These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

A potential for Th from inversion of cohesive energy: Elastic constants  

NASA Astrophysics Data System (ADS)

An interatomic pair potential for Th was derived by using the Chen-Mobius lattice inversion of cohesive energy for fcc Th as a starting point to develop a free-parameter potential suitable to be used in molecular dynamic calculations for predicting microstructure evolution and thermal properties in multicomponent nuclear fuel. The cohesive energy versus lattice parameter of Th was computed from first principles electronic structure calculations. The elastic constants for fcc Th were calculated by applying different types of strain to the starting crystal. Based on this information, the shear modulus, the Youngs modulus and the Poissons ratio were obtained. The computed elastic constants of fcc Th are found to be in a good agreement with experiments and previous theoretical results.

Jaroszewicz, S.; Mosca, H. O.; Garcés, J. E.

2012-08-01

2

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

E-print Network

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.

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

2012-12-12

3

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

SciTech Connect

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

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

2009-07-15

4

Energy dependence of optical potential in the near barrier elastic scattering of 11B from 232Th  

NASA Astrophysics Data System (ADS)

The elastic scattering cross sections of 11B projectile on the 232Th target have been measured at different bombarding energies close to the Coulomb barrier. The data has been analyzed for this system using the optical model ECIS code with phenomenological Woods-Saxon forms of the optical potentials. The energy dependence of the volume type real and imaginary parts of the optical potentials are derived from the best fit of the experimental angular distribution data. The total reaction cross sections are obtained from optical model analysis.

Dubey, Shradha; Mukherjee, S.; Patel, D.; Gupta, Y. K.; Danu, L. S.; Joshi, B. N.; Prajapati, G. K.; Mukhopadhyay, S.; John, B. V.; Nayak, B. K.; Biswas, D. C.

2015-01-01

5

Influence of surface energy on the elastic compression of nanosphere  

NASA Astrophysics Data System (ADS)

The influence of surface energy on the elastic compression of nanosphere is addressed through the principle of minimum potential energy. By using the displacement potential approach, the elastic field of nanosphere under diametrical compression is derived analytically. Firstly, surface energy induces a uniform pre-existing hydrostatic compression in the entire nanosphere. More importantly, when the ratio of surface energy density to the radius of sphere is comparable with the elastic modulus, the response of nanosphere to external loading will be evidently distinct from the classical prediction. When the compressive load-depth curve is used to calculate the elastic modulus of nanosphere, the presence of surface energy predicts the size dependence of elastic modulus, which enhances significantly as the radius of sphere decreases below 100 nm. This study provides an efficient tool to analyze the elastic deformation of nanoparticles and measure their elastic properties.

Long, J. M.; Qin, X.; Wang, G. F.

2015-02-01

6

Series Elastic Actuation: Potential and Pitfalls  

E-print Network

.G.E.hobbelen@wbmt.tudelft.nl Abstract-- In this paper we explore the space of design freedoms associated with series elastic actuators system. This strategy follows that of animals, who store gait energy in springy tendons[2], [3], [4], [5 of supporting Raibert-style running in addition to a wide variety of other locomotion and contact tasks [6], [7

Hurst, Jonathan

7

The elastic energy of damaged rocks  

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

8

Passive dynamic walking with elastic energy  

Microsoft Academic Search

This paper presents passive dynamic walking with elastic energy. We propose a new type of passive dynamic walking robot. by adding elastic materials such as spring or rubber between a supporting leg and a swing leg of the robot By utilizing restoring force of spring or rubber, we can make the passive dynamic walking robot easily walk since the crotch

Masahiro Mizuno; Hiroshi Ohtake; Kazuo Tanaka; Hua O. Wang

2008-01-01

9

An excitation potential imaging condition for elastic reverse time migration  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

10

Elastic energy release in great earthquakes and eruptions  

NASA Astrophysics Data System (ADS)

The sizes of earthquakes are measured using well-defined, measurable quantities such as seismic moment and released (transformed) elastic energy. No similar measures exist for the sizes of volcanic eruptions, making it difficult to compare the energies released in earthquakes and eruptions. Here I provide a new measure of the elastic energy (the potential mechanical energy) associated with magma chamber rupture and contraction (shrinkage) during an eruption. For earthquakes and eruptions, elastic energy derives from two sources: (1) the strain energy stored in the volcano/fault zone before rupture, and (2) the external applied load (force, pressure, stress, displacement) on the volcano/fault zone. From thermodynamic considerations it follows that the elastic energy released or transformed (dU) during an eruption is directly proportional to the excess pressure (pe) in the magma chamber at the time of rupture multiplied by the volume decrease (-dVc) of the chamber, so that . This formula can be used as a basis for a new eruption magnitude scale, based on elastic energy released, which can be related to the moment-magnitude scale for earthquakes. For very large eruptions (>100 km3), the volume of the feeder-dike is negligible, so that the decrease in chamber volume during an eruption corresponds roughly to the associated volume of erupted materials , so that the elastic energy is . Using a typical excess pressures of 5 MPa, it is shown that the largest known eruptions on Earth, such as the explosive La Garita Caldera eruption (27-28 million years ago) and largest single (effusive) Colombia River basalt lava flows (15-16 million years ago), both of which have estimated volumes of about 5000 km3, released elastic energy of the order of 10EJ. For comparison, the seismic moment of the largest earthquake ever recorded, the M9.5 1960 Chile earthquake, is estimated at 100 ZJ and the associated elastic energy release at 10EJ.

Gudmundsson, Agust

2014-05-01

11

Elastic energy of protein-DNA chimeras  

NASA Astrophysics Data System (ADS)

We present experimental measurements of the equilibrium elastic energy of protein-DNA chimeras, for two different sets of attachment points of the DNA “molecular spring” on the surface of the protein. Combining these with measurements of the enzyme’s activity under stress and a mechanical model of the system, we determine how the elastic energy is partitioned between the DNA and the protein. The analysis shows that the protein is mechanically stiffer than the DNA spring.

Tseng, Chiao-Yu; Wang, Andrew; Zocchi, Giovanni; Rolih, Biljana; Levine, Alex J.

2009-12-01

12

{sup 144}Sm-{alpha} optical potential at astrophysically relevant energies derived from {sup 144}Sm({alpha},{alpha}){sup 144}Sm elastic scattering  

SciTech Connect

For the determination of the {sup 144}Sm-{alpha} optical potential we measured the angular distribution of {sup 144}Sm({alpha},{alpha}){sup 144}Sm scattering at the energy E{sub lab}=20 MeV with high accuracy. Using the known systematics of {alpha}-nucleus optical potentials we are able to derive the {sup 144}Sm-{alpha} optical potential at the astrophysically relevant energy E{sub c.m.}=9.5 MeV with very limited uncertainties. {copyright} {ital 1997} {ital The American Physical Society}

Mohr, P.; Rauscher, T.; Oberhummer, H. [Institut fuer Kernphysik, Technische Universitaet Wien, Wiedner Hauptstrae 8-10, A-1040 Wien (Austria)] [Institut fuer Kernphysik, Technische Universitaet Wien, Wiedner Hauptstrae 8-10, A-1040 Wien (Austria); Mate, Z.; Fueloep, Z.; Somorjai, E. [Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen (Hungary)] [Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen (Hungary); Jaeger, M.; Staudt, G. [Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen (Germany)] [Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen (Germany)

1997-03-01

13

Low energy elastic electron scattering from CF3Br molecules.  

PubMed

CF3Br is a potentially valuable precursor molecule for generating beams of gas phase Br radicals suitable for electron collisions studies. However, the utility of CF3Br for this purpose depends critically on the availability of sound scattering cross sections to allow the contribution of the precursor to be isolated within the total scattering signal. To this end, here we present elastic differential cross section (DCS) measurements for CF3Br at incident energies between 15 and 50?eV. Comparison of these DCSs to those from the only other available experimental study [Sunohara et al., J. Phys. B: At., Mol. Opt. Phys. 36, 1843 (2003)] and a Schwinger multichannel with pseudo potentials (SMCPPs) calculation [Bettega et al., J. Phys. B: At., Mol. Opt. Phys. 36, 1263 (2003)] shows generally a very good accord. Integral elastic and momentum transfer cross sections, derived from our DCSs, are also found to be in quite good agreement with the SMCPP results. PMID:25833582

Hargreaves, L R; Brunton, J R; Maddern, T M; Brunger, M J

2015-03-28

14

Low energy elastic electron scattering from CF3Br molecules  

NASA Astrophysics Data System (ADS)

CF3Br is a potentially valuable precursor molecule for generating beams of gas phase Br radicals suitable for electron collisions studies. However, the utility of CF3Br for this purpose depends critically on the availability of sound scattering cross sections to allow the contribution of the precursor to be isolated within the total scattering signal. To this end, here we present elastic differential cross section (DCS) measurements for CF3Br at incident energies between 15 and 50 eV. Comparison of these DCSs to those from the only other available experimental study [Sunohara et al., J. Phys. B: At., Mol. Opt. Phys. 36, 1843 (2003)] and a Schwinger multichannel with pseudo potentials (SMCPPs) calculation [Bettega et al., J. Phys. B: At., Mol. Opt. Phys. 36, 1263 (2003)] shows generally a very good accord. Integral elastic and momentum transfer cross sections, derived from our DCSs, are also found to be in quite good agreement with the SMCPP results.

Hargreaves, L. R.; Brunton, J. R.; Maddern, T. M.; Brunger, M. J.

2015-03-01

15

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

E-print Network

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

Doster, Wolfgang

16

Microscopic optical potential analyses of carbon-carbon elastic scattering  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

17

Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities  

NASA Astrophysics Data System (ADS)

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.

Baylin-Stern, Adam C.

18

Virtual coupling potential for elastic scattering of 10,11Be on proton and carbon targets  

NASA Astrophysics Data System (ADS)

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.

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

19

Elastic energy flux by flexible polymers in fluid turbulence.  

PubMed

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

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

2013-07-12

20

Elastic Energy Flux by Flexible Polymers in Fluid Turbulence  

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

21

Neuromechanics of elastic energy storage and recovery during ballistic  

E-print Network

Neuromechanics of elastic energy storage and recovery during ballistic movements. Abstract Muscle physiologists typically study the behavior of muscle under a limited set of conditions, such as isometric, the load-clamp, for quantifying contractile and elastic properties of muscles and their connective tissues

Valero-Cuevas, Francisco

22

Calculations of {sup 8}He+p elastic cross sections using a microscopic optical potential  

SciTech Connect

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)

Lukyanov, V. K.; Zemlyanaya, E. V.; Lukyanov, K. V. [Joint Institute for Nuclear Research, Dubna RU-141980 (Russian Federation); Kadrev, D. N.; Antonov, A. N.; Gaidarov, M. K. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Massen, S. E. [Department of Theoretical Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

2009-08-15

23

Elasticity cells. An investigation of the relation between the energy liberated by a strained metal going into solution and the potential difference resulting.  

E-print Network

placed in a glass vessel containing an unsaturated solution of copper sulphate. The longer rod passed through a rubber stopper in the bottom of the vessel and was firmly fastened with a clamp. To the Tipper end of this rod was fastened a wheel... potentials when Immersed in the copper eulphatc. To neutralise thla "stray" electro-motive force, a counter electro-motive foroe wos placed in the circuit by the potentiometer method* The terminals of the oell and galvanometer circuit were soldered...

Power, Archie Dayton

1912-06-01

24

A Microscopic Optical Potential Approach to {sup 6,8}He+p Elastic Scattering  

SciTech Connect

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.

Lukyanov, V. K.; Zemlyanaya, E. V.; Lukyanov, K. V. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Kadrev, D. N.; Antonov, A. N.; Gaidarov, M. K. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Massen, S. E. [Department of Theoretical Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

2009-08-26

25

Elastic energy of proteins and the stages of protein folding  

E-print Network

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

Lei, Jinzhi

2010-01-01

26

Potential description of elastic scattering of 28Si+16O between 45 and 63 MeV  

Microsoft Academic Search

Excellent fits to extensive elastic scattering data for 28Si+16O measured between 45 and 63 MeV were obtained with energy-dependent, surface-transparent optical potentials without explicitly resorting to a Regge-pole type analysis; S-matrix elements derived from the two analysis are completely different.

V. Shkolnik; D. Dehnhard; S. Kubono; M. A. Franey; S. Tripp

1978-01-01

27

Higher partial-wave potentials from supersymmetry-inspired factorization and nucleon-nucleus elastic scattering  

NASA Astrophysics Data System (ADS)

A simple potential model of the Hulthen type without spin-orbit coupling is considered as the ground-state interaction, and in conjunction with supersymmetric quantum mechanics, higher partial-wave interactions are developed to study the scattering of nucleons from light nuclei. The phase function method is adopted to deal with scattering phase shifts. Applying certain energy-dependent correction factors to our interactions, a close agreement with experimental data is obtained for the elastic scattering of nucleons from alpha particles up to 12 MeV.

Laha, U.; Bhoi, J.

2015-03-01

28

Global Biomass Energy Potential  

Microsoft Academic Search

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

Rua Francisco Dias Velho

2006-01-01

29

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

E-print Network

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.

Susumu Kinpara

2015-03-25

30

Quasi-elastic nuclear scattering at high energies  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

31

On the Kaon-Nucleus Optical Potential at Low Energy  

Microsoft Academic Search

An optical potential approach at low energy is attempted for the kaon-nucleus interaction. The optical potential is introduced by folding the finite range kaon-nucleon potential with the nuclear ground state wave function. The bar{K}-N potential considered is constructed to reproduce the free bar{K}-N scattering lenghts. Using the optical potential we evaluate elastic cross sections of low energy kaon scattering by

Masaru Atarashi; Kiyoto Hira; Hajime Narumi

1978-01-01

32

Calculations of the K$^{+}$-Nucleus Microscopic Optical Potential and of the Corresponding Differential Elastic Cross Sections  

E-print Network

Calculations are made of the $K^{+}+^{12}$C, $^{40}$Ca differential elastic scattering cross sections at the beam momenta 0.635, 0.715, and 0.8 GeV/c. To this end the microscopic optical potential derived in the high-energy approximation was used where existing data on the kaon-nucleon amplitude and on the point-like density distributions of target-nuclei were utilized. The effect of different methods of relativization was studied and shown to play an important role. A good agreement with the experimental data on differential elastic cross sections was obtained.

V. K. Lukyanov; E. V. Zemlyanaya; K. V. Lukyanov; K. M. Hanna

2009-01-16

33

Partitioning of the elastic energy in protein-DNA chimeras  

NASA Astrophysics Data System (ADS)

We synthesize Protein-DNA chimeras where a DNA molecular spring mechanically perturbs the conformation of the protein. We measured the elastic energy stored in one such molecule, consisting of the enzyme Guanylate Kinase coupled to a 60 bp DNA spring. From these measurements, the response of the protein in terms of its enzymatic activity, and a mechanical model of the DNA spring we deduce that, in this case, most of the elastic energy of the molecule is stored in the DNA spring. Thus the DNA spring is ``softer'' than the protein.

Wang, Andrew; Tseng, Chiao-Yu; Rolih, Biljana; Levine, Alex; Zocchi, Giovanni

2010-03-01

34

A Forecast of Energy Demand in Japan Considering Asymmetric Price Elasticities  

Microsoft Academic Search

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

Yutaka Nagata

2001-01-01

35

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

NASA Astrophysics Data System (ADS)

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.

