)

In this work we present the continuation of the reported analysis [1] of the experimentally measured angular distributions of the reaction 106Cd(?, ?)106Cd at several different energies around the Coulomb barrier. The difficulties that arise in the study of 106Cd-?-nuclear potential and the so called Family Problem are addressed.

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

2012-02-01

42

Energy dependence of the elastic diffraction slopes  

Microsoft Academic Search

We have redetermined and compiled the diffraction-slope parameter B for pi+\\/-p, K+\\/-p, pp, and pp, fitting the forward-elastic data from the literature to 1n dsigma\\/dt = A + Bt +(Ct2). We then fit this compilation, together with the total-cross-section data, to a Regge model with a pomeron of slope ~1\\/2 interfering with exchange-degenerate meson trajectories. Thus we account for the

T. Lasinski; R. Levi Setti; B. Schwarzschild; P. Ukleja

1971-01-01

43

The elastic energy of sharply bent nicked DNA  

NASA Astrophysics Data System (ADS)

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.

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

2010-04-01

44

Low-energy elastic electron interactions with pyrimidine  

SciTech Connect

We present results of measurements and calculations of elastic electron scattering from pyrimidine in the energy range 3-50 eV. Absolute differential and integral elastic cross sections have been measured using a crossed electron-molecule beam spectrometer and the relative flow technique. The measured cross sections are compared with results of calculations using the well-known Schwinger variational technique and an independent-atom model. Agreement between the measured differential cross sections and the results of the Schwinger calculations is good at lower energies but less satisfactory at higher energies where inelastic channels that should be open are kept closed in the calculations.

Palihawadana, Prasanga; Sullivan, James; Buckman, Stephen [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Brunger, Michael [Centre for Antimatter-Matter Studies, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Institute of Mathematical Sciences, University of Malaya, 50603, Kuala Lumpur (Malaysia); Winstead, Carl; McKoy, Vincent [A A Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States); Garcia, Gustavo [Consejo Superior de Investigaciones Cientificas, Serrano 113-bis, ES-28006 Madrid (Spain); Blanco, F. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, ES-28040 Madrid (Spain)

2011-12-15

45

Elastic scattering and total reaction cross sections with low-energy light radioactive ion beams.  

NASA Astrophysics Data System (ADS)

Elastic scattering experiments have being performed with low-energy radioactive ion beams produced by the RIBRAS facility in Sao Paulo, Brazil. Here I present the results for elastic scattering of 6He on several targets and light beams on 12C target. Special emphasis is given to the analysis of experiments were angular distributions for the elastic scattering of beryllium isotopes projectiles, 7Be, 9Be and 10Be, on a light target 12C were obtained. These elastic scattering angular distributions have been analysed in terms of optical model using the double-folding Sao Paulo potential. From this analysis, the total reaction cross section were also deduced and compared to the total reaction cross sections for many other light projectiles on 12C target. The comparison was made in terms of Universal Function reduction method.

Guimarães, Valdir

2011-10-01

46

Estimating Disaggregated Price Elasticities in Industrial Energy Demand  

Microsoft Academic Search

Econometric energy models are used to evaluate past policy experiences, assess the impact of future policies and forecast energy demand. This paper estimates an industrial energy demand model for the province of Ontario using a linear-logit specification for fuel type equations which are embedded in an aggregate energy demand equation. Short-term, long-term, own- and cross-price elasticities are estimated for electricity,

Mahmoud A. T. Elkhafif

1992-01-01

47

Gravitational potential as a source of earthquake energy  

USGS Publications Warehouse

Some degree of tectonic stress within the earth originates from gravity acting upon density structures. The work performed by this "gravitational tectonics stress" must have formerly existed as gravitational potential energy contained in the stress-causing density structure. According to the elastic rebound theory (Reid, 1910), the energy of earthquakes comes from an elastic strain field built up by fairly continuous elastic deformation in the period between events. For earthquakes resulting from gravitational tectonic stress, the elastic rebound theory requires the transfer of energy from the gravitational potential of the density structures into an elastic strain field prior to the event. An alternate theory involves partial gravitational collapse of the stress-causing density structures. The earthquake energy comes directly from a net decrease in gravitational potential energy. The gravitational potential energy released at the time of the earthquake is split between the energy released by the earthquake, including work done in the fault zone and an increase in stored elastic strain energy. The stress associated with this elastic strain field should oppose further fault slip. ?? 1981.

Barrows, L.; Langer, C. J.

1981-01-01

48

Elastic electron scattering from the antimony atom in the spin-polarized optical potential approach  

NASA Astrophysics Data System (ADS)

This is the first theoretical study of elastic scattering of electrons on antimony atoms in a broad range of low and intermediate collision energies from 0.1 eV to 1 keV. A complex optical potential (OP) in the spin-polarized approximation is used for the calculation of differential (DCSs) and integral scattering cross sections as well as a spin exchange asymmetry parameter. It is shown that for this atom the spin dependence of not only exchange interaction, but also polarization interaction should be taken into account at the asymmetry calculation. Two types of absorption potential are used: a non-empirical potential within the quasi-free electron scattering approximation and a McCarthy-type empirical potential. The calculations are also performed without taking account of absorption effects, i.e. in the approximation of solely the parameter-free real part of the OP. Characteristics of the antimony atom and spin correlation-polarization potentials are found using the local spin density approximation. Energy and angular positions of 11 critical minima in the DCSs are found. The highest energy minimum among them is located at [663.2 eV; 132.02°]. In the angular vicinities of the critical minima, spin polarization parameters, the Sherman function S(?) and the U(?) function are calculated. The present DCSs and S(?) are compared with other available theoretical and experimental data.

Kelemen, V. I.; Remeta, E. Yu

2010-12-01

49

Theory of Proton Elastic Scattering from Finite Nuclei at Intermediate Energies.  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. The theory of the optical potential for proton scattering at intermediate energies is discussed in detail. The first and second order terms of the KMT multiple scattering optical potentials are calculated for proton scattering from light nuclei in the intermediate energy region (135-300MeV). A momentum space method is developed which allows the study of all the nonlocalities of the potential. A practical numerically stable approximate procedure for the treatment of the Coulomb interaction in momentum space calculations is discussed. The accuracy of the method is compared with other prescriptions in the literature and is shown to produce accurate calculations of scattering observables. The first order term of the KMT optical potential is calculated for proton elastic scattering from ^{16}O and ^{40 }Ca. Several approximate treatments of this potential are analysed. In particular it is shown that, using a free nucleon-nucleon transition amplitude with energy fixed at half of the incident beam energy, the optimal factorization provides a good approximation to the full folding potential in the description of the elastic scattering observables. The second order corrections to the KMT optical potential for the elastic scattering of protons from ^{16}O are calculated at 135, 200 and 300 MeV incident energies, paying particular importance to the nonlocalities inherent in the potential. It is shown that these nuclear medium effects result in a significant reduction in the proton-target absorption and modifies the elastic scattering wave function in the interior of the nucleus.

Crespo, Raquel

50

High Energy Elastic Hadron Scattering. Experiment, Data and Theoretical Descriptions.  

National Technical Information Service (NTIS)

The paper deals with the WA7 experiment at the CERN super proton synchrotron (SPS). The elastic differential cross sections of pion-proton, kaon-proton, antiproton-proton, and proton-proton at lower SPS energies over a wide range of momentum transfer were...

T. A. Fearnly

1986-01-01

51

Elastic {alpha} scattering on {sup 112}Sn and {sup 124}Sn at astrophysically relevant energies  

SciTech Connect

The cross sections for the elastic scattering reactions {sup 112,124}Sn({alpha},{alpha}){sup 112,124}Sn at energies above and below the Coulomb barrier are presented and compared to predictions for global {alpha}-nucleus potentials. The high precision of the new data allows a study of the global {alpha}-nucleus potentials at both the proton- and neutron-rich sides of an isotopic chain. In addition, local {alpha}-nucleus potentials have been extracted for both nuclei and used to reproduce elastic scattering data at higher energies. Predictions from the capture cross section of the reaction {sup 112}Sn({alpha},{gamma}){sup 116}Te at astrophysically relevant energies are presented and compared to experimental data.

Galaviz, D.; Mohr, P.; Zilges, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Fueloep, Zs.; Gyuerky, Gy.; Mate, Z.; Somorjai, E. [ATOMKI, P.O. Box 51, H-4001 Debrecen (Hungary); Rauscher, T. [Departement fuer Physik und Astronomie, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

2005-06-01

52

Model-potential approach to positron elastic scattering from noble gases  

NASA Astrophysics Data System (ADS)

In a recent publication [D. Assafrão , Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.84.022713 84, 022713 (2011)] a model-potential approach was proposed to positron-atom scattering based on an adiabatic method that treats the positron as a light nucleus. In this paper the formalism is further improved by the introduction of semiempirical energy terms which appropriately account for the positron-target interaction at long and short ranges. Our method allows us to describe the main observed features of the elastic cross sections for positron scattering from He, Ne, Ar, Kr, and Xe. Valuable insights into the cross-section behavior below the positronium formation threshold, the scattering lengths, and other aspects of the low-energy positron-noble gases scattering are presented.

Poveda, Luis A.; Dutra, Adriano; Mohallem, José R.; Assafrão, Denise

2013-05-01

53

A Study of Intermediate Energy Proton-16O Elastic Scattering Based on the ?-Particle Model  

NASA Astrophysics Data System (ADS)

In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-16O elastic scattering is presented based on the ? particle model of 16O. The differential cross sections, the analyzing powers, and the total cross sections of the intermediate energy proton-16O scattering have been calculated by using the obtained optical potential. The main features of the measured angular distributions of the cross section and the analyzing power can be well described. The calculated total cross sections are in good agreement with the experimental data at energies below 0.7 GeV and underestimate the data about 8% at higher energies.

Zhang, Rong; Yang, Yong-Xu; Lu, Xiao; Li, Qing-Run

2007-04-01

54

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

SciTech Connect

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.

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

55

Elastic positron-cadmium scattering at low energies  

SciTech Connect

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{sup +}-Cd system. The s-wave binding energy is estimated to be 126{+-}42 meV, with a scattering length of A{sub scat}=(14.2{+-}2.1)a{sub 0}, while the threshold annihilation parameter, Z{sub eff}, was 93.9{+-}26.5. The p-wave phase shift exhibits a weak shape resonance that results in a peak Z{sub eff} of 91{+-}17 at a collision energy of about 490{+-}50 meV.

Bromley, M. W. J.; Mitroy, J. [Department of Physics and Computational Science Research Center, San Diego State University, San Diego, California 92182 (United States); ARC Centre for Antimatter-Matter Studies and School of Engineering, Charles Darwin University, Darwin, Northern Territory 0909 (Australia)

2010-05-15

56

Continuum limits of atomistic energies allowing smooth and sharp interfaces in 1D elasticity  

Microsoft Academic Search

In this paper we present two atomistic models for the energy of a\\u000aone-dimensional elastic crystal. We assume that the macroscopic displacement\\u000aequals the microscopic one. The energy of the first model is given by a\\u000atwo-body interaction potential, and we assume that the atoms follow a\\u000acontinuous and piecewise smooth macroscopic (continuum) deformation. We\\u000acalculate the first terms of

Carlos Mora-Corral

2009-01-01

57

The Price Elasticity of Residential Energy Use.  

National Technical Information Service (NTIS)

The conclusions of this paper are offered as conjectures rather than as matters of fact, since they rest upon a number of interesting clues rather than decisive proofs. With respect to estimation techniques: Aggregation across different household energy-u...

K. P. Anderson

1974-01-01

58

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

SciTech Connect

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.

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

59

Global Biomass Energy Potential  

Microsoft Academic Search

The intensive use of renewable energy is one of the options to stabilize CO2atmospheric concentration at levels of 350 to 550ppm. A recent evaluation of the global potential of primary renewable energy\\u000a carried out by Intergovernmental Panel on Climate Change (IPCC) sets a value of at least 2800EJ\\/yr, which is more than the\\u000a most energy-intensive SRES scenario forecast for the

Rua Francisco Dias Velho

2006-01-01

60

Antiproton-induced elastic and inelastic scattering at intermediate energies  

SciTech Connect

With the construction and subsequent operation of LEAR, beams of low-energy antiproton with previously unobtainable intensity and quality were possible. Elastic and inelastic scattering experiments were performed on several nuclei in both the p- and sd-shell as well as targets of heavier mass. In the very near future experiments with antiproton having momentum of up to 2 Gev/c will be possible. It is the purpose of this brief article to report results of initial calculations of {anti p}-nucleus scattering for energies that span this new energy region and for which the elementary {anti p}N amplitudes are known. 4 figs.

Ma, W.H.; Strottman, D.D.

1991-01-01

61

Quasi-elastic reactions at energies close to the barrier  

SciTech Connect

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.

Rehm, K.E.

1988-01-01

62

Elastic scattering of low-energy electrons by benzene  

SciTech Connect

We present elastic cross sections obtained from ab initio calculations for low-energy electron scattering by benzene, C{sub 6}H{sub 6}. The calculations employed the Schwinger multichannel method as implemented for parallel computers within both the static-exchange and static-exchange-polarization approximations. We compare our results with other theoretical calculations and with available experimental data. In general, agreement is good. (c) 2000 American Institute of Physics.

Bettega, M. H. F. [A. A. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States); Winstead, C. [A. A. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States); McKoy, V. [A. A. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States)

2000-05-22

63

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

NASA Astrophysics Data System (ADS)

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.

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

64

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

SciTech Connect

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.

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

65

Simple model potential for the description of elastic properties of single-layer graphene  

NASA Astrophysics Data System (ADS)

A model potential for the description of elastic properties of single-layer graphene has been proposed. The potential is reduced to the two-dimensional Keating model at a small strain, but is also applicable to the description of the response of graphene to a finite in-plane strain.

Davydov, S. Yu.

2013-04-01

66

Comparison of Electron Elastic-Scattering Cross Sections Calculated from Two Commonly Used Atomic Potentials  

Microsoft Academic Search

We have analyzed differential cross sections (DCSs) for the elastic scattering of electrons by neutral atoms that have been derived from two commonly used atomic potentials: the Thomas–Fermi–Dirac (TFD) potential and the Dirac–Hartree–Fock (DHF) potential. DCSs from the latter potential are believed to be more accurate. We compared DCSs for six atoms (H, Al, Ni, Ag, Au, and Cm) at

A. Jablonski; F. Salvat; C. J. Powell

2004-01-01

67

Analytical potential for the elastic scattering of light halo nuclei below and close to the Coulomb barrier  

SciTech Connect

An analytical expression for the dynamic polarization potential is derived for the elastic scattering of light halo nuclei in the Coulomb field of heavy targets. The derivation is based on the adiabatic motion of the projectile below and close to the Coulomb barrier together with a uniform approximation for the Coulomb functions. Detailed computations have been carried out for the elastic scattering of d+{sup 208}Pb and {sup 6}He+{sup 208}Pb at collision energies of 8 and 17.8 MeV and are compared with measurements as far as available. The obtained expression for the dynamic polarization potential is simple and can be applied for any arbitrary system with a dineutron configuration.

Borowska, L. [Universitaet Bonn, Auf dem Huegel 20, D-53121 Bonn (Germany); Institute for Nuclear Research, National Academy of Sciences of Ukraine, Nauky Prospekt 47, 03680 Kyiv (Ukraine); Terenetsky, K.; Verbitsky, V. [Institute for Nuclear Research, National Academy of Sciences of Ukraine, Nauky Prospekt 47, 03680 Kyiv (Ukraine); Fritzsche, S. [Gesellschaft fuer Schwerionenforschung (GSI), Planckstrasse 1, D-64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main (Germany)

2009-04-15

68

Salinity effects on water potential components and bulk elastic modulus of Alternanthera philoxeroides (Mart. ) Griseb  

Microsoft Academic Search

Pressure volume curves for Alternanthera philoxeroides (Mart.) Grixeb. (alligator weed) grown in 0 to 400 millimolar NaCl were used to determine water potential (PSI), osmotic potential (psi\\/sub s\\/), turgor potential (psi\\/sub p\\/) and the bulk elastic modulus (element of) of shoots at different tissue water contents. Values of psi decreased with increasing salinity and tissue PSI was always lower than

J. A. Bolanos; D. J. Longstreth

1984-01-01

69

Analytical Treatment of Boundary Integrals in Direct Boundary Element Analysis of Plan Potential and Elasticity Problems  

Microsoft Academic Search

An analytical scheme, which avoids using the standard Gaussian approximate quadrature to treat the boundary integrals in direct boundary element method (DBEM) of two-dimensional potential and elastic problems, is established. With some numerical results, it is shown that the better precision and high computational efficiency, especially in the band of the domain near boundary, can be derived by the present

Yao-ming Zhang; Huan-chun Sun

2001-01-01

70

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

NASA Astrophysics Data System (ADS)

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.

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

71

Elastic scattering of {sup 9}Li on {sup 208}Pb at energies around the Coulomb barrier  

SciTech Connect

We have studied the dynamical effects of the halo structure of {sup 11}Li 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 {sup 11}Li beam. As part of this study we report here on the first measurement of the elastic cross section of the core nucleus, i.e. {sup 9}Li on {sup 208}Pb, 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.

Cubero, M. [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); CICANUM, Universidad de Costa Rica, Apdo. 2060, San Jose (Costa Rica); Fernandez-Garcia, J. P.; Alvarez, M. A. G. [Departamento de FAMN, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla (Spain); Centro Nacional de Aceleradores, Avda. Thomas A. Edison, E-41092, Sevilla (Spain); Lay, J. A.; Moro, A. M. [Departamento de FAMN, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla (Spain); Acosta, L.; Martel, I.; Sanchez-Benitez, A. M. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Huelva (Spain); Alcorta, M.; Borge, M. J. G.; Tengblad, O. [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Buchmann, L.; Shotter, A.; Walden, P. [TRIUMF, V6T2A3 Vancouver B.C. (Canada); Diget, D. G.; Fulton, B. [Department of Physics, University of York, YO10 5DD Heslington, York (United Kingdom); Fynbo, H. O. U. [Department of Physics and Astronomy, University ofAarhus, DK-8000, Aarhus (Denmark); Galaviz, D. [Centro de Fisica Nuclear da Universidade de Lisboa, 1649-003 Lisbon (Portugal); Gomez-Camacho, J. [Centro Nacional de Aceleradores, Avda. Thomas A. Edison, E-41092, Sevilla (Spain); Departamento de FAMN, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla (Spain); Mukha, I. [Instituto de Fisica Corpuscular, CSIC-Universidadde Valencia (Spain)

2011-10-28

72

Partial-Wave Scattering by Non-Spherically-Symmetric Potentials. I. General Theory of Elastic Scattering  

Microsoft Academic Search

A general method is developed to obtain the elastic-scattering cross section of an asymmetric potential V(r)=lvl(r)Pl(Omega^l.r^) where we have expanded the potential as a sum of multipoles and Omega^l is a unit vector along the 2l-pole axis. We assume that vl(r) is effectively zero beyond a cutoff radius R and we solve the resulting set of coupled differential equations in

A. D. Boardman; A. D. Hill; S. Sampanthar

1967-01-01

73

Proton-proton elastic scattering excitation functions at intermediate energies  

NASA Astrophysics Data System (ADS)

Polarized and unpolarized proton-proton elastic scattering is investigated with the EDDA-experiment at the Cooler Synchrotron COSY at Jülich to significantly improve the world data base in the beam energy range 500-2500 MeV. Measurements during beam acceleration with thin internal targets and a large acceptance detector provide excitation functions over a broad angular and energy range with unprecedented internal consistency. Data taking with an unpolarized CH2 fiber target and an unpolarized beam have been completed and the derived differential cross sections are presented and compared to a recent phase shift analysis. With a polarized atomic beam target newly installed in COSY and a polarized COSY beam-currently under development-the measurements will be extended to analyzing powers and spin correlation parameters.

Rohdjess, H.

1998-05-01

74

Low-energy elastic electron scattering from furan  

NASA Astrophysics Data System (ADS)

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.

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

2010-06-01

75

Anchoring energy and orientational elasticity of a ferroelectric liquid crystal  

SciTech Connect

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).

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

76

Human elasticity  

NASA Astrophysics Data System (ADS)

The elasticity of the Achilles tendon and of the arch of the foot saves energy in running, enabling us to bounce along like rubber balls. Also the elastic compliance of the heel cushions impacts with the ground.

McNeill Alexander, R.

1994-11-01

77

Human elasticity  

Microsoft Academic Search

The elasticity of the Achilles tendon and of the arch of the foot saves energy in running, enabling us to bounce along like rubber balls. Also the elastic compliance of the heel cushions impacts with the ground.

R. McNeill Alexander

1994-01-01

78

Disorder-driven critical behavior of periodic elastic media in a crystal potential.  

PubMed

A lattice model of a three-dimensional periodic elastic medium at zero temperature is studied with exact combinatorial optimization methods. A competition between pinning of the elastic medium, representing magnetic flux lines in a superconductor or charge density waves in a crystal, by randomly distributed impurities and a periodic lattice potential gives rise to a continuous roughening transition from a flat to a rough phase. A finite size scaling analysis yields the critical exponents nu approximately 1.3, beta approximately 0.05, gamma/nu approximately 2.9 that are universal with respect to the periodicity of the lattice potential. The small order parameter exponent is reminiscent of the random field Ising critical behavior in 3D. PMID:11690283

Noh, J D; Rieger, H

2001-10-04

79

Response of the potential of a gold electrode to elastic strain.  

PubMed

We describe the measurement of the response, sigma, of the potential of a metal electrode to elastic strain under open circuit conditions. The experimental response exhibits a frequency dependence due to Faraday loss currents, which become negligible beyond 30 Hz. For a (111)-textured gold film the experimental value at higher frequency, sigma = -1.83 V, compares well with the intrinsic value of Au(111) predicted by recent ab initio computation. PMID:19812819

Smetanin, M; Kramer, D; Mohanan, S; Herr, U; Weissmüller, J

2009-08-21

80

Solution for boson-diboson elastic scattering at zero energy in the shape-independent model  

SciTech Connect

We derive an exact analytic expression for the boson-diboson elastic scattering phase shift in the shape-independent model for positive two-body scattering lengths when the total energy vanishes. A three-body hard-core potential depending upon a hyperradial cutoff parameter R{sub 0} is introduced to obtain a finite result. The exact result is compared with adiabatic hyperspherical calculations of the phase shift, and a similar functional dependence on the cutoff parameter is found. The cutoff parameter plays the role of a renormalization constant in that it renormalizes the wave function at vanishing hyperradius.

Macek, J.H.; Ovchinnikov, Serge; Gasaneo, Gustavo [Department of Physics and Astronomy, University of Tennessee, Knoxville Tennessee 37996-1501 (United States) and Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6372 (United States); Departamento de Fisica, Universidad Nacional del Sur, Av. Alem1253 (8000) Bahia Blanca, Buenos Aires (Argentina)

2005-09-15

81

7Be, 8B+208Pb Elastic Scattering at Above-Barrier Energies  

NASA Astrophysics Data System (ADS)

Angular distributions for the elastic scattering of 7Be and 8B by an enriched 208Pb target were measured at the Radioactive Ion Beam Line at Lanzhou (RIBLL). The incident energies of the radioactive beams were about three times the respective Coulomb barriers. A suppressed Coulomb-nuclear Interference Peak (CNIP) is not observed for 8B, a pronounced proton halo nucleus. Optical model fits were performed using Woods-Saxon potentials and the total reaction cross sections deduced. The results are discussed.

Wang, J. S.; Yang, Y. Y.; Wang, Q.; Jin, L.; Ma, J. B.; Huang, M. R.; Han, J. L.; Ma, P.; Jin, S. L.; Bai, Z.; Hu, Q.; Chen, J. B.; Wada, R.; Sun, Z. Y.; Chen, R. F.; Zhang, X. Y.; Hu, Z. G.; Yuan, X. H.; Cao, X. G.; Xu, Z. G.; Xu, S. W.; Zhen, C.; Chen, Z. Q.; Chen, Z.; Chen, S. Z.; Du, C. M.; Duan, L. M.; Fu, F.; Gou, B. X.; Hu, J.; He, J. J.; Lei, X. G.; Li, S. L.; Li, Y.; Lin, Q. Y.; Liu, L. X.; Shi, F. D.; Tang, S. W.; Xu, G.; Zhang, L. Y.; Zhang, X. H.; Zhang, W.; Zhao, M. H.; Zhang, Y. H.; Xu, H. S.; Xiao, G. Q.; Mukhejee, S.; Keeley, N.; Rusek, K.; Pang, D. Y.

2013-03-01

82

Microscopic study on proton elastic scattering of light exotic nuclei at energies below than 100 MeV/nucleon  

NASA Astrophysics Data System (ADS)

The proton elastic scattering data on some light exotic nuclei, namely, 6, 8He, 9, 11Li, and 10, 11, 12Be, at energies below than 100MeV/nucleon are analyzed using the single folding optical model. The real, imaginary, and spin-orbit parts of the optical potential (OP) are constructed only from the folded potentials and their derivatives using M3Y effective nucleon-nucleon interaction. These OP parts, their renormalization factors and their volume integrals are studied. The surface and spin-orbit potentials are important to fit the experimental data. Three model densities for halo nuclei are used and the sensitivity of the cross-sections to these densities is tested. The imaginary OP within high-energy approximation is used and compared with the single folding OP. This OP with few and limited fitting parameters, which have systematic behavior with incident energy, successfully describes the proton elastic scattering data with exotic nuclei.

Farag, M. Y. H.; Esmael, E. H.; Maridi, H. M.

2012-11-01

83

Magneto-elasticity in hydrogels containing Fe3O4 nanoparticles and their potential applications  

NASA Astrophysics Data System (ADS)

The magnetic hydrogels have been fabricated via standard method of polymer preparation. Hydrogels were the mixture of polyvinyl alcohol (PVA) and water by certain ratio of mass. Magnetism in hydrogels was presented by introduction of magnetic Fe3O4 nanoparticles with crystal size ranging from 11 nm to 15 nm, prepared by coprecipitation technique from iron-sands. According to the magnetic induction experiment, it has shown that the magneto-elasticity of gels containing Fe3O4 of around 2.5% - 15% tends to decrease as increasing Fe3O4 concentration. The magneto-elasticity responses of the gels clearly form hysteresis in the increasing and decreasing applied magnetic field, where in turn open the potential applications of these magnetic hydrogels.

Sunaryono; Taufiq, Ahmad; Munaji; Indarto, Bahtera; Triwikantoro; Zainuri, Mochamad; Darminto

2013-09-01

84

Elastic energy loss and longitudinal straggling of a hard jet  

SciTech Connect

The elastic energy loss encountered by jets produced in deep-inelastic scattering (DIS) off a large nucleus is studied in the collinear limit. In close analogy to the case of (nonradiative) transverse momentum broadening, which is dependent on the medium transport coefficient q, a class of medium enhanced higher twist operators which contribute to the nonradiative loss of the forward light-cone momentum of the jet (q{sup -}) are identified and the leading correction in the limit of asymptotically high q{sup -} is isolated. Based on these operator products, a new transport coefficient e is motivated which quantifies the energy loss per unit length encountered by the hard jet. These operator products are then computed, explicitly, in the case of a similar hard jet traversing a deconfined quark-gluon plasma (QGP) in the hard-thermal-loop (HTL) approximation. This is followed by an evaluation of subleading contributions which are suppressed by the inverse light-cone momentum q{sup -}, which yields the longitudinal 'straggling', i.e., a slight change in light cone momentum due to the Brownian propagation through a medium with a fluctuating color field.

Majumder, A. [Department of Physics, Duke University, Durham, North Carolina 27708 (United States) and Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States)

2009-09-15

85

Propagation of elastic energy in a general anisotropic medium  

Microsoft Academic Search

Propagation of plane harmonic waves is studied in anisotropic elastic medium. Anisotropy is of general type, i.e., no symmetry enforced and no rotation of elastic tensor. The propagation is not restricted to a fixed plane but along a general direction in three-dimensional space. A new procedure is presented to study the reflection in anisotropic media. Phase direction of incident wave

M. D. Sharma

2007-01-01

86

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

PubMed Central

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.

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

2009-01-01

87

Analysis of dermal elastic fibers in the absence of fibulin-5 reveals potential roles for fibulin-5 in elastic fiber assembly.  

PubMed

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 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

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

2009-03-24

88

Turkey's Biogas Energy Potential  

Microsoft Academic Search

As in the rest of the world, in Turkey it is necessary to utilize the renewable energy sources to make up for the increasing energy deficit. As an alternative to these energy sources, the use of biogas seems possible. Even when it is considered only with regards to the animal husbandry sector, the majority of the manure obtained is a

N. Kizilaslan; H. Kizilaslan

2007-01-01

89

Investigating Kinetic and Potential Energy  

NSDL National Science Digital Library

Students use media resources and an in-class investigation to explore the types of energy within different types of systems. They also use the formulas for kinetic and potential energy to examine the path of a projectile.

Foundation, Wgbh E.

2007-04-19

90

Inverted potential by the phase-integral method: He-Na elastic scattering  

SciTech Connect

The phase-integral approximation is used in the frame of the inverse scattering theory to reconstruct a potential of the type v=v{sub 1}+v{sub 2} in which one component v{sub 1} is assumed to be known a priori. It is shown that from the knowledge of this term and the phase shift, an analytic expression of the unknown term v{sub 2} can be derived. A number of suggestions in order to enlarge the range of applications of this method are also presented. The case of He-Na elastic scattering is given as an example.

Zerarka, A.; Boumedjane, Y.; Hans, J. [Departement de Physique Theorique, Universite Med Khider, B. P. 145, Biskra 07000 (Algeria)

2002-11-01

91

Elastic and vibrational properties of group IV semiconductors in empirical potential modelling.  

PubMed

We have developed an interatomic potential that with a single set of parameters is able to accurately describe at the same time the elastic, vibrational and thermodynamics properties of semiconductors. The simultaneous inclusion of radial and angular forces of the interacting atom pairs (short range) together with the influence of the broken crystal symmetry when the atomic arrangement is out of equilibrium (long range) results in correct predictions of all of the phonon dispersion spectrum and mode-Grüneisen parameters of silicon and germanium. The long range interactions are taken into account up to the second nearest neighbours, to correctly influence the elastic and vibrational properties, and therefore represent only a marginal computational cost compared to the full treatment of other proposed potentials.Results of molecular dynamics simulations are compared with those of ab initio calculations, showing that when our proposed potential is used to perform the initial stages of the structural relaxation, a significant reduction of the computational time needed during the geometry optimization of density functional theory simulations is observed. PMID:24065386

Monteverde, U; Migliorato, M A; Pal, J; Powell, D

2013-09-24

92

Elastic and vibrational properties of group IV semiconductors in empirical potential modelling  

NASA Astrophysics Data System (ADS)

We have developed an interatomic potential that with a single set of parameters is able to accurately describe at the same time the elastic, vibrational and thermodynamics properties of semiconductors. The simultaneous inclusion of radial and angular forces of the interacting atom pairs (short range) together with the influence of the broken crystal symmetry when the atomic arrangement is out of equilibrium (long range) results in correct predictions of all of the phonon dispersion spectrum and mode-Grüneisen parameters of silicon and germanium. The long range interactions are taken into account up to the second nearest neighbours, to correctly influence the elastic and vibrational properties, and therefore represent only a marginal computational cost compared to the full treatment of other proposed potentials. Results of molecular dynamics simulations are compared with those of ab initio calculations, showing that when our proposed potential is used to perform the initial stages of the structural relaxation, a significant reduction of the computational time needed during the geometry optimization of density functional theory simulations is observed.

Monteverde, U.; Migliorato, M. A.; Pal, J.; Powell, D.

2013-10-01

93

Angular distributions of elastic scattering of ?- hyperons from nuclei and the ?-nucleus potentials  

NASA Astrophysics Data System (ADS)

We theoretically investigate the elastic scattering of 50-MeV ?- hyperons from 28Si and 208Pb in order to clarify the radial distribution of ?-nucleus (optical) potentials. The angular distributions of differential cross sections are calculated using several potentials that can explain experimental data of the ?- atomic x-ray and (?-, K+) reaction spectra simultaneously. The magnitude and oscillation pattern of the angular distributions are understood by the use of nearside/farside decompositions of their scattering amplitudes. It is shown that the resultant angular distributions provide a clue to discriminating among the radial distributions of the potentials that have a repulsion inside the nuclear surface and an attraction outside the nucleus with a sizable absorption.

Harada, Toru; Hirabayashi, Yoshiharu

2012-07-01

94

Partial-wave analysis for elastic p{sup 13}C scattering at astrophysical energies  

SciTech Connect

A standard partial-wave analysis was performed on the basis of known measurements of differential cross sections for elastic p{sup 13}C scattering at energies in the range 250-750 keV. This analysis revealed that, in the energy range being considered, it is sufficient to take into account the {sup 3}S{sub 1} wave alone. A potential for the triplet {sup 3}S{sub 1}-wave state of the p{sup 13}C system in the region of the J{sup p}T = 1{sup -1} resonance at 0.55 MeV was constructed on the basis of the phase shifts obtained from the aforementioned partial-wave analysis.

Dubovichenko, S. B., E-mail: dubovichenko@mail.ru [V.G. Fessenkov Astrophysical Institute (Kazakhstan)

2012-03-15

95

Ring formation mechanism of single-walled carbon nanotubes: Energy conservation between curvature elasticity and inter-tube adhesion  

NASA Astrophysics Data System (ADS)

Rings of single-walled carbon nanotubes (SWNTs) exist widely during water evaporation from their dispersions at low concentration on such substrates as silica wafer. We examine the phenomenon in terms of energy conservation between the increased significant curvature energy and the inherent inter-tube van der Waals (vdW) attraction potentials. And thereby, the observed multi ring structures for coarse and long SWNT bundles have also gained detailed interpretation. We conclude that carbon nanotubes (CNTs) coil into rings by their own elastic mechanism. The formed rings with different width and diameters originate from appropriate sizes of SWNTs or the bundles. Specially, the associated elasticity may have prospective potentials to reveal other fascinating self-assembling phenomenon on CNTs, for instance, the known liquid crystallinity of them. Besides, we have also analyzed the external factors to the ring formation, both statistically and dynamically.

