Global Optical Potential for the Elastic Scattering of $^{6}$He at Low Energies
Y. Kucuk; I. Boztosun; T. Topel
2009-11-20
A set of global optical potential has been derived to describe the interactions of $^{6}$He at low energies. The elastic scattering angular distribution data measured so far for many systems, ranging from $^{12}$C to $^{209}$Bi, have been considered within the framework of the optical model in order to find a global potential set to describe the experimental data consistently. We report that very good agreement between theoretical and experimental results has been obtained with small $\\chi^{2}/N$ values by using the derived potential set. The reaction cross section and volume integrals of the potentials have been deduced from the theoretical calculations for all studied systems at relevant energies.
Elastic alpha scattering experiments and the alpha-nucleus optical potential at low energies
Mohr, P.; Kiss, G.G.; Fülöp, Zs.; Galaviz, D.; Gyürky, Gy.; Somorjai, E.
2013-11-15
High precision angular distribution data of (?,?) elastic scattering are presented for the nuclei {sup 89}Y, {sup 92}Mo, {sup 106,110,116}Cd, {sup 112,124}Sn, and {sup 144}Sm at energies around the Coulomb barrier. Such data with small experimental uncertainties over the full angular range (20–170°) are the indispensable prerequisite for the extraction of local optical potentials and for the determination of the total reaction cross section ?{sub reac}. A systematic fitting procedure was applied to the experimental scattering data presented to obtain comprehensive local potential parameter sets that are composed of a real folding potential and an imaginary potential of Woods–Saxon surface type. The potential parameters obtained were used in turn to construct a new systematic ?-nucleus potential with very few parameters. Although this new potential cannot reproduce the angular distributions with the same small deviations as the local potential, the new potential is able to predict the total reaction cross sections for all cases under study.
Elastic alpha scattering experiments and the alpha-nucleus optical potential at low energies
P. Mohr; G. G. Kiss; Zs. Fülöp; D. Galaviz; Gy. Gyürky; E. Somorjai
2012-12-12
High precision angular distribution data of ($\\alpha$,$\\alpha$) elastic scattering are presented for the nuclei $^{89}$Y, $^{92}$Mo, $^{106,110,116}$Cd, $^{112,124}$Sn, and $^{144}$Sm at energies around the Coulomb barrier. Such data with small experimental uncertainties over the full angular range (20-170 degrees) are the indispensable prerequisite for the extraction of local optical potentials and for the determination of the total reaction cross section $\\sigma_{\\rm{reac}}$. A systematic fitting procedure was applied to the presented experimental scattering data to obtain comprehensive local potential parameter sets which are composed of a real folding potential and an imaginary potential of Woods-Saxon surface type. The obtained potential parameters were used in turn to construct a new systematic $\\alpha$-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.
M. Avrigeanu; A. C. Obreja; F. L. Roman; V. Avrigeanu; W. von Oertzen
2008-08-05
A previously derived semi-microscopic analysis based on the Double Folding Model, for alpha-particle elastic scattering on A~100 nuclei at energies below 32 MeV, is extended to medium mass A ~ 50-120 nuclei and energies from ~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 concerned target nuclei from 45Sc to 118Sn and incident energies below ~12 MeV. The former diffuseness of the real part of optical potential as well as the surface imaginary-potential depth have been found responsible for the actual difficulties in the description of these data, and modified in order to obtain an optical potential which describe equally well both the low energy elastic-scattering and induced-reaction data of alpha-particles.
Liu, Guanlin; Leng, Qiang; Lian, Jiawei; Guo, Hengyu; Yi, Xi; Hu, Chenguo
2015-01-21
Great attention has been paid to nanogenerators that harvest energy from ambient environments lately. In order to give considerable output current, most nanogenerators require high-velocity motion that in most cases can hardly be provided in our daily life. Here we report a notepad-like triboelectric generator (NTEG), which uses simple notepad-like structure to generate elastic deformation so as to turn a low-velocity kinetic energy into high-velocity kinetic energy through the conversion of elastic potential energy. Therefore, the NTEG can achieve high current output under low-velocity motion, which completely distinguishes it from tribogenerators previously reported. The factors that may affect the output performance are explored, including the number of slices, active length of slice, press speed, and vertical displacement. In addition, the working mechanism is systematically studied, indicating that the efficiency of the generator can be greatly enhanced by interconversion between kinetic energy and elastic potential energy. The short-circuit current, the open-circuit voltage, and power density are 205 ?A and 470 V and 9.86 W/m(2), respectively, which is powerful enough to light up hundreds of light-emitting diodes (LEDs) and charge a commercial capacitor. Besides, NTEGs have been successfully applied to a self-powered door monitor. PMID:25564956
NASA Astrophysics Data System (ADS)
Lee, Teck-Ghee; Rochow, C.; Martin, R.; Clark, T. K.; Forrey, R. C.; Balakrishnan, N.; Stancil, P. C.; Schultz, D. R.; Dalgarno, A.; Ferland, Gary J.
2005-01-01
The two most recently published potential energy surfaces (PESs) for the HeH2 complex, the so-called MR (Muchnick and Russek) and BMP (Boothroyd, Martin, and Peterson) surfaces, are quantitatively evaluated and compared through the investigation of atom-diatom collision processes. The BMP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the PES compared to that of the MR surface. We found significant differences in inelastic rovibrational cross sections computed on the two surfaces for processes dominated by large changes in target rotational angular momentum. In particular, the H2(?=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.
Power, Archie Dayton
1912-06-01
ELASTICITY CELLS. AN INVESTIGATION OF THE RELATION BETWEEN THE ENERGY LIBERATED BY A STRAINED METAL GOING INTO SOLUTION, AND THE POTENTIAL DIFFERENCE RESULTING. A thesis submitted to the Department of Physios of the University of Kansas..., in partial fulfilment of the requirements for the Degree of Master of Arts. By A. D. Power, June, 1912. T R00107 48121 After looking about for a subject suitable for experimental work to obtain material for a thesis It was decided to investigate...
W. Y. So; T. Udagawa; K. S. Kim; S. W. Hong; B. T. Kim
2006-12-13
Based on the extended optical model approach in which the polarization potential is decomposed into direct reaction (DR) and fusion parts, simultaneous $\\chi^{2}$ analyses are performed for elastic scattering and fusion cross section data for the $^{6}$Li+$^{208}$Pb system at near-Coulomb-barrier energies. A folding potential is used as the bare potential. It is found that the real part of the resultant DR part of the polarization potential is repulsive, which is consistent with the results from the Continuum Discretized Coupled Channel (CDCC) calculations and the normalization factors needed for the folding potentials. Further, it is found that both DR and fusion parts of the polarization potential satisfy separately the dispersion relation.
NSDL National Science Digital Library
2010-01-01
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.
W. Y. So; T. Udagawa; S. W. Hong; B. T. Kim
2008-01-15
Simultaneous $\\chi^{2}$ analyses are performed for elastic scattering and fusion cross section data for the $^{12}$C+$^{208}$Pb system at near-Coulomb-barrier energies by using the extended optical model approach in which the polarization potential is decomposed into direct reaction (DR) and fusion parts. Use is made of the double folding potential as a bare potential. It is found that the experimental elastic scattering and fusion data are well reproduced without introducing any normalization factor for the double folding potential and also that both DR and fusion parts of the polarization potential determined from the $\\chi^{2}$ analyses satisfy separately the dispersion relation. Furthermore, it is shown that the imaginary parts of both DR and fusion potentials at the strong absorption radius change very rapidly, which results in a typical threshold anomaly in the total imaginary potential as observed with tightly bound projectiles such as $\\alpha$-particle and $^{16}$O.
?N Elastic Scattering and Resonances in Quark Potential Model
NASA Astrophysics Data System (ADS)
Wang, Hai-Jun; Su, Jun-Chen
2008-04-01
The quark potential model is used to investigate the low-energy elastic scattering of ?N system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator confining potential. By means of the resonating group method, a nonlocal effective potential for the ?N system is derived from the interquark potentials and used to calculate the ?N elastic scattering phase shifts. By considering the effect of QCD renormalization, the suppression of the spin-orbital coupling and the contribution of the color octet of the clusters (qbar q) and (qqq), the numerical results are in fairly good agreement with the experimental data. The same model and method are employed to investigate the possible ?N resonances. For this purpose, the resonating group equation is transformed into a standard Schrödinger equation in which the nonlocal effective ?N interaction potential is included. Solving the Schrödinger equation by the variational method, we are able to reproduce the masses of some currently concerned ?N resonances.
High energy elastic and diffractive scattering
Shukla, S.
1992-08-01
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.
W. Y. So; T. Udagawa; K. S. Kim; S. W. Hong; B. T. Kim
2007-06-05
Simultaneous $\\chi^{2}$ analyses previously made for elastic scattering and fusion cross section data for the $^{6}$Li+$^{208}$Pb system is extended to the $^{7}$Li+$^{208}$Pb system at near-Coulomb-barrier energies based on the extended optical model approach, in which the polarization potential is decomposed into direct reaction (DR) and fusion parts. Use is made of the double folding potential as a bare potential. It is found that the experimental elastic scattering and fusion data are well reproduced without introducing any normalization factor for the double folding potential and that both the DR and fusion parts of the polarization potential determined from the $\\chi^{2}$ analyses satisfy separately the dispersion relation. Further, we find that the real part of the fusion portion of the polarization potential is attractive while that of the DR part is repulsive except at energies far below the Coulomb barrier energy. A comparison is made of the present results with those obtained from the Continuum Discretized Coupled Channel (CDCC) calculations and a previous study based on the conventional optical model with a double folding potential. We also compare the present results for the $^7$Li+$^{208}$Pb system with the analysis previously made for the $^{6}$Li+$^{208}$Pb system.
Kaur, Gurpreet; Jhingan, A; Sugathan, P; Hagino, K
2015-01-01
We discuss the role of channel coupling in the surface properties of an inter-nuclear potential for heavy-ion reactions. To this end, we analyze the experimental quasi-elastic cross sections for the $^{12}$C + $^{105,106}$Pd and $^{13}$C + $^{105,106}$Pd systems using the coupled-channels approach by including the vibrational excitations in the target nuclei. While earlier studies have reported a negligible influence of vibrational excitation on the surface diffuseness parameter for spherical systems, we find a significant effect for the C+Pd systems. Our systematic study also reveals influence of transfer couplings on the surface diffuseness parameter.
Series Elastic Actuation: Potential and Pitfalls
Hurst, Jonathan
and the associated energy storage patterns typical for a running gait. However, in comparison to a load cell (a that are capable of storing an amount of energy comparable to that associated with a typical impact can be tuned system. This strategy follows that of animals, who store gait energy in springy tendons[2], [3], [4], [5
Elastic epsilon/sup + -/-He scattering with the use of the model-potential method
Khan, P.; Datta, S.K.; Bhattacharyya, D.; Ghosh, A.S.
1984-06-01
A model-potential method has been used to evaluate the elastic e/sup + -/-He scattering at the low-incident energies. The potential contains one parameter to include the effect of short-range correlation. The results for the elastic e/sup + -/-He scattering have been obtained using the same parameter. Two model exchange potentials, one for s wave and the other for higher partial waves, have been employed. The present results are in good agreement with the measured values and refined theoretical predictions.
W. Y. So; T. Udagawa; K. S. Kim; S. W. Hong; B. T. Kim
2010-03-14
Based on the extended optical model with the double folding potential, in which the polarization potential is decomposed into direct reaction (DR) and fusion parts, simultaneous $\\chi^{2}$ analyses are performed of elastic scattering and fusion cross section data for the $^{9}$Be+$^{28}$Si, $^{144}$Sm, and $^{208}$Pb systems at near-Coulomb-barrier energies. We find that the real part of the resultant DR part of the polarization potential is systematically repulsive for all the targets considered, which is consistent with the results deduced from the Continuum Discretized Coupled Channel (CDCC) calculations taking into account the polarization effects due to breakup. Further, it is found that both DR and fusion parts of the extracted polarization potentials satisfy the dispersion relation.
Elastic energy of polyhedral bilayer vesicles
Haselwandter, Christoph A.; Phillips, Rob
2011-01-01
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. PMID:21797397
Elastic energy of polyhedral bilayer vesicles
Christoph A. Haselwandter; Rob Phillips
2011-06-10
In recent experiments [M. Dubois, B. Dem\\'e, T. Gulik-Krzywicki, J.-C. Dedieu, C. Vautrin, S. D\\'esert, E. Perez, and T. Zemb, Nature (London) Vol. 411, 672 (2001)] the spontaneous formation of hollow bilayer vesicles with polyhedral symmetry has been observed. On the basis of the experimental phenomenology it was suggested [M. Dubois, V. Lizunov, A. Meister, T. Gulik-Krzywicki, J. M. Verbavatz, E. Perez, J. Zimmerberg, and T. Zemb, Proc. Natl. Acad. Sci. U.S.A. Vol. 101, 15082 (2004)] that the mechanism for the formation of bilayer polyhedra is minimization of elastic bending energy. Motivated by these experiments, we study the elastic bending energy of polyhedral bilayer vesicles. In agreement with experiments, and provided that excess amphiphiles exhibiting spontaneous curvature are present in sufficient quantity, we find that polyhedral bilayer vesicles can indeed be energetically favorable compared to spherical bilayer vesicles. Consistent with experimental observations we also find that the bending energy associated with the vertices of bilayer polyhedra can be locally reduced through the formation of pores. However, the stabilization of polyhedral bilayer vesicles over spherical bilayer vesicles relies crucially on molecular segregation of excess amphiphiles along the ridges rather than the vertices of bilayer polyhedra. Furthermore, our analysis implies that, contrary to what has been suggested on the basis of experiments, the icosahedron does not minimize elastic bending energy among arbitrary polyhedral shapes and sizes. Instead, we find that, for large polyhedron sizes, the snub dodecahedron and the snub cube both have lower total bending energies than the icosahedron.
Elastic energy of polyhedral bilayer vesicles
NASA Astrophysics Data System (ADS)
Haselwandter, Christoph A.; Phillips, Rob
2011-06-01
In recent experiments [M. Dubois, B. Demé, T. Gulik-Krzywicki, J.-C. Dedieu, C. Vautrin, S. Désert, E. Perez, and T. Zemb, Nature (London)NATUAS0028-083610.1038/35079541 411, 672 (2001)] the spontaneous formation of hollow bilayer vesicles with polyhedral symmetry has been observed. On the basis of the experimental phenomenology it was suggested [M. Dubois, V. Lizunov, A. Meister, T. Gulik-Krzywicki, J. M. Verbavatz, E. Perez, J. Zimmerberg, and T. Zemb, Proc. Natl. Acad. Sci. USAPNASA60027-842410.1073/pnas.0400837101 101, 15082 (2004)] that the mechanism for the formation of bilayer polyhedra is minimization of elastic bending energy. Motivated by these experiments, we study the elastic bending energy of polyhedral bilayer vesicles. In agreement with experiments, and provided that excess amphiphiles exhibiting spontaneous curvature are present in sufficient quantity, we find that polyhedral bilayer vesicles can indeed be energetically favorable compared to spherical bilayer vesicles. Consistent with experimental observations we also find that the bending energy associated with the vertices of bilayer polyhedra can be locally reduced through the formation of pores. However, the stabilization of polyhedral bilayer vesicles over spherical bilayer vesicles relies crucially on molecular segregation of excess amphiphiles along the ridges rather than the vertices of bilayer polyhedra. Furthermore, our analysis implies that, contrary to what has been suggested on the basis of experiments, the icosahedron does not minimize elastic bending energy among arbitrary polyhedral shapes and sizes. Instead, we find that, for large polyhedron sizes, the snub dodecahedron and the snub cube both have lower total bending energies than the icosahedron.
An Expression for the Granular Elastic Energy
Yimin Jiang; Hepeng Zheng; Zheng Peng; Liping Fu; Shixiong Song; Qicheng Sun; Michael Mayer; Mario Liu
2012-06-13
Granular Solid Hydrodynamics (GSH) is a broad-ranged continual mechanical description of granular media capable of accounting for static stress distributions, yield phenomena, propagation and damping of elastic waves, the critical state, shear band, and fast dense flow. An important input of GSH is an expression for the elastic energy needed to deform the grains. The original expression, though useful and simple, has some draw-backs. Therefore, a slightly more complicated expression is proposed here that eliminates three of them: (1) The maximal angle at which an inclined layer of grains remains stable is increased from $26^\\circ$ to the more realistic value of $30^\\circ$. (2)Depending on direction and polarization, transverse elastic waves are known to propagate at slightly different velocities. The old expression neglects these differences, the new one successfully reproduces them. (3) Most importantly, the old expression contains only the Drucker-Prager yield surface. The new one contains in addition those named after Coulomb, Lade-Duncan and Matsuoka-Nakai -- realizing each, and interpolating between them, by shifting a single scalar parameter.
Elastic electron-deuteron scattering within a relativistic potential model
NASA Astrophysics Data System (ADS)
Khokhlov, N. A.; Vakulyuk, A. A.
2015-01-01
Elastic electron-deuteron scattering was considered in the point form of relativistic quantum mechanics. Observables of this process and the dependence of the deuteron form factors on the 4-momentum transfer Q up to 8 fm-1 were calculated. The nucleon-nucleon potentials used in the calculations included the Nijmegen potentials NijmI and NijmII, the Bonn potential CD-Bonn, and the Moscow potential involving forbidden states. A parametrization of the nucleon form factors that complies with present-day experimental results was used as input data. The results of the calculations that employ all of the above potential types describe experimental data at least up to Q ? 5 fm-1.
CAPITAL FOR ENERGY AND INTER-FUEL ELASTICITIES OF SUBSTITUTION
CAPITAL FOR ENERGY AND INTER- FUEL ELASTICITIES OF SUBSTITUTION FROM A TECHNOLOGY SIMULATION MODEL between capital and different forms of energy in the future. These values, the long run capital for energy, the Canadian capital for energy substitution elasticity is estimated to exhibit mild substitutability
Virtual coupling potential for elastic scattering of 10,11Be on proton and carbon targets
NASA Astrophysics Data System (ADS)
Lapoux, V.; Alamanos, N.; Auger, F.; Blumenfeld, Y.; Casandjian, J.-M.; Chartier, M.; Cortina-Gil, M. D.; Fékou-Youmbi, V.; Gillibert, A.; Cormick, M. Mac; Maréchal, F.; Marie, F.; Mittig, W.; de Oliveira Santos, F.; Orr, N. A.; Ostrowski, A. N.; Ottini-Hustache, S.; Roussel-Chomaz, P.; Scarpaci, J.-A.; Sida, J.-L.; Suomijärvi, T.; Winfield, J. S.
2008-01-01
The 10,11Be(p, p) and (12C, 12C) reactions were analyzed to determine the influence of the weak binding energies of exotic nuclei on their interaction potential. The elastic cross sections were measured at GANIL in inverse kinematics using radioactive 10,11Be beams produced at energies of 39.1A and 38.4 A MeV. The elastic proton scattering data were analyzed within the framework of the microscopic Jeukenne-Lejeune-Mahaux (JLM) nucleon-nucleus potential. The angular distributions are found to be best reproduced by reducing the real part of the microscopic optical potential, as a consequence of the coupling to the continuum. These effects modify deeply the elastic potential. Including the Virtual Coupling Potential (VCP), we show the ability of the general optical potentials to reproduce the data for scattering of unstable nuclei, using realistic densities. Finally, the concepts needed to develop a more general and microscopic approach of the VCP are discussed.
Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities
NASA Astrophysics Data System (ADS)
Baylin-Stern, Adam C.
This paper demonstrates how an U.S. application of CIMS, a technologically explicit and behaviourally realistic energy-economy simulation model which includes macro-economic feedbacks, can be used to derive estimates of elasticity of substitution (ESUB) and autonomous energy efficiency index (AEEI) parameters. The ability of economies to reduce greenhouse gas emissions depends on the potential for households and industry to decrease overall energy usage, and move from higher to lower emissions fuels. Energy economists commonly refer to ESUB estimates to understand the degree of responsiveness of various sectors of an economy, and use estimates to inform computable general equilibrium models used to study climate policies. Using CIMS, I have generated a set of future, 'pseudo-data' based on a series of simulations in which I vary energy and capital input prices over a wide range. I then used this data set to estimate the parameters for transcendental logarithmic production functions using regression techniques. From the production function parameter estimates, I calculated an array of elasticity of substitution values between input pairs. Additionally, this paper demonstrates how CIMS can be used to calculate price-independent changes in energy-efficiency in the form of the AEEI, by comparing energy consumption between technologically frozen and 'business as usual' simulations. The paper concludes with some ideas for model and methodological improvement, and how these might figure into future work in the estimation of ESUBs from CIMS. Keywords: Elasticity of substitution; hybrid energy-economy model; translog; autonomous energy efficiency index; rebound effect; fuel switching.
The role of elastic energy storage and recovery in downhill and uphill running.
Snyder, Kristine L; Kram, Rodger; Gottschall, Jinger S
2012-07-01
In level running, humans and other animals store and recover elastic energy during each step. What role does elastic energy play during downhill and uphill running? We measured the fluctuations of the mechanical energy of the center of mass (CoM) of 15 human participants running at 3 m s(-1) on the level, downhill and uphill on a force-measuring treadmill mounted at 3, 6 and 9 deg. In level running, nearly symmetrical decreases and increases of the combined gravitational potential and kinetic (GPE+KE) energy of the CoM indicated equal possible elastic energy storage and recovery. However, asymmetrical fluctuations during hill running indicate reduced maximum possible elastic energy storage and return. We analyzed mechanical energy generation and dissipation during level and hill running by quantifying the anatomically estimated elastic energy storage (AEEE) in the arch and Achilles' tendon using peak ground reaction forces and anatomical characteristics. AEEE did not change with grade. At shallow downhill grades, the body must generate mechanical energy, though it dissipates more than it generates. At steeper downhill grades, little to no energy generation is required and only mechanical energy dissipation must occur. The downhill grade at which mechanical energy must no longer be generated occurs at approximately -9 deg, near the metabolically optimal running grade. At shallow uphill grades, mechanical energy must be generated to raise the CoM, and at steeper grades, additional energy must be generated to offset reduced elastic energy storage and return. PMID:22675189
Net Balanced Floorplanning Based on Elastic Energy Model
Nannarelli, Alberto
Net Balanced Floorplanning Based on Elastic Energy Model Wei Liu and Alberto Nannarelli Dept variations can introduce extra signal skew, it is desirable to have floorplans with balanced net delays based on the elastic energy model. The B*-tree, which is based on an ordered binary tree, is used
Elastic Energy Transfer in Turbulence of Dilute Polymer Solution
NASA Astrophysics Data System (ADS)
Xi, Heng-Dong; Bodenschatz, Eberhard; Xu, Haitao
2012-11-01
We present an experimental study of the energy transfer in the bulk of a turbulent flow with small amount long-chain polymer additives. By varying the Reynolds numbers R?, Wissenberg number Wi and polymer concentration ?. We test quantitively the elastic theory proposed by de Gennes and Tabor (Europhys. Lett., 1986; Physica A, 1986). The rate of energy transfer by polymer elasticity as inferred from the theory is consistent with that measured from the second order Eulerian structure functions. The unknown parameter n in the theory, which represents the flow topology of the stretching field, is found to be nearly 1. Based on energy transfer rate balance, We propose an elastic length scale, r?, which describes the effect of polymer elasticity on turbulence energy cascade and captures the scale dependence of the elastic energy transfer rate. We are grateful to the Max Planck Society, the Alexander von Humboldt Foundation and the Deutsche Forschungsgemeinschaft for their support.
Measurements of radiated elastic wave energy from dynamic tensile cracks
NASA Astrophysics Data System (ADS)
Boler, Frances M.
1990-03-01
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.
Cosmological perturbations in elastic dark energy models
NASA Astrophysics Data System (ADS)
Battye, Richard A.; Moss, Adam
2007-07-01
We discuss the general framework for a perfect continuum medium in cosmology and show that an interesting generalization of the fluids normally used is for the medium to have rigidity and, hence, be analogous to an elastic solid. Such models can provide perfect, adiabatic fluids which are stable even when the pressure is negative, if the rigidity is sufficiently large, making them natural candidates to describe the dark energy. In fact, if the medium is adiabatic and isotropic, they provide the most general description of linearized perturbations. We derive the equations of motion and wave propagation speeds in the isotropic case. We point out that anisotropic models can also be incorporated within the same formalism and that they are classified by the standard Bravais lattices. We identify the adiabatic and isocurvature modes allowed in both the scalar and vector sectors and discuss the predictions they make for cosmic microwave background and matter power spectra. We comment on the relationship between these models and other fluid-based approaches to dark energy, and discuss a possible microphysical manifestation of this class of models as a continuum description of defect-dominated scenarios.
Relativistic optical potential method for elastic electron scattering from heavy noble gases
S.Chen; McEachran, R.P.; Stauffer, A.D. [York Univ., Toronto (Canada)
1996-05-01
A relativistic version of the optical potential method for electron scattering from atoms is derived from the relativistic close-coupling approximation using Dirac-Fock target wave functions. The method is applied to elastic scattering from the heavy noble gases. Differential and total cross sections as well as the STU spin polarization parameters will be presented for xenon when 20 discrete states (open channels) are included in the optical potential. Results and discussion will be presented for incident energies in the range from 25 to 150 eV.
Calculations of {sup 8}He+p elastic cross sections using a microscopic optical potential
Lukyanov, V. K.; Zemlyanaya, E. V.; Lukyanov, K. V.; Kadrev, D. N.; Antonov, A. N.; Gaidarov, M. K.; Massen, S. E.
2009-08-15
An approach to calculate microscopic optical potential with the real part obtained by a folding procedure and with the imaginary part inherent in the high-energy approximation is applied to study the {sup 8}He+p elastic-scattering data at energies of tens of MeV/nucleon. The neutron and proton density distributions obtained in different models for {sup 8}He are used in the calculations of the differential cross sections. The role of the spin-orbit potential is studied. Comparison of the calculations with the available experimental data on the elastic-scattering differential cross sections at beam energies of 15.7, 26.25, 32, 66, and 73 MeV/nucleon is performed. The problem of the ambiguities of the depths of each component of the optical potential is considered by means of the imposed physical criterion related to the known behavior of the volume integrals as functions of the incident energy. It is shown also that the role of the surface absorption is rather important, in particular for the lowest incident energies (e.g., 15.7 and 26.25 MeV/nucleon)
Lateral density variations in elastic Earth models from an extended minimum energy approach
NASA Technical Reports Server (NTRS)
Sanchez, B. V.
1980-01-01
Kaula's minimum energy approach was extended to include the nonhydrostatic gravitational potential energy and the density perturbation field was obtained to degree and order eight. The depth profiles for the density perturbation show a stratification with density excesses and deficiencies alternating with depth. The addition of the gravitational potential energy in the minimization process does not change significantly the conclusions based on results for the minimum shear strain energy case, concerning the inability of the mantle to withstand the lateral loading elastically.
A Microscopic Optical Potential Approach to {sup 6,8}He+p Elastic Scattering
Lukyanov, V. K.; Zemlyanaya, E. V.; Lukyanov, K. V.; Kadrev, D. N.; Antonov, A. N.; Gaidarov, M. K.; Massen, S. E.
2009-08-26
A microscopic approach to calculate the optical potential (OP) with the real part obtained by a folding procedure and with the imaginary part inherent in the high-energy approximation (HEA) is applied to study the {sup 6,8}He+p elastic scattering data at energies of tens of MeV/N. The OP's and the cross sections are calculated using different models for the neutron and proton densities of {sup 6,8}He. The role of the spin-orbit (SO) potential and effects of the energy and density dependence of the effective NN forces are studied. Comparison of the calculations with the available experimental data on the elastic scattering differential cross sections at beam energies <100 MeV/N is performed and conclusions on the role of the aforesaid effects are made. It is shown that the present approach, which uses only parameters that renormalize the depths of the OP, can be applied along with other methods like that from the microscopic g-matrix description of the complex proton optical potential.
Energy in elastic fiber embedded in elastic matrix containing incident SH wave
NASA Technical Reports Server (NTRS)
Williams, James H., Jr.; Nagem, Raymond J.
1989-01-01
A single elastic fiber embedded in an infinite elastic matrix is considered. An incident plane SH wave is assumed in the infinite matrix, and an expression is derived for the total energy in the fiber due to the incident SH wave. A nondimensional form of the fiber energy is plotted as a function of the nondimensional wavenumber of the SH wave. It is shown that the fiber energy attains maximum values at specific values of the wavenumber of the incident wave. The results obtained here are interpreted in the context of phenomena observed in acousto-ultrasonic experiments on fiber reinforced composite materials.
N. A. Elmahdy; A. Y. Ellithi; A. SH. Ghazal; Z. Metawei; M. Y. M. Hassan
2013-12-19
The microscopic eikonal phase shifts with its first and second corrections for pi nucleus collision are calculated by using the expression previously derived for the local Kisslinger potential. A physical description to different forms of targets density distributions, are implemented. The roles of the Ericson Ericson Lorentz Lorentz EELL parameter and the adjustable scattering amplitude parameters are discussed.The calculated differential cross sections include the second order corrections of eikonal phase shift.The need for modifying the effective interaction to account for higher order corrections, larger scattering angles and for lower incident projectile momentum is discussed.The results of this theory for 12C 16O 28Si 40 44 48Ca and 208Pb nuclei are shown to yield satisfactory agreement with experimental data in the momentum range of 114 to 292 MeVc.
NASA Astrophysics Data System (ADS)
Jablonski, A.; Salvat, F.; Powell, C. J.
2004-06-01
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 four energies (100, 500, 1000, and 10 000 eV) from two databases issued by the National Institute of Standards and Technology in which DCSs had been obtained from the TFD and DHF potentials. While the DCSs from the two potentials had similar shapes and magnitudes, there can be pronounced deviations (up to 70%) for small scattering angles for Al, Ag, Au, and Cm. In addition, there were differences of up to 400% at scattering angles for which there were deep minima in the DCSs; at other angles, the differences were typically less than 20%. The DCS differences decreased with increasing electron energy. DCSs calculated from the two potentials were compared with measured DCSs for six atoms (He, Ne, Ar, Kr, Xe, and Hg) at energies between 50 eV and 3 keV. For Ar, the atom for which experimental data are available over the largest energy range there is good agreement between the measured DCSs and those calculated from the TFD and DHF potentials at 2 and 3 keV, but the experimental DCSs agree better with the DCSs from the DHF potential at lower energies. A similar trend is found for the other atoms. At energies less than about 1 keV, there are increasing differences between the measured DCSs and the DCSs calculated from the DHF potential. These differences were attributed to the neglect of absorption and polarizability effects in the calculations. We compare transport cross sections for H, Al, Ni, Ag, Au, and Cm obtained from the DCSs for each potential. For energies between 200 eV and 1 keV, the largest differences are about 20% (for H, Au, and Cm); at higher energies, the differences are smaller. We also examine the extent to which three quantities derived from DCSs vary depending on whether the DCSs were obtained from the TFD or DHF potential. First, we compare calculated and measured elastic-backscattered intensities for thin films of Au on a Ni substrate with different measurement conditions, but it is not clear whether DCSs from the TFD or DHF potential should be preferred. Second, we compare electron inelastic mean free paths (IMFPs) derived from relative and absolute measurements by elastic-peak electron spectroscopy and from analyses with DCSs obtained from the TFD and DHF potentials. In four examples, for a variety of materials and measurement conditions, we find differences between the IMFPs from the TFD and DHF potentials ranging from 1.3% to 17.1%. Third, we compare mean escape depths for two photoelectron lines and two Auger-electron lines in solid Au obtained using DCSs from the TFD and DHF potentials. The relative differences between these mean escape depths vary from 4.3% at 70 eV to0.5% at 2016 eV at normal electron emission, and become smaller with increasing emission angle. Although measured DCSs for atoms can differ from DCSs calculated from the DHF potential by up to a factor of 2, we find that the atomic DCSs are empirically useful for simulations of electron transport in solids for electron energies above about 300 eV. The atomic DCSs can also be useful for energies down to at least 200 eV if relative measurements are made.
Gravitational potential as a source of earthquake energy
Barrows, L.; Langer, C.J.
1981-01-01
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.
High Energy Elastic pp Scattering in Additive Quark Model
Yu. M. Shabelski; A. G. Shuvaev
2014-10-29
High energy $pp$ and $p\\bar p$ elastic scattering is treated in the framework of Additive Quark Model. The reasonable agreement with experimental data is achieved with the natural parameters for the strong matter distribution inside proton.
Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities
-data' based on a series of simulations in which I vary energy and capital input prices over a wide range. I to calculate price- independent changes in energy-efficiency in the form of the AEEI, by comparing energyHybrid Simulation Modeling to Estimate U.S. Energy Elasticities by Adam C. Baylin-Stern B.A. & Sc
Theoretical aspects of high energy elastic nucleon scattering
Vojtech Kundrat; Jan Kaspar; Milos Lokajicek
2009-12-07
The eikonal model must be denoted as strongly preferable for the analysis of elastic high-energy hadron collisions. The given approach allows to derive corresponding impact parameter profiles that characterize important physical features of nucleon collisions, e.g., the range of different forces. The contemporary phenomenological analysis of experimental data is, however, not able to determine these profiles unambiguously, i.e., it cannot give the answer whether the elastic hadron collisions are more central or more peripheral than the inelastic ones. However, in the collisions of mass objects (like protons) the peripheral behavior of elastic collisions should be preferred.
Universal formulae for the limiting elastic energy of membrane networks
Schmidt, Bernd
for the limiting stretching and bending energies of triangulated membrane networks endowed with nearest neighbor of the continuum limit of stretching and bending energies, when the nearest neighbor distance r becomesUniversal formulae for the limiting elastic energy of membrane networks B. Schmidt a,n , F
Kinpara, Susumu
2015-01-01
Bethe-Salpeter equation is applied to nucleon-nucleon elastic scattering at the intermediate energy. The differential cross section and the polarization are calculated in terms of the phase shift analysis method using the two-body potential derived from the Bethe-Salpeter equation. The lowest-order Born approximation for the K-matrix is corrected by including the inverse square part of the potential.
Low-energy elastic electron interactions with pyrimidine
Palihawadana, Prasanga; Sullivan, James; Buckman, Stephen; Brunger, Michael; Winstead, Carl; McKoy, Vincent; Garcia, Gustavo; Blanco, F.
2011-12-15
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.
To the theory of high-energy elastic nucleon collisions
Vojtech Kundrat; Jan Kaspar; Milos Lokajicek
2007-12-10
The commonly used West and Yennie integral formula for the relative phase between the Coulomb and elastic hadronic amplitudes requires for the phase of the elastic hadronic amplitude to be constant at all kinematically allowed values of t. More general interference formula based on the eikonal model approach does not exhibit such limitation. The corresponding differences will be demonstrated and some predictions of different phenomenological models for elastic pp scattering at energy of 14 TeV at the LHC will be given. Special attention will be devoted to determination of luminosity from elastic scattering data; it will be shown that the systematic error might reach till 5 % if the luminosity is derived from the values in the center of the interference region with the help of West and Yennie formula.
Quasi-elastic nuclear scattering at high energies
NASA Technical Reports Server (NTRS)
Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.
1992-01-01
The quasi-elastic scattering of two nuclei is considered in the high-energy optical model. Energy loss and momentum transfer spectra for projectile ions are evaluated in terms of an inelastic multiple-scattering series corresponding to multiple knockout of target nucleons. The leading-order correction to the coherent projectile approximation is evaluated. Calculations are compared with experiments.
Elastic and total cross sections for simple biomolecules in the intermediate energy range
NASA Astrophysics Data System (ADS)
Gupta, Dhanoj; Naghma, Rahla; Antony, Bobby
2015-09-01
The elastic and total cross sections for formaldehyde, acetaldehyde, acetone, 2-butanone and formamide are calculated using the spherical complex optical potential formalism in the intermediate energy range from 50 eV to 10 keV. These cross sections find application to various fields like radiation damage and biological sciences. The present results are compared with the available experimental and theoretical data and are found to give excellent agreement. The elastic cross sections reported for most of the targets in the present energy range are done for the first time. The energy dependence of the contribution of ionization and elastic cross section with respect to the total cross section and the correlation of total cross section with polarizability of the molecules are also studied.
Study of precipitate morphology by consideration of elastic strain energy
Wedge, D.E.
1980-12-01
A formulation given by A.G. Khachaturyan for the elastic strain energy of a coherent second phase inclusion of arbitrary shape in an elastically anisotropic medium is used to calculate numerically the elastic energy for three different shapes - disk, lens, and ellipsoid - of ..cap alpha..'' (Fe/sub 16/N/sub 2/) particles in the Fe-N system, as a function of the particle aspect ratio. The results of the calculation are used to compute values for an isotropic interface energy ..gamma.., using experimental reports of particle dimensions. Two other elastic energy models are also used to compute ..gamma.., one from an analytical approximation by Khachaturyan, and one from the work of J.D. Eshelby. All these models are also used in conjunction with an anisotropic interface energy model to calculate values for the habit plane interface energy ..gamma../sub H/. The vaues for the interface energy are found to be much more consistent with the theory when the anisotropic model is used.
NASA Astrophysics Data System (ADS)
Leng, Y. G.; Gao, Y. J.; Tan, D.; Fan, S. B.; Lai, Z. H.
2015-02-01
To overcome the defect of conventional nonlinear piezoelectric cantilever vibration energy harvesters, in this paper we conceive an elastic-support model to study the performance of energy converters under two types of variable-intensity excitation conditions: filtered Gaussian noises and pink noises. When excitation intensity is insufficient, thanks to the system's variable potential function, frequent bistable transition oscillations between two wells occur in elastic-support systems, while only weak oscillations in either well could be observed in rigid-support systems. In practical applications, the structural parameters of energy harvesters are not allowed to make real-time changes. If considered remaining the magnet interval and the spring's elastic stiffness unchanged while receiving stable maximum output voltage, elastic-support systems can be made full use toward variable-intensity filtered Gaussian noises. It has been proven that elastic-support systems are capable of adapting to random excitations with variable intensity, through which maximum power output and sufficient electromechanical energy conversion of the system can be accomplished.
Do we understand elastic scattering up to LHC energies?
Soffer, Jacques [Physics Department, Temple University, Philadelphia, PA 19122-6082 (United States)
2013-04-15
The measurements of high energy (bar sign)pp and pp elastic at ISR, SPS, and Tevatron colliders have provided usefull informations on the behavior of the scattering amplitude. A large step in energy domain is accomplished with the LHC collider presently running, giving a unique opportunity to improve our knowledge on the asymptotic regime of the elastic scattering amplitude and to verify the validity of our theoretical approach, to describe the total cross section {sigma}{sub tot}(s), the total elastic cross section {sigma}{sub el}(s), the ratio of the real to imaginary parts of the forward amplitude {rho}(s) and the differential cross section d{sigma} (s,t)/dt.
Roubos, D.; Pakou, A.; Alamanos, N.; Rusek, K.
2006-05-15
The radial sensitivity of elastic scattering for weakly bound ({sup 6}Li, {sup 7}Li, {sup 9}Be) and tightly bound projectiles ({sup 12}C, {sup 16}O) on light and heavy targets ({sup 28}Si, {sup 58}Ni, {sup 118}Sn, {sup 208}Pb, {sup 209}Bi) is sought at barrier energies, taking into account a Woods -Saxon potential and a BDM3Y1 interaction. The results are discussed in terms of the potential anomaly at the coulomb barrier.
Multistable Architected Materials for Trapping Elastic Strain Energy.
Shan, Sicong; Kang, Sung H; Raney, Jordan R; Wang, Pai; Fang, Lichen; Candido, Francisco; Lewis, Jennifer A; Bertoldi, Katia
2015-08-01
3D printing and numerical analysis are combined to design a new class of architected materials that contain bistable beam elements and exhibit controlled trapping of elastic energy. The proposed energy-absorbing structures are reusable. Moreover, the mechanism of energy absorption stems solely from the structural geometry of the printed beam elements, and is therefore both material- and loading-rate independent. PMID:26088462
NASA Astrophysics Data System (ADS)
Korff, A.; Haefner, P.; Bäumer, C.; van den Berg, A. M.; Blasi, N.; Davids, B.; de Frenne, D.; de Leo, R.; Frekers, D.; Grewe, E.-W.; Harakeh, M. N.; Hofmann, F.; Hunyadi, M.; Jacobs, E.; Junk, B. C.; Negret, A.; von Neumann-Cosel, P.; Popescu, L.; Rakers, S.; Richter, A.; Wörtche, H. J.
2004-12-01
Angular distributions of differential cross sections for elastic and inelastic deuteron scattering from 6Li , 16O , 32S , 50,51 V , and 70,72 Ge at an incident energy of 171 MeV and from 90Zr and 116Sn at an incident energy of 183 MeV are presented. Phenomenological optical-model parameters for elastic scattering are extracted from the data and compared to existing deuteron-nucleus global optical potentials.
Heller, L.
1985-01-01
It is argued on theoretical and phenomenological grounds that confinement of quarks is intrinsically a many-body interaction. The Born-Oppenheimer approximation to the bag model is shown to give rise to a static potential energy that consists of a sum of two-body Coulomb terms and a many-body confining term. Following the success of this potential in heavy Q anti Q systems it is being applied to Q/sup 2/ anti Q/sup 2/. Preliminary calculations suggest that dimeson bound states with exotic flavor, such as bb anti s anti s, exist. 13 refs., 5 figs.
Continuum limits of atomistic energies allowing smooth and sharp interfaces in 1D Elasticity
Carlos Mora-Corral
2008-08-15
In this paper we present two atomistic models for the energy of a one-dimensional elastic crystal. We assume that the macroscopic displacement equals the microscopic one. The energy of the first model is given by a two-body interaction potential, and we assume that the atoms follow a continuous and piecewise smooth macroscopic (continuum) deformation. We calculate the first terms of the Taylor expansion (with respect to the parameter representing the interatomic distance) of the atomistic energy, and obtain that the coefficients of that Taylor expansion represent, respectively, an elastic energy, a sharp-interface energy, and a smooth-interface energy. The second atomistic model is a variant of the first one, and its Taylor expansion predicts, in addition, a new term that accounts for the repulsion force between two sharp interfaces.
Measurements of radiated elastic wave energy from dynamic tensile cracks
NASA Technical Reports Server (NTRS)
Boler, Frances M.
1990-01-01
The role of fracture-velocity, microstructure, and fracture-energy barriers in elastic wave radiation during a dynamic fracture was investigated in experiments in which dynamic tensile cracks of two fracture cofigurations of double cantilever beam geometry were propagating in glass samples. The first, referred to as primary fracture, consisted of fractures of intact glass specimens; the second configuration, referred to as secondary fracture, consisted of a refracture of primary fracture specimens which were rebonded with an intermittent pattern of adhesive to produce variations in fracture surface energy along the crack path. For primary fracture cases, measurable elastic waves were generated in 31 percent of the 16 fracture events observed; the condition for radiation of measurable waves appears to be a local abrupt change in the fracture path direction, such as occurs when the fracture intersects a surface flaw. For secondary fractures, 100 percent of events showed measurable elastic waves; in these fractures, the ratio of radiated elastic wave energy in the measured component to fracture surface energy was 10 times greater than for primary fracture.
Measurements of radiated elastic wave energy from dynamic tensile cracks
Frances M. Boler
1990-01-01
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
Transient accumulation of elastic energy in proton translocating ATP synthase
Steinhoff, Heinz-Jürgen
Hypothesis Transient accumulation of elastic energy in proton translocating ATP synthase Dmitry A 12 March 1999 Abstract ATP synthase is conceived as a rotatory engine with two reversible drives that the hydrolysis of three molecules of ATP in FI drives the shaft over a full circle in three steps of 120³ each
Neuromechanics of elastic energy storage and recovery during ballistic
Valero-Cuevas, Francisco
Neuromechanics of elastic energy storage and recovery during ballistic movements. Abstract Muscle investigating ballistic prey capture behavior in toads, we re-discovered the usefulness of an old technique of muscles and connective tissues during ballistic movements. The model accurately predicts the observed
Elastic positron-cadmium scattering at low energies
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
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.
Elastic diffractive scattering of nucleons at ultra-high energies
A. A. Godizov
2015-04-08
A simple Regge-eikonal model with the eikonal represented as a single-reggeon-exchange term is applied to description of the nucleon-nucleon elastic diffractive scattering at ultra-high energies. The range of validity of the proposed approximation is discussed. The model predictions for the proton-proton cross-sections at the collision energy 14 TeV are given.