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

2015-02-01

36

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

SciTech Connect

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

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

2005-06-01

37

Elastic positron-cadmium scattering at low energies  

SciTech Connect

The elastic and annihilation cross sections for positron-cadmium scattering are reported up to the positronium-formation threshold (at 2.2 eV). The low-energy phase shifts for the elastic scattering of positrons from cadmium were derived from the bound and pseudostate energies of a very large basis configuration-interaction calculation of the e{sup +}-Cd system. The s-wave binding energy is estimated to be 126{+-}42 meV, with a scattering length of A{sub scat}=(14.2{+-}2.1)a{sub 0}, while the threshold annihilation parameter, Z{sub eff}, was 93.9{+-}26.5. The p-wave phase shift exhibits a weak shape resonance that results in a peak Z{sub eff} of 91{+-}17 at a collision energy of about 490{+-}50 meV.

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

2010-05-15

38

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

SciTech Connect

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

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

2006-07-12

39

Elastic diffractive scattering of nucleons at ultra-high energies  

E-print Network

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.

A. A. Godizov

2014-04-28

40

Elastic scattering analysis of ? and 3He particles on 12C and 16O using a complex folded potential  

NASA Astrophysics Data System (ADS)

The angular distribution of differential cross sections for ? and 3He projectiles elastically scattered from 12C and 16O are calculated at the energy range from 25 to 217 MeV. The double folding model with an energy-target density dependent Jeukenne, Lejeune, and Mahaux effective nucleon-nucleon interaction is used to obtain both real and imaginary parts of the central optical potential. The dependence of the potential on densities of projectile and target nuclei in a factorized form is considered. Good fits to the experimental data are obtained. Nuclear rainbow scattering is also observed and discussed.

Khallaf, S. A. E.; Amry, A. M. A.; Mokhtar, S. R.

1997-10-01

41

Absolute elastic differential electron scattering cross sections in the intermediate energy region. IV - CO  

NASA Technical Reports Server (NTRS)

Using a crossed electron beam-molecular beam scattering geometry and a relative-flow technique, ratios of elastic differential cross sections of CO to those of He have been measured at electron impact energies of 3, 5, 7.5, 9.9, 15, 20, 30, 50, 75, and 100 eV. At each energy, an angular range of 15 to 130 deg has been covered. These ratios have been multiplied by previously known He elastic differential cross sections to obtain elastic differential cross sections for CO. Since pure rotational excitations were not resolved, the elastic differential cross sections are a sum of elastic and pure rotational excitations at room temperature. From a knowledge of differential cross sections (DCS), integral and momentum transfer cross sections have been calculated. Both the DCS and integral cross sections are compared at 50, 75, and 100 eV to a recent two-potential theory of e-molecule scattering. Present results show that the isoelectronic molecules CO and N2 have very similar magnitudes and shapes of their differential cross sections.

Tanaka, H.; Srivastava, S. K.; Chutjian, A.

1978-01-01

42

Surface energy, elasticity and the homogenization of rough surfaces  

NASA Astrophysics Data System (ADS)

The concept of surface energy is widely used to understand numerous aspects of material behavior: fracture, self-assembly, catalysis, void formation, microstructure evolution, and size-effect exhibited by nanostructures. Extensive work exists on deriving homogenized constitutive responses for macroscopic composites—relating effective properties to various microstructural details. In the present work, we focus on homogenization of surfaces. Indeed, elucidation of the effect of surface roughness on the surface energy, stress, and elastic behavior is relatively under-studied and quite relevant to the behavior of both nanostructures and bulk material where surfaces are involved in some form or fashion. We present derivations that relate both periodic and random roughness to the effective surface elastic behavior. We find that the residual surface stress is hardly affected by roughness while the superficial elastic properties are dramatically altered and, importantly, they may also change sign—this has significant ramifications in the interpretation of sensing based on frequency measurement changes. Interestingly, even if the bare surface has a zero surface elasticity modulus, roughness is seen to endow it with one. Using atomistic calculations, we verify the qualitative validity of the obtained theoretical insights. We show, through an illustrative example, that the square of resonance frequency of a cantilever beam with rough surface can decrease almost by a factor of two compared to a flat surface.

Mohammadi, P.; Liu, L. P.; Sharma, P.; Kukta, R. V.

2013-02-01

43

LETTER doi:10.1038/nature12267 Elastic energy storage in the shoulder and the  

E-print Network

#12;LETTER doi:10.1038/nature12267 Elastic energy storage in the shoulder and the evolution of high elastic energy storage and release at the shoulder. These features first appear together approximately 2. Elastic energy storage has been shown to be an important source of poweramplification formanyhigh

Udgaonkar, Jayant B.

44

The elastic modulus of single-wall carbon nanotubes: a continuum analysis incorporating interatomic potentials  

Microsoft Academic Search

A nanoscale continuum theory is established to directly incorporate interatomic potentials into a continuum analysis without any parameter fitting. The theory links interatomic potentials and atomic structure of a material to a constitutive model on the continuum level. The theory is applied to study the linear elastic modulus of a single-wall carbon nanotube. The Young's modulus predicted by this nanoscale

P. Zhang; Y. Huang; P. H. Geubelle; P. A. Klein; K. C. Hwang

2002-01-01

45

Elastic Boundary Conditions in the Theory with Second Gradients in the Thermodynamic Potential  

E-print Network

When describing elastic deformations of a body sometimes it is worth to take in account elastic spatial dispersion. If spatial dispersion is weak, as usually happens, then it can be reduced to dependence of thermodynamic potential on strain gradients. Such a dependence may be worth in association with small body size which imply large gradients. Besides, the inclusion of this dispersion leads to physical phenomena absent without it. An example of the latter is flexoelectricity. Remarkable fact is that while the derivation of differential equations of elastic equilibrium can be made by ordinary means in this case, the derivation of boundary conditions for them is less trivial task. This is due to the fact that strain gradients should be represented in terms of second gradients of independently varied elastic displacements. Detailed consideration of this problem is the subject of this paper.

A. S. Yurkov

2015-01-05

46

Low-Energy Elastic Electron Scattering by Atomic Oxygen  

NASA Technical Reports Server (NTRS)

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.

Zatsarinny O.; Bartschat, K.; Tayal, S. S.

2006-01-01

47

Elastic scattering and total reaction cross section for the Be7 + Al27 system at near-barrier energies  

NASA Astrophysics Data System (ADS)

Elastic scattering angular distributions of the radioactive weakly bound Be7 on Al27 have been measured at energies near the Coulomb barrier. The interaction optical potential is investigated by using different potentials. Total reaction cross sections have also been obtained.

Morcelle, V.; Lichtenthäler, R.; Linares, R.; Morais, M. C.; Guimarães, V.; Lépine-Szily, A.; Gomes, P. R. S.; Lubian, J.; Mendes Junior, D. R.; De Faria, P. N.; Barioni, A.; Gasques, L. R.; Shorto, J. M. B.; Pires, K. C. C.; Zamora, J. C.; Condori, R. P.; Scarduelli, V.; Kolata, J. J.; Amro, H.; Becchetti, F. D.; Jiang, H.; Aguilera, E. F.; Lizcano, D.; Martinez-Quiroz, E.; Garcia, H.

2014-04-01

48

A climbing image nudged elastic band method for finding saddle points and minimum energy paths  

E-print Network

A climbing image nudged elastic band method for finding saddle points and minimum energy paths for finding minimum energy paths is presented. One of the images is made to climb up along the elastic band 2000; accepted for publication 10 October 2000 A modification of the nudged elastic band method

Henkelman, Graeme

49

Semiphenomenological method of analysis for intermediate-energy alpha-nucleus elastic scattering data  

SciTech Connect

We propose a semiphenomenological method of analysis for intermediate energy ..cap alpha..-nucleus elastic scattering experiments and demonstrate its usefulness by analyzing available elastic ..cap alpha..-nucleus scattering data at 1.37 GeV.

Ahmad, I.; Alvi, M.A.

1983-12-01

50

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

E-print Network

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

51

Quantification of the Potential Energy  

E-print Network

(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

Columbia University

52

Elastic Free Energy Drives the Shape of Prevascular Solid Tumors  

PubMed Central

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

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

2014-01-01

53

Biomass Energy Crops: Massachusetts' Potential  

E-print Network

Biomass Energy Crops: Massachusetts' Potential Prepared for: Massachusetts Division of Energy Resources and Massachusetts Department of Conservation & Recreation Prepared by: University of Massachusetts;#12;Executive Summary In Massachusetts, biomass energy has typically meant wood chips derived from the region

Schweik, Charles M.

54

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

SciTech Connect

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

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

2011-10-28

55

Elastic scattering of low-energy electrons by BF3  

NASA Astrophysics Data System (ADS)

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

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

2014-02-01

56

A proof of the cancellation of the redistribution tidal potential effects on the rotation of an elastic Earth model  

NASA Astrophysics Data System (ADS)

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

Baenas, Tomás; Escapa, Alberto; Ferrándiz, Jose Manuel

2014-05-01

57

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

PubMed Central

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

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

2005-01-01

58

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

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

59

Energy flux into the tip of an extending crack in an elastic solid  

Microsoft Academic Search

An expression for the energy flux into the tip of an extending crack in terms of the dynamic elastic field of the crack is derived on the basis of an overall energy rate balance. It is shown that the energy flux depends only on the near-tip elastic field. The expression is compared to other expressions for this dependence which have

L. B. Freund

1972-01-01

60

Elasticity of Energy Demand and Challenges for China's Energy Industry  

Microsoft Academic Search

The rapid growth of energy demand, the lagging growth of energy production and rising pollution problems have raised concerns in several policy areas, including the availability and cost of energy supply and the possibility of further adverse impacts on the environment. This paper begins with an overview of recent developments in energy demand and supply in China. Using a traditional

Jason Zunsheng Yin; David Forrest Gates

2006-01-01

61

Coupled channels calculations for 28Si + 16O and the energy dependence of the optical potential  

Microsoft Academic Search

The systematic energy dependence of recently published surface-transparent potentials is shown to be affected very little by the coupling to the first excited 2+ state in 28Si, although the elastic scattering cross sections depend quite strongly on the coupling. NUCLEAR REACTIONS 28Si+16O, elastic and inelastic sigma(theta), coupled channels analysis.

A. Dudek-Ellis; V. Shkolnik; D. Dehnhard

1978-01-01

62

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

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

63

Total elastic cross section for H-bar-H scattering at thermal energies  

SciTech Connect

This paper reports the elastic scattering cross sections for a few low-lying partial waves and also the converged elastic cross sections with added partial waves in the energy range 10{sup -10}-10{sup -2} a.u. for the H-bar-H system using atomic orbital techniques. The present s-wave predictions are in good agreement with the other existing theoretical estimates. Nonzero low-order partial-wave elastic cross sections show dips like for s-wave scattering. The converged elastic cross section shows structurelike behavior in the energy range 4.2x10{sup -4}-10{sup -2} a.u.

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)

2004-01-01

64

Biomass energy potential in Thailand  

Microsoft Academic Search

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

Shin-ya Yokoyama; Tomoko Ogi; Anan Nalampoon

2000-01-01

65

Human elasticity  

NASA Astrophysics Data System (ADS)

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

McNeill Alexander, R.

1994-11-01

66

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

PubMed Central

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

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

2009-01-01

67

Contribution to the theory of tidal oscillations of an elastic earth. External tidal potential  

NASA Technical Reports Server (NTRS)

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.

Musen, P.

1974-01-01

68

Energy and the Pogo Stick  

NSDL National Science Digital Library

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

VU Bioengineering RET Program,

69

Discrimination of $?$-nucleus potentials in the angular distribution of elastic scattering of $?^-$ hyperons from nuclei  

E-print Network

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

Toru Harada; Yoshiharu Hirabayashi

2012-11-05

70

Empirical assessment of energy-price policies: the case for cross-price elasticities  

Microsoft Academic Search

Evaluations of energy-price policies are necessarily based on measures of the substitution of energy and non-energy inputs. Facing a variety of substitution elasticities, the central question arises which measure would be appropriate. Apparently, for a long time, this question has not been at issue: Allen's elasticities of substitution (AES) have been the most-used measures in applied production analysis. This paper's

Manuel Frondel

2004-01-01

71

Assessment of Triton Potential Energy  

E-print Network

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.

J. L. Friar; G. L. Payne

1996-01-26

72

The elastic energy and character of quakes in solid stars and planets  

NASA Technical Reports Server (NTRS)

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.

Pines, D.; Shaham, J.

1972-01-01

73

Detailed study and mean field interpretation of {sup 16}O+{sup 12}C elastic scattering at seven medium energies  

SciTech Connect

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.

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

74

Parton-parton elastic scattering and rapidity gaps at SSC and LHC energies  

SciTech Connect

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.

Duca, V.D.

1993-08-01

75

Parton-parton elastic scattering and rapidity gaps at Tevatron energies  

SciTech Connect

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.

Del Duca, V.; Tang, Wai-Keung

1993-08-01

76

Parton-Parton Elastic Scattering and Rapidity Gaps at Tevatron Energies  

E-print Network

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.

Vittorio Del Duca; Wai-Keung Tang

1993-08-02

77

Parton-Parton Elastic Scattering and Rapidity Gaps at Very High Energies  

E-print Network

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 very high energies.

Vittorio Del Duca; Wai-Keung Tang

1993-04-23

78

Parton-Parton Elastic Scattering and Rapidity Gaps at SSC and LHC Energies  

E-print Network

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.

Vittorio Del Duca

1993-08-02

79

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

E-print Network

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

William A. Horowitz

2007-02-27

80

Characterization of Elastic Properties in Basalts of the Western Snake River Plain, Idaho: a Mechanostratigraphic Analysis of a Potential Geothermal Reservoir  

NASA Astrophysics Data System (ADS)

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°.

Kessler, J. A.; Evans, J. P.; Schmitt, D. R.; Shervais, J. W.

2013-12-01

81

Energy elastic effects and the concept of temperature in flowing polymeric liquids  

Microsoft Academic Search

The incorporation of energy elastic effects in the modeling of flowing polymeric liquids is discussed. Since conformational\\u000a energetic effects are determined by structural features much smaller than the end-to-end vector of the polymer chains, commonly\\u000a employed single conformation tensor models are insufficient to describe energy elastic effects. The need for a local structural\\u000a variable is substantiated by studying a microscopic

Markus Hütter; Clarisse Luap; Hans Christian Öttinger

2009-01-01

82

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

E-print Network

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

Stanford University

83

Tsunami earthquake generation by the release of gravitational potential energy  

NASA Astrophysics Data System (ADS)

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

McKenzie, Dan; Jackson, James

2012-09-01

84

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

85

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

SciTech Connect

We obtain the nucleation rate of critical droplets for an elastic string moving in a {phi}{sup 6} local potential and subject to noise and damping forces. The critical droplet is a bound soliton-antisoliton pair that carries a section of the string out of the metastable central minimum into one of the stable side minima. The frequencies of small oscillations about the critical droplet are obtained from a Heun equation. We solve the Fokker-Planck equation for the phase-space probability density by projecting it onto the eigenfunction basis obtained from the Heun equation. We employ Farkas' 'flux-overpopulation' method to obtain boundary conditions for solving the Fokker-Planck equation; these restrict the validity of our solution to the moderate to heavy damping regime. We present results for the rate as a function of temperature, well depth, and damping.