Chang, C. R.; Lu, L. H.; Liu, J. H.; Chen, W.

2012-01-01

96

Elastic energy loss with respect to the reaction plane in a Monte Carlo model  

SciTech Connect

We present a computation of {pi}{sup 0} nuclear modification factor with respect to the reaction plane in Au+Au collisions at {radical}(s{sub NN})=200 GeV, based on a Monte Carlo model of elastic energy loss of hard partons traversing the bulk hydrodynamical medium created in ultrarelativistic heavy-ion collisions. We find the incoherent nature of elastic energy loss incompatible with the measured data.

Auvinen, Jussi; Eskola, Kari J.; Holopainen, Hannu; Renk, Thorsten [Department of Physics, P.O. Box 35, University of Jyvaeskylae, FI-40014 Jyvaeskylae, Finland and Helsinki Institute of Physics, P.O. Box 64, University of Helsinki, FI-00014 Helsinki (Finland)

2010-11-15

97

Energy and the Pogo Stick  

NSDL National Science Digital Library

This activity utilizes hands on learning with the conservation of energy with the inclusion of elastic potential energy. Students use pogo sticks to experience the elastic potential energy and its conversion to gravitational potential energy.

Vu Bioengineering Ret Program

98

A critical assessment of interatomic potentials for ceria with application to its elastic properties  

Microsoft Academic Search

We critically assess the materials fidelity of six interatomic potentials for ceria, based on predicted lattice constants, thermal expansion, chemical expansion, dielectric properties, oxygen migration energy and mechanical properties. While, no potential can reproduce all fundamental properties, the Gotte (2007) and Grimes potentials display the combination of highest fidelity with the widest range of applicability. The simulations show that sub-stoichiometry

Rakesh K. Behera; Fereshteh Ebrahimi; Susan B. Sinnott; Eric D. Wachsman; Simon R. Phillpot

2010-01-01

99

Analysis of the nuclear potential for heavy-ion systems through large-angle quasi-elastic scattering  

NASA Astrophysics Data System (ADS)

A study on the surface diffuseness parameter of the nuclear potential for the reactions of 208Pb with 48Ti, 54Cr, 56Fe, 64Ni, and 70Zn is performed using large-angle quasi-elastic scattering experimental data. Diffuseness parameters that are considerably lower than the standard value of around 0.63 fm are required in order to fit the experimental data at deep sub-barrier energies, except for the 54Cr+208Pb system, where the required diffuseness parameter is in satisfactory agreement with (but still lower than) the standard value. Furthermore, when the energies of the experimental data used in the fittings are increased from the deep sub-barrier region to the energies closer to the Coulomb barrier height, the best fitted diffuseness parameters also increase. The increase in the obtained diffuseness parameters as the energies are increased also seems to have a possible tendency to be a function of the charge product of the target and projectile nuclei. We find that the phenomenon of threshold anomaly might explain our findings here. The increase in the diffuseness parameters could also due to dynamical effects, for example, due to neutron movements.

Inche Ibrahim, M. L.; Zamrun, Muhammad; Kassim, Hasan Abu

2013-02-01

100

Free Energy of Rigid Rods: Contribution of Rotational Entropy to Frank Elasticity  

NASA Astrophysics Data System (ADS)

We apply the density functional formalism developed by the present authors [J. Fukuda and H. Yokoyama: J. Chem. Phys. 115 (2001) 4930] for the calculation of the free energy of rigid rods as a functional of the compositional scalar order parameter ? and the orientational order parameter of second-rank tensor Qij We model rigid rods as semiflexible wormlike chains with infinite bending elasticity and the exact expression for the entropic part of the free energy up to the second order in the gradients can be obtained. Discussion is devoted to the contribution of rotational entropy to Frank elasticity. Although none of the previous molecular theories for the Frank elasticity of liquid crystals has taken rotational entropy into account, our results indicate that rotational entropy can give a non-negligible contribution to Frank elasticity.

Fukuda, Jun-ichi; Yokoyama, Hiroshi

2002-06-01

101

Elastic scattering of electrons on Ne atoms at intermediate energies  

NASA Astrophysics Data System (ADS)

In this work, we present a theoretical study on electron scattering by Ne in the intermediate- and high-energy range. More specifically, we report calculated differential cross sections for electron scattering by Ne in the 20-500 eV range by the Schwinger multichannel method using plane waves as a trial basis set. To include exchange plus polarization effects, we used the Born-Ochkur model and the Buckingham potential, respectively. The comparison of our calculated results with experimental data and recent theoretical studies (Jablonski et al 2004 J. Phys. Chem. Ref. Data 33 409) is encouraging.

Lino, Jorge L. S.

2010-03-01

102

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

SciTech Connect

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.

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

103

Nucleation rate of critical droplets on an elastic string in a {phi}{sup 6} potential  

SciTech Connect

We obtain the nucleation rate of critical droplets for an elastic string moving in a {phi}{sup 6} 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 critical droplet are obtained from a Heun equation. We solve the Fokker-Planck equation for the phase-space probability density by projecting it onto the eigenfunction basis obtained from the Heun equation. We employ Farkas' 'flux-overpopulation' method to obtain boundary conditions for solving the Fokker-Planck equation; these restrict the validity of our solution to the moderate to heavy damping regime. We present results for the rate as a function of temperature, well depth, and damping.

Kerr, W.C.; Graham, A.J. [Olin Physical Laboratory, Wake Forest University, Winston-Salem, North Carolina 27109-7507 (United States); Department of Physics and Astronomy, Appalachian State University, Boone, North Carolina 28608 (United States)

2004-12-01

104

Nucleation rate of critical droplets on an elastic string in a phi6 potential.  

PubMed

We obtain the nucleation rate of critical droplets for an elastic string moving in a phi(6) 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 critical droplet are obtained from a Heun equation. We solve the Fokker-Planck equation for the phase-space probability density by projecting it onto the eigenfunction basis obtained from the Heun equation. We employ Farkas' "flux-overpopulation" method to obtain boundary conditions for solving the Fokker-Planck equation; these restrict the validity of our solution to the moderate to heavy damping regime. We present results for the rate as a function of temperature, well depth, and damping. PMID:15697430

Kerr, W C; Graham, A J

2004-12-02

105

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

106

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

PubMed Central

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.

2011-01-01

107

Energy trapping in power transmission through a circular cylindrical elastic shell by finite piezoelectric transducers.  

PubMed

We study the transmission of electric energy through a circular cylindrical elastic shell by acoustic wave propagation and piezoelectric transducers. Our mechanics model consists of a circular cylindrical elastic shell with finite piezoelectric patches on both sides of the shell. A theoretical analysis using the equations of elasticity and piezoelectricity is performed. A trigonometric series solution is obtained. Output voltage and transmitted power are calculated. Confinement and localization of the vibration energy (energy trapping) is studied which can only be understood from analyzing finite transducers. It is shown that when thickness-twist mode is used the structure shows energy trapping with which the vibration can be confined to the transducer region. It is also shown that energy trapping is sensitive to the geometric and physical parameters of the structure. PMID:18499207

Yang, Z T; Guo, S H

2008-04-12

108

The curvature elastic-energy function of the lipid-water cubic mesophase  

NASA Astrophysics Data System (ADS)

CELL and lipid membranes are able to bend, as manifested during membrane fusion and the formation of non-lamellar lyotropic mesopbases in water. But there is an energy cost to bending of lipid layers, called the curvature elastic energy. Although the functional form of this energy is known1, a complete quantitative knowledge of the curvature elastic energy, which is central to predicting the relative stability of the large number of phases that lipid membranes can adopt, has been lacking. Here we use X-ray synchrotron diffraction measurements of the variation of lattice parameter with pressure and temperature for the periodic Ia3d (Q230) cubic phase of hydrated monoolein to calculate the complete curvature elastic-energy function for the lipid cubic mesophase. This allows us to predict the stabilities of different cubic and lamellar phases for this system as a function of composition.

Chung, Hesson; Caffrey, Martin

1994-03-01

109

A model of the elastic take?off energy in the long jump  

Microsoft Academic Search

A theoretical analysis of the long jump take?off is presented, with the conclusion that elastic effects are important. Measured data from the literature for groups of top athletes and average performers in the long jump confirm this conclusion and lead to an estimate of elastic energy conversion efficiency, which is very low (between 0.2 and 0.3), in contrast with much

J. Witters; W. Bohets; H. Van Coppenolle

1992-01-01

110

LHC Physics Potential versus Energy  

SciTech Connect

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.

Quigg, Chris; /Fermilab

2009-08-01

111

Biomass energy potential in Thailand  

Microsoft Academic Search

Estimation of biomass energy potential including biomass residue and forestry biomass in Thailand was carried out taking into account the amount of biomass residue which has already been used and the possibility of biomass energy plantation in accordance with the National Plan of the Thai Government. According to this estimation, 65 PJ can be derived from agricultural and forestry waste

Shin-ya Yokoyama; Tomoko Ogi; Anan Nalampoon

2000-01-01

112

Simultaneous ?2-analysis of near-barrier fusion and elastic scattering for the proton-halo system 8B + 58Ni using dynamical Woods-Saxon polarization potentials  

NASA Astrophysics Data System (ADS)

Fusion radial potential barrier for the 8B +?58Ni system is determined from a simultaneous optical model analysis of elastic scattering angular distributions and fusion data. Besides the nuclear bare potential, dynamical energy-dependent Woods-Saxon polarization potentials, i.e. UF (volume) and UDR (surface), are used. UF is a potential that accounts for polarization effects emerging from couplings to the fusion channel and UDR for effects due to direct reaction absorption couplings. Each of these potentials is split into real and imaginary potentials. The detailed physical meaning of these two terms of the optical potential is investigated. The interpretation of the results of our calculations confirms that the proton-halo characteristics of 8B enhance the fusion cross-section.

Gómez Camacho, A.; Aguilera, E. F.; Lubian, J.; Gomes, P. R. S.

2013-03-01

113

Complex angular momentum analysis of low-energy electron elastic scattering from lanthanide atoms  

SciTech Connect

Electron attachment to the lanthanide and Hf atoms resulting in the formation of stable excited lanthanide and Hf anions as Regge resonances is explored in the near-threshold electron impact energy region, E<1.0 eV. The investigation uses the recent Regge-pole methodology wherein is embedded the electron-electron correlations together with a Thomas-Fermi-type model potential incorporating the crucial core-polarization interaction. The near-threshold electron elastic total cross sections (TCSs) for the lanthanide and Hf atoms are found to be characterized by extremely narrow resonances whose energy positions are identified with the binding energies (BEs) of the resultant anions formed during the collision as Regge resonances. The extracted BEs for excited lanthanide anions are contrasted with those of the most recently calculated electron affinities (ground state BEs). We conclude that the BEs for the Pr{sup -}, Tb{sup -}, Dy{sup -}, Ho{sup -}, Er{sup -}, and Tm{sup -} anions of O'Malley and Beck [Phys. Rev. A 79, 012511 (2009)] are not identifiable with the electron affinities as claimed. Formation of bound excited anions is identified in the elastic TCSs of all the lanthanide atoms including Hf, except Eu and Gd. The imaginary part of the complex angular momentum L, ImL is used to distinguish between the shape resonances and the bound excited negative ions. These results challenge both experimentalists and theoreticians alike since the excited anions are very weakly bound, but mostly tenuously bound (BEs<0.1 eV). Shape resonances and Ramsauer-Townsend minima are also presented.

Felfli, Z.; Msezane, A. Z. [Department of Physics and Centre 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)

2010-04-15

114

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

SciTech Connect

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.

Kawano, Toshihiko [Los Alamos National Laboratory

2010-12-07

115

Is elastic energy storage of quantitative relevance for the functional morphology of the human locomotor apparatus?  

PubMed

Elastic storage of energy in the vertebrate locomotor apparatus is supposed to be an important functional factor in cyclic and acyclic movements. In terms of physics, for humans a proof for the occurrence and quantitative relevance of this phenomenon in vivo and under physiological conditions has been missing until now. In addition to the large amount of plausible, but inconclusive information about elasticity in humans and animals, we describe a simple experiment to prove the existence of quantitatively relevant elastic energy storage in the human locomotor apparatus. Ten volunteers (5 female, 5 male) each assumed a relaxed, upright posture on a steel platform. After the release of a support, the volunteers and the platform fell for a defined distance of 33 mm. Loaded with the volunteers, the platform fell significantly (p < 0.001) faster than predicted by the laws of stiff body mechanics (50 vs. 82 ms). For a minimum time of 50 ms, the human locomotor apparatus is able to support an average external power output of more than 400 W by means of an energy transfer of more than 20 J. During the fall, no EMG activities of the ankle flexors could be recorded. We conclude that the acceleration of the platform fall is induced by elastic elements serving as energy sources. Elastic energy storage is of quantitative relevance for the functional morphology and biomechanics of the human locomotor apparatus. PMID:9311419

Witte, H; Recknagel, S; Rao, J G; Wüthrich, M; Lesch, C

1997-01-01

116

Elastic micro-strain energy of austenite-martensite interface in NiTi  

NASA Astrophysics Data System (ADS)

The interfacial energy due to elastic micro-strains at the austenite-twinned martensite interface is calculated for the NiTi shape memory alloy undergoing cubic-to-monoclinic B2 <--> B19' transformation. For each crystallographically distinct microstructure, an energetically favourable local shape of the interface is determined. The approach employs finite element computations and energy minimization with respect to shape parameters, taking into account elastic anisotropy of the phases and finite-strain kinematics. The effect of atomic-scale interfacial energy is studied.

Stupkiewicz, S.; Maciejewski, G.; Petryk, H.

2012-04-01

117

Improved deuteron elastic breakup energy dependence via the continuum-discretized coupled-channels method  

SciTech Connect

Experimental elastic-scattering angular distributions for deuteron interaction with {sup 63}Cu and {sup 93}Nb targets are compared with calculations performed within the continuum-discretized coupled-channels (CDCC) method, in which coupling to breakup channels is explicitly taken into account. The calculated elastic breakup cross sections are compared with the predictions of an empirical parametrization for a wide range of deuteron incident energies. The good agreement between the calculations and the systematics at the energies where data are available indicates that the CDCC method permits a useful assessment of empirical parametrizations and provides useful guidance for the extrapolation of these parametrizations beyond the energies formerly considered.

Avrigeanu, M.; Moro, A. M. ['Horia Hulubei' National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, R-077125 Bucharest-Magurele (Romania); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain)

2010-09-15

118

Elastic modulus correction term in creep activation energies: applied to oxide dispersion strengthened superalloy  

Microsoft Academic Search

Creep properties of Inconel alloy MA 753 were studied. It was found ; that below 1500°F, where elastic modulus is weakly dependent upon ; temperature, the modulus correction term to creep activation energy is small. ; Accordingly, for superalloy systems such as INCONEL alloy MA 753 and Mar-M 200, ; which show high apparent creep activation energies at this temperature,

M. Malu; J. K. Tien

1975-01-01

119

On the theory of elastic scattering of slow particles at a 2D potential  

SciTech Connect

A theory is proposed for scattering of particles with a low energy E at an arbitrary 2D potential. This problem is solved using the expansion in the system of zero-energy eigenfunctions. Explicit expressions are obtained for the s-scattering amplitude and for the energy levels of weakly coupled s states. The general formulas derived here are illustrated with an exactly solvable example.

Balagurov, B. Ya., E-mail: balagurov@deom.chph.ras.ru [Russian Academy of Sciences, Emanuel Institute of Biochemical Physics (Russian Federation)

2012-06-15

120

Kinetic and Potential Energy of Motion  

NSDL National Science Digital Library

In this lesson, students are introduced to both potential energy and kinetic energy as forms of mechanical energy. A hands-on activity demonstrates how potential energy can change into kinetic energy by swinging a pendulum, illustrating the concept of conservation of energy. Students calculate the potential energy of the pendulum and predict how fast it will travel knowing that the potential energy will convert into kinetic energy. They verify their predictions by measuring the speed of the pendulum.

Integrated Teaching And Learning Program

121

Potential and range of application of elastic backscatter lidar systems using polarization selection to minimize detected skylight noise  

Microsoft Academic Search

We examine the potential, range of application, and limiting factors of a polarization selection technique, recently devised by us, which takes advantage of naturally occurring polarization properties of scattered sky light to minimize the detected sky background signal and which can be used in conjunction with linearly polarized elastic backscatter lidars to maximize lidar receiver SNR. In this approach, a

S. A. Ahmed; Y. Y. Hassebo; B. Gross; M. Oo; F. Moshary

2006-01-01

122

Sensitivities of the proton-nucleus elastic scattering observables of {sup 6}He and {sup 8}He at intermediate energies  

SciTech Connect

We investigate the use of proton-nucleus elastic scattering experiments using secondary beams of {sup 6}He and {sup 8}He to determine the physical structure of these nuclei. The sensitivity of these experiments to nuclear structure is examined by using four different nuclear structure models with different spatial features using a full-folding optical potential model. The results show that elastic scattering at intermediate energies (<100 MeV per nucleon) is not a good constraint to be used to determine features of structure. Therefore researchers should look elsewhere to put constraints on the ground state wave function of the {sup 6}He and {sup 8}He nuclei. (c) 2000 The American Physical Society.

Weppner, S. P. [Natural Sciences, Eckerd College, St. Petersburg, Florida 33711 (United States); Garcia, Ofir [Natural Sciences, Eckerd College, St. Petersburg, Florida 33711 (United States); Elster, Ch. [Institute of Nuclear and Particle Physics, Ohio University, Athens, Ohio 45701 (United States)

2000-04-01

123

Low-energy {sup 3}He({alpha},{alpha}){sup 3}He elastic scattering and the {sup 3}He({alpha},{gamma}){sup 7}Be reaction  

SciTech Connect

The cross sections of the {sup 3}He({alpha},{alpha}){sup 3}He and {sup 3}He({alpha},{gamma}){sup 7}Be reactions are studied at low energies using a simple two-body model in combination with a double-folding potential. At very low energies the capture cross section is dominated by direct s-wave capture. However, at energies of several MeV the d-wave contribution increases, and the theoretical capture cross section depends sensitively on the strength of the L=2 potential. Whereas the description of the L=2 elastic phase shift requires a relatively weak potential strength, recently measured capture data can be described only with a significantly enhanced L=2 potential. A simultaneous description of the new experimental capture data and the elastic phase shifts is not possible within this model. Because of the dominating extranuclear capture, this conclusion holds in general for most theoretical models.

Mohr, Peter [Diakonie-Klinikum Schwaebisch Hall, D-74523 Schwaebisch Hall (Germany)

2009-06-15

124

Wind Energy: Progress and Potential  

Microsoft Academic Search

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

KAMIL KAYGUSUZ

2004-01-01

125

Energies of Screened Coulomb Potentials.  

ERIC Educational Resources Information Center

|This article shows that, by applying the Hellman-Feynman theorem alone to screened Coulomb potentials, the first four coefficients in the energy series in powers of the perturbation parameter can be obtained from the unperturbed Coulomb system. (Author/HM)|

Lai, C. S.

1979-01-01

126

Analysis of Potential Energy Surfaces.  

ERIC Educational Resources Information Center

|Introduces different methodological strategies in analyzing potential energy surfaces (PES) used in chemical reactivity studies. Discusses the theory of PES and gives examples to be used for student work. Provides procedures for calculating normal coordinates and vibrational properties of an activated complex. (ML)|

Fernandez, G. M.; And Others

1988-01-01

127

Tsunami earthquake generation by the release of gravitational potential energy  

NASA Astrophysics Data System (ADS)

Earthquakes that generate large tsunamis share a number of unusual features. They commonly have long source-time functions, involve large displacements, of 10 m or more, of the prisms of poorly consolidated sediment that form the accretionary wedge, and have many aftershocks with normal faulting mechanisms on the landward side of the trench. These features are not easily understood if the only source of the energy involved is the stored elastic strain. The observations, especially those from the Tohoku, Japan, 2011 earthquake, instead suggest that the observed behaviour results from the release of gravitational potential energy, as well as elastic strain. A simple model of this process can account for these and other observations.

McKenzie, Dan; Jackson, James

2012-09-01

128

Energy current imaging method for time reversal in elastic media  

SciTech Connect

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.

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

129

Elastic scattering of 11B from 209Bi in the energy range 49.8<=E<=84.1 MeV  

NASA Astrophysics Data System (ADS)

The elastic scattering of 11B from 209Bi has been measured at laboratory energies of 49.8, 51.3, 52.2, 52.8, 54.3, 55.8, 59.8, 64.8, 69.8, 74.8 and 84.1 MeV. These data have been analyzed using a microscopic optical model and the energy dependence of the real and the imaginary parts of the optical potential at near barrier energies has been determined. The ``threshold anomaly'' observed in the real part of the potential is found to be consistent with the dispersion relation which connects the real and the imaginary parts of the potential. Inelastic scattering and transfer reactions have also been measured at energies of 51.3, 55.8, 59.8 and 74.8 MeV. DWBA calculations for the 3- state in 209Bi are made. From the measured transfer probabilities, using a semiclassical approach the strength of the form factors have been obtained. The fusion cross sections have been derived at these energies from the corresponding quasi-elastic scattering angular distribution data. The fusion cross sections calculated using the energy dependent barriers extracted from the energy dependent real parts of the potential compare well with, that determined from quasi-elastic scattering data and are also in good agreement with simplified coupled channels calculation for fusion incorporating important inelastic and transfer channels.

Shrivastava, A.; Kailas, S.; Singh, P.; Chatterjee, A.; Navin, A.; Samant, A. M.; Ramdev Raj, V.; Mandal, S.; Datta, S. K.; Awasthi, D. K.

1998-06-01

130

Regge-Pole Model for pp and p¯p Elastic Scattering at High Energies  

Microsoft Academic Search

High-energy data for pp and p¯p elastic scattering are confronted with the simple Regge-pole model in an attempt to discover which features of these data, if any, are beyond the power of this model. The simplest representation, with only three poles (P, P', and omega), gives a reasonable fit to all the data except the \\

Donald M. Austin; William H. Greiman; William Rarita

1970-01-01

131

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

SciTech Connect

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.

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

1996-12-31

132

Proton-proton and proton-antiproton elastic scattering at high energies: Theory, phenomenology, and experiment.  

National Technical Information Service (NTIS)

This is a brief review of the progress in the understanding, during the past twenty years, of hadronic elastic scattering near the forward direction at high energies. On the basis of quantum gauge field theories, the Pomeron is found to be a branch cut ab...

T. T. Wu

1990-01-01

133

Calculation of elasticity and high pressure instabilities in corundum and stishovite with the Potential Induced Breathing Model  

NASA Astrophysics Data System (ADS)

Direct calculation of elasticity in the Potential Induced Breathing (PIB) model is developed. This allows calculation of elastic constants and acoustic velocities of oxides and silicates without any experimental data other than the values of fundamental constants, such as Planck’s constant. The PIB model allows for spherical charge relaxation in response to the long-range electrostatic potential. This feature is not present in any other lattice dynamical model, and leads to many-body forces that break the Cauchy conditions for centrosymmetric crystals (i.e. C44=C12) without the introduction of explicit angle bending forces. The elastic properties are calculated here for corundum and stishovite. High pressure elastic instabilities are found for both corundum (?-Al2O3) and stishovite (SiO2). Softening of C44 for corundum is calculated to begin at approximately 120 GPa. This may require reconsideration of the ruby fluorescence pressure scale and recent ultra-high pressure diamond cell experiments. The high pressure instability in stishovite leads to a low pressure dependence for the aggregate shear wave velocity.

Cohen, Ronald E.

1987-01-01

134

Energy functions for rubber from microscopic potentials  

Microsoft Academic Search

The finite deformation theory of rubber and related materials is based on energy functions that describe the macroscopic response of these materials under deformation. Energy functions and elastic constants are here derived from a simple microscopic (ball-and-spring) model. Exact uniaxial force-extension relationships are given for Hooke's Law and for the thermodynamic entropy-based microscopic model using the Gaussian and the inverse

A. S. Johal; D. J. Dunstan

2007-01-01

135

Elastic scattering of intermediate-energy electrons from C{sub 60} molecules  

SciTech Connect

Experimental and calculated differential cross sections for elastic scattering of electrons by C{sub 60} molecules at collision energies of 100 to 500 eV are reported. The elastic differential cross sections were measured in a standard crossed-beam apparatus, while the calculations were performed employing the Schwinger multichannel technique at the static-exchange level. Diffraction effects, some due to the overall spherical-cage structure and some to scattering by individual C atoms, are observed in both the measured and calculated cross sections.

Hargreaves, L. R.; Lohmann, B. [ARC Centre for Antimatter-Matter Studies, University of Adelaide, Adelaide, 5005 (Australia); Winstead, C.; McKoy, V. [A. A. Noyes Laboratory for Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States)

2010-12-15

136

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

PubMed

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

James, Richard; Fukuda, Jun-ichi

2013-07-08

137

A benchmark calculation for resonant electron-hydrogen elastic scattering at low energies  

SciTech Connect

Accurate differential cross sections (DCS) and spin-asymmetries for the elastic scattering of electrons from ground state hydrogen over the energies of the lowest {sup 1}S and {sup 3}P resonances have been obtained using the Intermediate R-matrix method of Odgers et al and the direct numerical approach of Wang and Callaway. The effects of ionization continuum on DCS, resonant positions, and spin-asymmetries are reexamined in light of the present calculations. The calculated elastic DCS are compared with the experiments of Williams and the calculation of McCarthy and Shang.

Wang, Y.D.; Lin, C.D.; Fon, W.C. [Univ. of Malaya (Malaysia); Odgers, B.R. [Queen`s Univ., Belfast (United Kingdom)

1996-05-01

138

A Benchmark Calculation for Resonant Electron-Hydrogen Elastic Scattering at Low Energies  

NASA Astrophysics Data System (ADS)

Accurate differential cross sections (DCS) and spin-asymmetries for the elastic scattering of electrons from ground state hydrogen over the energies of the lowest ^1S and ^3P resonances have been obtained using the Intermediate R-matrix method of Odgers et al and the direct numerical approach of Wang and Callaway. The effects of ionization continuum on DCS, resonant positions, and spin-asymmetries are reexamined in light of the present calculations. The calculated elastic DCS are compared with the experiments of Williams and the calculation of McCarthy and Shang.

Wang, Y. D.; Lin, C. D.; Fon, W. C.; Odgers, B. R.

1996-05-01

139

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

NASA Astrophysics Data System (ADS)

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.

James, Richard; Fukuda, Jun-ichi

2013-07-01

140

Coupled-channel effects in low-energy elastic pion scattering  

SciTech Connect

In pion-nucleus scattering near 50 MeV, the Coulomb and nuclear amplitudes are comparable for a fairly wide range of angles. The interference of these amplitudes makes small nuclear structure effects observable in elastic scattering. As a result, energy dependent optical model analyses of /sup 12/C do not reproduce the observed 50 MeV cross sections. Including the ground and first excited state of /sup 12/C in a coupled-channel calculation provides a consistent interpretation of both the elastic and inelastic data between 20 and 100 MeV.

Whisnant, C.S.

1986-04-01

141

The potential of renewable energy  

SciTech Connect

On June 27 and 28, 1989, the US Department of Energy (DOE) national laboratories were convened to discuss plans for the development of a National Energy Strategy (NES) and, in particular, the analytic needs in support of NES that could be addressed by the laboratories. As a result of that meeting, interlaboratory teams were formed to produce analytic white papers on key topics, and a lead laboratory was designated for each core laboratory team. The broad-ranging renewables assignment is summarized by the following issue statement from the Office of Policy, Planning and Analysis: to what extent can renewable energy technologies contribute to diversifying sources of energy supply What are the major barriers to greater renewable energy use and what is the potential timing of widespread commercialization for various categories of applications This report presents the results of the intensive activity initiated by the June 1989 meeting to produce a white paper on renewable energy. Scores of scientists, analysts, and engineers in the five core laboratories gave generously of their time over the past eight months to produce this document. Their generous, constructive efforts are hereby gratefully acknowledged. 126 refs., 44 figs., 32 tabs.

Not Available

1990-03-01

142

Low-energy nuclear reactions and the alpha-nucleus optical potential: where do we stand?  

Microsoft Academic Search

Recent efforts to develop an accurate and reliable alpha-nucleus optical potential at low energies are presented. In view of the advent of new data on alpha elastic scattering and alpha radiative-capture reactions, the global semi-microscopic alpha-nucleus potential is revisited and compared with the updated database. Needs for improvements are discussed.

P. Demetriou; M. Axiotis

2007-01-01

143

Global Optical Potential for {sup 6}He Interactions at Low Energies  

SciTech Connect

Within the framework of optical model, we present a set of global optical potential for the elastic scattering of {sup 6}He halo nucleus from different target nuclei ranging from {sup 12}C to {sup 209}Bi at low energies. Consistent agreement with the experimental data has been obtained by using this global potential.

Kucuk, Y.; Boztosun, I.; Topel, T. [Department of Physics, Erciyes University, Kayseri (Turkey)

2009-08-26

144

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

SciTech Connect

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.

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

145

An empirical many-body potential energy function constructed from pair-interactions  

Microsoft Academic Search

A new empirical potential energy function (PEF) is proposed, which is formed from pair-interactions only, and containes the many-body contributions. The PEF satisfies bulk cohesive energy and bulk stability condition. The PEF is parameterized for copper, silver, and gold elements in fcc crystal structure. The elastic constants C 11 and C 12 and the bulk modulus of the elements are

Ssakir Erkoç

1994-01-01

146

Proton-proton and proton-antiproton elastic scattering at high energies: Theory, phenomenology, and experiment  

SciTech Connect

This is a brief review of the progress in the understanding, during the past twenty years, of hadronic elastic scattering near the forward direction at high energies. On the basis of quantum gauge field theories, the Pomeron is found to be a branch cut above 1. Using the physical picture that this result implies, phenomenology for proton-proton and antiproton-proton elastic scattering is constructed. Two noteworthy features are that, at high energies, both the total cross section and the ratio of the integrated elastic cross section to the total cross section to the total cross section are increasing functions of the center-of-mass energy. Detailed predictions are given for the elastic differential cross sections, Coulomb interference and the ratios of the real to imaginary parts of the forward amplitudes. These predictions have been extensively and accurately confirmed by experiments, and have also been given both for future experiments on existing accelerators and for experiments on future accelerators. 14 refs., 2 figs.

Wu, Tai Tsun.

1990-01-01

147

Proton-proton and proton-antiproton elastic scattering at high energies: Theory, phenomenology, and experiment  

SciTech Connect

This is a brief review of the progress in the understanding, during the past twenty years, of hadronic elastic scattering near the forward direction at high energies. On the basis of quantum gauge field theories, the Pomeron is found to be a branch cut above 1. Using the physical picture that this result implies, phenomenology for proton-proton and antiproton-proton elastic scattering is constructed. Two noteworthy features are that, at high energies, both the total cross section and the ratio of the integrated elastic cross section to the total cross section to the total cross section are increasing functions of the center-of-mass energy. Detailed predictions are given for the elastic differential cross sections, Coulomb interference and the ratios of the real to imaginary parts of the forward amplitudes. These predictions have been extensively and accurately confirmed by experiments, and have also been given both for future experiments on existing accelerators and for experiments on future accelerators. 14 refs., 2 figs.

Wu, Tai Tsun

1990-12-31

148

Systematic investigation of three-nucleon force effects in elastic scattering of polarized protons from deuterons at intermediate energies  

SciTech Connect

The question, whether the high-quality nucleon-nucleon potentials can successfully describe the three-nucleon system, and to what extent three-nucleon forces (3NFs) play a role, has become very important in nuclear few-body physics. One kinematic region where effects because of 3NFs show up is in the minimum of the differential cross section of elastic nucleon-deuteron scattering. Another observable, which could give an indication about the contribution of the spin to 3NFs, is the vector analyzing power. To investigate the importance of 3NFs systematically over a broad range of intermediate energies, both observables of elastic proton-deuteron scattering have been measured at proton bombarding energies of 108, 120, 135, 150, 170, and 190 MeV, covering an angular range in the center-of-mass system between 30 deg. and 170 deg. The results show unambiguously the shortcomings of calculations employing only two-body forces and the necessity of the inclusion of 3NFs. They also show the limitations of the results of the present day models for few-nucleon systems at backward angles, especially at higher beam energies. New calculations based on chiral perturbation theory are also presented and compared with the data at the lowest energy.