Physics 321 Energy Conservation Potential Energy in
Hart, Gus
Physics 321 Hour 7 Energy Conservation Potential Energy in One Dimension Bottom Line · Energy is conserved. · Kinetic energy is a definite concept. · If we can determine the kinetic energy at all points in space by knowing it at one point in space, we can invent a potential energy so that energy can
Borowska, L.; Terenetsky, K.; Verbitsky, V.; Fritzsche, S.
2009-04-15
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.
B. N. J. Persson
2008-05-06
When two elastic solids with randomly rough surfaces are brought in contact, a very inhomogeneous stress distribution sigma(x) will occur at the interface. Here I study the elastic energy and the correlation function , where sigma(q) is the Fourier transform of sigma(x) and where stands for ensemble average. I relate to the elastic energy stored at the interface, and I show that for self affine fractal surfaces, quite generally \\sim q^{-(1+H)}, where H is the Hurst exponent of the self-affine fractal surface.
Elastic backscattering measurements for {sup 6}Li+{sup 28}Si at sub- and near-barrier energies
Zerva, K.; Patronis, N.; Pakou, A.; Aslanoglou, X.; Nicolis, N. G.; Alamanos, N.; Kokkoris, M.; La Commara, M.; Lagoyannis, A.; Mazzocco, M.; Pierroutsakou, D.; Romoli, M.; Rusek, K.
2009-07-15
Elastic backscattering measurements were performed for the weakly bound nucleus {sup 6}Li on a {sup 28}Si target at sub- and near-barrier energies (0.6 to 1.3 V{sub C.B.}). Excitation functions of elastic scattering cross sections were measured at 150 deg. and 170 deg. and the corresponding ratios to Rutherford scattering and relevant barrier distributions were formed. The results are discussed in terms of the potential threshold anomaly and the reaction mechanisms involved.
Intermediate energy nucleon-deuteron elastic scattering
NASA Technical Reports Server (NTRS)
Wilson, J. W.
1973-01-01
The adequacy of a multiple scattering description of nucleon-deuteron scattering at intermediate energy is examined. Although the multiple-scattering series is expected to converge slowly, model calculations indicate that the higher-order multiple-scattering terms contribute only to the low-order partial waves. The first two terms, nucleon exchange and single scattering, are assumed to describe the high-order partial waves completely. It is assumed that the deuteron is coupled only to the nucleon channel and that the internal structure is adequately defined by a nonrelativistic wave function.
Low-Energy Elastic Electron Scattering by Atomic Oxygen
NASA Technical Reports Server (NTRS)
Zatsarinny O.; Bartschat, K.; Tayal, S. S.
2006-01-01
The B-spline R-matrix method is employed to investigate the low-energy elastic electron scattering by atomic oxygen. Flexible non-orthogonal sets of radial functions are used to construct the target description and to represent the scattering functions. A detailed investigation regarding the dependence of the predicted partial and total cross sections on the scattering model and the accuracy of the target description is presented. The predicted angle-integrated elastic cross sections are in good agreement with experiment, whereas significant discrepancies are found in the angle-differential elastic cross sections near the forward direction. .The near-threshold results are found to strongly depend on the treatment of inner-core short-range correlation effects in the target description, as well as on a proper account of the target polarizability. A sharp increase in the elastic cross sections below 1 eV found in some earlier calculations is judged to be an artifact of an unbalanced description of correlation in the N-electron target structure and the (N+l)-electron-collision problems.
Breakup and Elastic Scattering in the {sup 9}Be + {sup 144}Sm system at near barrier energies
Paes, B.; Garcia, V. N.; Lubian, J.; Gomes, P. R. S.; Padron, I.
2010-05-21
Breakup and elastic scattering in the Be + {sup 144}Sm system, at near barrier energies, are investigated. We calculate theoretically the non-capture breakup cross section by performing coupled reaction channel calculations. The energy dependence of the optical potential does not show the usual threshold anomaly found in tightly bound systems.
Elastic Free Energy Drives the Shape of Prevascular Solid Tumors
Mills, K. L.; Kemkemer, Ralf; Rudraraju, Shiva; Garikipati, Krishna
2014-01-01
It is well established that the mechanical environment influences cell functions in health and disease. Here, we address how the mechanical environment influences tumor growth, in particular, the shape of solid tumors. In an in vitro tumor model, which isolates mechanical interactions between cancer tumor cells and a hydrogel, we find that tumors grow as ellipsoids, resembling the same, oft-reported observation of in vivo tumors. Specifically, an oblate ellipsoidal tumor shape robustly occurs when the tumors grow in hydrogels that are stiffer than the tumors, but when they grow in more compliant hydrogels they remain closer to spherical in shape. Using large scale, nonlinear elasticity computations we show that the oblate ellipsoidal shape minimizes the elastic free energy of the tumor-hydrogel system. Having eliminated a number of other candidate explanations, we hypothesize that minimization of the elastic free energy is the reason for predominance of the experimentally observed ellipsoidal shape. This result may hold significance for explaining the shape progression of early solid tumors in vivo and is an important step in understanding the processes underlying solid tumor growth. PMID:25072702
Quantification of the Potential Energy
Columbia University
(ICE). Energy from waste has an important role to play in improving energy security in the UK and1 waste up to 2020. To determine the potential2 contribution that energy recovery from residual shows that: potential energy recovery from these residual wastes could account for as much as 17
The 106Cd(?, ?)106Cd elastic scattering in a wide energy range for ? process studies
NASA Astrophysics Data System (ADS)
Ornelas, A.; Kiss, G. G.; Mohr, P.; Galaviz, D.; Fülöp, Zs.; Gyürky, Gy.; Máté, Z.; Rauscher, T.; Somorjai, E.; Sonnabend, K.; Zilges, A.
2015-08-01
Alpha elastic scattering angular distributions of the 106Cd(?, ?)106Cd reaction were measured at three energies around the Coulomb barrier to provide a sensitive test for the ? + nucleus optical potential parameter sets. Furthermore, the new high precision angular distributions, together with the data available from the literature were used to study the energy dependence of the locally optimized ? + nucleus optical potential in a wide energy region ranging from ELab = 27.0 MeV down to 16.1 MeV. The potentials under study are a basic prerequisite for the prediction of ?-induced reaction cross sections and thus, for the calculation of stellar reaction rates used for the astrophysical ? process. Therefore, statistical model predictions using as input the optical potentials discussed in the present work are compared to the available 106Cd + alpha cross section data.
The elastic scattering of positrons from beryllium and magnesium in the low-energy region
NASA Astrophysics Data System (ADS)
Bromley, M. W. J.; Mitroy, J.; Ryzhikh, G.
1998-10-01
The elastic scattering of positrons from beryllium and magnesium is studied by using a simple model potential to represent the interaction between the positron and target atoms. The model is tuned by adjusting the free parameters to reproduce previous predictions of the positron binding energies of the 0953-4075/31/19/027/img1 and 0953-4075/31/19/027/img2 ground states. An indication of the theoretical uncertainty in the derived phase shifts and cross sections is given by running a series of calculations with slightly different model potentials. The estimated scattering lengths are 0953-4075/31/19/027/img3 and 0953-4075/31/19/027/img4 for Be and Mg, respectively. The total cross section for positron-magnesium scattering constructed by adding the inelastic cross section computed with many-body perturbation theory to the present elastic cross section is broadly consistent with the experimental data.
Alaska's renewable energy potential.
Not Available
2009-02-01
This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.
NASA Astrophysics Data System (ADS)
Baenas, Tomás; Escapa, Alberto; Ferrándiz, Jose Manuel
2014-05-01
The gravitational action of the Moon and the Sun on the elastic Earth originates a redistribution of its mass. In turn, this redistribution is responsible of an additional term in the gravitational potential energy of the system, commonly referred to as tidal potential of redistribution. Its effects on the Earth rotation were previously discussed in Escapa et al. (2004) and Lambert & Mathews (2006). A numerical approach was followed in those works to show that for an elastic Earth model, assumed to be spherical and non-rotating in the undeformed state, there is no net contribution to the motion of the figure axis. This result is consistent with the corresponding one deduced from the torque approach, where one can derive analytically that the redistribution torque for that elastic Earth model vanishes (e.g., Krasinsky 1999). However, it is far from being a trivial question to recover the same result when working directly with the tidal potential of redistribution, as in Escapa et al. (2004) or Lambert & Mathews (2006). In this investigation we revisit the issue, enhancing and completing former results by Escapa et al. (2004). In particular, we aim at proving, by analytical means, that the redistribution tidal potential of the former elastic Earth model does not affect its rotational motion. To this end we expand that potential in terms of an Andoyer-like set of canonical variables, and then compute the torque associated to it. This choice was motivated by the suitability of this set of variables to extend our calculations to the nutations of other different elastic or anelastic Earth models, through the Hamiltonian framework (e.g., Ferrándiz et al. 2012). We show the exact cancellation of the derived expressions as a consequence of certain properties fulfilled by the expansions of the orbital motion of the perturbing bodies. Acknowledgement. - This work has been partially supported by the Spanish government trhough the MINECO projects I+D+I AYA201022039-C02-01, AYA2010-22039-C02-02, and Universidad de Alicante project GRE11-08. Escapa, A., Getino, J., & Ferrándiz, J. M. 2004, Proc. Journées Sys. Ref., Ed. N. Capitaine, Paris, 70 Ferrándiz, J. M., Baenas, T., & Escapa, A. 2012, Geophys. Res. Abs., 14, EGU2012-6175 Krasinsky, G. A. 1999, Celest. Mech. Dyn. Astron., 75, 39 Lambert, S. & Mathews, P. M. 2006, A&A, 453, 363
Frictional and elastic energy in gecko adhesive detachment.
Gravish, Nick; Wilkinson, Matt; Autumn, Kellar
2008-03-01
Geckos use millions of adhesive setae on their toes to climb vertical surfaces at speeds of over 1 m s(-1). Climbing presents a significant challenge for an adhesive since it requires both strong attachment and easy, rapid removal. Conventional pressure-sensitive adhesives are either strong and difficult to remove (e.g. duct tape) or weak and easy to remove (e.g. sticky notes). We discovered that the energy required to detach adhering tokay gecko setae (W(d)) is modulated by the angle (theta) of a linear path of detachment. Gecko setae resist detachment when dragged towards the animal during detachment (theta = 30 degrees ) requiring W(d) = 5.0+/-0.86(s.e.) J m(-2) to detach, largely due to frictional losses. This external frictional loss is analogous to viscous internal frictional losses during detachment of pressure-sensitive adhesives. We found that, remarkably, setae possess a built-in release mechanism. Setae acted as springs when loaded in tension during attachment and returned elastic energy when detached along the optimal path (theta=130 degrees ), resulting in W(d) = -0.8+/-0.12 J m(-2). The release of elastic energy from the setal shaft probably causes spontaneous release, suggesting that curved shafts may enable easy detachment in natural, and synthetic, gecko adhesives. PMID:17567553
NASA Astrophysics Data System (ADS)
Orazbayev, Azamat
Microscopic optical potentials taking into account the open shell structure of the halo nuclei 6He and 8He are derived and calculated for the first time for the elastic scattering of these nuclei from a polarized proton target. It is demonstrated that the inclusion of open shell effects leads to new terms in the optical potential. Terms associated with the scalar single particle density matrix in spin space are the same as the terms obtained for closed shell nuclei. It is shown that the single particle density matrices corresponding to vectors in spin space vanish in the case of closed shell nuclei. For the open shell nuclei 6He and 8He, the vector in spin space can couple to spin-dependent pieces of the nucleon-nucleon interaction. This leads to additional non-zero terms in the optical potential, which are derived for the first time. In the case of 6He and 8He, one additional central term and one additional spin-orbit term have been identified. The effect of the additional non-zero terms on the differential cross section and analyzing power is found to be small for the scattering energies between 71 and 300 MeV per nucleon. As the projectile kinetic energy increases, the differences between results calculated with the closed shell and modified optical potentials diminish. The nuclei 6He and 8He are described by harmonic oscillator wave functions, and the ground states are assumed to have 1s and 1p shells occupied. The higher levels of harmonic oscillator basis are excluded from consideration. Under this assumption, the harmonic oscillator wave functions do not describe the extended exponential distribution of matter specific to halo nuclei. In order to simulate exponential tails, the harmonic oscillator wave functions are replaced with exponential functions at distances greater than certain matching radii. It is found that exponential tails do not affect the observables at the considered energies. Because there are various estimations for the charge and matter radii of 6He and 8He, the effect of varying the radii is studied. It is established that the scattering observables are sensitive to both the charge and matter radii of the target nucleus. The effect in some cases is significant and can lead to distinctly different results.
Indirect evidence for elastic energy playing a role in limb recovery during toad hopping
Schnyer, Ariela; Gallardo, Mirialys; Cox, Suzanne; Gillis, Gary
2014-01-01
Elastic energy is critical for amplifying muscle power during the propulsive phase of anuran jumping. In this study, we use toads (Bufo marinus) to address whether elastic recoil is also involved after take-off to help flex the limbs before landing. The potential for such spring-like behaviour stems from the unusually flexed configuration of a toad's hindlimbs in a relaxed state. Manual extension of the knee beyond approximately 90° leads to the rapid development of passive tension in the limb as underlying elastic tissues become stretched. We hypothesized that during take-off, the knee regularly extends beyond this, allowing passive recoil to help drive limb flexion in mid-air. To test this, we used high-speed video and electromyography to record hindlimb kinematics and electrical activity in a hindlimb extensor (semimembranosus) and flexor (iliofibularis). We predicted that hops in which the knees extended further during take-off would require less knee flexor recruitment during recovery. Knees extended beyond 90° in over 80% of hops, and longer hops involved greater degrees of knee extension during take-off and more intense semimembranosus activity. However, knee flexion velocities during recovery were maintained despite a significant decrease in iliofibularis intensity in longer hops, results consistent with elastic recoil playing a role. PMID:25030045
Phenomenological optical potential analysis of proton-carbon elastic scattering at 200 MeV
NASA Technical Reports Server (NTRS)
Bidasaria, H. B.; Townsend, L. W.
1982-01-01
Differential cross sections for 200 MeV protons elastically scattered from C-12 were analyzed utilizing a local, complex, spin-dependent optical potential with a harmonic well radial dependence. Analyses were performed using the WKB and eikonal approximations. For the latter, first-order corrections to he phase shifts were incorporated to account for the spin-orbit contribution. Large disagreement between theory and experiment was observed when the usual Thomas form for the spin-orbit potential was utilized. Substantial improvement was obtained by allowing the parameters in the central and spin-orbit potential terms to vary independently.
Potential For Energy Conservation
Kumar, A.
1981-01-01
The largest single area for industrial energy conservation is in the improvement of combustion efficiencies for heaters and boilers. A number of methods can be employed to recover heat. The most common are by use of recuperative air preheaters...
Elastic proton-deuteron scattering at intermediate energies
A. Ramazani-Moghaddam-Arani; Amir-Ahmadi; A. D. Bacher; C. D. Bailey; A. Biegun; M. Eslami-Kalantari; I. Gašpari?; L. Joulaeizadeh; N. Kalantar-Nayestanaki; St. Kistryn; A. Kozela; H. Mardanpour; J. G. Messchendorp; A. M. Micherdzinska; H. Moeini; S. V. Shende; E. Stephan; E. J. Stephenson; R. Sworst
2008-04-19
Observables in elastic proton-deuteron scattering are sensitive probes of the nucleon-nucleon interaction and three-nucleon force effects. The present experimental data base for this reaction is large, but contains a large discrepancy between data sets for the differential cross section taken at 135 MeV/nucleon by two experimental research groups. This paper reviews the background of this problem and presents new data taken at KVI. Differential cross sections and analyzing powers for the $^{2}{\\rm H}(\\vec p,d){p}$ and ${\\rm H}(\\vec d,d){p}$ reactions at 135 MeV/nucleon and 65 MeV/nucleon, respectively, have been measured. The data differ significantly from previous measurements and consistently follow the energy dependence as expected from an interpolation of published data taken over a large range at intermediate energies.
Elastic proton-deuteron scattering at intermediate energies
Ramazani-Moghaddam-Arani, A. [KVI, University of Groningen, Groningen (Netherlands); Department of Physics, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of); Amir-Ahmadi, H. R.; Biegun, A.; Eslami-Kalantari, M.; Joulaeizadeh, L.; Kalantar-Nayestanaki, N.; Mardanpour, H.; Messchendorp, J. G.; Moeini, H.; Shende, S. V. [KVI, University of Groningen, Groningen (Netherlands); Bacher, A. D.; Bailey, C. D.; Stephenson, E. J. [Indiana University Cyclotron Facility, Indiana (United States); Gasparic, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Kistryn, St.; Sworst, R. [Institute of Physics, Jagiellonian University, Cracow (Poland); Kozela, A. [Henryk Niewodniczanski, Institute of Nuclear Physics, Cracow (Poland); Micherdzinska, A. M. [University of Winnipeg, Winnipeg, (Canada); Stephan, E. [Institute of Physics, University of Silesia, Katowice (Poland)
2008-07-15
Observables in elastic proton-deuteron scattering are sensitive probes of the nucleon-nucleon interaction and three-nucleon force effects. The present experimental database for this reaction is large, but contains a large discrepancy between data sets for the differential cross section taken at 135 MeV/nucleon by two experimental research groups. This article reviews the background of this problem and presents new data taken at Kernfysisch Versneller Instituute (KVI). Differential cross sections and analyzing powers for the {sup 2}H(p-vector,d)p and {sup 1}H(d-vector,d)p reactions at 135 MeV/nucleon and 65 MeV/nucleon, respectively, have been measured. The differential cross-section data differ significantly from previous measurements and consistently follow the energy dependence as expected from an interpolation of published data taken over a large range at intermediate energies.
Low-energy elastic electron scattering from furan
Khakoo, M. A.; Muse, J.; Ralphs, K. [Department of Physics, California State University, Fullerton, California 92834 (United States); Costa, R. F. [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, 09210-170 Santo Andre, Sao Paulo (Brazil); Bettega, M. H. F. [Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19044, 81531-990 Curitiba, Parana (Brazil); Lima, M. A. P. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, Caixa Postal 6165, 13083-970 Campinas, Sao Paulo (Brazil); Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6170, 13083-970 Campinas, Sao Paulo (Brazil)
2010-06-15
We report normalized experimental and theoretical differential cross sections for elastic electron scattering by C{sub 4}H{sub 4}O (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 deg. and 130 deg. The measurements verify observed {pi}* 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. A 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 B{sub 1} and A{sub 2} symmetries of the C{sub 2v} 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.
Material selection for elastic energy absorption in origami-inspired compliant corrugations
NASA Astrophysics Data System (ADS)
Tolman, Sean S.; Delimont, Isaac L.; Howell, Larry L.; Fullwood, David T.
2014-09-01
Elastic absorption of kinetic energy and distribution of impact forces are required in many applications. Recent attention to the potential for using origami in engineering may provide new methods for energy absorption and force distribution. A three-stage strategy is presented for selecting materials for such origami-inspired designs that can deform to achieve a desired motion without yielding, absorb elastic strain energy, and be lightweight or cost effective. Two material indices are derived to meet these requirements based on compliant mechanism theory. Finite element analysis is used to investigate the effects of the material stiffness in the Miura-ori tessellation on its energy absorption and force distribution characteristics compared with a triangular wave corrugation. An example is presented of how the method can be used to select a material for a general energy absorption application of the Miura-ori. Whereas the focus of this study is the Miura-ori tessellation, the methods developed can be applied to other tessellated patterns used in energy absorbing or force distribution applications.
NASA Astrophysics Data System (ADS)
Farag, M. Y. H.; Esmael, E. H.; Maridi, H. M.
2012-11-01
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.
NASA Technical Reports Server (NTRS)
Onda, K.; Truhlar, D. G.
1979-01-01
A semiempirical molecular-orbital method for modelling the effective potential for electron-molecule scattering is applied to elastic scattering and rotational excitation of CO2 at 20 eV impact energy. Agreement with experiment is reasonably good. The calculated rotationally summed integral cross section is 67.8 a sub 0 squared.
Magneto-elasticity in hydrogels containing Fe3O4 nanoparticles and their potential applications
NASA Astrophysics Data System (ADS)
Sunaryono, Taufiq, Ahmad; Munaji, Indarto, Bahtera; Triwikantoro, Zainuri, Mochamad; Darminto
2013-09-01
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.
Anchoring energy and orientational elasticity of a ferroelectric liquid crystal
NASA Astrophysics Data System (ADS)
Kaznacheev, A. V.; Pozhidaev, E. P.
2012-06-01
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 ? 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 ? = 41 ?m and evaluate the anchoring energy ( W = 2.8 × 10-3-1.1 × 10-2 J/m2) and the intralayer elastic constant ( K? ? 1 × 10-8-3 × 10-7 N).
Cai, Wei
-direction and is homogeneous in the x- and y-directions. In both bicrystals, the two grains are oriented at Æh=2 about the [001Analysis of the elastic strain energy driving force for grain boundary migration using phase field 2010; accepted 23 July 2010 Available online 29 July 2010 We investigate elastic energy-driven grain
A climbing image nudged elastic band method for finding saddle points and minimum energy paths
Graeme Henkelman; Blas P. Uberuaga; Hannes Jónsson
2000-01-01
A modification of the nudged elastic band method for finding minimum energy paths is presented. One of the images is made to climb up along the elastic band to converge rigorously on the highest saddle point. Also, variable spring constants are used to increase the density of images near the top of the energy barrier to get an improved estimate
NASA Astrophysics Data System (ADS)
Zhang, Yu-Yu; Li, Hao; Wang, Xiao-Ming; Yin, Zheng-Nan; Xiao, Heng
2014-03-01
With a novel approach based on certain logarithmic invariants, we demonstrate that a multi-axial elastic potential for incompressible, isotropic rubber-like materials may be obtained directly from two one-dimensional elastic potentials for uniaxial case and simple shear case, in a sense of exactly matching finite strain data for four benchmark tests, including uniaxial extension, simple shear, bi-axial extension, and plane-strain extension. As such, determination of multi-axial elastic potentials may be reduced to that of two one-dimensional elastic potentials. We further demonstrate that the latter two may be obtained by means of rational interpolating procedures for uniaxial data and shear data displaying strain-stiffening effects. Numerical examples are presented in fitting Treloar's data and other data.
High-energy elastic hadron collisions and space structure of hadrons
Vojtech Kundrat; Milos Lokajicek; D. Krupa
2000-01-06
The elastic and inelastic profiles have been derived from the measured elastic differential cross section data with the help of exact impact parameter representation of elastic scattering amplitude. The results obtained for $pp$ scattering at energy of 53 GeV and $\\bar{p} p$ scattering at energy of 541 GeV have been presented. They indicate that nucleons can be regarded as objects characterized by a small core (diameter $\\sim$ 0.4$\\div$0.8 fm) and a half transparent outer shell (responsible mainly for elastic hadron scattering).
NASA Astrophysics Data System (ADS)
McNeill Alexander, R.
1994-11-01
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.
Tissue elasticity and the ageing elastic fibre.
Sherratt, Michael J
2009-12-01
The ability of elastic tissues to deform under physiological forces and to subsequently release stored energy to drive passive recoil is vital to the function of many dynamic tissues. Within vertebrates, elastic fibres allow arteries and lungs to expand and contract, thus controlling variations in blood pressure and returning the pulmonary system to a resting state. Elastic fibres are composite structures composed of a cross-linked elastin core and an outer layer of fibrillin microfibrils. These two components perform distinct roles; elastin stores energy and drives passive recoil, whilst fibrillin microfibrils direct elastogenesis, mediate cell signalling, maintain tissue homeostasis via TGF? sequestration and potentially act to reinforce the elastic fibre. In many tissues reduced elasticity, as a result of compromised elastic fibre function, becomes increasingly prevalent with age and contributes significantly to the burden of human morbidity and mortality. This review considers how the unique molecular structure, tissue distribution and longevity of elastic fibres pre-disposes these abundant extracellular matrix structures to the accumulation of damage in ageing dermal, pulmonary and vascular tissues. As compromised elasticity is a common feature of ageing dynamic tissues, the development of strategies to prevent, limit or reverse this loss of function will play a key role in reducing age-related morbidity and mortality. PMID:19588272
LHC Physics Potential versus Energy
Quigg, Chris; /Fermilab
2009-08-01
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u{bar d}, and qq interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes.
Strict Relationship: Potential - energy levels
F. Maiz; M. Nasr
2008-12-22
We have developed a new simple method to build the exact analytical expression of the eigenenergy as a function of the potential. The idea of our method is mainly based on the partitioning of the potential curve, solving the Schr\\"odinger equation, realizing a discrete form of the energy quantification condition, and finally, deriving its integral form which permit to create a simple relation: Energy-potential. Our method has been applied to three examples: the well-known square well, the harmonic oscillators, and the Morse potential. Our non numerical method is more realistic, simpler, with high degree of accuracy, both satisfactory and not computationally complicated, and applicable for any forms of potential. Our results agree very well with the preceding ones.
Contribution to the theory of tidal oscillations of an elastic earth. External tidal potential
NASA Technical Reports Server (NTRS)
Musen, P.
1974-01-01
The differential equations of the tidal oscillations of the earth were established under the assumption that the interior of the earth is laterally inhomogeneous. The theory was developed using vectorial and dyadic symbolism to shorten the exposition and to reduce the differential equations to a symmetric form convenient for programming and for numerical integration. The formation of tidal buldges on the surfaces of discontinuity and the changes in the internal density produce small periodic variations in the exterior geopotential which are reflected in the motion of artificial satellites. The analoques of Love elastic parameters in the expansion of exterior tidal potential reflect the asymmetric and inhomogeneous structure of the interior of the earth.
Elastic energy loss and longitudinal straggling of a hard jet
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
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.
Zhou, Songsheng
2012-02-14
.................................................................................................... xii 1. INTRODUCTION ............................................................................................... 1 1.1 Technical Advances and Challenges .................................................... 1 1.2 Review of Existing Studies... .................................................................. 2 1.2.1 Adhesive Contact .................................................................... 2 1.2.2 Surface Elasticity .................................................................... 4 1.2.3 Higher-Order Strain Gradient Theories...
Chapter 20: Electric Potential and Electric Potential Energy
Kioussis, Nicholas
1 Chapter 20: Electric Potential and Electric Potential Energy 2. A 4.5 µC charge moves in a uniform electric field ( )5 ^4.1 10 N/C= ×E x . The change in electric potential energy of a charge moves in a direction perpendicular to the field, the work and change in potential energy are both zero
NASA Astrophysics Data System (ADS)
Ismail, Atef; Lee, Yen Cheong; Tammam, M.
2015-07-01
Proton elastic scattering at various incident energies is one method to study nuclear density distributions and nuclear radii. Single folding potential describing the p-scattering on 40Ca over a broad energy range 9-48.4 MeV is constructed. The resulting potential does not need any renormalization to fit the measured elastic scattering angular distributions and total reaction cross-sections. Furthermore, correlation between volume integral and proton incident energy is discussed. Theoretical calculations are in a good agreement with existing experimental data.
Alpha-particle optical potential proofs at astrophysically relevant energies
M. Avrigeanu; V. Avrigeanu
2008-11-01
$(\\alpha,\\gamma)$ and $(\\alpha$,n) reaction cross sections recently measured close to the reaction thresholds are rather well described by a previously developed regional optical potential. Thus, particular features of the $\\alpha$-particle optical potential at energies below the Coulomb barrier, besides parameters describing $\\alpha$-particle elastic scattering at higher energies are confirmed. Additional limitations of similar statistical model calculations for minor reaction channels are shown to be most likely due to an overlooked process or critical values of statistical model parameters around closed nuclear shells.
Nucleon-deuteron elastic scattering with the Paris nucleon-nucleon potential
Koike, Y.; Haidenbauer, J.; Plessas, W.
1987-02-01
We report on recent advances made in employing realistic nucleon-nucleon forces for nucleon-deuteron elastic scattering. For the first time the Paris potential is used in all relevant partial waves through a separable expansion representing both its on-shell and off-shell properties. Here we present the neutron-deuteron total and differential cross sections below E/sub n/ = 20 MeV as well as the vector-to-vector spin-transfer coefficients of the reaction /sup 2/H(N-arrow-right,d-arrow-right)/sup 1/H at E/sub N/ = 10 MeV. These results may now be regarded as genuine predictions of the Paris potential for these particular observables of nucleon-deuteron scattering.
Examining the Potential of Renewable Energy
Not Available
2006-09-01
This outreach document goes to potential partners for NREL's Renewable Energy Potential Initiative, which will explore the long-term potential of Renewable Energy to meet a substantial share of U.S. energy needs.
Kinetic and Potential Energy of Motion
NSDL National Science Digital Library
Integrated Teaching and Learning Program,
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.
The elastic energy and character of quakes in solid stars and planets
NASA Technical Reports Server (NTRS)
Pines, D.; Shaham, J.
1972-01-01
The quadrupolar mechanical energy of a rotating axially symmetric solid planet (with or without a liquid interior) is calculated using methods previously developed for neutron stars in which an elastic reference tensor is introduced to describe the build-up of elastic energy in the star. The basic parameters of the theory (the gravitational energy A and elastic energy B) depend upon the internal structure of the planet and may be calculated from specific planetary models. Explicit expressions are obtained for the Love numbers, and for the planetary wobble frequency. The theory provides a simple relationship between changes in shape or axis of figure of the planet and elastic energy release. The theory is extended to describe the Earth by taking into account isostasy, triaxiality and the observed lithospheric configuration.
Optical Potential Approach to $K^{+}d$ Scattering at Low Energies
Takashi Takaki
2009-12-15
We study the $K^{+}d$ scattering at low energies using the optical potential. Our optical potential consists of the first-order and second-order terms. The total, integrated elastic and elastic differential cross sections at incident kaon momenta below 800 MeV/c are calculated using our optical potential. We found that our results are consistent with the Faddeev calculation as well as the data and especially the second-order optical potential is essential to reproduce them at low energies. We also discuss the multiple scattering effects in this process.
Renewable energy potential in Colombia
NASA Astrophysics Data System (ADS)
Correa Guzman, Jose Luis
2008-12-01
Renewable energy flows are very large in comparison with humankind's use of energy. In principle, all our energy needs, both now and into the future, can be met by energy from renewable sources. After many years trying to develop the alternative energy potential of Colombia, a major effort is principally being made since 2000 to explore and assess the renewable resources of the entire country. Until 2000, the availability of conventional energy sources in Colombia prevented renewable energy exploration from reaching a higher level. However, the extreme energy crisis of 1992 - 1993 alerted the authorities and the community to the necessity for exploring alternative energy sources. This energy study is a general approach to the current and future renewable energy scenario of Colombia. It was prepared in response to the increased interest around the world and in particular in Colombia to develop its non-fossil energy prospective. It, therefore, represents a working document giving an initial impression of the possible scale of the main renewables sources as a response to the concern about energy security and fossil fuel dependence problems. The assumptions made and calculations reported may therefore be subject to revision as more information becomes available. The aim of this dissertation is not only to improve the public understanding and discussion of renewable energy matters in Colombia but also to stimulate the development and application of renewable energy, wherever they have prospects of economic viability and environmental acceptability. To achieve such goal this paper reviews several renewable technologies, their availability, contribution and feasibility in Colombia.
The Potential of Biogas Energy
MUSTAFA ACAROGLU; GUNNUR KOCAR; ARIF HEPBASLI
2005-01-01
Biogas technology has been known about for a long time, but in recent years the interest in it has significantly increased, especially due to the higher costs and the rapid depletion of fossil fuels as well as their environmental considerations. The main objective of the present study is to investigate the potential of biogas energy in the 15 European Union
Assessment of Triton Potential Energy
J. L. Friar; G. L. Payne
1996-01-26
An assessment is made of the dominant features contributing to the triton potential energy, with the objective of understanding qualitatively their origins and sensitivities. Relativistic effects, short-range repulsion, and OPEP dominance are discussed. A determination of the importance of various regions of nucleon-nucleon separation is made numerically.
Pole structure from energy-dependent and single-energy fits to $?N$ elastic scattering data
Alfred Švarc; Mirza Hadžimehmedovi?; Hedim Osmanovi?; Jugoslav Stahov; Ron L. Workman
2015-01-28
The pole structure of the current GW/SAID partial-wave analysis of elastic $\\pi N$ scattering and $\\eta N$ production data is studied. Pole positions and residues are extracted from both the energy-dependent and single-energy fits, using two different methods. For the energy-dependent fits, both contour integration and a Laurent+Pietarinen approach are used. In the case of single-energy fits, the Laurent+Pietarinen approach is used. Errors are estimated and the two sets of results are compared to other recent and older fits to data.
Nicoli, M. P. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, BP28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, BP28, F-67037 Strasbourg Cedex 2, (France); Haas, F. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, BP28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, BP28, F-67037 Strasbourg Cedex 2, (France); Freeman, R. M. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, BP28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, BP28, F-67037 Strasbourg Cedex 2, (France); Szilner, S.; Basrak, Z. [Ruder Boskovic Institute, Zagreb, (Croatia)] [Ruder Boskovic Institute, Zagreb, (Croatia); Morsad, A. [Faculte des Sciences Ben M'Sik, Universite Hassan II, Casablanca (Morocco)] [Faculte des Sciences Ben M'Sik, Universite Hassan II, Casablanca (Morocco); Satchler, G. R. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States)] [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Brandan, M. E. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Mexico 01000 Distrito Federal, (Mexico)] [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Mexico 01000 Distrito Federal, (Mexico)
2000-03-01
Detailed measurements of the elastic scattering of {sup 16}O ions from {sup 12}C have been carried out at seven energies from 62 to 124 MeV, at center-of-mass angles from about 10 degree sign to about 145 degree sign . A coherent optical model analysis of these data has been performed using both the Woods-Saxon and the folding-model potentials. The extracted results are consistent with analyses of data at higher energies for this and similar light heavy-ion systems. Some model-independent spline forms for the real potentials were also investigated. (c) 2000 The American Physical Society.
Detailed study and mean field interpretation of 16O+12C elastic scattering at seven medium energies
NASA Astrophysics Data System (ADS)
Nicoli, M. P.; Haas, F.; Freeman, R. M.; Szilner, S.; Basrak, Z.; Morsad, A.; Satchler, G. R.; Brandan, M. E.
2000-03-01
Detailed measurements of the elastic scattering of 16O ions from 12C have been carried out at seven energies from 62 to 124 MeV, at center-of-mass angles from about 10° to about 145°. A coherent optical model analysis of these data has been performed using both the Woods-Saxon and the folding-model potentials. The extracted results are consistent with analyses of data at higher energies for this and similar light heavy-ion systems. Some model-independent spline forms for the real potentials were also investigated.
Sun, Qicheng; Jin, Feng; Wang, Guangqian; Song, Shixiong; Zhang, Guohua
2015-01-01
Mesoscopic structures form in dense granular materials due to the self-organisation of the constituent particles. These structures have internal structural degrees of freedom in addition to the translational degree of freedom. The resultant granular elasticity, which exhibits intrinsic variations and inevitable relaxation, is a key quantity that accounts for macroscopic solid- or fluid-like properties and the transitions between them. In this work, we propose a potential energy landscape (PEL) with local stable basins and low elastic energy barriers to analyse the nature of granular elasticity. A function for the elastic energy density is proposed for stable states and is further calibrated with ultrasonic measurements. Fluctuations in the elastic energy due to the evolution of internal structures are proposed to describe a so-called configuration temperature Tc as a counterpart of the classical kinetic granular temperature Tk that is attributed to the translational degrees of freedom. The two granular temperatures are chosen as the state variables, and a fundamental equation is established to develop non-equilibrium thermodynamics for granular materials. Due to the relatively low elastic energy barrier in the PEL, granular elasticity relaxes more under common mechanical loadings, and a simple model based on mean-field theory is developed to account for this behaviour. PMID:25951049
Sun, Qicheng; Jin, Feng; Wang, Guangqian; Song, Shixiong; Zhang, Guohua
2015-01-01
Mesoscopic structures form in dense granular materials due to the self-organisation of the constituent particles. These structures have internal structural degrees of freedom in addition to the translational degree of freedom. The resultant granular elasticity, which exhibits intrinsic variations and inevitable relaxation, is a key quantity that accounts for macroscopic solid- or fluid-like properties and the transitions between them. In this work, we propose a potential energy landscape (PEL) with local stable basins and low elastic energy barriers to analyse the nature of granular elasticity. A function for the elastic energy density is proposed for stable states and is further calibrated with ultrasonic measurements. Fluctuations in the elastic energy due to the evolution of internal structures are proposed to describe a so-called configuration temperature T(c) as a counterpart of the classical kinetic granular temperature T(k) that is attributed to the translational degrees of freedom. The two granular temperatures are chosen as the state variables, and a fundamental equation is established to develop non-equilibrium thermodynamics for granular materials. Due to the relatively low elastic energy barrier in the PEL, granular elasticity relaxes more under common mechanical loadings, and a simple model based on mean-field theory is developed to account for this behaviour. PMID:25951049
Asgari, Meisam
2015-09-01
An expression for the elastic free-energy density of a wormlike micelle is derived taking into account interactions between its constituent molecules. The resulting expression is quadratic in the curvature and torsion of the centerline of micelle and thus resembles free-energy density functions for polymer chains and helical filaments such as DNA. The model is applied on a wormlike micelle in the shape of a circular arc, open or closed. Conditions under which linear chains in dilute systems transform into toroidal rings are analyzed. Two concrete anisotropic soft-core interaction potentials are used to calculate the elastic moduli present in the derived model, in terms of the density of the molecules and their dimensions. Expressions for the persistence length of the wormlike micelle are found based on the flexural rigidities so obtained. Similar to previous observations, our results indicate that the persistence length of a wormlike micelle increases as the aspect ratio of its constituent molecules increases. A detailed application of the model on wormlike micelles of toroidal geometry, along with employing statistical-thermodynamical concepts of self-assembly is performed, and the results are found to be well consistent with the literature. Steps to obtain the material parameters through possible experiments are discussed. PMID:26362658
NASA Astrophysics Data System (ADS)
Kessler, J. A.; Evans, J. P.; Schmitt, D. R.; Shervais, J. W.
2013-12-01
The western Snake River Plain is a region of high crustal heat flow and has the potential for commercial geothermal energy development. High-temperature crystalline reservoirs commonly have connected fracture networks and other discontinuities that provide the primary fluid storage and permeability (Type I fractures). A borehole was drilled during the DOE/ICDP Snake River Scientific Drilling Program near Mountain Home, Idaho to a depth of ~1,800 m (6,000 ft) with 85 - 90% slimhole core recovery to assess the potential for geothermal energy development. A high-temperature artesian flow zone was encountered in basalt at a depth of 1,745 m (5,726 ft) in the MH-2 borehole with fluid temperatures above 140°C (240°F). Analysis of geomechanical behavior of rocks requires an understanding of basic physical and elastic properties under dynamic in-situ stress conditions. Here we conduct unconfined uniaxial compressive stress experiments on core samples to measure static elastic properties and compressive strength over a ~305 m (1,000 ft) interval of the borehole above and including the geothermal reservoir. Acoustic velocities are measured under pressure and temperature scenarios to calculate dynamic elastic properties and describe the anisotropy of elastic moduli and compressive strength. Dynamic elastic properties are calculated from dipole sonic borehole log data and compare the results to the previous dynamic and static interpretations. The comparison demonstrates that the calculation of dynamic elastic properties from borehole data is an effective method to interpret and describe mechanical stratigraphy and elastic properties in the case that core is not available for analysis in this area. Natural fractures, induced fractures, and breakouts are mapped in acoustic televiewer data. Fracture density is calculated and compared to lithological and mechanical stratigraphy, defined by the physical properties, elastic properties, and strength measurements. The stratigraphic relationships indicate that a ~15 m (50 ft) section of weak, non-brittle, low-permeability, highly altered basalt may act as a caprock to the geothermal reservoir at depth. Lithological descriptions of core show that the basalt in MH-2 has been altered and reworked in many cases. The alternating zones of ductile rocks and brittle basalts affect fracture density and can control fracture permeability. The induced fracture and breakout data are used to identify the direction of each of the two horizontal principal stresses. Interpretation of breakout data and induced fracture data indicate that the maximum horizontal principal stress (Shmax) is oriented 50° + 15°. This direction is antithetical to the expected Shmax direction based on the orientation of the normal fault-bounded basin that is oriented approximately 320°.
NASA Astrophysics Data System (ADS)
Milstein, Frederick; Rasky, Daniel J.
1986-02-01
A popular model for metals considers the binding energy Ebind to consist of a structure-dependent part Estr and a volume-dependent part Evol. An analysis of each part's contributions to the pressure, the bulk modulus ?, and the shear moduli ? and ?' reveals combinations of elastic moduli that are evidently fundamental as is evidenced by their systematic variation in the Periodic Table. If ?vol and Pvol are the contributions of Evol to ? and P, respectively, at arbitrary applied pressure P, ?vol-2Pvol=?-2P-?'-(2 /3)?. If nearest-neighbor interactions provide the dominant contributions to the structure-dependent parts of ?, ?, and ?', for fcc crystals, ?vol=?-(1/3)(9?'-10?) and Pvol=2?-?'+P. For aluminum, ?vol/?~=1 (i.e., ?/?'~=0.9) this is considered to be more basic (and is more accurate) than the ``usual'' expression of aluminum's high isotropy (i.e., ?/?'~=1). Similar elastic behavior is predicted for the fcc metals calcium and strontium. For the metals copper, silver, nickel, and lead, ?vol/? is small; i.e., ?~=(1/3)(9?'-10?). Theoretical and empirical considerations suggest the utility of a specific analytical form for Ebind for the noble metals copper, silver, and gold; the form has four model-adjusting constants, the values of which are determined from experimental values of the zero pressure atomic volume and elastic moduli ?, ?, and ?'. The resultant expressions for Ebind are used to compute Pvol, ?vol, theoretical pressure-versus-volume relations, and the first and second pressure derivatives of ?, ?, and ?'. The results compare favorably with experiment and with other (more complex) theoretical computations.
Parton-parton elastic scattering and rapidity gaps at Tevatron energies
Del Duca, V.; Tang, Wai-Keung
1993-08-01
The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at Tevatron energies.
Parton-parton elastic scattering and rapidity gaps at SSC and LHC energies
Duca, V.D.
1993-08-01
The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at SSC and LHC energies.
Elastic and inelastic cross sections for low-energy electron collisions with pyrimidine
NASA Astrophysics Data System (ADS)
Mašín, Zden?k; Gorfinkiel, Jimena D.; Jones, Darryl B.; Bellm, Susan M.; Brunger, Michael J.
2012-04-01
We present theoretical elastic and electronic excitation cross sections and experimental electronic excitation cross sections for electron collisions with pyrimidine. We use the R-matrix method to determine elastic integral and differential cross sections and integral inelastic cross sections for energies up to 15 eV. The experimental inelastic cross sections have been determined in the 15-50 eV impact energy range. Typically, there is quite reasonable agreement between the theoretical and experimental integral inelastic cross sections. Calculated elastic cross sections agree very well with prior results.
California Industrial Energy Efficiency Potential
Coito, Fred; Worrell, Ernst; Price, Lynn; Masanet, Eric; RafaelFriedmann; Rufo, Mike
2005-06-01
This paper presents an overview of the modeling approach andhighlights key findings of a California industrial energy efficiencypotential study. In addition to providing estimates of technical andeconomic potential, the study examines achievable program potential undervarious program-funding scenarios. The focus is on electricity andnatural gas savings for manufacturing in the service territories ofCalifornia's investor-owned utilities (IOUs). The assessment is conductedby industry type and by end use. Both crosscutting technologies andindustry-specific process measures are examined. Measure penetration intothe marketplace is modeled as a function of customer awareness, measurecost effectiveness, and perceived market barriers. Data for the studycomes from a variety of sources, including: utility billing records, theEnergy Information Association (EIA) Manufacturing Energy ConsumptionSurvey (MECS), state-sponsored avoided cost studies, energy efficiencyprogram filings, and technology savings and cost data developed throughLawrence Berkeley National Laboratory (LBNL). The study identifies 1,706GWh and 47 Mth (million therms) per year of achievable potential over thenext twelve years under recent levels of program expenditures, accountingfor 5.2 percent of industrial electricity consumption and 1.3 percent ofindustrial natural gas consumption. These estimates grow to 2,748 GWh and192 Mth per year if all cost-effective and achievable opportunities arepursued. Key industrial electricity end uses, in terms of energy savingspotential, include compressed air and pumping systems that combine toaccount for about half of the total achievable potential estimates. Fornatural gas, savings are concentrated in the boiler and process heatingend uses, accounting for over 99 percent to total achievablepotential.