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

2004-12-01

86

Phase-shift analysis of low-energy ?p elastic-scattering data  

NASA Astrophysics Data System (ADS)

Using electromagnetic corrections previously calculated by means of a potential model, we have made a phase-shift analysis of the ?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, based on s- and u-channel diagrams with N and ? in the intermediate states, and ? and ? t-channel exchanges, 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 ?NN coupling constant (in the standard form) is 0.0733±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 ?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.

Matsinos, E.; Woolcock, W. S.; Oades, G. C.; Rasche, G.; Gashi, A.

2006-10-01

87

The potential of renewable energy  

SciTech Connect

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

Not Available

1990-03-01

88

Elastic free-energy of the edge of an open lipid bilayer based on the interactions of its constituent molecules  

E-print Network

Lipid-bilayers are the fundamental constituents of the walls of most living cells and lipid vesicles, giving them shape and compartment. The formation and growing of pores in a lipid bilayer have attracted considerable attention from an energetic point of view in recent years. Such pores permit targeted delivery of drugs and genes to the cell, and regulate the concentration of various molecules within the cell. The formation of such pores is caused by various reasons such as changes in cell environment, mechanical stress or thermal fluctuations. Understanding the energy and elastic behaviour of a lipid-bilayer edge is crucial for controlling the formation and growth of such pores. In the present work, the interactions in the molecular level are used to obtain the free energy of the edge of an open lipid bilayer. The resulted free-energy density includes terms associated with flexural and torsional energies of the edge, in addition to a line-tension contribution. The line tension, elastic moduli, and spontaneous normal and geodesic curvatures of the edge are obtained as functions of molecular distribution, molecular dimensions, cutoff distance, and the interaction strength. These parameters are further analyzed by implementing a soft-core interaction potential in the microphysical model. The dependence of the elastic free-energy of the edge to the size of the pore is reinvestigated through an illustrative example, and the results are found to be in agreement with the previous observations.

Meisam Asgari; Aisa Biria

2015-02-17

89

ENERGY ELASTIC EFFECTS AND THE CONCEPT OF TEMPERATURE IN  

E-print Network

, A x B x A B M x x x positive semidefinite K.C. Chen Noncanonical Poisson brackets for elastic ,L x x x time length Time scale separation needed! #12;POISSON BRACKETS Antisymmetric Leibniz derived from systematic coarse-graining procedure Physica A 387 (2008) 6484­6496 #12;DISSIPATIVE BRACKETS

Entekhabi, Dara

90

Price Elasticities for Energy Use in Buildings of the United States  

EIA Publications

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

2014-01-01

91

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

NASA Astrophysics Data System (ADS)

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.

Demetriou, P.; Axiotis, M.

2007-02-01

92

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

SciTech Connect

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

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

2012-06-15

93

Renewable Energy Potential for Brownfield Redevelopment Strategies  

E-print Network

) Resource Availability Biomass Biomass is a broad category of renewable energy that can be well biomass, producing corn ethanol, and generating biopower. The renewable energy technologyRenewable Energy Potential for Brownfield Redevelopment Strategies Renewable energy resources

94

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

Microsoft Academic Search

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

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

2006-01-01

95

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

SciTech Connect

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

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

2014-07-14

96

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

SciTech Connect

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.

Donegan, Sean; Rolett, Anthony

2013-12-31

97

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

PubMed

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

Konow, Nicolai; Roberts, Thomas J

2015-04-01

98

Certifying the Potential Energy Landscape  

E-print Network

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.

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

2013-02-25

99

Adaptive compliant control of humanoid biped foot with elastic energy storage  

Microsoft Academic Search

How to minimize landing impact is a challenging research topic in humanoid locomotion. In this paper, we propose a biomimic design of humanoid biped foot with elastic energy storage aiming to reduce the impact when the foot of swing leg landing on the ground and conserve the energy that is used to be dissipated as a result of foot collide.

Peijie Zhang; Changjiu Zhou; Liandong Zhang; Yantao Tian; Zhenze Liu

2009-01-01

100

Energy dissipation associated with crack extension in an elastic-plastic material  

NASA Technical Reports Server (NTRS)

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 analysis 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.

Shivakumar, K. N.; Crews, J. H., Jr.

1987-01-01

101

Energy dissipation associated with crack extension in an elastic-plastic material  

NASA Technical Reports Server (NTRS)

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.

Shivakumar, K. N.; Crews, J. H., Jr.

1987-01-01

102

Growing correlations and aging of an elastic line in a random potential  

NASA Astrophysics Data System (ADS)

We study the thermally assisted relaxation of a directed elastic line in a two-dimensional quenched random potential by solving numerically the Edwards-Wilkinson equation and the Monte Carlo dynamics of a solid-on-solid lattice model. We show that the aging dynamics is governed by a growing correlation length displaying two regimes: an initial thermally dominated power-law growth which crosses over, at a static temperature-dependent correlation length LT˜T3 , to a logarithmic growth consistent with an algebraic growth of barriers. We present scaling arguments to deal with the crossover-induced geometrical and dynamical effects. This analysis allows us to explain why the results of most numerical studies so far have been described with effective power laws and also permits us to determine the observed anomalous temperature dependence of the characteristic growth exponents. We argue that a similar mechanism should be at work in other disordered systems. We generalize the Family-Vicsek stationary scaling law to describe the roughness by incorporating the waiting-time dependence or age of the initial configuration. The analysis of the two-time linear response and correlation functions shows that a well-defined effective temperature exists in the power-law regime. Finally, we discuss the relevance of our results for the slow dynamics of vortex glasses in high- Tc superconductors.

Iguain, José Luis; Bustingorry, Sebastian; Kolton, Alejandro B.; Cugliandolo, Leticia F.

2009-09-01

103

Proton-Deuteron Elastic Scattering at Very Low Energy.  

NASA Astrophysics Data System (ADS)

Contemporary nuclear theory is unable to furnish an adequate quantitative description of the three-nucleon system. The non-relativistic, nucleons-only dynamical theory--whether utilizing dispersion-theoretic, meson field -theoretic, or phenomenologically derived nuclear potentials --fails to replicate the trinucleon binding energies without the inclusion of three-body forces characterized by ad hoc parameters. Attempts to replicate three-nucleon continuum observables below the deuteron breakup threshold have been fairly successful in the case of the n-d system, but significant failures have attended these attempts for the p-d scattering system. The most serious such failure is a discrepancy between the theoretical and phenomenological values of the p-d S-wave scattering lengths. Besides suggesting the existence of subtle interactions between the nuclear and electrostatic forces in the three-body system, this discrepancy has challenged a long-held, though as yet incompletely understood, assumption that approximately linear correlations exist between the trinucleon binding energy and various parameters characterizing the three-nucleon system. A consensus has emerged among theorists that these discrepancies are the result of a singularity in the doublet S-wave effective range function near the two-body threshold that hinders the ability to infer the scattering length on the basis of measurements made at excessively high scattering energies. Since the doublet and quartet S-wave eigenphaseshifts are coupled in the cross section, errors in inferring the former are reflected in erroneous determinations of the latter. Relative differential cross sections for the ^2H(p,p)^2H reaction have been measured at a number of (center-of-mass) angles between 36.9^circ and 140.5 ^circ at a proton laboratory energy of 315 keV. These data are part of a larger set that also includes measurements of the relative cross section at 240 keV. The data are compared with theoretical calculations of the cross sections that explore the influence of various partial wave eigenphaseshifts and spin mixing parameters, preparatory to a global phase shift analysis being undertaken by the author and his collaborators.

Black, Timothy Charles

1995-11-01

104

Energy-dependent optical model potentials for ? and deuteron with 12C  

NASA Astrophysics Data System (ADS)

Energy-dependent phenomenological optical model potentials based on a single-folding model approach for the ?-12C and deuteron-12C systems were obtained for incident energies between 10 and 100 MeV/nucleon. The Lane-consistent Bruyères Jeukenne-Lejeune-Mahaux model nucleon-nucleus potentials were used in these calculations. With only three free parameters, these potentials account satisfactorily for both angular distributions of elastic scattering cross sections and total reaction cross sections of both projectile-target systems within the energy range studied. Comparisons were made between the present potentials and other systematic phenomenological potentials.

Pang, D. Y.; Ye, Y. L.; Xu, F. R.

2012-09-01

105

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

E-print Network

.......................................................................................... 11 2.2 Harmonic Potential Function Method .................................................. 13 2.3 Two Types of Contact Problems .......................................................... 15 2.3.1 Problems with BCs of the First Type......................................... 19 2.3.2 Problems with BCs of the Second Type ................................. 24 2.4 Adhesive Contact Problems ................................................................. 28 2.4.1 Solution by Superposition...

Zhou, Songsheng

2012-02-14

106

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

NASA Technical Reports Server (NTRS)

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).

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

1992-01-01

107

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

PubMed

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

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

2015-03-01

108

Potential of geothermal energy in China  

E-print Network

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 ...

Sung, Peter On

2010-01-01

109

Microscopic positive-energy potential based on Gogny interaction  

E-print Network

We present nucleon elastic scattering calculation based on Green's function formalism in the Random-Phase Approximation. For the first time, the Gogny effective interaction is used consistently throughout the whole calculation to account for the complex, non-local 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 section. Double counting of the particle-hole second-order contribution is carefully addressed. The resulting integro-differential Schr\\"odinger equation for the scattering process is solved without localization procedures. The method is applied to neutron and proton elastic scattering from $^{40}$Ca. 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 much too high volume integral of the real potential for large partial waves. Moreover, this works opens the way for future effective interactions suitable simultaneously for both nuclear structure and reaction.

G. Blanchon; M. Dupuis; H. F. Arellano; N. Vinh Mau

2014-10-28

110

Microscopic positive-energy potential based on the Gogny interaction  

NASA Astrophysics Data System (ADS)

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.

Blanchon, G.; Dupuis, M.; Arellano, H. F.; Vinh Mau, N.

2015-01-01

111

cap alpha. /sup 4/He elastic scattering at high energies  

SciTech Connect

Differential cross sections for ..cap alpha.. /sup 4/He elastic scattering have been calculated at incident ..cap alpha..-particle momenta of 4.32, 5.07, and 7.0 GeV/c within the framework of Glauber multiple scattering theory. The full Glauber amplitude has been calculated using the Monte Carlo method for evaluating multidimensional integrals. We found that, in general, the more realistic double-Gaussian model for the density brings theory closer to experiment as compared to the generally used single-Gaussian model in some momentum transfer regions. Our results with the double-Gaussian model and an acceptable set of NN parameters are in fairly good agreement with the experimental data at 4.32 and 5.07 GeV/c.

Usmani, A.A.; Ahmad, I.; Usmani, Q.N.

1989-03-01

112

Theoretical and experimental investigations of elastic scattering spectroscopy as a potential diagnostic for tissue pathologies  

SciTech Connect

The spectral distribution of the diffuse reflectance of five sizes of polystyrene microspheres has been measured with an elastic scatter spectrometer designed for optical biopsy of living tissue. The microsphere sizes are representative of the suspected scattering centers in living tissue. The experiment data are discussed and interpreted in the framework of Mie scattering theory and Monte-Carlo transport analysis. Present results support the assertion that Mie theory is necessary to describe the spectral features of elastic scatter spectroscopy in tissue.

Boyer, J.; Mourant, J.R.; Bigio, I.J.

1994-04-01

113

Energy current imaging method for time reversal in elastic media  

SciTech Connect

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

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

2009-01-01

114

Biomass energy potential in Turkey  

Microsoft Academic Search

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

K. Kaygusuz; M. F. Türker

2002-01-01

115

Geothermal Energy: Tapping the Potential  

ERIC Educational Resources Information Center

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

Johnson, Bill

2008-01-01

116

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

NASA Astrophysics Data System (ADS)

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

Ghosh, Avijit; Ray, Debasis

2015-03-01

117

Energy from Forest Biomass: Potential Economic Impacts  

E-print Network

Energy from Forest Biomass: Potential Economic Impacts in Massachusetts Prepared for: Massachusetts Bioenergy Initiative, a multifaceted study of biomass energy potential in Massachusetts. The economic impact study looks specifically at impacts in the 5 western counties of the Commonwealth, where biomass energy

Schweik, Charles M.

118

On the physical basis for the nematic rubber elastic free energy  

E-print Network

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.

J. S. Biggins; M. Warner

2009-10-20

119

Structure of elastic p-p scattering at low and high energies  

SciTech Connect

It is observed that p-p elastic scattering at 90/sup 0/ between 0.3 and 1.0 GeV is described by planar-transverse amplitude of which two are equal in magnitude and one is about three times larger in magnitude. This feature, extrapolated to much higher energies, is used to predict p-p polarization quantities, in part by itself, in part in combination with the extension of another, previously observed feature of planar-transverse amplitudes. Comparison with existing data is favorable. Predictions are then made for other, yet unmeasured but readily measurable polarization quantities for p-p elastic scattering.

Arash, F.; Moravcsick, M.J.; Goldstein, G.R.

1985-02-01

120

Elastic Nd scattering at intermediate energies as a tool for probing the short-range deuteron structure  

SciTech Connect

A calculation of the deuteron polarization observables A{sub y}{sup d}, A{sub yy}, A{sub xx}, A{sub xz} and the differential cross section for elastic nucleon-deuteron scattering at incident deuteron energies 270 and 880 MeV in lab is presented. A comparison of the calculations with two different deuteron wave functions derived from the Bonn-CD NN-potential model and the dressed-quark-bag model is carried out. A model-independent approach, based on an optical-potential framework, is used in which a nucleon-nucleon T matrix is assumed to be local and taken on the energy shell, but still depends on the internal nucleon momentum in a deuteron.

Shikhalev, M. A., E-mail: shikhalev@jinr.r [Joint Institute for Nuclear Research (Russian Federation)

2009-04-15

121

Potential Energy and the Body Electric  

E-print Network

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 ...

Helmreich, Stefan

122

Wind energy potential in Palestine  

Microsoft Academic Search

Weibull parameters of the wind speed distribution function were computed for 49 weather stations in Palestine. Wind potentials in kWh\\/m2 yr were calculated at the above stations, then contours of wind potential were drawn. Electricity from the wind can be generated, in some locations in the West Bank, at a cost of 0.07 $\\/kWh.

Afif Hasan

1997-01-01

123

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

E-print Network

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

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

124

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

E-print Network

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

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

125

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

SciTech Connect

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

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

2010-01-15

126

Interfacial profiles in fluid/liquid systems: a description based on the storing of elastic energy.  

PubMed

An analytical expression for the interfacial energy is found by solving a Poisson equation and assuming a Boltzmann distribution of volume elements forming the fluid/liquid system. Interfacial phenomena are treated as a result of the response of a liquid when it makes contact with other fluid phase, in order to reach thermal and mechanical equilibrium. This model gives a quantitative description of the interface, obtaining values for its molar, force and energy density profiles. Also, our model allows the determination of the proportion of the fluids present in the interfacial zone, the values of interfacial tension and thickness. In the case of water+n-alkanes systems, the tensions are in agreement with the behavior shown by the experimental data. Finally, the values for interfacial thickness predicted from molar density profiles are lower than the range of influence of the elastic energy and elastic field. PMID:21421216

Castellanos-Suárez, Aly J; Toro-Mendoza, Jhoan; García-Sucre, Máximo

2011-06-01

127

Potential Water and Energy Savings from Showerheads  

SciTech Connect

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

Biermayer, Peter J.