Ermisch, K.; Amir-Ahmadi, H.R.; Berg, A.M. van den; Castelijns, R.; Davids, B.; Harakeh, M.N.; Hunyadi, M.; Huu, M.A. de; Kalantar-Nayestanaki, N.; Kis, M.; Mahjour-Shafiei, M.; Woertche, H.J. [Kernfysisch Versneller Instituut (KVI), Groningen (Netherlands); Deltuva, A.; Sauer, P.U. [Institut fuer Theoretische Physik, Universitaet Hannover (Germany); Epelbaum, E. [Thomas Jefferson National Accelerator Laboratory, Newport News, Virginia 23606 (United States); Gloeckle, W. [Institut fuer Theoretische Physik II, Universitaet Bochum (Germany); Golak, J.; Skibinski, R.; Witala, H. [Institute of Physics, Jagellonian University, Cracow (Poland); Kamada, H. [Department of Physics, Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu (Japan)] [and others

2005-06-01

149

Elastic electron scattering from rare gases with exact exchange: a new correlation-polarisation potential  

Microsoft Academic Search

Summary  The many-body correlation forces which act between the impinging electron and the bound electrons of the target atoms are\\u000a treated here using a newly developed correlation-polarisation potential that originates from the calculation of correlation\\u000a energies in electronic bound states of atoms and molecules. The new formulation of such forces is shown to be particularly\\u000a effective for the present systems once

F. A. Gianturco; J. A. Rodriguez-Ruiz

1994-01-01

150

On dual conservation laws in planar elasticity  

Microsoft Academic Search

Dual conservation laws of linear planar elasticity theory have been systematically studied based on stress function formalism. By employing generalized symmetry transformation or Lie–Bäcklund transformation, a class of new dual conservation laws in planar elasticity have been discovered based on Noether theorem and its Bessel–Hagen generalization. These dual conservation laws represent variational symmetry properties of complementary potential energy, which stems

Shaofan Li

2004-01-01

151

Consistent finite element procedures for nonlinear rubber elasticity with a higher order strain energy function  

NASA Astrophysics Data System (ADS)

The use of higher order terms in the Rivlin's polynomial strain energy density function is necessary to describe the elastic behavior of rubber undergoing very large and complex deformation. In this paper, the material response tensor for general Rivlin's strain energy density function is derived in a consistent manner such that both major and minor symmetries are retained. Lack of minor symmetry in the material response tensor will lead to numerical convergence difficulties, especially in shear dominant problems. The projection method is used to avoid volumetric locking due to the nearly incompressible nature of rubber. The relation between the numerical penalty number and the material bulk modulus is characterized. The importance of this relation is demonstrated in the study of the apparent Young's modulus of bonded rubber units. The need to include higher order terms in the strain energy density function is presented in the numerical examples. Several classical elasticity problems are also analyzed.

Chen, J. S.; Satyamurthy, K.; Hirschfelt, L. R.

1994-03-01

152

Elastic electron scattering in krypton in the energy range from 5 to 10 eV  

SciTech Connect

Differential cross sections for elastic electron scattering in krypton have been measured at the energies of 5,7.5, and 10 eV over the scattering angle range from 30 deg. to 180 deg. The measurements for backward scattering employed the magnetic angle-changing technique. These differential cross sections have been integrated to yield the elastic integral and momentum transfer cross sections at the above energies. These new results are compared with the most recent measurements and calculations of the respective cross sections in krypton. The dependence of the differential cross sections on atomic polarizability of the heavier rare gas atoms argon, krypton, and xenon has also been investigated over the electron energy range 5-30 eV and for forward, backward, and intermediate scattering angles.

Linert, Ireneusz; Mielewska, Brygida; Zubek, Mariusz [Department of Physics of Electronic Phenomena, Gdansk University of Technology, 80-233 Gdansk (Poland); King, George C. [School of Physics and Astronomy, Manchester University, Manchester M13 9 PL (United Kingdom)

2010-01-15

153

Aspects of energy propagation in highly anisotropic elastic solids  

Microsoft Academic Search

Summary Anomalies in the theory of wave propagation in constrained materials may be reconciled with the standard theory of wave propagation in unconstrained materials by relaxing the constraint slightly and then taking the limit as the constraint is obeyed exactly. In this paper the same method is employed in an attempt to reconcile anomalies in the propagation of energy in

G. A. Rogerson; N. H. Scott

1992-01-01

154

Optical potentials for the elastic scattering of /sup 6/Li+/sup 12/C, /sup 6/Li+/sup 16/O, and /sup 7/Li+/sup 12/C  

SciTech Connect

New elastic scattering angular distributions extending over the large angular range 10/sup 0/--170/sup 0/ c.m. are reported for /sup 6/Li+/sup 12/C at 24 and 30 MeV, /sup 6/Li+/sup 16/O at 25.7 MeV, and /sup 7/Li+/sup 12/C at 34 MeV. These data have been analyzed and are well described by the optical model using Woods-Saxon potentials, or by potentials with a double-folded real part. Using these and previously published data, average energy-dependent potentials have been obtained. Improved descriptions of the elastic scattering of /sup 6/Li+/sup 12/C, /sup 6/Li+/sup 16/O, and /sup 7/Li+/sup 12/C for energies from the Coulomb barrier up to 26 MeV/nucleon are obtained with these new average potentials compared with existing ones.

Vineyard, M.F.; Cook, J.; Kemper, K.W.; Stephens, M.N.

1984-09-01

155

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

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.

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

1981-01-15

156

Elastic scattering of polarized deuterons by protons at intermediate energies  

Microsoft Academic Search

The tensor analyzing power T20(theta) in dp backward scattering has been measured at or near center-of-mass angle theta = 180° in the energy range 0.3-2.3 GeV. A pronounced structure is observed around Td = 0.5 GeV which is explained by a predominant one-neutron-exchange mechanism. Other structures appear around 1 GeV and higher. They are not explained by calculations which include

J. Arvieux; S. D. Baker; R. Beurtey; M. Boivin; J. M. Cameron; T. Hasegawa; D. Hutcheon; J. Banaigs; J. Berger; A. Codino; J. Duflo; L. Goldzahl; F. Plouin; A. Boudard; G. Gaillard; Nguyen van Sen; Ch. F. Perdrisat

1984-01-01

157

Potential energy surface of cyclooctatetraene  

NASA Astrophysics Data System (ADS)

We present a theoretical study of the cyclooctatetraene (COT) molecule. Seven COT structures are located on the singlet ground state potential energy surface. Four of them, which present D2d (tub), Cs (bicyclo[4.2.0]octa-2,4,7-triene or BOT), C2h (chair) and D4 (crown) symmetries are stable species, and the other three are transition state structures showing Cs, D4h, and D8h symmetry. We discuss the symmetry of wave functions for these stationary points. Geometries, energies, and harmonic vibrational frequencies of these structures, and energy gaps between singlet-triplet states and low-lying singlets are presented. For the planar D4h and D8h structures, Jahn-Teller and tunneling effects have also been discussed. Ring inversion, bond shifting and valence isomerization reactive channels from the tub COT conformer are discussed from the point of view of the corresponding transition state structures. Where possible, in order to lend support to this theoretical information comparisons with recent transition state spectroscopy data are made.

Andrés, José L.; Castaño, Obis; Morreale, Antonio; Palmeiro, Raul; Gomperts, Roberto

1998-01-01

158

Unified interatomic potential and energy barrier distributions for amorphous oxides  

NASA Astrophysics Data System (ADS)

Amorphous tantala, titania, and hafnia are important oxides for biomedical implants, optics, and gate insulators. Understanding the effects of oxide doping is crucial to optimize performance in these applications. However, no molecular dynamics potentials have been created to date that combine these and other oxides that would allow computational analyses of doping-dependent structural and mechanical properties. We report a novel set of computationally efficient, two-body potentials modeling van der Waals and covalent interactions that reproduce the structural and elastic properties of both pure and doped amorphous oxides. In addition, we demonstrate that the potential accurately produces energy barrier distributions for pure and doped samples. The distributions can be directly compared to experiment and used to calculate physical quantities such as internal friction to understand how doping affects material properties. Future analyses using these potentials will be of great value to determine optimal doping concentrations and material combinations for myriad material science applications.

Trinastic, J. P.; Hamdan, R.; Wu, Y.; Zhang, L.; Cheng, Hai-Ping

2013-10-01

159

Unified interatomic potential and energy barrier distributions for amorphous oxides.  

PubMed

Amorphous tantala, titania, and hafnia are important oxides for biomedical implants, optics, and gate insulators. Understanding the effects of oxide doping is crucial to optimize performance in these applications. However, no molecular dynamics potentials have been created to date that combine these and other oxides that would allow computational analyses of doping-dependent structural and mechanical properties. We report a novel set of computationally efficient, two-body potentials modeling van der Waals and covalent interactions that reproduce the structural and elastic properties of both pure and doped amorphous oxides. In addition, we demonstrate that the potential accurately produces energy barrier distributions for pure and doped samples. The distributions can be directly compared to experiment and used to calculate physical quantities such as internal friction to understand how doping affects material properties. Future analyses using these potentials will be of great value to determine optimal doping concentrations and material combinations for myriad material science applications. PMID:24160526

Trinastic, J P; Hamdan, R; Wu, Y; Zhang, L; Cheng, Hai-Ping

2013-10-21

160

Pion elastic scattering from polarized 13C in the energy region of the P33 resonance  

NASA Astrophysics Data System (ADS)

Analyzing powers Ay were measured for ?+ and ?- elastic scattering from polarized 13C at incident pion energies T? near the P33 ?-nucleon resonance. At T?=130 MeV, the values of Ay are significantly different from zero for ?- scattering. For ?+ at T?=130 MeV and for both ?- and ?+ at all other energies, the Ay are mostly consistent with zero. Elastic differential cross sections were measured using an unpolarized 13C target. Both the analyzing-power and cross-section data were compared with predictions using a variety of nuclear structure and reaction models. The analyzing power was found to be strongly sensitive to the quadrupole spin-flip part of the transition. The data of this work complement measurements of the magnetic form factor by electron scattering. The pion Ay data are not reproduced by calculations using wave functions that fit the magnetic form factor at low momentum transfers.

Yen, Yi-Fen; Brinkmöller, B.; Dehnhard, D.; Franey, M. A.; Sterbenz, S. M.; Yu, Yi-Ju; Berman, Brian; Burleson, G. R.; Cranston, K.; Klein, A.; Kyle, G. S.; Alarcon, R.; Averett, T.; Comfort, J. R.; Görgen, J. J.; Ritchie, B. G.; Tinsley, J. R.; Barlett, M.; Hoffmann, G. W.; Johnson, K.; Moore, C. F.; Purcell, M.; Ward, H.; Williams, A.; Faucett, J. A.; Greene, S. J.; Jarmer, J. J.; McGill, J. A.; Morris, C. L.; Penttilä, S. I.; Tanaka, N.; Fortune, H. T.; Insko, E.; Ivie, R.; O'donnell, J. M.; Smith, D.; Khandaker, M. A.; Chakravarti, S.

1994-08-01

161

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

SciTech Connect

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.

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

162

An energy absorbing far-field boundary condition for the elastic wave equation  

SciTech Connect

The authors present an energy absorbing non-reflecting boundary condition of Clayton-Engquist type for the elastic wave equation together with a discretization which is stable for any ratio of compressional to shear wave speed. They prove stability for a second order accurate finite-difference discretization of the elastic wave equation in three space dimensions together with a discretization of the proposed non-reflecting boundary condition. The stability proof is based on a discrete energy estimate and is valid for heterogeneous materials. The proof includes all six boundaries of the computational domain where special discretizations are needed at the edges and corners. The stability proof holds also when a free surface boundary condition is imposed on some sides of the computational domain.

Petersson, N A; Sjogreen, B

2008-07-15

163

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

SciTech Connect

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.

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

2000-04-04

164

Elastic scattering for the system 11 Be + 209 Bi at Coulomb barrier energies  

Microsoft Academic Search

.  The elastic scattering process for 11Be ions impinging on \\u000a a 209Bi target was studied in the energy range around the \\u000a Coulomb barrier. The angular distributions of the 11Be scattered \\u000a particles were analyzed within the optical model framework in order \\u000a to evaluate the reaction cross section, which turned out to be much larger\\u000a than the fusion one, especially in the sub-barrier

M. Mazzocco; C. Signorini; M. Romoli; R. Bonetti; A. De Francesco; A. De Rosa; M. Di Pietro; L. Fortunato; T. Glodariu; A. Guglielmetti; G. Inglima; T. Ishikawa; H. Ishiyama; R. Kanungo; N. Khai; S. Jeong; M. La Commara; B. Martin; H. Miyatake; T. Motobayashi; T. Nomura; D. Pierroutsakou; M. Sandoli; F. Soramel; L. Stroe; I. Sugai; M. H. Tanaka; E. Vardaci; Y. Watanabe; A. Yoshida; K. Yoshida

2007-01-01

165

Shadow model for the high-energy pion-proton elastic backward peak  

Microsoft Academic Search

Summary  We propose a model in which the elastic backward peak for high-energy pion-nucleon scattering is explained as the shadow of\\u000a the production processes. The small height of the backward peak as compared to that of the forward one is due to the forward-backward\\u000a asymmetries in the angular distributions of the secondaries in ?p collisions. The application of the model to

L. Bertocchi; A. Capella

1966-01-01

166

Heuristic search for a predictive strain-energy function in nonlinear elasticity  

Microsoft Academic Search

In this work, a new, quasi-structural model – bootstrapped eight-chain model – is proposed as a modification to the strain energy of eight-chain model [Arruda, E.M., Boyce, M.C., 1993. A three-dimensional constitutive model for the large stretch behaviour of rubber elastic materials. J. Mech. Phys. Solids 41, 389—412] that invokes the Langevin chain statistics. This development has been led to

Dmitri Miroshnychenko; W. A. Green

2009-01-01

167

Detailed Study for 16O Elastically Scattered from 16O at Energies 20, 24 and 28 MeV  

NASA Astrophysics Data System (ADS)

This paper includes the experimental measurements for the angular distributions of 16O ion beam elastically scattered by 16O nuclei at energies 20, 24 and 28 MeV. The experimental results were analyzed within the framework of both the optical model using different complex potential and the double folding (DF) potential obtained with different density-dependent nucleon-nucleon interactions which give the corresponding values of the nuclear incompressibility K in the Hartree-Fock calculation of nuclear matter. The agreement between the experimental results and the theoretical predictions in the whole angular range is fairly good. In DF calculations, the obtained normalization coefficient Nr is in the range 0.833-1.07.

Hamada, Sh.; Burtebayev, N.; Amangeldi, N.

2013-08-01

168

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

PubMed

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(-1) (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(-1) and 1.7 MJ kg(-1), or 476 W h kg(-1), larger than a Li-ion battery and is environmentally friendly. PMID:24126736

Peng, Qing; De, Suvranu

2013-10-23

169

Elastic Strain Energy Storage and Neighboring Organ Assistance for Fluid Propulsion  

NASA Astrophysics Data System (ADS)

Storage of elastic strain energy by non-muscular structures such as tendons and ligaments, is a common scheme employed by jumping animals. Also, since skeletal muscle is attached to bone, mechanical advantage is obtained, allowing a burst of power that is unobtainable by muscle contraction alone. This is important at launch since force may be applied for only the brief period when the legs are in contact with the ground. Liquid propelling structures such as the urinary bladder and the heart face the similar problem of being able to impart force to the content only as long as the wall is in a stretched state. Using data from videocystometry and cardiac catheterisation we show that the means employed to achieve liquid propulsion appears to involve a combination of isometric contraction (contraction against a closed sphincter or valve) with hyperelastic stretch of the wall, elastic strain energy storage by the wall, overshoot past the undistended state and neighboring organ assistance (NOA). Thus, the heart, a partially collapsible thick muscular shell without the benefit of NOA manages an ejection fraction of about 70%. Using all of the above means, the collapsible urinary bladder is able to nearly always empty. Elastic strain energy storage and NOA appear to be important strategies for liquid propulsion employed by hollow viscera.

Arun, C. P.

2003-11-01

170

Elastic resistance change and action potential generation of non-faradaic Pt/TiO2/Pt capacitors  

NASA Astrophysics Data System (ADS)

Electric current in the mixed ionic-electronic conductor TiO2 is hysteretic, i.e. history-dependent, and its use is versatile in electronic devices. Nowadays, biologically inspired, analogue-type computing systems, known as neuromorphic systems, are being actively investigated owing to their new and intriguing physical concepts. The realization of artificial synapses is important for constructing neuromorphic systems. In mammalians' brains, the plasticity of synapses between neighbouring nerve cells arises from action potential firing. Emulating action potential firing via inorganic systems has therefore become important in neuromorphic engineering. In this work, the current-voltage hysteresis of TiO2-based non-faradaic capacitors is investigated to primarily focus on the correlation between the blocking contact and the elasticity, i.e. non-plasticity, of the capacitors' resistance change, in experimental and theoretical methods. The similarity between the action potential firing behaviour in nerve cells and the elasticity of the non-faradaic capacitors is addressed.Electric current in the mixed ionic-electronic conductor TiO2 is hysteretic, i.e. history-dependent, and its use is versatile in electronic devices. Nowadays, biologically inspired, analogue-type computing systems, known as neuromorphic systems, are being actively investigated owing to their new and intriguing physical concepts. The realization of artificial synapses is important for constructing neuromorphic systems. In mammalians' brains, the plasticity of synapses between neighbouring nerve cells arises from action potential firing. Emulating action potential firing via inorganic systems has therefore become important in neuromorphic engineering. In this work, the current-voltage hysteresis of TiO2-based non-faradaic capacitors is investigated to primarily focus on the correlation between the blocking contact and the elasticity, i.e. non-plasticity, of the capacitors' resistance change, in experimental and theoretical methods. The similarity between the action potential firing behaviour in nerve cells and the elasticity of the non-faradaic capacitors is addressed. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr02154h

Lim, Hyungkwang; Jang, Ho Won; Lee, Doh-Kwon; Kim, Inho; Hwang, Cheol Seong; Jeong, Doo Seok

2013-06-01

171

General solution for transversely isotropic magneto-electro-thermo-elasticity and the potential theory method  

Microsoft Academic Search

The three-dimensional equations of transversely isotropic magneto-electro-thermo-elasticity are simplified by the introduction of two displacement functions. A general solution is then rigorously derived by virtue of the operator theory, which is expressed in terms of two functions, satisfying a second-order and a tenth-order homogeneous partial differential equation, respectively. Utilizing the generalized Almansi's theorem, the general solution can be further simplified

W. Q Chen; Kang Yong Lee; H. J Ding

2004-01-01

172

California's Biomass and Its Energy Potential.  

National Technical Information Service (NTIS)

The potentials for using California's biomass for energy have been assessed. The study relies on the recent work of Amory Lovins and Lawrence Berkeley Laboratory's (LBL) Distributed Energy System's Project to specify an energy future for Californians. The...

F. B. Lucarelli

1980-01-01

173

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

SciTech Connect

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.

Nguyen, Ba Nghiep; Paquette, Joshua

2010-08-01

174

Temperature dependence of lysozyme hydration and the role of elastic energy.  

PubMed

Water plays a critical role in protein dynamics and functions. However, the most basic property of hydration--the water sorption isotherm--remains inadequately understood. Surface adsorption is the commonly adopted picture of hydration. Since it does not account for changes in the conformational entropy of proteins, it is difficult to explain why protein dynamics and activity change upon hydration. The solution picture of hydration provides an alternative approach to describe the thermodynamics of hydration. Here, the flexibility of proteins could influence the hydration level through the change of elastic energy upon hydration. Using nuclear magnetic resonance to measure the isotherms of lysozyme in situ between 18 and 2 °C, the present work provides evidence that the part of water uptake associated with the onset of protein function is significantly reduced below 8 °C. Quantitative analysis shows that such reduction is directly related to the reduction of protein flexibility and enhanced cost in elastic energy upon hydration at lower temperature. The elastic property derived from the water isotherm agrees with direct mechanical measurements, providing independent support for the solution model. This result also implies that water adsorption at charged and polar groups occurring at low vapor pressure, which is known for softening the protein, is crucial for the later stage of water uptake, leading to the activation of protein dynamics. The present work sheds light on the mutual influence of protein flexibility and hydration, providing the basis for understanding the role of hydration on protein dynamics. PMID:21517540

Wang, Hai-Jing; Kleinhammes, Alfred; Tang, Pei; Xu, Yan; Wu, Yue

2011-03-31

175

Muscle-tendon interaction and elastic energy usage in human walking.  

PubMed

The present study was designed to explore how the interaction between the fascicles and tendinous tissues is involved in storage and utilization of elastic energy during human walking. Eight male subjects walked with a natural cadence (1.4 +/- 0.1 m/s) on a 10-m-long force plate system. In vivo techniques were employed to record the Achilles tendon force and to scan real-time fascicle lengths for two muscles (medial gastrocnemius and soleus). The results showed that tendinous tissues of both medial gastrocnemius and soleus muscles lengthened slowly throughout the single-stance phase and then recoiled rapidly close to the end of the ground contact. However, the fascicle length changes demonstrated different patterns and amplitudes between two muscles. The medial gastrocnemius fascicles were stretched during the early single-stance phase and then remained isometrically during the late-stance phase. In contrast, the soleus fascicles were lengthened until the end of the single-stance phase. These findings suggest that the elastic recoil takes place not as a spring-like bouncing but as a catapult action in natural human walking. The interaction between the muscle fascicles and tendinous tissues plays an important role in the process of release of elastic energy, although the leg muscles, which are commonly accepted as synergists, do not have similar mechanical behavior of fascicles in this catapult action. PMID:15845776

Ishikawa, Masaki; Komi, Paavo V; Grey, Michael J; Lepola, Vesa; Bruggemann, Gert-Peter

2005-04-21

176

Adhesion energy of receptor-mediated interaction measured by elastic deformation.  

PubMed Central

We investigated the role of receptor binding affinity in surface adhesion. A sensitive technique was developed to measure the surface energy of receptor-mediated adhesion. The experimental system involved a functionalized elastic agarose bead resting on a functionalized glass coverslip. Attractive intersurface forces pulled the two surfaces together, deforming the bead to produce an enlarged contact area. The Johnson-Kendall-Roberts (JKR) model was used to relate the surface energy of the interaction to the elasticity of the bead and the area of contact. The surface energies for different combinations of modified surfaces in solution were obtained from reflection interference contrast microscopy (RICM) measurements of the contact area formed by the bead and the coverslip. Studies with surfaces functionalized with ligand-receptor pairs showed that the relationship between surface energy and the association constant of the ligand binding has two regimes. At low binding affinity, surface energy increased linearly with the association constant, while surface energy increased logarithmically with the association constant in the high affinity regime.

Moy, V T; Jiao, Y; Hillmann, T; Lehmann, H; Sano, T

1999-01-01

177

Proton optical potential and scattering matrix for tin nuclei at sub-Coulomb energies  

Microsoft Academic Search

A unified set of parameters of the proton optical potential is sought for tin nuclei at energies below the Coulomb barrier which gives a good description of the set of experimental data on the total cross sections for the pn reaction and the angular distributions of elastically scattered protons for E\\/sub p\\/< or = 10 MeV and which gives reliable

B. Y. Guzhovskii; B. M. Dzyuba

1981-01-01

178

Size-dependent reversal of the elastic interaction energy between misfit nanostructures.  

PubMed

By exploiting a fully three-dimensional finite-element modeling of strain fields, we investigate the spatial dependence of the elastic interaction energy between misfitting nanostructures beyond the point-dipole approximation. When interacting islands are finite in size, the detailed shape of the elastic strain field around and under the islands may convert the repulsive interactions, usually experienced between equal-sized islands, into an attractive basin between a large island and a population of neighboring clusters smaller than a critical size. The results of the simulations applied to large Ge islands grown on a Si(111) substrate have significant implications for the understanding of the strain-mediated coarsening of quantum dots around the islands. PMID:23327904

Persichetti, L; Sgarlata, A; Fanfoni, M; Balzarotti, A

2013-01-17

179

LETTER TO THE EDITOR: A benchmark calculation for resonant electron - hydrogen elastic scattering at low energies  

NASA Astrophysics Data System (ADS)

Two independent calculations have been carried out to obtain accurate differential cross sections (DCS) and spin asymmetries for the elastic scattering of electrons from ground-state hydrogen over the energies of the lowest 0953-4075/29/2/005/img6 and 0953-4075/29/2/005/img7 resonances. They use the IERM method and the direct numerical approach of Wang and Callaway. The effects of the ionization continuum on DCS, resonant positions, and spin asymmetries are re-examined in light of the present calculations. The calculated elastic DCS are compared with the experiments of Williams and the calculation of McCarthy and Shang. A benchmark calculation for the phaseshifts has been tabulated to assist future experimental normalization procedures.

Wang, Y. D.; Fon, W. C.; Lin, C. D.

1996-01-01

180

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

PubMed Central

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.

Fernandez-Sierra, Monica; Delgado-Marti, Violeta; Colon-Garcia, Jorge E.; Quinones, Edwin

2011-01-01

181

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

PubMed

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

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

2011-05-26

182

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

NASA Astrophysics Data System (ADS)

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 min. Using hydrodynamic equations we estimate the torque exerted on the dumbbells by the DNA braids, yielding values ranging from 47 to 166 pN nm.

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

2011-05-01

183

Repulsive nature of optical potentials for high-energy heavy-ion scattering  

SciTech Connect

The recent works by the present authors predicted that the real part of heavy-ion optical potentials changes its character from attraction to repulsion around the incident energy per nucleon E/A=200-300 MeV on the basis of the complex G-matrix interaction and the double-folding model (DFM) and revealed that the three-body force plays an important role there. In the present paper, we have precisely analyzed the energy dependence of the calculated DFM potentials and its relation to the elastic-scattering angular distributions in detail in the case of the {sup 12}C+{sup 12}C system in the energy range of E/A=100-400 MeV. The tensor force contributes substantially to the energy dependence of the real part of the DFM potentials and plays an important role to lower the attractive-to-repulsive transition energy. The nearside and farside (N/F) decompositions of the elastic-scattering amplitudes clarify the close relation between the attractive-to-repulsive transition of the potentials and the characteristic evolution of the calculated angular distributions with the increase of the incident energy. Based on the present analysis, we propose experimental measurements for the predicted strong diffraction phenomena of the elastic-scattering angular distribution caused by the N/F interference around the attractive-to-repulsive transition energy together with the reduced diffractions below and above the transition energy.

Furumoto, T.; Sakuragi, Y.; Yamamoto, Y. [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan) and RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Department of Physics, Osaka City University, Osaka 558-8585 (Japan) and RIKEN Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan); Physics Section, Tsuru University, Tsuru, Yamanashi 402-8555 (Japan)

2010-10-15

184

Elastic resistance change and action potential generation of non-faradaic Pt/TiO2/Pt capacitors.  

PubMed

Electric current in the mixed ionic-electronic conductor TiO2 is hysteretic, i.e. history-dependent, and its use is versatile in electronic devices. Nowadays, biologically inspired, analogue-type computing systems, known as neuromorphic systems, are being actively investigated owing to their new and intriguing physical concepts. The realization of artificial synapses is important for constructing neuromorphic systems. In mammalians' brains, the plasticity of synapses between neighbouring nerve cells arises from action potential firing. Emulating action potential firing via inorganic systems has therefore become important in neuromorphic engineering. In this work, the current-voltage hysteresis of TiO2-based non-faradaic capacitors is investigated to primarily focus on the correlation between the blocking contact and the elasticity, i.e. non-plasticity, of the capacitors' resistance change, in experimental and theoretical methods. The similarity between the action potential firing behaviour in nerve cells and the elasticity of the non-faradaic capacitors is addressed. PMID:23733132

Lim, Hyungkwang; Jang, Ho Won; Lee, Doh-Kwon; Kim, Inho; Hwang, Cheol Seong; Jeong, Doo Seok

2013-06-04

185

Simultaneous optical model analysis of elastic scattering, fusion, and breakup for the {sup 9}Be+{sup 144}Sm system at near-barrier energies  

SciTech Connect

A simultaneous optical model calculation of elastic scattering, complete fusion, and breakup cross sections for energies around the Coulomb barrier is presented for reactions involving the weakly bound projectile {sup 9}Be on the medium size target {sup 144}Sm. In the calculations, the nuclear polarization potential U is split into a volume part U{sub F}, which is responsible for fusion reactions, and a surface part U{sub DR}, which accounts for direct reactions. A simultaneous {chi}{sup 2} analysis of elastic and complete fusion data shows that the extracted optical potential parameters of the real V{sub F} and imaginary W{sub F} parts of U{sub F} and the corresponding parts V{sub DR} and W{sub DR} of U{sub DR} satisfy separately the dispersion relation. Energy-dependent forms for the fusion and direct reaction potentials indicate that, at the strong absorption radius, the direct reaction potentials dominate over the fusion potentials. Moreover, the imaginary direct reaction potential results in a rather smooth function of E around the barrier energy. These findings show that the threshold anomaly, usually present in reactions with tightly bound projectiles, is not exhibited for the system {sup 9}Be+{sup 144}Sm. Within this formalism, the effect of breakup reactions on complete fusion is studied by turning on and off the potentials responsible for breakup reactions.

Gomez Camacho, A.; Gomes, P. R. S.; Lubian, J.; Padron, I. [Departamento del Acelerador, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, C. P. 11801, Mexico D. F. Centro (Mexico); Instituto de Fisica, Universidade Federal Fluminenese, Avenida Litoranea s/n, Gragoata, Niteroi, RJ 24210-340 (Brazil); Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, Playa, Ciudad de la Habana (Cuba)

2008-05-15

186

Biomass energy potential in Turkey  

Microsoft Academic Search

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

K. Kaygusuz; M. F. Türker

2002-01-01

187

Energy functions for rubber from microscopic potentials  

NASA Astrophysics Data System (ADS)

The finite deformation theory of rubber and related materials is based on energy functions that describe the macroscopic response of these materials under deformation. Energy functions and elastic constants are here derived from a simple microscopic (ball-and-spring) model. Exact uniaxial force-extension relationships are given for Hooke's Law and for the thermodynamic entropy-based microscopic model using the Gaussian and the inverse Langevin statistical approximations. Methods are given for finding the energy functions as expansions of tensor invariants of deformation, with exact solutions for functions that can be expressed as expansions in even powers of the extension. Comparison with experiment shows good agreement with the neo-Hookean energy function and we show how this derives directly from the simple Gaussian statistical model with a small modification.

Johal, A. S.; Dunstan, D. J.

2007-04-01

188

The Available Potential Energy of Storms  

Microsoft Academic Search

The storm's available potential energy and its rate of change are derived for a vertically walled volume encircling the storm and extending from the surface to the top of the atmosphere. The rate of change includes explicit expressions for the generation of the storm's available potential energy, for its conversion to kinetic energy, and for its change through boundary work

Donald R. Johnson

1970-01-01

189

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

SciTech Connect

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.

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

1995-12-31

190

Muscle mechanical work and elastic energy utilization during walking and running near the preferred gait transition speed  

Microsoft Academic Search

Mechanical and metabolic energy conservation is considered to be a defining characteristic in many common motor tasks. During human gait, the storage and return of elastic energy in compliant structures is an important energy saving mechanism that may reduce the necessary muscle fiber work and be an important determinant of the preferred gait mode (i.e., walk or run) at a

Kotaro Sasaki; Richard R. Neptune

2006-01-01

191

Unitarity bounds and elastic hadron-hadron scattering in the energy region of the Superconducting Super Collider and beyond  

SciTech Connect

The possibility of saturation of unitarity bounds for elastic hadron-hadron scattering at very high energies is discussed with respect to two limits: the MacDowell-Martin and the uniform-disk bounds. The unitarity properties of these two bounds are shown. The analysis by the generalized geometrical scaling model suggests that [ital [bar p]p] elastic scattering first tends to the MacDowell-Martin bound and then turns to the uniform-disk bound as the elasticity becomes larger than [similar to]0.4.

Kawasaki, M. (Physics Department, Gifu University, Yanagido, Gifu 501-11 (Japan)); Maehara, T. (Faculty of School Education, Hiroshima University, Hiroshima 734 (Japan)); Yonezawa, M. (Department of Physics, Hiroshima University, Higashi-Hiroshima 724 (Japan))

1993-11-01

192

Dynamics and the free-energy landscape of proteins, explored with the mössbauer effect and quasi-elastic neutron scattering.  

PubMed

The Mössbauer effect and quasi-elastic neutron scattering (QENS) from hydrated proteins yield sharp elastic lines that are accompanied by broad wings. Conventionally, the elastic line and the broad wings are treated as separate phenomena. We show that there is no separation; the entire spectrum consists of Lorentzians with the natural line width. In protein crystals, the shifts of the individual lines from the elastic center above about 150 K are caused by beta fluctuations in the hydration shell. Vibrations cause shifts in the entire temperature range but are best seen below about 150 K. We construct a microscopic model for the dynamics that is based on a random walk of the proteins in their free-energy landscape. The model yields approximate values for the steps in the energy landscape. Remarkably, the quantum electrodynamic concept of gamma rays is needed to justify the model. PMID:23962200

Frauenfelder, Hans; Young, Robert D; Fenimore, Paul W

2013-09-12

193

Relationship between muscle forces, joint loading and utilization of elastic strain energy in equine locomotion.  

PubMed

Storage and utilization of strain energy in the elastic tissues of the distal forelimb of the horse is thought to contribute to the excellent locomotory efficiency of the animal. However, the structures that facilitate elastic energy storage may also be exposed to dangerously high forces, especially at the fastest galloping speeds. In the present study, experimental gait data were combined with a musculoskeletal model of the distal forelimb of the horse to determine muscle and joint contact loading and muscle-tendon work during the stance phase of walking, trotting and galloping. The flexor tendons spanning the metacarpophalangeal (MCP) joint - specifically, the superficial digital flexor (SDF), interosseus muscle (IM) and deep digital flexor (DDF) - experienced the highest forces. Peak forces normalized to body mass for the SDF were 7.3±2.1, 14.0±2.5 and 16.7±1.1 N kg(-1) in walking, trotting and galloping, respectively. The contact forces transmitted by the MCP joint were higher than those acting at any other joint in the distal forelimb, reaching 20.6±2.8, 40.6±5.6 and 45.9±0.9 N kg(-1) in walking, trotting and galloping, respectively. The tendons of the distal forelimb (primarily SDF and IM) contributed between 69 and 90% of the total work done by the muscles and tendons, depending on the type of gait. The tendons and joints that facilitate storage of elastic strain energy in the distal forelimb also experienced the highest loads, which may explain the high frequency of injuries observed at these sites. PMID:21075941

Harrison, Simon M; Whitton, R Chris; Kawcak, Chris E; Stover, Susan M; Pandy, Marcus G

2010-12-01

194

Energy Savings Potential for Commercial Refrigeration Equipment.  