Elastic and inelastic breakup of deuterons with energy below 100 MeV
Carlson, B V; Sin, M
2015-01-01
We present calculations of deuteron elastic and inelastic breakup cross sections and angular distributions at deuteron energies below 100 MeV obtained using the post-form DWBA approximation. The elastic breakup cross section was extensively studied in the past. Very few calculations of inelastic breakup have been performed, however. We also analyze the angular momentum - energy distributions of the cross section for formation of the compound nucleus after inelastic breakup.
New measurements and phase analysis of the p16O elastic scattering at astrophysical energies
Sergey Dubovichenko; Nasurlla Burtebaev; Albert Dzhazairov-Kakhramanov; Denis Zazulin; Zhambyl Kerimkulov; Maulen Nassurlla; Chingis Omarov; Alesya Tkachenko; Tatyana Shmygaleva; Stanislaw Kliczewski; Turlan Sadykov
2015-08-15
The results of new experimental measurements of the p16O elastic scattering in the energy range of 0.6-1.0 MeV at angles 40-160 deg. are given. Phase shift analysis of the p16O elastic scattering was made using these and other experimental data on differential cross sections in excitation functions and angular distributions at energies up to 2.5 MeV.
New measurements and phase analysis of the p16O elastic scattering at astrophysical energies
Dubovichenko, Sergey; Dzhazairov-Kakhramanov, Albert; Zazulin, Denis; Kerimkulov, Zhambyl; Nassurlla, Maulen; Omarov, Chingis; Tkachenko, Alesya; Shmygaleva, Tatyana; Kliczewski, Stanislaw; Sadykov, Turlan
2015-01-01
The results of new experimental measurements of the p16O elastic scattering in the energy range of 0.6-1.0 MeV at angles 40-160 deg. are given. Phase shift analysis of the p16O elastic scattering was made using these and other experimental data on differential cross sections in excitation functions and angular distributions at energies up to 2.5 MeV.
Eng, Carolyn M; Arnold, Allison S; Biewener, Andrew A; Lieberman, Daniel E
2015-08-01
This study examines whether the human iliotibial band (ITB) is specialized for elastic energy storage relative to the chimpanzee fascia lata (FL). To quantify the energy storage potential of these structures, we created computer models of human and chimpanzee lower limbs based on detailed anatomical dissections. We characterized the geometry and force-length properties of the FL, tensor fascia lata (TFL) and gluteus maximus (GMax) in four chimpanzee cadavers based on measurements of muscle architecture and moment arms about the hip and knee. We used the chimp model to estimate the forces and corresponding strains in the chimp FL during bipedal walking, and compared these data with analogous estimates from a model of the human ITB, accounting for differences in body mass and lower extremity posture. We estimate that the human ITB stores 15- to 20-times more elastic energy per unit body mass and stride than the chimp FL during bipedal walking. Because chimps walk with persistent hip flexion, the TFL and portions of GMax that insert on the FL undergo smaller excursions (origin to insertion) than muscles that insert on the human ITB. Also, because a smaller fraction of GMax inserts on the chimp FL than on the human ITB, and thus its mass-normalized physiological cross-sectional area is about three times less in chimps, the chimp FL probably transmits smaller muscle forces. These data provide new evidence that the human ITB is anatomically derived compared with the chimp FL and potentially contributes to locomotor economy during bipedal locomotion. PMID:26026035
Nucleation rate of critical droplets on an elastic string in a {phi}{sup 6} potential
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
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.
NASA Astrophysics Data System (ADS)
Lukyanov, V. K.; Zemlyanaya, E. V.; Lukyanov, K. V.; Ellithi, A. Y.; Abdul-Magead, I. A. M.
2015-05-01
The pion-nucleus microscopic optical potential (OP), defined by the pion-nucleon scattering amplitude and by the generalized density distribution of a target nucleus that incudes internal degrees of freedom, is applied to construct the pion-nucleus differential cross-sections of elastic and inelastic scattering on the nuclei 28Si, 58Ni, 208Pb at Tlab = 291 MeV. Calculations are based on the relativistic wave equation and thus relativistic effects and distortions on the relative motion wave functions are taken into account. The respective experimental data are analyzed and the in-medium parameters of the elementary ?N-amplitude are established and compared with those from the pion scattering on free nucleons.
An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel
Stanford University
An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel been used to convert wind flow energy into mechanical vibration, which is then transformed-scale renewable energy generating systems such as wind turbines, thermal generators, and solar panels, energy
Elastic and inelastic scattering of electrons reflected from solids: Effects on energy spectra
Tofterup, A.L.
1985-09-01
The effects of elastic and inelastic scattering on energy spectra of electrons reflected from solids have been investigated theoretically. The aim was to evaluate the spectrum in the vicinity of the elastic peak. Following Tougaard and Sigmund's approach (Phys. Rev. B 25, 4452 (1982)), the elastic and inelastic scattering events are separated as independent when calculating the flux of reflected electrons. The influence of elastic scattering is considered here in detail within the P/sub 1/ approximation of the Boltzmann transport equation, and the inelastic scattering is described by the Landau formula. A general expression for the energy spectrum as well as expressions for discrete and continuous energy spectra are derived. Comparisons are made with the continuous part of measured spectra and a reasonable agreement is seen.
Elastic and inelastic scattering of electrons reflected from solids: Effects on energy spectra
NASA Astrophysics Data System (ADS)
Tofterup, Arne L.
1985-09-01
The effects of elastic and inelastic scattering on energy spectra of electrons reflected from solids have been investigated theoretically. The aim was to evaluate the spectrum in the vicinity of the elastic peak. Following Tougaard and Sigmund's approach [Phys. Rev. B 25, 4452 (1982)], the elastic and inelastic scattering events are separated as independent when calculating the flux of reflected electrons. The influence of elastic scattering is considered here in detail within the P1 approximation of the Boltzmann transport equation, and the inelastic scattering is described by the Landau formula. A general expression for the energy spectrum as well as expressions for discrete and continuous energy spectra are derived. Comparisons are made with the continuous part of measured spectra and a reasonable agreement is seen.
The 106Cd(alpha,alpha)106Cd elastic scattering in a wide energy range for gamma-process studies
A. Ornelas; G. G. Kiss; P. Mohr; D. Galaviz; Zs. Fülöp; Gy. Gyürky; Z. Máté; T. Rauscher; E. Somorjai; K. Sonnabend; A. Zilges
2015-04-29
Alpha elastic scattering angular distributions of the 106Cd(alpha,alpha)106Cd reaction were measured at three energies around the Coulomb barrier to provide a sensitive test for the alpha + nucleus optical potential parameter sets. Furthermore, the new high precision angular distributions, together with the data available from the literature were used to study the energy dependence of the locally optimized {\\alpha}+nucleus optical potential in a wide energy region ranging from E_Lab = 27.0 MeV down to 16.1 MeV. The potentials under study are a basic prerequisite for the prediction of alpha-induced reaction cross sections and thus, for the calculation of stellar reaction rates used for the astrophysical gamma process. Therefore, statistical model predictions using as input the optical potentials discussed in the present work are compared to the available 106Cd + alpha cross section data.
Phase-shift analysis of low-energy $?^{\\pm}p$ elastic-scattering data
E. Matsinos; W. S. Woolcock; G. C. Oades; G. Rasche; A. Gashi
2006-07-25
Using electromagnetic corrections previously calculated by means of a potential model, we have made a phase-shift analysis of the $\\pi^\\pm p$ elastic-scattering data up to a pion laboratory kinetic energy of 100 MeV. The hadronic interaction was assumed to be isospin invariant. We found that it was possible to obtain self-consistent databases by removing very few measurements. A pion-nucleon model was fitted to the elastic-scattering database obtained after the removal of the outliers. The model-parameter values showed an impressive stability when the database was subjected to different criteria for the rejection of experiments. Our result for the pseudovector $\\pi N N$ coupling constant (in the standard form) is $0.0733 \\pm 0.0014$. The six hadronic phase shifts up to 100 MeV are given in tabulated form. We also give the values of the s-wave scattering lengths and the p-wave scattering volumes. Big differences in the s-wave part of the interaction were observed when comparing our hadronic phase shifts with those of the current GWU solution. We demonstrate that the hadronic phase shifts obtained from the analysis of the elastic-scattering data cannot reproduce the measurements of the $\\pi^- p$ charge-exchange reaction, thus corroborating past evidence that the hadronic interaction violates isospin invariance. Assuming the validity of the result obtained within the framework of chiral perturbation theory, that the mass difference between the $u$- and the $d$-quark has only a very small effect on the isospin invariance of the purely hadronic interaction, the isospin-invariance violation revealed by the data must arise from the fact that we are dealing with a hadronic interaction which still contains residual effects of electromagnetic origin.
Bolaños, Jorge A.; Longstreth, David J.
1984-01-01
Pressure volume curves for Alternanthera philoxeroides (Mart.) Griseb. (alligator weed) grown in 0 to 400 millimolar NaCl were used to determine water potential (?), osmotic potential (?s), turgor potential (?p) and the bulk elastic modulus (?) of shoots at different tissue water contents. Values of ?s decreased with increasing salinity and tissue ? was always lower than rhizosphere ?. The relationship between ?p and tissue water content changed because ? increased with salinity. As a result, salt-stressed plants had larger ranges of positive turgor but smaller ranges of tissue water content over which ?p was positive. To our knowledge, this is the first report of such a salinity effect on ? in higher plants. These increases in ? with salinity provided a mechanism by which a large difference between plant ? and rhizosphere ?, the driving force for water uptake, could be produced with relatively little water loss by the plant. A time-course study of response after salinization to 400 millimolar NaCl showed ? was constant within 1 day, ?s and ?p continued to change for 2 to 4 days, and ? continued to change for 4 to 12 days. Changes in ? modified the capacity of alligator weed to maintain a positive water balance and consideration of such changes in other species of higher plants should improve our understanding of salt stress. PMID:16663611
Bolaños, J A; Longstreth, D J
1984-06-01
Pressure volume curves for Alternanthera philoxeroides (Mart.) Griseb. (alligator weed) grown in 0 to 400 millimolar NaCl were used to determine water potential (Psi), osmotic potential (psi(s)), turgor potential (psi(p)) and the bulk elastic modulus (epsilon) of shoots at different tissue water contents. Values of psi(s) decreased with increasing salinity and tissue Psi was always lower than rhizosphere Psi. The relationship between psi(p) and tissue water content changed because epsilon increased with salinity. As a result, salt-stressed plants had larger ranges of positive turgor but smaller ranges of tissue water content over which psi(p) was positive. To our knowledge, this is the first report of such a salinity effect on epsilon in higher plants. These increases in epsilon with salinity provided a mechanism by which a large difference between plant Psi and rhizosphere Psi, the driving force for water uptake, could be produced with relatively little water loss by the plant. A time-course study of response after salinization to 400 millimolar NaCl showed Psi was constant within 1 day, psi(s) and psi(p) continued to change for 2 to 4 days, and epsilon continued to change for 4 to 12 days. Changes in epsilon modified the capacity of alligator weed to maintain a positive water balance and consideration of such changes in other species of higher plants should improve our understanding of salt stress. PMID:16663611
Elastic energy of a deformable earth: General expression
Juan Getino; Facultad Ciencias
1992-01-01
This work is the first in the second part of a project dedicated to elaborating a Hamiltonian theory for the rotational motion of a deformable Earth. In the four works which make up the first part the basis of this theory is laid down, studying the effects produced when the Earth's elastic mantle is deformed by lunisolar attraction. More specifically,
Variation of the energy release rate as a crack approaches and passes through an elastic inclusion
NASA Astrophysics Data System (ADS)
Li, Rongshun; Chudnovsky, A.
1993-02-01
The variation of the energy release rate (ERP) at the tip of a crack penetrating an elastic inclusion is analyzed using an approach involving modeling the random array of microcracks or other defects by an elastic inclusion with effective elastic properties. Computations are carried out using a finite element procedure. The eight-noded isoparametric serendipity element with the shift of the midpoint to the quarter-point is used to simulate the singularity at the crack tip, and the crack growth is accommodated by implementing a mesh regeneration technique. The ERP values were calculated for various crack tip positions which simulate the process of the crack approaching and penetrating the inclusion.
Complex angular momentum analysis of low-energy electron elastic scattering from lanthanide atoms
NASA Astrophysics Data System (ADS)
Felfli, Z.; Msezane, A. Z.; Sokolovski, D.
2010-04-01
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-, Tb-, Dy-, Ho-, Er-, and Tm- 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.
Complex angular momentum analysis of low-energy electron elastic scattering from lanthanide atoms
Felfli, Z.; Msezane, A. Z.; Sokolovski, D.
2010-04-15
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.
Improved potential energy surfaces for the interaction of H2 with Ar, Kr, and Xe
Robert J. Le Roy; Jeremy M. Hutson
1987-01-01
A combined analysis of discrete infrared and microwave spectra, elastic and inelastic differential cross section measurements, and virial coefficient data has been used to determine improved potential energy surfaces for the H2–Ar, –Kr, and –Xe systems. Key improvements over previous surfaces for these species are an improved delineation of the diatom bond length dependence of the potential anisotropy, and the
Low-energy nuclear reactions and the alpha-nucleus optical potential: where do we stand?
NASA Astrophysics Data System (ADS)
Demetriou, P.; Axiotis, M.
2007-02-01
Recent efforts to develop an accurate and reliable ?-nucleus optical potential at low energies are presented. In view of the advent of new data on ? elastic scattering and ? radiative-capture reactions, the global semi-microscopic ?-nucleus potential is revisited and compared with the updated database. Needs for improvements are discussed.
Regulation of residual stress in elastic solid component with high-energy acoustic field
NASA Astrophysics Data System (ADS)
Song, W. T.; Xu, C. G.; Pan, Q. X.; Yang, X. C.; Xu, L.; Guo, J.
2013-01-01
The ultrasonic regulation of internal residual stress in metal and nonmetal elastic solid component has been investigated. High-energy ultrasonic wave is applied to carbon steel and ordinary flat glass for residual stress control. An ultrasonic residual stress measurement device developed with the acoustoelastic theory is used to measure macro residual stress in time, to evaluate the residual stress regulation effectiveness. Based on the essence of residual stress, the interaction between acoustic wave and residual stress is analyzed, and dislocations theory is considered. When the ultrasonic energy supplied to the elastic solid is greater than the energy of dislocation, the internal residual stress will be released. Experiments result shows that as high energy acoustic field is applied, the local residual tensile stress in elastic solid specimen will shift gradually to beneficial compressive stress, thus the component's fatigue strength, corrosion resistance and service life will be greatly improved.
Theoretical modeling for neutron elastic scattering angular distribution in the fast energy range
Kawano, Toshihiko
2010-12-07
One of the major issues of neutron scattering modeling in the fast energy range is the contribution of compound elastic and inelastic scattering to the total scattering process. The compound component may become large at very low energies where the angular distribution becomes 90-degree symmetric in the center-of-mass system. Together with the shape elastic component, the elastic scattering gives slightly forward-peaked angular distributions in the fast energy range. This anisotropic angular distribution gives high sensitivities to many important nuclear reactor characteristics, such as criticality and neutron shielding. In this talk we describe how the anisotropic angular distributions are calculated within the statistical model framework, including the case where strongly coupled channels exist, by combining the coupled-channels theory with the Hauser-Feshbach model. This unique capability extension will have significant advantages in understanding the neutron scattering process for deformed nuclei, like uranium or plutonium, on which advanced nuclear energy applications center.
Study of the Elastic Scattering of 32S by 24Mg at Low Energies
NASA Astrophysics Data System (ADS)
Hassanain, Mahmoud A.; Ibraheem, Awad A.
2015-09-01
The elastic scattering angular distribution of 32S on 24Mg at energies ranging from 65 to 110 MeV has been analyzed in the framework of the double folding (DF) model, using different effective nucleon-nucleon (NN) interactions based on the M3Y-Reid interaction. The Pauli correlation, zero-range, and finite-range exchange parts of the NN interactions are considered in the folding procedure to treat the single nucleon knock-on exchange term (SNKE) in the optical model. Successful reproduction of the data has been obtained with all the potentials considered in the present study. It is clear that the effect of Pauli correlation increases as the energy increases. Our calculations are insensitive to the strength of the imaginary potential used in the fit of the experimental data. We find also that the threshold anomaly is less pronounced in the 32S + 24Mg system. Our reaction cross sections are compared with the data, and the consistency between the real and imaginary volume integrals are checked by the dispersion relation.
Spectral Modeling of Residual Stress and Stored Elastic Strain Energy in Thermal Barrier Coatings
Donegan, Sean; Rolett, Anthony
2013-12-31
Solutions to the thermoelastic problem are important for characterizing the response under temperature change of refractory systems. This work extends a spectral fast Fourier transform (FFT) technique to analyze the thermoelastic behavior of thermal barrier coatings (TBCs), with the intent of probing the local origins of failure in TBCs. The thermoelastic FFT (teFFT) approach allows for the characterization of local thermal residual stress and strain fields, which constitute the origins of failure in TBC systems. A technique based on statistical extreme value theory known as peaks-over-threshold (POT) is developed to quantify the extreme values ("hot spots") of stored elastic strain energy (i.e., elastic energy density, or EED). The resolution dependence of the teFFT method is assessed through a sensitivity study of the extreme values in EED. The sensitivity study is performed both for the local (point-by-point) #12;eld distributions as well as the grain scale #12;eld distributions. A convergence behavior to a particular distribution shape is demonstrated for the local #12;elds. The grain scale fields are shown to exhibit a possible convergence to a maximum level of EED. To apply the teFFT method to TBC systems, 3D synthetic microstructures are created to approximate actual TBC microstructures. The morphology of the grains in each constituent layer as well as the texture is controlled. A variety of TBC materials, including industry standard materials and potential future materials, are analyzed using the teFFT. The resulting hot spots are quantified using the POT approach. A correlation between hot spots in EED and interface rumpling between constituent layers is demonstrated, particularly for the interface between the bond coat (BC) and the thermally grown oxide (TGO) layer.
Certifying the Potential Energy Landscape
Dhagash Mehta; Jonathan D. Hauenstein; David J. Wales
2013-02-25
It is highly desirable for a numerical approximation of a stationary point for a potential energy landscape to lie in the quadratic convergence basin of that stationary point. However, it is possible that an approximation may lie only in the linear convergence basin, or even in a chaotic region, and hence not converge to the actual stationary point when further optimization is attempted. Proving that a numerical approximation will quadratically converge to the associated stationary point is termed certifying the numerical approximation. We employ Smale's \\alpha-theory to stationary points, providing a certification that serves as a mathematical proof that the numerical approximation does indeed correspond to an actual stationary point, independent of the precision employed. As a practical example, employing recently developed certification algorithms, we show how the \\alpha-theory can be used to certify all the known minima and transition states of Lennard-Jones LJ$_{N}$ atomic clusters for N = 7, ...,14.
Energy dissipation associated with crack extension in an elastic-plastic material
NASA Technical Reports Server (NTRS)
Shivakumar, K. N.; Crews, J. H., Jr.
1987-01-01
Crack extension in elastic-plastic material involves energy dissipation through the creation of new crack surfaces and additional yielding around the crack front. An analytical procedure, using a two-dimensional elastic-plastic finite element method, was developed to calculate the energy dissipation components during a quasi-static crack extension. The fracture of an isotropic compact specimen was numerically simulated using the critical crack-tip-opening-displacement (CTOD) growth criterion. Two specimen sizes were analyzed for three values of critical CTOD. Results from the analyses showed that the total energy dissipation rate consisted of three components: the crack separation energy rate, the plastic energy dissipation rate, and the residual strain energy rate. All three energy dissipation components and the total energy dissipation rate initially increased with crack extension and finally reached constant values.
Ni, Yilu; Tang, Zhurong; Cao, Wanxu; Lin, Hai; Fan, Yujiang; Guo, Likun; Zhang, Xingdong
2015-03-01
Natural polysaccharides are extensively investigated as cell scaffold materials for cellular adhesion, proliferation, and differentiation due to their excellent biocompatibility, biodegradability, and biofunctions. However, their application is often severely limited by their mechanical behavior. In this study, a tough and elastic hydrogel scaffold was prepared with hyaluronic acid (HA) and chondroitin sulfate (CS). HA and CS were conjugated with tyramine (TA) and the degree of substitution (DS) was 10.7% and 11.3%, respectively, as calculated by (1)H NMR spectra. The hydrogel was prepared by mixing HA-TA and CS-TA in presence of H2O2 and HRP. The sectional morphology of hydrogels was observed by SEM, static and dynamic mechanical properties were analyzed by Shimadzu electromechanical testing machine and dynamic mechanical thermal analyzer Q800. All samples showed good ability to recover their appearances after deformation, the storage modulus (E') of hydrogels became higher as the testing frequency went up. Hydrogels also showed fatigue resistance to cyclic compression. Mesenchymal stem cells encapsulated in hydrogels showed good cell viability as detected by CLSM. This study suggests that the hydrogels have both good mechanical properties and biocompatibility, and may serve as model systems to explore mechanisms of deformation and energy dissipation or find some applications in tissue engineering. PMID:25445680
Nonlinear Elastic Effects on the Energy Flux Deviation of Ultrasonic Waves in GR/EP Composites
NASA Technical Reports Server (NTRS)
Prosser, William H.; Kriz, R. D.; Fitting, Dale W.
1992-01-01
In isotropic materials, the direction of the energy flux (energy per unit time per unit area) of an ultrasonic plane wave is always along the same direction as the normal to the wave front. In anisotropic materials, however, this is true only along symmetry directions. Along other directions, the energy flux of the wave deviates from the intended direction of propagation. This phenomenon is known as energy flux deviation and is illustrated. The direction of the energy flux is dependent on the elastic coefficients of the material. This effect has been demonstrated in many anisotropic crystalline materials. In transparent quartz crystals, Schlieren photographs have been obtained which allow visualization of the ultrasonic waves and the energy flux deviation. The energy flux deviation in graphite/epoxy (gr/ep) composite materials can be quite large because of their high anisotropy. The flux deviation angle has been calculated for unidirectional gr/ep composites as a function of both fiber orientation and fiber volume content. Experimental measurements have also been made in unidirectional composites. It has been further demonstrated that changes in composite materials which alter the elastic properties such as moisture absorption by the matrix or fiber degradation, can be detected nondestructively by measurements of the energy flux shift. In this research, the effects of nonlinear elasticity on energy flux deviation in unidirectional gr/ep composites were studied. Because of elastic nonlinearity, the angle of the energy flux deviation was shown to be a function of applied stress. This shift in flux deviation was modeled using acoustoelastic theory and the previously measured second and third order elastic stiffness coefficients for T300/5208 gr/ep. Two conditions of applied uniaxial stress were considered. In the first case, the direction of applied uniaxial stress was along the fiber axis (x3) while in the second case it was perpendicular to the fiber axis along the laminate stacking direction (x1).
H-He elastic scattering at low energies: Contribution of nonzero partial waves
Sinha, Prabal K.; Ghosh, A.S. [Department of Physics, Bangabasi College, 19, Raj Kumar Chakravorty Sarani, Kolkata 700 009 (India); Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032 (India)
2005-01-01
The present study reports the nonzero partial wave elastic cross sections together with s-wave results for the scattering of an antihydrogen atom off a gaseous helium target at thermal energies (up to 10{sup -2} a.u.). We have used a nonadiabatic atomic orbital method having different basis sets to investigate the system. The consideration of all the significant partial waves (up to J=24) reduces the oscillatory nature present in the individual partial wave cross section. The added elastic cross section is almost constant up to 10{sup -7} a.u. and then decreases steadily and very slowly with increasing energy.
Microscopic positive-energy potential based on the Gogny interaction
NASA Astrophysics Data System (ADS)
Blanchon, G.; Dupuis, M.; Arellano, H. F.; Vinh Mau, N.
2015-01-01
We present a nucleon elastic scattering calculation based on Green's function formalism in the random-phase approximation. For the first time, the finite-range Gogny effective interaction is used consistently throughout the whole calculation to account for the complex, nonlocal, and energy-dependent optical potential. Effects of intermediate single-particle resonances are included and found to play a crucial role in the account for measured reaction cross sections. Double counting of the particle-hole second-order contribution is carefully addressed. The resulting integro-differential Schrödinger equation for the scattering process is solved without localization procedures. The method is applied to neutron and proton elastic scattering from 40Ca. A successful account for differential and integral cross sections, including analyzing powers, is obtained for incident energies up to 30 MeV. Discrepancies at higher energies are related to a much-too-high volume integral of the real potential for large partial waves. This work opens the way to simultaneously assess effective interactions suitable for both nuclear structure and reactions.
Potential of geothermal energy in China
Sung, Peter On
2010-01-01
This thesis provides an overview of geothermal power generation and the potential for geothermal energy utilization in China. Geothermal energy is thermal energy stored in the earth's crust and currently the only ubiquitously ...
Elastic Scattering Of {sup 6,7}Li+{sup 80}Se At Near And Above Barrier Energies
Fimiani, L.; Marti, G. V.; Capurro, O. A.; Barbara, E. de; Testoni, J. E.; Zalazar, L.; Arazi, A.; Cardona, M. A.; Carnelli, P.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Fernandez Niello, J. O.
2010-08-04
In this work we propose to study the elastic scattering of the weakly bound projectiles {sup 6,7}Li on an intermediate mass target {sup 80}Se. From the experimental results presented here, precise angular distributions at energies below, around and above the nominal Coulomb barriers of the systems were obtained. The final goal of our work is to determine the characteristic parameters of the optical potential and use them to address the question of whether the usual threshold anomaly or the breakup threshold anomaly are present or not in these systems.
High energy proton-proton elastic scattering at the Large Hadron Collider and nucleon structure
NASA Astrophysics Data System (ADS)
Luddy, Richard Joseph
To gain insight into the structure of the nucleon, we pursue the development of the phenomenological model of Islam et al. (IIFS model) for high energy elastic pp and p¯p scattering. We determine the energy dependence of the parameters of the IIFS model using the available elastic differential cross section data from SPS Collider and Tevatron and the known asymptotic behavior of sigmatot (s) and rho(s) from dispersion relation calculations and more recent analyses of Cudell et al. (COMPETE Collaboration). Next, we incorporate a high energy elastic valence quark-quark scattering amplitude into the model based on BFKL pomeron to describe small impact parameter (large | t|) pp collisions. Finally, we predict the pp elastic differential cross section at the unprecedented c.m. energy of s = 14.0 TeV at the Large Hadron Collider (LHC). This prediction assumes crucial significance---because of an approved experiment at LHC: TOTal and Elastic Measurement (TOTEM). The TOTEM group plans to measure pp elastic dsigma/dt at 14.0 TeV all the way from momentum transfer |t| = 0 to |t| ? 10 GeV 2. Their measurement will stringently test not only the diffraction and o-exchange descriptions of the original IIFS model, but also the additional valence quark-quark scattering contribution that we find to be dominant for large |t|. Successful quantitative verification of the predicted dsigma/dt will mean that our picture of the nucleon with an outer cloud of qq¯ condensed ground state, an inner core of topological baryonic charge, and a still smaller core of massless valence quarks provides a realistic description of nucleon structure.
Energy current imaging method for time reversal in elastic media
Anderson, Brian E [Los Alamos National Laboratory; Ulrich, Timothy J [Los Alamos National Laboratory; Le Bas, Pierre - Yves A [Los Alamos National Laboratory; Larmat, Carene [Los Alamos National Laboratory; Johnson, Paul A [Los Alamos National Laboratory; Guyer, Robert A [UNR; Griffa, Michele [ETH ZURICH
2009-01-01
An energy current imaging method is presented for use in locating sources of wave energy during the back propagation stage of the time reversal process. During the back propagation phase of an ideal time reversal experiment, wave energy coalesces from all angles of incidence to recreate the source event; after the recreation, wave energy diverges in every direction. An energy current imaging method based on this convergence/divergence behavior has been developed. The energy current imaging method yields a smaller spatial distribution for source reconstruction than is possible with traditional energy imaging methods.
Potential Energy Total electric potential energy, U, of a system of
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Potential Energy Total electric potential energy, U, of a system of charges is obtained from of work done by the field, W*= -W. Bring q1 from , W *= 0 since no electric F yet #12;Potential Energy Total electric potential energy, U, of a system of charges is obtained from the work done by an external
Energy dependence of nucleon-nucleon potentials
Sinya Aoki; Janos Balog; Tetsuo Hatsuda; Noriyoshi Ishii; Keiko Murano; Hidekatsu Nemura; Peter Weisz
2008-12-03
We investigate the energy dependence of potentials defined through the Bethe-Salpeter wave functions. We analytically evaluate such a potential in the Ising field theory in 2 dimensions and show that its energy dependence is weak at low energy. We then numerically calculate the nucleon-nucleon potential at non-zero energy using quenched QCD with anti-periodic boundary condition. In this case we also observe that the potentials are almost identical at $E\\simeq 0$ and $E\\simeq 50$ MeV, where $E$ is the center of mass kinetic energy.
Geothermal Energy: Tapping the Potential
ERIC Educational Resources Information Center
Johnson, Bill
2008-01-01
Ground source geothermal energy enables one to tap into the earth's stored renewable energy for heating and cooling facilities. Proper application of ground-source geothermal technology can have a dramatic impact on the efficiency and financial performance of building energy utilization (30%+). At the same time, using this alternative energy…
Torquato, Salvatore
-property bounds Leonid Gibianskya) and Salvatore Torquatob) Princeton Materials Institute and Department of Civil approximations for the effective energy of nonlinear, isotropic, elastic dispersions in arbitrary space dimension. By incorporating higher-order microstruc- tural information, one can further improve upon the linear Hashin
On the physical basis for the nematic rubber elastic free energy
J. S. Biggins; M. Warner
2009-10-20
We discuss why it is physical to keep terms in the nematic rubber elastic free energy that reflect the order parameter dependence of the natural size of the network polymers. We address a point of difficulty in some mathematical approaches to this problem.
NASA Astrophysics Data System (ADS)
Lukyanov, K. V.; Lukyanov, V. K.; Kadrev, D. N.; Zemlyanaya, E. V.; Antonov, A. N.; Spasova, K.; Gaidarov, M. K.
2015-06-01
The following sections are included: * Introduction * Hybrid microscopical optical potential model * Density distributions model * 10,11Be+p elastic scattering * 11Be + 12C elastic scattering * The 11Be cluster model and momentum distributions of fragments * Final conclusions * Acknowledgements * References
NASA Astrophysics Data System (ADS)
Gregor, R. W.; Siska, P. E.
1981-01-01
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 ?=0.126 kcal/mole for Ne*+Ar, 0.192 kcal/mole for Kr, and 0.288 kcal/mole for Xe, with rm=5.0 Å 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 ? (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 1S,2 3S). The neon 3d orbital, mixed into the excited electron's orbital by exchange repulsion, appears to play a key role in this mechanistic changeover.
LEAN ENERGY ANALYSIS: IDENTIFYING, DISCOVERING AND TRACKING ENERGY SAVINGS POTENTIAL
Kissock, Kelly
LEAN ENERGY ANALYSIS: IDENTIFYING, DISCOVERING AND TRACKING ENERGY SAVINGS POTENTIAL KELLY KISSOCK DEPARTMENT OF MECHANICAL AND AEROSPACE ENGINEERING UNIVERSITY OF DAYTON DAYTON, OHIO JOHN SERYAK ENERGY AND RESOURCE SOLUTIONS HAVERHILL, MASSECHUTSETTS ABSTRACT Energy in manufacturing facilities is used for direct
Symmetric Bifurcation of Plane Frames through a Modified Potential Energy Approach
M. Pignataro; N. Rizzi; A. Di Carlo
1980-01-01
The modified potential energy approach to the nonlinear analysis of slender elastic beams is employed to investigate the buckling and postbuckling behavior of two symmetric plane frames, namely a hinged portal frame and a hinged two-bar frame, The beams are assumed to be inextensible and shear undeformable. The “hybrid” functional on which the present analysis is based according to a
Potential Energy and the Body Electric
Helmreich, Stefan
Physics tells us that potential energy is the capacity to do work that a body possesses as a result of its position in electric, magnetic, or gravitational fields. Thinking of “potentiality” in an electric idiom and with ...
Energy functions for rubber from microscopic potentials
NASA Astrophysics Data System (ADS)
Johal, A. S.; Dunstan, D. J.
2007-04-01
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.
Energy and projectile-mass dependence of light-ion potentials^
A. Nadasen; K. A. G. Rao; J. Brace; S. Balaji; P. G. Roos; P. Schwandt; J. T. Ndefru
2003-01-01
Volume integrals per nucleon pair of light-ion (A<=4) elastic scattering real potentials available in literature were calculated. Plotted as a function of energy per nucleon of the projectiles, they show a logarithmic dependence on the energy. The zero crossing for the transition from attractive to repulsive occurs at about the same energy per nucleon ( ˜600 MeV\\/A) for all projectiles.
K. Sekiguchi; H. Okamura; N. Sakamoto; H. Suzuki; M. Dozono; Y. Maeda; T. Saito; S. Sakaguchi; H. Sakai; M. Sasano; Y. Shimizu; T. Wakasa; K. Yako; H. Wita?a; W. Glöckle; J. Golak; H. Kamada; A. Nogga
2011-06-01
A complete high precision set of deuteron analyzing powers for elastic deuteron-proton ($dp$) scattering at 250 MeV/nucleon (MeV/N) has been measured. The new data are presented together with data from previous measurements at 70, 100, 135 and 200 MeV/N. They are compared with the results of three-nucleon (3N) Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three nucleon forces (3NFs): the Tucson-Melbourne 99 (TM99) and Urbana IX. At 250 MeV/N large discrepancies between pure NN models and data, which are not resolved by including 3NFs, were found at c.m.\\ backward angles of $\\theta_{\\rm c.m.}\\gtrsim 120^\\circ$ for almost all the deuteron analyzing powers. These discrepancies are quite similar to those found for the cross section at the same energy. We found small relativistic effects that cannot resolve the discrepancies with the data indicating that other, short-ranged 3NFs are required to obtain a proper description of the data.
Bazant, Martin Z.
of a wide range of models of defected crystalline and amorphous silicon are calculated, using will be very useful for predicting the effect of radiation damage on the elastic modulus of silicon. This is not surprising, given the ex- tensive uses that have been made of silicon's electronic prop- erties
Symmetryand Potential EnergySurfaces
Simons, Jack
2.1-2.3 are obeyed, the potential wen loeated at this minimum may not be deep enough to hold a bound vibrational state (if the zero-pointvibrational energyis greaterthan the dissociationenergyof the wen
Recovering elastic energy in a single-legged hopping robot
Sedal, Audrey
2015-01-01
Robots that mimic animal locomotion may be improved by the addition of compliant parts. A proposed metric for the importance of compliance in an animal gait is Ek/Ein, the ratio of the systems peak kinetic energy to the ...
Prediction of Dyke Propagation using the Minimum Potential Energy Principle
NASA Astrophysics Data System (ADS)
Heimisson, Elías; Hooper, Andrew; Sigmundsson, Freysteinn
2015-04-01
An important aspect of eruption forecasting is the prediction and monitoring of dyke propagation. Eruptions occur where dykes propagate to the surface, with lava flows causing a major threat. When such eruption occur under ice, as is common in Iceland, they become explosive and often cause hazardous and destructive floods. Dykes have also been known to trigger explosive eruption when hot basaltic magma comes in contact with more developed volatile saturated magma. Such explosive eruptions pose a danger to both lives and property. At divergent plate boundaries new crust is formed primarily by dyke injections. These injections usually grow laterally away from a central volcano. Lateral growth of a dyke is expected to follow the minimum potential energy principle. Assuming a closed system, a dyke will tend to be emplaced such that it minimizes the total potential energy, ?T, given by: ?T = ?s + ?g (1) where ?s is the strain potential and ?g the gravitational energy potential. Assuming that the elastic medium behaves linearly the strain potential can be calculated by numerically integrating the strain energy density over a large volume. If the dyke is assumed to be propagating at a constant depth with respect to sea level the gravitational potential energy can be turned into a two dimensional integral. We do this by integrating the predicted vertical displacements multiplied by the local topographic load above a reference surface and the acceleration of gravity. We approximate strain and stress due to plate movements and then consider strain changes induced by the dyke formation. Opening of a dyke is energetically favourable when it releases strain energy built up at a divergent plate boundary, but once deviatoric stress in the crust adjacent to a segment is released it becomes favourable to propagate laterally. Dyke formation is associated with uplift on their flanks; the lower the topographic load over the flanks, the less energy it costs. For any given location on a volcano, the strike of a new dyke segment will influence the strain and gravitational potential energy change in a different way. This type of model was applied to the more than 45 km long dyke formed in the Bárðarbunga volcanic system in Iceland in a rifting event in August 2014. Large observed changes in strike can be explained mostly by interplay of gravitational effects of topography and plate boundary strain. The model minimizing the total potential energy explains this propagation path. Our results suggest that by applying the total minimum potential energy principle we can forecast dyke propagation.
Energy-dependent microscopic optical potential for scattering of nucleons on light nuclei
NASA Astrophysics Data System (ADS)
Farag, M. Y. H.; Esmael, E. H.; Maridi, H. M.
2014-06-01
We present an energy-dependent microscopic optical model potential for elastic scattering of nucleons on light nuclei. The single-folding model is used for the real part of the optical potential (OP), while the imaginary part is derived within the high-energy approximation theory. The energy dependence of the OP is determined from the parameterization of the volume integrals those calculated from the best-fit OP that fit the experimental data of the cross sections and analyzing powers. This energy-dependent OP is successfully applied to analyze the proton elastic scattering of 4,6,i8He, 6,7Li, and 9,10Be nuclei at low and intermediate incident energies up to 200MeV/nucleon.
Elastic resistance change and action potential generation of non-faradaic Pt/TiO2/Pt capacitors
NASA Astrophysics Data System (ADS)
Lim, Hyungkwang; Jang, Ho Won; Lee, Doh-Kwon; Kim, Inho; Hwang, Cheol Seong; Jeong, Doo Seok
2013-06-01
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
Elastic electron scattering in krypton in the energy range from 5 to 10 eV
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
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.
Cross sections for neutron-deuteron elastic scattering in the energy range 135–250 MeV
Ertan, E.
We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from 80[degrees] to 130[degrees]. Cross sections for neutron-proton elastic ...
Potential Water and Energy Savings from Showerheads
Biermayer, Peter J.
2005-09-28
This paper estimates the benefits and costs of six water reduction scenarios. Benefits and costs of showerhead scenarios are ranked in this paper by an estimated water reduction percentage. To prioritize potential water and energy saving scenarios regarding showerheads, six scenarios were analyzed for their potential water and energy savings and the associated dollar savings to the consumer.
Nguyen, Ba Nghiep; Paquette, Joshua
2010-08-01
Fiber-reinforced polymer composites can offer important advantages over metals where lightweight, cost-effective manufacturing and high mechanical performance can be achieved. To date, these materials have not been used in hydropower systems. In view of the possibility to tailor their mechanical properties to specific applications, they now have become a subject of research for potential use in hydropower systems. The first step in any structural design that uses composite materials consists of evaluating the basic composite mechanical properties as a function of the as-formed composite microstructure. These basic properties are the elastic stiffness, stress-strain response, and strength. This report describes the evaluation of the elastic stiffness for a series of common discontinuous fiber polymer composites processed by injection molding and compression molding in order to preliminarily estimate whether these composites could be used in hydropower systems for load-carrying components such as turbine blades. To this end, the EMTA (Copyright © Battelle 2010) predictive modeling tool developed at the Pacific Northwest National Laboratory (PNNL) has been applied to predict the elastic properties of these composites as a function of three key microstructural parameters: fiber volume fraction, fiber orientation distribution, and fiber length distribution. These parameters strongly control the composite mechanical performance and can be tailored to achieve property enhancement. EMTA uses the standard and enhanced Mori-Tanaka type models combined with the Eshelby equivalent inclusion method to predict the thermoelastic properties of the composite based on its microstructure.
Rouse, Elliott J; Mooney, Luke M; Martinez-Villalpando, Ernesto C; Herr, Hugh M
2013-06-01
The cyclic and often linear torque-angle relationship of locomotion presents the opportunity to innovate on the design of traditional series-elastic actuators (SEAs). In this paper, a novel modification to the SEA architecture was proposed by adding a clutch in parallel with the motor within the SEA--denoted as a CSEA. This addition permits bimodal dynamics where the system is characterized by an SEA when the clutch is disengaged and a passive spring when the clutch is engaged. The purpose of the parallel clutch was to provide the ability to store energy in a tuned series spring, while requiring only reactionary torque from the clutch. Thus, when the clutch is engaged, a tuned elastic relationship can be achieved with minimal electrical energy consumption. The state-based model of the CSEA is introduced and the implementation of the CSEA mechanism in a powered knee prosthesis is detailed. The series elasticity was optimized to fit the spring-like torque-angle relationship of early stance phase knee flexion and extension during level ground walking. In simulation, the CSEA knee required 70% less electrical energy than a traditional SEA. Future work will focus on the mechanical implementation of the CSEA knee and an empirical demonstration of reduced electrical energy consumption during walking. PMID:24187202
On the Chemical Potential of Dark Energy
S. H. Pereira
2008-06-23
It is widely assumed that the observed universe is accelerating due to the existence of a new fluid component called dark energy. In this article, the thermodynamics consequences of a nonzero chemical potential on the dark energy component is discussed with special emphasis to the phantom fluid case. It is found that if the dark energy fluid is endowed with a negative chemical potential, the phantom field hypothesis becomes thermodynamically consistent with no need of negative temperatures as recently assumed in the literature.
An energy absorbing far-field boundary condition for the elastic wave equation
Petersson, N A; Sjogreen, B
2008-07-15
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.
Chapter 10. Energy This pole vaulter can lift
Dhamala, Mukesh
by transforming the kinetic energy of her run into gravitational potential energy.potential energy. Chapter Goal Potential Energy Â· A Closer Look at Gravitational Potential Chapter 10. Energy Â· A Closer Look at Gravitational Potential Energy Â· Restoring Forces and Hooke's Law Â· Elastic Potential Energy Â· Elastic
Photodissociation of methane: Exploring potential energy surfaces
Rob van Harrevelt
2006-01-01
The potential energy surface for the first excited singlet state (S1) of methane is explored using multireference singles and doubles configuration interaction calculations, employing a valence triple zeta basis set. A larger valence quadruple zeta basis is used to calculate the vertical excitation energy and dissociation energies. All stationary points found on the S1 surface are saddle points and have
Geothermal Energy Potential in Western United States
ERIC Educational Resources Information Center
Pryde, Philip R.
1977-01-01
Reviews types of geothermal energy sources in the western states, including hot brine systems and dry steam systems. Conversion to electrical energy is a major potential use of geothermal energy, although it creates environmental disruptions such as noise, corrosion, and scaling of equipment. (AV)
NASA Astrophysics Data System (ADS)
Deur, Alexandre
1999-10-01
The Jefferson Lab beam energy measurement in Hall A using the elastic ep scattering will be described. This new, non-magnetic, energy measurement method allows a ( triangle E/E=10-4 ) precision. First-order corrections are canceled by the measurements of the electron and proton scattering angles for two symmetric kinematics. The measurement principle will be presented as well as the device and measurement results. Comparison with independent magnetic energy measurements of the same accuracy will be shown. This project is the result of a collaboration between the LPC: université Blaise Pascal/in2p3), Saclay and Jefferson Lab.
Kang, Yue; Wang, Bo; Dai, Shuge; Liu, Guanlin; Pu, Yanping; Hu, Chenguo
2015-09-16
A folded elastic strip-based triboelectric nanogenerator (FS-TENG) made from two folded double-layer elastic strips of Al/PET and PTFE/PET can achieve multiple functions by low frequency mechanical motion. A single FS-TENG with strip width of 3 cm and length of 27 cm can generate a maximum output current, open-circuit voltage, and peak power of 55 ?A, 840 V, and 7.33 mW at deformation frequency of 4 Hz with amplitude of 2.5 cm, respectively. This FS-TENG can work as a weight sensor due to its good elasticity. An integrated generator assembled by four FS-TENGs (IFS-TENG) can harvest the energy of human motion like flapping hands and walking steps. In addition, the IFS-TENG combined with electromagnetically induced electricity can achieve a completely self-driven doorbell with flashing lights. Moreover, a box-like generator integrated by four IFS-TENGs inside can work in horizontal or random motion modes and can be improved to harvest energy in all directions. This work promotes the research of completely self-driven systems and energy harvesting of human motion for applications in our daily life. PMID:26305461
Elastic Strain Energy Storage and Neighboring Organ Assistance for Fluid Propulsion
NASA Astrophysics Data System (ADS)
Arun, C. P.