2005-09-28

128

Exploring Potential Energy Surfaces for Enzymatic Reactions  

E-print Network

Exploring Potential Energy Surfaces for Enzymatic Reactions Using QM/MM Calculations Prof. H, and wound healing Related to cancer, inflammation and connective tissue diseases Zinc dependent #12;MMP2. B 2010, 114, 1030 S C O HCCH2 S HH O * #12;Exploring the Potential Energy Surface for KDO8P Synthase

Schlegel, H. Bernhard

129

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

E-print Network

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 ...

Ertan, E.

130

Elastic and inelastic eCF4 cross sections at low energies: fit to the experimental data  

Microsoft Academic Search

The momentum transfer elastic and the total vibrationally inelastic electron-CF4 cross sections at energies 0.02-4 eV are varied until the best fits of the measured electron drift velocity and diffusion\\/mobility ratio are obtained. The elastic cross section exhibits a well pronounced minimum somewhere in the range 0.2-1.3 eV.

B. Stefanov; N. Popkirova; L. Zarkova

1988-01-01

131

On the Chemical Potential of Dark Energy  

E-print Network

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.

S. H. Pereira

2008-06-23

132

Energy Price and Income-Elasticities of Demand: Some Estimates for the UK Using the Cointegration Procedure  

Microsoft Academic Search

The aim of this paper is to reexamine aggregate energy demand in the United Kingdom using the relatively recent procedure of cointegration. It shows energy consumption, the real price of energy, and real GDP cointegrate, which implies the existence of a long-run equilibrium. The associated long-run price-elasticity estimate is about -0.3 and the long-run income-elasticity estimate is about 0.5. The

Lester Hunt; Neil Manning

1989-01-01

133

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

PubMed Central

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

Nakamura, Yoshihiro; Awa, Shoichi

2014-01-01

134

Elastic Scattering of Low-Energy Electrons byTetrahydrofuran  

SciTech Connect

We present the results of ab initio calculations for elasticelectron scattering by tetrahydrofuran (THF) using the complex Kohnvariational method. We carried out fixed-nuclei calculations at theequilibrium geometry of the target molecule for incident electronenergies up to 20 eV. The calculated momentum transfer cross sectionsclearly reveal the presence of broad shape resonance behavior in the 8-10eV energy range, in agreement with recent experiments. The calculateddifferential cross sections at 20 eV, which include the effects of thelong-range electron-dipole interaction, are alsofound to be in agreementwith the most recent experimental findings.

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

2006-05-09

135

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

SciTech Connect

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

Nguyen, Ba Nghiep; Paquette, Joshua

2010-08-01

136

Geothermal Energy Potential in Western United States  

ERIC Educational Resources Information Center

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

Pryde, Philip R.

1977-01-01

137

Renewable energy in India: Status and potential  

Microsoft Academic Search

A majority of the Indian population does not have access to convenient energy services (LPG, electricity). Though India has made significant progress in renewable energy, the share of modern renewables in the energy mix is marginal. This paper reviews the status and potential of different renewables (except biomass) in India. This paper documents the trends in the growth of renewables

Indu R. Pillai; Rangan Banerjee

2009-01-01

138

Remarks on the energy release rate for an antiplane moving crack in couple stress elasticity  

E-print Network

This paper is concerned with the steady-state propagation of an antiplane semi-infinite crack in couple stress elastic materials. A distributed loading applied at the crack faces and moving with the same velocity of the crack tip is considered, and the influence of the loading profile variations and microstructural effects on the dynamic energy release rate is investigated. The behaviour of both energy release rate and maximum total shear stress when the crack tip speed approaches the critical speed (either that of the shear waves or that of the localised surface waves) is studied. The limit case corresponding to vanishing characteristic scale lengths is addressed both numerically and analytically by means of a comparison with classical elasticity results.

L. Morini; A. Piccolroaz; G. Mishuris

2014-04-10

139

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

SciTech Connect

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

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

2011-05-15

140

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

SciTech Connect

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

Petersson, N A; Sjogreen, B

2008-07-15

141

Methods to compute dislocation line tension energy and force in anisotropic elasticity  

NASA Astrophysics Data System (ADS)

A frame indifferent formulation of the energy and force on a dislocation in a line tension model in an anisotropic elasticity media is presented. This formulation is valid for any dislocation line direction and Burgers' vector and expresses the energy and force in terms of an integral for which no general analytical solution can be calculated. Three numerical methods are investigated to evaluate the energy and the force: direct numerical integration, spherical harmonics expansions and an interpolation table method. We analyze the convergence and computational cost of each method and compare them with a view to selecting the most appropriate for implementation in large scale dislocation dynamics codes.

Aubry, S.; Fitzgerald, S. P.; Arsenlis, A.

2014-01-01

142

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

NASA Astrophysics Data System (ADS)

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.

Deur, Alexandre

1999-10-01

143

Energy potential of modern landfills  

SciTech Connect

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

Bogner, J.E.

1990-01-01

144

Elastic Strain Energy Storage and Neighboring Organ Assistance for Fluid Propulsion  

NASA Astrophysics Data System (ADS)

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

Arun, C. P.

2003-11-01

145

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

PubMed

The structural and mechanical properties of graphene-like honeycomb monolayer structures of MoS2 (g-MoS2) under various large strains are investigated using density functional theory (DFT). g-MoS2 is mechanically stable and can sustain extra large strains: the ultimate strains are 0.24, 0.37, and 0.26 for armchair, zigzag, and biaxial deformation, respectively. The in-plane stiffness is as high as 120 N m(-1) (184 GPa equivalently). The third, fourth, and fifth order elastic constants are indispensable for accurate modeling of the mechanical properties under strains larger than 0.04, 0.07, and 0.13 respectively. The second order elastic constants, including in-plane stiffness, are predicted to monotonically increase with pressure while the Poisson ratio monotonically decreases with increasing pressure. With the prominent mechanical properties including large ultimate strains and in-plane stiffness, g-MoS2 is a promising candidate of elastic energy storage for clean energy. It possesses a theoretical energy storage capacity as high as 8.8 MJ L(-1) and 1.7 MJ kg(-1), or 476 W h kg(-1), larger than a Li-ion battery and is environmentally friendly. PMID:24126736

Peng, Qing; De, Suvranu

2013-11-28

146

Elastic scattering of an oxygen atom on a silicon atom in the 10-500 eV range of relative kinetic energies  

NASA Astrophysics Data System (ADS)

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.

Sycheva, A. A.; Balint-Kurti, G. G.; Palov, A. P.

2014-11-01

147

Energy saving potential of various roof technologies  

E-print Network

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

Ray, Stephen D. (Stephen Douglas)

2010-01-01

148

Multivessel Batch Distillation Potential Energy Savings  

E-print Network

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

Skogestad, Sigurd

149

Pole structure from energy-dependent and single-energy fits to GWU-SAID ? N elastic scattering data  

NASA Astrophysics Data System (ADS)

The pole structure of the current George Washington University (GWU-SAID) partial-wave analysis of elastic ? N scattering and ? 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 fits to data.

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

2015-01-01

150

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

PubMed Central

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

Astley, Henry C.; Roberts, Thomas J.

2012-01-01

151

Synergy of elastic and inelastic energy loss on ion track formation in SrTiO?.  

PubMed

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

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

2015-01-01

152

The Intermediate Energy Elastic Scattering of Protons by ?-CLUSTER 20Ne and 24Mg Nuclei  

NASA Astrophysics Data System (ADS)

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.

Berezhnoy, Yu. A.; Mikhailyuk, V. P.; Pilipenko, V. V.

153

Bundle structures of stretching-energy and nonlinear interactions among modes in elastic wave turbulence  

NASA Astrophysics Data System (ADS)

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.

Takaoka, Masanori; Yokoyama, Naoto

2015-01-01

154

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...

155

Economic Energy Savings Potential in Federal Buildings  

SciTech Connect

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

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

2000-09-04

156

Industrial Energy Conservation Potentials in North Carolina  

E-print Network

. Potential energy savings are also found in the operation of lights, motors, heating ventilating and air conditioning (HVAC) systems, ovens, temperature setting schedules, and many others. Table 2 summarizes the most frequently recommended EGOs..., their corresponding energy and cost savings, and implementation costs. Some of the major energy consuming equipment with related EGOs will be discussed. Table 1 Types of Manufacturers Type /I Savings ImpL MMBTU $ Cost Textile 19 99,374 634,881 376,464 Wood...

Barakat, M. G.; Singh, H.; Mallik, A. K.

157

Numerical simulations for width fluctuations in compound elastic and inelastic scattering at low energies  

SciTech Connect

The statistical theories - the Hauser-Feshbach model with the width fluctuation correction - play a central role in studying nuclear reactions in the fast energy region, hence the statistical model codes are essential for the nuclear data evaluations nowadays. In this paper, we revisit issues regarding the statistical model calculations in the fast energy range, such as the inclusion of the direct channels, and the energy averaged cross sections using different statistical assumptions. Although they have been discussed for a long time, we need more precise quantitative investigations to understand uncertainties coming from the models deficiencies in the fast energy range. For example, the partition of compound formation cross section into the elastic and inelastic channels depends on the elastic enhancement factor calculated from the statistical models. In addition, unitarity of S-matrix constrains this partition when the direct reactions are involved. Practically some simple assumptions, which many nuclear reaction model codes adopt, may work reasonably for the nuclear data evaluations. However, the uncertainties on the evaluated cross sections cannot go lower than the model uncertainty itself. We perform numerical simulations by generating the resonances using the R-matrix theory, and compare the energy (ensemble) averaged cross sections with the statistical theories, such as the theories of Moldauer, HRTW (Hofmann, Richert, Tepel, and Weidenmueller), KKM (Kawai-Kerman-McVoy), and GOE (Gaussian orthogonal ensemble).

Kawano, Toshihiko [Los Alamos National Laboratory; Talou, Patrick [Los Alamos National Laboratory

2012-09-18

158

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

159

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

SciTech Connect

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

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

1995-12-31

160

Energy dependence of slope parameter in elastic nucleon-nucleon scattering  

E-print Network

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

Okorokov, V A

2015-01-01

161

Energy dependence of slope parameter in elastic nucleon-nucleon scattering  

E-print Network

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

V. A. Okorokov

2015-01-06

162

Quantum potential energy as concealed motion  

E-print Network

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.

Peter Holland

2014-11-13

163

Quantum Potential Energy as Concealed Motion  

NASA Astrophysics Data System (ADS)

It is known that the Schrödinger 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.

Holland, Peter

2015-02-01

164

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

E-print Network

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

Nadja Kutz

2012-02-13

165

LEAN ENERGY ANALYSIS: IDENTIFYING, DISCOVERING AND TRACKING ENERGY SAVINGS POTENTIAL  

E-print Network

of lean manufacturing. In terms of lean manufacturing, "any activity that does not add valueLEAN ENERGY ANALYSIS: IDENTIFYING, DISCOVERING AND TRACKING ENERGY SAVINGS POTENTIAL KELLY KISSOCK AND RESOURCE SOLUTIONS HAVERHILL, MASSECHUTSETTS ABSTRACT Energy in manufacturing facilities is used for direct

Kissock, Kelly

166

Potential energy function for the hydroperoxyl radical  

SciTech Connect

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

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

1987-03-12

167

Elastic energy storage and release in white muscle from dogfish scyliorhinus canicula  

PubMed

The production of work by the contractile component (CC) and the storage and release of work in the elastic structures that act in series (the series elastic component, SEC) with the contractile component were measured using white muscle fibres from the dogfish Scyliorhinus canicula. Heat production was also measured because the sum of work and heat is equivalent to the energy cost of the contraction (ATP used). These energy fluxes were evaluated in contractions with constant-velocity shortening either during stimulation or during relaxation. The muscle preparation was tetanized for 0.6 s and shortened by 1 mm (approximately 15 % of L0) at 3.5 or 7.0 mm s-1 (approximately 15 or 30 % of V0), where L0 is the muscle length at which isometric force is greatest and V0 is the maximum velocity of shortening. In separate experiments, the stiffness of the SEC was characterized from measurements of force responses to step changes in the length of contracting muscle. Using the values of SEC stiffness, we evaluated separately the work and heat associated with the CC and with the SEC. The major findings were (1) that work stored in the SEC could be completely recovered as external work when shortening occurred during relaxation (none of the stored work being degraded into heat) and (2) that, when shortening occurred progressively later during the contraction, the total energy cost of the contraction declined towards that of an isometric contraction. PMID:9851903

Lou; Curtin; Woledge

1999-01-01

168

Nudged-elastic band method with two climbing images: finding transition states in complex energy landscapes  

E-print Network

The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, C2-NEB finds it with higher stability and accuracy. However, C2-NEB is suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS but guarantees that the climbing images approach it from the opposite sides along the MEP, and it estimates accuracy from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB (SS-NEB).

Zarkevich, Nikolai A

2014-01-01

169

Nudged-elastic band method with two climbing images: finding transition states in complex energy landscapes.  

PubMed

The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with a serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, then C2-NEB finds it too. However, improved stability of C2-NEB makes it suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS, but also guarantees, by construction, that the climbing images approach it from the opposite sides along the MEP. In addition, C2-NEB provides an accuracy estimate from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB. PMID:25591337

Zarkevich, Nikolai A; Johnson, Duane D

2015-01-14

170

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

171

Potential energy sputtering of EUVL materials  

SciTech Connect

Of the many candidates employed for understanding the erosion of critical Extreme Ultraviolet Lithography (EUVL) components, potential energy damage remains relatively uninvestigated. Unlike the familiar kinetic energy sputtering, which is a consequence of the momentum transferred by an ion to atoms in the target, potential energy sputtering occurs when an ion rapidly collects charge from the target as it neutralizes. Since the neutralization energy of a singly charged ion is typically on the order of 10 eV, potential energy effects are generally neglected for low charge state ions, and hence the bulk of the sputtering literature. As an ion's charge state is increased, the potential energy (PE) increases rapidly, e.g. PE(Xe{sup 1+})= 11 eV, PE(Xe{sup 10+}) = 810 eV, PE(Xe{sup 20+}) = 4.6 keV, etc. By comparison, the binding energy of a single atom on a surface is typically about 5 eV, so even relatively inefficient energy transfer mechanisms can lead to large quantities of material being removed, e.g. 25% efficiency for Xe{sup 10+} corresponds to {approx} 40 atoms/ion. By comparison, singly charged xenon ions with {approx} 20 keV of kinetic energy sputter only about 5 atoms/ion at normal incidence, and less than 1 atom/ion at typical EUV source energies. EUV light sources are optimized for producing approximately 10{sup 16} xenon ions per shot with an average charge state of q=10 in the core plasma. At operational rates of {approx}10 kHz, the number of ions produced per second becomes a whopping 10{sup 20}. Even if only one in a billion ions reaches the collector, erosion rates could reach {approx}10{sup 12} atoms per second, severely reducing the collector lifetime (for an average yield of 10 atoms/ion). In addition, efforts to reduce contamination effects may contribute to reduced neutralization and even larger potential energy damages rates (discussed further below). In order to provide accurate estimates for collector lifetimes and to develop mitigation schemes, NIST is working to understand and quantify potential energy damage mechanisms on materials relevant to EUVL. Accurate potential energy damage rates can then be used for projecting component lifetimes as source plasma conditions are modified and characterized. This chapter will serve to provide an introduction and some background to the physics of highly charged ions and some of the relevant experimental work in the literature. This chapter will first provide a brief background and an overview of the interaction of highly charged ions (HCIs) with solids as it is currently understood. Secondly, it will present current data from screen test measurements performed to isolate and evaluate the effects of potential energy damage on critical EUVL materials. We will then speculate on the implications of work to date and the outlook for EUVL development and, finally, summarize.