National Technical Information Service (NTIS)

The study examined commercial refrigeration equipment (supermarkets, refrigerated vending machines, beverage merchandisers, reach-in and walk-in refrigerators and freezers, and ice machines). Baseline energy use, potential energy savings, and the economic...

D. Westphalen R. A. Zogg A. F. Varone M. A. Foran

1996-01-01

195

Exam Question Exchange: Potential Energy Surfaces.  

ERIC Educational Resources Information Center

|Presents three examination questions, graded in difficulty, that explore the topic of potential energy surfaces using a diagrammatic approach. Provides and discusses acceptable solutions including diagrams. (CW)|

Alexander, John J., Ed.

1988-01-01

196

High-energy asymptotic behavior of the Bourrely-Soffer-Wu model for elastic scattering  

NASA Astrophysics Data System (ADS)

Some time ago, an accurate phenomenological approach, the BSW model, was developed for proton-proton and antiproton-proton elastic scattering cross sections at center-of-mass energies above 10 GeV. This model has been used to give successful theoretical predictions for these processes, at successive collider energies. The BSW model involves a combination of integrals that, while computable numerically at fairly high energies, require some mathematical analysis to reveal the high-energy asymptotic behavior. In this paper we present a high-energy asymptotic representation of the scattering amplitude at moderate momentum transfer, for the leading order in an expansion parameter closely related to the logarithm of the center-of-mass energy. The fact that the expansion parameter goes as the logarithm of the energy means that the asymptotic behavior is accurate only for energies greatly beyond any foreseeable experiment. However, we compare the asymptotic representation against the numerically calculated model for energies in a less extreme region of energy. The asymptotic representation is given by a simple formula which, in particular, exhibits the oscillations of the differential cross section with momentum transfer. We also compare the BSW asymptotic behavior with the Singh-Roy unitarity upper bound for the diffraction peak.

Bourrely, Claude; Myers, John M.; Soffer, Jacques; Wu, Tai Tsun

2012-05-01

197

The effect of elastic strain on energy band gap and lattice parameter in III-V compounds  

Microsoft Academic Search

The elastic and misfit strain in vapor-grown InGaP\\/GaAs crystals was determined by measuring the lattice parameter of the InGaP before and after removal of the GaAs substrate. The energy-band-gap shift as a function of strain was measured in a similar manner using photoluminescence. Up to 70% of the misfit strain was found to be accommodated elastically. The critical resolved shear

G. H. Olsen; C. J. Nuese; R. T. Smith

1978-01-01

198

Differential elastic electron scattering cross sections for ethane in the energy range from 2 to 100 eV  

Microsoft Academic Search

Cross sections for vibrationally elastic scattering of the system e-C2H6 have been measured with a newly constructed apparatus of the crossed-beam type using the relative flow technique. Absolute elastic differential cross sections for C2H6 were obtained by measuring the ratios to the cross section for He at impact energies of 2, 3, 4, 5, 6, 7.5, 8.5, 10, 15, 20,

H. Tanaka; L. Boesten; D. Matsunaga; T. Kudo

1988-01-01

199

Energy conservation and pulse propagation in an elastic medium with quadratic nonlinearity  

NASA Astrophysics Data System (ADS)

A sinusoidal acoustic tone-burst launched into an elastic medium with weak quadratic nonlinearity is shown to generate a right-triangular static displacement pulse, when conservation of energy is properly imposed on the model equations. The right-triangular displacement profile is shown to occur whether the tone-burst is modeled with displacement-prescribed or traction-prescribed boundary conditions. Definitive experimental evidence is presented confirming the model predictions. Theoretical arguments and experimental evidence are also presented showing that, contrary to the assertion of Qu et al. [J. Acoust. Soc. Am. 131, 1827 (2012)], the right-triangular shape is not in violation of causality.

Cantrell, John H.; Yost, William T.

2012-09-01

200

Cotton Stalk as a Potential Energy Source  

Microsoft Academic Search

Policymakers have a growing interest in the development of domestic energy sources. One renewable energy source, biomass, is receiving consideration as a potential energy source. Among agricultural biomass materials, crop residue has energy value in direct combustion and gasification as well as in the manufacture of hydrocarbon fuels. The main objective of the present study is to investigate many aspects

R. CENGIZ AKDENIZ; MUSTAFA ACAROGLU; ARIF HEPBASLI

2004-01-01

201

The biomass energy potential of Mississippi  

Microsoft Academic Search

The current and potential future contribution of biomass energy to the energy consumption of Mississippi was estimated through a county-level inventory. In 1989, 91 industrial or commercial facilities were found to burn wood, municipal solid waste, or rice hulls for energy, with an estimated energy contribution of 58.7 trillion Btu. Other commercial biomass industries found to make contributions to Mississippi's

H. M. Draper; R. T. Jr. Brooks; J. D. Thomas; L. A. Weaver

1989-01-01

202

Differential cross sections of elastic electron scattering from CH4, CF4 and SF6 in the energy range 100 700 eV  

NASA Astrophysics Data System (ADS)

We investigate the differential cross sections (DCS) of elastic electron scattering from CH4, CF4 and SF6 at six impact energies in a range of 100-700 eV by employing the independent atom model (IAM) together with the relativistic partial waves. The atom is present in an optical potential which is complex, spherically symmetric, and energy dependent. The optical potential of the atom is the sum of the direct static, dynamic polarization, local exchange and modified absorption potentials. The results obtained by using a modified absorption potential show significant improvements on the unmodified absorption potential results. The present results are generally in good agreement with experimental data available. In addition, the present results indicate that the structure of molecule manifests the observable effects on electron-molecule scattering.

Ma, Er-Jun; Ma, Yu-Gang; Cai, Xiang-Zhou; Fang, De-Qing; Shen, Wen-Qing; Tian, Wen-Dong

2007-11-01

203

The elastic and inelastic scattering of intermediate energy protons on deuterium at small momentum transfer  

NASA Astrophysics Data System (ADS)

The differential cross sections for the elastic and inelastic scattering of protons on deuterium have been measured for scattering angles less than 14° at 198.5, 297.6 and 456.6 MeV. These quantities were determined relative to d? / d? for pp elastic scattering with a precision of typically 2%. The range of excitation energies for the (p, p') reaction was chosen to emphasize the region near the np threshold dominated by the final-state interaction in the 1S0 channel. Particular attention was given to the dependence on excitation energy of the spectra at 198.5 MeV to examine the sensitivity to the 1S0 scattering length, anp In this paper all data are compared with a new, detailed formulation of a simple model of the reaction mechanism based on the impulse approximation. The experimental results differ from the predictions by typically 10% and the differential cross sections exhibit a sensitivity to the intermediate-energy nucleon-nucleon amplitudes. If the impulse approximation is used to estimate anp from the data at 198.5 MeV a value of - 24.7 +/- 0.4 fm is obtained.

Burzynski, S.; Jackson, K. P.; Alford, W. P.; Cromer, J. E.; Helmer, R.; King, B. E.; Šlaus, I.; Spicer, B.; Trudel, A.; Yen, S.

1994-04-01

204

An empirical many-body potential energy function constructed from pair-interactions  

Microsoft Academic Search

A new empirical potential energy function (PEF) is proposed, which is formed from pair-interactions only, and containes the many-body contributions. The PEF satisfies bulk cohesive energy and bulk stability condition. The PEF is parameterized for copper, silver, and gold elements in fcc crystal structure. The elastic constantsC11 andC12 and the bulk modulus of the elements are calculated, and the structural

?Sakir Erkoç

1994-01-01

205

Experimental study of {sup 6}He+{sup 9}Be elastic scattering at low energies  

SciTech Connect

New data for the {sup 6}He+{sup 9}Be reaction at E{sub lab}=16.2 and 21.3 MeV have been taken and analyzed. The effect of the collective couplings to the excited states of the target has been studied by means of coupled-channels calculations, using a double-folding potential for the bare interaction between the colliding nuclei, supplemented with a phenomenological imaginary part of Woods-Saxon type. In addition, three- and four-body continuum-discretized coupled-channels calculations have been performed to investigate the effect of the projectile breakup on the elastic scattering. Both effects, the coupling to target and projectile excited states, are found to affect significantly the elastic scattering. The trivial local polarization potential extracted from the continuum-discretized coupled-channels calculations indicates that continuum couplings produce a repulsive real part and a long-range imaginary part in the projectile-target interaction.

Pires, K. C. C.; Lichtenthaeler, R.; Lepine-Szily, A.; Guimaraes, V.; Faria, P. N. de; Barioni, A.; Mendes Junior, D. R.; Morcelle, V.; Pampa Condori, R.; Morais, M. C.; Zamora, J. C.; Crema, E.; Moro, A. M.; Rodriguez-Gallardo, M.; Assuncao, M.; Shorto, J. M. B.; Mukherjee, S. [Departamento de Fisica Nuclear, Universidade de Sao Paulo, C.P. 66318, 05389-970, Sao Paulo (Brazil); Departamento de FAMN, Facultad de Fisica, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla (Spain); Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid, Spain Departamento de FAMN, Facultad de Fisica, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla (Spain); Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, Campus Diadema, Sao Paulo (Brazil); Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Sao Paulo (Brazil); Physics Department, Faculty of Science, M.S. University of Baroda, Vadodara (India)

2011-06-15

206

Potential Water and Energy Savings from Showerheads  

SciTech Connect

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.

Biermayer, Peter J.

2005-09-28

207

Wind energy potential of Algeria  

Microsoft Academic Search

Mean wind data for 64 stations, 48 of which are located in Algeria and 16 in neighbouring countries has been used to establish the wind energy map of Algeria at a height of 10 m. It is found that the wind speed varies between 1 and 6 m\\/s. The windy regions are located at the west south of Algeria, in

N. Kasbadji Merzouk

2000-01-01

208

Systematic failure of the Woods-Saxon nuclear potential to describe both fusion and elastic scattering: Possible need for a new dynamical approach to fusion  

NASA Astrophysics Data System (ADS)

A large number of precision fusion excitation functions, at energies above the average fusion barriers, have been fitted using the Woods-Saxon form for the nuclear potential in a barrier passing model of fusion. They give values for the empirical diffuseness parameter a ranging between 0.75 and 1.5 fm , compared with values of about 0.65 fm which generally reproduce elastic scattering data. There is a clear tendency for the deduced a to increase strongly with the reaction charge product Z1 Z2 , and some evidence for the effect of nuclear structure on the value of a , particularly with regard to the degree of neutron richness of the fusing nuclei, and possibly with regard to deformation. The measured fusion-barrier energies are always lower than those of the bare potentials used, which is expected as a result of adiabatic coupling to high energy collective states. This difference increases with increasing Z1 Z2 and calculations show that about 1/3 of it may be attributed to coupling to the isoscalar giant-quadrupole resonances in the target and projectile. Coupling to all giant resonances may account for a significant part. Fluctuations about the trend line may be due to systematic errors in the data and/or structure effects such as coupling to collective octupole states. Previously suggested reasons for the large values of a have been related to departures from the Woods-Saxon potential and to dissipative effects. This work suggests that the apparently large values of a may be an artifact of trying to describe the dynamical fusion process by use of a static potential. Another partial explaination might reside in fusion inhibition, due for example to deep-inelastic scattering, again a process requiring dynamical calculations.

Newton, J. O.; Butt, R. D.; Dasgupta, M.; Hinde, D. J.; Gontchar, I. I.; Morton, C. R.; Hagino, K.

2004-08-01

209

Cross-sections for the elastic recoil of hydrogen isotopes for high energy helium ions  

NASA Astrophysics Data System (ADS)

Cross-sections for the elastic recoil of hydrogen isotopes, including tritium, have been measured for 4He2+ ions in the energy range of 9.0-11.6 MeV. These cross-sections have been measured at a scattering angle of 30° in the laboratory frame. Cross-sections were measured by allowing a 4He2+ beam to fall incident on solid targets of ErH2, ErD2 and ErT2, each of 500 nm nominal thickness and known areal densities of H, D, T and Er. The uncertainty in each cross-section is estimated to be +/-3.2%. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

Browning, J. F.; Banks, J. C.; Wampler, W. R.; Doyle, B. L.

2004-06-01

210

Cross sections for elastic electron scattering by tetramethylsilane in the intermediate-energy range  

NASA Astrophysics Data System (ADS)

Organosilicon compounds are of current interest due to the numerous applications of these species in industries. Some of these applications require the knowledge of electron collision cross sections, which are scarce for such compounds. In this work, we report absolute values of differential, integral, and momentum-transfer cross sections for elastic electron scattering by tetramethylsilane (TMS) measured in the 100-1000 eV energy range. The relative-flow technique is used to normalize our data. In addition, the independent-atom-model (IAM) and the additivity rule (AR), widely used to model electron collisions with light hydrocarbons, are also applied for e--TMS interaction. The comparison of our measured results of cross sections and the calculated data shows good agreement, particularly near the higher-end of incident energies.

Sugohara, R. T.; Lee, M.-T.; de Souza, G. L. C.; Homem, M. G. P.; Iga, I.

2011-12-01

211

Renewable energy resource potential in Pakistan  

Microsoft Academic Search

Pakistan energy situation is seriously troubling today due to lack of careful planning and implementation of its energy policies. To avoid the worse situation in the years ahead, the country will have to exploit its huge natural renewable resource. In this paper a review is being presented about renewable energy resource potential available in the country to be exploited for

Munawar A. Sheikh

2009-01-01

212

Geothermal Energy Potential in Western United States  

ERIC Educational Resources Information Center

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)

Pryde, Philip R.

1977-01-01

213

Geothermal Energy Potential in Western United States  

ERIC Educational Resources Information Center

|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)|

Pryde, Philip R.

1977-01-01

214

Substitution potential of wind energy in Egypt  

Microsoft Academic Search

The amount of energy generated by conventional power plants is expected to decline in near future due to environmental concern and the possible penetration of renewable energy such as wind generation. Therefore, the evaluation of the substitution potential of wind energy is becoming an important task by generation planning of power systems. A new methodology for estimating the capacity credit

Mohamed A. H. El-Sayed

2002-01-01

215

On the asymptotic approximation for the elastic scattering by a potential  

Microsoft Academic Search

Summary  — The set of approximations usually known as the « semi-classical description of scattering » is developed in such a way that\\u000a the next orders in the asymptotic expansions may be calculated. An additional approximation enables one to treat the effects\\u000a of surface potentials and, in particular, spin-orbit potentials. In order to avoid nonessential difficulties, the derivation\\u000a is done in

P. C. Sabatier

1965-01-01

216

Diuretic potential of energy drinks  

Microsoft Academic Search

Summary.  Recent literature suggests that both caffeine and taurine can induce diuresis and natriuresis in rat and man. Although they\\u000a act via different cellular mechanisms, their diuretic actions might be additive. This is of considerable interest, as several\\u000a commercially available energy drinks contain both substances.\\u000a \\u000a In this study we examined the possible diuretic effects of caffeine and taurine in a cross-over-design

A. Riesenhuber; M. Boehm; M. Posch; C. Aufricht

2006-01-01

217

Elastic field of a surface step: Atomistic simulations and anisotropic elastic theory  

Microsoft Academic Search

Atomistic computer simulations and anisotropic elastic theory are employed to determine the elastic fields of surface steps and vicinal surfaces. The displacement field of and interaction energies between {l_angle}100{r_angle} steps on a {l_brace}001{r_brace} surface of Ni and Au are determined using atomistic simulations and embedded-atom method potentials. The step-step interaction energy found from the simulations is consistent with a surface

L. E. Shilkrot; D. J. Srolovitz

1996-01-01

218

Crystallography and elastic energy analysis of VN precipitates in Fe-Mn-Si-Cr shape memory alloys  

SciTech Connect

High-resolution electron microscopy investigations are carried out to describe the morphology and crystallography of VN precipitates which are formed in an Fe-28Mn-6Si-5Cr (mass%) shape memory alloy. It is revealed that the shape change from a cube with (1 0 0) interfaces to an octahedral shape with (1 1 1) interfaces occurs on aging in the precipitate. In order to identify the equilibrium shape of the VN precipitate, elastic strain energy of the precipitate has been estimated on the basis of microscopic theory of elasticity. It is found that a coherent precipitate ({approx}4 nm in edge width) in a cube shape with (1 0 0) surfaces can be formed, at an early stage of precipitation, with no misfit dislocations existing at the interface of the precipitate. It is also shown that the octahedral-shaped precipitate ({approx}15 nm in edge width) has a minimum elastic energy, among the cube-shaped, sphere-shaped and octahedron-shaped precipitates, only when the misfit dislocations are introduced at the interfaces. The elastic interaction energy between the misfit dislocations and the precipitate-misfit dislocations is estimated for the first time using the Fourier transformed microscopic theory of elasticity.

Farjami, Susan [Department of Materials Processing, Graduate School of Engineering, Tohoku University, Aobayama 02, Sendai 980-8579 (Japan)]. E-mail: sfarjami@stu.material.tohoku.ac.jp; Hiraga, Kenji [Nanotechnology Research Network Center of Japan at Tohoku University Materials Research Center, Sendai 980-8577 (Japan); Kubo, Hiroshi [Institue of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

2005-01-10

219

Unlocking potential for energy reduction.  

PubMed

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

O'Leary, John

2013-05-01

220

Energy potential of modern landfills  

SciTech Connect

Methane produced by refuse decomposition in a sanitary landfill can be recovered for commercial use. Landfill methane is currently under-utilized, with commercial recovery at only a small percentage of US landfills. New federal regulations mandating control of landfill gas migration and atmospheric emissions are providing impetus to methane recovery schemes as a means of recovering costs for increased environmental control. The benefits of landfill methane recovery include utilization of an inexpensive renewable energy resource, removal of explosive gas mixtures from the subsurface, and mitigation of observed historic increases in atmospheric methane. Increased commercial interest in landfill methane recovery is dependent on the final form of Clean Air Act amendments pertaining to gaseous emissions from landfills; market shifts in natural gas prices; financial incentives for development of renewable energy resources; and support for applied research and development to develop techniques for increased control of the gas generation process in situ. This paper will discuss the controls on methane generation in landfills. In addition, it will address how landfill regulations affect landfill design and site management practices which, in turn, influence decomposition rates. Finally, future trends in landfilling, and their relationship to gas production, will be examined. 19 refs., 2 figs., 3 tabs.

Bogner, J.E.

1990-01-01

221

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

Microsoft Academic Search

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

Richard M. Iverson; Mark E. Reid

1992-01-01

222

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

Microsoft Academic Search

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

Richard M. Iverson; Mark E. Reid

1992-01-01

223

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

Microsoft Academic Search

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

Richard M. Iverson; Mark E. Reid

1992-01-01

224

Effects of elastic strain energy and interfacial stress on the equilibrium morphology of misfit particles in heterogeneous solids  

NASA Astrophysics Data System (ADS)

This paper presents an efficient sharp interface model to study the morphological transformations of misfit particles in phase separated alloys. Both the elastic anisotropy and interfacial energy are considered. The geometry of the material interface is implicitly described by the level set method so that the complex morphological transformation of microstructures can be accurately captured. A smoothed extended finite element method is adopted to evaluate the elastic field without requiring remeshing. The equilibrium morphologies of particles are shown to depend on the elastic anisotropy, interfacial energy as well as the particle size. Various morphological transformations, such as shape changes from spheres to cuboids, directional aligned platelets and particle splitting, are observed. The simulated results are in good agreement with experimental observations. The proposed model provides a useful tool in understanding the morphological transformation of precipitates, which will facilitate the analysis and design of metallic alloys.

Zhao, Xujun; Duddu, Ravindra; Bordas, Stéphane P. A.; Qu, Jianmin

2013-06-01

225

Potential Water and Energy Savings from Showerheads.  

National Technical Information Service (NTIS)

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 regardi...

P. J. Biermayer

2005-01-01

226

Study of the Energy Dependence of Elastic and Inelastic Scattering of OXYGEN-16 from NEON-20.  

NASA Astrophysics Data System (ADS)

A differentially pumped gas cell wih gas recycling system is used to study the scattering of ('16)O from ('20)Ne -gas target. Excitation functions and angular distributions are measured. Correlated energy dependence of the excitation functions measured at several angles is observed. A structure at E(,cm) (TURNEQ) 18. MeV is observed only in the elastic channel. A high resolution study with a thin target (p = 5 torr) was carried out at E(,cm) (TURNEQ) 24. MeV, as well as at the E(,cm) (TURNEQ) 19.7 MeV resonance in the ('16)O + ('12)C system. Structure of finer width does not appear statistically significant in both systems. Elastic scattering angular distributions measured at energies above the Coulomb barrier show backward rise and oscillatory pattern that resembles a single Legendre polynomial squared, except for the E(,cm) = 18.5 MeV angular distribution, which appears to be different. Optical model plus resonance(s) calculations are carried out. The angular distributions measured at E(,cm) = 24.2 and 24.7 MeV yield resonances in the \\= 17 partial wave at E(,cm) = 24.2 MeV with total width (GAMMA) (TURNEQ) 1.5 MeV. The angular distributions measured at E(,cm) = 17.4 and 18.5 MeV are consistent with a resonance in the \\= 12 partial wave at E(,cm) = 17.4 MeV with (GAMMA) (TURNEQ) 2.0 MeV and a resonance in the \\= 8 partial wave at E(,cm) = 18.5 MeV with smaller total width. The last is observed within the strong absorption limit. At E(,cm) = 18.5 MeV an interference of two levels J('(pi)) = 12('+) at 17.4 MeV and J('(pi)) = 8('+) at 18.5 MeV seems to appear. In this analysis the position of the resonance energy and the source of various channel dependent shifts of this energy is discussed. The 'elastic transfer' mechanism for the ('16)O + ('20)Ne system is investigated in a semi microscopic scheme where the total scattering amplitude consists of a coherent sum of direct elastic scattering and (alpha) transfer amplitudes. Microscopic form factor and (alpha) particle spectroscopic factor for ('20)Ne are used. This process is shown to contribute significantly to the cross section measured at the far backward region, but cannot explain the resonance-like structure. A phenomenological study of this process in terms of the 'parity dependent optical model' is carried out. This phenomenological model yields similar results as the microscopic model. Statistical analysis of the data yields some degree of channel-channel cross correlation and angular correlations, as well as 'coherence width of the intermediate width structure' (GAMMA)(intermediate) (GREATERTHEQ) 200 keV and 'coherence width of the gross structure' (GAMMA)(gross) (TURNEQ) 1. MeV. The importance of the ('16)O + ('20)Ne system as a bridge between the 'light systems' (...('16)O + ('12)C...) and the 'heavy systems' (...('16)O + ('28)Si...) is discussed in the frame of a systematic study of heavy ion resonances. In the appendix a unique simple correlation between the systems ('16)O + ('20)Ne and ('16)O + ('12)C as well as many other systems is discussed. It is suggested that the most pronounced anomalies in the different systems exhibit order.

Gai, Moshe

1980-12-01

227

A Jost function description of zero-energy resonance and transparency effects in elastic collisions  

NASA Astrophysics Data System (ADS)

Under certain circumstances, an elastic cross section at very low energies could differ by orders of magnitude above or below any reasonable estimate. The first case occurs near a zero-energy resonance, while the second one is akin to the well-known Ramsauer-Townsend effect. In spite of their intrinsic similarity, both effects are usually explained in very different ways, either in terms of poles of the scattering matrix or by means of a partial-wave analysis, respectively. In this paper we show that a unified description is actually possible. We demonstrate that in a zero-energy resonance or transparency, the standard ?2? threshold law of the ?-wave cross section is changed into ?2(? - 1) (?-1 for ? = 0) or ?2(? + 1), respectively. Finally, we show that while the zero-energy resonance occurs whenever the scattering length associated to an individual zero of the Jost function diverges, the transparent scattering is a collective effect, where the sum of all the individual scattering lengths plays a relevant role.

Macri, P. A.; Barrachina, R. O.

2013-03-01

228

Steady state and time-dependent energy equilibration in two-dimensional random elastic slabs.  

PubMed

The static and dynamic transport properties of elastic wave propagation through two-dimensional random slabs without internal reflection were studied at two different scattering parameters: one for Rayleigh scattering and the other for Rayleigh-Gans scattering. The spatial distribution and temporal evolution of shear (s-) and compressional (p-) wave energy densities inside the slabs were calculated by solving the radiative transfer equation and the generalized diffusion equation (GDE). The comparison of their results can determine the region of validity of the GDE. The process of energy equilibration between the two wave modes was demonstrated explicitly as well as the process of diffusion. The depth inside a slab that is needed to reach energy equilibration or diffusive behavior is found to be dependent on source polarization. The results also show that the bulk equilibration ratio can be found inside a sample only when the sample is sufficiently thick. Deviations of the equilibration ratio from its bulk value are found near the output surface due to the absence of in-flow energy flux. The behavior of the deviations is sensitive to the scattering parameter but independent of source polarization. PMID:19813795

Wan, Yanyi; Wu, Ying; Zhang, Zhao-Qing

2009-10-01

229

Theoretical studies of potential energy surfaces  

SciTech Connect

MRCI (configuration interaction) calculations were used to examine possible pathways for the O{sub 2} + CCH reaction. The H{sub 2} + CN potential surface was examined. An initial survey was made of the HCl + CN potential energy surface at a low level of theory.

Harding, L.B.

1995-07-01

230

Potential for energy conservation in apartment buildings  

Microsoft Academic Search

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

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

2000-01-01

231

Study of the Spin/Orbit Term of the Spherical Optical Model Potential by Means of Large Angle Fast Neutron Elastic Scattering Angular Distribution Measurements.  

National Technical Information Service (NTIS)

The study of differential cross section angular distributions for neutron elastic scattering at large angles is a sensitive method for testing the effect of the choice of the numerical value of the spin-orbit term of the optical model potential. This is o...

E. Ramstroem B. Trostell

1978-01-01

232

Energy dependence of the charge asymmetry A(T/sub. pi. /,theta) in. pi. d elastic scattering  

SciTech Connect

Angular distributions of charge asymmetry A(T/sub ..pi../,theta), have been measured for ..pi..d elastic scattering. Data were obtained in the backward hemisphere for pion bombarding energies of 143, 180, 220, and 256 MeV. The results are compared with predictions employing different mass and width parameters for the delta isobars.

Smith, G.R.; Gill, D.R.; Ottewell, D.; Wait, G.D.; Walden, P.; Johnson, R.R.; Olszewski, R.; Rui, R.; Sevior, M.E.; Trelle, R.P.; and others

1988-07-01

233

Elastic scattering, vibrational excitation, and attachment in low-energy electron- S F6 scattering: Experiment and effective range theory  

Microsoft Academic Search

Cross sections at low energies for vibrationally elastic and inelastic scattering, as well as electron attachment to SF6 , have been calculated using a multichannel effective range theory (ERT) with complex boundary conditions. The most active vibrational modes, the totally symmetric mode nu1 and the infrared active mode nu3 , have been included in the calculation. The ERT parameters were

Ilya I. Fabrikant; Hartmut Hotop; Michael Allan

2005-01-01

234

Economic Energy Savings Potential in Federal Buildings  

SciTech Connect

The primary objective of this study was to estimate the current life-cycle cost-effective (i.e., economic) energy savings potential in Federal buildings and the corresponding capital investment required to achieve these savings, with Federal financing. Estimates were developed for major categories of energy efficiency measures such as building envelope, heating system, cooling system, and lighting. The analysis was based on conditions (building stock and characteristics, retrofit technologies, interest rates, energy prices, etc.) existing in the late 1990s. The potential impact of changes to any of these factors in the future was not considered.

Brown, Daryl R.; Dirks, James A.; Hunt, Diane M.

2000-09-04

235

Bound States of Energy Dependent Singular Potentials  

NASA Astrophysics Data System (ADS)

We consider attractive power-law potentials depending on energy through their coupling constant. These potentials are proportional to 1/| x| m with m ? 1 in the D = 1 dimensional space, to 1/ r m with m ? 2 in the D = 3 dimensional space. We study the ground state of such potentials. First, we show that all singular attractive potentials with an energy dependent coupling constant are bounded from below, contrarily to the usual case. In D = 1, a bound state of finite energy is found with a kind of universality for the eigenvalue and the eigenfunction, which become independent on m for m > 1. We prove the solution to be unique. A similar situation arises for D = 3 for m > 2, except that, in this case, the solution is not directly comparable to a bound state: the wave function, though square integrable, diverges at the origin.

Yekken, R.; Lassaut, M.; Lombard, R. J.

2013-11-01

236

Trajectory integration with potential energy discontinuities  

SciTech Connect

Many approximate methods of quantum chemistry yield potential energy surfaces with discontinuities. While clearly unphysical, such features often fall within the typical error bounds of the method, and cannot be easily eliminated. The integration of nuclear trajectories when the potential energy is locally discontinuous is obviously problematic. We propose a method to smooth out the discontinuities that are detected along a trajectory, based on the definition of a continuous function that fits locally the computed potential, and is used to integrate the trajectory across the discontinuity. With this correction, the energy conservation error can be reduced by about one order of magnitude, and a considerable improvement is obtained in the energy distribution among the internal coordinates.

Hurd, Patricia [Arizona State University, School of Mechanical, Aerospace, Chemical and Materials Engineering, P. O. Box 876106, Tempe, Arizona 85287-6106 (United States); Cusati, Teresa [Universita di Pisa, Dipartimento di Chimica e Chimica Industriale v. Risorgimento 35, I-56126 Pisa (Italy); Persico, Maurizio [Universita di Pisa, Dipartimento di Chimica e Chimica Industriale v. Risorgimento 35, I-56126 Pisa (Italy)], E-mail: mau@dcci.unipi.it

2010-03-20

237

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

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.

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

238

Do halo nuclei follow Rutherford elastic scattering at energies below the barrier? The case of 11Li.  

PubMed

The first measurement of the elastic scattering of the halo nucleus 11Li and its core 9Li on 208Pb at energies near the Coulomb barrier is presented. The 11Li+208Pb elastic scattering shows a strong reduction with respect to the Rutherford cross section, even at energies well below the barrier and down to very small scattering angles. This drastic change of the elastic differential cross section observed in 11Li+208Pb is the consequence of the halo structure of 11Li, as it is not observed in the elastic scattering of its core 9Li at the same energies. Four-body continuum-discretized coupled-channels calculations, based on a three-body model of the 11Li projectile, are found to explain the measured angular distributions and confirm that the observed reduction is mainly due to the strong Coulomb coupling to the dipole states in the low-lying continuum of 11Li. These calculations suggest the presence of a low-lying dipole resonance in 11Li close to the breakup threshold. PMID:23368554

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

2012-12-26

239

Do Halo Nuclei Follow Rutherford Elastic Scattering at Energies Below the Barrier? The Case of Li11  

NASA Astrophysics Data System (ADS)

The first measurement of the elastic scattering of the halo nucleus Li11 and its core Li9 on Pb208 at energies near the Coulomb barrier is presented. The Li11+Pb208 elastic scattering shows a strong reduction with respect to the Rutherford cross section, even at energies well below the barrier and down to very small scattering angles. This drastic change of the elastic differential cross section observed in Li11+Pb208 is the consequence of the halo structure of Li11, as it is not observed in the elastic scattering of its core Li9 at the same energies. Four-body continuum-discretized coupled-channels calculations, based on a three-body model of the Li11 projectile, are found to explain the measured angular distributions and confirm that the observed reduction is mainly due to the strong Coulomb coupling to the dipole states in the low-lying continuum of Li11. These calculations suggest the presence of a low-lying dipole resonance in Li11 close to the breakup threshold.

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

2012-12-01

240

Energy conservation in Kenya: progress, potentials, problems  

SciTech Connect

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.

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

1981-09-01

241

Recent results in the development of a global medium-energy nucleon-nucleus optical-model potential  

Microsoft Academic Search

Initial results are presented for the determination of a global medium-energy nucleon-nucleus phenomenological optical-model potential using a relativistic Schroedinger representation. The starting point for this work is the global phenomenological optical-model potential of Schwandt )ital et al.), which is based on measured elastic scattering cross sections and analyzing power for polarized protons ranging from 80 to 180 MeV. This potential

Madland

1988-01-01

242

Asymmetry measurement of pion elastic scattering from polarized 13C in the energy region of the P33 resonance  

NASA Astrophysics Data System (ADS)

Analyzing powers Ay were measured for ?+ and ?- elastic scattering from polarized 13C at energies near the P33 resonance. At T?=132 MeV the values of Ay are significantly different from zero for ?-. For ?+ at 132 MeV and for both ?- and ?+ at all other energies, the Ay are mostly consistent with zero. These data differ from the predictions of present pion-nucleus reaction theories, especially at large momentum transfers.

Yen, Yi-Fen; Brinkmöller, B.; Dehnhard, D.; Sterbenz, S. M.; Yu, Yi-Ju; Berman, Brian; Burleson, G. R.; Cranston, K.; Klein, A.; Kyle, G. S.; Alarcon, R.; Averett, T.; Comfort, J. R.; Görgen, J. J.; Ritchie, B. G.; Tinsley, J. R.; Barlett, M.; Hoffmann, G. W.; Johnson, K.; Moore, C. F.; Purcell, M.; Ward, H.; Williams, A.; Faucett, J. A.; Greene, S. J.; Jarmer, J. J.; McGill, J. A.; Morris, C. L.; Penttilä, S.; Tanaka, N.; Fortune, H. T.; Insko, E.; Ivie, R.; O'donnell, J. M.; Smith, D.; Khandaker, M. A.; Chakravarti, S.