2003-11-01
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.
Outstanding mechanical properties of monolayer MoS2 and its application in elastic energy storage
NASA Astrophysics Data System (ADS)
Peng, Qing; de, Suvranu
2014-03-01
The structural and mechanical properties of graphene-like honeycomb monolayer structures of MoS2(g-MoS2) under various large strains are investigated using density functional theory (DFT). g-MoS2 is mechanically stable and can sustain extra large strains: the ultimate strains are 0.24, 0.37, and 0.26 for armchair, zigzag, and biaxial deformation, respectively. The in-plane stiffness is as high as 120 N/m (184 GPa equivalently). The third, fourth, and fifth order elastic constants are indispensable for accurate modeling of the mechanical properties under strains larger than 0.04, 0.07, and 0.13 respectively. The second order elastic constants, including in-plane stiffness, are predicted to monotonically increase with pressure while the Poisson ratio monotonically decreases with increasing pressure. With the prominent mechanical properties including large ultimate strains and in-plane stiffness, g-MoS2 is a promising candidate of elastic energy storage for clean energy. It possesses a theoretical energy storage capacity as high as 8.8 MJ/L and 1.7 MJ/kg, or 476 Wh/kg, larger than a Li-ion battery and is environmentally friendly. Financial support from the Defence Threat Reduction Agency (DTRA) Grant # BRBAA08-C-2-0130 and.
NASA Astrophysics Data System (ADS)
Sycheva, A. A.; Balint-Kurti, G. G.; Palov, A. P.
2014-11-01
The potential of interaction between oxygen and silicon atoms in a range of interatomic distances within 0.75-11.5 au has been calculated from first principles (ab initio) using the multiconfigurational interaction (MRCI) method with the aug-pp-AVQZ basis set of atomic wave functions. An analytical approximation of the numerically calculated potential is presented. The elastic scattering of oxygen on silicon was studied in the 10-500 eV range of relative kinetic energies. The obtained differential, integral, and transport scattering cross sections and the proposed interatomic potential can be used in the field of nanotechnologies.
Gomez Camacho, A.; Gomes, P. R. S.; Lubian, J.; Padron, I.
2008-05-15
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.
Energy potential of modern landfills
Bogner, J.E.
1990-01-01
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.
Fazzalari, Nicola L.
2009-01-01
Elastic fibres are critical constituents of dynamic biological structures that functionally require elasticity and resilience. The network of elastic fibres in the anulus fibrosus of the intervertebral disc is extensive, however until recently, the majority of histological, biochemical and biomechanical studies have focussed on the roles of other extracellular matrix constituents such as collagens and proteoglycans. The resulting lack of detailed descriptions of elastic fibre network architecture and mechanical function has limited understanding of the potentially important contribution made by elastic fibres to healthy disc function and their possible roles in the progression of disc degeneration. In addition, it has made it difficult to postulate what the consequences of elastic fibre related disorders would be for intervertebral disc behaviour, and to develop treatments accordingly. In this paper, we review recent and historical studies which have examined both the structure and the function of the human lumbar anulus fibrosus elastic fibre network, provide a synergistic discussion in an attempt to clarify its potentially critical contribution both to normal intervertebral disc behaviour and the processes relating to its degeneration, and recommend critical areas for future research. PMID:19263091
Effective Potential Energy Expression for Membrane Transport
Robert W. Finkel
2007-02-11
All living cells transport molecules and ions across membranes, often against concentration gradients. This active transport requires continual energy expenditure and is clearly a nonequilibrium process for which standard equilibrium thermodynamics is not rigorously applicable. Here we derive a nonequilibrium effective potential that evaluates the per particle transport energy invested by the membrane. A novel method is used whereby a Hamiltonian function is constructed using particle concentrations as generalized coordinates. The associated generalized momenta are simply related to the individual particle energy from which we identify the effective potential. Examples are given and the formalism is compared with the equilibrium Gibb's free energy.
Multivessel Batch Distillation -Potential Energy Savings
Skogestad, Sigurd
Multivessel Batch Distillation - Potential Energy Savings Bernd Wittgens and Sigurd Skogestad 1, Norway ABSTRACT - A conventional batch distillation column operated under feedback control applying the proposed policy is compared to the multivessel batch distillation column. In some cases we found
Multivessel Batch Distillation Potential Energy Savings
Skogestad, Sigurd
Multivessel Batch Distillation Potential Energy Savings Bernd Wittgens and Sigurd Skogestad 1, Norway ABSTRACT A conventional batch distillation column operated under feedback control applying the proposed policy is compared to the multivessel batch distillation column. In some cases we found
Bosco, C; Rusko, H
1983-11-01
The enhancement of performance in stretch-shortening exercises has been attributed to the recoil of elastic energy stored during the stretching phase. If the time between stretching and shortening (coupling time) is too long the stored elastic energy can be wasted. In the present study, coupling time was increased by asking ten male subjects to run on a treadmill at different speeds (2.2-5.2 m X s-1) using special soft shoes in addition to normal shoes. The results indicated that running with soft shoes required greater energy consumption than running with normal shoes except at slow speed (2.2 m X s-1). When the running speed was increased the extra energy consumed using soft shoes was parallelly enhanced (0.4 J X kg-1/step at 5.2 m X s-1). It was suggested that the effect of coupling time as limiting factor for recoil of elastic energy was relevant in fast twitch (FT) fibers, which were progressively recruited when the running speed was increased. This is consistent to the fact that cross-bridge life time in FT fibers is very short, and therefore more sensitive to coupling time. At slow running speed (2.2 m X s-1) only slow twitch (ST) fibers were recruited and the enhancement of coupling time was not long enough to provocate detachment of cross-bridges of ST fibers, which possess a long cross-bridge life time. It was concluded that the different recruitment of ST and FT fibers influenced the pattern of recoil of elastic energy which was dependent on the running speed. PMID:6659989
Size-dependent reversal of the elastic interaction energy between misfit nanostructures
NASA Astrophysics Data System (ADS)
Persichetti, L.; Sgarlata, A.; Fanfoni, M.; Balzarotti, A.
2013-02-01
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.
The Intermediate Energy Elastic Scattering of Protons by ?-CLUSTER 20Ne and 24Mg Nuclei
NASA Astrophysics Data System (ADS)
Berezhnoy, Yu. A.; Mikhailyuk, V. P.; Pilipenko, V. V.
The multiple diffraction scattering theory and the ?-cluster model with dispersion have been applied for calculations of the observables for the elastic scattering of intermediate energy protons by 20Ne and 24Mg nuclei. The target nuclei are considered as composed of the core (16O nucleus) and additional ?-clusters (one ?-cluster for 20Ne nucleus and a dumb-bell ?-cluster configuration for 24Mg nucleus). Taking into account the ?-cluster configuration of the core, it was supposed that the additional ?-cluster or center of mass of the dumb-bell are arranged with the most probability inside or outside of the core. The calculated observables for the elastic p-20Ne and p-24Mg scattering are in agreement with the existing experimental data. The influence of the deformed core contribution on the behavior of the calculated observables also is tested.
Size-dependent reversal of the elastic interaction energy between misfit nanostructures.
Persichetti, L; Sgarlata, A; Fanfoni, M; Balzarotti, A
2013-02-20
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
Neural network models of potential energy surfaces
Thomas B. Blank; Steven D. Brown; August W. Calhoun; Douglas J. Doren
1995-01-01
Neural networks provide an efficient, general interpolation method for nonlinear functions of several variables. This paper describes the use of feed-forward neural networks to model global properties of potential energy surfaces from information available at a limited number of configurations. As an initial demonstration of the method, several fits are made to data derived from an empirical potential model of
Bohm's Quantum Potential as an Internal Energy
Glen Dennis; Maurice de Gosson; Basil Hiley
2014-12-15
We pursue our discussion of Fermi's surface initiated in Dennis, de Gosson and Hiley and show that Bohm's quantum potential can be viewed as an internal energy of a quantum system. This gives further insight into the role it played by the quantum potential in stationary states. It also allows us to provide a physically motivated derivation of Schr\\"odinger's equation for a particle in an external potential.
Synergy of elastic and inelastic energy loss on ion track formation in SrTiO?.
Weber, William J; Zarkadoula, Eva; Pakarinen, Olli H; Sachan, Ritesh; Chisholm, Matthew F; Liu, Peng; Xue, Haizhou; Jin, Ke; Zhang, Yanwen
2015-01-01
While the interaction of energetic ions with solids is well known to result in inelastic energy loss to electrons and elastic energy loss to atomic nuclei in the solid, the coupled effects of these energy losses on defect production, nanostructure evolution and phase transformations in ionic and covalently bonded materials are complex and not well understood due to dependencies on electron-electron scattering processes, electron-phonon coupling, localized electronic excitations, diffusivity of charged defects, and solid-state radiolysis. Here we show that a colossal synergy occurs between inelastic energy loss and pre-existing atomic defects created by elastic energy loss in single crystal strontium titanate (SrTiO?), resulting in the formation of nanometer-sized amorphous tracks, but only in the narrow region with pre-existing defects. These defects locally decrease the electronic and atomic thermal conductivities and increase electron-phonon coupling, which locally increase the intensity of the thermal spike for each ion. This work identifies a major gap in understanding on the role of defects in electronic energy dissipation and electron-phonon coupling; it also provides insights for creating novel interfaces and nanostructures to functionalize thin film structures, including tunable electronic, ionic, magnetic and optical properties. PMID:25578009
A method to estimate the elastic energy stored in braided DNA molecules using hydrodynamic equations
NASA Astrophysics Data System (ADS)
Fernández-Sierra, Mónica; Delgado-Martí, Violeta; Colón-García, Jorge E.; Quiñones, Edwin
2011-05-01
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.
Differential Cross Section of DP-Elastic Scattering at Intermediate Energies
N. B. Ladygina
2009-06-10
The deuteron-proton elastic scattering is studied in the multiple scattering expansion formalism. The contributions of the one-nucleon-exchange, single- and double scattering are taken into account. The Love and Franey parameterization of the nucleon-nucleon $t$-matrix is used, that gives an opportunity to include the off-energy-shell effects into calculations. Differential cross sections are considered at four energies, $T_d=390, 500, 880, 1200$ MeV. The obtained results are compared with the experimental data.
NASA Astrophysics Data System (ADS)
Takaoka, Masanori; Yokoyama, Naoto
2015-01-01
The real-space dynamics and the nonlinear interactions among Fourier modes in elastic wave turbulence are investigated by simulating the Foppl-von Karman equation. We find that the bundle structures of ridges appear intermittently in the time evolution of the stretching energy field. The time-evolution of the nonlinearity indicates the existence of active and moderate phases in turbulent state. Conditional sampling analysis reveals that the bundle structure, which is the embodiment of the strong nonlinear interactions among modes, induces the energy supply from an external force to the system.
Low-energy elastic electron scattering from chloromethane, CH3Cl
NASA Astrophysics Data System (ADS)
Navarro, C.; Sakaamini, A.; Cross, J.; Hargreaves, L. R.; Khakoo, M. A.; Fedus, Kamil; Winstead, C.; McKoy, V.
2015-10-01
We report theoretical as well as (normalized) experimental differential and integral cross sections for vibrationally elastic scattering of low-energy electrons from chloromethane, CH3Cl, also known as methyl chloride. The theoretical cross sections were computed using the Schwinger multichannel variational method in the single-channel approximation, with polarization effects included via virtual excitations. Cross section measurements were made at incident energies ranging from 0.5 to 100 eV and at scattering angles from {5}\\circ to {125}\\circ . We compare our data to earlier previous results for this molecule.
Low-energy elastic electron scattering form chloroethane, C2H5Cl
NASA Astrophysics Data System (ADS)
Sakaamini, A.; Navarro, C.; Cross, J.; Hargreaves, L. R.; Khakoo, M. A.; Fedus, Kamil; Winstead, C.; McKoy, V.
2015-10-01
We report theoretical as well as (normalized) experimental differential and integral cross sections for vibrationally elastic scattering of low-energy electrons from chloroethane, C2H5Cl, also known as ethyl chloride. The theoretical cross sections were computed using the Schwinger multichannel variational method in the single-channel approximation, with polarization effects included via virtual excitations. Cross section measurements were made at incident energies ranging from 1 to 30 eV and at scattering angles from {10}\\circ to {125}\\circ . We compare our data to previous results for C2H5Cl and for the related molecule chloromethane.
NASA Astrophysics Data System (ADS)
Ma, Er-Jun; Ma, Yu-Gang; Cai, Xiang-Zhou; Fang, De-Qing; Shen, Wen-Qing; Tian, Wen-Dong
2007-11-01
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.
Potential of energy production from conserved forages
Technology Transfer Automated Retrieval System (TEKTRAN)
Forages have a potential role in meeting the demand for energy. Perennial forages are attractive for various reasons. One, both the monetary and energy cost of planting is spread over many years. Two, we already have the equipment for harvesting, storing and transporting this source of biomass. Thre...
Nonlinear elastic effects on the energy flux deviation of ultrasonic waves in gr/ep composites
NASA Technical Reports Server (NTRS)
Prosser, William H.; Kriz, R. D.; Fitting, Dale W.
1992-01-01
The effects of nonlinear elasticity on energy flux deviation in undirectional gr/ep composites are examined. The shift in the flux deviation is modeled using acoustoelasticity theory and the second- and third-order elastic stiffness coefficients for T300/5208 gr/ep. Two conditions of applied uniaxial stress are considered. In the first case, the direction of applied uniaxial stress was along the fiber axis (x3), while in the second case it was perpendicular to the fiber axis along the laminate stacking direction (x1). For both conditions, the change in the energy flux deviation angle from the condition of zero applied stress is computed over the range of propagation directions of 0 to 60 deg from the fiber axis at two-degree intervals. A positive flux deviation angle implies the energy deviates away from the fiber direction toward the x1 axis, while a negative deviation means that the energy deviates toward the fibers. Over this range of fiber orientation angles, the energy of the quasi-longitudinal and pure mode transverse waves deviates toward the fibers, while that of the quasi-transverse mode deviates away from the fibers.
Applying supersymmetry to energy dependent potentials
Yekken, R. [Faculté de Physique, USTHB Bab Ezzouar, Alger (Algeria)] [Faculté de Physique, USTHB Bab Ezzouar, Alger (Algeria); Lassaut, M. [Groupe de Physique Théorique, Institut de Physique Nucléaire, IN2P3 - CNRS, Université Paris-Sud 11, 91406 Orsay Cedex (France)] [Groupe de Physique Théorique, Institut de Physique Nucléaire, IN2P3 - CNRS, Université Paris-Sud 11, 91406 Orsay Cedex (France); Lombard, R.J., E-mail: roland.lombard@laposte.net [Groupe de Physique Théorique, Institut de Physique Nucléaire, IN2P3 - CNRS, Université Paris-Sud 11, 91406 Orsay Cedex (France)
2013-11-15
We investigate the supersymmetry properties of energy dependent potentials in the D=1 dimensional space. We show the main aspects of supersymmetry to be preserved, namely the factorization of the Hamiltonian, the connections between eigenvalues and wave functions of the partner Hamiltonians. Two methods are proposed. The first one requires the extension of the usual rules via the concept of local equivalent potential. In this case, the superpotential becomes depending on the state. The second method, applicable when the potential depends linearly on the energy, is similar to what has been already achieved by means of the Darboux transform. -- Highlights: •Supersymmetry extended to energy dependent potentials. •Generalization of the concept of superpotential. •An alternative method used for linear E-dependence leads to the same results as Darboux transform.
Economic Energy Savings Potential in Federal Buildings
Brown, Daryl R.; Dirks, James A.; Hunt, Diane M.
2000-09-04
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.
Trajectory integration with potential energy discontinuities
Hurd, Patricia; Cusati, Teresa; Persico, Maurizio
2010-03-20
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.
Quantum potential energy as concealed motion
Peter Holland
2014-11-13
It is known that the Schroedinger equation may be derived from a hydrodynamic model in which the Lagrangian position coordinates of a continuum of particles represent the quantum state. Using Routh\\s method of ignorable coordinates it is shown that the quantum potential energy of particle interaction that represents quantum effects in this model may be regarded as the kinetic energy of additional concealed freedoms. The method brings an alternative perspective to Planck\\s constant, which plays the role of a hidden variable, and to the canonical quantization procedure, since what is termed kinetic energy in quantum mechanics may be regarded literally as energy due to motion.
Polarization observables in dp backward elastic scattering at high and intermediate energies
M. Tanifuji; S. Ishikawa; Y. Iseri
1997-01-28
The tensor analyzing power $T_{20}$ and the polarization transfer coefficients $\\kappa_0 (= 3/2 K_y^y)$ and $K_{xz}^y$ are investigated for dp backward elastic scattering by the invariant-amplitude method. Discrepancies between the conventional calculations and the experimental data on $T_{20}$ and $\\kappa_0$ at high and intermediate energies are mostly dissolved by including imaginary parts in the amplitudes. The quantity $K_{xz}^y$ is shown to be useful in criticizing nuclear force assumptions.
Search for dark energy potentials in quintessence
NASA Astrophysics Data System (ADS)
Muromachi, Yusuke; Okabayashi, Akira; Okada, Daiki; Hara, Tetsuya; Itoh, Yutaka
2015-09-01
The time evolution of the equation of state w for quintessence models with a scalar field as dark energy is studied up to the third derivative big (d^3w/da^3big ) with respect to the scale factor a, in order to predict future observations and specify the scalar potential parameters with the observables. The third derivative of w for general potential V is derived and applied to several types of potentials. They are the inverse power law big (V=M^{4+? }/Q^{? }big ), the exponential big (V=M^4exp {? M/Q}big ), the mixed big (V=M^{4+? }exp {? M/Q}/Q^{? }big ), the cosine big (V=M^4[cos (Q/f)+1]big ), and the Gaussian types big (V=M^4exp big {-Q^2/? ^2big }big ), which are prototypical potentials for the freezing and thawing models. If the parameter number for a potential form is n, it is necessary to find at least n+2 independent observations to identify the potential form and the evolution of the scalar field (Q and dot {Q}). Such observations would be the values of ? _Q, w, dw/da,ldots , dw^n/da^n. From these specific potentials, we can predict the n+1 and higher derivatives of w: dw^{n+1}/da^{n+1},ldots . Since four of the abovementioned potentials have two parameters, it is necessary to calculate the third derivative of w for them to estimate the predicted values. If they are tested observationally, it will be understood whether the dark energy can be described by a scalar field with this potential. At least it will satisfy the necessary conditions. Numerical analysis for d^3w/da^3 is performed with some specified parameters in the investigated potentials, except for the mixed one. It becomes possible to distinguish the potentials by accurately observing dw/da and d^2w/da^2 for some parameters.
Experimental study of {sup 6}He+{sup 9}Be elastic scattering at low energies
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.
2011-06-15
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.
Potential energy surfaces for cluster emitting nuclei
Dorin N. Poenaru; Radu A. Gherghescu; Walter Greiner
2005-09-26
Potential energy surfaces are calculated by using the most advanced asymmetric two-center shell model allowing to obtain shell and pairing corrections which are added to the Yukawa-plus-exponential model deformation energy. Shell effects are of crucial importance for experimental observation of spontaneous disintegration by heavy ion emission. Results for 222Ra, 232U, 236Pu and 242Cm illustrate the main ideas and show for the first time for a cluster emitter a potential barrier obtained by using the macroscopic-microscopic method.
F. A. Gianturco; G. Niedner; M. Noll; E. Semprini; F. Stefani; J. P. Toennies
1987-01-01
The ground state potential energy curves for protons interacting with Ar and Ne atoms are determined by the analysis of new, highly accurate measurements of the elastic differential cross sections at a laboratory collision energy of 14.8 eV. Accompanying theoretical results from SCF-CI calculations are used as starting points to generate analytic potentials that are able to fit all available
Nudged-elastic band used to find reaction coordinates based on the free energy
NASA Astrophysics Data System (ADS)
Bohner, Matthias U.; Zeman, Johannes; Smiatek, Jens; Arnold, Axel; Kästner, Johannes
2014-02-01
Transition paths characterize chemical reaction mechanisms. In this paper, we present a new method to find mean reaction paths based on the free energy. A nudged elastic band (NEB) is optimized using gradients and Hessians of the free energy, which are obtained from umbrella integration. The transition state can be refined by a Newton-Raphson search starting from the highest point of the NEB path. All optimizations are done using Cartesian coordinates. Independent molecular dynamics (MD) runs are performed at each image used to discretize the path. This makes the method intrinsically parallel. In contrast to other free energy methods, the algorithm does not become more expensive when including more degrees of freedom in the active space. The method is applied to the alanine-dipeptide as a test case and compared to pathways that have been derived from metadynamics and forward flux sampling.
Searching for Saddle Points of Potential Energy Surfaces by
Quapp, Wolfgang
-- --Potential Energy Surfaces by Following a Reduced Gradient of the potential energy surface PES , is reduced by one equation corresponding to one search direction Keywords: saddle point; distinguished coordinate; valley-ridge inflection point; H CO potential energy
Andrew P. Graham; J. Peter Toennies
1999-01-01
The lateral potential energy surface for adsorbed atoms and molecules is important for a detailed understanding of diffusion, sliding friction, catalysis, and molecular beam epitaxy. In this brief review, it is shown that the analysis of quasi-elastic helium scattering data, in addition to the complementary inelastic results for parallel translational vibrations, leads to a detailed description of the potential energy
Energy scavenging from acousto-elastic metamaterial using local resonance phenomenon
NASA Astrophysics Data System (ADS)
Ahmed, Riaz U.; Adiba, Afifa; Banerjee, Sourav
2015-04-01
This article presents the possibility of energy scavenging (ES) utilizing the physics of acousto-elastic metamaterial (AEMM) and use them in a dual mode (Acoustic Filter and Energy Harvester), simultaneously. Concurrent wave filtering and energy harvesting mechanism is previously presented using local resonance phenomenon in phononic crystal, however energy harvesting capabilities of AEMM is not reported extensively. Traditionally acoustic metamaterials are used in filtering acoustic waves by trapping or guiding the acoustic energy, whereas this work presents that the trapped dynamic energy inside the soft constituent (matrix) of metamaterials can be significantly harvested by strategically embedding piezoelectric wafers in the matrix. With unit cell model, we asserted that at lower acoustic frequencies maximum power in the micro Watts (~36?W) range can be generated, which is significantly higher than the existing harvesters of same kind. Efficient energy scavengers at low acoustic frequencies are almost absent due to large required size relevant to the acoustic wavelength. In this work we propose sub wave length scale energy scavengers utilizing the coupled physics of local, structural and matrix resonances. Upon validation of the argument through analytical, numerical and experimental studies, a broadband energy scavenger (ES) with multi-cell model is designed with varying geometrical properties.
Optical Potentials by Inversion for 16O Ion Elastic Scatterings at Elab=1503 MeV
NASA Astrophysics Data System (ADS)
Kim, Yong Joo; Cha, Moon Hoe
The optical potentials by inversion are presented in two ways. The first one is to use the inverse eikonal relations derived from McIntyre phase shifts. The second one is to solve the inversion problem based on McIntyre parametrization of S-matrix corresponding to the Woods-Saxon type optical potentials. The optical potentials obtained from the two inversion methods are applied to the systems 16O+12C, 16O+28Si, and 16O+40Ca at Elab=1503 MeV. The calculated results are compared with those from the optical model analysis. It is shown that both the two methods lead to reasonable agreements, in the surface region, to the results from the optical model analysis.
NASA Technical Reports Server (NTRS)
Bernstein, R. B.; Labudde, R. A.
1972-01-01
The problem of inversion is considered in relation to absolute total cross sections Q(v) for atom-atom collisions and their velocity dependence, and the glory undulations and the transition to high velocity behavior. There is a limit to the amount of information available from Q(v) even when observations of good accuracy (e.g., + or - 0.25%) are in hand over an extended energy range (from thermal energies upward by a factor of greater than 1000 in relative kinetic energy). Methods were developed for data utilization, which take full advantage of the accuracy of the experimental Q(v) measurements.
Lai, Adrian; Schache, Anthony G; Lin, Yi-Chung; Pandy, Marcus G
2014-09-01
The human ankle plantar-flexors, the soleus and gastrocnemius, utilize tendon elastic strain energy to reduce muscle fiber work and optimize contractile conditions during running. However, studies to date have considered only slow to moderate running speeds up to 5 m s(-1). Little is known about how the human ankle plantar-flexors utilize tendon elastic strain energy as running speed is advanced towards maximum sprinting. We used data obtained from gait experiments in conjunction with musculoskeletal modeling and optimization techniques to calculate muscle-tendon unit (MTU) work, tendon elastic strain energy and muscle fiber work for the ankle plantar-flexors as participants ran at five discrete steady-state speeds ranging from jogging (~2 m s(-1)) to sprinting (?8 m s(-1)). As running speed progressed from jogging to sprinting, the contribution of tendon elastic strain energy to the positive work generated by the MTU increased from 53% to 74% for the soleus and from 62% to 75% for the gastrocnemius. This increase was facilitated by greater muscle activation and the relatively isometric behavior of the soleus and gastrocnemius muscle fibers. Both of these characteristics enhanced tendon stretch and recoil, which contributed to the bulk of the change in MTU length. Our results suggest that as steady-state running speed is advanced towards maximum sprinting, the human ankle plantar-flexors continue to prioritize the storage and recovery of tendon elastic strain energy over muscle fiber work. PMID:24948642
Wind energy potential in the United States
D. L. Elliott; M. N. Schwartz
1993-01-01
Estimates of the electricity that could potentially be generated by wind power and of the land area available for wind energy development have been calculated for the contiguous United States. The estimates are based on published wind resource data and exclude windy lands that are not suitable for development as a result of environmental and land-use considerations. Despite these exclusions,
Potential energy surfaces of CH4(+)
Regina F. Frey; Ernest R. Davidson
1988-01-01
The potential energy surfaces of the three lowest electronic states of CH4(+) are calculated. CI calculations based on average natural orbitals from preliminary multireference singles and doubles CI calculations are found to provide a balanced description of the three states. The calculated points are fit to the eigenvalues of a 3 x 3 matrix whose elements are a power-series expansion
POTENTIAL ENERGY SAVINGS OF MULTIVESSEL BATCH DISTILLATION
Skogestad, Sigurd
POTENTIAL ENERGY SAVINGS OF MULTIVESSEL BATCH DISTILLATION Bernd Wittgens and Sigurd Skogestad 1, Norway ABSTRACT - A conventional batch distillation column operated under feedback control applying the proposed policy is compared to the multivessel batch distillation column. In some cases we found
POTENTIAL ENERGY SAVINGS OF MULTIVESSEL BATCH DISTILLATION
Skogestad, Sigurd
POTENTIAL ENERGY SAVINGS OF MULTIVESSEL BATCH DISTILLATION Bernd Wittgens and Sigurd Skogestad 1, Norway ABSTRACT A conventional batch distillation column operated under feedback control applying the proposed policy is compared to the multivessel batch distillation column. In some cases we found
Paulino, Glaucio H.
The meshless hypersingular boundary node method for three-dimensional potential theory and linear) approximants. The main idea here is to retain the dimensionality advantage of the former and the meshless- ciated with 3-D meshing. These methods have been collec- tively referred to as `meshfree' or `meshless
NASA Astrophysics Data System (ADS)
Li, Lian He; You Fan, Tian
2006-11-01
The plane elasticity equations of two-dimensional quasicrystals of point group 10 are reduced to a single partial differential equation with eighth order by introducing a stress potential function. Further, we develop the complex variable function method for classical elasticity theory to that of the quasicrystals. The complex representations of stress and displacement components of phonon and phason fields in the quasicrystals are given. With the help of conformal transformation, an exact solution for the elliptic notch of the quasicrystals is presented. The solution of the Griffith crack problem as a special case of the results is also observed. This work shows that the stress potential and complex variable function methods are powerful for solving the complicated boundary value problems of higher order partial differential equations originating from quasicrystal elasticity.
Low frequency energy scavenging using sub-wave length scale acousto-elastic metamaterial
NASA Astrophysics Data System (ADS)
Ahmed, Riaz U.; Banerjee, Sourav
2014-11-01
This letter presents the possibility of energy scavenging (ES) utilizing the physics of acousto-elastic metamaterial (AEMM) at low frequencies (<˜3KHz). It is proposed to use the AEMM in a dual mode (Acoustic Filter and Energy Harvester), simultaneously. AEMM's are typically reported for filtering acoustic waves by trapping or guiding the acoustic energy, whereas this letter shows that the dynamic energy trapped inside the soft constituent (matrix) of metamaterials can be significantly harvested by strategically embedding piezoelectric wafers in the matrix. With unit cell AEMM model, we experimentally asserted that at lower acoustic frequencies (< ˜3 KHz), maximum power in the micro Watts (˜35µW) range can be generated, whereas, recently reported phononic crystal based metamaterials harvested only nano Watt (˜30nW) power against 10K? resistive load. Efficient energy scavengers at low acoustic frequencies are almost absent due to large required size relevant to the acoustic wavelength. Here we report sub wave length scale energy scavengers utilizing the coupled physics of local, structural and matrix resonances. Upon validation of the argument through analytical, numerical and experimental studies, a multi-frequency energy scavenger (ES) with multi-cell model is designed with varying geometrical properties capable of scavenging energy (power output from ˜10µW - ˜90µW) between 0.2 KHz and 1.5 KHz acoustic frequencies.
Elastic cross sections for Mn, Ni, Cu, Zn, Ag and Cd atoms by low energy electrons
NASA Astrophysics Data System (ADS)
Msezane, A. Z.; Felfli, Z.; Sokolovski, D.
2011-05-01
There is a great need for a fundamental understanding of the mechanism of the near-threshold electron attachment to the atoms Mn, Ni, Cu, Zn, Ag and Cd, particularly the identification and characterization of the attendant resonance structures in the electron elastic total cross sections (TCSs). The crucial electron-electron correlations and core-polarization interactions, vital to the existence and stability of most negative ions, render understanding the structure and the dynamics of low-energy electron elastic collisions resulting in the formation of negative ions as resonances, quite challenging for conventional theoretical methods. Here we have investigated using the successful complex angular momentum (CAM) method, the TCSs for Mn, Ni, Cu, Zn, Ag and Cd in the energy range 0 <= E <= 1 eV to identify and delineate the resonance structures and minima. The imaginary part of the CAM is used to distinguish between the stable bound states of the negative ions (long-lived resonances) and the shape resonances (short-lived resonances). TCSs, Ramsauer-Townsend minima, shape resonances and BEs are presented. Supported by U.S. DOE, AFOSR and CAU CFNM, NSF-CREST.
Biomass resource potential using energy crops
Wright, L.L.; Cushman, J.H.; Martin, S.A.
1993-09-01
Biomass energy crops can provide a significant and environmentally beneficial source of renewable energy feedstocks for the future. They can revitalize the agricultural sector of the US economy by providing profitable uses for marginal cropland. Energy crops include fast-growing trees, perennial grasses, and annual grasses, all capable of collecting solar energy and storing it as cellulosic compounds for several months to several years. Once solar energy is thus captured, it can be converted by means of currently available technologies to a wide variety of energy products such as electricity, heat, liquid transportation fuels, and gases. Experimental results from field trials have generated optimism that selected and improved energy crops, established on cropland with moderate limitations for crop production, have the potential for producing high yields. Both trees and grasses, under very good growing conditions, have produced average annual yields of 20 to 40 dry Mg ha{sup {minus}1} year{sup {minus}1}. Sorghum has shown especially high yields in the Midwest. Hybrids between sugar cane and its wild relatives, called energy cane, have yielded as much as 50 dry Mg ha{sup {minus}1} year{sup {minus}1} in Florida. These experimental results demonstrate that some species have the genetic potential for very rapid growth rates. New wood energy crop systems developed by the Department of Energy`s Biofuels Feedstock Development Program offer, at a minimum, a 100% increase in biomass production rates over the 2 to 4 Mg ha{sup {minus}1} year{sup {minus}1} of dry leafless woody biomass produced by most natural forest systems. Experimental data indicate that short rotation wood crops established on cropland with moderate limitations are capable of producing biomass yields of 8--20 dry Mg ha{sup {minus}1} year{sup {minus}1} with a present average about 11 dry Mg ha{sup {minus}1} year{sup {minus}1} on typical cropland sites.
Low-energy electron elastic scattering from Os atom: New electron affinity
NASA Astrophysics Data System (ADS)
Felfli, Z.; Kiros, F.; Msezane, A. Z.
2013-05-01
Bilodeau and Haugan measured the binding energies (BEs) of the ground state and the excited state of the Os- ion to be 1.07780(12) eV and 0.553(3) eV, respectively. These values are consistent with those calculated in. Here our investigation, using the recent complex angular momentum methodology wherein is embedded the crucial electron-electron correlations and the vital core polarization interaction, has found that the near threshold electron-Os elastic scattering total cross section (TCS) is characterized by three stable bound states of the Os- ion formed as resonances during the slow electron collision, with BEs of 1.910 eV, 1.230 eV and 0.224 eV. The new extracted electron affinity (EA) value from the TCS of 1.910 eV for the Os atom is significantly different from that measured in. Our calculated elastic differential cross sections (DCSs) also yield the relevant BEs for the ground and the two excited states of the Os- ion. The complex characteristic resonance structure in the TCS for the Os atom is ideal for catalysis, but makes it difficult to execute the Wigner threshold law in describing the threshold detachment behavior of complex atoms and extracting the reliable attendant EAs. Bilodeau and Haugan measured the binding energies (BEs) of the ground state and the excited state of the Os- ion to be 1.07780(12) eV and 0.553(3) eV, respectively. These values are consistent with those calculated in. Here our investigation, using the recent complex angular momentum methodology wherein is embedded the crucial electron-electron correlations and the vital core polarization interaction, has found that the near threshold electron-Os elastic scattering total cross section (TCS) is characterized by three stable bound states of the Os- ion formed as resonances during the slow electron collision, with BEs of 1.910 eV, 1.230 eV and 0.224 eV. The new extracted electron affinity (EA) value from the TCS of 1.910 eV for the Os atom is significantly different from that measured in. Our calculated elastic differential cross sections (DCSs) also yield the relevant BEs for the ground and the two excited states of the Os- ion. The complex characteristic resonance structure in the TCS for the Os atom is ideal for catalysis, but makes it difficult to execute the Wigner threshold law in describing the threshold detachment behavior of complex atoms and extracting the reliable attendant EAs. Supported by U.S. DOE, AFOSR and CAU CFNM, NSF-CREST Program.
NASA Astrophysics Data System (ADS)
Ahmed, S. A.; Hassebo, Y. Y.; Gross, B.; Oo, M.; Moshary, F.
2006-09-01
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 polarization selective lidar receiver is aligned to minimize detected skylight, while the polarization of the transmitted lidar signal is rotated to maintain maximum lidar backscatter signal throughput to the receiver detector, consequently maximizing detected signal to noise ratio. Results presented include lidar elastic backscatter measurements, at 532 nm which show as much as a factor of ?10 improvement in signal-to-noise ratio over conventional un-polarized schemes. For vertically pointing lidars, the largest improvements are limited to symmetric early morning and late afternoon hours. For non-vertical scanning lidars, significant improvements are achievable over much more extended time periods, depending on the specific angle between the lidar and solar axes. A theoretical model that simulates the background skylight within the single scattering approximation showed good agreement with measured SNR improvement factors. Diurnally asymmetric improvement factors, sometimes observed, are explained by measured increases in PWV and subsequent modification of aerosol optical depth by dehydration from morning to afternoon. Finally, since the polarization axis follows the solar azimuth angle even for high aerosol loading, as demonstrated using radiative transfer simulations, it is possible to conceive automation of the technique. In addition, it is shown that while multiple scattering reduces the SNR improvement, the orientation of the minimum noise state remains the same.
NASA Astrophysics Data System (ADS)
Winter, Thomas
2015-05-01
Coupled-state differential cross sections are being determined for electron transfer, excitation, and elastic scattering in collisions between keV-energy protons and He+ ions. Integrated cross sections for these and other collisions were recently reported. Some differential cross sections were previously considered with smaller Sturmian bases as well as triple-center bases using an eikonal approach. The impact parameter ? is now expressed in terms of the scattering angle for potential scattering with an impact-parameter-dependent effective nuclear charge corresponding to partial screening by an electron in the He+ ground state. Integrating over the scattering angle, this formal transformation does yield the same total cross sections for excitation and electron transfer as when integrating directly over ?. Differential cross sections obtained in this way are likely to be valid at least for elastic scattering when this is the dominant channel.
Elastic Energy Storage and Radial Forces in the Myofilament Lattice Depend on Sarcomere Length
Williams, C. David; Regnier, Michael; Daniel, Thomas L.
2012-01-01
We most often consider muscle as a motor generating force in the direction of shortening, but less often consider its roles as a spring or a brake. Here we develop a fully three-dimensional spatially explicit model of muscle to isolate the locations of forces and energies that are difficult to separate experimentally. We show the strain energy in the thick and thin filaments is less than one third the strain energy in attached cross-bridges. This result suggests the cross-bridges act as springs, storing energy within muscle in addition to generating the force which powers muscle. Comparing model estimates of energy consumed to elastic energy stored, we show that the ratio of these two properties changes with sarcomere length. The model predicts storage of a greater fraction of energy at short sarcomere lengths, suggesting a mechanism by which muscle function shifts as force production declines, from motor to spring. Additionally, we investigate the force that muscle produces in the radial or transverse direction, orthogonal to the direction of shortening. We confirm prior experimental estimates that place radial forces on the same order of magnitude as axial forces, although we find that radial forces and axial forces vary differently with changes in sarcomere length. PMID:23166482
Sub-wavelength energy trapping of elastic waves in a metamaterial.
Colombi, Andrea; Roux, Philippe; Rupin, Matthieu
2014-08-01
Deep sub-wavelength focusing has been demonstrated for locally resonant metamaterials using electromagnetic and acoustic waves. The elastic equivalents of such objects are made of sub-wavelength resonating beams fixed to a two-dimensional plate, as presented here. Independent of a random or regular arrangement of the resonators, the metamaterial shows large bandgaps that are independent of the incident wave direction. Numerical simulations demonstrate that the insertion of a defect in the layout, as a shorter resonator, creates strong amplification of the wave-field on the defect. This energy trapping, which is localized on a spatial scale that is much smaller than the wavelength in the two-dimensional plate, leads to a >1 factor in terms of the local density of energy. PMID:25096146
Cross sections for elastic electron scattering by tetramethylsilane in the intermediate-energy range
NASA Astrophysics Data System (ADS)
Sugohara, R. T.; Lee, M.-T.; de Souza, G. L. C.; Homem, M. G. P.; Iga, I.
2011-12-01
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.
Low-energy elastic electron scattering from isobutanol and related alkyl amines
NASA Astrophysics Data System (ADS)
Fedus, Kamil; Navarro, C.; Hargreaves, L. R.; Khakoo, M. A.; Silva, F. M.; Bettega, M. H. F.; Winstead, C.; McKoy, V.
2014-09-01
Normalized experimental differential and integral cross sections for vibrationally elastic scattering of low-energy electrons from isobutanol (C4H9OH ) are presented. The differential cross sections are measured at incident energies from 1 to 100 eV and scattering angles from 5? to 130?. These cross sections are compared to earlier experimental and theoretical results for isobutanol and n-butanol, as well as to results for smaller alcohols and for alkanes. Further comparisons are made with calculated cross sections for isobutylamine (C4H9NH2) and for smaller amines, including ethylamine (C2H5NH2), dimethylamine (CH3NHCH3), the two C3H7NH2 isomers n-propylamine and isopropylamine, and ethylene diamine (NH2C2H4NH2). The calculated cross sections are obtained using the Schwinger multichannel method. The comparisons illuminate the role of molecular structure in determining the angular distribution of resonantly scattered electrons.
Elastic scattering of low-energy electrons by CH3CN and CH3NC molecules
NASA Astrophysics Data System (ADS)
Fujimoto, Milton M.; de Lima, Erik V. R.; Tennyson, Jonathan
2015-06-01
Rotationally-summed elastic cross sections for electrons collisions with the isomers acetonitrile and methyl isocyanide are reported. Theoretical differential and integral cross sections are calculated using the UK molecular R-matrix codes in the energy range from 1 eV to 10 eV. The dynamic interaction is represented within a static-exchange plus polarization model based on the use of an extensive orbital sets. Both molecule have a large permanent dipole moment and a Born closure procedure is used to get more reliable cross sections. These molecules show low-energy, ? ? resonances at 2.4 and 2.7 eV for CH3CN and CH3NC, respectively; and very broad ? ? ones at about 6 eV. Our results suggest that electron collisions with CH3CN / CH3NC show similar properties to those found for electron collisions with HCN / HNC.
Experimental study of energy accumulation and dissipation in iron in an elastic-plastic transition
NASA Astrophysics Data System (ADS)
Plekhov, O. A.; Saintier, N.; Naimark, O.
2007-09-01
Modern experimental studies of the temperature evolution at the surface of plastically deformed metals show that processes of energy accumulation and dissipation in the material are nonlinear even in the quasi-static case and obviously depend on the loading conditions as well as past history of deformation. Considerable intensification of investigations in this field, which has been observed during the last decade, is due to the fact that this class of problems has wide application apart from its fundamental importance. High-sensitivity IR detectors used in such experiments make it possible to develop new effective methods of nondestructive control, which are based on analysis of thermal precursors of deformation localization and failure. In this study, the features of propagation of thermal waves on the surface of pure iron under an elastic-plastic transition are investigated and time dependences of energy accumulation rate are obtained during quasi-static deformation.
Cross sections for elastic electron scattering by tetramethylsilane in the intermediate-energy range
Sugohara, R. T. [Departamento de Fisica, UFSCar, 13565-905 Sao Carlos, SP (Brazil); Lee, M.-T.; Iga, I. [Departamento de Quimica, UFSCar, 13565-905 Sao Carlos, SP (Brazil); Souza, G. L. C. de [Instituto de Ciencias Exatas e Tecnologia, UFAM, 69100-000 Itacoatiara, AM (Brazil); Homem, M. G. P. [Departamento de Fisica, UFSC, 88010-970 Florianopolis, SC (Brazil)
2011-12-15
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{sup -}-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.
Transformation Ray Method: Controlling High Frequency Elastic Waves
Chang, Zheng; Liu, Xiaoning; Hu, Gengkai
2011-01-01
A transformation method based on elastic ray theory is proposed to control high frequency elastic waves. We show that ray path can be controlled in an exact manner, however energy distribution along the ray is only approximately controlled. A numerical example of an elastic rotator is provided to illustrate the method and to access the approximation. The proposed theory may be found potential applications in seismic wave protection and structure health monitoring.
Chen, Krishichayan X.; Lui, Y. -W; Button, J.; Youngblood, David H.
2010-01-01
Elastic and inelastic scattering of 240-MeV (6)Li particles from (40)Ca and (48)Ca were measured with the multipole-dipole-multipole spectrometer from 4 degrees <= theta(c.m.) <= 40 degrees. Optical potential parameters were obtained by fitting...
Potential energy savings from aquifer thermal energy storage
Anderson, M.R.; Weijo, R.O.
1988-07-01
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.
Crystallography and elastic energy analysis of VN precipitates in Fe-Mn-Si-Cr shape memory alloys
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
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.
Shape derivative of the energy functional in a problem for a thin rigid inclusion in an elastic body
NASA Astrophysics Data System (ADS)
Rudoy, E. M.
2015-08-01
The equilibrium problem of the elastic body with a delaminated thin rigid inclusion is considered. In this case, there is a crack between the rigid inclusion and the elastic body. We suppose that the nonpenetration conditions are prescribed on the crack faces. We study the dependence of the energy of the body on domain variations. The formula for the shape derivative of the energy functional is obtained. Moreover, it is shown that for the special cases of the domain perturbations such derivative can be represented as invariant integrals.
Jose Manuel Romero-Enrique; Chi-Tuong Pham; Pedro Patricio
2010-06-23
We characterize the elastic contribution to the surface free energy of a nematic in presence of a sawtooth substrate. Our findings are based on numerical minimization of the Landau-de Gennes model and analytical calculations on the Frank-Oseen theory. The nucleation of disclination lines (characterized by non-half-integer winding numbers) in the wedges and apexes of the substrate induces a leading order proportional to qlnq to the elastic contribution to the surface free energy density, q being the wavenumber associated with the substrate periodicity.