Pomeroy, J M; Ratliff, L P; Gillaspy, J D; Bajt, S

2004-07-02

172

POTENTIAL ENERGY SAVINGS OF MULTIVESSEL BATCH DISTILLATION  

E-print Network

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

Skogestad, Sigurd

173

Potential reduction of DSN uplink energy cost  

NASA Technical Reports Server (NTRS)

DSN Earth stations typically transmit more power than that required to meet minimum specifications for uplink performance. Energy and cost savings that could result from matching the uplink power to the amount required for specified performance are studied. The Galileo mission was selected as a case study. Although substantial reduction in transmitted energy is possible, potential savings in source energy (oil or electricity) savings are much less. This is because of the rising inefficiency in power conversion and radio frequency power generation that accompanies reduced power output.

Dolinsky, S.; Degroot, N. F.

1982-01-01

174

CONDENSED MATTER: STRUCTURE, THERMAL AND MECHANICAL PROPERTIES: Pseudo-potential investigations of structural, elastic and thermal properties of tungsten disilicide  

NASA Astrophysics Data System (ADS)

The plane-wave pseudopotential method using the generalized gradient approximation within the density functional theory is used to investigate the structure and bulk modulus of WSi2. The quasi-harmonic Debye model, using a set of total energy versus cell volume obtained with the plane-wave pseudopotential method, is applied to the study of the elastic properties and vibrational effects. We have analysed the bulk modulus of WSi2 up to 1600 K. The major trend shows that the WSi2 crystal becomes more compressible when the temperature rises and the increase of compressibility leads to the decrease of Debye temperature. The predicted temperature and pressure effects on the thermal expansion, heat capacity and Debye temperatures are determined from the non-equilibrium Gibbs functions and compared with the data available.

Xu, Guo-Liang; Chen, Jing-Dong; Xia, Yao-Zheng; Liu, Xue-Feng

2009-08-01

175

Low frequency energy scavenging using sub-wave length scale acousto-elastic metamaterial  

NASA Astrophysics Data System (ADS)

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.

Ahmed, Riaz U.; Banerjee, Sourav

2014-11-01

176

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

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

177

The meshless hypersingular boundary node method for three-dimensional potential theory and linear elasticity problems  

E-print Network

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

Paulino, Glaucio H.

178

Low-energy elastic electron scattering from isobutanol and related alkyl amines  

NASA Astrophysics Data System (ADS)

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.

Fedus, Kamil; Navarro, C.; Hargreaves, L. R.; Khakoo, M. A.; Silva, F. M.; Bettega, M. H. F.; Winstead, C.; McKoy, V.

2014-09-01

179

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

PubMed Central

In endocytosis, scaffolding is one of the mechanisms to create membrane curvature by moulding the membrane into the spherical shape of the clathrin cage. However, the impact of membrane elastic parameters on the assembly and shape of clathrin lattices has never been experimentally evaluated. Here, we show that membrane tension opposes clathrin polymerization. We reconstitute clathrin budding in vitro with giant unilamellar vesicles (GUVs), purified adaptors and clathrin. By changing the osmotic conditions, we find that clathrin coats cause extensive budding of GUVs under low membrane tension while polymerizing into shallow pits under moderate tension. High tension fully inhibits polymerization. Theoretically, we predict the tension values for which transitions between different clathrin coat shapes occur. We measure the changes in membrane tension during clathrin polymerization, and use our theoretical framework to estimate the polymerization energy from these data. Our results show that membrane tension controls clathrin-mediated budding by varying the membrane budding energy. PMID:25695735

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

2015-01-01

180

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

SciTech Connect

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.

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

181

Potential energy savings from aquifer thermal energy storage  

SciTech Connect

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

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

1988-07-01

182

Sparse representation for a potential energy surface  

NASA Astrophysics Data System (ADS)

We propose a simple scheme to estimate the potential energy surface (PES) for which the accuracy can be easily controlled and improved. It is based on model selection within the framework of linear regression using the least absolute shrinkage and selection operator (LASSO) technique. Basis functions are selected from a systematic large set of candidate functions. The sparsity of the PES significantly reduces the computational cost of evaluating the energy and force in molecular dynamics simulations without losing accuracy. The usefulness of the scheme for describing the elemental metals Na and Mg is clearly demonstrated.

Seko, Atsuto; Takahashi, Akira; Tanaka, Isao

2014-07-01

183

Computed potential energy surfaces for chemical reactions  

NASA Technical Reports Server (NTRS)

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).

Walch, Stephen P.

1994-01-01

184

Computed potential energy surfaces for chemical reactions  

NASA Technical Reports Server (NTRS)

The objective was to obtain accurate potential energy surfaces (PES's) for a number of reactions which are important in the H/N/O combustion process. The interest in this is centered around the design of the SCRAM jet engine for the National Aerospace Plane (NASP), which was envisioned as an air-breathing hydrogen-burning vehicle capable of reaching velocities as large as Mach 25. Preliminary studies indicated that the supersonic flow in the combustor region of the scram jet engine required accurate reaction rate data for reactions in the H/N/O system, some of which was not readily available from experiment. The most important class of combustion reactions from the standpoint of the NASP project are radical recombinaton reactions, since these reactions result in most of the heat release in the combustion process. Theoretical characterizations of the potential energy surfaces for these reactions are presented and discussed.

Walch, Stephen P.

1990-01-01

185

Band-gap deformation potential and elasticity limit of semiconductor free-standing nanorods characterized in situ by scanning electron microscope-cathodoluminescence nanospectroscopy.  

PubMed

Modern field-effect transistors or laser diodes take advantages of band-edge structures engineered by large uniaxial strain ?zz, available up to an elasticity limit at a rate of band-gap deformation potential azz (= dEg/d?zz). However, contrary to aP values under hydrostatic pressure, there is no quantitative consensus on azz values under uniaxial tensile, compressive, and bending stress. This makes band-edge engineering inefficient. Here we propose SEM-cathodoluminescence nanospectroscopy under in situ nanomanipulation (Nanoprobe-CL). An apex of a c-axis-oriented free-standing ZnO nanorod (NR) is deflected by point-loading of bending stress, where local uniaxial strain (?cc = r/R) and its gradient across a NR (d?cc/dr = R(-1)) are controlled by a NR local curvature (R(-1)). The NR elasticity limit is evaluated sequentially (?cc = 0.04) from SEM observation of a NR bending deformation cycle. An electron beam is focused on several spots crossing a bent NR, and at each spot the local Eg is evaluated from near-band-edge CL emission energy. Uniaxial acc (= dEg/d?cc) is evaluated at regulated surface depth, and the impact of R(-1) on observed acc is investigated. The acc converges with -1.7 eV to the R(-1) = 0 limit, whereas it quenches with increasing R(-1), which is attributed to free-exciton drift under transversal band-gap gradient. Surface-sensitive CL measurements suggest that a discrepancy from bulk acc = -4 eV may originate from strain relaxation at the side surface under uniaxial stress. The nanoprobe-CL technique reveals an Eg(?ij) response to specific strain tensor ?ij (i, j = x, y, z) and strain-gradient effects on a minority carrier population, enabling simulations and strain-dependent measurements of nanodevices with various structures. PMID:25689728

Watanabe, Kentaro; Nagata, Takahiro; Wakayama, Yutaka; Sekiguchi, Takashi; Erdélyi, Róbert; Volk, János

2015-03-24

186

Computation of electron-impact rotationally elastic total cross sections for methanol over an extensive range of impact energy (0.1 - 2000 eV)  

NASA Astrophysics Data System (ADS)

Theoretical rotationally elastic total cross sections for electron scattering from methanol over the incident energy range 0.1-2000 eV are presented. The computation of such cross sections for methanol is reported over such an extended energy range. We have employed two distinct formalisms to compute the cross sections across this energy range; between 0.1 eV and the ionization threshold of the target we have used the ab initio R-matrix method, while at higher energies the spherical complex optical potential method is invoked. The results from both formalisms match quite well at energies where they overlap and hence imply that they are consistent with each other. These total cross-section results are also in very good agreement with available experimental data and earlier theoretical data. The composite methodology employed here is well established and can be used to predict cross sections for other targets where data is scarce or not available.

Vinodkumar, Minaxi; Limbachiya, Chetan; Barot, Avani; Mason, Nigel

2013-01-01

187

Modeling cusps in adiabatic potential energy surfaces.  

PubMed

A method for modeling cusps on adiabatic potential energy surfaces without the need for any adiabatic-to-diabatic transformation is presented and shown to be successfully applied to the (2)A? state of NO2. The more complicated case of a system with permutationally equivalent crossing seams is also examined and illustrated by considering the two first (2)A' states of the nitrogen trimer. PMID:25633429

Galvão, B R L; Mota, V C; Varandas, A J C

2015-02-26

188

Energy saving potential of office equipment power management  

Microsoft Academic Search

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

Kaoru Kawamoto; Yoshiyuki Shimoda; Minoru Mizuno

2004-01-01

189

Investigation of contact electrification based broadband energy harvesting mechanism using elastic PDMS microstructures  

NASA Astrophysics Data System (ADS)

Triboelectric energy harvesting has recently garnered a lot of interest because of its easy fabrication and high power output. Contact electrification depends on the chemical properties of contacting materials. Another important factor in contact electrification mechanism is surfaces’ elastic and topographical characteristics. One of the biggest limitations of resonant mechanism based devices is their narrow operating bandwidth. This paper presents a broadband mechanism which utilizes stiffness induced in the cantilever motion due to contact between two triboelectric surfaces. We have conducted experiments using polydimethylsiloxane (PDMS) micropad patterns to study the effect of micropad array configuration on the performance of triboelectric energy harvesting devices. The maximum power output measured from the device was observed to be 0.69??W at an acceleration of 1?g. Due to the non-linearity introduced by contact separation mechanism, the bandwidth of the triboelectric energy harvester was observed to be increased by 63% at an acceleration level of 1?g. A hybrid energy harvesting mechanism has also been demonstrated by compounding the triboelectric energy harvester with a piezoelectric bimorph.

Dhakar, Lokesh; Tay, F. E. H.; Lee, Chengkuo

2014-10-01

190

The Wind Energy Potential of Iceland  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

191

Analysis of diffractive features in elastic scattering of {sup 7}Li by different target nuclei at different energies  

SciTech Connect

The diffractive features of angular distribution have been investigated by analyzing the experimental data for a set of elastic scattering processes of {sup 7}Li by different target nuclei at different laboratory energies. Both Frahn-Venter and McIntyre models are used to analyze experimental data of angular distribution for elastic scattering processes. The theoretical models can reasonably reproduce the general pattern of the data. Some geometrical parameters for colliding nuclei have been obtained from the elastic scattering processes. It is found that interpretation of the diffractive features of the data is model-independent. The values of extracted parameters, from adopted models, are found comparable to each other and to those of others. The total reaction cross section is correlated to the incident laboratory energy for each scattering and values of total reaction cross section are found comparable with those of others.

Badran, R. I.; Masri, Dana Al [Physics Department, Faculty of Sciences, The Hashemite University, Zarqa (Jordan)

2013-12-16

192

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

E-print Network

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.

L. V. Elnikova

2014-10-09

193

Antihydrogen-hydrogen elastic scattering at thermal energies using an atomic-orbital technique  

SciTech Connect

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.

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

194

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

SciTech Connect

Cross-sections for the elastic recoil of hydrogen isotopes, including tritium, have been measured for {sup 4}He{sup 2+} ions in the energy range of 9.0-11.6 MeV. These cross-sections have been measured at a scattering angle of 30{sup o} in the laboratory frame. Cross-sections were measured by allowing a {sup 4}He{sup 2+} beam to fall incident on solid targets of ErH{sub 2}, ErD{sub 2} and ErT{sub 2}, each of 500 nm nominal thickness and known areal densities of H, D, T and Er. The uncertainty in each cross-section is estimated to be {+-}3.2%.

Browning, James Frederick; Doyle, Barney Lee; Wampler, William R.; Banks, James Clifford

2003-06-01

195

The influence of elastic strain energy on the formation of coherent hexagonal phases  

NASA Astrophysics Data System (ADS)

The elastic strain energy function, Y (n), of coherent hexagonal phases has been derived for arbitrary directions, n, in a parent phase with arbitrary crystal structure. These calculations indicate that in all cases Y ( n) exhibits transverse isotropy about the c axis. As a result, Y (n) has a pronounced effect on the morphology of the precipitating structures. In the case of hexagonal inclusions, three possible optimum shapes in reciprocal space are identified: 1) a rod parallel to the c axis, 2) a plate perpendicular to the c axis, and 3) a hollow conical shape with the axis of revolution parallel to c. The precise precipitate shape can be predicted by identifying the direction n o which minimizes the strain energy function, Y (n). Evaluation of Y (n) for ? and ? MgZn2 precipitates in the ternary Al-Mg-Zn system correctly predicts the orientation and morphology of the particles. This method has also been extended to explore the morphology of the microstructure of hexagonal spinodal alloys. It is shown that the gradient energy term is generally anisotropic, and that together with the strain energy function, Y(n), has a strong influence on composition fluctuations. It is predicted that a one-dimensional periodic compositional variation along the [001] direction should be observed when Y [001] is a global minimum. In all other cases, the microstructure is complex and lacks periodicity.

Mayo, W. E.; Tsakalakos, T.

1980-10-01

196

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

SciTech Connect

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.

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

2014-05-14

197

Recent proton-antiproton low-energy data and the Paris N N potential  

SciTech Connect

We have readjusted the {ital short}-range part of the Paris nucleon-antinucleon potential taking into account the new {ital p{bar p}} data, in particular those from the CERN Low-Energy Antiproton Ring. Discrepancies between results of our earlier version and experimental data on charge-exchange cross sections are removed. Moreover, a significant improvement of the fit to cross sections and especially polarization in elastic scattering is obtained. Our analysis shows that the low-energy {ital p{bar p}} data and the short-range {ital N{bar N}} interaction are strongly dependent on each other.

Pignone, M.; Lacombe, M.; Loiseau, B.; Vinh Mau, R. (Istituto Nazionale di Fisica Nucleare, Sezione di Torino, 10125 Torino (Italy) Division de Physique Theorique, Institut de Physique Nucleaire (91406 Orsay CEDEX) Laboratoire de Physique Theorique et Particules Elementaires, Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris CEDEX 05 (France))

1991-10-28

198

Heparinized PLLA/PLCL nanofibrous scaffold for potential engineering of small-diameter blood vessel: Tunable elasticity and anticoagulation property.  