1991-04-01

243

Determination of solid material elastic modulus and surface energy based on JKR contact model  

NASA Astrophysics Data System (ADS)

The JKR contact theory is employed to study the adhesion phenomena between two solid materials in intimate contact. The elastic contact modulus and the work of adhesion of solid materials are obtained during adhesion tests by utilizing a micro force-deflection measuring apparatus. Six of the plastic materials, including polyethylene polyoxymethlene (POM), polyamide (PA), terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), and ultra-high molecular weight polyethylene (UHMWPE) are used to evaluate the adhesion effect implied by the JKR theory. Comparison is made between surface energy obtained from the adhesion tests with that by a dynamic contact angle analyser. Results show that the load/deflection data in the loading phase are in good agreement with the predictions of JKR equation, and the experimental data of unloading phase deviate significantly from the JKR theory. The phenomena of adhesion hysteresis in loading tests are responsible for these results due to the effects of molecular reconstruction on solid surfaces in contact. The work of adhesions, and hence surface energies of plastic materials, calculated by the best fitting of JKR equation with the experimental data in the loading phase, agree satisfactorily in a comparable manner with that obtained using the contact angle analyser.

Wu, Kuang-Chung; You, Hsien-I.

2007-08-01

244

The role of chemical free energy and elastic strain in the nucleation of zirconium hydride  

NASA Astrophysics Data System (ADS)

In this work a combination of synchrotron X-ray diffraction and thermodynamic modelling has been used to study the dissolution and precipitation of zirconium hydride in ?-Zr establishing the role of elastic misfit strain and chemical free energy in the ? ? ? + ? phase transformation. The nucleation of zirconium hydride is dominated by the chemical free energy where the chemical driving force for hydride precipitation is proportional to the terminal-solid solubility for precipitation and can be predicted by a function that is analogous to the universal nucleation parameter for the bainite transformation in ferrous alloys. The terminal-solid solubility for precipitation was found to be kinetically limited ?287 °C at a cooling rate of 5 °C min-1 or greater. The terminal solubilities were established using an offset method applied to the lattice strain data where a resolution of ˜10 wppm H can be achieved in the -direction. This is aided by the introduction of intra-granular strains in the -direction during cooling as a result of the thermal expansion anisotropy which increases the anisotropy associated with the misfitting H atoms within the ?-Zr lattice.

Barrow, A. T. W.; Toffolon-Masclet, C.; Almer, J.; Daymond, M. R.

2013-10-01

245

Elastic Transient Energy Transport and Energy Balance in a Single-Level Quantum Dot System  

NASA Astrophysics Data System (ADS)

We derive a nonequilibrium Green's function formalism to study the transient energy currents carried by electrons in a single-level quantum dot system sandwiched between two electrodes. The energy current shows the same relaxation time and oscillation behavior as the electrical current. In contrast to the steady state case, the energy currents in deep insides of the two electrodes do not balance each other in the time domain. The sum of energy currents in the two electrodes corresponds to the time-dependent energy change in the sandwiched region, and the fact that the energy change in this region is not necessarily zero reflects the real-time electron redistribution in energy domain. Moreover, the amplitude of the energy change does not vary monotonically with the coupling strength between the dot and electrode, in contrast to the relaxation time, which is inversely proportional to the coupling strength.

Liu, Wei; Sasaoka, Kenji; Yamamoto, Takahiro; Tada, Tomofumi; Watanabe, Satoshi

2012-09-01

246

Potential energy surfaces for cluster emitting nuclei  

SciTech Connect

Potential energy surfaces are calculated by use of the most advanced asymmetric two-center shell model that allows us to obtain shell-and-pairing corrections that are added to the Yukawa-plus-exponential model deformation energy. Shell effects are of crucial importance for the experimental observation of spontaneous disintegration by heavy-ion emission. Results for {sup 222}Ra, {sup 232}U, {sup 236}Pu, and {sup 242}Cm illustrate the main ideas and show for the first time, for a cluster emitter, a potential barrier obtained by use of the macroscopic-microscopic method.

Poenaru, Dorin N.; Gherghescu, Radu A. [Horia Hulubei National Institute of Physics and Nuclear Engineering, RO-077125 Bucharest-Magurele (Romania); Frankfurt Institute for Advanced Studies, J. W. Goethe Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany); Greiner, Walter [Frankfurt Institute for Advanced Studies, J. W. Goethe Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany)

2006-01-15

247

Potential energy function for the hydroperoxyl radical  

SciTech Connect

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.

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

1987-03-12

248

Potential to Kinetic Energy Demonstration: Principles of Energy Transfer  

NSDL National Science Digital Library

The Materials Science and Technology Teacher's Workshop (MAST) provides this activity to illustrate the principles of energy transfer. The demonstration uses a balance, matches, soda cans and a firecracker to show how energy can transfer between light, sound, heat and kinetic energy. Potential and kinetic energy are defined and explored. The lesson includes step by step directions for the experiment. Discussion questions are also included.

2012-03-07

249

Ultrasonic energy flux deviation and off-diagonal elastic constants of wood  

Microsoft Academic Search

Wood is a natural, inhomogeneous, anisotropic composite material whose elastic behavior can successfully be described as that of an orthotropic continuum. Christoffel's equation relates ultrasonic propagation velocities to the elastic constants. Six of the nine independent constants can readily be determined from velocity measurements in the directions of the symmetry axes. Determination of the remaining three constants can proceed by

Voichita Bucur; Harald Berndt

2001-01-01

250

Wave energy potential in Galicia (NW Spain)  

Microsoft Academic Search

Wave power presents significant advantages with regard to other CO2-free energy sources, among which the predictability, high load factor and low visual and environmental impact stand out. Galicia, facing the Atlantic on the north-western corner of the Iberian Peninsula, is subjected to a very harsh wave climate; in this work its potential for energy production is assessed based on three-hourly

G. Iglesias; M. López; R. Carballo; A. Castro; J. A. Fraguela; P. Frigaard

2009-01-01

251

Elastic proteins: biological roles and mechanical properties  

Microsoft Academic Search

The term 'elastic protein' applies to many structural proteins with diverse functions and mechanical properties so there is room for confusion about its meaning. Elastic implies the property of elasticity, or the ability to deform reversibly without loss of energy; so elastic proteins should have high resilience. Another meaning for elastic is 'stretchy', or the ability to be deformed to

John Gosline; Margo Lillie; Emily Carrington; Paul Guerette; Christine Ortlepp; Ken Savage

2002-01-01

252

Linear terms in the spatial derivatives of the director in the elastic energy density for nematic liquid crystals  

NASA Astrophysics Data System (ADS)

We show that for materials having the nematic symmetry the spontaneous splay and the splay-bend elastic constants can be considered to be identically zero. The analysis is performed by assuming that in the bulk, the ground state of the nematic phase is the undistorted one. In this framework it is possible to build an elastic theory for nematic materials without the spontaneous splay and the splay-bend elastic constants. Our results follow from the hypothesis that in the bulk the energy density of a uniform nematic is independent of the average molecular orientation. Close to a surface, where the free energy density is expected to depend also on the orientation of the nematic director, we show that it is possible to define ``effective'' spontaneous splay and splay-bend elastic constants due to the reduced symmetry of the nematic liquid crystal in the surface layer and to the possible presence of ``surface fields''. Our analysis agrees with the one recently presented by Yokoyama.

Barbero, G.; Ponti, S.

1998-03-01

253

Biomass resource potential using energy crops  

SciTech Connect

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.

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

1993-09-01

254

The wind energy potential of western Greece  

Microsoft Academic Search

In this study wind data were used to determine the monthly and annual variations of the wind at 13 meterological stations in western Greece. An analysis of the available wind data for the Ionian Sea islands and the western coasts of Greece is carried out to ascertain its potential for wind energy development. The effect of the limited number of

B. D. Katsoulis; D. A. Metaxas

1992-01-01

255

Bohmian Dynamics on Multiple Potential Energy Surfaces  

Microsoft Academic Search

The coupled Schrodinger equations that describe nonadiabatic dynamics on multiple potential energy surfaces are recast using the Bohm formulation of quantum mechanics. The resulting coupled Bohm equations are exact; i.e., numerical solutions are identical to those obtained from the original coupled Schrodinger equations by wave packet propagation. The classical limit of the coupled Bohm equations is derived. It corresponds to

John Burant; John Tully

2001-01-01

256

Energy potential of sugarcane and sweet sorghum  

Microsoft Academic Search

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 Câ 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

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

1980-01-01

257

Elastic internal flywheel gimbal  

SciTech Connect

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.

Rabenhorst, D.W.

1981-01-13

258

Forward pd elastic scattering and total spin-dependent pd cross sections at intermediate energies  

SciTech Connect

Spin-dependent total pd cross sections are considered using the optical theorem. For this aim the full spin dependence of the forward pd elastic scattering amplitude is considered in a model independent way. The single-scattering approximation is used to relate this amplitude to the elementary amplitudes of pp and pn scattering and the deuteron form factor. A formalism allowing to take into account Coulomb-nuclear interference effects in polarized pd cross sections is developed. Numerical calculations for the polarized total pd cross sections are performed at beam energies 20-300 MeV using the NN interaction models developed by the Juelich group. Double-scattering effects are estimated within the Glauber approach and found to be in the order of 10-20%. Existing experimental data on differential pd cross sections are in good agreement with the performed Glauber calculations. It is found that for the used NN models the total longitudinal and transversal pd cross sections are comparable in absolute value to those for pp scattering.

Uzikov, Yu. N. [Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Haidenbauer, J. [Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany)

2009-02-15

259

Electron impact calculations of total elastic cross sections over a wide energy range - 0.01 eV to 2 keV for CH4, SiH4 and H2O  

NASA Astrophysics Data System (ADS)

In this paper we report the results of a new theoretical methodology for determining the total elastic electron scattering cross section, Q el , over a wide range of incident energies between 0.01 eV and 2 keV. We have combined results from the UK molecular R-matrix code using Quantemol-N software to determine Q el for incident energies between 0.01 eV and the ionization threshold of the target with calculations based on the spherical complex optical potential formalism for higher energies up to 2 keV. We present results for three selected molecular targets; CH4, SiH4 and H2O as exemplars of the methodology. The present results were found to be in good agreement with previous experimental and theoretical results. The total elastic cross sections for such a wide energy range are reported perhaps for the first time.

Vinodkumar, M.; Limbachiya, C. G.; Joshipura, K. N.; Mason, N. J.

2011-02-01

260

An energy-based fatigue failure model for super-elastic NiTi alloys under pure mechanical cyclic loading  

NASA Astrophysics Data System (ADS)

The fatigue failure of a super-elastic NiTi alloy was observed by uniaxial stress-controlled cyclic tests. During the cyclic loading a hysteresis loop with a varied but stabilized size after certain cycles was obtained, which is similar to plastic shakedown. The material exhibits unique brittle fracture with a large transformation strain. The fatigue life of the material greatly depends on the applied peak nominal stress, the nominal stress amplitude and the mean nominal stress. A relation between the dissipation energy at the stabilized stage of cyclic loading and the number of cycles at failure was derived from the experimental results. Based on the obtained experimental results, a uniaxial fatigue failure model based on the energy approach was proposed to predict the fatigue life. It was shown that the proposed model provides good predictions to the uniaxial fatigue lives of super-elastic NiTi alloys with different types of cyclic stressing.

Kan, Qianhua; Kang, Guozheng; Yan, Wenyi; Dong, Yawei; Yu, Chao

2011-11-01

261

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

SciTech Connect

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.

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

262

General properties of energy independent nuclear optical model potentials  

NASA Astrophysics Data System (ADS)

An energy independent optical potential for nucleon-nucleus scattering is formally derived. A simple relation between energy dependent and energy independent potentials is established showing that the latter has the same thresholds as the former. A generalized dispersion relation for energy independent potentials is found and compared to the conventional dispersion relation of the generalized energy dependent optical potentials. [REACTION THEORY General formulation of the energy independent optical potential.

Lee, S. Y.; Osterfeld, F.; Tam, K.; Kuo, T. T. S.

1981-08-01

263

Potential energy savings from aquifer thermal energy storage  

SciTech Connect

Pacific Northwest Laboratory researchers developed an aggregate-level model to estimate the short- and long-term potential energy savings from using aquifer thermal storage (ATES) in the United States. The objectives of this effort were to (1) develop a basis from which to recommend whether heat or chill ATES should receive future research focus and (2) determine which market sector (residential, commercial, or industrial) offers the largest potential energy savings from ATES. Information was collected on the proportion of US land area suitable for ATES applications. The economic feasibility of ATES applications was then evaluated. The potential energy savings from ATES applications was calculated. Characteristic energy use in the residential, commercial, and industrial sectors was examined, as was the relationship between waste heat production and consumption by industrial end-users. These analyses provided the basis for two main conclusions: heat ATES applications offer higher potential for energy savings than do chill ATES applications; and the industrial sector can achieve the highest potential energy savings for the large consumption markets. Based on these findings, it is recommended that future ATES research and development efforts be directed toward heat ATES applications in the industrial sector. 11 refs., 6 figs., 9 tabs.

Anderson, M.R.; Weijo, R.O.

1988-07-01

264

Exploring for the Sources of Internal Elastic Deformations Using Potential Fields and Their Poisson Wavelets; Possible Applications to InSAR Observations  

NASA Astrophysics Data System (ADS)

From a restricted solution of the Cauchy-Navier equations of quasi-static infinitesimal elasticity theory [Green and Zerna, 1968, section 5.7] for an isotropic, linear elastic half-space with a shear-traction free ground surface, we find a scalar function ? that is present underground wherever internal deformations are generated, and absent elsewhere. The "deformation source density" ? is related to the magnitude of changes in body forces (e.g. frictional traction changes across a creeping fault surface) and is the source of a potential field, like mass density for vertical gravitational acceleration, or the divergence of magnetization for total magnetic intensity. Surveys of surface displacements (e.g. InSAR range changes) may be turned into the potential field at the surface of the half-space via standard 2D Fourier domain techniques. From this potential, a harmonic field may be constructed above the measurement plane. All of potential field theory and practice [e.g., Blakely, 1996] is applicable to analyzing such data for information about the underground distribution and strength of ?. In particular the potential field Poisson wavelet system of Hornby, Boschetti,and Horowitz [1999] —-- being generated by the Green's function for harmonic potentials —-- is ideally suited for such analysis, with all of the multiscale edge ("worm") discontinuity analysis, and the dipole source inverse wavelet transform ideas being directly applicable. We regard this as a gentle approach "halfway to inversion" which allows for a visual interpretation of maps of surficial displacement measurements to occur before a full inversion is performed. References: Blakely, R. J. (1996), Potential Theory in Gravity and Magnetic Applications, Cambridge University Press, Cambridge. Green, A. E., and W. Zerna (1968), Theoretical Elasticity, 2nd ed., Oxford University Press, Clarendon. Hornby, P., F. Boschetti, and F. G. Horowitz (1999), Analysis of Potential Field Data in the Wavelet Domain, Geophysical Journal International, 137 (1), 175 -196, doi:10.1046/j.1365-246x.1999.00788.x.

Horowitz, F. G.; Hornby, P.

2006-12-01

265

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

SciTech Connect

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.

Rehm, K.E.

1988-01-01

266

Studies of electrochemical oxidation of Zircaloy nuclear reactor fuel cladding using time-of-flight-energy elastic recoil detection analysis  

Microsoft Academic Search

The trend towards increased fuel burn-up and higher operating temperatures in order to achieve more economic operation of nuclear power plants places demands on a better understanding of oxidative corrosion of Zircaloy (Zry) fuel rod cladding. As part of a programme to study these processes we have applied time-of-flight-energy elastic recoil detection (ToF-E ERD), electrochemical impedance measurements and scanning electron

H. J. Whitlow; Y. Zhang; Y. Wang; T. Winzell; N. Simic; E. Ahlberg; M. Limbäck; G. Wikmark

2000-01-01

267

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

SciTech Connect

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.

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

2004-07-01

268

Coherent-form energy conservation relation for the elastic scattering of a guided mode in a symmetric scattering system.  

PubMed

We propose a coherent-form energy conservation relation (ECR) that is generally valid for the elastic transmission and reflection of a guided mode in a symmetric scattering system. In contrast with the classical incoherent-form ECR, |?|2 + |?|2?1 with ? and ? denoting the elastic transmission and reflection coefficients of a guided mode, the coherent-form ECR is expressed as |? + ?|?1, which imposes a constraint on a coherent superposition of the transmitted and reflected modes. The coherent-form ECR is rigorously demonstrated and is numerically tested by considering different types of modes in various scattering systems. Further discussions with the scattering matrix formalism indicate that two coherent-form ECRs, |? + ?|?1 and |?-?|?1, along with the classical ECR |?|2 + |?|2?1 constitute a complete description of the energy conservation for the elastic scattering of a guided mode in a symmetric scattering system. The coherent-form ECR provides a common tool in terms of energy transfer for understanding and analyzing the scattering dynamics in currently interested scattering systems. PMID:24104318

Liu, Haitao

2013-10-01

269

Correlation between the structure, energy, and local elastic properties of grain boundaries in metals  

SciTech Connect

The zero-temperature energies and equilibrium volume expansions of point-defect free asymmetrical grain boundaries (GBs) involving the four densest planes in fcc bicrystals (with some higher-index plane on the other side of the interface) have been determined using an embedded-atom-method potential fitted to Au. It is found that the two asymmetrical tilt GBs at the endpoints of the related GB energy vs twist disorientation curves give rise to pronounced energy cusps. As for symmetrical GBs, a practically linear relationship between the GB energy and equilibrium volume expansion is observed. The volume expansion and the destruction of the perfect-crystal stacking at the GB are shown to cause a pronounced local decrease in the resistance toward shear parallel to the GB plane. 21 refs., 5 figs.

Wolf, D.; Kluge, M.; Lutsko, J.

1988-01-01

270

Strong pickup-coupling effect on p+Be10 and Be11 elastic scattering around 40A MeV incident energy  

NASA Astrophysics Data System (ADS)

To explore the nature of the coupling effects on p+Be10 and p+Be11 elastic scattering at incident energies of 39.1A and at 38.4A MeV, respectively, coupled reaction channels (CRC) calculations were performed for the Be10(p,d)Be9 and Be11(p,d)Be10* pickup to the ground state of Be9 and the 5.960 MeV 1- and 6.263 MeV 2- doublet of excited states in Be10 at the corresponding incident energies. We show that within the CRC framework, the coupling effect on the elastic scattering is significant in both cases and produces effective absorption in the entrance channel. This suggests that the use of a fitted p+Be10 optical model potential may lead to too much absorption in the core plus proton interaction in extended coupled discretized continuum channels type of calculations for the p+Be11 system and that coupling to the Be11(p,d)Be10* pickup should be explicitly included in such studies.

Keeley, N.; Lapoux, V.

2008-01-01

271

Strong pickup-coupling effect on p+{sup 10}Be and {sup 11}Be elastic scattering around 40A MeV incident energy  

SciTech Connect

To explore the nature of the coupling effects on p+{sup 10}Be and p+{sup 11}Be elastic scattering at incident energies of 39.1A and at 38.4A MeV, respectively, coupled reaction channels (CRC) calculations were performed for the {sup 10}Be(p,d){sup 9}Be and {sup 11}Be(p,d){sup 10}Be* pickup to the ground state of {sup 9}Be and the 5.960 MeV 1{sup -} and 6.263 MeV 2{sup -} doublet of excited states in {sup 10}Be at the corresponding incident energies. We show that within the CRC framework, the coupling effect on the elastic scattering is significant in both cases and produces effective absorption in the entrance channel. This suggests that the use of a fitted p+{sup 10}Be optical model potential may lead to too much absorption in the core plus proton interaction in extended coupled discretized continuum channels type of calculations for the p+{sup 11}Be system and that coupling to the {sup 11}Be(p,d){sup 10}Be* pickup should be explicitly included in such studies.

Keeley, N.; Lapoux, V. [CEA/DSM/DAPNIA/SPhN Saclay, F-91191 Gif-sur-Yvette Cedex (France)

2008-01-15

272

Transient receptor potential channels and energy homeostasis.  

PubMed

Transient receptor potential (TRP) channels are members of an ancient class of ion channels that are present in most mammalian tissues. Consistent with their wide tissue distribution, TRPs are capable of influencing diverse physiological processes including adipocyte function, energy intake and energy expenditure. TRPs function as transduction channels downstream of G-protein-coupled receptors (GPCRs) and receptor tyrosine kinases, and some can also be direct sensors of chemical irritants that influence food intake or regulate body temperature and thermogenesis. TRP agonists were shown to reduce body weight and adiposity, suggesting that they might be exploited as therapeutic targets. In this review I discuss the current knowledge of how TRP channels influence energy balance. PMID:23891326

Ahern, Gerard P

2013-07-24

273

Radial sensitivity of elastic scattering  

SciTech Connect

A new technique has been developed, employing a localized perturbation of the radial nuclear optical potential, which permits direct investigation of the sensitivities of optical model analysis of elastic scattering data to the details of the radial potential. It is found that both light- and heavy-ion scattering probe primarily the nuclear surface region. Higher energy scattering data probe further into the interior than lower energy data. The value of the potential at the center of the nucleus cannot be determined, but only inferred if a fixed parametrization such as Woods-Saxon geometry is specified. In addition, it is found that the region of radial sensitivity of the imaginary potential is systematically closer to the center of the nucleus than is that of the real potential.

Cramer, J.G.; DeVries, R.M.

1980-07-01

274

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

NASA Astrophysics Data System (ADS)

Laboratory and field data indicate that rocks subjected to sufficiently high loads clearly deviate from linear behavior. Non-linear stress-strain relations can be approximated by including third and higher-order terms of the strain tensor in the elastic energy expression (e.g., the Murnaghan model). Such classical non-linear models are successful for calculating deformation of soft materials, for example graphite, but cannot explain with the same elastic moduli small and large non-linear deformation of stiff rocks, such as granite. The values of the third (higher-order) Murnaghan moduli estimated from acoustic experiments are one to two orders of magnitude above the values estimated from stress-strain relations in quasi-static rock-mechanics experiments. The Murnaghan model also fails to reproduce an abrupt change in the elastic moduli upon stress reversal from compression to tension, observed in laboratory experiments with rocks, concrete, and composite brittle material samples, and it predicts macroscopic failure at stress levels lower than observations associated with granite. An alternative energy function based on second-order dependency on the strain tensor, as in the Hookean framework, but with an additional non-analytical term, can account for the abrupt change in the effective elastic moduli upon stress reversal, and extended pre-yielding deformation regime with one set of elastic moduli. We show that the non-analytical second-order model is a generalization of other non-classical non-linear models, for example "bi-linear", "clapping non-linearity", and "unilateral damage" models. These models were designed to explain the abrupt changes of elastic moduli and non-linearity of stiff rocks under small strains. The present model produces dilation under shear loading and other non-linear deformation features of the stiff rocks mentioned above, and extends the results to account for gradual closure of an arbitrary distribution of initial cracks. The results provide a quantitative framework that can be used to model simultaneously, with a small number of coefficients, multiple observed aspects of non-linear deformation of stiff rocks. These include, in addition to the features mentioned above, stress-induced anisotropy and non-linear effects in resonance experiments with damaged materials.

Hamiel, Yariv; Lyakhovsky, Vladimir; Ben-Zion, Yehuda

2011-12-01

275

Relativistic and Close-Coupling Effects in the Spin Polarization of Low-Energy Electrons Scattered Elastically from Cadmium  

NASA Astrophysics Data System (ADS)

The measurements of the Sherman function in elastic electron-cadmium scattering by Bartsch et al. [J. Phys. BJPAPEH0953-4075 25, 1511 (1992)10.1088/0953-4075/25/7/021] have been in serious disagreement with scattering theories for nearly two decades. The recently developed relativistic convergent close-coupling method is applied to the problem and found to be in excellent agreement with experiment over the complete energy range measured. The unusually rapid variation in the spin asymmetry parameter in the vicinity of 4 eV projectile energy is now explained in terms of unitarity of the close-coupling formalism.

Bostock, Christopher J.; Berrington, Michael J.; Fursa, Dmitry V.; Bray, Igor

2011-08-01

276

Dynamics of oxygen in the YBa2Cu3O7-x basal planes by elastic-energy-loss measurements  

Microsoft Academic Search

We report elastic-energy-dissipation measurements in YBa2Cu3O7-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.

G. Cannelli; R. Cantelli; F. Cordero; M. Ferretti; L. Verdini

1990-01-01

277

Relativistic and close-coupling effects in the spin polarization of low-energy electrons scattered elastically from cadmium.  

PubMed

The measurements of the Sherman function in elastic electron-cadmium scattering by Bartsch et al. [J. Phys. B 25, 1511 (1992)] have been in serious disagreement with scattering theories for nearly two decades. The recently developed relativistic convergent close-coupling method is applied to the problem and found to be in excellent agreement with experiment over the complete energy range measured. The unusually rapid variation in the spin asymmetry parameter in the vicinity of 4 eV projectile energy is now explained in terms of unitarity of the close-coupling formalism. PMID:21929240

Bostock, Christopher J; Berrington, Michael J; Fursa, Dmitry V; Bray, Igor

2011-08-23

278

Low-energy elastic electron scattering by tetrafluoromethane (CF[sub 4])  

SciTech Connect

We report cross sections for electronically elastic electron scattering by CF[sub 4] 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.

Winstead, C.; Sun, Q.; McKoy, V. (A. A. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States))

1993-01-15

279

Dressing effects on elastic collisions in dusty plasmas.  

PubMed

Elastic collisions between two dressed grains charged with the same sign in dusty plasmas are investigated using the first- and second-order eikonal method. An interaction potential model taking into account the cross terms of shield effects is applied to describe the interaction potential between dressed dust grains in dusty plasmas. The impact parameter method is applied to investigate the variation of the eikonal phase and elastic cross section as functions of dust charge, Debye length, and collision energy. The result shows that the potential well in the interaction potential plays an important role in the elastic cross section as well as in the eikonal phase. It is also found that the dressing effects significantly increase the elastic cross section and change the sign of the eikonal phase. It is also found that the second-order eikonal phase is caused by the pure plasma screening effects. PMID:12241296

Jung, Young-Dae; Kim, Sung-Soo

2002-08-16

280

California's biomass and its energy potential  

SciTech Connect

The potentials for using California's biomass for energy have been assessed. The study relies on the recent work of Amory Lovins and Lawrence Berkeley Laboratory's (LBL) Distributed Energy System's Project to specify an energy future for Californians. These works identify transportation fuels as the most valuable energy conversion for biomass. Within this context, the extent of five categories of terrestial biomass is estimated, in addition to the environmental impacts and monetary cost of collecting and transporting each biomass category. Estimates of the costs of transforming biomass into different fuels as well as a survey of government's role in a biomass energy program are presented. The major findings are summarized below. (1) California's existing biomass resources are sufficient to provide only 20 percent of its future liquid fuel requirements. (2) Meeting the full transportation demand with biomass derived fuels will require the development of exotic biomass sources such as kelp farms and significant reductions in automobile travel in the State. (3) Under assumptions of moderate increases in gasoline prices and without major new government incentives, the cost of transforming biomass into transport fuels will be competitive with the price of gasoline on a Btu basis by the year 1990. (4) The environmental impacts of collecting most forms of biomass are beneficial and should reduce air pollution from agricultural burning and water pollution from feedlot and dairy farm runoff. Moreover, the collection of logging residues should improve timber stand productivity and the harvest of chaparral should reduce the risk of wildfire in the State. (5) The institutional context for implementing biomass energy projects is complex and fragmented.

Lucarelli, F.B. Jr.

1980-04-01

281

Elasticity theory of smectic and canonic mesophases  

SciTech Connect

The general theory of elasticity for smectic and canonic mesophases is formulated, starting from the assumption that the equilibrium state is spatially periodic. The various surface terms appearing in the deformation free energy density are considered as well. The effective description of the elastic behavior of a general nonchiral smectic mesophase involves one positional elastic constant, 16 bulk orientational elastic constants, and six surface orientational elastic constants. One additional bulk orientational elastic constant is required for the description of a general chiral smectic mesophase. The effective description of the elastic behavior of a general nonchiral canonic mesophase involves six positional elastic constants and three bulk orientational elastic constants. In this case the property of chirality does not introduce additional orientational elastic constants. The elastic constants for some relevant smectic and canonic mesophases are given, including the elastic constants for the antiferroelectric Sm-[ital C][sub [ital A

Stallinga, S.; Vertogen, G. (Institute for Theoretical Physics, University of Nijmegen Toernooiveld, 6525 ED Nijmegen (Netherlands))

1995-01-01

282

The Elastic Energy Balance within Periodic, Chaotic and Localized Slip Pulse Solutions with Dieterich-Ruina Friction  

NASA Astrophysics Data System (ADS)

We investigate the emergent dynamics when the nonlinear Dieterich-Ruina rate and state friction law is attached to a Burridge-Knopoff spring-block model. We derive both the discrete and continuous equations governing the system in this framework. The discrete system (ODEs) exhibits both periodic and chaotic motion, where the system's transition to chaos is size-dependent, i.e. how many blocks are considered. When the system of blocks is in the chaotic regime, we are interested in studying how the elastic energy of the spring connecting the moving plate to the block is transferred into the elastic energy stored in the springs interconnecting the blocks. The elastic energy travels from one spring to the others via the kinetic energy minus energy lost because of the friction law. The question is how the nonlinear friction law affects this transfer of energy as a function of time. From the discrete model we derive the nonlinear elastic wave equation by taking the continuum limit. This results in a nonlinear partial differential equation (PDE) and we find that both temporal and spatial chaos ensues when the same parameter is increased. This critical parameter value needed for the onset of chaos in the continuous model is much smaller than the value needed in the case of a single block and we discuss the implications this has on dynamic modeling with this specific friction law. Most importantly, these results suggest that the friction law is scale-dependent, thus caution should be taken when attaching a friction law derived at laboratory scales to full-scale earthquake rupture models. Furthermore, we find solutions where the initial slip pulse propagates like a traveling wave, or remains localized in space, suggesting the presence of soliton and breather solutions. In the case of a traveling wave we see evidence of a soliton, a wave with permanent form, that is localized in space while it travels at a constant speed through the medium. The breather solution is a time-periodic, exponentially decaying (in space) solution of a nonlinear wave equation. We discuss the significance of these pulse-like solutions and how they can be understood as a proxy for the propagation of the rupture front across the fault surface during an earthquake. We compute analytically the conditions for soliton solutions and by exploring the resulting parameter space, we may determine a range for suitable parameter values to be used in dynamic earthquake modeling.

Erickson, B. A.; Birnir, B.; Lavallee, D.; Madariaga, R. I.

2010-12-01

283

The {sup 6}He Optical Potential at energies around the Coulomb barrier  

SciTech Connect

We present an Optical Model (OM) study of {sup 6}He on {sup 208}Pb elastic scattering data, measured at laboratory energies around the Coulomb barrier (E{sub lab} = 14, 16, 18, 22, and 27 MeV)[1]. For the projectile-target bare interaction, we use the microscopic Sao Paulo Potential (SPP). This bare interaction is supplemented with a Coulomb Dipole Polarization (CDP) potential, as well as a diffuse complex Woods-Saxon potential. Four-body Continuum-Discretized-Coupled-Channels (CDCC) calculations have been performed in order to support the optical model analysis. We have also studied the alpha channel, which is the dominant reaction process. In the analysis of this channel, we compare the angular and energy distributions of the alpha particles measured at 22 MeV, with Distorted Wave Born Approximation (DWBA) calculations.

Fernandez-Garcia, J. P.; Alvarez, M. A. G. [Dpto. de FAMN, Universidad de Sevilla, Apdo. 1065, 41080 Sevilla (Spain); CNA, Universidad de Sevilla, c/Thomas Alva Edison 7, 41092 Sevilla (Spain); Rodriguez-Gallardo, M. [Dpto. de FAMN, Universidad de Sevilla, Apdo. 1065, 41080 Sevilla (Spain); Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain); Moro, A. M. [Dpto. de FAMN, Universidad de Sevilla, Apdo. 1065, 41080 Sevilla (Spain)

2010-04-26

284

Some Convergence Tests on Medium Energy Pion-Deuteron Elastic Scattering Amplitudes.  

National Technical Information Service (NTIS)

With the exact solution of a covariant multiple scattering model for elastic pion deuteron scattering as a standard, the convergence of the multiple scattering series and the sufficiency of the first order and on-shell second order scattering amplitudes a...

A. S. Rinat Y. Starkand

1979-01-01

285

Elastic pp Scattering at LHC Energies in Various Multi-Pomeron Exchange Models  

NASA Astrophysics Data System (ADS)

We consider the data for elastic pp scattering in the framework of Regge theory in various models of multiple Pomeron exchanges: quasi-eikonal approach and two-channel approach. The results of the model calculations are compared with the experimental data presented by the TOTEM collaboration.

Novikov, Ivan; Shabelski, Yuli

2012-10-01

286

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

SciTech Connect

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.

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

287

Potential and Kinetic Energy - What's it all about?  

Microsoft Academic Search

Our investigation deals with the difference between kinetic and potential energy, and different situations that model those energies. Students needed to define kinetic and potential energy. In addition they needed to discover what the equations are to calculate these energies. Students were to investigate different situations where these energies are evident using various modeling technologies and design a tangible model

Fayne Winter; Larry Bedgood; Susan Cooper

2005-01-01

288

Recent developments in quasi-elastic scattering around the Coulomb barrier  

SciTech Connect

We discuss two recent topics on heavy-ion quasi-elastic scattering at energies around the Coulomb barrier. The first topic is an application of quasi-elastic scattering at deep-subbarrier energies to extracting the surface diffuseness parameter of the nucleus-nucleus potential. The second topic is a coupled-channels analysis for the quasi-elastic barrier distribution for the 70Zn + 208Pb reaction. We show that the coupled-channels calculations which include the multi-phonon excitations in the colliding nuclei reproduce reasonably well the experimental excitation function for quasi-elastic scattering at backward angles and the barrier distribution for this reaction.