Romero-Enrique, Jose Manuel; Pham, Chi-Tuong; Patrício, Pedro
2010-07-01
We characterize the elastic contribution to the surface free energy of a nematic liquid crystal in the presence of a sawtooth substrate. Our findings are based on numerical minimization of the Landau-de Gennes model and analytical calculations on the Frank-Oseen theory. The nucleation of disclination lines (characterized by non-half-integer winding numbers) in the wedges and apexes of the substrate induces a leading order proportional to q ln q to the elastic contribution to the surface free-energy density, with q being the wave number associated with the substrate periodicity. PMID:20866635
Krishichayan,; Chen, X.; Lui, Y.-W.; Button, J.; Youngblood, D. H. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)
2010-04-15
Elastic and inelastic scattering of 240-MeV {sup 6}Li particles from {sup 40}Ca and {sup 48}Ca were measured with the multipole-dipole-multipole spectrometer from 4 deg. <=theta{sub c.m.}<=40 deg. Optical potential parameters were obtained by fitting the elastic-scattering data with the double-folding model using the density-dependent M3Y NN effective interaction and B(E2) and B(E3) values obtained for low-lying 2{sup +} and 3{sup -} states agreed with the adopted values. The results are compared with those obtained using potentials derived from the systematics of potentials previously obtained for {sup 24}Mg, {sup 28}Si, {sup 58}Ni, and {sup 90}Zr. Cross sections for excitation of giant resonances were also calculated with the potentials obtained.
Cogeneration potential of energy conversion systems
Brown, D.H.
1982-08-01
Energy conversion systems for industrial cogeneration, supplying both electricity and process heat, were characterized in order to match each candidate to specific industrial requirements. The ratio of power to process heat is shown to be a critical factor in achieving matches that produce appreciable fuel savings. Economic screening, based on return on incremental investment, further refines the selection. The potential national fuel savings in 1990 are developed for the energy conversion systems with the greatest impact at levels of 0% and a 20% return on investment.
Computed potential energy surfaces for chemical reactions
NASA Technical Reports Server (NTRS)
Walch, Stephen P.
1994-01-01
Quantum mechanical methods have been used to compute potential energy surfaces for chemical reactions. The reactions studied were among those believed to be important to the NASP and HSR programs and included the recombination of two H atoms with several different third bodies; the reactions in the thermal Zeldovich mechanism; the reactions of H atom with O2, N2, and NO; reactions involved in the thermal De-NO(x) process; and the reaction of CH(squared Pi) with N2 (leading to 'prompt NO'). These potential energy surfaces have been used to compute reaction rate constants and rates of unimolecular decomposition. An additional application was the calculation of transport properties of gases using a semiclassical approximation (and in the case of interactions involving hydrogen inclusion of quantum mechanical effects).
Determining Equilibrium Structures and Potential Energy Functions for
Le Roy, Robert J.
Chapter 6 Determining Equilibrium Structures and Potential Energy Functions for Diatomic Molecules also to determine accurate potential energy functions spanning the whole potential energy well to that in the published version of this chapter. 159 #12;determine the potential energy function as an array of points
Convective Available Potential Energy of World Ocean
NASA Astrophysics Data System (ADS)
Su, Z.; Ingersoll, A. P.; Thompson, A. F.
2012-12-01
Here, for the first time, we propose the concept of Ocean Convective Available Potential Energy (OCAPE), which is the maximum kinetic energy (KE) per unit seawater mass achievable by ocean convection. OCAPE occurs through a different mechanism from atmospheric CAPE, and involves the interplay of temperature and salinity on the equation of state of seawater. The thermobaric effect, which arises because the thermal coefficient of expansion increases with depth, is an important ingredient of OCAPE. We develop an accurate algorithm to calculate the OCAPE for a given temperature and salinity profile. We then validate our calculation of OCAPE by comparing it with the conversion of OCAPE to KE in a 2-D numerical model. We propose that OCAPE is an important energy source of ocean deep convection and contributes to deep water formation. OCAPE, like Atmospheric CAPE, can help predict deep convection and may also provide a useful constraint for modelling deep convection in ocean GCMs. We plot the global distribution of OCAPE using data from the World Ocean Atlas 2009 (WOA09) and see many important features. These include large values of OCAPE in the Labrador, Greenland, Weddell and Mediterranean Seas, which are consistent with our present observations and understanding, but also identify some new features like the OCAPE pattern in the Antarctic Circumpolar Current (ACC). We propose that the diagnosis of OCAPE can improve our understanding of global patterns of ocean convection and deep water formation as well as ocean stratification, the meridional overturning circulation and mixed layer processes. The background of this work is briefly introduced as below. Open-ocean deep convection can significantly modify water properties both at the ocean surface and throughout the water column (Gordon 1982). Open-ocean convection is also an important mechanism for Ocean Deep Water formation and the transport of heat, freshwater and nutrient (Marshall and Schott 1999). Open-ocean convection may arise through strong surface buoyancy fluxes (Schott et al. 1996), or by thermobaric instability (Akitomo 1999a, b). Ingersoll (2005) demonstrated that thermobaric-induced deep convection is due to the abrupt release of ocean potential energy into kinetic energy. In atmospheric dynamics, Convective Available Potential Energy (CAPE) has long been an important thermodynamic variable (Arakawa and Schubert 1974) that has been used to forecast moist convection (Doswell and Rasmussen 1994) and to test the performance of GCMs (Ye et al. 1998). However, the development of a similar diagnostic in the ocean has received little attention.; World Ocean Convective Available Potential Energy distribution in North-Hemisphere Autumn (J/kg)
Potential Fluctuation Equality for Free Energy Evaluation
Ngo, Van
2011-01-01
Jarzynski's equality [1] allows us to investigate free energy landscapes (FELs) by constructing distributions of work performed on a system from an initial ensemble of states to final states. This work is experimentally measured by extension-versus-force (EVF) curves. We proposed a new approach that enables us to reconstruct such FELs without necessity of measuring EVF curves. We proved that any free energy changes could be computed by measuring the fluctuations of a harmonic external potential in final states. The main assumption of our proof is that one should probably treat a potential's minimum {\\lambda} (thought to be control parameter) and time in separate and independent manners. We recovered Jarzynski's equality from the introduction of a double Heaviside function. We then applied the approach in molecular dynamics (MD) simulations to compute the free energy barrier of breaking DNA base pairs (bps). The free energy barrier for breaking a CG bp in our simulations is identified as 1.7 +/- 0.2 kcal/mol t...
NASA Astrophysics Data System (ADS)
Ayabakan, M.; Faubel, M.; Martínez-Haya, B.; Rusin, L. Yu.; Sevryuk, M. B.; Tappe, U.; Toennies, J. P.
1998-03-01
The F+D 2 elastic scattering as well as the D 2( ji=0 ? jf=2), D 2( ji=1 ? jf=3) and, for the first time, D 2( ji=0 ? jf=4) inelastic rotational transitions have been measured in a crossed molecular beam experiment at a center-of-mass collision energy of 112±2 meV. Differential cross-sections for the measured rotational transitions have been calculated on three different potential energy surfaces (Takayanagi-Sato, DMBE-6SEC of Truhlar and coworkers, and Stark-Werner) using different quasiclassical and semiclassical techniques. Although an overall qualitative agreement is found between the experimental and computed differential cross-sections, significant discrepancies are also apparent. In particular, the dynamical calculations lead to a systematic underestimation of the scattering yield into the non-reactive scattering channels, which can be attributed to shortcomings in the topography of all the three surfaces probed. Replacing the free deuterium molecule with a rigid or a vibrating rotor (both of these models exclude reaction) in the dynamical treatment considerably reduces the disagreement between the experimental and the calculated differential cross-sections for the different inelastic transitions.
Antihydrogen-hydrogen elastic scattering at thermal energies using an atomic-orbital technique
Sinha, Prabal K.; Chaudhuri, Puspitapallab; Ghosh, A.S. [Department of Physics, Bangabasi College, 19, Raj Kumar Chakravorty Sarani, Kolkata 700 009 (India); Instituto de Fisica 'Gleb Wataghin', Universidade Estadual de Campinas, 13083-970 Campinas, Sao Paulo (Brazil); Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)
2003-05-01
In view of the recent interest in the trapping of antihydrogen atom H(bar sign), at very low temperatures, H-bar-H scattering has been investigated at low incident energies using a close-coupling model with the basis set H-bar(1s,2s,2p-bar)+H(1s,2s,2p-bar). The predicted s-wave elastic phase shifts, scattering length, and effective range are in a good agreement with the other recent predictions of Jonsell et al. and of Armour and Chamberlain. The results indicate that the atomic orbital expansion model is suitable to study the H-bar-H scattering at ultracold temperatures.
Enhanced piezoelectric energy harvesting of a bistable oscillator with an elastic magnifier
NASA Astrophysics Data System (ADS)
Wang, Guang Qing; Liao, Wei-Hsin
2015-04-01
This paper presents theoretical investigation on a coupling system consisting of bistable oscillator with an elastic magnifier (EM) to improve the output performances in vibration energy harvesting. Lumped-parameter nonlinear equations of the coupling system are derived to describe the broadband large-amplitude periodic displacement responses of the coupling system. The effects of the system mass ratio and stiffness ration on the output performances are studied. It shows that increasing the mass ratio and stiffness ratio can improve the system output performances. The distinct advantage in the coupling system lies in the existence of large-orbit periodic vibration over low level range. With the comparison of the electromechanical trajectories obtained from simulations, it shows that the coupling system can harvest more power at low excitation level with larger bandwidth as compared to the bistable oscillator without an EM.
L. V. Elnikova
2014-10-09
In nematic liquid crystals (NLCs), topological defects of a chiral origin play a role in phase transitions and lead to phase configurations of nontrivial topology, like those in neutron stars and helium in the A-phase. In the biaxial-uniaxial phase transition, the deformation of the orbit, as the order parameter degeneracy of the NLC, connects together an evolution of topological defects, the surface anchoring energy and elastic Frank modui. In this work we estimate the chiral gauge field presentation of the constrained Ladnau-de Gennes theory of the biaxial nematics, which have to explain their topologically dependent phase transformation, using the description of the transformation of disclinations in the biaxial nematic phase into the surface bojooms of a uniaxial NLC.
Elastic scattering of low-energy electrons by 1,4-dioxane
Barbosa, Alessandra Souza; Bettega, Márcio H. F.
2014-05-14
We report calculated cross sections for elastic collisions of low-energy-electrons with 1,4-dioxane. Our calculations employed the Schwinger multichannel method with pseudopotentials and were carried out in the static-exchange and static-exchange plus polarization approximations for energies up to 30 eV. Our results show the presence of three shape resonances belonging to the B{sub u}, A{sub u}, and B{sub g} symmetries and located at 7.0 eV, 8.4 eV, and 9.8 eV, respectively. We also report the presence of a Ramsauer-Townsend minimum located at around 0.05 eV. We compare our calculated cross sections with experimental data and R-matrix and independent atom model along with the additivity rule corrected by using screening coefficients theoretical results for 1,4-dioxane obtained by Palihawadana et al. [J. Chem. Phys. 139, 014308 (2013)]. The agreement between the present and the R-matrix theoretical calculations of Palihawadana et al. is relatively good at energies below 10 eV. Our calculated differential cross sections agree well with the experimental data, showing only some discrepancies at higher energies.
Touchette, Brant W.; Marcus, Sarah E.; Adams, Emily C.
2014-01-01
Bulk modulus of elasticity (?), depicting the flexibility of plant tissues, is recognized as an important component in maintaining internal water balance. Elevated ? and comparatively low osmotic potential (??) may work in concert to effectively maintain vital cellular water content. This concept, termed the ‘cell water conservation hypothesis’, may foster tolerance for lower soil-water potentials in plants while minimizing cell dehydration and shrinkage. Therefore, the accumulation of solutes in marine plants, causing decreases in ??, play an important role in plant–water relations and likely works with higher ? to achieve favourable cell volumes. While it is generally held that plants residing in marine systems have higher leaf tissue ?, to our knowledge no study has specifically addressed this notion in aquatic and wetland plants residing in marine and freshwater systems. Therefore, we compared ? and ?? in leaf tissues of 38 freshwater, coastal and marine plant species using data collected in our laboratory, with additional values from the literature. Overall, 8 of the 10 highest ? values were observed in marine plants, and 20 of the lowest 25 ? values were recorded in freshwater plants. As expected, marine plants often had lower ??, wherein the majority of marine plants were below ?1.0 MPa and the majority of freshwater plants were above ?1.0 MPa. While there were no differences among habitat type and symplastic water content (?sym), we did observe higher ?sym in shrubs when compared with graminoids, and believe that the comparatively low ?sym observed in aquatic grasses may be attributed to their tendency to develop aerenchyma that hold apoplastic water. These results, with few exceptions, support the premise that leaf tissues of plants acclimated to marine environments tend to have higher ? and lower ??, and agree with the general tenets of the cell water conservation hypothesis. PMID:24876296
A. Nadasen; M. McMaster; M. Fingal; J. Tavormina; P. Schwandt; J. S. Winfield; M. F. Mohar; F. D. Becchetti; J. W. Jaenecke; R. E. Warner
1989-01-01
Differential cross sections for the elastic scattering of â¶Li ions have been measured at a bombarding energy of 210 MeV. Angular distributions for Â²â¸Si (3.6Â°--45.9Â°), â´Â°Ca (4.6Â°--43.5Â°), and â¹Â°Zr (4.0Â°--43.6Â°) extend sufficiently into the rainbow region to enable the extraction of unique â¶Li potentials. For the Â²Â°â¸Pb target (3.1Â°--36.0Â°), Coulomb scattering dominates with only a slight evidence of nuclear diffraction
Precision Pion-Proton Elastic Differential Cross Sections at Energies Spanning the Delta Resonance
M. M. Pavan; J. T. Brack; F. Duncan; A. Feltham; G. Jones; J. Lange; K. J. Raywood; M. E. Sevior; R. Adams; D. F. Ottewell; G. R. Smith; B. Wells; R. L. Helmer; E. L. Mathie; R. Tacik; R. A. Ristinen; I. I. Strakovsky; H-M. Staudenmaier
2001-03-15
A precision measurement of absolute pi+p and pi-p elastic differential cross sections at incident pion laboratory kinetic energies from T_pi= 141.15 to 267.3 MeV is described. Data were obtained detecting the scattered pion and recoil proton in coincidence at 12 laboratory pion angles from 55 to 155 degrees for pi+p, and six angles from 60 to 155 degrees for pi-p. Single arm measurements were also obtained for pi+p energies up to 218.1 MeV, with the scattered pi+ detected at six angles from 20 to 70 degrees. A flat-walled, super-cooled liquid hydrogen target as well as solid CH2 targets were used. The data are characterized by small uncertainties, ~1-2% statistical and ~1-1.5% normalization. The reliability of the cross section results was ensured by carrying out the measurements under a variety of experimental conditions to identify and quantify the sources of instrumental uncertainty. Our lowest and highest energy data are consistent with overlapping results from TRIUMF and LAMPF. In general, the Virginia Polytechnic Institute SM95 partial wave analysis solution describes our data well, but the older Karlsruhe-Helsinki PWA solution KH80 does not.
NASA Astrophysics Data System (ADS)
Hamacher, Kay
2011-07-01
Biomolecular simulations have become a major tool in understanding biomolecules and their complexes. However, one can typically only investigate a few mutants or scenarios due to the severe computational demands of such simulations, leading to a great interest in method development to overcome this restriction. One way to achieve this is to reduce the complexity of the systems by an approximation of the forces acting upon the constituents of the molecule. The harmonic approximation used in elastic network models simplifies the physical complexity to the most reduced dynamics of these molecular systems. The reduced polymer modeled this way is typically comprised of mass points representing coarse-grained versions of, e.g., amino acids. In this work, we show how the computation of free energy contributions of contacts between two residues within the molecule can be reduced to a simple lookup operation in a precomputable matrix. Being able to compute such contributions is of great importance: protein design or molecular evolution changes introduce perturbations to these pair interactions, so we need to understand their impact. Perturbation to the interactions occurs due to randomized and fixated changes (in molecular evolution) or designed modifications of the protein structures (in bioengineering). These perturbations are modifications in the topology and the strength of the interactions modeled by the elastic network models. We apply the new algorithm to (1) the bovine trypsin inhibitor, a well-known enzyme in biomedicine, and show the connection to folding properties and the hydrophobic collapse hypothesis and (2) the serine proteinase inhibitor CI-2 and show the correlation to ? values to characterize folding importance. Furthermore, we discuss the computational complexity and show empirical results for the average case, sampled over a library of 77 structurally diverse proteins. We found a relative speedup of up to 10 000-fold for large proteins with respect to repeated application of the initial model.
Optimizing energy potentials for success in protein tertiary structure prediction
Goldstein, Richard
Optimizing energy potentials for success in protein tertiary structure prediction Ting-Lan Chiu1 on the choice of an accurate potential energy function. For a single protein sequence, it has been shown that the potential energy function can be optimized for predictive success by maximizing the energy gap between
California's biomass and its energy potential
Lucarelli, F.B. Jr.
1980-04-01
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.
Metabolic energy cost of action potential velocity.
Crotty, Patrick; Sangrey, Thomas; Levy, William B
2006-09-01
The action potential of the unmyelinated nerve is metabolically expensive. Using the energetic cost per unit length for the biophysically modeled action potential of the squid giant axon, we analyze this cost and identify one possible optimization. The energetic cost arising from an action potential is divided into three separate components: 1) the depolarization of the rising phase; 2) the hyperpolarization of the falling phase; and 3) the largest component, the overlapping of positive and negative currents, which has no electrical effect. Using both the Hodgkin-Huxley (HH) model and an improved version of the HH model (HHSFL), we investigate the variation of these three components as a function of easily evolvable parameters, axon diameter and ion channel densities. Assuming conduction velocity is well designed for each organism, the energy component associated with the rising phase attains a minimum near the biological values of the diameter and channel densities. This optimization is explained by the membrane capacitance per unit length. The functional capacitance is the sum of the intrinsic membrane capacitance and the gating capacitance associated with the sodium channel, and this capacitance minimizes at nearly the same values of diameter and channel density. Because capacitance is temperature independent and because this result is independent of the assumed velocity, the result generalizes to unmyelinated mammalian axons. That is, channel density is arguably an evolved property that goes hand-in-hand with the evolutionary stability of the sodium channel. PMID:16554507
Yuri Kamyshkov; Jeffrey Tithof; Mikhail Vysotsky
2008-11-25
We found that spin-one new light particle exchanges are strongly bounded by high-energy and small momentum transfer np elastic scattering data; the analogous bound for a scalar particle is considerably weaker, while for a pseudoscalar particle no bounds can be set. These bounds are compared with the bounds extracted from low-energy n-Pb scattering experiments and from the bounds of pi0 and K+ meson decays.
Kamyshkov, Yuri; Tithof, Jeffrey; Vysotsky, Mikhail [University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); ITEP, Moscow, 117218 (Russian Federation)
2008-12-01
We found that spin-one new light particle exchanges are strongly bounded by high-energy and small momentum transfer np elastic scattering data; the analogous bound for a scalar particle is considerably weaker, while for a pseudoscalar particle no bounds can be set. These bounds are compared with the bounds extracted from low-energy n-Pb scattering experiments and from the bounds of {pi}{sup 0} and K{sup +} meson decays.
Ocean Thermal Energy Conversion: Potential Environmental Impacts and Fisheries
Hawai'i at Manoa, University of
Ocean Thermal Energy Conversion: Potential Environmental Impacts and Fisheries Christina M Comfort Institute #12;Ocean Thermal Energy Conversion (OTEC) · Renewable energy ocean thermal gradient · Large, M.Sc. Candidate University of Hawaii at Manoa Department of Oceanography Hawaii Natural Energy
Elastic free-energy of wormlike micellar chains: theory and suggested experiments
Meisam Asgari
2015-02-09
The extensive application of surfactants motivates comprehensive and predictive theoretical studies that improve our understanding of the behaviour of these complex systems. In this study, an expression for the elastic free-energy density of a wormlike micellar chain is derived taking into account interactions between its constituent molecules. The resulting expression incorporates the sum of a quadratic term in the curvature and a quadratic term in the torsion of the centerline of wormlike micelle and thus resembles free-energy density functions for polymer chains and DNA available in the literature. The derived model is applied on a wormlike micelle in the shape of a circular arc, open or closed. A detailed application of the derived model on wormlike micelles of toroidal shape, along with employing necessary statistical-thermodynamical concepts of self-assembly, is performed, and the results are found to be consistent with the ones available in the literature. Steps towards obtaining the material parameters through experiments are suggested and discussed.
Determination of solid material elastic modulus and surface energy based on JKR contact model
NASA Astrophysics Data System (ADS)
Wu, Kuang-Chung; You, Hsien-I.
2007-08-01
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.
Energy potential of sugarcane and sweet sorghum
Elawad, S.H.; Gascho, G.J.; Shih, S.F.
1980-01-01
The potential of sugarcane and sweet sorghum as raw materials for the production of ethanol and petrochemical substitutes is discussed. Both crops belong to the grass family and are classified as C/sub 4/ malateformers which have the highest rate of photosynthesis among terrestrial plants. Large amounts of biomass are required to supply a significant fraction of US energy consumption. Biomass production could be substantially increased by including tops and leaves, adopting narrow row spacing and improving cultural practices. This presents challenges for cultivating, harvesting, and hauling the biomass to processing centers. Large plants and heavy capital investment are essential for energy production. Ethanol and ammonia are the most promising candidates of a biomass program. If sugarcane were to be used for biomass production, breeding programs should be directed for more fermentable sugars and fiber. Energy research on sweet sorghum should be done with syrup varieties. Sweet sorghum needs to be incorporated with other crops because of its short growing season. The disposal of stillage from an extensive ethanol industry may pose environmental problems.
Three-phase plane composites of minimal elastic stress energy: High-porosity structures
Andrej Cherkaev; Grzegorz Dzierzanowski
2013-08-14
The paper establishes exact lower bound on the effective elastic energy of two-dimensional, three-material composite subjected to the homogeneous, anisotropic stress. It is assumed that the materials are mixed with given volume fractions and that one of the phases is degenerated to void, i.e. the effective composite is porous. Explicit formula for the energy bound is obtained using the translation method enhanced with additional inequality expressing certain property of stresses. Sufficient optimality conditions of the energy bound are used to set the requirements which have to be met by the stress fields in each phase of optimal effective material regardless of the complexity of its microstructural geometry. We show that these requirements are fulfilled in a special class of microgeometries, so-called laminates of a rank. Their optimality is elaborated in detail for structures with significant amount of void, also referred to as high-porosity structures. It is shown that geometrical parameters of optimal multi-rank, high-porosity laminates are different in various ranges of volume fractions and anisotropy level of external stress. Non-laminate, three-phase microstructures introduced by other authors and their optimality in high-porosity regions is also discussed by means of the sufficient conditions technique. Conjectures regarding low-porosity regions are presented, but full treatment of this issue is postponed to a separate publication. The corresponding "G-closure problem" of a three-phase isotropic composite is also addressed and exact bounds on effective isotropic properties are explicitly determined in these regions where the stress energy bound is optimal.
Spectroscopy of reactive potential energy surfaces Daniel M. Neumark
Neumark, Daniel M.
Spectroscopy of reactive potential energy surfaces Daniel M. Neumark Department of Chemistry spectroscopy rather than scattering is used to probe reactive potential energy surfaces. The application of negative ion photodetachment to the transition state spectroscopy of benchmark reactions is described
Development of the Potential Energy Savings Estimation (PESE) Toolkit
Liu, J.; Baltazar, J. C.; Claridge, D. E.
2010-01-01
This study has developed a prototype computer tool called the Potential Energy Savings Estimation (PESE) Toolkit. Baltazar’s methodology for potential energy savings estimation from EBCx/retrofit measures has been improved ...
Induced Seismicity Potential of Energy Technologies
NASA Astrophysics Data System (ADS)
Hitzman, Murray
2013-03-01
Earthquakes attributable to human activities-``induced seismic events''-have received heightened public attention in the United States over the past several years. Upon request from the U.S. Congress and the Department of Energy, the National Research Council was asked to assemble a committee of experts to examine the scale, scope, and consequences of seismicity induced during fluid injection and withdrawal associated with geothermal energy development, oil and gas development, and carbon capture and storage (CCS). The committee's report, publicly released in June 2012, indicates that induced seismicity associated with fluid injection or withdrawal is caused in most cases by change in pore fluid pressure and/or change in stress in the subsurface in the presence of faults with specific properties and orientations and a critical state of stress in the rocks. The factor that appears to have the most direct consequence in regard to induced seismicity is the net fluid balance (total balance of fluid introduced into or removed from the subsurface). Energy technology projects that are designed to maintain a balance between the amount of fluid being injected and withdrawn, such as most oil and gas development projects, appear to produce fewer seismic events than projects that do not maintain fluid balance. Major findings from the study include: (1) as presently implemented, the process of hydraulic fracturing for shale gas recovery does not pose a high risk for inducing felt seismic events; (2) injection for disposal of waste water derived from energy technologies does pose some risk for induced seismicity, but very few events have been documented over the past several decades relative to the large number of disposal wells in operation; and (3) CCS, due to the large net volumes of injected fluids suggested for future large-scale carbon storage projects, may have potential for inducing larger seismic events.
An ab initio method for locating potential energy minima
Bock, Nicolas; Peery, Travis; Venneri, Giulia; Chisolm, Eric; Wallace, Duane; Lizarraga, Raquel; Holmstrom, Erik
2009-01-01
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.
Perturbed nutations, Love numbers and elastic energy of deformation for Earth models 1066A and 1066B
Juan Getino
1993-01-01
In this paper, the integration method of Takeuchi (1950) is applied to Gilbert and Dziewonski Earth Models1066A and1066B, with the aim of obtaining the functionsFnGn andKn that make up the expression of the displacement vector for the Earth's elastic mantle. The procedure of this integration is valid for any ordern of the perturbing potential expansion in spherical harmonics. The values
Energy resource potential of natural gas hydrates
Collett, T.S.
2002-01-01
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.
Recto Running Head 1 Available Potential Energy and Exergy in
Tailleux, Remi
Recto Running Head 1 Available Potential Energy and Exergy in Stratified Fluids R´emi Tailleux, thermodynamic efficiencies, buoyancy forcing. Abstract Lorenz's theory of available potential energy (APE minimises potential energy at constant entropy. This review seeks to shed light on the two concepts
An Adaptive Treecode for Computing Nonbonded Potential Energy in
Krasny, Robert
An Adaptive Treecode for Computing Nonbonded Potential Energy in Classical Molecular Systems ZHONG computation of the nonbonded potential energy in classical molecular systems. The algorithm treats a general 22: 184Â195, 2001 Keywords: adaptive treecode; nonbonded potential energy; classical molecular system
Regularization properties for Minimal Geodesics of a Potential Energy
Kimmel, Ron
Regularization properties for Minimal Geodesics of a Potential Energy Laurent COHEN 1 and Ron the ``snake'' energy by including the internal regularization term in the external potential term. Our method among all paths joining two endpoints. We show that our energy, though only based on a potential
Nov. 30, 2010 Potential Energy Surfaces for Simulating Complex Chemical
Truhlar, Donald G
Nov. 30, 2010 Potential Energy Surfaces for Simulating Complex Chemical Processes On Nov. 30, 2010 calculations. The Truhlar group will look at potential energy surfaces for simulating complex chemical will provide potential energy surfaces and force fields for simulating these complex chemical processes
Thermophotovoltaic energy conversion: Technology and market potential
NASA Astrophysics Data System (ADS)
Ostrowski, Leon J.; Pernisz, Udo C.; Fraas, Lewis M.
1996-02-01
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.
The HCO?-H? van der Waals interaction: potential energy and scattering.
Massó, H; Wiesenfeld, L
2014-11-14
We compute the rigid-body, four-dimensional interaction potential between HCO(+) and H2. The ab initio energies are obtained at the coupled-cluster single double triple level of theory, corrected for Basis Set Superposition Errors. The ab initio points are fit onto the spherical basis relevant for quantum scattering. We present elastic and rotationally inelastic coupled channels scattering between low lying rotational levels of HCO(+) and para-/ortho-H2. Results are compared with similar earlier computations with He or isotropic para-H2 as the projectile. Computations agree with earlier pressure broadening measurements. PMID:25399141
Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo
Roach, Neil T.; Venkadesan, Madhusudhan; Rainbow, Michael J.; Lieberman, Daniel E.
2013-01-01
Although some primates, including chimpanzees, throw objects occasionally1,2, only humans regularly throw projectiles with high speed and great accuracy. Darwin noted that humans’ unique throwing abilities, made possible when bipedalism emancipated the arms, enabled foragers to effectively hunt using projectiles3. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence on when, how, and why hominins evolved the ability to generate high-speed throws4-8. Here, we show using experimental studies of throwers that human throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately two million years ago in the species Homo erectus. Given archaeological evidence that suggests hunting activity intensified around this time9, we conclude that selection for throwing in order to hunt likely played an important role in the evolution of the human genus. PMID:23803849
Elastic scattering of {sup 16}O+{sup 16}O at energies E/A between 5 and 8 MeV
Nicoli, M. P. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France); Haas, F. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France); Freeman, R. M. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France); Aissaoui, N. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France); Beck, C. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France); Elanique, A. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France); Nouicer, R. [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France)] [Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Universite Louis Pasteur, Boite Postale 28, F-67037 Strasbourg Cedex 2, (France); Morsad, A. [Faculte des Sciences Ben M'Sik, Universite Hassan II, Casablanca (Morocco)] [Faculte des Sciences Ben M'Sik, Universite Hassan II, Casablanca (Morocco); Szilner, S. [Ruder Boskovic Institute, Zagreb, (Croatia)] [Ruder Boskovic Institute, Zagreb, (Croatia); Basrak, Z. [Ruder Boskovic Institute, Zagreb, (Croatia)] [Ruder Boskovic Institute, Zagreb, (Croatia)
1999-12-01
The elastic scattering of {sup 16}O+{sup 16}O has been measured at nine energies between E{sub lab}=75 and 124 MeV. The data cover up to 100 degree sign in the c.m. and can be described in terms of phenomenological and folding model potentials which reproduce the main features observed. In agreement with studies at higher energies in this and similar systems, refractive effects are present in the angular distributions at all energies. In particular, the passage of Airy minima through 90 degree sign at E{sub c.m.}=40, 47.5, and 62 MeV explains the deep minima observed in the excitation function. The real part of the optical potential is found to vary very little with energy over the studied interval, but the imaginary part shows a rapid change in its shape at incident energy about 90 MeV. Nonetheless, the energy dependence of the volume integral of the real and imaginary parts is in agreement with dispersion relation predictions. (c) 1999 The American Physical Society.
Bazilevsky A.; Alekseev, I.; Aschenauer, E.; Atoyan, G.; Bravar, A.; Bunce, G.; Boyle, K.; Gill, R.; Huang, H.; Lee, S.; Makdisi, Y.; Morozov, B.; Nakagawa, I.; Okada, H.; Svirida, D.; Zelenski, A.
2010-09-27
We present new measurements of the analyzing power A{sub N} in proton-proton elastic scattering in the Coulomb-Nuclear Interference region at {radical}s = 7.7 and 21.7 GeV obtained with the polarized atomic hydrogen jet target at RHIC. These measurements complement our earlier results at {radical}s = 6.8 and 13.7 GeV confirming the presence of a hadronic helicity flip amplitude contribution in proton-proton elastic scattering at lower energies ({radical}s <8 GeV) while higher energy data ({radical}s >13 GeV) are consistent with no hadronic helicity flip contribution.
Elastic internal flywheel gimbal
Rabenhorst, D.W.
1981-01-13
An elastic joint mounting and rotatably coupling a rotary inertial energy storage device or flywheel, to a shaft, the present gimbal structure reduces vibration and shock while allowing precession of the flywheel without the need for external gimbal mounts. The present elastic joint usually takes the form of an annular elastic member either integrally formed into the flywheel as a centermost segment thereof or attached to the flywheel or flywheel hub member at the center thereof, the rotary shaft then being mounted centrally to the elastic member.
ASSESSMENT OF ENERGY RECOVERY POTENTIAL OF INDUSTRIAL COMBUSTION EQUIPMENT
An assessment was conducted to evaluate the waste heat content and energy recovery potential of flue gases from 30 industrial combustion devices. Pollution controls on nine of the devices were evaluated to estimate energy requirements and particulate reduction; energy requirement...
On the failure of hyperbolicity in elasticity
NASA Technical Reports Server (NTRS)
Zak, M.
1982-01-01
The failure of hyperbolicity leading to the instability as an ill-posedness of the Cauchy problem is investigated for elasticity. The criteria for that instability are derived in terms of the potential energy as a function of the strain invariants. The theory is illustrated by examples.
Francois Murat; Roberto Paroni
2015-02-13
We consider a sequence of linear hyper-elastic, inhomogeneous and fully anisotropic bodies in a reference configuration occupying a cylindrical region of height epsilon. We then study, by means of Gamma-convergence, the asymptotic behavior as epsilon goes to zero of the sequence of complementary energies. The limit functional is then identified as a dual problem for a two-dimensional plate. Our approach gives a direct characterization of the convergence of the equilibrating stress fields.
NASA Astrophysics Data System (ADS)
Anderson, E. K.; Boadle, R. A.; Machacek, J. R.; Chiari, L.; Makochekanwa, C.; Buckman, S. J.; Brunger, M. J.; Garcia, G.; Blanco, F.; Ingolfsson, O.; Sullivan, J. P.
2014-07-01
Measurements of the grand total and total positronium formation cross sections for positron scattering from uracil have been performed for energies between 1 and 180 eV, using a trap-based beam apparatus. Angular, quasi-elastic differential cross section measurements at 1, 3, 5, 10, and 20 eV are also presented and discussed. These measurements are compared to existing experimental results and theoretical calculations, including our own calculations using a variant of the independent atom approach.
Anderson, E K; Boadle, R A; Machacek, J R; Chiari, L; Makochekanwa, C; Buckman, S J; Brunger, M J; Garcia, G; Blanco, F; Ingolfsson, O; Sullivan, J P
2014-07-21
Measurements of the grand total and total positronium formation cross sections for positron scattering from uracil have been performed for energies between 1 and 180 eV, using a trap-based beam apparatus. Angular, quasi-elastic differential cross section measurements at 1, 3, 5, 10, and 20 eV are also presented and discussed. These measurements are compared to existing experimental results and theoretical calculations, including our own calculations using a variant of the independent atom approach. PMID:25053319
Non-contacting transfer of elastic energy into explosive simulants for dynamic property estimation
Greeney, Nathan S.; Strovink, Kurt M.; Scales, John A.; Jessop, Andrew M.; Stuart Bolton, J.; Watson, Christopher C.; Adams, Douglas E.
2014-05-21
Non-contacting acoustical methods can be used to extract various material properties of liquid or solid samples without disturbing the sample. These methods are useful even in the lab since they do not involve coupling anything to the sample, which might change its properties. A forteriori, when dealing with potentially dangerous materials, non-contacting methods may be the only safe solutions to mechanical characterization. Here, we show examples of using laser ultrasound to remotely insonify and monitor the elastic properties of several granular explosive simulants. The relatively short near-infrared laser pulse length (a few hundred nanoseconds) provides a broad-band thermoelastic source of ultrasound; we intentionally stay in the thermoelastic regime to avoid damaging the material. Then, we use a scanning laser Doppler vibrometer to measure the ultrasonic response of the sample. LDV technology is well established and very sensitive at ultrasonic frequencies; atomic level motions can be measured with modest averaging. The resulting impulse response of the explosive simulant can be analyzed to determine decay rates and wave speeds, with stiffer samples showing faster wave speeds and lower decay rates. On the other hand, at the low-frequency end of the acoustic spectrum, we use an electronically phased array to couple into a freely suspended sample's normal modes. This allows us to gently heat up the sample (3?°C in just under 5 min, as shown with a thermal IR camera). In addition to the practical interest in making the sample more chemically visible through heat, these two measurements (low-frequency resonant excitation vs high-frequency wave propagation) bracket the frequency range of acoustic non-destructive evaluation methods available.
Transportation Energy Use and Conservation Potential
ERIC Educational Resources Information Center
Hirst, Eric
1973-01-01
Analyzes transportation energy consumption and energy intensiveness for inter-city freight and passenger traffic and urban passenger traffic with the definition of energy intensiveness as Btu per ton-mile or per passenger-mile. Indicates that public education is one of three ways to achieve the goals of energy conservation. (CC)
Synergy of elastic and inelastic energy loss on ion track formation in SrTiO3
NASA Astrophysics Data System (ADS)
Weber, William J.; Zarkadoula, Eva; Pakarinen, Olli H.; Sachan, Ritesh; Chisholm, Matthew F.; Liu, Peng; Xue, Haizhou; Jin, Ke; Zhang, Yanwen
2015-01-01
While the interaction of energetic ions with solids is well known to result in inelastic energy loss to electrons and elastic energy loss to atomic nuclei in the solid, the coupled effects of these energy losses on defect production, nanostructure evolution and phase transformations in ionic and covalently bonded materials are complex and not well understood due to dependencies on electron-electron scattering processes, electron-phonon coupling, localized electronic excitations, diffusivity of charged defects, and solid-state radiolysis. Here we show that a colossal synergy occurs between inelastic energy loss and pre-existing atomic defects created by elastic energy loss in single crystal strontium titanate (SrTiO3), resulting in the formation of nanometer-sized amorphous tracks, but only in the narrow region with pre-existing defects. These defects locally decrease the electronic and atomic thermal conductivities and increase electron-phonon coupling, which locally increase the intensity of the thermal spike for each ion. This work identifies a major gap in understanding on the role of defects in electronic energy dissipation and electron-phonon coupling; it also provides insights for creating novel interfaces and nanostructures to functionalize thin film structures, including tunable electronic, ionic, magnetic and optical properties.
ADDENDUM TO `FIXED ENERGY INVERSE PROBLEM FOR EXPONENTIALLY DECREASING POTENTIALS'
Vasy, AndrÃ¡s
ADDENDUM TO `FIXED ENERGY INVERSE PROBLEM FOR EXPONENTIALLY DECREASING POTENTIALS' GUNTHER UHLMANN with magnetic potential at a #12;xed energy. Commun. Math. Phys., 173:199{224, 1995. [2] R. B. Melrose AND ANDR #19; AS VASY The main result of this paper was a new proof of the #12;xed energy inverse result
Re-examining Potential for Geothermal Energy in United States
Randy Showstack
2003-01-01
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
Solar energy in India: Strategies, policies, perspectives and future potential
Naveen Kumar Sharma; Prashant Kumar Tiwari; Yog Raj Sood
Renewable energy sources and technologies have potential to provide solutions to the longstanding energy problems being faced by the developing countries like India. Solar energy can be an important part of India's plan not only to add new capacity but also to increase energy security, address environmental concerns, and lead the massive market for renewable energy. Solar thermal electricity (STE)
NASA Astrophysics Data System (ADS)
Croft, James F. E.; Hutson, Jeremy M.
2013-03-01
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.
NASA Astrophysics Data System (ADS)
Bostock, Christopher J.; Berrington, Michael J.; Fursa, Dmitry V.; Bray, Igor
2011-08-01
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.
Figure 5. Adiabatic 3 u potential energy curves dissociating
Figure 5. Adiabatic 3 + u potential energy curves dissociating from K(4s)+K(6p) to K(4s)+K(5f). Figure 3 : Adiabatic 1 + u potential energy curves dissociating from K(4s)+K(6p) to K(4s)+K(5f). Figure 2 . Adiabatic 1 + g potential energy curves dissociating from K(4s)+K(6p) to K(4s)+K(5f) . TRANSFER K(7s)-K(5f
NASA Astrophysics Data System (ADS)
Sun, Kyung Ho; Kim, Yoon Young
2010-05-01
Magneto-electro-elastic (MEE) laminate composites with piezoelectric and piezomagnetic phases can be utilized as materials providing energy conversion among magnetic, electric and mechanical energies. This work is concerned with the development of a systematic design method of MEE composites with maximized conversion of mechanical energy to electric and/or magnetic energy. To predict the energy conversion phenomena, a fully coupled MEE theory is employed. A composite plate is assumed to be simply supported and is discretized into a number of laminates for analysis using a semi-analytic finite element method. Since the optimal stacking sequences for piezoelectric/piezomagnetic phases and the optimal thickness for each phase must be simultaneously determined, we propose formulating the design problem as a topology optimization problem. To implement the topology optimization, two interpolation models, the standard SIMP (solid isotropic material with penalization) model and the micromechanics model, are investigated. After solving benchmark test problems, design examples dealing with multifunctional composites are considered.
Semari, F. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali Liabes de Sidi Bel Abbes, Sidi Bel Abbes 22000 (Algeria); Khenata, R. [Laboratoire de Physique Quantique et de Modelisation Mathematique (LPQ3M), Departement de Technologie, Universite de Mascara, Mascara 29000 (Algeria); Depatment of Physics and Astronomy, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia); Rabah, M. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali Liabes de Sidi Bel Abbes, Sidi Bel Abbes 22000 (Algeria); Bouhemadou, A. [Depatment of Physics and Astronomy, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia); Laboratory for Developing New Materials and their Characterization, Faculty of Science, University of Setif, 19000 Setif (Algeria); Bin Omran, S. [Depatment of Physics and Astronomy, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia); Reshak, Ali H., E-mail: maalidph@yahoo.co.u [Institute of Physical Biology, South Bohemia University, Nove Hrady 373 33 (Czech Republic); School of Microelectronic Engineering, University Malaysia Perlis (UniMAP), Block A, Kompleks Pusat Pengajian, 02600 Arau Jejawi, Perlis (Malaysia); Rached, D. [Laboratoire des Materiaux Magnetiques, Departement de Physique, Faculte des Sciences, Universite Djillali Liabes de Sidi Bel Abbes, Sidi Bel Abbes 22000 (Algeria)
2010-12-15
The structural, elastic, electronic, and optical properties of cubic spinel MgIn{sub 2}S{sub 4} and CdIn{sub 2}S{sub 4} compounds have been calculated using a full relativistic version of the full-potential linearized-augmented plane wave with the mixed basis FP/APW+lo method. The exchange and correlation potential is treated by the generalized-gradient approximation (GGA). Moreover, the Engel-Vosko GGA formalism is also applied to optimize the corresponding potential for band structure calculations. The ground state properties, including the lattice constants, the internal parameter, the bulk modulus, and the pressure derivative of the bulk modulus are in reasonable agreement with the available data. Using the total energy-strain technique, we have determined the full set of first-order elastic constants C{sub ij} and their pressure dependence, which have not been calculated or measured yet. The shear modulus, Young's modulus, and Poisson's ratio are calculated for polycrystalline XIn{sub 2}S{sub 4} aggregates. The Debye temperature is estimated from the average sound velocity. Electronic band structures show a direct band gap ({Gamma}-{Gamma}) for MgIn{sub 2}S{sub 4} and an indirect band gap (K-{Gamma}) for CdIn{sub 2}S{sub 4}. The calculated band gaps with EVGGA show a significant improvement over the GGA. The optical constants, including the dielectric function {epsilon}({omega}), the refractive index n({omega}), the reflectivity R({omega}), and the energy loss function L({omega}) were calculated for radiation up to 30 eV. -- Graphical abstract: Calculated total and partial densities of states for MgIn{sub 2}S{sub 4} and CdIn{sub 2}S{sub 4}
Alexander Unzicker; Karl Fabian
2003-01-28
A circular twist disclination is a nontrivial example of a defect in an elastic continuum that causes large deformations. The minimal potential energy and the corresponding displacement field is calculated by solving the Euler-Lagrange-equations. The nonlinear incompressibility constraint is rigorously taken into account. By using an appropriate curvilinear coordinate system a finer resolution in the regions of large deformations is obtained and the dimension of the arising nonlinear PDE's is reduced to two. The extensive algebraic calculations that arise are done by a computer algebra system (CAS). The PDE's are then solved by a difference scheme using the Newton-Raphson algorithm of successive approximations for multidimensional equations. Additional features for global convergence are implemented. To obtain basic states that are sufficiently close to the solution, a one dimensional linearized version of the equation is solved with a numerical computation that reproduces the analytical results of Huang and Mura (1970). With this method, rigorous solutions of the nonlinear equations without any additional simplifications can be obtained. The numerical results show a contraction of the singularity line which corresponds to the well-known Poynting effect in nonlinear elasticity. This combination of analytical and numerical computations proves to be a versatile method to solve nonlinear boundary value problems in complicated geometries.