PubMed

The success of tissue engineered vascular grafts depends greatly on the synthetic tubular scaffold, which can mimic the architecture, mechanical, and anticoagulation properties of native blood vessels. In this study, small-diameter tubular scaffolds were fabricated with different weight ratios of poly(l-lactic acid) (PLLA) and poly(l-lactide-co-?-caprolactone) (PLCL) by means of thermally induced phase separation technique. To improve the anticoagulation property of materials, heparin was covalently linked to the tubular scaffolds by N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide coupling chemistry. The as-prepared PLLA/PLCL scaffolds retained microporous nanofibrous structure as observed in the neat PLLA scaffolds, and their structural and mechanical properties can be fine-tuned by changing the ratio of two components. The scaffold containing 60% PLCL content was found to be the most promising scaffold for engineering small-diameter blood vessel in terms of elastic properties and structural integrity. The heparinized scaffolds showed higher hydrophilicity, lower protein adsorption ability, and better in vitro anticoagulation property than their untreated counterparts. Pig iliac endothelial cells seeded on the heparinized scaffold showed good cellular attachment, spreading, proliferation, and phenotypic maintenance. Furthermore, the heparinized scaffolds exhibited neovascularization after subcutaneous implantation into the New Zealand white rabbits for 1 and 2 months. Taken together, the heparinized PLLA/PLCL nanofibrous scaffolds have the great potential for vascular tissue engineering application. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1784-1797, 2015. PMID:25196988

Wang, Weizhong; Hu, Jinwei; He, Chuanglong; Nie, Wei; Feng, Wei; Qiu, Kexin; Zhou, Xiaojun; Gao, Yu; Wang, Guoqing

2015-05-01

199

The energy eigenvalues of hyperbolical potential functions  

Microsoft Academic Search

The energy eigenvalues E(upsilo) of the hyperbolical potential functions V(r)± = hcA{delta - sigma(coth alpha(r - r0))±1}2 were determined with a semiclassical procedure (the Bohr-Sommerfeld quantization condition) and a quantum-mechanical method (the Schrödinger equation). The resulting term values G(upsilo) = E(upsilo)\\/hc are different: G(upsilo) = De - A{deltasigma(s + upsilo + 1\\/2)-1 - (s + upsilo + 1\\/2)}2 (for upsilo

Dag Schiöberg

1986-01-01

200

Theoretical studies of potential energy surfaces  

SciTech Connect

The goal of this program is to calculate accurate potential energy surfaces (PES) for both reactive and nonreactive systems. To do this the electronic Schrodinger equation must be solved. Our approach to this problem starts with multiconfiguration self-consistent field (MCSCF) reference wavefunctions. These reference wavefunctions are designed to be sufficiently flexible to accurately describe changes in electronic structure over a broad range of geometries. Electron correlation effects are included via multireference, singles and doubles configuration interaction (MRSDCI) calculations. With this approach, the authors are able to provide useful predictions of the energetics for a broad range of systems.

Harding, L.B. [Argonne National Laboratory, IL (United States)

1993-12-01

201

Bulk elastic moduli and solute potentials in leaves of freshwater, coastal and marine hydrophytes. Are marine plants more rigid?  

PubMed Central

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

Touchette, Brant W.; Marcus, Sarah E.; Adams, Emily C.

2014-01-01

202

Bulk elastic moduli and solute potentials in leaves of freshwater, coastal and marine hydrophytes. Are marine plants more rigid?  

PubMed

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

Touchette, Brant W; Marcus, Sarah E; Adams, Emily C

2014-01-01

203

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

E-print Network

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.

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

204

Strong energy dependence of the optical potential for 32S+58,64Ni near the Coulomb barrier  

Microsoft Academic Search

The elastic scattering of 32S+ 58,64Ni was measured at sulfur beam energies of 82, 88, 91, 93, 98, 102.5, 108, and 150 MeV. Evidence is found for a marked energy dependence of the optical potential at the strong-absorption radii around the Coulomb barrier, in good agreement with parallel information extracted from the fusion cross sections for the same systems.

A. M. Stefanini; D. Bonamini; A. Tivelli; G. Montagnoli; G. Fortuna; Y. Nagashima; S. Beghini; C. Signorini; A. Derosa; G. Inglima; M. Sandoli; G. Cardella; F. Rizzo

1987-01-01

205

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

NASA Astrophysics Data System (ADS)

Cross sections at low energies for vibrationally elastic and inelastic scattering, as well as electron attachment to SF6 , have been calculated using a multichannel effective range theory (ERT) with complex boundary conditions. The most active vibrational modes, the totally symmetric mode ?1 and the infrared active mode ?3 , have been included in the calculation. The ERT parameters were fitted to reproduce the experimental total and attachment cross sections. Differential elastic and vibrational excitation cross sections have been measured at 30° and 135° using a spectrometer with hemispherical analyzers. The calculation reproduces correctly the magnitudes and shapes of the differential elastic and ?1 , ?3 , and 2?1 excitation cross sections, in particular the sharp structures at vibrational thresholds. The s - and p -wave phase shifts obtained in the present analysis differ from those recently derived by Field [Phys. Rev. A, 69, 052716 (2004)].

Fabrikant, Ilya I.; Hotop, Hartmut; Allan, Michael

2005-02-01

206

Elastic and Irreversible Energies of a Two-Stage Martensitic Transformation in NiTi Utilizing Calorimetric Measurements  

NASA Astrophysics Data System (ADS)

Elastic energy and irreversible energy are quantified based on calorimetric measurements. We analyze energetics for each stage of the stress-free, thermally induced two-stage phase transformation A ? R ? B19' in an aged Ni-rich NiTi shape memory alloy. Heating/cooling rates are imposed from 1 K/min up to 100 K/min. We compare energetic analysis after multiple thermal cycles to virgin ( i.e., first-cycle) material. Fundamental thermodynamic formulations are applied from two perspectives: the free energy change d G, and the rate of change of free energy expressed as d G/d f m. Two measures of irreversible contributions are defined: the difference between the forward and reverse transformation heats, and the product of the entropy and the thermal hysteresis. Higher values are determined for the former. For scan rates of 10 K/min and greater, the energetic values become relatively stable. Substantial variations are evident at 1, 5, and 10 K/min. The scan rate impacts the elastic strain energy and irreversible energy of the B19' markedly compared with the R-phase transition. The findings are rationalized considering morphologic changes at the lower scan rates and the impacts on elastic and irreversible energies.

Lanba, Asheesh; Hamilton, Reginald F.

2014-06-01

207

Metabolic energy cost of action potential velocity.  

PubMed

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

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

2006-09-01

208

Assessment of wind energy potential in Poland  

NASA Astrophysics Data System (ADS)

The aim of the presentation is to show the suitability of using numerical model wind speed forecasts for the wind power industry applications in Poland. In accordance with the guidelines of the European Union, the consumption of wind energy in Poland is rapidly increasing. According to the report of Energy Regulatory Office from 30 March 2013, the installed capacity of wind power in Poland was 2807MW from 765 wind power stations. Wind energy is strongly dependent on the meteorological conditions. Based on the climatological wind speed data, potential energy zones within the area of Poland have been developed (H. Lorenc). They are the first criterion for assessing the location of the wind farm. However, for exact monitoring of a given wind farm location the prognostic data from numerical model forecasts are necessary. For the practical interpretation and further post-processing, the verification of the model data is very important. Polish Institute Meteorology and Water Management - National Research Institute (IMWM-NRI) runs an operational model COSMO (Consortium for Small-scale Modelling, version 4.8) using two nested domains at horizontal resolutions of 7 km and 2.8 km. The model produces 36 hour and 78 hour forecasts from 00 UTC, for 2.8 km and 7 km domain resolutions respectively. Numerical forecasts were compared with the observation of 60 SYNOP and 3 TEMP stations in Poland, using VERSUS2 (Unified System Verification Survey 2) and R package. For every zone the set of statistical indices (ME, MAE, RMSE) was calculated. Forecast errors for aerological profiles are shown for Polish TEMP stations at Wroc?aw, Legionowo and ?eba. The current studies are connected with a topic of the COST ES1002 WIRE-Weather Intelligence for Renewable Energies.

Starosta, Katarzyna; Linkowska, Joanna; Mazur, Andrzej

2014-05-01

209

Ab initio calculations on the free energy and high PT elasticity of face-centred-cubic iron  

Microsoft Academic Search

Ab initio finite temperature molecular dynamics simulations have been used to calculate the free energy and elasticity of face-centred cubic (fcc) iron at a state point representative of the Earth's inner core. Whilst the free energy of this phase is found to be higher than that of hexagonal-close-packed (hcp) iron, the difference is only 14 meV\\/atom. It is possible that

Lidunka Vo?adlo; Ian G. Wood; Dario Alfè; G. D. Price

2008-01-01

210

Energy potential of sugarcane and sweet sorghum  

SciTech Connect

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

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

1980-01-01

211

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

E-print Network

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.

Meisam Asgari

2015-02-09

212

Elastic energy and phase structure in a continuous spin Ising chain with applications to chiral homopolymers.  

PubMed

We present a numerical Monte Carlo analysis of the phase structure in a continuous spin Ising chain that describes chiral homopolymers. We find that depending on the value of the Metropolis temperature, the model displays the three known nontrivial phases of polymers: At low temperatures the model is in a collapsed phase, at medium temperatures it is in a random walk phase, and at high temperatures it enters the self-avoiding random walk phase. By investigating the temperature dependence of the specific energy we confirm that the transition between the collapsed phase and the random walk phase is a phase transition, while the random walk phase and self-avoiding random walk phase are separated from each other by a crossover transition. We propose that the model can be applied to characterize the statistical properties of protein folding. For this we compare the predictions of the model to a phenomenological elastic energy formula, proposed by J. Lei and K. Huang [e-print arXiv:1002.5013; Europhys. Lett. 88, 68004 (2009)] to describe folded proteins. PMID:21405680

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

2011-01-01

213

Phenomenon of Energy Focusing in Explosion Systems which Include High Modulus Elastic Elements  

NASA Astrophysics Data System (ADS)

The results of experimental studies of physical reasons and conditions of the phenomenon of energy focusing in explosion systems including high modulus elastic elements are presented. Experiments were conducted to study the conditions of this phenomenon for TG-40/60, SEP and Composition B. For each HE a number of experiments has been conducted for various heights of silicon carbide inserts. Presence or absence of a hole in the steel specimen was determined. Also a number of frame-by-frame recordings of the process with record step of 1 ?s have been performed. It is shown that the energy focusing phenomenon is reproduced for various high explosives. The phenomenon is observed in the conditions close to critical conditions of detonation transfer from an active to a passive HE charge. The best conditions for the phenomenon were observed for TG-40/60 for ceramic insert heights of 16.5 mm, 18 mm and 19.5-mm. Physical reason of focusing process is the propagation of a concave detonation wave into highly compressed HE and the formation of a Mach stem on the axis of HE charge.

Balagansky, I.; Hokamoto, K.; Manikandan, P.; Matrosov, A.; Stadnichenko, I.; Miyoshi, H.

2009-12-01

214

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

SciTech Connect

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

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

2010-04-26

215

Spectroscopy of reactive potential energy surfaces Daniel M. Neumark  

E-print Network

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

Neumark, Daniel M.

216

Communication: Certifying the potential energy landscape  

NASA Astrophysics Data System (ADS)

It is highly desirable for numerical approximations to stationary points for a potential energy landscape to lie in the corresponding quadratic convergence basin. 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 certification. Here, we apply Smale's ?-theory to stationary points, providing a certification serving 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 ?-theory can be used to certify all the known minima and transition states of Lennard-Jones LJN atomic clusters for N = 7, …, 14.

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

2013-05-01

217

Certification and the potential energy landscape.  

PubMed

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

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

2014-06-14

218

Certification and the potential energy landscape  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

219

Nov. 30, 2010 Potential Energy Surfaces for Simulating Complex Chemical  

E-print Network

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

Truhlar, Donald G

220

Feature Article Exploring Potential Energy Surfaces for Chemical  

E-print Network

Feature Article Exploring Potential Energy Surfaces for Chemical Reactions: An Overview of Some series of programs.2 The focus is on potential energy surfaces obtained by quantum chemical methods 48202 Received 25 July 2002; Accepted 4 November 2002 Abstract: Potential energy surfaces form a central

Schlegel, H. Bernhard

221

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

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

222

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

NASA Astrophysics Data System (ADS)

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

Yokoyama, Naoto; Takaoka, Masanori

2014-12-01

223

Single-wavenumber Representation of Nonlinear Energy Spectrum in Elastic-Wave Turbulence of {F}öppl-von {K}ármán Equation: Energy Decomposition Analysis and Energy Budget  

E-print Network

A single-wavenumber representation of nonlinear energy spectrum, i.e., stretching energy spectrum is found in elastic-wave turbulence governed by the F\\"oppl-von K\\'arm\\'an (FvK) equation. The representation enables energy decomposition analysis in the wavenumber space, and analytical expressions of detailed energy budget in the nonlinear interactions are obtained for the first time in wave turbulence systems. We numerically solved the FvK equation and observed the following facts. Kinetic and bending energies are comparable with each other at large wavenumbers as the weak turbulence theory suggests. On the other hand, the stretching energy is larger than the bending energy at small wavenumbers, i.e., the nonlinearity is relatively strong. The strong correlation between a mode $a_{\\bm{k}}$ and its companion mode $a_{-\\bm{k}}$ is observed at the small wavenumbers. Energy transfer shows that the energy is input into the wave field through stretching-energy transfer at the small wavenumbers, and dissipated through the quartic part of kinetic-energy transfer at the large wavenumbers. A total-energy flux consistent with the energy conservation is calculated directly by using the analytical expression of the total-energy transfer, and the forward energy cascade is observed clearly.

Naoto Yokoyama; Masanori Takaoka

2014-12-09

224

Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo  

PubMed Central

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

Roach, Neil T.; Venkadesan, Madhusudhan; Rainbow, Michael J.; Lieberman, Daniel E.

2013-01-01

225

Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo.  

PubMed

Some primates, including chimpanzees, throw objects occasionally, but only humans regularly throw projectiles with high speed and accuracy. Darwin noted that the unique throwing abilities of humans, which were made possible when bipedalism emancipated the arms, enabled foragers to hunt effectively using projectiles. 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 of when, how and why hominins evolved the ability to generate high-speed throws. Here we use experimental studies of humans throwing projectiles to show that our 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 2?million years ago in the species Homo erectus. Taking into consideration archaeological evidence suggesting that hunting activity intensified around this time, we conclude that selection for throwing as a means to hunt probably had an important role in the evolution of the genus Homo. PMID:23803849

Roach, Neil T; Venkadesan, Madhusudhan; Rainbow, Michael J; Lieberman, Daniel E

2013-06-27

226

Elastic Circuits  

Microsoft Academic Search

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

Josep Carmona; Jordi Cortadella; Michael Kishinevsky; Alexander Taubin

2009-01-01

227

Elastic scattering of {sup 16}O+{sup 16}O at energies E/A between 5 and 8 MeV  

SciTech Connect

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.

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

228

Channel coupling effect and important role of imaginary part of coupling potential for high-energy heavy-ion scatterings  

NASA Astrophysics Data System (ADS)

The recent works by the present authors and their collaborator predicted that the real part of heavy-ion optical potentials changes its character from attraction to repulsion around the incident energy per nucleon E/A= 200-300 MeV on the basis of the complex G-matrix interaction and the double-folding model (DFM) and revealed that the three-body force plays an important role there. In the present paper, we have analyzed the energy dependence of the coupling effect with the microscopic coupled channel (MCC) method and its relation to the elastic and inelastic-scattering angular distributions in detail in the case of the 12C + 12C system in the energy range of E/A= 100-400 MeV. The large channel coupling effect is clearly seen in the elastic cross section although the incident energies are enough high. The dynamical polarization potential (DPP) is derived to investigate the channel coupling effect. Moreover, we analyze the effect of the imaginary part of the coupling potential on elastic and inelastic cross sections.

Furumoto, T.; Sakuragi, Y.