Hagino, K. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

2007-02-26

289

Rapid Hydrogel Microactuator Using Elastic Instability  

NASA Astrophysics Data System (ADS)

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)

Lee, Howon; Xia, Chunguang; Fang, Nicholas

2009-03-01

290

Energy potential of sugarcane and sweet sorghum  

SciTech Connect

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.

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

1980-01-01

291

Design guidance for elastic followup  

SciTech Connect

The basic mechanism of elastic followup is discussed in relation to piping design. It is shown how mechanistic insight gained from solutions for a two-bar problem can be used to identify dominant design parameters and to determine appropriate modifications where elastic followup is a potential problem. It is generally recognized that quantitative criteria are needed for elastic followup in the creep range where badly unbalanced lines can pose potential problems. Approaches for criteria development are discussed.

Naugle, F.V.

1983-01-01

292

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

Microsoft Academic Search

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

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

2006-01-01

293

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)  

NASA Astrophysics Data System (ADS)

Recently [S. Magazù 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.

Magazù, Salvatore; Migliardo, Federica; Benedetto, Antonio

2012-10-01

294

Mechanism of Resilin Elasticity  

PubMed Central

Resilin is critical in the flight and jumping systems of insects as a polymeric rubber-like protein with outstanding elasticity. However, insight into the underlying molecular mechanisms responsible for resilin elasticity remains undefined. Here we report the structure and function of resilin from Drosophila CG15920. A reversible beta-turn transition was identified in the peptide encoded by exon III and for full length resilin during energy input and release, features that correlate to the rapid deformation of resilin during functions in vivo. Micellar structures and nano-porous patterns formed after beta-turn structures were present via changes in either the thermal or mechanical inputs. A model is proposed to explain the super elasticity and energy conversion mechanisms of resilin, providing important insight into structure-function relationships for this protein. Further, this model offers a view of elastomeric proteins in general where beta-turn related structures serve as fundamental units of the structure and elasticity.

Qin, Guokui; Hu, Xiao; Cebe, Peggy; Kaplan, David L.

2012-01-01

295

Size dependent stability analysis of circular ultrathin films in elastic medium with consideration of surface energies  

NASA Astrophysics Data System (ADS)

In this article, analytical framework is developed for size dependent symmetric stability and self-instability of circular nanoplates including surface effects using modified Kirchhoff plate theory. The surrounding elastic medium is modeled as Winkler elastic foundation and its effect is comprehensively studied on self-instability problems. The derived explicit solutions contain Bessel functions with modified arguments reflecting the size dependency of the buckling loads. In order to check the results an inverse formulation is presented for effective Young's modulus using the buckling loads to be verified by previous experimental results for nanowires. Several numerical examples are given for two types of materials with positive and negative surface properties to show the general trends of size dependencies. Some problems and limitations are explored for consistency of results with experiments and suggestions for future works.

Assadi, Abbas; Farshi, Behrooz

2011-03-01

296

An ab initio method for locating potential energy minima  

SciTech Connect

We study the potential energy landscape underlying the motion of monatomic liquids by quenching from random initial configurations (stochastic configurations) to the nearest local minimum of the potential energy. We show that this procedure reveals the underlying potential energy surface directly. This is in contrast to the common technique of quenching from a molecular dynamics trajectory which does not allow a direct view of the underlying potential energy surface, but needs to be corrected for thermodynamic weighting factors.

Bock, Nicolas [Los Alamos National Laboratory; Peery, Travis [Los Alamos National Laboratory; Venneri, Giulia [Los Alamos National Laboratory; Chisolm, Eric [Los Alamos National Laboratory; Wallace, Duane [Los Alamos National Laboratory; Lizarraga, Raquel [CHILE; Holmstrom, Erik [CHILE

2009-01-01

297

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

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}

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

298

Effect of high-energy X-ray doses on bone elastic properties and residual strains.  

PubMed

Bone X-ray irradiation occurs during medical treatments, sterilization of allografts, space travel and in vitro studies. High doses are known to affect the post-yield properties of bone, but their effect on the bone elastic properties is unclear. The effect of such doses on the mineral-organic interface has also not been adequately addressed. Here, the evolution of elastic properties and residual strains with increasing synchrotron X-ray dose (5-3880 kGy) is examined on bovine cortical bone. It is found that these doses affect neither the degree of nanometer-level load transfer between the hydroxyapatite (HAP) platelets and the collagen up to stresses of -60 MPa nor the microscopic modulus of collagen fibrils (both measured by synchrotron X-ray scattering during repeated in situ loading and unloading). However, the residual elastic strains in the HAP phase decrease markedly with increased irradiation, indicating damage at the HAP-collagen interface. The HAP residual strain also decreases after repeated loading/unloading cycles. These observations can be explained by temporary de-bonding at the HAP/collagen interface (thus reducing the residual strain), followed by rapid re-bonding (so that load transfer capability is not affected). PMID:22098877

Singhal, A; Deymier-Black, Alix C; Almer, J D; Dunand, D C

2011-06-21

299

Mean potential energy change in stratified grid turbulence  

Microsoft Academic Search

Laboratory experiments are used to study the effect of stratification and molecular diffusiv- ity on the mean potential energy change due to grid turbulence in a linearly stratified fluid. Two quantities that characterize the potential energy change are the mixing efficiency, defined as the ratio of the mean potential energy change and the work done by the grid on the

Chris R. Rehmanna; Jeffrey R. Koseff

300

Energy resource potential of natural gas hydrates  

USGS Publications Warehouse

The discovery of large gas hydrate accumulations in terrestrial permafrost regions of the Arctic and beneath the sea along the outer continental margins of the world's oceans has heightened interest in gas hydrates as a possible energy resource. However, significant to potentially insurmountable technical issues must be resolved before gas hydrates can be considered a viable option for affordable supplies of natural gas. The combined information from Arctic gas hydrate studies shows that, in permafrost regions, gas hydrates may exist at subsurface depths ranging from about 130 to 2000 m. The presence of gas hydrates in offshore continental margins has been inferred mainly from anomalous seismic reflectors, known as bottom-simulating reflectors, that have been mapped at depths below the sea floor ranging from about 100 to 1100 m. Current estimates of the amount of gas in the world's marine and permafrost gas hydrate accumulations are in rough accord at about 20,000 trillion m3. Disagreements over fundamental issues such as the volume of gas stored within delineated gas hydrate accumulations and the concentration of gas hydrates within hydrate-bearing strata have demonstrated that we know little about gas hydrates. Recently, however, several countries, including Japan, India, and the United States, have launched ambitious national projects to further examine the resource potential of gas hydrates. These projects may help answer key questions dealing with the properties of gas hydrate reservoirs, the design of production systems, and, most important, the costs and economics of gas hydrate production.

Collett, T. S.

2002-01-01

301

Thermophotovoltaic energy conversion: Technology and market potential  

NASA Astrophysics Data System (ADS)

This report contains material displayed on poster panels during the Conference. The purpose of the contribution was to present a summary of the business overview of thermophotovoltaic generation of electricity and its market potential. The market analysis has shown that the TPV market, while currently still in an early nucleation phase, is evolving into a range of small niche markets out of which larger-size opportunities can emerge. Early commercial applications on yachts and recreational vehicles which require a quiet and emission-free compact electrical generator fit the current TPV technology and economics. Follow-on residential applications are attractive since they can combine generation of electricity with space and hot water heating in a co-generation system. Development of future markets in transportation, both private and communal or industrial, will be driven by legislation requiring emission-free vehicles, and by a reduction in TPV systems cost. As a result of ``moving down the learning curve,'' growing power and consumer markets are predicted to come into reach of TPV systems, a development favored by high overall energy conversion efficiency due to high radiation energy density and to high electric conversion efficiency available with photovoltaic cells.

Ostrowski, Leon J.; Pernisz, Udo C.; Fraas, Lewis M.

1996-02-01

302

Ab initio potential energy surfaces and nonadiabatic collision dynamics in H++O2 system  

NASA Astrophysics Data System (ADS)

The adiabatic potential energy surfaces for the lowest five electronic states of 3A'' symmetry for the H++O2 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 3A'' and 2 3A''), which adiabatically correlate in the asymptotic limit to H(2S)+O2+(X 2?g) and H++O2(X 3?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 O2 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 O2 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.

Amaran, Saieswari; Kumar, Sanjay

2008-04-01

303

The high potential of wind as an energy source  

Microsoft Academic Search

A recently completed ERDA study shows that the full potential of wind as an energy source is far greater than previously estimated. The paper reviews various aspects of wind energy including wind energy resources, conversion systems, wind turbine applications, and the national potential for wind energy.

U. Coty; M. Dubey

1976-01-01

304

On the global and regional potential of renewable energy sources  

Microsoft Academic Search

In this thesis, the central research question is: what can be the contribution of renewable energy sources to the present and future world and regional energy supply system. The focus is on wind, solar PV and biomass energy (energy crops) for electricity generation. For the assessment of the economic potential, we construct cost-supply curves. As the economic potential also depends

Monique Maria Hoogwijk

2004-01-01

305

Potential Analysis of Wind Energy as a Power Generation Source  

Microsoft Academic Search

Wind energy as a power generation source is one of the most significant and rapidly developing renewable energy sources in the world. Because wind energy potential in various parts of Turkey is becoming economical, it is necessary to determine to start the immediate usage of the wind energy potential and the investigation of the necessary techniques and economic feasibility. In

M. Kurban; F. O. Hocaoglu

2009-01-01

306

Potential and Kinetic Energy; "To Move or not to Move".  

NSDL National Science Digital Library

Students will investigate, through a guided exploration lab, using a tennis ball, the Law of Conservation of Energy to differentiate between Potential and Kinetic Energy, and identify real life situations where potential energy is transformed into kinetic energy and vice versa.

Sherdan, Danielle

2010-05-13

307

Energy dependence of phenomenological optical model potentials for the 7Li+11B reaction  

NASA Astrophysics Data System (ADS)

Angular distributions of 7Li+11B elastic scattering were measured at Elab(7Li)=9.85, 13.3, 18.3, 23.3, and 28.3 MeV within the angular range of ?c.m.?15?-80?. Optical model potentials have been extracted from these angular distributions and the data available in the literature at Elab(7Li)=34 MeV and Elab(11B)=44 MeV to study the gross influences of intricate coupling effects varying with the reaction energy. With fixed geometrical shapes, the strengths of both real and imaginary potentials show a linear decrease with increasing energy, which is different from previous observations.

Yang, L.; Lin, C. J.; Jia, H. M.; Xu, X. X.; Yang, F.; Zhang, H. Q.; Liu, Z. H.; Bao, P. F.; Sun, L. J.

2013-04-01

308

Static task of von Mises planar truss analyzed using the potential energy  

NASA Astrophysics Data System (ADS)

A Von Mises planar truss subjected to vertical static load at its top joint is studied. The mathematical concept of large displacement elastic analysis of the von Mises truss targeted for computers is described. The model geometry is described using finite mass points. Formulae for the evaluation of displacements of mass points and rotation of segments were derived with the help of geometrical and physical conditions. Formulae for the determination of potential energy of the system are listed. Deformation of the structure is evaluated by seeking the minimal potential energy. The step-by-step increment method combined with Newton-Raphson method is used. The mathematical solution described in the article enables the modelling of Mises truss using a finite amount of segments. The described solution is suitable for load-deflection curve computation of a limit load model. The equilibrium stability problem of von Mises truss is discussed in connection with the random effects of imperfections.

Kalina, Martin

2013-10-01

309

Renewable energy resources in Pakistan: status, potential and information systems.  

National Technical Information Service (NTIS)

This paper provides some details regarding the characteristic properties, potential and assessment of renewable energy compared with other forms of energy sources. It gives status of renewable energy sources in Pakistan. It also lights about the agencies ...

A. M. Khan

1991-01-01

310

Elastic collisions of low-energy electrons with SiY4 (Y = Cl, Br, I) molecules  

NASA Astrophysics Data System (ADS)

We employed the Schwinger multichannel method to compute elastic integral, differential, and momentum transfer cross sections for low-energy electron collisions with SiY4 (Y = Cl, Br, I) molecules. The calculations were carried out in the static-exchange and static-exchange plus polarization approximations for energies up to 10 eV. The elastic integral cross section for SiCl4 and SiBr4, computed in the static-exchange plus polarization approximation, shows two shape resonances belonging to the T2 and E symmetries of the Td group, and for SiI4 shows one shape resonance belonging to the E symmetry of the Td group. The present results agree well in shape with experimental total cross sections. The positions of the resonances observed in the calculated integral cross sections are also in agreement with the experimental positions. We have found the presence of a virtual state for SiCl4 and a Ramsauer-Townsend minimum for SiI4 at 0.5 eV. The present results show that the proper inclusion of polarization effects is crucial in order to correctly describe the resonance spectra of these molecules and also to identify a Ramsauer-Townsend minimum for SiI4 and a virtual state for SiCl4.

Bettega, M. H. F.

2011-11-01

311

Elastic collisions of low-energy electrons with SiY{sub 4} (Y = Cl, Br, I) molecules  

SciTech Connect

We employed the Schwinger multichannel method to compute elastic integral, differential, and momentum transfer cross sections for low-energy electron collisions with SiY{sub 4} (Y = Cl, Br, I) molecules. The calculations were carried out in the static-exchange and static-exchange plus polarization approximations for energies up to 10 eV. The elastic integral cross section for SiCl{sub 4} and SiBr{sub 4}, computed in the static-exchange plus polarization approximation, shows two shape resonances belonging to the T{sub 2} and E symmetries of the T{sub d} group, and for SiI{sub 4} shows one shape resonance belonging to the E symmetry of the T{sub d} group. The present results agree well in shape with experimental total cross sections. The positions of the resonances observed in the calculated integral cross sections are also in agreement with the experimental positions. We have found the presence of a virtual state for SiCl{sub 4} and a Ramsauer-Townsend minimum for SiI{sub 4} at 0.5 eV. The present results show that the proper inclusion of polarization effects is crucial in order to correctly describe the resonance spectra of these molecules and also to identify a Ramsauer-Townsend minimum for SiI{sub 4} and a virtual state for SiCl{sub 4}.

Bettega, M. H. F. [Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19044, 81531-990 Curitiba, Parana (Brazil)

2011-11-15

312

Transiting the molecular potential energy surface along low energy pathways: The TRREAT algorithm.  

PubMed

The Transition Rapidly exploring Random Eigenvector Assisted Tree (TRREAT) algorithm is introduced to perform searches along low curvature pathways on a potential energy surface (PES). The method combines local curvature information about the PES with an iterative Rapidly exploring Random Tree algorithm (LaValle, Computer Science Department, Iowa State University, 1998, TR98-11) that quickly searches high-dimensional spaces for feasible pathways between local minima. Herein, the method is applied to identifying conformational changes of molecular systems using Cartesian coordinates while avoiding a priori definition of collective variables. We analyze the pathway identification problem for alanine dipeptide, cyclohexane and glycine using nonreactive and reactive forcefields. We show how TRREAT-identified pathways can be used as valuable input guesses for double-ended methods such as the Nudged Elastic Band when ascertaining transition state energies. This method can be utilized to improve/extend the reaction databases that lie at the core of automatic chemical reaction mechanism generator software currently developed to build kinetic models of chemical reactions. © 2013 Wiley Periodicals, Inc. PMID:24018749

Campañá, Carlos; Miller, Ronald E

2013-09-05

313

Energy distribution between seismic waves of different types produced in an elastic half-space by a source with an arbitrary radiation pattern  

Microsoft Academic Search

The energy distribution between different types of seismic waves produced by a source of longitudinal and transverse waves with an arbitrary radiation pattern in an elastic half-space is considered. With an appropriate choice of the angular distribution functions, this source can model an earthquake source. A direct theoretical comparison of the energy distributions of seismic waves generated by an underground

G. A. Maximov; M. E. Merkulov; V. Yu. Kudryavtsev

2003-01-01

314

Search for rapid angular and energy dependence of dsigma/d. cap omega. and iT/sub 11/ in large angle. pi. -d elastic scattering  

SciTech Connect

The ..pi..-d elastic differential cross-section and the vector analyzing power have been measured between CTHETA/sub c.m./ = 95/sup 0/ and 165/sup 0/ at incident pion energies between 117 and 151 MeV. Both observables show a smooth behavior as a function of angle and energy.

Mathie, E.L.; Smith, G.R.; Boschitz, E.T.; Meyer, M.; Vogler, F.; Daum, M.; Mango, S.; Konter, J.A.

1983-12-01

315

Release of elastic strain energy as acoustic emission during the reverse thermoelastic phase transformation in Au-47. 5 at. % Cd alloy  

SciTech Connect

This paper presents experimental evidence concerning the acoustic energy evolved during the heating and cooling phase changes in Au-47.5 at. % Cd polycrystals. Results are examined from the point of view of the stored elastic strain energy during the martensite formation, and the frictional work that is dissipated by the movement of martensite interfaces in either direction, upon heating and cooling.

Baram, J. (Ben Gurion Univ., Beer Sheva, Israel); Avissar, J.; Gefen, Y.; Rosen, M.

1980-09-01

316

Spatial mapping of renewable energy potential  

Microsoft Academic Search

An energy resource that is renewed by nature and whose supply is not affected by the rate of consumption is often termed as renewable energy. The need to search for renewable, alternate and non-polluting sources of energy assumes top priority for self-reliance in the regional energy supply. This demands an estimation of available energy resources spatially to evolve better management

T. V. Ramachandraa

317

Biomass resource potential using energy crops.  

National Technical Information Service (NTIS)

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 cr...

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

1993-01-01

318

Multichannel quantum defect theory for cold molecular collisions with a strongly anisotropic potential energy surface  

NASA Astrophysics Data System (ADS)

We show that multichannel quantum defect theory (MQDT) can be applied successfully as an efficient computational method for cold molecular collisions in Li+NH, which has a deep and strongly anisotropic interaction potential. In this strongly coupled system, closed-channel poles restrict the range over which the MQDT Y can be interpolated. We present an improved procedure to transform the MQDT reference functions so that the poles are removed from the energy range of interest. Effects due to very-long-range spin dipolar couplings are outside the scope of MQDT, but can be added perturbatively. This procedure makes it possible to calculate the elastic and inelastic cross sections, over the entire range of energies and fields needed to evaluate the feasibility of sympathetic cooling of NH by Li, using coupled-channel calculations at only five combinations of energy and field.

Croft, James F. E.; Hutson, Jeremy M.

2013-03-01

319

Biomass resource potential using energy crops  

Microsoft Academic Search

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

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

1993-01-01

320

Potential for energy conservation in Montana  

Microsoft Academic Search

A brief review of the status of national, regional, and state energy policies is made. The possibility of energy conservation in all sectors is cited and in the state of Montana, the state government has powers to promote energy conservation that include utilities regulation, land use control, tax incentives or disincentives, police power (such as rationing), and education. An energy

1973-01-01

321

Transportation Energy Use and Conservation Potential  

ERIC Educational Resources Information Center

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)

Hirst, Eric

1973-01-01

322

Re-examining Potential for Geothermal Energy in United States  

Microsoft Academic Search

New technological initiatives, along with potential policy and economic incentives, could help to bring about a resurgence in geothermal energy development in the United States, said several experts at a 22 May forum in Washington, D.C. The forum was sponsored by the House and Senate Renewable Energy and Energy Efficiency Caucuses, the Sustainable Energy Coalition, and the Environmental and Energy

Randy Showstack

2003-01-01

323

Potential contribution of biomass to the sustainable energy development  

Microsoft Academic Search

Biomass is a renewable energy source and its importance will increase as national energy policy and strategy focuses more heavily on renewable sources and conservation. Biomass is considered the renewable energy source with the highest potential to contribute to the energy needs of modern society for both the industrialized and developing countries worldwide. The most important biomass energy sources are

M. Fatih Demirbas; Mustafa Balat; Havva Balat

2009-01-01

324

Regional Differences in the Price-Elasticity of Demand for Energy.  

National Technical Information Service (NTIS)

At the request of the National Renewable Energy Laboratory (NREL), the RAND Corporation examined the relationship between energy demand and energy prices with the focus on whether the relationships between demand and price differ if these are examined at ...

M. A. Bernstein J. Griffin

2006-01-01

325

Domestic Potential of Solar and Other Renewable Energy Sources.  

National Technical Information Service (NTIS)

This is a study of the present and potential use in the United States of the renewable energy resources generally included under the term solar energy. In particular, the study attempts to estimate the likely energy costs and potential market penetrations...

1979-01-01

326

Biomass energy: the scale of the potential resource  

Microsoft Academic Search

Increased production of biomass for energy has the potential to offset substantial use of fossil fuels, but it also has the potential to threaten conservation areas, pollute water resources and decrease food security. The net effect of biomass energy agriculture on climate could be eithercoolingor warming, depending on the crop,the technology for converting biomass into useable energy, and the difference

B. Field; J. Elliott Campbell; David B. Lobell

2007-01-01

327

Simulation of 12C+12C elastic scattering at high energy by using the Monte Carlo method  

NASA Astrophysics Data System (ADS)

The Monte Carlo method is used to simulate the 12C+12C reaction process. Taking into account the size of the incident 12C beam spot and the thickness of the 12C target, the distributions of scattered 12C on the MWPC and the CsI detectors at a detective distance have been simulated. In order to separate elastic scattering from the inelastic scattering with 4.4 MeV excited energy, we set several variables: the kinetic energy of incident 12C, the thickness of the 12C target, the ratio of the excited state, the wire spacing of the MWPC, the energy resolution of the CsI detector and the time resolution of the plastic scintillator. From the simulation results, the preliminary establishment of the experiment system can be determined to be that the beam size of the incident 12C is phi5 mm, the incident kinetic energy is 200-400 A MeV, the target thickness is 2 mm, the ratio of the excited state is 20%, the flight distance of scattered 12C is 3 m, the energy resolution of the CsI detectors is 1%, the time resolution of the plastic scintillator is 0.5%, and the size of the CsI detectors is 7 cm×7 cm, and we need at least 16 CsI detectors to cover a 0° to 5° angular distribution.

Guo, Chen-Lei; Zhang, Gao-Long; Tanihata, I.; Le, Xiao-Yun

2012-03-01

328

Microscopic self-energy calculations and dispersive optical-model potentials  

SciTech Connect

Nucleon self-energies for {sup 40,48,60}Ca isotopes are generated with the microscopic Faddeev-random-phase approximation (FRPA). These self-energies are compared with potentials from the dispersive optical model (DOM) that were obtained from fitting elastic-scattering and bound-state data for {sup 40,48}Ca. The ab initio FRPA is capable of explaining many features of the empirical DOM potentials including their nucleon asymmetry dependence. The comparison furthermore provides several suggestions to improve the functional form of the DOM potentials, including among others the exploration of parity and angular momentum dependence. The nonlocality of the FRPA imaginary self-energy, illustrated by a substantial orbital angular momentum dependence, suggests that future DOM fits should consider this feature explicitly. The roles of the nucleon-nucleon tensor force and charge-exchange component in generating the asymmetry dependence of the FRPA self-energies are explored. The global features of the FRPA self-energies are not strongly dependent on the choice of realistic nucleon-nucleon interactions.

Waldecker, S. J.; Dickhoff, W. H. [Department of Physics, Washington University, St. Louis, Missouri 63130 (United States); Barbieri, C. [Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Theoretical Nuclear Physics Laboratory, RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

2011-09-15

329

Atomistic calculations of interface elastic properties in noncoherent metallic bilayers  

SciTech Connect

The paper describes theoretical and computational studies associated with the interface elastic properties of noncoherent metallic bicrystals. Analytical forms of interface energy, interface stresses, and interface elastic constants are derived in terms of interatomic potential functions. Embedded-atom method potentials are then incorporated into the model to compute these excess thermodynamics variables, using energy minimization in a parallel computing environment. The proposed model is validated by calculating surface thermodynamic variables and comparing them with preexisting data. Next, the interface elastic properties of several fcc-fcc bicrystals are computed. The excess energies and stresses of interfaces are smaller than those on free surfaces of the same crystal orientations. In addition, no negative values of interface stresses are observed. Current results can be applied to various heterogeneous materials where interfaces assume a prominent role in the systems' mechanical behavior.

Mi Changwen; Jun, Sukky; Kouris, Demitris A.; Kim, Sung Youb [Department of Mechanical Engineering, University of Wyoming, Laramie, Wyoming 82071 (United States); Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309 (United States)

2008-02-15

330

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

NASA Astrophysics Data System (ADS)

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.

Karataglidis, S.; Madland, D. G.

2001-10-01

331

Spin Correlation Parameter Cyy of p + 3He Elastic Backward Scattering at Intermediate Energy  

NASA Astrophysics Data System (ADS)

It is possible to use nucleon-nucleus scattering as a probe of the spin structure of nuclei, since target related observables are extremely sensitive to small spin-dependent parts of the target wave function. In addition, one can gain information about the nucleon-nucleus reaction mechanism, the spin dependence of the nucleon-nucleon interaction in the nuclear medium, and off-shell behavior of the nucleon-nucleon amplitudes. For 3He(p,3He)p elastic backward scattering (EBS), only a small amount of data exists for the differential cross-section and none exists for spin-dependent observables. We have developed a spin-exchange polarised 3He target and measured the spin correlation parameter Cyy at 200, 300, and 400 MeV.

Shimizu, Y.; Hatanaka, K.; Adachi, T.; Itoh, K. F. K.; Kawabata, T.; Kudoh, T.; Ohira, H. M. H.; Okamura, H.; Sagara, K.; Sasamoto, Y. S. Y.; Yoshida, Y. S. H. P.; Suda, K.; Tomiyama, Y. T. A. T. M.; Uesaka, M. U. T.; Wakasa, T.; Wakui, T.

2005-08-01

332

Proton-Proton Elastic Scattering Excitation Functions at Intermediate Energies: Cross Sections and Analyzing Powers  

NASA Astrophysics Data System (ADS)

The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH2) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power AN and the polarization correlation parameters ANN, ASS and ASL are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent d?/d? and AN data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.

Hinterberger, F.; Rohdjeß, H.; Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Büßer, K.; Busch, M.; Colberg, T.; Diehl, O.; Dohrmann, F.; Engelhardt, H. P.; Eversheim, P. D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Groß-Hardt, R.; Hinterberger, F.; Jahn, R.; Jonas, E.; Krause, H.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Meinerzhagen, A.; Nähle, O.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; von Rossen, P.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Trelle, H. J.; Weise, E.; Wellinghausen, A.; Woller, K.; Ziegler, R.

2000-01-01

333

Probing elastic and inelastic breakup contributions to intermediate-energy two-proton removal reactions  

NASA Astrophysics Data System (ADS)

The two-proton removal reaction from 28Mg projectiles has been studied at 93 MeV/u. First coincidence measurements of the heavy 26Ne projectile residues, the removed protons, and other light charged particles enabled the relative cross sections from each of the three possible elastic and inelastic proton removal mechanisms to be determined. These more final-state-exclusive measurements are key for further interrogation of these reaction mechanisms and use of the reaction channel for quantitative spectroscopy of very neutron-rich nuclei. The relative and absolute yields of the three contributing mechanisms are compared to reaction model expectations based on the use of eikonal dynamics and sd-shell-model structure amplitudes.

Wimmer, K.; Bazin, D.; Gade, A.; Tostevin, J. A.; Baugher, T.; Chajecki, Z.; Coupland, D.; Famiano, M. A.; Ghosh, T. K.; Grinyer, G. F.; Hodges, R.; Howard, M. E.; Kilburn, M.; Lynch, W. G.; Manning, B.; Meierbachtol, K.; Quarterman, P.; Ratkiewicz, A.; Sanetullaev, A.; Stroberg, S. R.; Tsang, M. B.; Weisshaar, D.; Winkelbauer, J.; Winkler, R.; Youngs, M.

2012-05-01

334

Potential for Energy Conservation Technology Transfer.  

National Technical Information Service (NTIS)

The segment of energy consumption related to space conditioning and water heating in residential, commercial, and institutional buildings is discussed specifically. Within this constraint building energy consumption is discussed, considering three choices...

E. C. Hise

1976-01-01

335

Neutron elastic scattering from 116,118,120,122,124Sn  

NASA Astrophysics Data System (ADS)

Accurate measurements of neutron differential elastic cross sections have been obtained from even isotopes of Sn. Data are presented for the elastic scattering of 11 MeV neutrons from 116, 118, 120, 122, 124Sn, the elastic scattering for 24 MeV neutrons from 116, 118, 124Sn and the neutron total cross section from 118, 120, 122, 124Sn in the energy ranges 5.0-10.6 MeV and 20.0-26.0 MeV. The elastic scattering data are analyzed in terms of an empirical optical-model potential. The obtained optical-potential parameters are analyzed in terms of energy and isospin dependence and compared with those obtained from proton elastic scattering on even Sn isotopes.

Rapaport, J.; Mirzaa, Mohammed; Hadizadeh, H.; Bainum, D. E.; Finlay, R. W.

1980-05-01

336

Simultaneous analysis of elastic, breakup, and fusion channels for 6He induced reactions at energies near the Coulomb barrier  

NASA Astrophysics Data System (ADS)

We present some recent applications of the Continuum-Discretized Coupled-Channels (CDCC) and Coupled-Reaction-Channels (CRC) methods to the study of reactions induced by weakly-bound nuclei on stable targets. The methods are applied to the scattering of the Borromean nucleus 6He at energies around the Coulomb barrier. Elastic scattering data are very well described by four-body CDCC calculations (based on a three-body description of the 6He nucleus) but also by simpler three-body CDCC calculations, using a suitable two-body model for 6He. By contrast, inclusive ? data are better described using the CRC approach, which treats the breakup within the transfer to the continuum picture and, unlike the CDCC method, allows the inclusion of transfer to bound states of the target. We explore also the possibility of calculating the fusion cross sections using the CRC framework.

Moro, A. M.; Fernández-García, J. P.; Alvarez, M. A. G.; Rodríguez-Gallardo, M.

2011-10-01

337

Microscopic study of neutron elastic scattering from {sup 12}C, {sup 40}Ca, and {sup 208}Pb at intermediate energies  

SciTech Connect

Recent neutron elastic scattering differential cross section data for {sup 12}C, {sup 40}Ca, and {sup 208}Pb at several energies from 65 to 225 MeV have been analyzed using Glauber multiple scattering model, suitably modified to enlarge angular range of validity. The center of mass and Pauli pair correlations have been considered. The effect of the phase variation of the NN scattering amplitude on the calculated cross sections has been studied. A medium modification of the 'elementary' NN interaction is also considered. The neutron differential cross sections have been calculated using the phenomenological and the recently proposed semiphenomenological neutron and proton target densities so as to check the validity of the semiphenomenological density model. We found that our method of analysis gives a very good description of the experimental data.

Alvi, M. A.; Arafah, M. R.; Madani, J. H.; Ahmad, I. [Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah-21589 (Saudi Arabia)

2009-02-15

338

Energy band-gap shift with elastic strain in GaxIn1 - xP epitaxial layers on (001) GaAs substrates  

Microsoft Academic Search

It is demonstrated that the energy band gap in epitaxial layers is changed by biaxial elastic strains which are produced by lattice mismatches in heterostructures. The epitaxial layers used in this work were Gax In1?xP layers grown on (001) GaAs substrates by liquid phase epitaxy. The energy band-gap shifts were determined by comparing the photoluminescence peak energies of the as-grown

Hiromitsu Asai; Kunishige Oe

1983-01-01

339

A model analytic potential energy function for formyl radical decomposition  

SciTech Connect

An analytic function for the ground-electronic-state HCO {yields} H + CO potential energy surface is presented. Both experimental and ab initio data are used to derive parameters for the potential energy surface. Bound-state eigenvalues are obtained, and the results show good agreement with reported experimental and theoretical values. The analytic function is quite flexible and can be easily adjusted to determine how specific potential energy surface properties affect state-specific unimolecular decomposition.

Cho, Seonwoog; Hase, W.L. (Wayne State Univ., Detroit, MI (USA)); Swamy, K.N. (IBM Corp., Kingston, NY (USA))

1990-09-20

340

Potent melanin production enhancement of human tyrosinase gene by Tat and an entrapment in elastic cationic niosomes: potential application in vitiligo gene therapy.  