Nitz, D.E.; Gao, R.S.; Johnson, L.K.; Smith, K.A.; Stebbings, R.F.
1987-06-01
Absolute differential cross sections for He+He elastic scattering at laboratory angles in the range 0.018/sup 0/--0.5/sup 0/ have been measured for projectile energies of 0.5, 1.5, and 5.0 keV. The experiment employs a position-sensitive detector for determining the angular distribution of scattered particles. The differential cross sections exhibit a transition from classical to quantum behavior within the range of angles studied, and excellent agreement is observed with partial-wave-theory calculations using phase shifts derived from the He-He interaction potentials of Ceperley and Partridge (J. Chem. Phys. 84, 820 (1986)) and Foreman, Rol, and Coffin (J. Chem. Phys. 61, 1658 (1974)).
Microscopic self-energy calculations and dispersive optical-model potentials
S. J. Waldecker; C. Barbieri; W. H. Dickhoff
2011-05-21
Nucleon self-energies for 40Ca, 48Ca, 60Ca 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 40Ca and 48Ca. The \\textit{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 non-locality 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 FPRA self-energies are explored. The global features of the FRPA self-energies are not strongly dependent on the choice of realistic nucleon-nucleon interaction.
Single-collision approximation for p{sup 3}-He elastic scattering at low energy
Abusini, M., E-mail: abusini@aabu.edu.j [Al-albayt University, Department of Physics (Jordan)
2009-06-15
A theoretical approach to studying four-body reactions of p{sup 3}-He elastic scattering that takes consistently into account the single-collision mechanism is reported. The theoretical results obtained by this method were compared with experimental data, and the agreement is found to be quite satisfactory.
Interference between Coulomb and hadronic scattering in elastic high-energy nucleon collisions
Vojt?ch Kundrát; Miloš Lokají?ek
2004-12-06
The different models of elastic nucleon scattering amplitude will be discussed. Especially, the preference of the more general approach based on eikonal model will be summarized in comparison with the West and Yennie amplitude that played an important role in analyzing corresponding experimental data in the past.
HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS
PARSA,Z.
2000-04-07
In this paper, high energy physics possibilities and future colliders are discussed. The {mu}{sup +} {mu}{sup {minus}} collider and experiments with high intensity muon beams as the stepping phase towards building Higher Energy Muon Colliders (HEMC) are briefly reviewed and encouraged.
Energy in America: Progress and Potential.
ERIC Educational Resources Information Center
American Petroleum Inst., Washington, DC.
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,…
Energy conservation potential of surface modification technologies
Le, H.K.; Horne, D.M.; Silberglitt, R.S.
1985-09-01
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.
Atomistic potentials based energy flux integral criterion for dynamic adiabatic shear banding
NASA Astrophysics Data System (ADS)
Xu, Yun; Chen, Jun
2015-02-01
The energy flux integral criterion based on atomistic potentials within the framework of hyperelasticity-plasticity is proposed for dynamic adiabatic shear banding (ASB). System Helmholtz energy decomposition reveals that the dynamic influence on the integral path dependence is originated from the volumetric strain energy and partial deviatoric strain energy, and the plastic influence only from the rest part of deviatoric strain energy. The concept of critical shear banding energy is suggested for describing the initiation of ASB, which consists of the dynamic recrystallization (DRX) threshold energy and the thermal softening energy. The criterion directly relates energy flux to the basic physical processes that induce shear instability such as dislocation nucleations and multiplications, without introducing ad-hoc parameters in empirical constitutive models. It reduces to the classical path independent J-integral for quasi-static loading and elastic solids. The atomistic-to-continuum multiscale coupling method is used to simulate the initiation of ASB. Atomic configurations indicate that DRX induced microstructural softening may be essential to the dynamic shear localization and hence the initiation of ASB.
Coulomb suppression in the low-energy p-p elastic scattering via the Trojan Horse Method
Tumino, A. [Laboratori Nazionali del Sud-INFN, via S. Sofia 62, 95123 Catania, Italy and Dipartimento di Metodologie Fisiche e Chimiche per l'Ingegneria, Universita di Catania (Italy); Universita degli Studi di Enna 'Kore', Enna (Italy); Spitaleri, C.; Rapisarda, G. G.; Cherubini, S.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Romano, S.; Sergi, M. L. [Laboratori Nazionali del Sud-INFN, via S. Sofia 62, 95123 Catania, Italy and Dipartimento di Metodologie Fisiche e Chimiche per l'Ingegneria, Universita di Catania (Italy); Mukhamedzhanov, A. [Cyclotron Institute, Texas A and M University, College Station (United States); Campajola, L. [Dipartimento di Scienze Fisiche-Universita Federico II, Napoli (Italy); Elekes, Z.; Fueloep, Zs.; Gyuerky, G.; Kiss, G. G.; Somorjai, E. [ATOMKI-Debrecen (Hungary); Gialanella, L. [INFN-Sezione di Napoli (Italy)
2010-11-24
We present here an important test of the main feature of the Trojan Horse Method (THM), namely the suppression of Coulomb effects in the entrance channel due to off-energy-shell effects. This is done by measuring the THM p-p elastic scattering via the p+d{yields}p+p+n reaction at 4.7 and 5 MeV, corresponding to a p-p relative energy ranging from 80 to 670 keV. In contrast to the on-energy-shell (OES) case, the extracted p-p cross section does not exhibit the Coulomb-nuclear interference minimum due to the suppression of the Coulomb amplitude. This is confirmed by the half-off-energy shell (HOES) calculations and strengthened by the agreement with the calculated OES nuclear cross sections.
NASA Astrophysics Data System (ADS)
Baek, W. Y.; Bug, M. U.; Rabus, H.
2014-06-01
Differential elastic electron-scattering cross sections of pyrimidine were absolutely measured for electron energies from 20 eV to 1 keV in the angular range between 5° and 135°. The present results agree with the data of other groups within the experimental uncertainties at scattering angles below 75° while considerable differences among the data were found at higher scattering angles. The experimental values were compared to theoretical values calculated using the modified independent-atom model. The theoretical values reproduce the angular dependence of the experimental differential elastic scattering cross sections qualitatively well for electron energies above 60 eV. The sum of the integral elastic scattering cross sections, obtained by the integration of the differential elastic scattering cross sections, and ionization cross sections predicted by the binary-encounter-Bethe model agree with the previously measured total electron-scattering cross sections of pyrimidine to within 8%.
Polarizable interaction potential for water from coupled cluster calculations. I. Analysis of dimer online 7 March 2008 A six-dimensional interaction potential for the water dimer has been fitted to ab potential energy surface Robert Bukowski,1 Krzysztof Szalewicz,1,a Gerrit C. Groenenboom,2 and Ad van der
Bonet, J.
We present an implicit a-posteriori finite element procedure to compute bounds for functional outputs of finite element solutions in large strain elasticity. The method proposed relies on the existence of a potential energy ...
Derivation of climate elasticity of runoff to assess the effects of climate change on annual runoff
NASA Astrophysics Data System (ADS)
Yang, Hanbo; Yang, Dawen
2011-07-01
Climate elasticity of runoff is an important indicator for evaluating the effects of climate change on runoff. Consequently, this paper proposes an analytical derivation of climate elasticity. Based on the mean annual water-energy balance equation, two dimensionless numbers (the elasticities of runoff to precipitation and potential evaporation) were derived. Combining the first-order differential of the Penman equation, the elasticities of runoff to precipitation, net radiation, air temperature, wind speed, and relative humidity were derived to separate the contributions of different climatic variables. The case study was carried out in the Futuo River catchment in the Hai River basin, as well as in 89 catchments of the Hai River and the Yellow River basins of China. Based on the mean annual of climatic variables, the climate elasticity in the Futuo River basin was estimated as follows: precipitation elasticity ?, net radiation elasticity ?, air temperature elasticity ?, wind speed elasticity ?, and relative humidity elasticity ?. In this catchment, precipitation decrease was mainly responsible for runoff decline, and wind speed decline had the second greatest effect on runoff. In the 89 catchments of the Hai River and the Yellow River basins of China, climate elasticity was estimated as follows: ? ranging from 1.6 to 3.9, ? ranging from -1.9 to -0.3, ? ranging from -0.11 to -0.02°C-1, ? ranging from -0.8 to -0.1, and ? ranging from 0.2 to 1.9. Additional analysis shows that climate elasticity was sensitive to catchment characteristics.
Dissociation Energies and Potential Energy Functions for the Ground X 1
Le Roy, Robert J.
Dissociation Energies and Potential Energy Functions for the Ground X 1 + and `Avoided potential energy functions incorporat- ing the correct theoretically predicted long-range behaviour determination of centrifugal (non-adiabatic) and potential-energy (adiabatic) Born-Oppenheimer breakdown
Low-energy proton-deuteron elastic scattering and the A(y) puzzle
NASA Astrophysics Data System (ADS)
Wood, Michael H.
2000-10-01
Angular distributions of cross sections and complete sets of analyzing powers have been measured for d-p scattering at a center-of-mass energy of 667 +/- 1 keV. This set of high-precision data was compared to the most recent variational calculations with the nucleon- nucleon potential AV18 alone and with AV18 plus the UR three- nucleon potential. The calculations have the best agreement with the cross-section data while the comparison with the tensor analyzing powers showed good agreement. However, a comparison between the vector analyzing powers revealed differences of approximately 40% in the maxima of the angular distributions. These NAP discrepancies have been observed at Ec.m. >= 2.0 MeV as well as in the n-d scattering case. After the n-d experiments, the problem has been labelled the `` Ay Puzzle''. A ?2/datum analysis was performed with the lowest values achieved by the inclusion of a three- nucleon force in the theoretical calculations. This fact provides more credence for the existence of three-nucleon forces. However, the ?2/datum for the VAPs remained approximately 100. To investigate the root of the problem in addition to other differences between the theory and the data, a single-energy phase shift analysis (PSA) was performed. The best fits to the NAP data displayed an ~20% increase in the mixing parameter e/- and an increase in the splitting between 4 PJ phase shifts from the variational calculations with the AV18+UR potentials.
Potential-energy surfaces for asymmetric heavy-ion reactions
P. Möller; J. R. Nix
1977-01-01
We calculate the macroscopic potential energy of deformation as a function of mass asymmetry and distance between mass centers for shape configurations of interest in heavy-ion reactions. For the system300120 we also study the effect of adding microscopic shell and pairing corrections to the macroscopic potential energy. The shape configurations are generated by bringing together two separated spheres of unequal
An Iterative Global Optimization Algorithm for Potential Energy Minimization
energies of up to ¡£¢ atoms are reported. Keywords: Many-body, pair potential, differential evolution of the stable structure of atoms or molecules [4, 5]. Therefore, the determination of the global minimum energy configuration, or the ground state structures, for clusters of atoms or molecules, predicted by the potential
Haibo, Xu
2014-01-01
A version of Geant4 has been developed to treat high-energy proton radiography. This article presents the results of calculations simulating the effects of nuclear elastic scattering for various test step wedges. Comparisons with experimental data are also presented. The traditional expressions of the transmission should be correct if the angle distribution of the scattering is Gaussian multiple Coulomb scattering. The mean free path which depends on the collimator angle and the radiation length are treated as empirical parameters, according to transmission as a function of thickness obtained by simulations. The results benefit for reconstructing density that depends on the transmission expressions.
NASA Astrophysics Data System (ADS)
Merlet, Benoît
2015-08-01
We propose a nonlinear elasticity model for vesicle membranes which is an Eulerian version of a model introduced by Pantz and Trabelsi. We describe the limit behavior of sequences of configurations whose energy goes to 0 in a fixed domain. The material is highly anisotropic and the analysis is based on some rigidity estimates adapted to this anisotropy. The main part of the paper is devoted to these estimates and to some of their consequences. The strongest form of these estimates are used in a second article to derive the thin-shell limit bending theory of the model.
Potential energy savings on the MIT campus
Amanti, Steven Thomas
2006-01-01
The MIT community and the City of Cambridge embarked on initiatives to reduce energy consumption and Greenhouse Gas emissions in accordance with the Kyoto Protocol which calls for a 20 % reduction in 1990 levels of GHG ...
Energy Savings Potential and Research & Development Opportunities for Commercial Refrigeration
2009-09-30
This study documents the energy consumption of commercial refrigeration equipment (CRE) in the U.S. and evaluated the energy savings potential of various technologies and energy efficiency measures that could be applied to such equipment. The study provided an overview of CRE applications, assessed the energy-savings potential of CRE in the U.S., outline key barriers to adoption of energy-savings technologies, and recommended opportunities for advanced energy saving technology research. The study was modeled after an earlier 1996 report by Arthur D. Little, Inc., and updated key information, examined more equipment types, and outlined long-term research and development opportunities.
Potential Energy Sources Pose Mining Problem
ERIC Educational Resources Information Center
Chemical and Engineering News, 1974
1974-01-01
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)
Diabatic potential energy surfaces of H + + CO
F. George D X; Sanjay Kumar
2007-01-01
Ab initio adiabatic and diabatic surfaces of the ground and the first excited electronic states have been computed for the H+ + CO system for the collinear (? = 0°) and the perpendicular (? = 90°) geometries employing the multi-reference configuration interaction method and Dunning’s cc-pVTZ basis set. Other properties such as mixing angle before coupling potential and before coupling
Saturation wind power potential and its implications for wind energy
Saturation wind power potential and its implications for wind energy Mark Z. Jacobsona,1 to determine the maximum theo- retical wind power potential on Earth, based on the concept of "saturation". The saturation wind power potential (SWPP) is the maximum wind power that can be extracted upon increasing
Magazu, Salvatore; Migliardo, Federica; Benedetto, Antonio [Dipartimento di Fisica, Universita di Messina, C.da Papardo n Degree-Sign 31, P.O. Box 55, Vill. S. Agata 98166 Messina (Italy)
2012-10-15
Recently [S. Magazu et al., Rev. Sci. Instrum. 82, 105115 (2011)] we have proposed a new method for characterizing, by neutron scattering, the dynamical properties of complex material systems, such as, the ones of interest in the biophysical field. This approach called Resolution Elastic Neutron Scattering, in short RENS, is based on the detection of the elastically scattered neutron intensity as a function of the instrumental energy resolution. By experimental, theoretical, and numerical findings, we have pointed out that an inflection point occurs in the elastic intensity when the system relaxation time approaches the instrumental energy resolution time. This approach, differently from quasi-elastic neutron scattering (QENS), gives the chance to evaluate the system relaxation times without using pre-defined models that can be wrong and/or misleading. Here, we reply to a Comment on the above-mentioned main paper in which Wuttke proposes a different approach to evaluate the above-mentioned inflection point; on this regard, it should be noticed that the existence of the inflection point, which is the main topic of our work, is not questioned and that the approach proposed by Wuttke in the Comment, although valid for a class of dynamical processes, is not applicable when different and distinct processes occur simultaneously at different time scale.
Zheqiang Shi; Alan Needleman; Yehuda Ben-Zion
2010-01-01
The effect of plasticity on dynamic frictional sliding along an interface between two identical elastic–viscoplastic solids\\u000a is analyzed. The configuration considered is the same as that in Coker et al. (J Mech Phys Solids 53:884–992, 2005) except\\u000a that here plane strain analyses are carried out and bulk material plasticity is accounted for. The specimens have an initial\\u000a compressive stress and are
Measurement of np elastic scattering at high energies and very small momentum transfers
A. Arefiev; A. Babaev; A. Bamberger; H.-J. Brundiers; G. Eliseev; U. Fischer; D. Friedrich; Yu. Galaktionov; Yu. Gorodkov; R. Hartung; W. Heck; Yu. Kamyshkov; V. Lubimov; R. Maier; V. Plyaskin; V. Pojidaev; K. Runge; O. Schaile; V. Schevchenko; B. Thomauske; M. Vlasov; Ch. Weber
1984-01-01
The np elastic differential cross section has been measured for incident neutron momenta 100-400 GeV\\/c in the t range 6 . 10-6 - 5 . 10-1 (GeV\\/c)2. The np data of this experiment provide a first direct measurement of the hadronic amplitude for t < 10-2 (GeV\\/c)2, which is consistent with the extrapolations from higher t values. Our data for
Preliminary evaluation of wind energy potential: Cook Inlet area, Alaska
Hiester, T.R.
1980-06-01
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.
NASA Astrophysics Data System (ADS)
Kuang, Jun; Dai, Zhaohe; Liu, Luqi; Yang, Zhou; Jin, Ming; Zhang, Zhong
2015-05-01
Nanostructured carbon material based three-dimensional porous architectures have been increasingly developed for various applications, e.g. sensors, elastomer conductors, and energy storage devices. Maintaining architectures with good mechanical performance, including elasticity, load-bearing capacity, fatigue resistance and mechanical stability, is prerequisite for realizing these functions. Though graphene and CNT offer opportunities as nanoscale building blocks, it still remains a great challenge to achieve good mechanical performance in their microarchitectures because of the need to precisely control the structure at different scales. Herein, we fabricate a hierarchical honeycomb-like structured hybrid foam based on both graphene and CNT. The resulting materials possess excellent properties of combined high specific strength, elasticity and mechanical stability, which cannot be achieved in neat CNT and graphene foams. The improved mechanical properties are attributed to the synergistic-effect-induced highly organized, multi-scaled hierarchical architectures. Moreover, with their excellent electrical conductivity, we demonstrated that the hybrid foams could be used as pressure sensors in the fields related to artificial skin.Nanostructured carbon material based three-dimensional porous architectures have been increasingly developed for various applications, e.g. sensors, elastomer conductors, and energy storage devices. Maintaining architectures with good mechanical performance, including elasticity, load-bearing capacity, fatigue resistance and mechanical stability, is prerequisite for realizing these functions. Though graphene and CNT offer opportunities as nanoscale building blocks, it still remains a great challenge to achieve good mechanical performance in their microarchitectures because of the need to precisely control the structure at different scales. Herein, we fabricate a hierarchical honeycomb-like structured hybrid foam based on both graphene and CNT. The resulting materials possess excellent properties of combined high specific strength, elasticity and mechanical stability, which cannot be achieved in neat CNT and graphene foams. The improved mechanical properties are attributed to the synergistic-effect-induced highly organized, multi-scaled hierarchical architectures. Moreover, with their excellent electrical conductivity, we demonstrated that the hybrid foams could be used as pressure sensors in the fields related to artificial skin. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00841g
NASA Astrophysics Data System (ADS)
Loan, Doan Thi; Loc, Bui Minh; Khoa, Dao T.
2015-09-01
The nucleon mean-field potential has been thoroughly investigated in an extended Hartree-Fock (HF) calculation of nuclear matter (NM) using the CDM3Y3 and CDM3Y6 density dependent versions of the M3Y interaction. The single-particle (SP) energies of nucleons in NM are determined according to the Hugenholtz-Van Hove theorem, which gives rise naturally to a rearrangement term (RT) of the SP potential at the Fermi momentum. Using the RT obtained exactly at the different NM densities and neutron-proton asymmetries, a consistent method is suggested to take into account effectively the momentum dependence of the RT of the SP potential within the standard HF scheme. To obtain a realistic momentum dependence of the nucleon optical potential (OP), the high-momentum part of the SP potential was accurately readjusted to reproduce the observed energy dependence of the nucleon OP over a wide range of energies. The impact of the RT and momentum dependence of the SP potential on the density dependence of the nuclear symmetry energy and nucleon effective mass has been studied in detail. The high-momentum tail of the SP potential was found to have a sizable effect on the slope of the symmetry energy and the neutron-proton effective mass splitting at supranuclear densities of the NM. Based on a local density approximation, the folding model of the nucleon OP of finite nuclei has been extended to take into account consistently the RT and momentum dependence of the nucleon OP in the same mean-field manner, and successfully applied to study the elastic neutron scattering on the lead target at the energies around the Fermi energy.
Potential production of energy cane for fuel in the Caribbean
Samuels, G.
1984-12-01
Sugarcane presents a tremendous potential as a renewable energy source for the non-oil producing countries of the Caribbean. The energy cane concept is sugarcane managed for maximum dry matter (total fermentable solids for alcohol fuel and combustible solids for electricity) rather than sucrose. The use of sugarcane as a renewable energy source can provide a solution, either partial or total, to the Caribbean energy problem. Sugar cane production and the use of this crop as a renewable energy source are described.
Energy Stored in a Capacitor What is the potential energy, U, of a
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Energy Stored in a Capacitor What is the potential energy, U, of a charged capacitor? Think of U energy by discharging capacitor VqWU == #12;Energy Stored in a Capacitor Charge capacitor by transferring takes positive work to charge capacitor #12;Energy Stored in a Capacitor At given instance potential
Mechanism of Resilin Elasticity
Qin, Guokui; Hu, Xiao; Cebe, Peggy; Kaplan, David L.
2012-01-01
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. PMID:22893127
Mechanism of resilin elasticity.
Qin, Guokui; Hu, Xiao; Cebe, Peggy; Kaplan, David L
2012-01-01
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 nanoporous patterns formed after beta-turn structures were present via changes in either the thermal or the 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. Furthermore, this model offers a view of elastomeric proteins in general where beta-turn-related structures serve as fundamental units of the structure and elasticity. PMID:22893127
NASA Astrophysics Data System (ADS)
Marks, R.; Garg, U.; Madhusudana Rao, P. V.; Li, T.
2004-10-01
Study of the isoscaler giant dipole resonance (ISGDR) is a useful way of determining nuclear incompressibility---an important property of the nucleus because of its ties to the physics of neutron star formation and supernovae. In order to properly analyze the strength of the ISGDR by separating the contributions from other multipole resonances, the single-folding optical potential model is first needed to characterize the behavior of the nucleus. Elastic scattering experiments were run at the ring cyclotron facility at RCNP, Osaka University, using a 400 MeV ? beam. Momentum and particle trajectory data was collected by the Grand Raiden magnetic spectrometer after scattering from the target isotopes ^112Sn and ^124Sn. Using this data, differential cross sections of the elastic scattering peaks were obtained, and analysis done to determine the optimum parameters for the single-folding model. These parameters were verified by comparing the theoretical and experimental angular distributions of the low-lying inelastic states. Results and analysis will be presented in detail.
NASA Astrophysics Data System (ADS)
Ogloblin, A. A.; Glukhov, Yu. A.; Trzaska, W. H.; Dem'yanova, A. S.; Goncharov, S. A.; Julin, R.; Klebnikov, S. V.; Mutterer, M.; Rozhkov, M. V.; Rudakov, V. P.; Tiorin, G. P.; Khoa, Dao T.; Satchler, G. R.
2000-10-01
For the first time, differential cross section of the 16O+12C elastic scattering at Elab=170, 200, 230, and 260 MeV has been measured over a wide angular range which covers both diffractive and refractive regions. In addition, the recent data at 132 MeV for this system have been remeasured with much better statistics. A well developed rainbow structure has been observed, where up to three Airy minima could be identified in each measured angular distribution. The optical model analysis of these data was done using the conventional Woods-Saxon shape for the optical potential as well as that given by the folding model. The Airy systematics enabled us to suggest a realistic family of the optical potential for the 16O+12C system, which consistently describes the new data as well as the data measured earlier at incident energies of 608 and 1503 MeV. Our results show that the 16O+12C system is a very suitable heavy-ion combination for the study of refractive phenomena, which can give important information on the nucleus-nucleus potential at small distances.
Comparing energy levels in isotropic and anisotropic potentials
Alexander Pikovski
2015-06-28
Qualitative information about the quantized energy levels of a system can be of great value. We study the relationship between the bound-state energies of an anisotropic potential and those of its spherical average. It is shown that the two ground-state energies satisfy an inequality, and there is a similar inequality for the first excited states.
Estimating the Potential Impact of Renewable Energy on the Caribbean
Kammen, Daniel M.
Estimating the Potential Impact of Renewable Energy on the Caribbean Job Sector Rebekah Shirley Daniel Kammen University of California Berkeley Renewable and Appropriate Energy Laboratory (RAEL) & Energy and Resources Group and Goldman School of Public Policy Release date: April 15, 2012 #12
Geothermal energy potential in the San Luis Valley, Colorado
Coe, B.A.
1980-01-01
The background of the area itself is investigated considering the geography, population, economy, attitudes of residents, and energy demands of the area. The requirements for geothermal energy development are considered, including socio-economic, institutional, and environmental conditions as well as some technical aspects. The current, proposed, and potential geothermal energy developments are described. The summary, conclusions, and methodology are included. (MHR)
Periodic Discrete Energy for Long-Range Potentials
D. P. Hardin; E. B. Saff; Brian Simanek
2014-12-11
We consider periodic energy problems in Euclidean space with a special emphasis on long-range potentials that cannot be defined through the usual infinite sum. One of our main results builds on more recent developments of Ewald summation to define the periodic energy corresponding to a large class of long-range potentials. Two particularly interesting examples are the logarithmic potential and the Riesz potential when the Riesz parameter is smaller than the dimension of the space. For these examples, we use analytic continuation methods to provide concise formulas for the periodic kernel in terms of the Epstein Hurwitz Zeta function. We apply our energy definition to deduce several properties of the minimal energy including the asymptotic order of growth and the distribution of points in energy minimizing configurations as the number of points becomes large. We conclude with some detailed calculations in the case of one dimension, which shows the utility of this approach.
Potential energy surfaces for the (ArCO) + system
NASA Astrophysics Data System (ADS)
Parlant, Gérard; Archirel, Pierre; Gislason, Eric A.
1990-01-01
The five lowest doublet potential energy surfaces for the (ArCO)+ system have been determined using the procedure of Archirel and Levy. These states correlate at infinite separation, in order of increasing energy, to Ar+CO+(X 2?+), Ar+(2P3/2)+CO, Ar+(2P1/2)+CO, and Ar+CO+(A 2?). The potential energy curves are shown at several values of the orientation angle. In addition, contour maps of the two lowest surfaces are presented. Both of these surfaces are quite anisotropic, and each has a deep potential well. Adiabatic vibronic potential energy surfaces have also been computed. These give insight into the charge transfer process at low collision energies. For the purpose of comparison the five lowest surfaces for the isoelectronic system (ArN2)+ are also shown.
Brittle fracture in a periodic structure with internal potential energy
Mishuris, Gennady S.; Slepyan, Leonid I.
2014-01-01
We consider a brittle fracture taking account of self-equilibrated distributed stresses existing at microlevel in the absence of external forces. To determine how the latter can affect the crack equilibrium and growth, a model of a structured linearly elastic body is introduced, consisting of two equal symmetrically arranged layers (or half-planes) connected by an interface as a prospective crack path. The interface comprises a discrete set of elastic bonds. In the initial state, the bonds are assumed to be stressed in such a way that tensile and compressive forces of the same value alternate. In the general considerations, the layers are assumed to be of an unspecified periodic structure, where such self-equilibrated stresses may also exist. A two-line chain and a lattice are examined as the specified structure. We consider the states of the body-with-a-crack under such microlevel stresses (MS) and under a combined action of the remote forces and MS. Analytical solutions to the considered problems are presented based on the introduction of a selective discrete transform. We demonstrate that MS can increase as well as decrease the crack resistance depending on the internal energy level. We also discuss different scenarios of the crack growth. PMID:24808756
NASA Astrophysics Data System (ADS)
Mookherjee, Mainak; Karki, Bijay B.; Stixrude, Lars; Lithgow-Bertelloni, Carolina
2012-10-01
The new aluminous (NAL) phase and aluminous phase with calcium ferrite (CF) structure constitutes more than 25 volume % of the deeply subducted crust at lower mantle depths. Using first principle simulations, we calculate the energetics, equation of state, and elasticity of NAL phase with a widely varying composition including CaMg2Al6O12, NaNa2Al3Si3O12 and KNa2Al3Si3O12. Our calculations indicate the relative stability of NAL and CF phases is a sensitive function of pressure, temperature, and composition, with increasing pressure tending to favor the CF phase, and increasing temperature, Mg-content and alkali-content tending to favor the NAL phase. The sound wave velocities of the NAL phase is significantly lower than CF phases and other major lower mantle phases. In deeply subducted MORB and CC, the faster sound velocity of silica (SiO2) and its high-pressure polymorphic phase is likely to be compensated with the slower sound wave velocities of NAL phase.
Industrial Energy Conservation Potentials in North Carolina
Barakat, M. G.; Singh, H.; Mallik, A. K.
1987-01-01
272,017 2,680,047 2,291,408 438 ;. Table 2 Gommonly Siggested ECOs ECO /I Savings ImpL i'. MMBTU $ Cost '. Efficient Lighting Management 74 13,581 208,968 193,084 Use Effie. Motors 70 26,550 388,011 398,389 Relocate Compr. Intake Outside... boiler tune-up. As Table 2 shows, not all of the ECOs mentioned above have been commonly recommended, because some of them either have too long a payback period (over two years), or the energy savings are not large enough to justify implementation...
Kuang, Jun; Dai, Zhaohe; Liu, Luqi; Yang, Zhou; Jin, Ming; Zhang, Zhong
2015-05-28
Nanostructured carbon material based three-dimensional porous architectures have been increasingly developed for various applications, e.g. sensors, elastomer conductors, and energy storage devices. Maintaining architectures with good mechanical performance, including elasticity, load-bearing capacity, fatigue resistance and mechanical stability, is prerequisite for realizing these functions. Though graphene and CNT offer opportunities as nanoscale building blocks, it still remains a great challenge to achieve good mechanical performance in their microarchitectures because of the need to precisely control the structure at different scales. Herein, we fabricate a hierarchical honeycomb-like structured hybrid foam based on both graphene and CNT. The resulting materials possess excellent properties of combined high specific strength, elasticity and mechanical stability, which cannot be achieved in neat CNT and graphene foams. The improved mechanical properties are attributed to the synergistic-effect-induced highly organized, multi-scaled hierarchical architectures. Moreover, with their excellent electrical conductivity, we demonstrated that the hybrid foams could be used as pressure sensors in the fields related to artificial skin. PMID:25932597
Joost H. Weijs; Bruno Andreotti; Jacco H. Snoeijer
2013-05-30
The capillary forces exerted by liquid drops and bubbles on a soft solid are directly measured using molecular dynamics simulations. The force on the solid by the liquid near the contact line is not oriented along the liquid vapor interface nor perpendicular to the solid surface, as usually assumed, but points towards the liquid. It is shown that the elastic deformations induced by this force can only be explained if, contrary to an incompressible liquid, the surface stress is different from the surface energy. Using thermodynamic variations we show that the the surface stress and the surface energy can both be determined accurately by measuring the deformation of a slender body plunged in a liquid. The results obtained from molecular dynamics fully confirm those recently obtained experimentally [Marchand et al. Phys. Rev. Lett. 108, 094301 (2012)] for an elastomeric wire.
Baigts Allende, Diana; de Jongh, Harmen H J
2015-08-12
To better tailor gelatins for textural characteristics in (food) gels, their interactions are destabilized by introduction of electrostatic repulsions and creation of affinity sites for calcium to "lock" intermolecular interactions. For that purpose gelatins with various degrees of succinylation are obtained. Extensive succinylation hampers helix formation and gel strength is slightly reduced. At high degrees of succinylation the helix propensity, gelling/melting temperatures, concomitant transition enthalpy, and gel strength become calcium-sensitive, and relatively low calcium concentrations largely restore these properties. Although succinylation has a major impact on the brittleness of the gels formed and the addition of calcium makes the material less brittle compared to nonmodified gelatin, the modification has no impact on the energy balance in the gel, where all energy applied is elastically stored in the material. This is explained by the unaffected stress relaxation by the network and high water-holding capacity related to the small mesh sizes in the gels. PMID:26154824
Tavora, Marco; Rosch, Achim; Mitra, Aditi
2014-07-01
The dynamics of interacting bosons in one dimension following the sudden switching on of a weak disordered potential is investigated. On time scales before quasiparticles scatter (prethermalized regime), the dephasing from random elastic forward scattering causes all correlations to decay exponentially fast, but the system remains far from thermal equilibrium. For longer times, the combined effect of disorder and interactions gives rise to inelastic scattering and to thermalization. A novel quantum kinetic equation accounting for both disorder and interactions is employed to study the dynamics. Thermalization turns out to be most effective close to the superfluid-Bose-glass critical point where nonlinearities become more and more important. The numerically obtained thermalization times are found to agree well with analytic estimates. PMID:25032914
Energy savings potential from energy-conserving irrigation systems
Wilfert, G.L.; Patton, W.P.; Harrer, B.J.; Clark, M.A.
1982-11-01
This report systematically compares, within a consistent framework, the technical and economic characteristics of energy-conserving irrigation systems with those of conventional irrigation systems and to determine total energy savings. Levelized annual costs of owning and operating both energy-conserving and conventional irrigation systems have been developed and compared for all 17 states to account for the differences in energy costs and irrigation conditions in each state. Market penetration of energy-conserving systems is assessed for those systems having lower levelized annual costs than conventional systems performing the same function. Annual energy savings were computed by matching the energy savings per system with an assumed maximum market penetration of 100 percent in those markets where the levelized annual costs of energy-conserving systems are lower than the levelized annual costs of conventional systems.
Converted Phase Elastic Migration Velocity Analysis
Shabelansky, Andrey Hanan
2013-01-01
Multi-component elastic seismic data collected at large offsets have the potential to be used in seismic imaging and velocity analysis. In this study, we present an approach for converted-phase elastic-transmission migration ...
New approach to calculating the potential energy of colliding nuclei
Kurmanov, R. S.; Kosenko, G. I.
2014-12-15
The differential method proposed by the present authors earlier for the reduction of volume integrals in calculating the potential energy of a compound nucleus is generalized to the case of two interacting nuclei. The Coulomb interaction energy is obtained for the cases of a sharp and a diffuse boundary of nuclei, while the nuclear interaction energy is found only for nuclei with a sharp boundary, the finiteness of the nuclear-force range being taken into account. The present method of calculations permits reducing the time it takes to compute the potential energy at least by two orders of magnitude.
New approach to calculating the potential energy of colliding nuclei
NASA Astrophysics Data System (ADS)
Kurmanov, R. S.; Kosenko, G. I.
2014-12-01
The differential method proposed by the present authors earlier for the reduction of volume integrals in calculating the potential energy of a compound nucleus is generalized to the case of two interacting nuclei. The Coulomb interaction energy is obtained for the cases of a sharp and a diffuse boundary of nuclei, while the nuclear interaction energy is found only for nuclei with a sharp boundary, the finiteness of the nuclear-force range being taken into account. The present method of calculations permits reducing the time it takes to compute the potential energy at least by two orders of magnitude.
Feature Article Exploring Potential Energy Surfaces for Chemical
Schlegel, H. Bernhard
. Methods for geometry optimization of equilibrium structures, searching for transition states, followingFeature Article Exploring Potential Energy Surfaces for Chemical Reactions: An Overview of Some concept in the application of electronic structure methods to the study of molecular structures
Energy Savings Potential of Process Control Valve Replacement
Holzenthal, L. Jr.
1994-01-01
A review of current design methods for industrial process control systems that utilize modulated control valves as their final element is presented. The infornUltion that is available is then used to find the theoretic potential for energy savings...
Fusion at deep subbarrier energies: potential inversion revisited
K. Hagino; N. Rowley
2008-11-15
For a single potential barrier, the barrier penetrability can be inverted based on the WKB approximation to yield the barrier thickness. We apply this method to heavy-ion fusion reactions at energies well below the Coulomb barrier and directly determine the inter-nucleus potential between the colliding nuclei. To this end, we assume that fusion cross sections at deep subbarrier energies are governed by the lowest barrier in the barrier distribution. The inverted inter-nucleus potentials for the $^{16}$O +$^{144}$Sm and $^{16}$O +$^{208}$Pb reactions show that they are much thicker than phenomenological potentials. We discuss a consequence of such thick potential by fitting the inverted potentials with the Bass function.
POTLIB 2001: A potential energy surface library for chemical systems
Ronald J Duchovic; Yuri L Volobuev; Gillian C Lynch; Donald G Truhlar; Thomas C Allison; Albert F Wagner; Bruce C Garrett; Jose C Corchado
2002-01-01
POTLIB 2001 is a computer program library of global chemical potential energy surface (PES) functions (91 functions in version 1.0) along with test data, a suite of utility programs, and a convenient user interface. The PES programs are written in ANSI standard FORTRAN77 and can be used to determine the Born–Oppenheimer potential energy of chemical systems as a function of
POTLIB 2001: A potential energy surface library for chemical systems
Ronald J. Duchovic; Yuri L. Volobuev; Gillian C. Lynch; Donald G. Truhlar; Thomas C. Allison; Albert F. Wagner; Bruce C. Garrett; Jose C. Corchado
2002-01-01
POTLIB 2001 is a computer program library of global chemical potential energy surface (PES) functions (91 functions in version 1.0) along with test data, a suite of utility programs, and a convenient user interface. The PES programs are written in ANSI standard FORTRAN77 and can be used to determine the Born-Oppenheimer potential energy of chemical systems as a function of
Teaching Potential Energy Functions and Stability with Slap Bracelets
NASA Astrophysics Data System (ADS)
Van Hook, Stephen J.
2005-10-01
The slap bracelet, an inexpensive child's toy, makes it easy to engage students in hands-on exploration of potential energy curves as well as of stable, unstable, and meta-stable states. Rather than just observing the teacher performing a demonstration, the students can manipulate the equipment themselves and make their own observations, which are then pooled to focus a class discussion on potential energy functions and stability.
Re-examining Potential for Geothermal Energy in United States
NASA Astrophysics Data System (ADS)
Showstack, Randy
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 Study Institute. Among these initiatives is an ambitious program of the U.S. Department of Energy to expand existing geothermal energy fields and potentially create new fields through ``enhanced geothermal systems.'' In addition, a program of the Bush administration encourages geothermal development on some public lands, and current legislation would provide tax credits and other incentives for geothermal development.
Potential energy surfaces in algebraic molecular models using coherent states
O. Castaños; R. Lemus
2010-01-01
The potential energy surfaces provided by the coherent states formalism for the case of interacting one-dimensional oscillators is investigated. The case of two interacting oscillators modelled with Morse potentials are considered in detail. First the traditional treatment is presented in order to identify the need to establish a new transformation between the parameters and the classical variables that allow the
Selected Features of Potential Energy Landscapes and Their Inherent Structures
Stillinger, Frank
Lecture December 11, 2003 F.H. Stillinger Slide 1 #12;Potential Energy/Enthalpy Functions for Many symmetry; (g) in a large system, local rearrangements change only by O(1), not O(N). · Extension [configuration space dimension increases to 1)3( ++ N ]. Introduce "potential enthalpy" function , pVVV NN
Energy dependence of nucleon-nucleon potentials in lattice QCD
K. Murano; N. Ishii; S. Aoki; T. Hatsuda
2010-03-02
Recently a new approach to calculate the nuclear potential from lattice QCD has been proposed. In the approach the nuclear potential is constructed from Bethe-Salpeter (BS) wave functons through the Schroedinger equation. The procedure leads to non-local but energy independent potential, which can be expanded in terms of local functions. In several recent applications of this method, local potentials, which correspond to the leading order (LO) terms of the expansion, are calculated from the BS wave function at E~0 MeV, where E is the center of mass energy. It is therefore important to check the validity of the LO approximation obtained at E~0. In this report, in order to check how well the LO approximation for the NN potentials works, we compare the LO potentials determined from the BS wave function at E~45 MeV with those at E~0 MeV in quenched QCD. We find that the difference of the LO potentials between two energies are not found wihin the statistical errors. This shows that the LO approximation for the potential is valid at low energies to describe the NN interactions.
Analytical potential energy functions for some interhalogen diatomic electronic states
NASA Astrophysics Data System (ADS)
Fan, Qunchao; Fan, Zhixiang; Nie, Yanping; Sun, Weiguo; Zhang, Yi; Feng, Hao
2015-01-01
The studies of vibrational energies and analytical potential energy functions (APEFs) have been carried out for four interhalogen diatomic electronic states B(3 ? 0 +) and A(3 ? 1) of ClF, A'(3 ? 2 u ) of Cl2, and the ground state X 1 ?{/g +} of Br2 by using an improved variational algebraic energy-consistent method (VAECM(4)). The full vibrational energies, the vibrational spectroscopic constants, the force constants f n , and the expansion coefficients a n of the ECM (energy-consistent method) potential are tabulated. The VAECM(4) APEF with adjustable variational parameter ? for each electronic state is determined, and is shown to be in excellent agreement with available experimental data and has no any artificial barrier in all the calculation ranges that may appear in some other analytical potentials.
Hoshino, M; Limão-Vieira, P; Anzai, K; Kato, H; Cho, H; Mogi, D; Tanioka, T; Ferreira da Silva, F; Almeida, D; Blanco, F; García, G; Ingólfsson, O; Tanaka, H
2014-09-28
We report absolute elastic differential cross sections for electron interactions with the C4F6 isomers, hexafluoro-1,3-butadiene (1,3-C4F6), hexafluoro-2-butyne (2-C4F6), and hexafluorocyclobutene (c-C4F6). The incident electron energy range is 1.5-200 eV, and the scattered electron angular range for the differential measurements varies from 15° to 150°. In all cases the absolute scale of the differential cross section was set using the relative flow technique, with helium as the reference species. Atomic-like behaviour in these scattering systems is shown here for the first time, and is further investigated by comparing the elastic cross sections for the C4F6 isomers with other fluorinated molecules, such as SF6 and CnF6 (n = 2, 3, and 6). We note that for all the six-F containing molecules, the scattering process for electron energies above 30 eV is indistinguishable. Finally, we report results for calculations of elastic differential cross sections for electron scattering from each of these isomers, within an optical potential method and assuming a screened corrected independent atom representation. The level of agreement between these calculations and our measurements is found to be quite remarkable in all cases. PMID:25273432
NASA Astrophysics Data System (ADS)
Hoshino, M.; Limão-Vieira, P.; Anzai, K.; Kato, H.; Cho, H.; Mogi, D.; Tanioka, T.; Ferreira da Silva, F.; Almeida, D.; Blanco, F.; García, G.; Ingólfsson, O.; Tanaka, H.
2014-09-01
We report absolute elastic differential cross sections for electron interactions with the C4F6 isomers, hexafluoro-1,3-butadiene (1,3-C4F6), hexafluoro-2-butyne (2-C4F6), and hexafluorocyclobutene (c-C4F6). The incident electron energy range is 1.5-200 eV, and the scattered electron angular range for the differential measurements varies from 15° to 150°. In all cases the absolute scale of the differential cross section was set using the relative flow technique, with helium as the reference species. Atomic-like behaviour in these scattering systems is shown here for the first time, and is further investigated by comparing the elastic cross sections for the C4F6 isomers with other fluorinated molecules, such as SF6 and CnF6 (n = 2, 3, and 6). We note that for all the six-F containing molecules, the scattering process for electron energies above 30 eV is indistinguishable. Finally, we report results for calculations of elastic differential cross sections for electron scattering from each of these isomers, within an optical potential method and assuming a screened corrected independent atom representation. The level of agreement between these calculations and our measurements is found to be quite remarkable in all cases.
Exact Description of Rotational Waves in an Elastic Solid
R. A. Close
2010-12-03
Conventional descriptions of transverse waves in an elastic solid are limited by an assumption of infinitesimally small gradients of rotation. By assuming a linear response to variations in orientation, we derive an exact description of a restricted class of rotational waves in an ideal isotropic elastic solid. The result is a nonlinear equation expressed in terms of Dirac bispinors. This result provides a simple classical interpretation of relativistic quantum mechanical dynamics. We construct a Lagrangian of the form L=-E+U+K=0, where E is the total energy, U is the potential energy, and K is the kinetic energy.
Investigating Energy-Saving Potentials in the Cloud
Lee, Da-Sheng
2014-01-01
Collecting webpage messages can serve as a sensor for investigating the energy-saving potential of buildings. Focusing on stores, a cloud sensor system is developed to collect data and determine their energy-saving potential. The owner of a store under investigation must register online, report the store address, area, and the customer ID number on the electric meter. The cloud sensor system automatically surveys the energy usage records by connecting to the power company website and calculating the energy use index (EUI) of the store. Other data includes the chain store check, company capital, location price, and the influence of weather conditions on the store; even the exposure frequency of store under investigation may impact the energy usage collected online. After collecting data from numerous stores, a multi-dimensional data array is constructed to determine energy-saving potential by identifying stores with similarity conditions. Similarity conditions refer to analyzed results that indicate that two stores have similar capital, business scale, weather conditions, and exposure frequency on web. Calculating the EUI difference or pure technical efficiency of stores, the energy-saving potential is determined. In this study, a real case study is performed. An 8-dimensional (8D) data array is constructed by surveying web data related to 67 stores. Then, this study investigated the savings potential of the 33 stores, using a site visit, and employed the cloud sensor system to determine the saving potential. The case study results show good agreement between the data obtained by the site visit and the cloud investigation, with errors within 4.17%. Among 33 the samples, eight stores have low saving potentials of less than 5%. The developed sensor on the cloud successfully identifies them as having low saving potential and avoids wasting money on the site visit. PMID:24561405
Investigating energy-saving potentials in the cloud.