2013-01-01

229

ASSESSMENT OF ENERGY RECOVERY POTENTIAL OF INDUSTRIAL COMBUSTION EQUIPMENT  

EPA Science Inventory

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...

230

Differential elastic electron scattering cross sections for CCl4 by 1.5-100 eV energy electron impact.  

PubMed

We report absolute elastic differential, integral and momentum transfer cross sections for electron interactions with CCl(4). The incident electron energy range is 1.5-100 eV, and the scattered electron angular range for the differential measurements varies from 15°-130°. The absolute scale of the differential cross section was set using the relative flow technique with helium as the reference species. Comparison with previous total cross sections shows good agreement. Atomic-like behaviour in this scattering system is shown here for the first time, and is further investigated by comparing the CCl(4) elastic cross sections to recent results on the halomethanes and atomic chlorine at higher impact energies [H. Kato, T. Asahina, H. Masui, M. Hoshino, H. Tanaka, H. Cho, O. Ingólfsson, F. Blanco, G. Garcia, S. J. Buckman, and M. J. Brunger, J. Chem. Phys. 132, 074309 (2010)]. PMID:22191877

Limão-Vieira, P; Horie, M; Kato, H; Hoshino, M; Blanco, F; García, G; Buckman, S J; Tanaka, H

2011-12-21

231

Predicting the Drop Performance of Solder Joints by Evaluating the Elastic Strain Energy from High-Speed Ball Pull Tests  

NASA Astrophysics Data System (ADS)

Despite being expensive and time consuming, board-level drop testing has been widely used to assess the drop or impact resistance of the solder joints in handheld microelectronic devices, such as cellphones and personal digital assistants (PDAs). In this study, a new test method, which is much simpler and quicker, is proposed. The method involves evaluating the elastic strain energy and relating it to the impact resistance of the solder joint by considering the Young’s modulus of the bulk solder and the fracture stress of the solder joint during a ball pull test at high strain rates. The results show that solder joints can be ranked in order of descending elastic strain energy as follows: Sn-37Pb, Sn-1Ag-0.5Cu, Sn-3Ag-0.5Cu, and Sn-4Ag-0.5Cu. This order is consistent with the actual drop performances of the samples.

You, Taehoon; Kim, Yunsung; Kim, Jina; Lee, Jaehong; Jung, Byungwook; Moon, Jungtak; Choe, Heeman

2009-03-01

232

Energy evolution of the large-t elastic scattering and its correlation with multiparticle production  

SciTech Connect

It is emphasized that the collective dynamics associated with color confinement is dominating over a point-like mechanism related to a scattering of the proton constituents at the currently available values of the momentum transferred in proton elastic scattering at the LHC. Deep-elastic scattering and its role in the dissimilation of the absorptive and reflective asymptotic scattering mechanisms are discussed with emphasis on the experimental signatures associated with the multiparticle production processes.

Troshin, S. M. [Institute for High Energy Physics, Protvino, Moscow Region, 142281 (Russian Federation)

2013-04-15

233

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

Microsoft Academic Search

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

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

2000-01-01

234

Free energy perturbation method for measuring elastic constants of liquid crystals  

NASA Astrophysics Data System (ADS)

There is considerable interest in designing liquid crystals capable of yielding specific morphological responses in confined environments, including capillaries and droplets. The morphology of a liquid crystal is largely dictated by the elastic constants, which are difficult to measure and are only available for a handful of substances. In this work, a first-principles based method is proposed to calculate the Frank elastic constants of nematic liquid crystals directly from atomistic models. These include the standard splay, twist and bend deformations, and the often-ignored but important saddle-splay constant. The proposed method is validated using a well-studied Gay-Berne(3,5,2,1) model; we examine the effects of temperature and system size on the elastic constants in the nematic and smectic phases. We find that our measurements of splay, twist, and bend elastic constants are consistent with previous estimates for the nematic phase. We further outline the implementation of our approach for the saddle-splay elastic constant, and find it to have a value at the limits of the Ericksen inequalities. We then proceed to report results for the elastic constants commonly known liquid crystals namely 4-pentyl-4'-cynobiphenyl (5CB) using atomistic model, and show that the values predicted by our approach are consistent with a subset of the available but limited experimental literature.

Joshi, Abhijeet

235

Correlation between the high-frequency elastic modulus and the interparticle interaction potential in zirconium oxide colloidal suspensions  

Microsoft Academic Search

In this work, we study the high-frequency elastic modulus of aqueous suspensions made with two kinds of zirconium oxide particles, one commercially available and the other synthesized as monodisperse spheres. The effect of volume fraction of solid, ionic strength (sodium chloride as indifferent electrolyte) and particle geometry is taken into account in the study on this viscoelastic property of the

David Megías-Alguacil

2005-01-01

236

Elastic interaction energy between a silicon interstitial and a carbon substitutional in a silicon crystal  

NASA Astrophysics Data System (ADS)

The strain interaction energy between a silicon interstitial and a carbon substitutional in a silicon crystal was modeled by a continuum Green’s function method and by atomistic simulation. The interaction energy is proportional to d-3 , where d is separation distance between the defects. The pair interaction energy was found to be less than 0.04meV for d>6nm increasing to more than about 0.1meV for d<3nm . The energies are unlikely to influence the diffusional behavior of the defects except at distances of one or two unit cells. The potential between the point defects is repulsive if they are oriented along the (100) crystal axis, but attractive if they are positioned along (110) or (111).

Christmas, Ursula M. E.; Faux, David A.; Cowern, Nicholas E. B.

2007-11-01

237

Non-contacting transfer of elastic energy into explosive simulants for dynamic property estimation  

NASA Astrophysics Data System (ADS)

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.

Greeney, Nathan S.; Strovink, Kurt M.; Scales, John A.; Jessop, Andrew M.; Stuart Bolton, J.; Watson, Christopher C.; Adams, Douglas E.

2014-05-01

238

Non-contacting transfer of elastic energy into explosive simulants for dynamic property estimation  

SciTech Connect

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.

Greeney, Nathan S.; Strovink, Kurt M.; Scales, John A. [Physics Department, Colorado School of Mines, Golden, Colorado 80401 (United States); Jessop, Andrew M.; Stuart Bolton, J. [Ray W. Herrick Laboratories, Purdue University, West Lafayette, Indiana 47907-2099 (United States); Watson, Christopher C.; Adams, Douglas E. [Purdue Center for Systems Integrity, Purdue University, Lafayette, Indiana 47905 (United States)

2014-05-21

239

The energy release rate of a pressurized crack in soft elastic materials: effects of surface tension and large deformation.  

PubMed

In this paper we present a theoretical study on how surface tension affects fracture of soft solids. In classical fracture theory, the resistance to fracture is partly attributed to the energy required to create new surfaces. Thus, the energy released to the crack tip must overcome the surface energy in order to propagate a crack. In soft materials, however, surface tension can cause significant deformation and can reduce the energy release rate for crack propagation by resisting the stretch of crack surfaces. We quantify this effect by studying the inflation of a penny-shaped crack in an infinite elastic body with applied pressure. To avoid numerical difficulty caused by singular fields near the crack tip, we derived an expression for the energy release rate which depends on the applied pressure, the surface tension, the inflated crack volume and the deformed crack area. This expression is evaluated using a newly developed finite element method with surface tension elements. Our calculation shows that, when the elasto-capillary number ? ? ?/Ea is sufficiently large, where ? is the isotropic surface tension, E is the small strain Young's modulus and a is the initial crack radius, both the energy release rate and the crack opening displacement of an incompressible neo-Hookean solid are significantly reduced by surface tension. For a sufficiently high elasto-capillary number, the energy release rate can be negative for applied pressure less than a critical amount, suggesting that surface tension can cause crack healing in soft elastic materials. PMID:25140489

Liu, Tianshu; Long, Rong; Hui, Chung-Yuen

2014-10-21

240

Potential of renewable energy systems in China  

Microsoft Academic Search

Along with high-speed economic development and increasing energy consumption, the Chinese Government faces a growing pressure to maintain the balance between energy supply and demand. In 2009, China has become both the largest energy consumer and CO2 emitting country in the world. In this case, the inappropriate energy consumption structure should be changed. As an alternative, a suitable infrastructure for

Wen Liu; Henrik Lund; Brian Vad Mathiesen; Xiliang Zhang

2011-01-01

241

Transportation Energy Use and Conservation Potential  

ERIC Educational Resources Information Center

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

Hirst, Eric

1973-01-01

242

An Iterative Global Optimization Algorithm for Potential Energy Minimization  

E-print Network

[1]. The algorithm is tested on two different potential energy functions. The first function algorithms considering the potential functions as sample global optimization test problems. In [12An Iterative Global Optimization Algorithm for Potential Energy Minimization N. P. Moloi and M. M

243

Potential contribution of biomass to the sustainable energy development  

Microsoft Academic Search

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

M. Fatih Demirbas; Mustafa Balat; Havva Balat

2009-01-01

244

Re-examining Potential for Geothermal Energy in United States  

Microsoft Academic Search

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

Randy Showstack

2003-01-01

245

Biomass energy: the scale of the potential resource  

Microsoft Academic Search

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

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

2007-01-01

246

Biomass energy: the scale of the potential resource  

E-print Network

Biomass energy: the scale of the potential resource Christopher B. Field1 , J. Elliott Campbell1 Avenue, Livermore, CA 94550, USA Increased production of biomass for energy has the potential to offset resources and decrease food security. The net effect of biomass energy agriculture on climate could

247

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

248

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

PubMed Central

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

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

2015-01-01

249

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

250

ELASTICITYELASTICITY Elasticity  

E-print Network

? Elasticity Plasticity Fracture Fatigue Mechanical Behaviour Creep Elongation at constant load at High Elasticity Linear Non-linear E.g. Al deformed at small strains E.g. deformation of an elastomer like rubber

Subramaniam, Anandh

251

Layout design optimization for magneto-electro-elastic laminate composites for maximized energy conversion under mechanical loading  

NASA Astrophysics Data System (ADS)

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.

Sun, Kyung Ho; Kim, Yoon Young

2010-05-01

252

Test of microscopic optical model potentials for neutron elastic scattering at 14.6 MeV over a wide mass range  

NASA Astrophysics Data System (ADS)

Differential cross sections for the elastic scattering of 14.6 MeV neutrons from 9Be, C, 27Al, Fe, 59Co, 89Y, 93Nb, In, 140Ce, 181Ta, 197Au, 208Pb, and 209Bi have been measured using a time-of-flight facility. The measured cross sections cover the angular range from 9.2° to 159°. Calculations have been carried out using two local microscopic optical potentials, based on the work of Jeukenne, Lejeune, and Mahaux, and of Brieva and Rook. Reasonably good agreement with the measurements is found over the whole mass range, with the Jeukenne-Lejeune-Mahaux potential giving systematically better agreement with the data. The quality of the results with the Jeukenne-Lejeune-Mahaux potential compares well with that obtained from phenomenological optical model calculations using global parameters.

Hansen, L. F.; Dietrich, F. S.; Pohl, B. A.; Poppe, C. H.; Wong, C.

1985-01-01

253

Evaluation of the Energy Saving Potential from Flue Gas Pressurization  

E-print Network

The potential for recovering energy from low pressure furnace flue products is limited when standard heat recovery equipment is utilized. Efficient energy recovery can be accomplished by providing a flue gas side pressure drop across a heat...

Stanton, E. H.

1980-01-01

254

Potential hydroelectric energy resources of Idaho  

Microsoft Academic Search

Data are compiled and presented on 1300 potential hydroelectric power sites in Idaho, on hydropower resource inventories and evaluations, and on existing hydroelectric facilities. The data include geographic location, head, and power capacity. (LCL)

C. C. Warnick; J. R. Filler; P. J. Vance

1981-01-01

255

Electron atomic scattering factors, Debye-Waller factors and the optical potential for high-energy electron diffraction.  

PubMed

High-energy electrons may be elastically and inelastically scattered by a solid. To a good approximation the effect of inelastic scattering on the elastically scattered electrons may be taken into account using the concept of the complex optical potential. The optical potential may be calculated using electron atomic scattering factors and Debye-Waller factors, which in turn can be evaluated numerically using Hartree Fock atomic wave functions and shell models of lattice dynamics. The numerical electron atomic scattering factors have been parameterized using five Gaussian functions for all the neutral atoms of the periodic table and for 106 important ions, and the temperature-dependent Debye-Waller B-factors have been fitted by using fourth degree polynomial regression fitting for 19 compounds with the sodium chloride structure, 5 compounds with the cesium chloride structure, 17 compounds with the zinc-blend structure and 68 elemental crystals. PMID:16076864

Peng, Lian-Mao

2005-06-01

256

Calculation of molecular free energies in classical potentials  

E-print Network

Free energy calculations in molecular simulations are used to predict the strength of molecular processes such as binding and solvation. We present an accurate and complete calculation of molecular free energies in standard classical potentials. In this method we transform the molecule by relaxing potential terms that depend on the coordinates of a group of atoms in that molecule and calculate the free energy difference associated with the transformation. Then, since the transformed molecule can be treated as non interacting systems, the free energy associated with these atoms is analytically or numerically calculated. We suggest the potential application of free energy calculation of chemical reactions in classical molecular simulations.

Farhi, Asaf

2015-01-01

257

The Potential for Wind Energy in Atlantic Canada  

E-print Network

of many renewable sources of energy, such as solar, biomass, hydroelectric, and wind. This paper considersThe Potential for Wind Energy in Atlantic Canada Larry Hughes and Sandy Scott Whale Lake Research World Renewable Energy Congress, Reading, September 1992. #12;Hughes/Scott: Wind Energy in Atlantic

Hughes, Larry

258

Energy conservation potential of surface modification technologies  

SciTech Connect

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

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

1985-09-01

259

Energy in America: Progress and Potential.  

ERIC Educational Resources Information Center

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

American Petroleum Inst., Washington, DC.

260

HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS  

SciTech Connect

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

PARSA,Z.

2000-04-07

261

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

E-print Network

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

262

Jumping sans legs: does elastic energy storage by the vertebral column power terrestrial jumps in bony fishes?  

PubMed

Despite having no obvious anatomical modifications to facilitate movement over land, numerous small fishes from divergent teleost lineages make brief, voluntary terrestrial forays to escape poor aquatic conditions or to pursue terrestrial prey. Once stranded, these fishes produce a coordinated and effective "tail-flip" jumping behavior, wherein lateral flexion of the axial body into a C-shape, followed by contralateral flexion of the body axis, propels the fish into a ballistic flight-path that covers a distance of multiple body lengths. We ask: how do anatomical structures that evolved in one habitat generate effective movement in a novel habitat? Within this context, we hypothesized that the mechanical properties of the axial skeleton play a critical role in producing effective overland movement, and that tail-flip jumping species demonstrate enhanced elastic energy storage through increased body flexural stiffness or increased body curvature, relative to non-jumping species. To test this hypothesis, we derived a model to predict elastic recoil work from the morphology of the vertebral (neural and hemal) spines. From ground reaction force (GRF) measurements and high-speed video, we calculated elastic recoil work, flexural stiffness, and apparent material stiffness of the body for Micropterus salmoides (a non-jumper) and Kryptolebias marmoratus (adept tail-flip jumper). The model predicted no difference between the two species in work stored by the vertebral spines, and GRF data showed that they produce the same magnitude of mass-specific elastic recoil work. Surprisingly, non-jumper M. salmoides has a stiffer body than tail-flip jumper K. marmoratus. Many tail-flip jumping species possess enlarged, fused hypural bones that support the caudal peduncle, which suggests that the localized structures, rather than the entire axial skeleton, may explain differences in terrestrial performance. PMID:24388492

Ashley-Ross, Miriam A; Perlman, Benjamin M; Gibb, Alice C; Long, John H

2014-02-01

263

Atomistic potentials based energy flux integral criterion for dynamic adiabatic shear banding  

NASA Astrophysics Data System (ADS)

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.