PubMed

Potent melanin production enhancement of human tyrosinase plasmid (pAH7/Tyr, P) in mouse melanoma cells (B(16)F(10)) by Tat peptide (T) and an entrapment in elastic cationic niosomes (E) was described. The E composed of Tween 61/cholesterol/dodecyl dimethyl ammonium bromide at 1:1:0.5 molar ratio was prepared by freeze-dried emptying liposomes method. PE at P/E ratio of 1:160 w/w and TPE at T/P/E ratio of 0.125:1:160, 0.25:1:160, and 0.5:1:160 w/w/w were prepared. The final concentration of the plasmid in the study was 4 ng/?L. By sulforhodamine B assay, PE and TPE complexes showed slight or no cytotoxic effect. The cells transfected with TPE (0.5:1:160) exhibited the highest enhancement of tyrosinase enzyme activity of 11.82-, 7.67-, 5.07-, and 6.29-folds of control, P, PE, and TP (0.5:1) and melanin production of 13.03-, 8.46-, 5.36-, and 6.58-folds of control, P, PE, and TP (0.5:1), respectively. The elastic cationic niosomes demonstrated an increase in thermal stability of P at 4 ± 2, 25 ± 2, and 45 ± 2 °C. The vesicular size and the zeta potential values of PE and TPE complexes were slightly increased but still in the range of stable dispersion (out of ±30 mV). These results indicated the high potential application of the TPE complexes for further investigation for vitiligo gene therapy. PMID:22958397

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

2012-10-09

341

Electrical energy and cost savings potential at DOD facilities  

Microsoft Academic Search

The US Department of Defense (DOD) has been mandated to reduce energy consumption and costs by 20% from 1985 to 2000 and by 30% from 1985 to 2005. Reduction of electrical energy consumption at DOD facilities requires a better understanding of energy consumption patterns and energy and financial savings potential. This paper utilizes two independent studies--EDA (End-Use Disaggregation Algorithm) and

S. Konopacki; H. Akbari; L. Lister; L. DeBaille

1996-01-01

342

Stretching the inflaton potential with kinetic energy  

Microsoft Academic Search

Inflation near a maximum of the potential is studied when nonlocal derivative operators are included in the inflaton Lagrangian. Such terms can impose additional sources of friction on the field. For an arbitrary spacetime geometry, these effects can be quantified in terms of a local field theory with a potential whose curvature around the turning point is strongly suppressed. This

James E. Lidsey

2007-01-01

343

Stiffness adjustment of a series elastic actuator in a knee prosthesis for walking and running: The trade-off between energy and peak power optimization  

Microsoft Academic Search

In ankle-foot prostheses a serial spring can assist the motor to reduce peak power (PP) and energy requirements (ER) during locomotion. Similar benefits can be expected for an active knee prosthesis. We compare the situation of a direct drive with a series elastic actuator optimized for minimal ER or for minimal PP. The simulations indicate that at the knee joint

Martin Grimmer; Andre Seyfarth

2011-01-01

344

Scattering of electrons by atomic hydrogen at intermediate energies: Elastic scattering and n = 2 excitation from 12 to 54 eV  

SciTech Connect

Cross sections for elastic scattering and excitation of the n = 2 states of atomic hydrogen by electrons are computed for incident energies in the range from 12 to 54 eV. The calculations are based primarily on an 11-state expansion including seven pseudostates. Pseudothresholds and pseudoresonances are suppressed by appropriate averaging.

Callaway, J.

1985-08-01

345

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

NASA Astrophysics Data System (ADS)

We report absolute differential cross sections (DCSs) for elastic electron scattering from GeF4. 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 GeF4 elastic DCSs to similar data for scattering from CF4 and SiF4. All these three species possess Td 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 GeF4 elastic integral cross sections are derived and compared to our IAM-SCAR computations and with independent total cross section values.

Kato, H.; Suga, A.; Hoshino, M.; Blanco, F.; García, G.; Lima~o-Vieira, P.; Brunger, M. J.; Tanaka, H.

2012-04-01

346

Renewable Energy Resources Potential in Lao PDR  

Microsoft Academic Search

Renewable energy resources provide a large share of the total energy consumption of many developing countries. Evaluation of these resources has not been made in many countries and in many cases, data necessary to estimate the resource availability is also not easily available. However, for the profitable and sustained exploitation of these resources, a knowledge of their availability should be

KAYASITH SADETTANH

2004-01-01

347

HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS  

SciTech Connect

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.

PARSA,Z.

2000-04-07

348

Energy in America: Progress and Potential.  

ERIC Educational Resources Information Center

|An overview of America's energy situation is presented with emphasis on recent progress, the risk of depending upon foreign oil, and policy choices. Section one reviews the energy problems of the 1970s, issues of the 1980s, concerns for the future, and choices that if made today could alleviate future problems. Section two examines past problems,…

American Petroleum Inst., Washington, DC.

349

Energy conservation potential of surface modification technologies  

SciTech Connect

This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

Le, H.K.; Horne, D.M.; Silberglitt, R.S.

1985-09-01

350

Expedient Wind Energy Potential in Louisiana  

Microsoft Academic Search

Year after year, the world improves upon new ideas and forms of practical ways of applying green energy to humanity''s daily life. Some of these types include solar, nuclear, and natural gas energy, but wind power is growing in the ranks as far as popularity and usage. Countries such as China, the United States, and Germany have led the interest

Jasmin Honegger; Yucheng Liu

2012-01-01

351

Stretching the inflaton potential with kinetic energy  

Microsoft Academic Search

Inflation near a maximum of the potential is studied when non-local\\u000aderivative operators are included in the inflaton Lagrangian. Such terms can\\u000aimpose additional sources of friction on the field. For an arbitrary spacetime\\u000ageometry, these effects can be quantified in terms of a local field theory with\\u000aa potential whose curvature around the turning point is strongly suppressed.\\u000aThis

James E. Lidsey

2007-01-01

352

Misconceptions about the energy of waves in a strained string  

NASA Astrophysics Data System (ADS)

The localization of the elastic potential energy associated with transverse and longitudinal waves in a stretched string is discussed. Some misunderstandings about different expressions for the density of potential energy encountered in the literature are clarified. The widespread opinion regarding the inherent ambiguity of the density of elastic potential energy is criticized.

Butikov, Eugene I.

2012-09-01

353

Theory of orientational elasticity  

Microsoft Academic Search

In order to describe the local orientation of a macroscopic medium with broken rotational symmetries, an orientational field that consists of three orthonormal vectors is introduced. Next, the deformation free-energy density is constructed and a detailed acount is given of the form and number of the appearing surface terms. It appears that the general expression involves 39 bulk elastic constants

S. Stallinga; G. Vertogen

1994-01-01

354

Soft diffraction and the elastic slope at Tevatron and LHC energies: a multi-Pomeron approach  

Microsoft Academic Search

.   We present a formalism for high energy soft processes, mediated by Pomerons, which embodies pion-loop insertions in the Pomeron\\u000a trajectory, rescattering effects via a two-channel eikonal and high-mass diffractive dissociation. It describes all the main\\u000a features of the data throughout the ISR to Tevatron energy interval. We give predictions for soft diffractive phenomena at\\u000a the LHC energy, and we

V. A. Khoze; A. D. Martin; M. G. Ryskina

2000-01-01

355

Predictions for elastic and inelastic nucleon-nucleus cross sections at high energies  

Microsoft Academic Search

The effect of intermediate resonance production on particle-nucleus cross sections is discussed for particle energies in the energy range up to 1 TeV. It is shown that from present cosmic ray data in pp inelastic cross sections, a decrease in the total and inelastic cross sections for p-nucleus scattering of less than 10% can be expected in this energy range

J. S. Trefil

1971-01-01

356

?? bond energy from the Nijmegen potentials  

NASA Astrophysics Data System (ADS)

The ?? bond energy ? B?? in ?? hypernuclei is obtained from a G -matrix calculation which includes the coupling between the ?? , ?N , and ?? channels, as well as the effect of Pauli blocking to all orders. The Nijmegen NSC97e model is used as bare baryon-baryon interaction in the strangeness S=-2 sector. The ?? - ?N coupling increases substantially the bond energy with respect to the uncoupled ?? case. However, the additional incorporation of the ?? channel, which couples simultaneously to ?? and ?N states, has a surprisingly drastic effect and reduces the bond energy down to a value closer to that obtained in an uncoupled calculation. We find that a complete treatment of Pauli blocking reduces the repulsive effect on the bond energy to about half of what was claimed before.

Vidaña, I.; Ramos, A.; Polls, A.

2004-08-01

357

High-energy transmission Laue micro-beam X-ray diffraction: a probe for intra-granular lattice orientation and elastic strain in thicker samples.  

PubMed

An understanding of the mechanical response of modern engineering alloys to complex loading conditions is essential for the design of load-bearing components in high-performance safety-critical aerospace applications. A detailed knowledge of how material behaviour is modified by fatigue and the ability to predict failure reliably are vital for enhanced component performance. Unlike macroscopic bulk properties (e.g. stiffness, yield stress, etc.) that depend on the average behaviour of many grains, material failure is governed by `weakest link'-type mechanisms. It is strongly dependent on the anisotropic single-crystal elastic-plastic behaviour, local morphology and microstructure, and grain-to-grain interactions. For the development and validation of models that capture these complex phenomena, the ability to probe deformation behaviour at the micro-scale is key. The diffraction of highly penetrating synchrotron X-rays is well suited to this purpose and micro-beam Laue diffraction is a particularly powerful tool that has emerged in recent years. Typically it uses photon energies of 5-25?keV, limiting penetration into the material, so that only thin samples or near-surface regions can be studied. In this paper the development of high-energy transmission Laue (HETL) micro-beam X-ray diffraction is described, extending the micro-beam Laue technique to significantly higher photon energies (50-150?keV). It allows the probing of thicker sample sections, with the potential for grain-level characterization of real engineering components. The new HETL technique is used to study the deformation behaviour of individual grains in a large-grained polycrystalline nickel sample during in situ tensile loading. Refinement of the Laue diffraction patterns yields lattice orientations and qualitative information about elastic strains. After deformation, bands of high lattice misorientation can be identified in the sample. Orientation spread within individual scattering volumes is studied using a pattern-matching approach. The results highlight the inability of a simple Schmid-factor model to capture the behaviour of individual grains and illustrate the need for complementary mechanical modelling. PMID:22514163

Hofmann, Felix; Song, Xu; Abbey, Brian; Jun, Tea-Sung; Korsunsky, Alexander M

2012-03-16

358

An Analysis of the Wind Energy Potential of Elazig, Turkey  

Microsoft Academic Search

In this study, the wind energy potential of Elazig is statistically analyzed based on hourly measured wind speed data over the five-year period from 1998 to 2002. The probability density distributions are derived from cumulative distribution functions. Two probability density functions are fitted to the measured probability distribution on a yearly basis. The wind energy potential of the location is

E. Kavak Akpinar; S. Akpinar

2004-01-01

359

Appearance Potential Studies. I. Determination of Excess Kinetic Energy  

Microsoft Academic Search

The metastable ion suppressor on the Consolidated Engineering Corporation Model 21—103 mass spectrometer has been used as a retarding potential device to determine the excess kinetic energies possessed by the ions formed during appearance potential measurements. The suppressor setting at which an ion beam is extinguished is compared with the extinction setting for an ion beam with no excess energy.

Richard J. Kandel

1954-01-01

360

The elastic fibre network of the human lumbar anulus fibrosus: architecture, mechanical function and potential role in the progression of intervertebral disc degeneration  

Microsoft Academic Search

Elastic fibres are critical constituents of dynamic biological structures that functionally require elasticity and resilience.\\u000a The network of elastic fibres in the anulus fibrosus of the intervertebral disc is extensive, however until recently, the\\u000a majority of histological, biochemical and biomechanical studies have focussed on the roles of other extracellular matrix constituents\\u000a such as collagens and proteoglycans. The resulting lack of

Lachlan J. Smith; Nicola L. Fazzalari

2009-01-01

361

Elastic AES  

Microsoft Academic Search

Recently an algorithmic schema was proposed for converting any ex- isting block cipher into one which excepts variable length inputs with the compu- tational workload increasing in proportion to the block size. The resulting cipher is referred to as an elastic block cipher. The initial work presented immunity to certain key recovery attacks, and left open further analysis of the

Debra L. Cook; Moti Yung; Angelos D. Keromytis

362

ECONOMIC DEVELOPMENT POTENTIAL OF CONVENTIONAL AND POTENTIAL ALTERNATIVE ENERGY SOURCES IN APPALACHIAN COUNTIES  

Microsoft Academic Search

Appalachia has significant potential to contribute to both national energy independence and to achieve regional import substitution in the energy sector. There are significant opportunities for regional and community- scaled industrial development, especially in the areas of bio-fuels. Major choices exist in the selection of a minimum scale of production for many of the new technologies and energy sources. Technologies

Amy Glasmeier; Tom Bell

363

Off-shell effects in elastic pion-nucleus scattering  

Microsoft Academic Search

For elastic scattering of pions from nuclei in the energy region of the (3, 3) resonance, the effects of the binding of the target nucleons are shown to be important in the calculation of the pion-nucleus optical potential. The size of these binding effects is estimated for the case in which the free pion-nucleon scattering amplitude is represented by a

D. J. Ernst; C. M. Shakin; R. M. Thaler

1974-01-01

364

Energy distribution between seismic waves of different types produced in an elastic half-space by a source with an arbitrary radiation pattern  

Microsoft Academic Search

The energy distribution between different types of seismic waves produced by a source of longitudinal and transverse waves\\u000a with an arbitrary radiation pattern in an elastic half-space is considered. With an appropriate choice of the angular distribution\\u000a functions, this source can model an earthquake source. A direct theoretical comparison of the energy distributions of seismic\\u000a waves generated by an underground

G. A. Maximov; M. E. Merkulov; V. Yu. Kudryavtsev

2003-01-01

365

RELEASE OF ELASTIC STRAIN ENERGY AS ACOUSTIC EMISSION DURING THE REVERSE THERMOELASTIC PHASE TRANSFORMATION IN Au-47.5 at.percent Cd ALLOY  

SciTech Connect

The objective of this paper is to present experimental evidence concerning the acoustic energy evolved during the heating and cooling phase changes in Au-47.5 at.% Cd polycrystals. The results are examined from the point of view of the stored elastic strain energy during the martensite formation, and the frictional work that is dissipated by the movement of martensite interfaces in either direction, upon heating and cooling.

Baram, J.; Avissar, J.; Gefen, Y.; Rosen, M.

1980-05-01

366

Preliminary evaluation of wind energy potential: Cook Inlet area, Alaska  

SciTech Connect

This report summarizes work on a project performed under contract to the Alaska Power Administration (APA). The objective of this research was to make a preliminary assessment of the wind energy potential for interconnection with the Cook Inlet area electric power transmission and distribution systems, to identify the most likely candidate regions (25 to 100 square miles each) for energy potential, and to recommend a monitoring program sufficient to quantify the potential.

Hiester, T.R.

1980-06-01

367

Potential energy studies on silane dimers  

Microsoft Academic Search

Intermolecular interactions and parameters for use in MD studies of large molecule systems have earlier been determined for hydrocarbons, carbon tetrahalides and sulfur. The paper reports a model representing nonbonding interactions between silane molecules, which were examined in the same way as hydrocarbons in an earlier (neopentane, isopropane, propane, and ethane) study. Intermolecular potentials were determined for 11 combinations of

Riina Mahlanen; Tapani A. Pakkanen

2011-01-01

368

Potential Energy Sources Pose Mining Problem  

ERIC Educational Resources Information Center

Summarizes the discussions of a Division of Industrial and Engineering Chemistry symposium on solids handling for synthetic fuels production. Included is a description of technical difficulties with the use of coal seams and deposits of oil shale and oil sand as potential sources of fuel. (CC)

Chemical and Engineering News, 1974

1974-01-01

369

Potential Energy Sources Pose Mining Problem  

ERIC Educational Resources Information Center

|Summarizes the discussions of a Division of Industrial and Engineering Chemistry symposium on solids handling for synthetic fuels production. Included is a description of technical difficulties with the use of coal seams and deposits of oil shale and oil sand as potential sources of fuel. (CC)|

Chemical and Engineering News, 1974

1974-01-01

370

Potential energy landscape contribution to the dynamic heat capacity  

NASA Astrophysics Data System (ADS)

The dynamic heat capacity of a simple polymeric, model glass former was computed using molecular dynamics simulations by sinusoidally driving the temperature and recording the resultant energy. The underlying potential energy landscape of the system was probed by taking a time series of particle positions and quenching them. The resulting dynamic heat capacity demonstrates that the long time relaxation is the direct result of dynamics resulting from the potential energy landscape.

McCoy, John; Brown, Jonathan

2013-03-01

371

Solar Energy: Potential Powerhouse for Jobs  

ERIC Educational Resources Information Center

Components of solar energy systems are described, the development of the solar industry discussed, and implications are drawn for employment opportunities in industries (which may expand into new, solar-related areas) and in the professions, from law to sales, upon the advent of solar heating. (AJ)

McCallion, Tom

1976-01-01

372

Biomass energy in China and its potential  

Microsoft Academic Search

Biomass is a significant source of energy in China today, particularly in rural areas. However, most current use of firewood and agricultural residues for cooking and heating brings with it detrimental effects of indoor air pollution and associated adverse health impacts. In addition, the time spent collecting biomass fuels creates a burden on women and children, which reduces their time

Li Jingjing; Zhuang Xing; Pat DeLaquil; Eric D. Larson

2001-01-01

373

Integral Representation Results for Energies Defined on Stochastic Lattices and Application to Nonlinear Elasticity  

NASA Astrophysics Data System (ADS)

This article is devoted to the study of the asymptotic behavior of a class of energies defined on stochastic lattices. Under polynomial growth assumptions, we prove that the energy functionals {F_\\varepsilon} stored in the deformation of an {{\\varepsilon}}-scaling of a stochastic lattice ?-converge to a continuous energy functional when {{\\varepsilon}} goes to zero. In particular, the limiting energy functional is of integral type, and deterministic if the lattice is ergodic. We also generalize, to systems and nonlinear settings, well-known results on stochastic homogenization of discrete elliptic equations. As an application of the main result, we prove the convergence of a discrete model for rubber towards the nonlinear theory of continuum mechanics. We finally address some mechanical properties of the limiting models, such as frame-invariance, isotropy and natural states.

Alicandro, Roberto; Cicalese, Marco; Gloria, Antoine

2011-06-01

374

ENERGY CROP POTENTIALS FOR BIOENERGY IN EU27  

Microsoft Academic Search

Bioenergy gives Europe the best opportunity to reduce GHG emission and secure its energy supply. However, the biomass production should not create additional pressure on the environment. Therefore, for presented calculations, biomass for energy utilization originates from the cropland of the agricultural areas. Permanent grassland, areas of agro-forestry and pasture have not been taken into account. The energy crops potential

Jens Bo; Holm Nielsen; Piotr Oleskowicz-Popiel; Teodorita Al Seadi

375

Determination of wind energy potential in Kirklareli-Turkey  

Microsoft Academic Search

Wind energy has become an important source that has begun to be used for energy in all over the world in recent years. In this study, by examining the wind potential of the western region of Turkey in detail, an analysis was made. The data were provided by the State Meteorology Affairs Kirklareli Office. In Kirklareli region, the energy produced

Sedat Ersoz; Tahir Cetin Akinci; H. Selcuk Nogay; Gokhan Dogan

2012-01-01

376

Limit Cycle Oscillations of a Nonlinear Piezo-magneto-elastic Structure for Broadband Vibration Energy Harvesting  

Microsoft Academic Search

\\u000a Vibration-based energy harvesting has been investigated by several researchers over the last decade. Typically, devices employing\\u000a piezoelectric, electromagnetic, electrostatic and magnetostrictive transductions have been designed in order to convert ambient\\u000a vibrations into electricity under resonance excitation. Regardless of the transduction mechanism, a primary issue in resonant\\u000a energy harvesters is that the best performance of the device is limited to resonance

A. Erturk; J. Hoffmann; D. J. Inman

377

Elastic scattering threshold anomaly and near-barrier heavy-ion fusion  

NASA Astrophysics Data System (ADS)

From an analysis of heavy-ion elastic scattering and fusion data available for three systems, Udagawa et al. presented evidence that the ``threshold barrier'' (T) determined from fusion is approximately equal to the ``threshold energy'' (Ea) extracted from the imaginary part of optical potential for elastic scattering in the vicinity of the Coulomb barrier. We have extended this investigation to include seven more systems for which the relevant data are available. Furthermore, from a comparison of sets of ?V, the polarization potential (deduced from elastic scattering), and B-T, the barrier difference (deduced from fusion) values, it is suggested that the two quantities are correlated.

Kailas, S.; Singh, P.

1994-08-01

378

ENERGY CONSERVATION POTENTIAL OF URBAN TREE PLANTING  

Microsoft Academic Search

Findings from monitoring and computer simu- lation studies indicate that trees can be a cost-effective energy conservation measure for some electric utilities. Our simula- tions suggest that a single 25-ft tall tree can reduce annual heating and cooling costs of a typical residence by 8 to 12 percent ($10-25). Assuming annual savings of $10 per household, a nationwide residential tree

E. Gregory McPherson; Rowan A. Rowntree

1993-01-01

379

Large-angle quasi-elastic scattering around the Coulomb barrier  

SciTech Connect

We summarize recent theoretical activities on heavy-ion quasi-elastic scattering at energies around the Coulomb barrier. We first introduce a barrier distribution defined in terms of cross sections of large-angle quasi-elastic scattering. We discuss possible advantages for its exploitation, putting a particular emphasis on future experiments with radioactive beams. We then present our recent systematic studies on quasi-elastic scattering at deep-subbarrier energies, that offer an unambiguous way to extract the surface diffuseness parameter of the nucleus-nucleus potential.

Hagino, K. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

2006-11-02

380

Realizing the potential of nuclear energy. [Monograph  

SciTech Connect

The future of nuclear power, just as the future of America, can be viewed with optimism. There is hope in America's record of overcoming obstacles, but growth is essential for that hope to be realized. Despite the downturn in energy demand made possible by conservation, we will need a 35% growth in total energy for new workers and production. Electricity generated by nuclear or coal can make US production more cost-competitive, and it can power mass-transit systems, electric heat pumps, and communications and information systems. Changes in electricity and gross national product (GNP) have been more closely in step since 1973 than have total energy and GNP. The nuclear power units now under construction will add 80,000 megawatts to the 56,000 now on line. It is important to note that, while utilities are cancelling plans for nuclear plants, they aren't ordering new coal plants, which shows the impact of the high cost of money. Interest rates must come down and public-relations efforts to sell electricity must improve to change the situation. Although capital shortages are real, waste disposal is a problem of perception that was politically induced because the government failed to provide a demonstration of safety as the French are doing. Streamlined regulatory and insurance procedures can help to justify optimism in the nuclear option. 4 figures. (DCK)

Walske, C.

1982-01-01

381

Energy savings potential from energy-conserving irrigation systems  

SciTech Connect

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.

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

1982-11-01

382

Potential problems and limitations of energy conservation and energy efficiency  

Microsoft Academic Search

We discuss that whilst energy conservation and energy efficiency both ultimately have the same goal they attempt to achieve this via very different approaches. We then discuss how both options face significant barriers to ultimately successfully reduce electricity consumption.

Matt Croucher

2011-01-01

383

Energy Storage:Maximising Irelands Wind Energy Potential  

Microsoft Academic Search

Ireland plan's to generate up to 40% of its electricity from wind generation by 2020. This thesis outlines the problems that may be faced by the electricity system and illustrates the benefits that large scale energy storage can bring to the electricity system when trying to integrate large amounts of wind energy. Energy storage is currently a topical subject in

Damien Kelly

2010-01-01

384

A boost to low energy nuclear reactions from preliminary elastic collisions (Carambole collisions)  

Microsoft Academic Search

In conventional nuclear experiments a beam of accelerated nuclei collides with a target nucleus that is surrounded by other nuclei in a molecule, in condensed matter, or in a plasma environment. It is shown that for low collision energies possible nuclear reactions (including deuterium fusion) are strongly boosted by the environment. The effect originates from a chain of preliminary three

M. Yu. Kuchiev; B. L. Altshuler; V. V. Flambaum

2000-01-01

385

Modelling of uncertainties and price elastic demands in energy-environment planning for India  

Microsoft Academic Search

This paper describes two variants of the Indian MARKAL model: a long-term technology oriented optimisation model for energy-environment planning for India. The first variant uses stochastic programming to include future uncertainties in the analysis. Details of model formulation, results and sensitivity analysis are described here. The second variant uses an innovative approach to simulate price sensitive demands within a linear

Amit Kanudia; PR Shukla

1998-01-01

386

Relationships between available potential energy, kinetic energy, and extratropical cyclone activity within east coast cyclogenetic regions  

Microsoft Academic Search

Interrelationships between the available potential energy and kinetic energy associated with extratropical cyclones are examined for portions of the First GARP Global Experiment (FGGE) year. The study is confirmed to the cyclogenetically active regions encompassing the eastern coasts of Asia and North America. Calculations of vertically integrated available potential energy (APE) and kinetic energy (KE) are done for an active

John V. Zapotocny

1987-01-01

387

Nanoplate elasticity under surface reconstruction  

NASA Astrophysics Data System (ADS)

Using classical molecular statics simulations, we show that nanoplate elasticity strongly depends on surface reconstruction and alignment of bond chains. Because of its well-established surface reconstructions and the readily available interatomic potential, diamond-cubic silicon is the prototype of this study. We focus on silicon nanoplates of high-symmetry surfaces, {111} and {100}; with 7×7 and 2×1 reconstructions. Nanoplates with unreconstructed {111} surfaces are elastically stiffer than bulk. In contrast, the same nanoplates with 7×7 reconstructed {111} surfaces are elastically softer than bulk. On {100} surfaces, the 2×1 surface reconstruction has little impact. The bond chains are along one of the two <110> directions, making the two <110> directions nonequivalent. The alignment of the bond chains on the opposite surfaces of a nanoplate dictates its elastic anisotropy. The sensitivity of nanoplate elasticity on details of surface atomic arrangements may impact the application of nanoplates (or nanocantilevers) as sensors.

Shim, Hyun Woo; Zhou, L. G.; Huang, Hanchen; Cale, Timothy S.

2005-04-01

388

Global permutationally invariant potential energy surface for ozone forming reaction  

NASA Astrophysics Data System (ADS)

We constructed new global potential energy surface for O + O2 --> O3 reaction. It is based on high level electronic structure theory calculations and employs fitting by permutationally invariant polynomial functions. This method of surface construction takes full advantage of permutation symmetry of three O nuclei and allows reducing dramatically the number of ab initio data points needed for accurate surface representation. New potential energy surface offers dramatic improvement over older surface of ozone in terms of dissociation energy and behavior along the minimum energy path. It can be used to refine the existing theories of ozone formation.

Ayouz, Mehdi; Babikov, Dmitri

2013-04-01

389

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

PubMed

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

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

2008-03-01

390

Waves and energy in random elastic guided media through the stochastic wave finite element method  

NASA Astrophysics Data System (ADS)

Energy propagation in random viscoelastic media is considered in this Letter. The forced response of uncertain waveguide subject to time harmonic loading is treated. This energy model is based on a spectral approach called the "Stochastic Wave Finite Element" (SWFE) method which is detailed in this Letter. Assuming that the random properties are spatially homogeneous in the media, the SWFE is a hybridization of the deterministic wave finite element and a parametric probabilistic approach. The proposed model is applicable in a wide frequency band with reduced time consumption. Numerical examples show the effectiveness of the proposed approach to predict the statistics of kinematic and quadratic variables of guided wave propagation. The results are compared to Monte Carlo simulations.

Ben Souf, M. A.; Bareille, O.; Ichchou, M. N.; Bouchoucha, F.; Haddar, M.

2013-11-01

391

A boost to low energy nuclear reactions from preliminary elastic collisions (Carambole collisions)  

Microsoft Academic Search

In conventional nuclear experiments a beam of accelerated nuclei collides\\u000awith a target nucleus that is surrounded by other nuclei in a molecule, in\\u000acondensed matter, or in a plasma environment. It is shown that for low\\u000acollision energies possible nuclear reactions (including deuterium fusion) are\\u000astrongly boosted by the environment. The effect originates from a chain of\\u000apreliminary three

M. Yu. Kuchiev; B. L. Altshuler; V. V. Flambaum

2000-01-01

392

Exact Energy and Momentum Conserving Algorithms for General Models in Nonlinear Elasticity  

Microsoft Academic Search

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

O. Gonzalez

1999-01-01

393

Exact energy and momentum conserving algorithms for general models in nonlinear elasticity  

Microsoft Academic Search

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

O. Gonzalez

2000-01-01

394

Rab1a and Rab5a preferentially bind to binary lipid compositions with higher stored curvature elastic energy.  

PubMed

Rab proteins are a large family of GTP-binding proteins that regulate cellular membrane traffic and organelle identity. Rab proteins cycle between association with membranes and binding to RabGDI. Bound on membranes, each Rab has a very specific cellular location and it is this remarkable degree of specificity with which Rab GTPases recognize distinct subsets of intracellular membranes that forms the basis of their ability to act as key cellular regulators, determining the recruitment of downstream effectors to the correct membrane at the correct time. The molecular mechanisms controlling Rab localization remain poorly understood. Here, we present a fluorescence-based assay to investigate Rab GTPase membrane extraction and delivery by RabGDI. Using EGFP-Rab fusion proteins the amount of Rab:GDI complex obtained by GDI extraction of Rab proteins from HEK293 membranes could be determined, enabling control of complex concentration. Subsequent partitioning of the Rab GTPases into vesicles made up of artificial binary lipid mixtures showed for the first time, that the composition of the target membrane plays a key role in the localization of Rab proteins by sensing the stored curvature elastic energy in the membrane. PMID:23815289

Kirsten, Marie L; Baron, Rudi A; Seabra, Miguel C; Ces, Oscar

2013-07-01

395

Comparison of elastic scattering spectroscopy with histology in ex vivo prostate glands: potential application for optically guided biopsy and directed treatment.  

PubMed

The false-negative rate of ultrasound-guided sextant prostate biopsy has been estimated to be as high as 35 %. A significant percentage (10-35 %) of these prostate cancers diagnosed at a second or later attempt are high grade and, therefore, potentially lethal. We discuss the feasibility for performing optically guided biopsy using elastic scattering spectroscopy (ESS) to reduce sampling errors and improve sensitivity. ESS measurements were performed on 42 prostate glands ex vivo and correlated with standard histopathological assessment. Sliced glands were examined with wavelength ranges of 330-760 nm. The ESS portable system used a new fiber-optic probe with integrated cutting tool, designed specifically for ex vivo pathology applications. ESS spectra were grouped by diagnosis from standard histopathological procedure and then classified using linear support vector machine. Preliminary data are encouraging. ESS data showed strong spectral trends correlating with the histopathological assignments. The classification results showed a sensitivity of 0.83 and specificity of 0.87 for distinguishing dysplastic prostatic tissue from benign prostatic tissue. Similar results were obtained for distinguishing dysplastic prostatic tissue from prostatitis with a sensitivity and specificity of 0.80 and 0.88, respectively. The negative predictive values obtained with ESS are better than those obtained with transrectal ultrasound (TRUS)-guided core-needle biopsy. PMID:23247663

A'amar, O M; Liou, L; Rodriguez-Diaz, E; De Las Morenas, A; Bigio, I J

2012-12-18

396

Estimating the Energy-Efficiency Potential in the Eastern Interconnection.  

National Technical Information Service (NTIS)

Comprehensive and integrated resource planning considers the potential for increases in energy efficiency to reduce the requirements for new generation and transmission investments. This study supports such planning efforts by developing robust estimates ...

M. A. Brown Y. Wang

2013-01-01

397

Potential Effects of Geothermal Energy Conversion on Imperial Valley Ecosystems.  

National Technical Information Service (NTIS)

This workshop on potential effects of geothermal energy conversion on the ecology of Imperial Valley brought together personnel of Lawrence Livermore Laboratory and many collaborators under the sponsorship of the ERDA Imperial Valley Environmental Project...

J. H. Shinn

1976-01-01

398

Potential energy stored by planets and grand minima events  

NASA Astrophysics Data System (ADS)

Recently, Wolff & Patrone (2010), have developed a simple but very interesting model by which the movement of the Sun around the barycentre of the Solar system could create potential energy that could be released by flows pre-existing inside the Sun. The authors claim that it is the first mechanism showing how planetary movements can modify internal structure in the Sun that can be related to solar cycle. In this work we point out limitations of mentioned mechanism (which is based on interchange arguments), which could be inapplicable to a real star. Then, we calculate the temporal evolution of potential energy stored in zones of Sun's interior in which the potential energy could be most efficiently stored taking into account detailed barycentric Sun dynamics. We show strong variations of potential energy related to Maunder Minimum, Dalton Minimum and the maximum of Cycle 22, around 1990. We discuss briefly possible implications of this putative mechanism to solar cycle specially Grand Minima events.

Cionco, Rodolfo G.

2012-07-01

399

Potential Use of Ionising Energy Treatment in Queensland's Horticultural Industries.  

National Technical Information Service (NTIS)

The potential application of ionising energy treatment technology in Queensland falls into three categories: insect disinfestation, disease control and quality improvement. The technology fulfils the requirements of a disinfestation treatment against Quee...

N. W. Heather P. T. Sheehy I. F. Muirhead B. I. Brown R. N. Hassall

1985-01-01

400

Potential Impacts of Nanotechnology on Energy Transmission Applications and Needs.  

National Technical Information Service (NTIS)

The application of nanotechnologies to energy transmission has the potential to significantly impact both the deployed transmission technologies and the need for additional development. This could be a factor in assessing environmental impacts of right-of...

D. Elcock

2007-01-01

401

Theoretical Characterization of the Potential Energy Surface for NH + NO.  

National Technical Information Service (NTIS)

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 configu...

S. P. Walch

1992-01-01

402

Global Potential Energy Surface for ArH2.  

National Technical Information Service (NTIS)

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 ...

D. W. Schwenke S. P. Walch P. R. Taylor

1992-01-01

403

Mass Energy Equivalence Formula Must Include Rotational and Vibrational Kinetuic Energies as Well As Potential Energies  

NASA Astrophysics Data System (ADS)

Originally Einstein proposed the the mass-energy equivalence at low speeds as E=mc^2 + 1/2 mv^2. However, a mass may also be rotating and vibrating as well as moving linearly. Although small, these kinetic energies must be included in formulating a true mathematical statement of the mass-energy equivalence. Also, gravitational, electromagneic and magnetic potential energies must be included in the mass-energy equivalence mathematical statement. While the kinetic energy factors may differ in each physical situation such as types of vibrations and rotations, the basic equation for the mass- energy equivalence is therefore E = m0c^2 + 1/2m0v^2 + 1/2I2?+ 1/2kx^2 + WG+ WE+ WM.