Lee, Da-Sheng
2014-01-01
Collecting webpage messages can serve as a sensor for investigating the energy-saving potential of buildings. Focusing on stores, a cloud sensor system is developed to collect data and determine their energy-saving potential. The owner of a store under investigation must register online, report the store address, area, and the customer ID number on the electric meter. The cloud sensor system automatically surveys the energy usage records by connecting to the power company website and calculating the energy use index (EUI) of the store. Other data includes the chain store check, company capital, location price, and the influence of weather conditions on the store; even the exposure frequency of store under investigation may impact the energy usage collected online. After collecting data from numerous stores, a multi-dimensional data array is constructed to determine energy-saving potential by identifying stores with similarity conditions. Similarity conditions refer to analyzed results that indicate that two stores have similar capital, business scale, weather conditions, and exposure frequency on web. Calculating the EUI difference or pure technical efficiency of stores, the energy-saving potential is determined. In this study, a real case study is performed. An 8-dimensional (8D) data array is constructed by surveying web data related to 67 stores. Then, this study investigated the savings potential of the 33 stores, using a site visit, and employed the cloud sensor system to determine the saving potential. The case study results show good agreement between the data obtained by the site visit and the cloud investigation, with errors within 4.17%. Among 33 the samples, eight stores have low saving potentials of less than 5%. The developed sensor on the cloud successfully identifies them as having low saving potential and avoids wasting money on the site visit. PMID:24561405
NASA Astrophysics Data System (ADS)
Liu, L.; Wu, X. Z.; Wang, R.; Feng, H. F.; Wu, S.
2012-07-01
The elastic properties and the generalized-stacking-fault-energy (GSFE) in MeO (Me = Mg, Ca) under different pressures have been calculated using the first principle calculations. In the anisotropic elasticity theory approximation, by using the Foreman's method, the core structure and Peierls stress of
Biomass energy: the scale of the potential resource
scale, potential above-ground plant growth on these abandoned lands has an energy content representing resources and decrease food security. The net effect of biomass energy agriculture on climate could. The first is conversion technology and the prospects for using new plant and microbe varieties as well
Brazilian waste potential: energy, environmental, social and economic benefits
Luciano Basto Oliveira; Luiz Pinguelli Rosa
2003-01-01
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
Geospatial Analysis of Renewable Energy Technical Potential on Tribal Lands
Doris, E.; Lopez, A.; Beckley, D.
2013-02-01
This technical report uses an established geospatial methodology to estimate the technical potential for renewable energy on tribal lands for the purpose of allowing Tribes to prioritize the development of renewable energy resources either for community scale on-tribal land use or for revenue generating electricity sales.
Elastic electron and positron scattering from argon
NASA Astrophysics Data System (ADS)
Stauffer, Allan; McEachran, Robert
2008-10-01
In order to obtain accurate elastic differential cross sections for electron and positron scattering from the noble gases at intermediate energies, the effect of the open inelastic channels must be taken into account. We have developed a complex optical potential which does this [1] and have applied this to scattering from argon. Detailed results will be shown. [1] S. Chen, R.P. McEachran and A.D. Stauffer, J. Phys. B 41, 025201 (2008).
DoD energy vulnerabilities: potential problems and observations
Freiwald, D A; Berger, M E; Roach, J F
1982-08-01
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.
Potentials in Energy Momentum Tensor and the Equation of State
Ying-Qiu Gu
2009-01-21
The energy momentum tensor of the perfect fluid is a simplified but successful model of wide practical use in astrophysics. In the previous researches, some important information such as the self-energy of the interaction of the particles and influence of the gravitational potential are usually ignored or introduced phenomenologically. In this letter, the analysis and calculation show that, the interactive potentials of the particles can be described by introducing an extra potential $W$, which acts like negative pressure. For the gases in a star, the state functions are strongly influenced by the gravitational potential, and only the temperature $T$ is independent variable, but the other state functions such as mass-energy density $\\rho$ and pressure $P$ can be expressed as simple functions of $T$. These relations can provide some new insights into the dynamical behavior and structure of a star.
The potential energy surface of Li+–CO
Stephen T. Grice; Peter W. Harland; Robert G. A. R. Maclagan
1993-01-01
A new potential energy surface for the Li+–CO system calculated at the HF\\/6-311+G(2df) and MP4SDTQ\\/6-311+G(2df) levels of theory in a rigid rotor approximation is presented. The potential energy surface has an absolute energy minimum at ?=0°, and R=5.330 bohr of ?0.716 eV. There is also a minimum at ?=180° and R=5.344 bohr of ?0.475 eV, and a col at ?=87.2°
Potential production of energy cane for fuel in the Caribbean
Samuels, G.
1984-08-01
Sugarcane grown as energy cane presents a new potential to the Caribbean countries to provide their own energy needs and to reduce or eliminate fuel oil imports. The use of proper agronomic techniques can convert conventional sugarcane growing to a crop capable of giving energy feedstocks in the form of fiber for boiler fuel for electricity and fermentable solids for alcohol for motor fuel. Sugarcane can still be obtained from the energy cane for domestic consumption and export if desired. The aerable land now devoted to sugarcane can utilized for energy-cane production without causing any serious imbalance in food crop production.
Black hole : Equipartition of matter and potential energy
Naresh Dadhich
1997-05-14
Black hole horizon is usually defined as the limit for existence of timelike worldline or when a spatially bound surface turns oneway (it is crossable only in one direction). It would be insightful and physically appealing to find its characterization involving an energy consideration. By employing the Brown-York [1] quasilocal energy we propose a new and novel characterization of the horizon of static black hole. It is the surface at which the Brown-York energy equipartitions itself between the matter and potential energy. It is also equivalent to equipartitioning of the binding energy and the gravitational charge enclosed by the horizon.
Zorko, A.; Kokalj, J.; Komelj, M.; Adamopoulos, O.; Luetkens, H.; Ar?on, D.; Lappas, A.
2015-01-01
Inhomogeneity in the ground state is an intriguing, emergent phenomenon in magnetism. Recently, it has been observed in the magnetostructural channel of the geometrically frustrated ?-NaMnO2, for the first time in the absence of active charge degrees of freedom. Here we report an in-depth numerical and local-probe experimental study of the isostructural sister compound CuMnO2 that emphasizes and provides an explanation for the crucial differences between the two systems. The experimentally verified, much more homogeneous, ground state of the stoichiometric CuMnO2 is attributed to the reduced magnetoelastic competition between the counteracting magnetic-exchange and elastic-energy contributions. The comparison of the two systems additionally highlights the role of disorder and allows the understanding of the puzzling phenomenon of phase separation in uniform antiferromagnets. PMID:25786810
NASA Astrophysics Data System (ADS)
Xu, Hai-Bo; Zheng, Na
2015-07-01
A version of Geant4 has been developed to treat high-energy proton radiography. This article presents the results of calculations simulating the effects of nuclear elastic scattering for various test step wedges. Comparisons with experimental data are also presented. The traditional expressions of the transmission should be correct if the angle distribution of the scattering is Gaussian multiple Coulomb scattering. The mean free path (which depends on the collimator angle) and the radiation length are treated as empirical parameters, according to transmission as a function of thickness obtained by simulations. The results can be used in density reconstruction, which depends on the transmission expressions. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)
Chung, Le Xuan; Khoa, Dao T; Egelhof, Peter
2015-01-01
The Glauber model analysis of the elastic $^{6,8}$He+$p$ scattering data at energies around 700 MeV/nucleon, measured in two separate experiments at GSI-Darmstadt, has been done using several phenomenological parametrizations of the nuclear matter density. By taking into account the new data points measured at the high momentum transfer, the nuclear matter radii of $^{6,8}$He were accurately determined from the Glauber model analysis of the data, with the spin-orbital interaction explicitly taken into account. The well-known geometry for the core and dineutron halo has been used with the new parametrizations of the $^{6}$He density to extract the detailed information on the structure of $^{6}$He in terms of the core and dineutron halo radii. An enhanced sensitivity of the data measured at the high momentum transfer to the core part of the $^{6,8}$He densities has been found.
Le Xuan Chung; Oleg A. Kiselev; Dao T. Khoa; Peter Egelhof
2015-08-31
The Glauber model analysis of the elastic $^{6,8}$He+$p$ scattering data at energies around 700 MeV/nucleon, measured in two separate experiments at GSI-Darmstadt, has been done using several phenomenological parametrizations of the nuclear matter density. By taking into account the new data points measured at the high momentum transfer, the nuclear matter radii of $^{6,8}$He were accurately determined from the Glauber model analysis of the data, with the spin-orbital interaction explicitly taken into account. The well-known geometry for the core and dineutron halo has been used with the new parametrizations of the $^{6}$He density to extract the detailed information on the structure of $^{6}$He in terms of the core and dineutron halo radii. An enhanced sensitivity of the data measured at the high momentum transfer to the core part of the $^{6,8}$He densities has been found.
NASA Astrophysics Data System (ADS)
Zorko, A.; Kokalj, J.; Komelj, M.; Adamopoulos, O.; Luetkens, H.; Ar?on, D.; Lappas, A.
2015-03-01
Inhomogeneity in the ground state is an intriguing, emergent phenomenon in magnetism. Recently, it has been observed in the magnetostructural channel of the geometrically frustrated ?-NaMnO2, for the first time in the absence of active charge degrees of freedom. Here we report an in-depth numerical and local-probe experimental study of the isostructural sister compound CuMnO2 that emphasizes and provides an explanation for the crucial differences between the two systems. The experimentally verified, much more homogeneous, ground state of the stoichiometric CuMnO2 is attributed to the reduced magnetoelastic competition between the counteracting magnetic-exchange and elastic-energy contributions. The comparison of the two systems additionally highlights the role of disorder and allows the understanding of the puzzling phenomenon of phase separation in uniform antiferromagnets.
NASA Astrophysics Data System (ADS)
Hussey, Martyn; Murray, Andrew; MacGillivray, William; King, George
2008-03-01
Super-elastic scattering processes can be considered as the 'time reversal' of electron-photon coincidence measurements, with the advantage that data are accumulated thousands of times faster. This allows a far more extensive and accurate study of electron excitation of atoms which can also be excited using laser radiation. The application of a newly invented magnetic angle changing (MAC) device to these experiments has allowed the complete scattering geometry to be accessed for the first time, and experimental methods adopted in these new experiments are discussed here. Data are presented for excitation of the 41P1 state of calcium by electron impact at scattering angles from near 0° to beyond 180°, with incident energies of 45 eV and 55 eV. The results are compared to the DWBA theory of Stauffer and colleagues, with generally excellent agreement.
Potential Energy Calculations for Water Adsorption on Poly (methyl methacrylate)
NASA Astrophysics Data System (ADS)
Zuba, Mateusz J.; Howard, Patrick; Familo, Brian; Kane, Thorin; Netusil, Ross L.; Ilie, Carolina C.
2015-03-01
The generosity of the NOYCE Research Grant enabled me to focus on the study of various polymers. The main goal was to study the molecular orbitals of poly (methyl methacrylate) (PMMA) and calculate the energy band gap. We also performed the potential energy calculations for our system: two polymer chains and water molecules. We obtained the activation energy from thermal desorption spectra of water on poly (methyl methacrylate) by employing Arrhenius analysis. NSF - Noyce Scholarship Program.
Renewable energy potential in Bulgaria - Some computer simulations results
NASA Astrophysics Data System (ADS)
Ganev, K.; Jordanov, G.; Gadzhev, G.; Miloshev, N.; Syrakov, D.; Prodanova, M.
2014-11-01
The paper presents a work, which aims at numerical study of the wind and solar energy potential of the country. The wind/solar energy fields simulations were performed applying the 5th generation PSU/NCAR Meso-Meteorological Model MM5 for years 2000-2007 with a spatial resolution of 3 km over Bulgaria. The computer simulated data base is large and rather comprehensive. In this sense it can be considered as statistically significant ensemble. This allows statistical treatment in order various wind and solar energy potential evaluations to be retrieved from the data base. Some evaluations of the country wind and solar energy potential, based on the simulation output are demonstrated in the paper.
On the nuclear interaction. Potential, binding energy and fusion reaction
I. Casinos
2008-05-22
The nuclear interaction is responsible for keeping neutrons and protons joined in an atomic nucleus. Phenomenological nuclear potentials, fitted to experimental data, allow one to know about the nuclear behaviour with more or less success where quantum mechanics is hard to be used. A nuclear potential is suggested and an expression for the potential energy of two nuclear entities, either nuclei or nucleons, is developed. In order to estimate parameters in this expression, some nucleon additions to nuclei are considered and a model is suggested as a guide of the addition process. Coulomb barrier and energy for the addition of a proton to each one of several nuclei are estimated by taking into account both the nuclear and electrostatic components of energy. Studies on the binding energies of several nuclei and on the fusion reaction of two nuclei are carried out.
Electrical energy and cost savings potential at DOD facilities
Konopacki, S.; Akbari, H.; Lister, L.; DeBaille, L.
1996-06-01
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.
Lachlan J. Smith; Nicola L. Fazzalari
2009-01-01
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
Evaluating potential employment effects of community energy programs
Tschanz, J.F.
1985-01-01
Energy planning in a number of communities includes the examination of public actions that lead to energy conservation in all local sectors. A major goal of such comprehensive energy programs is to insulate the local economy from the effects of higher prices for energy from outside the community. Through conservation and the use of locally available resources, and energy management program would reduce the drain on the local economy because of ''imported'' fuels and would benefit from the dollars retained locally in increased economic activity and employment. This paper examines the estimates, made by five communities during energy planning projects, of dollars retained locally and potential employment effects. Each community included a variety of energy management options within its project, ranging from simple, inexpensive retrofit improvements in individual structures to technologically sophisticated community energy supply systems.
Energy potential of municipal solid waste is limited
1994-09-01
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.
A. I. Boothroyd; J. E. Dove; W. J. Keogh; P. G. Martin; M. R. Peterson
1991-01-01
The interaction potential energy surface (PES) of Hâ is of great importance for quantum chemistry, as a test case for molecule--molecule interactions. It is also required for a detailed understanding of certain astrophysical processes, namely, collisional excitation and dissociation of Hâ in molecular clouds, at densities too low to be accessible experimentally. Accurate {ital ab} {ital initio} energies were computed
Arnold I. Boothroyd; John E. Dove; William J. Keogh; Peter G. Martin; Michael R. Peterson
1991-01-01
The interaction potential energy surface (PES) of H4 is of great importance for quantum chemistry, as a test case for molecule–molecule interactions. It is also required for a detailed understanding of certain astrophysical processes, namely, collisional excitation and dissociation of H2 in molecular clouds, at densities too low to be accessible experimentally. Accurate abinitio energies were computed for 6046 conformations
Split kinetic energy method for quantum systems with competing potentials
Mineo, H.; Chao, Sheng D., E-mail: sdchao@spring.iam.ntu.edu.tw
2012-09-15
For quantum systems with competing potentials, the conventional perturbation theory often yields an asymptotic series and the subsequent numerical outcome becomes uncertain. To tackle such a kind of problems, we develop a general solution scheme based on a new energy dissection idea. Instead of dividing the potential energy into 'unperturbed' and 'perturbed' terms, a partition of the kinetic energy is performed. By distributing the kinetic energy term in part into each individual potential, the Hamiltonian can be expressed as the sum of the subsystem Hamiltonians with respective competing potentials. The total wavefunction is expanded by using a linear combination of the basis sets of respective subsystem Hamiltonians. We first illustrate the solution procedure using a simple system consisting of a particle under the action of double {delta}-function potentials. Next, this method is applied to the prototype systems of a charged harmonic oscillator in strong magnetic field and the hydrogen molecule ion. Compared with the usual perturbation approach, this new scheme converges much faster to the exact solutions for both eigenvalues and eigenfunctions. When properly extended, this new solution scheme can be very useful for dealing with strongly coupling quantum systems. - Highlights: Black-Right-Pointing-Pointer A new basis set expansion method is proposed. Black-Right-Pointing-Pointer Split kinetic energy method is proposed to solve quantum eigenvalue problems. Black-Right-Pointing-Pointer Significant improvement has been obtained in converging to exact results. Black-Right-Pointing-Pointer Extension of such methods is promising and discussed.
Potential for energy conservation in the glass industry
Garrett-Price, B.A.; Fassbender, A.G.; Bruno, G.A.
1986-06-01
While the glass industry (flat glass, container glass, pressed and blown glass, and insulation fiber glass) has reduced its specific energy use (Btu/ton) by almost 30% since 1972, significant potential for further reduction still remains. State-of-the-art technologies are available which could lead to incremental improvements in glass industry energy productivity; however, these technologies must compete for capital with projects undertaken for other reasons (e.g., capacity expansion, equipment rebuild, labor cost reduction, product quality improvement, or compliance with environmental, health or safety regulations). Narrowing profit margins in the large tonnage segments of the glass industry in recent years and the fact that energy costs represent less than 25% of the value added in glass manufacture have combined to impede the widespread adoption of many state-of-the-art conservation technologies. Savings in energy costs alone have not provided the incentive to justify the capital expenditures required to realize the energy savings. Beyond implementation of state-of-the-art technologies, significant potential energy savings could accrue from advanced technologies which represent a radical departure from current glass making technology. Long-term research and development (R and D) programs, which address the technical and economic barriers associated with advanced, energy-conserving technologies, offer the opportunity to realize this energy-saving potential.
NASA Astrophysics Data System (ADS)
Kato, H.; Suga, A.; Hoshino, M.; Blanco, F.; García, G.; Limão-Vieira, P.; Brunger, M. J.; Tanaka, H.
2012-04-01
We report absolute differential cross sections (DCSs) for elastic electron scattering from 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.
Energy Consumption and Potential for Energy Conservation in the Steel Industry
Hughes, M. L.
1979-01-01
era specific energy consumption exhibited a steady decline of slightly less than 1 percent per year. Potential for future savings is estimated at approximately 25 percent. Full realization of potential savings will require huge sums of capital...
Gao-Chan Yong
2010-12-13
Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model and the scaling model according to nucleon effective mass, effects of elastic and inelastic NN scattering cross sections on pion-/pion+ in the neutron-rich reaction of Ca48+Ca48 at a beam energy of 400 MeV/nucleon are studied. It is found that cross-section effects of both NN elastic and inelastic scatterings affect Delta_1232, pion- and pion+ production, as well as the value of pion-/pion+.
Yong Gaochan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)
2010-12-15
Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model and the scaling model according to nucleon effective mass, effects of elastic and inelastic NN scattering cross sections on {pi}{sup -}/{pi}{sup +} in the neutron-rich reaction of {sup 48}Ca+{sup 48}Ca at a beam energy of 400 MeV/nucleon are studied. It is found that cross-section effects of both NN elastic and inelastic scatterings affect {Delta}{sub 1232}, {pi}{sup -} and {pi}{sup +} production, as well as the value of {pi}{sup -}/{pi}{sup +}.
Solar energy in California industry - Applications, characteristics and potential
NASA Technical Reports Server (NTRS)
Barbieri, R. H.; Pivirotto, D. S.
1978-01-01
Results of a survey to determine the potential applicability of solar thermal energy to industrial processes in California are presented. It is found that if the heat for all industrial processes at temperatures below 212 F were supplied by solar energy, total state energy consumption could be reduced by 100 trillion Btus (2%), while the use of solar energy in processes between 212 and 350 F could displace 500 trillion Btus. The issues and problems with which solar energy must contend are illustrated by a description of fluid milk processing operations. Solar energy application is found to be technically feasible for processes with thermal energy requirements below 212 F, with design, and degree of technical, economic and management feasibility being site specific. It is recommended that the state provide support for federal and industrial research, development and demonstration programs in order to stimulate acceptance of solar process heat application by industry.
Ab initio potential energy surface and rovibrational energies of Ar . . . CO
Seokmin Shin; Seung Koo Shin; Fu-Ming Tao
1996-01-01
The potential energy surface for the Ar...CO van der Waals complex is calculated by the supermolecular approach using fourth-order Mo&slash;ller–Plesset perturbation theory (MP4) with a large basis set containing bond functions. The Hartree–Fock potentials are repulsive for all configurations considered. The second-order correlation energy accounts for most of the dispersion interactions. The MP4 potential energy surface is characterized by a
The Long Range Gravitational Potential Energy Between Strings
Margaret E. Wessling; Mark B. Wise
2001-10-25
We calculate the gravitational potential energy between infinitely long parallel strings with tensions \\tau_1 and \\tau_2. Classically, it vanishes, but at one loop, we find that the long range gravitational potential energy per unit length is U/L = 24G_N^2\\tau_1\\tau_2/(5 \\pi a^2) + ..., where a is the separation between the strings, G_N is Newton's constant, and we set \\hbar = c =1. The ellipses represent terms suppressed by more powers of G_N \\tau_i. Typically, massless bulk fields give rise at one loop to a long range potential between p-branes in space-times of dimension p+2+1. The contribution to this potential from bulk scalars is computed for arbitrary p (strings correspond to p=1) and in the case of three-branes its possible relevance for cosmological quintessence is commented on.
Saturation wind power potential and its implications for wind energy.
Jacobson, Mark Z; Archer, Cristina L
2012-09-25
Wind turbines convert kinetic to electrical energy, which returns to the atmosphere as heat to regenerate some potential and kinetic energy. As the number of wind turbines increases over large geographic regions, power extraction first increases linearly, but then converges to a saturation potential not identified previously from physical principles or turbine properties. These saturation potentials are >250 terawatts (TW) at 100 m globally, approximately 80 TW at 100 m over land plus coastal ocean outside Antarctica, and approximately 380 TW at 10 km in the jet streams. Thus, there is no fundamental barrier to obtaining half (approximately 5.75 TW) or several times the world's all-purpose power from wind in a 2030 clean-energy economy. PMID:23019353
Reconstructing Dark Energy Potentials From Parameterized Deceleration Parameters
Wang, Yuting; Lu, Jianbo; Gui, Yuan-Xing
2010-01-01
In this paper, the properties of dark energy are investigated according to the parameterized deceleration parameter $q(z)$, which is used to describe the extent of the accelerating expansion of the universe. The potential of dark energy $V(\\phi)$ and the cosmological parameters, such as the dimensionless energy density $\\Omega_{\\phi}$, $\\Omega_{m}$, and the state parameter $w_\\phi$, are connected to it. Concretely, by giving two kinds of parameterized deceleration parameters $q(z)=a+\\frac{bz}{1+z}$ and $q(z)=1/2+\\frac{az+b}{(1+z)^2}$, the evolution of these parameters and the reconstructed potentials $V(\\phi)$ are plotted and analyzed. It's found that the potentials run away with the evolution of universe.
Saturation wind power potential and its implications for wind energy
Jacobson, Mark Z.; Archer, Cristina L.
2012-01-01
Wind turbines convert kinetic to electrical energy, which returns to the atmosphere as heat to regenerate some potential and kinetic energy. As the number of wind turbines increases over large geographic regions, power extraction first increases linearly, but then converges to a saturation potential not identified previously from physical principles or turbine properties. These saturation potentials are >250 terawatts (TW) at 100 m globally, approximately 80 TW at 100 m over land plus coastal ocean outside Antarctica, and approximately 380 TW at 10 km in the jet streams. Thus, there is no fundamental barrier to obtaining half (approximately 5.75 TW) or several times the world’s all-purpose power from wind in a 2030 clean-energy economy. PMID:23019353
Collisionless Plasma Modeling in an Arbitrary Potential Energy Distribution
NASA Technical Reports Server (NTRS)
Liemohn, M. W.; Khazanov, G. V.
1997-01-01
A new technique for calculating a collisionless plasma along a field line is presented. The primary feature of the new model is that it can handle an arbitrary (including nonmonotonic) potential energy distribution. This was one of the limiting constraints on the existing models in this class, and these constraints are generalized for an arbitrary potential energy composition. The formulation for relating current density to the field-aligned potential as well as formulas for density, temperature and energy flux calculations are presented for several distribution functions, ranging from a bi-Lorentzian with a loss cone to an isotropic Maxwellian. A comparison of these results with previous models shows that the formulation reduces.to the earlier models under similar assumptions.
Full-folding-model description of elastic scattering at intermediate energies
Arellano, H. F.; Brieva, F. A.; Love, W. G.
1989-08-07
Nucleon-nucleus optical potentials are calculated using full off-shell nucleon-nucleon free /ital t/ matrices based on the Paris potential. Applications to proton scattering from /sup 40/Ca at 200 and 300 MeV are presented. Significant differences are found between observables calculated using full-folding potentials and /ital t//rho/ approximations to them, demonstrating the importance of an accurate treatment of off-shell effects. The agreement between calculated and measured observables improves substantially using the full-folding model.
Predicting surface free energies with interatomic potentials and electron counting
D A Murdick; X W Zhou; H N G Wadley; D Nguyen-Manh
2005-01-01
Current interatomic potentials for compound semiconductors, such as GaAs, fail to correctly predict the ab initio calculated and experimentally observed surface reconstructions.These potentials do not address the electron occupancies of dangling bonds associated with surface atoms and their well established role in the formation of low-energy surfaces. The electron counting rule helps account for the electron distribution among covalent and
Low-energy potential scattering in two and three dimensions
N. N. Khuri; Andre Martin; Jean-Marc Richard; Tai Tsun Wu
2009-06-10
Conditions are established for the existence of a scattering length and an effective range in the low-energy expansion of the S-wave phase-shift of a central potential in two and three dimensions. The behavior of the phase-shift as a function of the momentum is also derived for longer-range power-law potentials which do not fulfill these conditions.
Role of energy dependent interaction potential in sub-barrier fusion of S2814i +Z9040r system
NASA Astrophysics Data System (ADS)
Gautam, Manjeet Singh; Sharma, Manoj K.
2015-08-01
We have analyzed the importance of the inelastic surface vibrations of colliding nuclei in the sub-barrier fusion enhancement of S2814i +Z9040r system by using the energy dependent Woods-Saxon potential model (EDWSP model) in conjunction with one dimensional Wong formula and the coupled channel formulation using the code CCFULL. The multi-phonon vibrational states of colliding nuclei seem to impart significant contribution. The coupling between relative motion of reactants and these relevant channels in turn produce anomalously large sub-barrier fusion enhancement over the expectations of one dimensional barrier penetration model. Furthermore, the effects of coupling to inelastic surface excitations are imitated due to energy dependence in the Woods-Saxon potential. In EDWSP model calculations, a wide range of diffuseness parameter much larger than the elastic scattering predictions is needed to account the observed fusion enhancement in the close vicinity of Coulomb barrier.
Direct Reconstruction of the Dark Energy Scalar-Field Potential
Chao Li; Daniel E. Holz; Asantha Cooray
2006-11-28
While the accelerated expansion of the Universe is by now well established, an underlying scalar field potential possibly responsible for this acceleration remains unconstrained. We present an attempt to reconstruct this potential using recent SN data, under the assumption that the acceleration is driven by a single scalar field. Current approaches to such reconstructions are based upon simple parametric descriptions of either the luminosity distance or the dark energy equation of state. We find that these various approximations lead to a range of derived evolutionary histories of the dark energy equation of state (although there is considerable overlap between the different potential shapes allowed by the data). Instead of these indirect reconstruction schemes, we discuss a technique to determine the potential directly from the data by expressing it in terms of a binned scalar field. We apply this technique to a recent SN dataset, and compare the results with model-dependent approaches. In a similar fashion to direct estimates of the dark energy equation of state, we advocate direct reconstruction of the scalar field potential as a way to minimize prior assumptions on the shape, and thus minimize the introduction of bias in the derived potential.
Soft diffraction and the elastic slope at Tevatron and LHC energies: a multi-Pomeron approach
V. A. Khoze; A. D. Martin; M. G. Ryskina
2000-01-01
. 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
Wayside energy storage for recuperation of potential energy from freight trains
Lawson, L.J.; Koper, J.; Cook, L.M.
1981-01-01
The subject of this paper, involves the potential for use of a wayside energy storage system to recapture part of the braking energy normally dissipated on long descending grades by freight trains employing dynamic braking. 4 refs.
NASA Astrophysics Data System (ADS)
Manning, Gerald S.
2015-09-01
We give a contemporary and direct derivation of a classical, but insufficiently familiar, result in the theory of linear elasticity—a representation for the energy of a stressed elastic rod with central axis that intrinsically takes the shape of a general space curve. We show that the geometric torsion of the space curve, while playing a crucial role in the bending energy, is physically unrelated to the elastic twist. We prove that the twist energy vanishes in the lowest-energy states of a rod subject to constraints that do not restrict the twist. The stretching and contraction energies of a free helical spring are computed. There are local high-energy minima. We show the possibility of using the spring to model the chirality of DNA. We then compare our results with an available atomic level energy simulation that was performed on DNA unconstrained in the same sense as the free spring. We find some possible reflections of springlike behavior in the mechanics of DNA, but, unsurprisingly, the base pairs lend a material substance to the core of DNA that a spring does not capture.
Manning, Gerald S
2015-09-14
We give a contemporary and direct derivation of a classical, but insufficiently familiar, result in the theory of linear elasticity-a representation for the energy of a stressed elastic rod with central axis that intrinsically takes the shape of a general space curve. We show that the geometric torsion of the space curve, while playing a crucial role in the bending energy, is physically unrelated to the elastic twist. We prove that the twist energy vanishes in the lowest-energy states of a rod subject to constraints that do not restrict the twist. The stretching and contraction energies of a free helical spring are computed. There are local high-energy minima. We show the possibility of using the spring to model the chirality of DNA. We then compare our results with an available atomic level energy simulation that was performed on DNA unconstrained in the same sense as the free spring. We find some possible reflections of springlike behavior in the mechanics of DNA, but, unsurprisingly, the base pairs lend a material substance to the core of DNA that a spring does not capture. PMID:26374056
Potentials for energy efficiency improvement in the US cement industry
Ernst Worrell; Nathan Martin; Lynn Price
2000-01-01
This paper reports on an in-depth analysis of the US cement industry, identifying cost-effective energy efficiency measures and potentials. Between 1970 and 1997, primary physical energy intensity for cement production (SIC 324) dropped 30%, from 7.9 GJ\\/t to 5.6 GJ\\/t, while specific carbon dioxide emissions due to fuel consumption and clinker calcination dropped 17%, from 0.29 tC\\/tonne to 0.24 tC\\/tonne.
Feet on the potential energy surface, head in the ? clouds
Quentin Anthony Smith
2011-01-01
The landscape of a potential energy surface is marked by chemically interesting features. Hills and valleys correspond to transition states and reactive intermediates; the deepest valley gives the most stable configuration. Mapping these features for individual molecules and for the interactions between molecules is one of the goals of computational chemistry.\\u000aThe dispersion energy is a weak attractive force in
Potential structural material problems in a hydrogen energy system
NASA Technical Reports Server (NTRS)
Gray, H. R.; Nelson, H. G.; Johnson, R. E.; Mcpherson, B.; Howard, F. S.; Swisher, J. H.
1975-01-01
Potential structural material problems that may be encountered in the three components of a hydrogen energy system - production, transmission/storage, and utilization - were identified. Hydrogen embrittlement, corrosion, oxidation, and erosion may occur during the production of hydrogen. Hydrogen embrittlement is of major concern during both transmission and utilization of hydrogen. Specific materials research and development programs necessary to support a hydrogen energy system are described.
Reaction Path Optimization with Holonomic Constraints and Kinetic Energy Potentials
Brokaw, Jason B.; Haas, Kevin R.; Chu, Jhih-wei
2009-08-11
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 identify pathways whose energy barriers are consistent with experimental measurements. Further, we develop a method based on the work energy theorem to quantify the accuracy of reaction paths and to determine whether the atoms used to define a path are enough to provide quantitative estimation of energy barriers.
Adaptive Energy Saving Scheme for Downlink Elastic Traffic in Wireless Networks
Bahk, Saewoong
is defined as inversely proportional to the weighted multiplication of service completion time and energy. By periodically waking up and checking whether there is a packet to receive, the MS can save a huge amount until the MS wakes up again, which incurs an additional delay. To balance between delay and energy
Wang,W.; Yang, L.; Huang, H.
2007-01-01
Recent experiments suggested that cholesterol and other lipid components of high negative spontaneous curvature facilitate membrane fusion. This is taken as evidence supporting the stalk-pore model of membrane fusion in which the lipid bilayers go through intermediate structures of high curvature. How do the high-curvature lipid components lower the free energy of the curved structure? Do the high-curvature lipid components modify the average spontaneous curvature of the relevant monolayer, thereby facilitate its bending, or do the lipid components redistribute in the curved structure so as to lower the free energy? This question is fundamental to the curvature elastic energy for lipid mixtures. Here we investigate the lipid distribution in a monolayer of a binary lipid mixture before and after bending, or more precisely in the lamellar, hexagonal, and distorted hexagonal phases. The lipid mixture is composed of 2:1 ratio of brominated di18:0PC and cholesterol. Using a newly developed procedure for the multiwavelength anomalous diffraction method, we are able to isolate the bromine distribution and reconstruct the electron density distribution of the lipid mixture in the three phases. We found that the lipid distribution is homogenous and uniform in the lamellar and hexagonal phases. But in the distorted hexagonal phase, the lipid monolayer has nonuniform curvature, and cholesterol almost entirely concentrates in the high curvature region. This finding demonstrates that the association energies between lipid molecules vary with the curvature of membrane. Thus, lipid components in a mixture may redistribute under conditions of nonuniform curvature, such as in the stalk structure. In such cases, the spontaneous curvature depends on the local lipid composition and the free energy minimum is determined by lipid distribution as well as curvature.
Baram, J.; Avissar, J.; Gefen, Y.; Rosen, M.
1980-05-01
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.
Energy Policy 32 (2004) 289297 The potential of solar electric power for meeting future US energy
Delaware, University of
2004-01-01
Energy Policy 32 (2004) 289297 The potential of solar electric power for meeting future US energy of solar electric power in the form of photovoltaics to meet future US energy demand with the projected needs: a comparison of projections of solar electric energy generation and Arctic National Wildlife
Evaluating the Energy Saving Potential and Cost-Effectiveness of Industrial Energy Efficiency by Kristan Boudreau Based on the original research of Rob Lockhart of the Energy Research Group Simon Fraser University March 2000 #12;Energy Research Group i March 2000 Table of Contents 1 INTRODUCTION
Theory of orientational elasticity
S. Stallinga; G. Vertogen
1994-01-01
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
O. A. Rojas-Gómez; J. M. Romero-Enrique
2012-05-18
In this paper we present a generalization of Berreman's model for the elastic contribution to the surface free-energy density of a nematic liquid crystal in presence of a sawtooth substrate which favours homeotropic anchoring, as a function of the wavenumber of the surface structure $q$, the tilt angle $\\alpha$ and the surface anchoring strength $w$. In addition to the previously reported non-analytic contribution proportional to $q\\ln q$, due to the nucleation of disclination lines at the wedge bottoms and apexes of the substrate, the next-to-leading contribution is proportional to $q$ for a given substrate roughness, in agreement with Berreman's predictions. We characterise this term, finding that it has two contributions: the deviations of the nematic director field with respect to the corresponding to the isolated disclination lines, and their associated core free energies. Comparison with the results obtained from the Landau-de Gennes model shows that our model is quite accurate in the limit $wL>1$, when strong anchoring conditions are effectively achieved.
Analysis of energy dissipation and deposition in elastic bodies impacting at hypervelocities
NASA Technical Reports Server (NTRS)
Medina, David F.; Allahdadi, Firooz A.
1992-01-01
A series of impact problems were analyzed using the Eulerian hydrocode CTH. The objective was to quantify the amount of energy dissipated locally by a projectile-infinite plate impact. A series of six impact problems were formulated such that the mass and speed of each projectile were varied in order to allow for increasing speed with constant kinetic energy. The properties and dimensions of the plate were the same for each projectile impact. The resulting response of the plate was analyzed for global Kinetic Energy, global momentum, and local maximum shear stress. The percentage of energy dissipated by the various hypervelocity impact phenomena appears as a relative change of shear stress at a point away from the impact in the plate.
Framework for State-Level Renewable Energy Market Potential Studies
Claire Kreycik; Laura Vimmerstedt; Elizabeth Doris
2010-01-01
State-level policymakers are relying on estimates of the market potential for renewable energy resources as they set goals and develop policies to accelerate the development of these resources. Therefore, accuracy of such estimates should be understood and possibly improved to appropriately support these decisions. This document provides a framework and next steps for state officials who require estimates of renewable
Morse potential energy spectra through the variational method and supersymmetry
NASA Astrophysics Data System (ADS)
Filho, Elso Drigo; Ricotta, Regina Maria
2000-05-01
The Variational Method is applied within the context of Supersymmetric Quantum Mechanics to provide information about the energy and eigenfunction of the lowest levels of a Hamiltonian. The approach is illustrated by the case of the Morse potential applied to several diatomic molecules and the results are compared with stabilished results.
Teaching Field Concept and Potential Energy at A-Level.
ERIC Educational Resources Information Center
Poon, C. H.
1986-01-01
Argues for a greater emphasis on the reality of fields in electronics and gravitation instruction. Advocates that the potential energy in a system be regarded as stored in the field rather than in the material bodies of the system. Provides a rationale and examples for this position. (ML)
Bound energy for the exponential-cosine-screened Coulomb potential
Sameer M. Ikhdair; Ramazan Sever
2006-04-11
An alternative approximation scheme has been used in solving the Schrodinger equation for the exponential-cosine-screened Coulomb potential. The bound state energ\\i es for various eigenstates and the corresponding wave functions are obtained analytically up to the second perturbation term.
Low energy chiral two pion exchange potential with statistical uncertainties
R. Navarro Perez; J. E. Amaro; E. Ruiz Arriola
2015-05-12
We present a new phenomenological Nucleon-Nucleon chiral potential fitted to 925 pp and 1743 np scattering data selected from the Granada-2013 NN-database up to a laboratory energy of $125$ MeV with 20 short distance parameters and three chiral constants $c_1$, $c_3$ and $c_4$ with $\\chi^2/\
Frequency Domain Solution of a Piezo-aero-elastic Wing for Energy Harvesting
Wander Gustavo Rocha Vieira; Carlos Marqui Junior; Alper Erturk; Daniel J. Inman
\\u000a Multifunctional structures are pointed out as a future breakthrough technology for Unmanned Air Vehicle (UAV) design. These\\u000a structures can perform tasks additional to their primary functions. Based on the concept of vibration-based energy harvesting,\\u000a the structure (lifting surfaces) of a UAV can perform the additional function of providing electrical energy by converting\\u000a aeroelastic vibrations to electricity. In this paper, frequency-domain
LHC Physics Potential vs. Energy: Considerations for the 2011 Run
Quigg, Chris; /Fermilab /CERN
2011-02-01
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I quantify the advantage of increasing the beam energy from 3.5 TeV to 4 TeV. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u {bar d}, qq, and gq interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes. This note extends the analysis presented in Ref. [1]. Full-size figures are available as pdf files at lutece.fnal.gov/PartonLum11/.
Manning, G S
1985-09-01
The equilibrium trajectory of the axis of a rod subject to an externally imposed curved potential energy trough tends to conform to the shape of the curved trough, but also tends to be straight because of elastic resistance to bending. The actual path of the axis is a balance between the two extremes. We consider a potential energy trough centered along a circular arc of radius R. For a rod of small length compared to R, we show that the axis at equilibrium forms an arc of a circle of radius greater than R. The value of the radius of the axial path depends on the relative values of the Hooke's Law bending constant for the rod and the depth and width of the trough. Motivation for the calculation is provided by nucleosomal DNA, which conforms to the surface of a roughly cylindrical histone core at physiological ionic strength, but is observed to unwind into a partially extended conformation at very low ionic strength. We suggest that the rigidity to bending of short DNA segments becomes sufficiently great at low ionic strength to overcome attractive interactions with the histone surface. Alternately, of course, if during the cell cycle mutually attractive forces between DNA and histone core are weakened at constant ionic strength, the same type of unfolding would be expected to occur as the strength of the DNA-histone contacts drops below the level required to overcome elastic resistance to bending of the DNA rod. PMID:2416444
Electron-Hydrogen Elastic Scattering
NASA Technical Reports Server (NTRS)
Bhatia, A. K.
2004-01-01
Scattering by single-electron systems is always of interest because the wave function of the target is known exactly. Various approximations have been employed to take into account distortion produced in the target. Among them are the method of polarized orbitals and the close coupling approximation. Recently, e-H and e-He+ S-wave scattering in the elastic region has been studied using the Feshbach projection operator formalism. In this approach, the usual Hartree-Fock and exchange potentials are augmented by an optical potential and the resulting phase shifts have rigorous lower bounds. Now this method is being applied to the e-H P-wave scattering in the elastic region. The number of terms in the Hylleraas-type wave function for the 1,3 P phase shifts is 84 and the resulting phase shifts (preliminary) are given. The results have been given up to five digits because to that accuracy they are rigorous lower bounds. They are in general agreement with the variational (VAR) results of Armstead, and those obtained from the intermediate energy R-matrix method (RM) of Scholz et al., and the finite element method (FEM) of Botero and Shertzer. The later two methods do not provide any bounds on phase shifts.
Renewable energy technologies adoption in Kazakhstan: potentials, barriers and solutions
NASA Astrophysics Data System (ADS)
Karatayev, Marat; Marazza, Diego; Contin, Andrea
2015-04-01
The growth in environmental pollution alongside an increasing demand for electricity in Kazakhstan calls for a higher level of renewable energy penetration into national power systems. Kazakhstan has great potential for renewable energies from wind, solar, hydro and biomass resources that can be exploited for electricity production. In 2013, the Kazakhstani Ministry of Energy initiated a new power development plan, which aims to bring the share of renewable energy to 3% by 2020 rising to 30% by 2030 and 50% by 2050. The current contribution of renewable energy resources in the national electricity mix, however, is less than 1%. As a developing country, Kazakhstan has faced a number of barriers to increase renewable energy use, which have to be analysed and translated into a comprehensive renewable energy policy framework. This study presents an overview of the current conditions of renewable energy development in Kazakhstan. Secondly, it identifies and describes the main barriers that prevent diffusion of renewable energy technologies in Kazakhstan. Finally, the paper provides solutions to overcome specific barriers in order to successfully develop a renewable energy technology sector in Kazakhstan.
Global Potential of Energy Efficiency Standards and Labeling Programs
McNeil, Michael A; McNeil, Michael A.; Letschert, Virginie; de la Rue du Can, Stephane
2008-06-15
This report estimates the global potential reductions in greenhouse gas emissions by 2030 for energy efficiency improvements associated with equipment (appliances, lighting, and HVAC) in buildings by means of energy efficiency standards and labels (EES&L). A consensus has emerged among the world's scientists and many corporate and political leaders regarding the need to address the threat of climate change through emissions mitigation and adaptation. A further consensus has emerged that a central component of these strategies must be focused around energy, which is the primary generator of greenhouse gas emissions. Two important questions result from this consensus: 'what kinds of policies encourage the appropriate transformation to energy efficiency' and 'how much impact can these policies have'? This report aims to contribute to the dialogue surrounding these issues by considering the potential impacts of a single policy type, applied on a global scale. The policy addressed in this report is Energy Efficient Standards and Labeling (EES&L) for energy-consuming equipment, which has now been implemented in over 60 countries. Mandatory energy performance standards are important because they contribute positively to a nation's economy and provide relative certainty about the outcome (both timing and magnitudes). Labels also contribute positively to a nation's economy and importantly increase the awareness of the energy-consuming public. Other policies not analyzed here (utility incentives, tax credits) are complimentary to standards and labels and also contribute in significant ways to reducing greenhouse gas emissions. We believe the analysis reported here to be the first systematic attempt to evaluate the potential of savings from EES&L for all countries and for such a large set of products. The goal of the analysis is to provide an assessment that is sufficiently well-quantified and accurate to allow comparison and integration with other strategies under consideration.
Understanding Potential Climate Variability Impacts on the Offshore Energy Industry
NASA Astrophysics Data System (ADS)
Stear, J.
2014-12-01
Climate variability may have important implications for the offshore energy industry. Scenarios of increased storm activity and changes in sea level could require the retrofit of existing offshore platforms and coastal infrastructure, the decommissioning of facilities for which upgrade or relocation is not economically viable, and the development of new methods and equipment which are removed from or less sensitive to environmental loads. Over the past years the energy industry has been actively involved in collaborative research efforts with government and academia to identify the potential changes in the offshore operating environment, and corresponding risk implications. This presentation will review several of these efforts, and for several of the hypothetical climate variation scenarios, review the potential impacts on and possible mitigations for offshore and coastal energy infrastructure and operations.
Three-dimensional potential energy surface of Ar-CO.
Sumiyoshi, Yoshihiro; Endo, Yasuki
2015-01-14
A three-dimensional intermolecular potential energy surface of the Ar-CO complex has been determined by fitting most of the previously reported spectroscopic data, where observed transition frequencies by microwave, millimeter-wave, submillimeter-wave, and infrared spectroscopy were reproduced simultaneously within their experimental accuracies. A free rotor model Hamiltonian considering all the freedom of motions for an atom-diatom system was applied to calculate vibration-rotation energies. A three-dimensional potential energy surface obtained by ab initio calculations at the CCSD(T)-F12b/aug-cc-pV5Z level of theory was parameterized by a model function consisting of 46 parameters. They were used as initial values for the least-squares analysis of the experimental data. A total of 20 parameters were optimized to reproduce all the spectroscopic data. PMID:25591360
Potential Energy Functions for Metal Clusters and Nanoparticles
NASA Astrophysics Data System (ADS)
Legenski, Nicole; Forrey, Robert C.; Cheng, Hansong
2010-03-01
Atomic force fields for simulating copper, silver, and gold clusters and nanoparticles are developed. Potential energy functions are obtained for each metallic system using an embedded atom method with parameters that have an explicit dependence on coordination number. Many cluster configurations of varying size and shape are used to constrain the parametrization for each system. Binding energies for these training clusters were computed using density functional theory (DFT) with the Perdew-Wang exchange-correlation functional in the generalized gradients approximation. Extensive testing shows that the many-body potentials are able to reproduce the DFT energies for most of the near-equilibrium and many of the non-equilibrium structures that were included in the training set. Implications for molecular dynamics simulations and extensions to binary metallic systems and also to hydrogen on metallic clusters are discussed.
How Deep is the Antinucleon Optical Potential at FAIR energies
T. Gaitanos; M. Kaskulov; H. Lenske
2011-08-11
The key question in the interaction of antinucleons in the nuclear medium concerns the deepness of the antinucleon-nucleus optical potential. In this work we study this task in the framework of the non-linear derivative (NLD) model which describes consistently bulk properties of nuclear matter and Dirac phenomenology of nucleon-nucleus interactions. We apply the NLD model to antinucleon interactions in nuclear matter and find a strong decrease of the vector and scalar self-energies in energy and density and thus a strong suppression of the optical potential at zero momentum and, in particular, at FAIR energies. This is in agreement with available empirical information and, therefore, resolves the issue concerning the incompatibility of G-parity arguments in relativistic mean-field (RMF) models. We conclude the relevance of our results for the future activities at FAIR.
Turkey's High Temperature Geothermal Energy Resources and Electricity Production Potential
NASA Astrophysics Data System (ADS)
Bilgin, Ö.
2012-04-01
Turkey is in the first 7 countries in the world in terms of potential and applications. Geothermal energy which is an alternative energy resource has advantages such as low-cost, clean, safe and natural resource. Geothermal energy is defined as hot water and steam which is formed by heat that accumulated in various depths of the Earth's crust; with more than 20oC temperature and which contain more than fused minerals, various salts and gases than normal underground and ground water. It is divided into three groups as low, medium and high temperature. High-temperature fluid is used in electricity generation, low and medium temperature fluids are used in greenhouses, houses, airport runways, animal farms and places such as swimming pools heating. In this study high temperature geothermal fields in Turkey which is suitable for electricity production, properties and electricity production potential was investigated.
The Potential Role of Fusion Energy in China and India
NASA Astrophysics Data System (ADS)
Sheffield, John
2004-11-01
It is projected that both China and India will install many 100's of megawatts electric (MWe) of additional electrical capacity by 2050 with more additions later. All energy resources will be required to meet such a demand. Fortunately, while world energy demand will be increasing, the world is well endowed with a variety of energy resources. However, their distribution does not match well the areas of demand and there are many environmental issues. Such geopolitical issues affect China and India and make it important for them to be able to deploy improved technologies. International collaborations in developing these technologies, such as the International Thermonuclear Experimental Reactor (ITER), may be important in all energy areas. In this regard, Korea is an interesting example of a country that has worked with other countries to develop its own capability to do advanced technologies - such as nuclear fission plants - in a relatively short time. Fusion energy is viewed as interesting potential option in these three countries.
Regional Differences in the Price-Elasticity of Demand for Energy
Bernstein, M. A.; Griffin, J.
2006-02-01
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 different levels of data resolution. In this case, RAND compares national, regional, state, and electric utility levels of data resolution. This study is intended as a first step in helping NREL understand the impact that spatial disaggregation of data can have on estimating the impacts of their programs. This report should be useful to analysts in NREL and other national laboratories, as well as to policy nationals at the national level. It may help them understand the complex relationships between demand and price and how these might vary across different locations in the United States.
Stored elastic energy powers the 60-?m extension of the Limulus polyphemus sperm actin bundle
Shin, Jennifer H.; Mahadevan, L.; Waller, Guillermina S.; Langsetmo, Knut; Matsudaira, Paul
2003-01-01
During the 5 s of the acrosome reaction of Limulus polyphemus sperm, a 60-?m-long bundle of scruin-decorated actin filaments straightens from a coiled conformation and extends from the cell. To identify the motive force for this movement, we examined the possible sources of chemical and mechanical energy and show that the coil releases ?10?13 J of stored mechanical strain energy, whereas chemical energy derived from calcium binding is ?10?15 J. These measurements indicate that the coiled actin bundle extends by a spring-based mechanism, which is distinctly different from the better known polymerization or myosin-driven processes, and that calcium initiates but does not power the reaction. PMID:14517201
NASA Astrophysics Data System (ADS)
Mladenov, I. M.; Marinov, P. I.; Hadzhilazova, M. Ts.
2014-11-01
In the present article we extend previous results on the elastic Sturmian spirals. We use a relation between the infinitesimal angle of inclination and the infinitesimal polar radius in this particular set up. New parametrizations are given in terms of the polar radius a nd the angle of inclination, all in closed form. Plots of the relevant cases are presented as well.
Potentials and policy implications of energy and material efficiency improvement
Worrell, Ernst; Levine, Mark; Price, Lynn; Martin, Nathan; van den Broek, Richard; Block, Kornelis
1997-01-01
There is a growing awareness of the serious problems associated with the provision of sufficient energy to meet human needs and to fuel economic growth world-wide. This has pointed to the need for energy and material efficiency, which would reduce air, water and thermal pollution, as well as waste production. Increasing energy and material efficiency also have the benefits of increased employment, improved balance of imports and exports, increased security of energy supply, and adopting environmentally advantageous energy supply. A large potential exists for energy savings through energy and material efficiency improvements. Technologies are not now, nor will they be, in the foreseeable future, the limiting factors with regard to continuing energy efficiency improvements. There are serious barriers to energy efficiency improvement, including unwillingness to invest, lack of available and accessible information, economic disincentives and organizational barriers. A wide range of policy instruments, as well as innovative approaches have been tried in some countries in order to achieve the desired energy efficiency approaches. These include: regulation and guidelines; economic instruments and incentives; voluntary agreements and actions, information, education and training; and research, development and demonstration. An area that requires particular attention is that of improved international co-operation to develop policy instruments and technologies to meet the needs of developing countries. Material efficiency has not received the attention that it deserves. Consequently, there is a dearth of data on the qualities and quantities for final consumption, thus, making it difficult to formulate policies. Available data, however, suggest that there is a large potential for improved use of many materials in industrialized countries.
Elastic scattering and transfer reactions for the system 7Be + 58Ni at Coulomb barrier energies
NASA Astrophysics Data System (ADS)
Mazzocco, M.; Torresi, D.; Acosta, L.; Boiano, A.; Boiano, C.; Glodariu, T.; Guglielmetti, A.; Keeley, N.; La Commara, M.; Lay, J. A.; Martel, I.; Mazzocchi, C.; Molini, P.; Parascandolo, C.; Parkar, V. V.; Pierroutsakou, D.; Romoli, M.; Rusek, K.; Sanchez-Benitez, A. M.; Sandoli, M.; Signorini, C.; Silvestri, R.; Soramel, F.; Strano, E.; Stroe, L.
2015-09-01
We investigated the reaction induced by the Radioactive Ion Beam 7Be on the closed proton shell nucleus 58Ni at 22.0 MeV bombarding energy. The 7Be beam was produced by means of the in-flight technique with the facility EXOTIC at INFN-LNL (Italy). Charged reaction products were mass and charge identified in a rather wide angular range and their energy distributions were analyzed to infer some information on the production mechanism. The relevance of direct processes, especially 3He- and 4He-stripping, as well as compound nucleus reactions is critically reviewed.
Reexamination of the energy levels of 15F by 14O+1H elastic resonance scattering
NASA Astrophysics Data System (ADS)
Guo, F. Q.; Powell, J.; Lee, D. W.; Leitner, D.; McMahan, M. A.; Moltz, D. M.; O'Neil, J. P.; Perajarvi, K.; Phair, L.; Ramsey, C. A.; Xu, X. J.; Cerny, Joseph
2005-09-01
The energy levels of 15F have been measured by the p(14O,p)14O reaction. The 120 MeV 14O radioactive ion beam was produced by the BEARS coupled cyclotron system at an intensity averaging 1×104 particles/second on target. Energy calibration was obtained using resonances from the p(14N,p)14N reaction. The two lowest resonances in 15F were fitted with an R-matrix calculation. The fit to the ground state had J?=1/2+ at 1.23 ± 0.05 MeV (width 0.5 - 0.84 MeV), and the first excited state was J?=5/2+ at 2.81 ± 0.02 MeV (width 0.30 ± 0.06 MeV), both relative to the mass-energy of the proton and 14O. The 15F ground state energy supports the disappearance of the Z = 8 proton magic number for odd Z,Tz=-3/2 nuclei.
U.S. Building-Sector Energy Efficiency Potential
Brown, Rich; Borgeson, Sam; Koomey, Jon; Biermayer, Peter
2008-09-30
This paper presents an estimate of the potential for energy efficiency improvements in the U.S. building sector by 2030. The analysis uses the Energy Information Administration's AEO 2007 Reference Case as a business-as-usual (BAU) scenario, and applies percentage savings estimates by end use drawn from several prior efficiency potential studies. These prior studies include the U.S. Department of Energy's Scenarios for a Clean Energy Future (CEF) study and a recent study of natural gas savings potential in New York state. For a few end uses for which savings estimates are not readily available, the LBNL study team compiled technical data to estimate savings percentages and costs of conserved energy. The analysis shows that for electricity use in buildings, approximately one-third of the BAU consumption can be saved at a cost of conserved energy of 2.7 cents/kWh (all values in 2007 dollars), while for natural gas approximately the same percentage savings is possible at a cost of between 2.5 and 6.9 $/million Btu. This cost-effective level of savings results in national annual energy bill savings in 2030 of nearly $170 billion. To achieve these savings, the cumulative capital investment needed between 2010 and 2030 is about $440 billion, which translates to a 2-1/2 year simple payback period, or savings over the life of the measures that are nearly 3.5 times larger than the investment required (i.e., a benefit-cost ratio of 3.5).
Mathews, David H; Case, David A
2006-04-14
The nudged elastic band (NEB) technique has been implemented in AMBER to calculate low-energy paths for conformational changes. A novel simulated annealing protocol that does not require an initial hypothesis for the path is used to sample low-energy paths. This was used to study the conformational change of an RNA cis Watson-Crick/Hoogsteen GG non-canonical pair, with one G syn around the glycosidic bond and the other anti. A previous solution structure, determined by NMR-constrained modeling, demonstrated that the GG pairs change from (syn)G-(anti)G to (anti)G-(syn)G in the context of duplex r(GCAGGCGUGC) on the millisecond timescale. The set of low-energy paths found by NEB show that each G flips independently around the glycosidic bond, with the anti G flipping to syn first. Guanine bases flip without opening adjacent base-pairs by protruding into the major groove, accommodated by a transient change by the ribose to C2'-exo sugar pucker. Hydrogen bonds between bases and the backbone, which lower the energetic barrier to flipping, are observed along the path. The results show the plasticity of RNA base-pairs in helices, which is important for biological processes, including mismatch repair, protein recognition, and translation. The modeling of the GG conformational change also demonstrates that NEB can be used to discover non-trivial paths for macromolecules and therefore NEB can be used as an exploratory method for predicting putative conformational change paths. PMID:16487974
A three-dimensional He-NaH potential energy surface for rovibrational energy transfer studies
Brian K. Taylor
2004-01-01
A three-dimensional potential energy surface for the He-NaH van der Waals complex is calculated at the coupled cluster singles-and-doubles with noniterative inclusion of connected triples [CCSD(T)] level of theory. Estimates of CCSD(T) interaction energies for an infinitely large basis set is obtained using a basis set extrapolation scheme. The He-NaH potential energy surface is much different than the He-LiH surface.
Evaluation of global onshore wind energy potential and generation costs.
Zhou, Yuyu; Luckow, Patrick; Smith, Steven J; Clarke, Leon
2012-07-17
In this study, we develop an updated global estimate of onshore wind energy potential using reanalysis wind speed data, along with updated wind turbine technology performance, land suitability factors, cost assumptions, and explicit consideration of transmission distance in the calculation of transmission costs. We find that wind has the potential to supply a significant portion of the world energy needs, although this potential varies substantially by region and with assumptions such as on what types of land can be used to site wind farms. Total global economic wind potential under central assumptions, that is, intermediate between optimistic and pessimistic, is estimated to be approximately 119.5 petawatt hours per year (13.6 TW) at less than 9 cents/kWh. A sensitivity analysis of eight key parameters is presented. Wind potential is sensitive to a number of input parameters, particularly wind speed (varying by -70% to +450% at less than 9 cents/kWh), land suitability (by -55% to +25%), turbine density (by -60% to +80%), and cost and financing options (by -20% to +200%), many of which have important policy implications. As a result of sensitivities studied here we suggest that further research intended to inform wind supply curve development focus not purely on physical science, such as better resolved wind maps, but also on these less well-defined factors, such as land-suitability, that will also have an impact on the long-term role of wind power. PMID:22715929
A generalization of CAPE into potential-energy convertibility
NASA Astrophysics Data System (ADS)
Yano, Jun-Ichi; Chaboureau, Jean-Pierre; Guichard, Françoise
2005-04-01
The concept of the potential-energy convertibility (PEC) is proposed as a generalization of convective available potential energy (CAPE). It is defined as a vertical integral of buoyancy weighted by a non-dimensional normalized vertical momentum. This is a measure of convertibility of potential energy into kinetic energy in the sense that the actual conversion rate is recovered when PEC evaluated by the convective-scale local buoyancy and vertical momentum, as available from cloud-resolving model (CRM) simulations, is multiplied by the normalization factor for the vertical momentum. It reduces to CAPE, when the standard parcel-lifted buoyancy and a unit value for the normalized vertical momentum are used. It is equivalent to Arakawas-Schubert's cloud work function, when the buoyancy and the vertical momentum profile for an entraining plume are used. PEC evaluated from locally defined buoyancy and vertical momentum in CRM simulations correlates better with the convective precipitation than CAPE. The evaluation of PEC within a convective parametrization may be possible with an appropriate definition of the effective entrainment rate, for example, which is expected to improve CAPE-based convective parametrizations.
Nonlinear elasticity of biological tissues with statistical fibre orientation
Federico, Salvatore; Gasser, T. Christian
2010-01-01
The elastic strain energy potential for nonlinear fibre-reinforced materials is customarily obtained by superposition of the potentials of the matrix and of each family of fibres. Composites with statistically oriented fibres, such as biological tissues, can be seen as being reinforced by a continuous infinity of fibre families, the orientation of which can be represented by means of a probability density function defined on the unit sphere (i.e. the solid angle). In this case, the superposition procedure gives rise to an integral form of the elastic potential such that the deformation features in the integral, which therefore cannot be calculated a priori. As a consequence, an analytical use of this potential is impossible. In this paper, we implemented this integral form of the elastic potential into a numerical procedure that evaluates the potential, the stress and the elasticity tensor at each deformation step. The numerical integration over the unit sphere is performed by means of the method of spherical designs, in which the result of the integral is approximated by a suitable sum over a discrete subset of the unit sphere. As an example of application, we modelled the collagen fibre distribution in articular cartilage, and used it in simulating displacement-controlled tests: the unconfined compression of a cylindrical sample and the contact problem in the hip joint. PMID:20053655
A global potential energy surface for ArH2
NASA Technical Reports Server (NTRS)
Schwenke, David W.; Walch, Stephen P.; Taylor, Peter R.
1992-01-01
We describe a simple analytic representation of the ArH2 potential energy surface which well reproduces the results of extensive ab initio electronic structure calculations. The analytic representation smoothly interpolates between the dissociated H2 and strong bonding limits. In the fitting process, emphasis is made on accurately reproducing regions of the potential expected to be important for high temperature (ca. 3000 K) collision processes. Overall, the anisotropy and H2 bond length dependence of the analytic representation well reproduce the input data.
Waves and energy in random elastic guided media through the stochastic wave finite element method
NASA Astrophysics Data System (ADS)
Ben Souf, M. A.; Bareille, O.; Ichchou, M. N.; Bouchoucha, F.; Haddar, M.
2013-11-01
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.
Theoretical study of the elastic breakup of weakly bound nuclei at near barrier energies
D. R. Otomar; P. R. S. Gomes; J. Lubian; L. F. Canto; M. S. Hussein
2015-10-06
We have performed CDCC calculations for collisions of $^{7}$Li projectiles on $^{59}$Co, $^{144}$Sm and $^{208}$Pb targets at near-barrier energies, to assess the importance of the Coulomb and the nuclear couplings in the breakup of $^{7}$Li, as well as the Coulomb-nuclear interference. We have also investigated scaling laws, expressing the dependence of the cross sections on the charge and the mass of the target. This work is complementary to the one previously reported by us on the breakup of $^{6}$Li. Here we explore the similarities and differences between the results for the two Lithium isotopes. The relevance of the Coulomb dipole strength at low energy for the two-cluster projectile is investigated in details.
Theoretical study of the elastic breakup of weakly bound nuclei at near barrier energies
Otomar, D R; Lubian, J; Canto, L F; Hussein, M S
2015-01-01
We have performed CDCC calculations for collisions of $^{7}$Li projectiles on $^{59}$Co, $^{144}$Sm and $^{208}$Pb targets at near-barrier energies, to assess the importance of the Coulomb and the nuclear couplings in the breakup of $^{7}$Li, as well as the Coulomb-nuclear interference. We have also investigated scaling laws, expressing the dependence of the cross sections on the charge and the mass of the target. This work is complementary to the one previously reported by us on the breakup of $^{6}$Li. Here we explore the similarities and differences between the results for the two Lithium isotopes. The relevance of the Coulomb dipole strength at low energy for the two-cluster projectile is investigated in details.
An exploration of the ozone dimer potential energy surface.
Azofra, Luis Miguel; Alkorta, Ibon; Scheiner, Steve
2014-06-28
The (O3)2 dimer potential energy surface is thoroughly explored at the ab initio CCSD(T) computational level. Five minima are characterized with binding energies between 0.35 and 2.24 kcal/mol. The most stable may be characterized as slipped parallel, with the two O3 monomers situated in parallel planes. Partitioning of the interaction energy points to dispersion and exchange as the prime contributors to the stability, with varying contributions from electrostatic energy, which is repulsive in one case. Atoms in Molecules analysis of the wavefunction presents specific O?O bonding interactions, whose number is related to the overall stability of each dimer. All internal vibrational frequencies are shifted to the red by dimerization, particularly the antisymmetric stretching mode whose shift is as high as 111 cm(-1). In addition to the five minima, 11 higher-order stationary points are identified. PMID:24985642
An exploration of the ozone dimer potential energy surface
Azofra, Luis Miguel; Alkorta, Ibon [Instituto de Química Médica, CSIC, Juan de la Cierva 3, E-28006 Madrid (Spain); Scheiner, Steve, E-mail: steve.scheiner@usu.edu [Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300 (United States)
2014-06-28
The (O{sub 3}){sub 2} dimer potential energy surface is thoroughly explored at the ab initio CCSD(T) computational level. Five minima are characterized with binding energies between 0.35 and 2.24 kcal/mol. The most stable may be characterized as slipped parallel, with the two O{sub 3} monomers situated in parallel planes. Partitioning of the interaction energy points to dispersion and exchange as the prime contributors to the stability, with varying contributions from electrostatic energy, which is repulsive in one case. Atoms in Molecules analysis of the wavefunction presents specific O?O bonding interactions, whose number is related to the overall stability of each dimer. All internal vibrational frequencies are shifted to the red by dimerization, particularly the antisymmetric stretching mode whose shift is as high as 111 cm{sup ?1}. In addition to the five minima, 11 higher-order stationary points are identified.
NASA Astrophysics Data System (ADS)
Ghazvini, M.; Salehi, N.; Hassanabadi, H.; A. Rajabi, A.
2015-06-01
In this paper, the Schrödinger equation for a 6-body system is studied. We solve this equation for the lithium nucleus by using a supersymmetry method with several specific potentials. These potentials are the Yukawa potential, the generalized Yukawa potential and the Hellmann potential. The results of our model for all calculations show that the ground state binding energy of the lithium nucleus with these potentials is very close to that obtained experimentally.
Potential for improved energy efficiency to help meet future energy needs
1981-01-01
The estimated technical potential for cost-effective energy conservation is summarized for both the US and California. These estimates should be viewed as theoretical opportunities for improving energy efficiency; they are not necessarily forecasts of the actual savings that might result from government policies and the market's response to higher energy prices. Detailed analyses are offered for residential buildings, using supply
Role of the Clean Energy Potential for Energy Savings and Air Pollution Control in Turkey
KAM?L KAYGUSUZ; HULUS? KARGI ABDULLAH KAYGUSUZ; A. Kaygusuz
1996-01-01
This article begins with a brief review of the technical potential, the regional distribution, and the air pollution effects of all fossil energy sources as well as of all clean and renewable energy sources that could be used in Turkey. Air pollution levels due to fossil fuel consumption are examined. In this context, the role of clean energy sources is
Technical Potential of Solar Energy to Address Energy Poverty and Avoid GHG Emissions in Africa
Cowlin, S. C.; Heimiller, D.; Bilello, D.; Renne, D.
2008-01-01
This analysis explores the technical potential of photovoltaics (PV) or concentrating solar power (CSP) to address energy poverty in Africa through a geographic information system (GIS) screening of solar resource data developed by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL).
Elastic models of the glass transition applied to a liquid with density anomalies
M. Pica Ciamarra; Peter Sollich
2015-08-19
Elastic models of the glass transition relate the relaxation dynamics and the elastic properties of structural glasses. They are based on the assumption that the relaxation dynamics occurs through activated events in the energy landscape whose energy scale is set by the elasticity of the material. Here we investigate whether such elastic models describe the relaxation dynamics of systems of particles interacting via a purely repulsive harmonic potential, focusing on a volume fraction and temperature range that is characterized by entropy--driven water--like density anomalies. We do find clear correlations between relaxation time and diffusivity on the one hand, and plateau shear modulus and Debye--Waller factor on the other, thus supporting the validity of elastic models of the glass transition. However, we also show that the plateau shear modulus is not related to the features of the underlying energy landscape of the system, at variance with recent results for power--law potentials. This challenges the common potential energy landscape interpretation of elastic models.
Search for dark energy potentials in quintessence theory
Muromachi, Yusuke; Okada, Daiki; Hara, Tetsuya; Itoh, Yutaka
2015-01-01
The time evolution of the equation of state $w$ for quintessence models with a scalar field as dark energy is studied up to the third derivative ($d^3w/da^3$) with respect to scale factor $a$, in order to predict the future observations and specify the scalar potential parameters with the observables. The third derivative of $w$ for general potential $V$ was derived and applied to several types of potential. They are the inverse power-law ($V=M^{4+\\alpha}/Q^{\\alpha}$), exponential ($V=M^4\\exp{(\\beta M/Q)}$), mixed ( $V=M^{4+\\gamma}\\exp{(\\beta M/Q)}/Q^{\\gamma}$), cosine ($V=M^4(\\cos (Q/f)+1)$) and the Gaussian types ($V=M^4\\exp(-Q^2/\\sigma^2)$), which are prototypical potentials for the freezing and thawing models. If the parameter number for a potential form is $ n$, it is necessary to find at least for $n+2$ independent observations to identify the potential form and the evolution of scalar field ($Q$ and $ \\dot{Q} $). Such observations would be the values of $ \\Omega_Q, w, dw/da. \\cdots $, and $ dw^n/da^n$....
Figueira, J. M.; Arazi, A.; Carnelli, P.; Heimann, D. Martinez; Negri, A. E.; Pacheco, A. J.; Niello, J. O. Fernandez; Capurro, O. A.; Fimiani, L.; Marti, G. V.; Lubian, J.; Monteiro, D. S.; Gomes, P. R. S.
2010-02-15
Angular distributions for the elastic scattering of the weakly bound {sup 6,7}Li+{sup 144}Sm systems were measured with high accuracy at bombarding energies from 85% up to 170% of the Coulomb barrier. An optical model analysis was performed, and the relevant parameters of the real and imaginary parts of the optical potential were extracted. The results are compared with those previously published for the tightly bound {sup 12}C+{sup 144}Sm and {sup 16}O+{sup 144}Sm systems. The usual threshold anomaly observed in the behavior of the potential of tightly bound systems was not observed for either weakly bound system. This absence is attributed to the repulsion due to breakup coupling which cancels the attraction arising from couplings with bound channels.
Anderson, Daniel M; Benson, James D; Kearsley, Anthony J
2014-12-01
Mathematical modeling plays an enormously important role in understanding the behavior of cells, tissues, and organs undergoing cryopreservation. Uses of these models range from explanation of phenomena, exploration of potential theories of damage or success, development of equipment, and refinement of optimal cryopreservation/cryoablation strategies. Over the last half century there has been a considerable amount of work in bio-heat and mass-transport, and these models and theories have been readily and repeatedly applied to cryobiology with much success. However, there are significant gaps between experimental and theoretical results that suggest missing links in models. One source for these potential gaps is that cryobiology is at the intersection of several very challenging aspects of transport theory: it couples multi-component, moving boundary, multiphase solutions that interact through a semipermeable elastic membrane with multicomponent solutions in a second time-varying domain, during a two-hundred Kelvin temperature change with multi-molar concentration gradients and multi-atmosphere pressure changes. In order to better identify potential sources of error, and to point to future directions in modeling and experimental research, we present a three part series to build from first principles a theory of coupled heat and mass transport in cryobiological systems accounting for all of these effects. The hope of this series is that by presenting and justifying all steps, conclusions may be made about the importance of key assumptions, perhaps pointing to areas of future research or model development, but importantly, lending weight to standard simplification arguments that are often made in heat and mass transport. In this first part, we review concentration variable relationships, their impact on choices for Gibbs energy models, and their impact on chemical potentials. PMID:25240602
Parallel unconstrained minimization of potential energy in LAMMPS
Plantenga, T.
1997-10-13
This report describes a new minimization capability added to LAMMPS V4.0. Minimization of potential energy is used to find molecular conformations that are close to structures found in nature. The new minimization algorithm uses LAMMPS subroutines for calculating energy and force vectors, and follows the LAMMPS partitioning scheme for distributing large data objects on multiprocessor machines. Since gradient-based algorithms cannot tolerate nonsmoothness, a new Coulomb style that smoothly cuts off to zero at a finite distance is provided. This report explains the minimization algorithm and its parallel implementation within LAMMPS. Guidelines are given for invoking the algorithm and interpreting results.
No strings attached potential vs. interaction energy in QCD
Goldman, T.
1996-10-20
In infrared-stable fixed-point field theories, the interaction energy of a test particle is proportional to the non-relativistic (heavy source) coordinate-space potential derived from the field strength produced by that source. This is no longer true in ultraviolet-stable fixed-point field theories (UVSFPFT) as they may not have a finite infrared fixed point. This leads to the possibility that UVSFPFTs may have quite conventional field strength distributions despite the unusual spatial dependence expected for the interaction energy.
Do we understand near-forward elastic scattering up to TeV energies?
Bourrely, Claude; Wu, Tai Tsun
2015-01-01
In 1970, on purely theoretical grounds, all total hadronic total cross sections were predicted to increase without limit for higher and higher energies. This was contrary to the conventional belief at that time. In 1978, an accurate phenomeno- logical model was formulated for the case of proton-proton and antiproton-proton interactions. The parameters for this model were slightly improved in 1984 using the additional available experimental data. Since then, for thirty years these param- eters have not changed. This development, including especially the difficult task of formulating this phenomenological model and the comparison of the predictions of this model with later experimental results, is summarized.
Computed rotational rainbows from realistic potential energy surfaces
Gianturco, F.A.; Palma, A.
1985-08-01
The quantal IOS approximation in here employed to study interference structures in the rotationally inelastic, state-to-state differential cross sections for polar diatomic targets (LiH, FH, and CO) interacting with He atoms. Quite realistic expressions are used to describe the relevant potential energy surfaces (PES) which were taken from previous works that tested them against accurate experimental findings for total and partial differential cross sections. Specific features like short-range anisotropy and well depth, long-range attractive regions and overall range of action for each potential employed are analyzed and discussed in relation to their influence on rotational rainbows appearance and on the possible observation of cross section extrema in rotational energy distributions.
Potential-energy surfaces for excited states in extended systems
A. Hellman; B. Razaznejad; B. I. Lundqvist
2004-01-01
With a simple and physically intuitive method, first-principles calculations of potential-energy surfaces are performed for excited states in a number of illustrative systems, including dimers (H2 and NaCl) and gas-surface systems [Cl-Na(100) and Cl2-Na(100)]. It is based on density-functional theory and is a generalization of the Delta self-consistent field (DeltaSCF) method, where electron-hole pairs are introduced in order to model
An ab initio potential energy surface for Ne–CO
George C. McBane; Slawomir M. Cybulski
1999-01-01
A new ab initio two-dimensional potential energy surface for the Ne–CO interaction is described. The surface was obtained by the supermolecule method at the CCSD(T) level of theory. It is compared with several experimental data sets and with the symmetry-adapted perturbation theory (SAPT) surface of Moszynski &etal; [J. Phys. Chem. A 101, 4690 (1997)]. The new surface gives modestly better
An ab initio potential energy surface for NeCO
George C. McBane; Slawomir M. Cybulski
1999-01-01
A new ab initio two-dimensional potential energy surface for the Ne-CO interaction is described. The surface was obtained by the supermolecule method at the CCSD(T) level of theory. It is compared with several experimental data sets and with the symmetry-adapted perturbation theory (SAPT) surface of Moszynski et al. [J. Phys. Chem. A 101, 4690 (1997)]. The new surface gives modestly
Pitcher, E.J.; Ferguson, P.D.; Russell, G.J.; Prael, R.E.; Madland, D.G.; Court, J.D.; Daemen, L.L.; Wechsler, M.S.
1997-10-01
The latest release of the medium-energy Monte Carlo transport code LAHET includes a new nucleon-nucleus elastic scattering treatment based on a global medium-energy phenomenological optical-model potential. Implementation of this new model in LAHET allows nuclear elastic scattering for neutrons with energies greater than 15 MeV and for protons with energies greater than 50 MeV. Previous investigations on the impact of the new elastic scattering data revealed that the addition of the proton elastic scattering channel can lead to a significant increase in the calculated damage energy under certain conditions. The authors report here results on the impact of the new elastic scattering data on calculated displacement cross sections in various elements for neutrons with energies in the range 16 to 3,160 MeV. Calculated displacement cross sections at 20 MeV in low-mass materials are in better agreement with SPECTER-calculated cross sections.
Available potential energy in the world's oceans by Rui Xin Huang1
Huang, Rui Xin
that in the case with bottom topography, the available gravitational potential energy cannot be represented is the total available potential energy which is defined as the sum of available gravitational potential energy and realistic topography. It is estimated that the world's oceans available gravitational potential energy
Broughton, S. Allen
Introduction Basic Structure Symmetries Labelling and Potential Energy Future Work Geometry from by NSF Award DMR-0304487 #12;Introduction Basic Structure Symmetries Labelling and Potential Energy and Potential Energy local potential energy terms 5 Future Work #12;Introduction Basic Structure Symmetries
Potential for luminosity improvement for low-energy RHIC operation
Fedotov A. V.
2012-05-20
At the Brookhaven National Laboratory, a physics program, motivated by the search of the QCD phase transition critical point, requires operation of the Relativistic Heavy Ion Collider (RHIC) with heavy ions at very low beam energies corresponding to 2.5-20 GeV/n. Several physics runs were already successfully performed at these low energies. However, the luminosity is very low at lowest energies of interest (< 10 GeV/n) limited by the intra-beam scattering and space-charge, as well as by machine nonlinearities. At these low energies, electron cooling could be very effective in counteracting luminosity degradation due to the IBS, while it is less effective against other limitations. Overall potential luminosity improvement for low-energy RHIC operation from cooling is summarized for various energies, taking into account all these limitations as well as beam lifetime measured during the low-energy RHIC runs. We also explore a possibility of further luminosity improvement under the space-charge limitation.
Evaluation of Global Onshore Wind Energy Potential and Generation Costs
Zhou, Yuyu; Luckow, Patrick; Smith, Steven J.; Clarke, Leon E.
2012-06-20
In this study, we develop an updated global estimate of onshore wind energy potential using reanalysis wind speed data, along with updated wind turbine technology performance and cost assumptions as well as explicit consideration of transmission distance in the calculation of transmission costs. We find that wind has the potential to supply a significant portion of world energy needs, although this potential varies substantially by region as well as with assumptions such as on what types of land can be used to site wind farms. Total global wind potential under central assumptions is estimated to be approximately 89 petawatt hours per year at less than 9 cents/kWh with substantial regional variations. One limitation of global wind analyses is that the resolution of current global wind speed reanalysis data can result in an underestimate of high wind areas. A sensitivity analysis of eight key parameters is presented. Wind potential is sensitive to a number of input parameters, particularly those related to land suitability and turbine density as well as cost and financing assumptions which have important policy implications. Transmission cost has a relatively small impact on total wind costs, changing the potential at a given cost by 20-30%. As a result of sensitivities studied here we suggest that further research intended to inform wind supply curve development focus not purely on physical science, such as better resolved wind maps, but also on these less well-defined factors, such as land-suitability, that will also have an impact on the long-term role of wind power.
Intraclass Price Elasticity & Electric Rate Design
Gresham, K. E.
1987-01-01
with customer usage. 'The more energy used by a customer, the'greater the amount of elasticity. For an in dustrial customer, this means that all energy con sumed up to the amount necessary for base operations is relatively inelastic. All energy consumption... beyond this becomes more elastic as usage increases. In the book "Innovative Electric, Rates," John Chamberlin and Charles Dickson utilize an economic model to test conservation programs. This model utilizes intrac1ass price elasticities and has a...
The potential impact of hydrogen energy use on the atmosphere
NASA Astrophysics Data System (ADS)
van Ruijven, B. J.; Lamarque, J. F.; van Vuuren, D. P.; Kram, T.; Eerens, H.
2009-04-01
Energy models show very different trajectories for future energy systems (partly as function of future climate policy). One possible option is a transition towards a hydrogen-based energy system. The potential impact of such hydrogen economy on atmospheric emissions is highly uncertain. On the one hand, application of hydrogen in clean fuel cells reduces emissions of local air pollutants, like SOx and NOx. On the other hand, emissions of hydrogen from system leakages are expected to change the atmospheric concentrations and behaviour (see also Price et al., 2007; Sanderson et al., 2003; Schultz et al., 2003; Tromp et al., 2003). The uncertainty arises from several sources: the expected use of hydrogen, the intensity of leakages and emissions, and the atmospheric chemical behaviour of hydrogen. Existing studies to the potential impacts of a hydrogen economy on the atmosphere mostly use hydrogen emission scenarios that are based on simple assumptions. This research combines two different modelling efforts to explore the range of impacts of hydrogen on atmospheric chemistry. First, the potential role of hydrogen in the global energy system and the related emissions of hydrogen and other air pollutants are derived from the global energy system simulation model TIMER (van Vuuren, 2007). A set of dedicated scenarios on hydrogen technology development explores the most pessimistic and optimistic cases for hydrogen deployment (van Ruijven et al., 2008; van Ruijven et al., 2007). These scenarios are combined with different assumptions on hydrogen emission factors. Second, the emissions from the TIMER model are linked to the NCAR atmospheric model (Lamarque et al., 2005; Lamarque et al., 2008), in order to determine the impacts on atmospheric chemistry. By combining an energy system model and an atmospheric model, we are able to consistently explore the boundaries of both hydrogen use, emissions and impacts on atmospheric chemistry. References: Lamarque, J.-F., Kiehl, J. T., Hess, P. G., Collins, W. D., Emmons, L. K., Ginoux, P., Luo, C. and Tie, X. X. (2005). "Response of a coupled chemistry-climate model to changes in aerosol emissions: Global impact on the hydrological cycle and the tropospheric burdens of OH, ozone and NOx." Geophysical Research Letters 32(16). Lamarque, J.-F., Kinnison, D. E., Hess, P. G. and Vitt, F. (2008). "Simulated lower stratospheric trends between 1970 and 2005: identifying the role of climate and composition changes." Journal of Geophysical Research 113(D12301). Price, H., Jaegle, L., Rice, A., Quay, P., Novelli, P. C. and Gammon, R. (2007). "Global budget of molecular hydrogen and its deuterium content: constraints from ground station, cruise, and aircraft observations." Journal of Geophysical Research 112(D22108). Sanderson, M. G., Collins, W. J., Derwent, R. G. and Johnson, C. E. (2003). "Simulation of Global Hydrogen Levels Using a Lagrangian Three-Dimensional Model." Journal of Atmospheric Chemistry 46(1): 15-28. Schultz, M. G., Diehl, T., Brasseur, G. P. and Zittel, W. (2003). "Air Pollution and Climate-Forcing Impacts of a Global Hydrogen Economy." Science 302(5645): 624-627. Tromp, T. K., Shia, R. L., Allen, M., Eiler, J. M. and Yung, Y. L. (2003). "Potential environmental impact of a hydrogen economy on the stratosphere." Science 300(5626): 1740-1742. van Ruijven, B., Hari, L., van Vuuren, D. P. and de Vries, B. (2008). "The potential role of hydrogen in India and Western Europe." Energy Policy 36(5): 1649-1665. van Ruijven, B., van Vuuren, D. P. and de Vries, B. (2007). "The potential role of hydrogen in energy systems with and without climate policy." International Journal of Hydrogen Energy 32(12): 1655-1672. van Vuuren, D. P. (2007). Energy systems and climate policy. Dept. of Science, Technology and Society, Faculty of Science. Utrecht, Utrecht University: 326.
Sean P. Leary; Steven M. Pilgrim
1999-01-01
Energy conversion efficiency is a critical parameter for all electromechanical materials. Although excellent techniques are available for linear materials, nonlinearities complicate the determination of conversion efficiency in electrostrictive Pb(Mg1\\/3Nb2\\/3 )O3 (PMN). The field dependence of the elastic modulus presents additional problems. A technique combining pulse-echo ultrasound has been developed to approximate the change in the Young's modulus with applied field.
Dapor, M.; Miotello, A.
1998-05-01
The authors present tables of the differential, total, and transport cross sections for the elastic scattering of 500--4000 eV positrons by neutral atoms in the atomic number range Z = 1--92. The cross sections were computed by numerically solving the Dirac equation for a central electrostatic field up to a large radius where the atomic potential becomes negligible. The atomic potential used was Hartree-Fock for Z = 1--18 and Dirac-Hartree-Fock-Slater for Z = 19--92.
Elastic and surface energies: Two key parameters for CdSe quantum dot formation
Robin, Ivan-Christophe; Andre, Regis; Bougerol, Catherine; Aichele, Thomas; Tatarenko, Serge
2006-06-05
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.
Subbiah, A.; Nilsson, L. J.; Larson, E. D.
1995-01-01
KRAFT PULP MILL: POTENTIAL FOR ENERGY EFFICIENCY AND ADVANCED BIOMASS COGENERATION Anand Subbiah Lars 1. Nilsson' Eric D. Larson" Senior Engineer Visiting Research Fellow Research Engineer Synergic Resources Corp. Center for Energy and Center... for Energy and Bala Cynwyd, PA Environmental Studies Environmental Studies Princeton University Princeton University Princeton, NJ ABSTRACT Energy use at a kraft pulp mill in th United States is analyzed in detail. Annual average process steam...
On boundary potential energies in deformational and configurational mechanics
NASA Astrophysics Data System (ADS)
Steinmann, Paul
This contribution deals with the implications of boundary potential energies, i.e. in short surface, curve and point potentials, on deformational and configurational mechanics. Within the realm of deformational mechanics the surface/curve potentials are allowed in the most general case to depend on the deformation, the surface/curve deformation gradient and the spatial surface normal/curve tangent and are parametrised in the material placement and the material surface normal/curve tangent. The point potentials depend on the deformation and are parametrised in the material placement. From the configurational mechanics perspective the roles of fields and parametrisations are reversed. By considering variational arguments based on the kinematics of deforming surfaces/curves, in particular the relevant surface/curve stresses and distributed forces contributing to (localized) deformational and configurational force balances at surfaces/curves/points, which extend the common traction boundary conditions, are derived. Thereby, dissipative distributed configurational forces that are energetically conjugate to configurational changes are introduced as definitions. The (localized) force balances at surfaces/curves/points together with the contributing stresses and distributed forces within deformational and configurational mechanics display an intriguing duality. The resulting dissipative configurational tractions at the boundary are exemplified for some illustrative cases of boundary potentials.
CO dimer: new potential energy surface and rovibrational calculations.
Dawes, Richard; Wang, Xiao-Gang; Carrington, Tucker
2013-08-15
The spectrum of CO dimer was investigated by solving the rovibrational Schrödinger equation on a new potential energy surface constructed from coupled-cluster ab initio points. The Schrödinger equation was solved with a Lanczos algorithm. Several 4D (rigid monomer) global ab initio potential energy surfaces (PESs) were made using a previously reported interpolating moving least-squares (IMLS) fitting procedure specialized to describe the interaction of two linear fragments. The potential has two nonpolar minima giving rise to a complicated set of energy level stacks, which are very sensitive to the shapes and relative depths of the two wells. Although the CO dimer has defied previous attempts at an accurate purely ab initio description our best surface yields results in good agreement with experiment. Root-mean-square (rms) fitting errors of less than 0.1 cm(-1) were obtained for each of the fits using 2226 ab initio data at different levels. This allowed direct assessment of the quality of various levels of ab initio theory for prediction of spectra. Our tests indicate that standard CCSD(T) is slow to converge the interaction energy even when sextuple zeta bases as large as ACV6Z are used. The explicitly correlated CCSD(T)-F12b method was found to recover significantly more correlation energy (from singles and doubles) at the CBS limit. Correlation of the core-electrons was found to be important for this system. The best PES was obtained by extrapolation of calculations at the CCSD(T)(AE)-F12b/CVnZ-F12 (n = 3,4) levels. The calculated energy levels were compared to 105 J ? 10 levels from experiment. The rms error for 68 levels with J ? 6 is only 0.29 cm(-1). The calculated energy levels were assigned stack labels using several tools. New stacks were found. One of them, stack y1, has an energy lower than many previously known stacks and may be observable. PMID:23738948
On the potential energy landscape of supercooled liquids and glasses.
Rodney, D; Schrøder, T
2011-09-01
The activation-relaxation technique (ART), a saddle-point search method, is applied to determine the potential energy landscape around supercooled and glassy configurations of a three-dimensional binary Lennard-Jones system. We show a strong relation between the distribution of activation energies around a given glassy configuration and its history, in particular, the cooling rate used to produce the glass and whether or not the glass was plastically deformed prior to sampling. We also compare the thermally activated transitions found by ART around a supercooled configuration with the succession of transitions undergone by the same supercooled liquid during a time trajectory simulated by molecular dynamics. We find that ART is biased towards more heterogeneous transitions with higher activation energies and more broken bonds than the MD simulation. PMID:21947901