Brekke, Stewart

2010-11-01

404

Dynamics and Potential Energy Landscape of Supercooled Water  

Microsoft Academic Search

We present molecular dynamics simulations of the SPC\\/E model of water to explore the connection between dynamic properties and the potential energy landscape. We calculate the configurational entropy and instantaneous normal mode (or local potential energy curvature) spectrum in the same region of the phase diagram where the dynamics are well-described by the predictions of the mode-coupling theory. We find

Francis W. Starr; Emilia Lanave; Antonio Scala; Francesco Sciortino; H. Eugene Stanley

2000-01-01

405

Fusion at deep subbarrier energies: potential inversion revisited  

SciTech Connect

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.

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

406

Approach for the three-body force effect in a high-energy approximation: Application to hadron-deuteron elastic scattering  

Microsoft Academic Search

In the framework of the Glauber approximation, using a simple suggested approach for the three-body force effect and taking into account D-state and phase variation effects, p-, p¯-, and pi--d elastic scattering differential cross sections at different energies are calculated. In general, one or two effects only from the three used effects are not enough to obtain a good fit

Mohamed A. Hassan; Tarek N. El-Din Salama; Zeinab S. Hassan

2001-01-01

407

Measurements of photon-atom elastic scattering cross-sections in the photon energy range 1 keV to 4 MeV  

Microsoft Academic Search

We review the current status of measurements of photon-atom elastic scattering cross-sections for the restricted photon energy range 1 keV up to 4 MeV. Among the key experimental factors which influence the accuracy and precision of a particular type of measurement are the choice of source, detector and scattering geometry. We have examined the interests which motivate the making of

D. A. Bradley; O. D. Goncalves; P. P. Kane

1999-01-01

408

Oxygen ordering and mobility in ReBa2Cu3O6+x by elastic energy loss and modulus measurements  

NASA Astrophysics Data System (ADS)

It is reported on new anelastic relaxation measurements in ReBa2Cu3O6+x for 0elastic energy dissipation observed above room temperature are interpreted in that framework. A new structural phase transition around 480 K is observed.

Canali, M.; Cannelli, G.; Cantelli, R.; Cordero, F.; Ferretti, M.; Trequattrini, F.

1991-12-01

409

Electron elastic back-scattering from aligned CO_2^+ molecular ions in the 15-30 eV energy range  

NASA Astrophysics Data System (ADS)

Angular distributions of electrons elastically back-scattered from aligned CO_2^+ ions are extracted in the 15-30 eV energy range from electron spectra recorded in field-free-aligned CO2 molecules using a femtosecond pump-probe scheme. The angular distributions are found to exhibit a steeper increase as the scattering angle goes from 150° to 180° for molecular ions aligned with the incident electron momentum.

Cornaggia, C.

2013-10-01

410

Correlation between shape resonance energies and C-C bond length in carbon-containing molecules: Elastic electron scattering and carbon K-shell excitation by photons.  

National Technical Information Service (NTIS)

We document the correlation of shape resonance energies resulting from (i) elastic electron scattering and (ii) carbon K-shell excitation with ic bond order (C-C bond length) for C(sub 2)H(sub 2), C(sub 2)H(sub 4), C(sub 2)H(sub 6), C(sub 3)H(sub 8), C(su...

M. Kimura

1994-01-01

411

Elastic and surface energies: Two key parameters for CdSe quantum dot formation  

SciTech Connect

The two-dimensional-three-dimensional transition of a strained CdSe layer on (001) ZnSe induced by the use of amorphous selenium is studied. To precisely control the thickness of the CdSe layer, atomic layer epitaxy growth mode is used. Atomic force microscopy and reflection high-energy electron diffraction measurements reveal the formation of CdSe islands when 3 ML (monolayers) of CdSe, corresponding to the critical thickness, are deposited. When only 2.5 ML of CdSe are deposited another relaxation mechanism is observed, leading to the appearance of strong undulations on the surface. For a 3 ML thick CdSe layer, transmission electron microscopy images indicate that the formation of the islands occurs only after the amorphous selenium desorption.

Robin, Ivan-Christophe; Andre, Regis; Bougerol, Catherine; Aichele, Thomas; Tatarenko, Serge [Laboratoire de Spectrometrie Physique/CNRS UMR5588, Universite Joseph Fourier, Grenoble, BP87, 38402 St. Martin d'Heres (France)

2006-06-05

412

Energy characteristics and savings potential in office buildings  

Microsoft Academic Search

The present paper reports the finding of a monitoring campaign in 186 office buildings in Greece. The specific energy consumption of the buildings for heating, cooling, and lighting purposes, as well as the consumption of the office equipment is reported. The impact of the used systems, techniques, and components is investigated. The potential and the limitations of various energy conservation

M. Santamouris; A. Argiriou; E. Dascalaki; C. Balaras; A. Gaglia

1994-01-01

413

Market Potential for Non-electric Applications of Nuclear Energy  

Microsoft Academic Search

The paper presents results of a recent IAEA study to assess the market potential for non-electric applications of nuclear energy in the near (before 2020) and long term (2020-2050). The applications covered are district heating, desalination, industrial heat supply, ship propulsion, energy supply for spacecraft, and, to a lesser extent, 'innovative' applications such as hydrogen production, coal gasification, etc. While

T. Konishi; S. Kononov; J. Kupitz; A. McDonald; H. H. Rogner; S. Nisan

2002-01-01

414

Overview of worldwide biomass energy potential and applications  

Microsoft Academic Search

As costs for traditional energy sources have risen around the world, more attention has been focused on biomass energy sources. These activities have occurred in both developed and undeveloped countries. This paper examines the need for alternate fuels on a worldwide basis, and discusses the potential for biomass fuel use in certain regions. In addition, the technologies for using biomass

J. L. Birchfield; W. S. Bulpitt

1982-01-01

415

Regional potentials for on-farm energy production alternatives  

Microsoft Academic Search

Alternative energy production options available to farmers in the United States are not equally adaptable throughout various regions. A literature review assesses indirect solar technologies for on-farm energy production and was the basis for selecting certain alternatives for further study. A regional assessment of the feasibility and potential profitability of on-farm alcohol production from grain, direct combustion, and gasification of

Dauve

1985-01-01

416

U. S. Building-Sector Energy Efficiency Potential.  

National Technical Information Service (NTIS)

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 p...

J. Koomey P. Biermayer R. Brown S. Borgeson

2008-01-01

417

The potential role of renewable energy in Moldova  

Microsoft Academic Search

The European Union (EU) is developing an increasingly close relationship with Moldova, going beyond cooperation, to gradual economic integration and a deepening of political cooperation. This fact indicates that eventually the adoption of EU legislation in the energy sector is a necessity. Therefore, the provision of a clear picture of the country’s renewable energy potential is considered essential, bearing in

Charikleia Karakosta; Stamatia Dimopoulou; Haris Doukas; John Psarras

2011-01-01

418

Brazilian waste potential: energy, environmental, social and economic benefits  

Microsoft Academic Search

The potential energy that could be produced from solid wastes in Brazil tops 50TWh. Equivalent to some 17% of the nation's total power consumption at costs that are competitive with more traditional options, this would also reduce greenhouse gases emissions. Moreover, managing wastes for energy generation purposes could well open up thousands of jobs for unskilled workers. Related to power

Luciano Basto Oliveira; Luiz Pinguelli Rosa

2003-01-01

419

On conversion between potential and kinetic energy in the atmosphere  

Microsoft Academic Search

Summary The mechanism of conversion between potential and kinetic energy in different parts of the Northern Hemisphere is discussed. In low latitudes, between the Equator and 30° N, a large part of the total energy conversion occurs in connection with a mean meridional circulation, the «Hadley circulation». In this the rate of conversion amounts to about 35×1010 kilojoules per second

E. Palmén

1961-01-01

420

Potential for Energy Conservation in the Cement Industry.  

National Technical Information Service (NTIS)

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 prim...

B. A. Garrett-Price

1985-01-01

421

U.S. Carbon offset potential using biomass energy systems  

Microsoft Academic Search

A previous analysis had assumed that about 20% of 1990 U.S. C emissions could be avoided by the substitution of biomass energy technologies for fossil energy technologies at some point in the future. Short-rotation woody crop (SRWC) plantations were found to be the dedicated feedstock supply system (DFSS) offering the greatest C emission reduction potential. High efficiency biomass to electricity

L. L. Wright; E. E. Hughes

1993-01-01

422

Distribution of Earthquake Input Energy in Structures.  

National Technical Information Service (NTIS)

In developing an energy-based design approach and assessing the damage potential of structures, one must know the distribution of earthquake input energy among energy components: kinetic, elastic strain, hysteretic, and damping. The report examines the in...

P. Khashaee B. Mohraz F. SAdek H. S. Lew J. L. Gross

2003-01-01

423

The Department of Defense energy vulnerabilities: Potential problems and observations  

NASA Astrophysics Data System (ADS)

The Department of Defense is almost entirely dependent on civilian energy supplies to meet its needs in both peacetime and periods of heightened conflict. There are a number of potential vulnerabilities to the continual and timely supply of energy to both the civilian and military sectors. These include denial of the energy resources themselves, disruption of critical transportation networks, destruction of storage facilities, and interruption of electrical power. This report briefly reviews the present situation for provision of energy from the civilian sector to the military. General vulnerabilities of the existing energy supply system are identified, along with the potential for armed aggression (including terrorist and sabotage activities) against the energy network. Conclusions and some tentative observations are made as to a proper response to the existing vulnerabilities.

Freiwald, D. A.; Berger, M. E.; Roach, J. F.

1982-08-01

424

Energy Consumption and Renewable Energy Development Potential on Indian Lands  

EIA Publications

Includes information on the electricity use and needs of Indian households and tribes, the comparative electricity rates that Indian households are paying, and the potential for renewable resources development of Indian lands.

Fred Mayes

2000-04-01

425

The effect of the new nucleon-nucleus elastic scattering data in LAHET{trademark} Version 2.8 on neutron displacement cross section calculations  

SciTech Connect

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.

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

426

Spontaneous dissipation of elastic energy by self-localizing thermal runaway  

NASA Astrophysics Data System (ADS)

Thermal runaway instability induced by material softening due to shear heating represents a potential mechanism for mechanical failure of viscoelastic solids. In this work we present a model based on a continuum formulation of a viscoelastic material with Arrhenius dependence of viscosity on temperature and investigate the behavior of the thermal runaway phenomenon by analytical and numerical methods. Approximate analytical descriptions of the problem reveal that onset of thermal runaway instability is controlled by only two dimensionless combinations of physical parameters. Numerical simulations of the model independently verify these analytical results and allow a quantitative examination of the complete time evolutions of the shear stress and the spatial distributions of temperature and displacement during runaway instability. Thus we find that thermal runaway processes may well develop under nonadiabatic conditions. Moreover, nonadiabaticity of the unstable runaway mode leads to continuous and extreme localization of the strain and temperature profiles in space, demonstrating that the thermal runaway process can cause shear banding. Examples of time evolutions of the spatial distribution of the shear displacement between the interior of the shear band and the essentially nondeforming material outside are presented. Finally, a simple relation between evolution of shear stress, displacement, shear-band width, and temperature rise during runaway instability is given.

Braeck, S.; Podladchikov, Y. Y.; Medvedev, S.

2009-10-01

427

Elastic proteins: biological roles and mechanical properties.  

PubMed Central

The term 'elastic protein' applies to many structural proteins with diverse functions and mechanical properties so there is room for confusion about its meaning. Elastic implies the property of elasticity, or the ability to deform reversibly without loss of energy; so elastic proteins should have high resilience. Another meaning for elastic is 'stretchy', or the ability to be deformed to large strains with little force. Thus, elastic proteins should have low stiffness. The combination of high resilience, large strains and low stiffness is characteristic of rubber-like proteins (e.g. resilin and elastin) that function in the storage of elastic-strain energy. Other elastic proteins play very different roles and have very different properties. Collagen fibres provide exceptional energy storage capacity but are not very stretchy. Mussel byssus threads and spider dragline silks are also elastic proteins because, in spite of their considerable strength and stiffness, they are remarkably stretchy. The combination of strength and extensibility, together with low resilience, gives these materials an impressive resistance to fracture (i.e. toughness), a property that allows mussels to survive crashing waves and spiders to build exquisite aerial filters. Given this range of properties and functions, it is probable that elastic proteins will provide a wealth of chemical structures and elastic mechanisms that can be exploited in novel structural materials through biotechnology.

Gosline, John; Lillie, Margo; Carrington, Emily; Guerette, Paul; Ortlepp, Christine; Savage, Ken

2002-01-01

428

Electrical energy and cost savings potential at DOD facilities  

SciTech Connect

The US Department of Defense (DOD) has been mandated to reduce energy consumption and costs by 20% from 1985 to 2000 and by 30% from 1985 to 2005. Reduction of electrical energy consumption at DOD facilities requires a better understanding of energy consumption patterns and energy and financial savings potential. This paper utilizes two independent studies--EDA (End-Use Disaggregation Algorithm) and MEIP (Model Energy Installation Program)--and whole-installation electricity use data obtained from a state utility to estimate electrical energy conservation potential (ECP) and cost savings potential (CSP) at the Fort Hood, Texas, military installation and at DOD nationwide. At Fort Hood, the authors estimated an annual electricity savings of 62.2 GWh/yr (18%), a peak demand savings of 10.1 MW (14%), and an annual energy cost savings of $6.5 million per year. These savings could be attained with an initial investment of $41.1 million, resulting in a simple payback of 6.3 years. Across the DOD, they estimated an annual electricity savings of 4,900 GWh/yr, a peak demand savings of 694 MW, and an annual energy cost savings of $316 million per year. The estimated cost savings is 16% of the total nationwide DOD 1993 annual energy costs. These savings could be attained with an initial investment of $1.23 billion, resulting in a simple payback of 3.9 years.

Konopacki, S.; Akbari, H. [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.; Lister, L.; DeBaille, L. [Army Construction Engineering Research Labs., Champaign, IL (United States)

1996-06-01

429

Energy potential of municipal solid waste is limited  

SciTech Connect

Energy recovery from municipal solid waste has the potential for making only a limited contribution to the nation`s overall energy production. Although the current contribution of waste-derived energy production is less than one-half of 1 percent of the nation`s total energy Supply, DOE has set a goal for energy from waste at 2 percent of the total supply by 2010. The industry`s estimates show a smaller role for waste as an energy source in the future. The energy potential from waste is limited not only by the volume and energy content of the waste itself, but also by the factors affecting the use of waste disposal options, including public opposition and the availability of financing. Energy production from waste combustors and from landfill gases generates pollutants, although these are reduced through current regulations that require the use of emissions control technology and define operational criteria for the facilities. Although DOE estimates that one-third of the energy available from waste is available in the form of energy savings through the recycling of materials, the Department`s research in this area is ongoing.

NONE

1994-09-01

430

Absolute Elastic Electron Scattering from Benzene  

NASA Astrophysics Data System (ADS)

Absolute differential cross-sections for vibrationally elastic electron scattering from benzene (C_6H_6) have been measured, for the first time, in the energy range from 4 to 20 eV and for scattering angles between 15^o and 130^o, using a crossed-beam apparatus. The cross-sections are characterised by strong forward-angle scattering due to the large dipole polarizability of the molecule and large-angle oscillations due to the effect of shape resonances. Favourable comparisons are made with a recent theoretical calculation^1 which uses a parameter-free, exact-static-exchange-correlation-polarization (SECP) potential to treat the electron-molecule interaction in all scattering symmetries. To our knowledge, this is the only contemporary calculation of differential elastic electron-C_6H6 scattering. ^1F.A. Gianturco and R.R. Lucchese, J. Chem. Phys. 108 6144, (1998)

Gulley, Robert; Buckman, Stephen

1999-10-01

431

Collective states and elastic nucleon-nucleus scattering  

Microsoft Academic Search

The connection between singularities of the elastic scattering amplitude and the self-energy which are due to collective excitations is discussed. It is shown that a pole of the self-energy will normally lead to a close-lying resonance pole of the scattering amplitude. The significance of this fact for a phenomenological optical potential is pointed out. The Weinberg method is proposed for

W. D. Heiss

1973-01-01

432

Determination of ionized hydrogen plus Cs\\/6s\\/ potential from differential cross section measurements at energies 13.4-24.2 eV  

Microsoft Academic Search

Measurements of the elastic differential cross section for the scattering of ionized hydrogen by Cs in the energy range from 13.4 to 24.2 eV are presented. A best Morse potential for the state Cs(6s) plus ionized hydrogen is determined by fitting calculated semiclassical differential cross sections with the experimental data. The accuracy of the procedure and the effect of the

H. Scheidt; G. Spiess; A. Valance; P. Pradel

1978-01-01

433

The Optimal Elastic Flagellum  

NASA Astrophysics Data System (ADS)

We address the question of optimality for slender swimming bodies or flagella in viscous fluid environments. Our novel approach is to define an energy which includes not only the work performed against the surrounding fluid, but also the energy stored elastically in the bending of the body, the energy stored elastically in internal shearing (such as the relative sliding of microtubules internal to a flagellum), and viscous dissipation due to the presence of an internal fluid. The shape of the optimal periodic planar wave is determined numerically and in some cases analytically which maximizes a related efficiency measure. We find that bending or internal dissipation costs regularize the optimal shape, but elastic shearing costs do not. For bodies of finite length, we show that the number of wavelengths expressed by the body is determined by a competition between bending costs and the work done on the fluid associated with body rotations. The hydrodynamic efficiency is shown to be less sensitive to the morphology than the bending costs, which may help us to better understand the locomotory forms observed in nature.

Spagnolie, Saverio; Lauga, Eric

2009-11-01

434

Potential impact of energy farming for conserving the fossil-fuel energy requirements of food production  

Microsoft Academic Search

The potential of supplying the energy requirements for food production by utilizing waste biomass was investigated. It was found that the energy available was more than sufficient even after conversion of waste biomass to more versatile fuel forms. The concept of utilizing waste biomass has the potential for conserving fossil fuels. Only the energy balance aspects of utilizing waste biomass

R. C. Bailie; D. M. Doner; J. D. Henry

1976-01-01

435

Hopf solitons and elastic rods  

NASA Astrophysics Data System (ADS)

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.

Harland, Derek; Speight, Martin; Sutcliffe, Paul

2011-03-01

436

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

SciTech Connect

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.)

Webber, Carrie A.; Brown, Richard E.

1998-06-19

437

Optimizing potential energy functions for maximal intrinsic hyperpolarizability  

NASA Astrophysics Data System (ADS)

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 ?xxxint than higher-dimensional systems.

Zhou, Juefei; Szafruga, Urszula B.; Watkins, David S.; Kuzyk, Mark G.

2007-11-01

438

Global Onshore Wind Energy Potential and Its Uncertainties  

NASA Astrophysics Data System (ADS)

Wind power, a clean and renewable energy resource, can play an important role in providing energy and reducing greenhouse gas emissions. Yet there are substantial and important uncertainties about the potential costs and supplies of wind that influence our ability to understand today the strategic role of wind power in the future. A detailed global assessment of onshore wind energy potential and its uncertainties will help decision-makers develop policies and strategies to meet energy and environmental goals. In this study, we assess the technical and economic potential of onshore wind energy and its spatial distribution using reanalysis wind speed data from the National Centers for Environmental Modeling (Figure 1). The study focuses in particular in exploring a range of uncertainties that impact the economic potential of wind power by constructing quantitative scenarios for eight key physical and economic parameters. We present quantification of the impact of uncertainties in these parameters, focusing on areas relevant to geoscience research (Figure 2). The amount of economic potential of wind energy depends strongly on several uncertain parameters such as wind speed, turbine cost, and land-suitability. The distribution of wind speed at fine temporal and spatial scales is a key parameter, but is not well quantified in many regions of the world. Reanalysis datasets with more accurate wind fields are a first step, along with computationally tractable downscaling methodologies. Another key assumption is land-suitability, which is the fraction of a particular land-cover type assumed to be available for wind farm development. There is currently little scientific basis for land-suitability assumptions. While some of the data needed for progress in these areas is readily available, such as high-resolution land-cover and terrain data, further advances are likely to require new methodologies and inter-disciplinary collaboration. We outline a number of areas where further research is needed to construct improved estimates of global wind energy potential.

Zhou, Y.; Clarke, L.; Luckow, P.; Smith, S.

2011-12-01

439

Elastic constants of a Laves phase compound: C15 NbCr{sub 2}  

SciTech Connect

The single-crystal elastic constants of C15 NbCr{sub 2} have been computed by using a first-principles, self-consistent, full-potential total energy method. From these single-crystal elastic constants the isotropic elastic moduli are calculated using the Voigt and Reuss averages. The calculated values are in fair agreement with the experimental values. The implications of the results are discussed with regards to Poisson`s ratio and the direction dependence of Young`s modulus.

Ormeci, A. [Koc Univ., Istanbul (Turkey)]|[Los Alamos National Lab., NM (United States); Chu, F.; Wills, J.M.; Chen, S.P.; Albers, R.C.; Thoma, D.J.; Mitchell, T.E. [Los Alamos National Lab., NM (United States)

1997-04-01

440

Hydroelastic response and energy harvesting potential of flexible piezoelectric beams in viscous flow  

NASA Astrophysics Data System (ADS)

Electroactive polymers such as piezoelectric elements are able to generate electric potential differences from induced mechanical deformations. They can be used to build devices to harvest ambient energy from natural flow-induced deformations, e.g., as flapping flags subject to flowing wind or artificial seaweed subject to waves or underwater currents. The objectives of this study are to (1) investigate the transient hydroelastic response and energy harvesting potential of flexible piezoelectric beams fluttering in incompressible, viscous flow, and (2) identify critical non-dimensional parameters that govern the response of piezoelectric beams fluttering in viscous flow. The fluid-structure interaction response is simulated using an immersed boundary approach coupled with a finite volume solver for incompressible, viscous flow. The effects of large beam deformation, membrane tension, and coupled electromechanical responses are all considered. Validation studies are shown for the motion of a flexible filament in uniform flow, and for a piezoelectric beam subject to base vibration. The predicted flutter velocities and frequencies also compared well with published experimental and numerical data over a range of Reynolds numbers for varying fluid and solid combinations. The results showed that for a heavy beam in a light fluid (i.e., high ?? regime), flutter incepts at a lower critical speed with a lower reduced frequency than for a light beam in a heavy fluid (i.e., low ?? regime). In the high ?? regime, flutter develops at the second mode and is only realized when the fluid inertial forces are in balance with the solid elastic restoring forces, which leads to large amplitude oscillations and complex wake patterns; the flutter speed is practically independent of the Reynolds number (Re) and solid to fluid mass ratio (??), because the response is dominated by the solid inertial forces. In the low ?? regime, fluid inertial forces dominate, flutter develops at higher modes and is only realized when the solid inertial forces are proportioned to the solid elastic restoring forces; the flutter speed depends on both Re and ??, and viscous force and beam tension effects tend to delay flutter and reduce vibration amplitudes, leading to thinner, more simplified wake patterns. The results demonstrate that energy extraction via fluttering piezoelectric beams is possible. The overall efficiency was observed to be influenced by the piezoelectric circuit resistance, which is known to be directly related to the square of the piezoelectric coupling factor. The results show that the maximum strain limit of piezoelectrics may be exceeded, and hence careful optimization of the material and geometry is recommended to maximize the energy capture for a given range of expected flow conditions while satisfying safety and reliability requirements.

Akcabay, Deniz Tolga; Young, Yin Lu

2012-05-01

441

Energy dependence of T/sub 20/ and tau/sub 21/ in. pi. d-italic-arrow-right elastic scattering  

SciTech Connect

Angular distributions of the tensor analyzing powers T/sub 20/ and tau/sub 21/ have been measured for ..pi..d-italic-arrow-right elastic scattering, in a single scattering experiment employing a tensor polarized deuteron target. Measurements of T/sub 20/ were obtained for pion bombarding energies of 134, 151, 180, 220, and 256 MeV. Measurements of tau/sub 21/ were obtained for pion bombarding energies of 134, 180, and 220 MeV. The results are compared with three-body calculations where effects relating to pion absorption are seen to play an important role.

Smith, G.R.; Gill, D.R.; Healey, D.; Ottewell, D.; Wait, G.D.; Walden, P.; Johnson, R.R.; Jones, G.; Olszewski, R.; Rozon, F.M.; and others

1988-11-20

442

Energy dependence of T/sub 20/ and tau/sub 21/ in. pi. d-italic-arrow-right elastic scattering  

SciTech Connect

Angular distributions of the tensor analyzing powers T/sub 20/ and tau/sub 21/ have been measured for ..pi..d elastic scattering, in a single scattering experiment employing a tensor polarized deuteron target. Measurements of T/sub 20/ were obtained for pion bombarding energies of 134, 151, 180, 220, and 256 MeV. Measurements of tau/sub 21/ were obtained for pion bombarding energies of 134, 180, and 220 MeV. The results are compared with three-body calculations where effects relating to pion absorption are seen to play an important role.

Smith, G.R.; Gill, D.R.; Healey, D.; Ottewell, D.; Wait, G.D.; Walden, P.; Johnson, R.R.; Jones, G.; Olszewski, R.; Rozon, F.M.; and others

1988-07-01

443

Dynamics of oxygen in the YBa sub 2 Cu sub 3 O sub 7 minus x basal planes by elastic-energy-loss measurements  

Microsoft Academic Search

We report elastic-energy-dissipation measurements in YBaâCuâO{sub 7-{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

G. Cannelli; R. Cantelli; F. Cordero; M. Ferretti; L. Verdini

1990-01-01

444

Wave Response during Hydrostatic and Geostrophic Adjustment. Part II: Potential Vorticity Conservation and Energy Partitioning.  

NASA Astrophysics Data System (ADS)

This second part of a two-part study of the hydrostatic and geostrophic adjustment examines the potential vorticity and energetics of the acoustic waves, buoyancy waves, Lamb waves, and steady state that are generated following the prescribed injection of heat into an isothermal atmosphere at rest. The potential vorticity is only nonzero for the steady class and depends only on the spatial and time-integrated properties of the injection. The waves contain zero net potential vorticity, but undergo a time-dependent vorticity exchange involving latent and relative vorticities.The energy associated with a given injection may be partitioned distinctly among the various wave classes. The characteristics of this partitioning depend on the spatiotemporal detail of the injection, as well as whether the imbalance is generated by injection of heat, mass, or momentum. Spatially, waves of a scale similar to that of the injection are preferentially excited. Temporally, an extended duration injection preferentially filters high-frequency waves. An instantaneous injection, that is, the temporal Green's function, contains the largest proportions of the high-frequency waves.The proportions of kinetic, available elastic, and available potential energies that are carried by the various waves are functions of the homogeneous system. For example, deep buoyancy waves of small horizontal scale primarily contain equal portions of available potential and vertical kinetic energy. The steady state contains more available potential energy than kinetic energy at small horizontal scale, and vice versa. These qualities of the wave energetics illustrate the mechanisms that characterize the physics of each wave class.The evolution and spectral partitioning of the energetics following localized warmings identical to those in Part I are presented in order to illustrate some of these basic properties of the energetics. For example, a heating lasting longer than a few minutes does not excite acoustic waves. However, Lamb waves of wide horizontal scale can be excited by a heating of several hours. The first buoyancy waves to be filtered by an extended duration heating are those of the deepest and narrowest structure that have a frequency approaching the buoyancy frequency. The energetics of the steady state depends only on the spatial and time-integrated properties of the warming. However, the energetics and transient evolution toward a given steady state depend on the temporal properties of the warming and may differ widely.

Chagnon, Jeffrey M.; Bannon, Peter R.

2005-05-01

445

The Elastic Field Outside an Ellipsoidal Inclusion  

Microsoft Academic Search

The results of an earlier paper are extended. The elastic field outside an inclusion or in- homogeneity is treated in greater detail. For a general inclusion the harmonic potential of a certain surface distribution may be used in place of the biharmonic potential used pre- viously. The elastic field outside an ellipsoidal inclusion or inhomogeneity may be expressed entirely in

J. D. Eshelby

1959-01-01

446

Saturation wind power potential and its implications for wind energy  

PubMed Central

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.

Jacobson, Mark Z.; Archer, Cristina L.

2012-01-01

447

Potential energy production from algae on marginal land in China.  

PubMed

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

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

2011-08-31

448

Ultracold collisions between two light indistinguishable diatomic molecules: Elastic and rotational energy transfer in HD+HD  

NASA Astrophysics Data System (ADS)

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.

Sultanov, Renat A.; Guster, Dennis; Adhikari, S. K.

2012-05-01

449

Fossil energy savings potential of sugar cane bio-energy systems  

Microsoft Academic Search

One important rationale for bio-energy systems is their potential to save fossil energy. Converting a conventional sugar mill into a bio-energy process plant would contribute to fossil energy savings via the extraction of renewable electricity and ethanol substituting for fossil electricity and gasoline, respectively. This paper takes a closer look at the Thai sugar industry and examines two practical approaches

Thu Lan T. Nguyen; John E. Hermansen; Masayuki Sagisaka

2009-01-01

450

Modeling energy-conservation potentials of community energy-system technologies  

NASA Astrophysics Data System (ADS)

A mathematical model is presented for estimating energy-conservation potentials of community-energy-system technologies in meeting community energy service demands. The model is formulated to identify optimal community composition, technology choices, and fuel use under various fuel price, energy service demand, and other system-parameter assumptions.

Kleeman, P. I.

1981-06-01

451

Constraints on the redshift dependence of the dark energy potential  

SciTech Connect

We develop a formalism to characterize the shape and the redshift evolution of the dark energy potential. Our formalism makes use of quantities similar to the horizon-flow parameters in inflation and is general enough that can deal with multiscalar quintessence scenarios, exotic matter components, and higher-order curvature corrections to General Relativity. We show how the shape of the dark energy potential can be recovered nonparametrically using this formalism and we present approximations analogous to the ones relevant to slow-roll inflation. Since presently available data do not allow a nonparametric and exact reconstruction of the potential, we consider a general parametric description. This reconstruction can also be used in other approaches followed in the literature (e.g., the reconstruction of the redshift evolution of the dark energy equation of state w(z)). Using observations of passively evolving galaxies and supernova data we derive constraints on the dark energy potential shape in the redshift range 0.1potential is consistent with being constant, although at the same level of confidence variations cannot be excluded with current data. We forecast constraints achievable with future data from the Atacama Cosmology Telescope.

Simon, Joan; Verde, Licia; Jimenez, Raul [Dept. of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, Pennsylvania 19104 (United States)

2005-06-15

452

Interionic Potential and Stacking Fault Energy of Copper  

NASA Astrophysics Data System (ADS)

Formation energy of an intrinsic stacking fault in copper is calculated by the use of two interionic potential functions given by Prakash and Lucasson. A modified Ewald method is used to calculate lattice sum of long-range interionic potentials expressed by Vp \\sin\\cos(2kFr)/(2kFr)3. Numerical results show that 1) the two potential functions give 60.5 erg/cm2 and 78.3 erg/cm2 to the intrinsic stacking fault energy, and 2) the energy comes mainly from a long-range interaction but not from a short-range one. These potentials are used also for calculations of binding energies of fcc, bcc and hcp structures. Numerical results show that the fcc structure is stable and the binding energies of the bcc and the hcp structures are larger than that of the fcc by 0.06 eV/ion and 0.01 eV/ion, respectively.

Sugiyama, Akira

1982-04-01

453

Elastic wave analysis for broken rail detection  

Microsoft Academic Search

A technique is presented to identify broken rail. The technique is based on elastic guided wave propagation through the rail. Broken rail detection is possible by either utilizing an impact device or energy propagating from the train wheel in contact with the rail. In principle, elastic guided wave energy propagates along the track, a natural wave-guide, until a broken rail

Joseph L. Rose; Michael J. Avioli; Younho Cho

2002-01-01

454

Assessment of wind energy potential in Gaza Strip  

Microsoft Academic Search

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

Juma Yousuf Alaydi

2011-01-01

455

Calculation of potential energy surfaces using explicitly correlated methods  

NASA Astrophysics Data System (ADS)

Recent developments in explicitly correlated wavefunctions mean that highly accurate potential energy surfaces for small molecules can be obtained with a low computational cost. Key components of these composite surfaces will be presented, including extrapolation of explicitly correlated CCSD(T) correlation energies and correcting for core-valence correlation effects using F12 methods. Recent applications will be highlighted, including high-resolution spectroscopy of CCN, CCO^+ and COC^+.

Hill, Grant; Peterson, Kirk A.

2010-03-01

456

Reaction Path Optimization with Holonomic Constraints and Kinetic Energy Potentials  

SciTech Connect

Two methods are developed to enhance the stability, efficiency, and robustness of reaction path optimization using a chain of replicas. First, distances between replicas are kept equal during path optimization via holonomic constraints. Finding a reaction path is, thus, transformed into a constrained optimization problem. This approach avoids force projections for finding minimum energy paths (MEPs), and fast-converging schemes such as quasi-Newton methods can be readily applied. Second, we define a new objective function - the total Hamiltonian - for reaction path optimization, by combining the kinetic energy potential of each replica with its potential energy function. Minimizing the total Hamiltonian of a chain determines a minimum Hamiltonian path (MHP). If the distances between replicas are kept equal and a consistent force constant is used, then the kinetic energy potentials of all replicas have the same value. The MHP in this case is the most probable isokinetic path. Our results indicate that low-temperature kinetic energy potentials (<5 K) can be used to prevent the development of kinks during path optimization and can significantly reduce the required steps of minimization by 2-3 times without causing noticeable differences between a MHP and MEP. These methods are applied to three test cases, the C?eq-to-Cax isomerization of an alanine dipeptide, the ?C?- to-¹C? transition of an ?-D-glucopyranose, and the helix-to-sheet transition of a GNNQQNY heptapeptide. By applying the methods developed in this work, convergence of reaction path optimization can be achieved for these complex transitions, involving full atomic details and a large number of replicas (>100). For the case of helix-to-sheet transition, we identif