Xu, Yun; Chen, Jun

2015-02-01

264

Methane hydrates potential as a future energy source  

Microsoft Academic Search

Gas hydrates are crystalline solids that form from mixtures of water and light natural gases such as methane, carbon dioxide, ethane, propane and butane. They are of considerable interest for their potential as an energy resource and for their potential role in global climate change. From an energy resource point of view, the enormous amounts of methane hydrate under the

Sang-Yong Lee; Gerald D. Holder

2001-01-01

265

Potential-energy surfaces for asymmetric heavy-ion reactions  

Microsoft Academic Search

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

P. Möller; J. R. Nix

1977-01-01

266

Potential Energy Sources Pose Mining Problem  

ERIC Educational Resources Information Center

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

Chemical and Engineering News, 1974

1974-01-01

267

Measurement of the elastic scattering /sup 12/C+/sup 28/Si at energies 56 MeV--69 MeV  

SciTech Connect

The angular distributions of the elastic scattering reaction /sup 12/C+/sup 28/Si have been measured at the energies 69.5 MeV, 66 MeV, 59 MeV, 56 MeV using a large area position sensitive ionization chamber. The experimental data are fitted in the framework of the optical model. The probable reasons of the oscillations and enhancement of the elastic scattering angular distributions are discussed.

SHEN Wen-qing; YIN Shu-zhi; GUO Zhong-yan; ZHU Yong-tai; CHEN Ju-shen; WU En-chiu; GUO Chi-di; FENG En-pu; XIE Yaun-xiang

1985-07-01

268

WKB corrections to the energy splitting in double well potentials  

E-print Network

By using the WKB quantization we deduce an analytical formula for the energy splitting in a double--well potential which is the usual Landau formula with additional quantum corrections. Then we analyze the accuracy of our formula for the double square well potential, the inverted harmonic oscillator and the quartic potential.

Marko Robnik; Luca Salasnich; Marko Vranicar

2000-03-29

269

An Iterative Global Optimization Algorithm for Potential Energy Minimization  

E-print Network

[1]. The algorithm is tested on two different potential energy functions. The first function algorithms considering the potential functions as sample global optimization test problems. In [12 the potential functions as sample global optimization problems only for testing our algorithm. We do

270

Energy sector and wind energy potential in Turkey  

Microsoft Academic Search

Turkey has very limited indigenous energy resources and has to import around 65% of primary energy to meet her needs. It is a large importer of primary energy despite having ample renewable energy sources.Turkey’s vibrant economy has led to increased energy demand in recent years. This situation is expected to continue in the near future because its economy is dependent

R. Tugrul Ogulata

2003-01-01

271

t dependence of the slope of the high energy elastic pp cross section  

NASA Astrophysics Data System (ADS)

We consider the main factors which cause the variation of the value of the local slope of the elastic pp cross section B(t)=d[ln (d{{? }el}(pp)/dt]/dt with t. Namely, we discuss the role of the pion loop insertion in the pomeron trajectory, the t-dependence of the pomeron–nucleon coupling and the role of the eikonalization of the proton–proton amplitude in both the one- and two-channel eikonal models.

Khoze, V. A.; Martin, A. D.; Ryskin, M. G.

2015-02-01

272

Biomass energy in China and its potential  

Microsoft Academic Search

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

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

2001-01-01

273

Renewable energy potential and utilization in Turkey  

Microsoft Academic Search

Renewable energy sources have been important for humans since the beginning of civilisation. For centuries, and in many ways, biomass has been used for heating, and cooking. Many centuries ago, mankind was already utilizing the clearly visible power of water for mechanical drive purposes, as was also the case with wind. Today, water mills are still used in our villages,

Kamil Kaygusuz; Ahmet Sar?

2003-01-01

274

Solar Energy: Potential Powerhouse for Jobs  

ERIC Educational Resources Information Center

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

McCallion, Tom

1976-01-01

275

Nudged-elastic band method with two climbing images: Finding transition states in complex energy landscapes a)  

NASA Astrophysics Data System (ADS)

The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with a serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, then C2-NEB finds it too. However, improved stability of C2-NEB makes it suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS, but also guarantees, by construction, that the climbing images approach it from the opposite sides along the MEP. In addition, C2-NEB provides an accuracy estimate from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB.

Zarkevich, Nikolai A.; Johnson, Duane D.

2015-01-01

276

Dual energy time reversed elastic wave propagation and nonlinear signal processing for localisation and depth-profiling of near-surface defects: a simulation study.  

PubMed

Nonlinear Elastic Wave Spectroscopy (NEWS) relies on the activation of defects by wave energy that propagates through the medium. In general, the response of activated defects will not scale linearly with the excitation amplitude, and the resulting nonlinear signatures can be identified and used for quality inspection. The efficiency of NEWS based inspection methods is therefore intrinsically linked to the locally deposited activation energy at the defect zone and the ability to generate nonlinear signatures that exceed the noise level of acquisition. Time Reversal techniques allow focusing of high levels of energy in small areas, and are consequently very useful for the local activation of defected zones. In this report, numerical simulations are reported showing the potential of a combination consisting of dual energy reciprocal Time Reversal and nonlinearity filtering using the Scaling Subtraction Method. The method is applied to the detection of planar near-surface defects parallel to the surface in a 2D domain. The results are evaluated for sweep excitation at different frequency ranges; for point-like receiver as well as extended transducers, and for in-plane as well as out-of-plane focusing. The observable nonlinear response at the surface is linked to an effective nonlinearity within the medium based on the defect geometry and the distribution of the local stresses. PMID:21714981

Janssen, Els N; Van Den Abeele, Koen

2011-12-01

277

A Nanoscale Simulation Study of Elastic Properties of Gaspeite  

NASA Astrophysics Data System (ADS)

The study of structural and mechanical properties of carbonate rock is an interesting subject in engineering and its different applications. In this paper, the crystal structure of gaspeite (NiCO3) is investigated by carrying out molecular dynamics simulations based on energy minimization technique using an interatomic interaction potential. At first, we focus on the structural properties of gaspeite mineral. And then, the elastic properties are calculated, including the elastic constants, bulk modulus, shear modulus, the S- and P-wave velocities. In the next part of this paper, the pressure effect will be studied on the structural and elastic properties of NiCO3 at high pressure.

Benazzouz, Brahim-Khalil

2015-02-01

278

Calculation of Average Collision Cross Sections of Low Energy for Elastic e-Ar Scattering Using MERT4  

NASA Astrophysics Data System (ADS)

Cross sections in the very low energy range are also represented by the modified effective-range theory (MERT) for low-energy electron scattering from the rare gas (argon). Simulations using published (theoretical) phase shifts indicate that extended versions of the standard effective-range theory with four adjustable parameters are required to give an adequate description of the phase shifts for argon. A four-parameter MERT fit gives a good representation of a recent electron-argon (e-Ar) total cross section experiment at energies less than 10.0 eV. Cross section Q(l) (E) for collision in dilute gases is given for any order l. Here Q(l) (E) are presented for l = 1. . .6. We present calculations for the elastic cross sections for electron scattering from argon. The improvement in the agreement between our theoretical calculations and the experimental measurements in the case of argon in scattering calculations are showed. Differential scattering experiments have been performed for the systems e-Ar in the energy range E = 0-10 eV and the angular range ? = 0-20° using a crossed-beam arrangement. Differential and integrated cross sections for the elastic scattering of low- and intermediate-energy (0-50 eV) electrons by argon atoms are calculated. For each impact energy, the phase shifts of the lower partial waves are obtained exactly by numerical integration of the radial equation. Transport coefficients of argon plasma are requested exactly, which is why we calculated the average collision cross sections for s = 1. . .11, l = 1. . .6.

Hassanpour, S.; Nguyen-Kuok, S.; Nguyen-Kuok

2015-01-01

279

Turkey's Renewable Energy Sources: Part 2. Potential and Utilization  

Microsoft Academic Search

In Turkey, renewable energy sources (RESs) production is the second biggest production source after total coal production. About two-thirds of the need of the RESs is met by biomass, while the remaining is mainly met by hydroelectric energy. This article addresses both potential and utilization relating to Turkey's RESs such as hydroelectric, solar, geothermal, wind energies and biomass, while these

ARIF HEPBASLI; ONDER OZGENER

2004-01-01

280

Potential of renewable energy development for water desalination in Tunisia  

Microsoft Academic Search

Potential renewable energy sources, which can be harnessed toward brackish and seawater desalination in Tunisia, have been evaluated. These sources of energy, mainly: solar, wind and geothermal, have been identified throughout the country and their suitability for coupling with different desalting technologies have been investigated. Renewable energies are expected to have a flourishing future and an important role in the

F Benjemaa; I Houcine; M. H Chahbani

1999-01-01

281

Ocean thermal energy: Potentials and pitfalls  

Microsoft Academic Search

Thermal energy in vast reaches of the world's oceans lies waiting to be tapped by a fuel?hungry world. The United States— the one heavily industrialized nation with “OTEC”; waters lapping its shores—is actively developing the technology; Japan and a European consortium are also pressing forward. The resource may be of practical value soon to favorably situated islands (e.g., Hawaii, Puerto

David L. Hurwood

1981-01-01

282

Periodic Discrete Energy for Long-Range Potentials  

E-print Network

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.

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

2014-12-11

283

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

SciTech Connect

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

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

2011-11-15

284

Mechanism of resilin elasticity.  

PubMed

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

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

2012-01-01

285

Full-potential calculation of the structural, elastic, electronic and magnetic properties of XFeO 3 (X=Sr and Ba) perovskite  

NASA Astrophysics Data System (ADS)

First-principles study of the structural, elastic, magnetic and electronic properties of the cubic perovskite SrFeO 3 and BaFeO 3 has been performed using the full-potential linear muffin-tin orbital (FP-LMTO) method within the local spin density approximation (LSDA). The calculated equilibrium lattice constant of SrFeO 3 is in good agreement with the available theoretical results. The independent elastic constants Cij, bulk modulus B and its pressure derivatives B', Shear modulus G, Young’s modulus E and Poisson’s ratio ? are obtained for both compounds. From the analysis of the ratio of shear to bulk modulus, it is found that SrFO 3 (BaFeO 3) is ductile (brittle) in nature. Band structures, total and partial densities of states show that the orbitals formed by Fe-O band have a primary importance in the determination of the electronic properties of the studied compounds. The calculated magnetic properties show that the magnetic moment of Fe is much higher and the contribution of the (Sr, Ba) and O elements to the magnetic moment is negligible.

Rached, H.; Rached, D.; Rabah, M.; Khenata, R.; Reshak, Ali H.

2010-09-01

286

Energy savings potential from energy-conserving irrigation systems  

SciTech Connect

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

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

1982-11-01

287

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

E-print Network

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

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

2010-08-26

288

Elastic energy storage in b-sheets with application to F1-ATPase Received: 26 December 2002 / Revised: 11 March 2003 / Accepted: 4 April 2003 / Published online: 3 September 2003  

E-print Network

ARTICLE Elastic energy storage in b-sheets with application to F1-ATPase Received: 26 December 2002) of elastic energy is stored in the b-sheet as the b-subunit undergoes its hinge bending motion, in good to deduce the relative free energies of each equilibrated structure. This allows us to determine the free

Sun, Sean

289

New approach to calculating the potential energy of colliding nuclei  

SciTech Connect

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.

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

2014-12-15

290

Semiclassical energy levels and the corresponding potentials in nonhydrogenic ions  

NASA Astrophysics Data System (ADS)

A semiclassical expression is derived for the potential seen by an nl-shell electron in a nonhydrogenic ion. Corresponding energies Enl are compared with experimental values and with results of self-consistent-field calculations.

Pankratov, P.; Meyer-Ter-Vehn, J.

1992-11-01

291

Proton-proton elastic scattering at the LHC energy of {\\surd} = 7 TeV  

E-print Network

Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at {\\surd}s = 7 TeV in dedicated runs with the Roman Pot detectors placed as close as seven times the transverse beam size (sbeam) from the outgoing beams. After careful study of the accelerator optics and the detector alignment, |t|, the square of four-momentum transferred in the elastic scattering process, has been determined with an uncertainty of d t = 0.1GeV p|t|. In this letter, first results of the differential cross section are presented covering a |t|-range from 0.36 to 2.5GeV2. The differential cross-section in the range 0.36 < |t| < 0.47 GeV2 is described by an exponential with a slope parameter B = (23.6{\\pm}0.5stat {\\pm}0.4syst)GeV-2, followed by a significant diffractive minimum at |t| = (0.53{\\pm}0.01stat{\\pm}0.01syst)GeV2. For |t|-values larger than ~ 1.5GeV2, the cross-section exhibits a power law behaviour with an exponent of -7.8_\\pm} 0.3stat{\\pm}0.1syst. When compared to predictions based on the different available models, the data show a strong discriminative power despite the small t-range covered.

The TOTEM Collaboration; G. Antchev; P. Aspell; I. Atanassov; V. Avati; J. Baechler; V. Berardi; M. Berretti; M. Bozzo; E. Brücken; A. Buzzo; F. Cafagna; M. Calicchio; M. G. Catanesi; C. Covault; M. Csanád; T. Csörgö; M. Deile; E. Dimovasili; M. Doubek; K. Eggert; V. Eremin; F. Ferro; A. Fiergolski; F. Garcia; S. Giani; V. Greco; L. Grzanka; J. Heino; T. Hilden; M. Janda; J. Kašpar; J. Kopal; V. Kundrát; K. Kurvinen; S. Lami; G. Latino; R. Lauhakangas; T. Leszko; E. Lippmaa; M. Lokají?ek; M. Lo Vetere; F. Lucas Rodríguez; M. Macrí; L. Magaletti; G. Magazzú; A. Mercadante; M. Meucci; S. Minutoli; F. Nemes; H. Niewiadomski; E. Noschis; T. Novak; E. Oliveri; F. Oljemark; R. Orava; M. Oriunno; K. Österberg; A. -L. Perrot; P. Palazzi; E. Pedreschi; J. Petäjäjärvi; J. Procházka; M. Quinto; E. Radermacher; E. Radicioni; F. Ravotti; E. Robutti; L. Ropelewski; G. Ruggiero; H. Saarikko; A. Santroni; A. Scribano; G. Sette; W. Snoeys; F. Spinella; J. Sziklai; C. Taylor; N. Turini; V. Vacek; M. Vítek; J. Welti; J. Whitmore

2011-10-06

292

Elastic and inelastic scattering of 240-MeV (6)Li ions from (40)Ca and (48)Ca and tests of a systematic optical potential  

E-print Network

.0116 ? 0.0012 0.0075 ? 0.0008 Q1 0.0164 ? 0.0017 0.0140 ? 0.0014 0.0083 ? 0.0008 Q2 0.0171 ? 0.0017 0.0126 ? 0.0013 0.0075 ? 0.0008 Present Q3 0.0164 ? 0.0017 0.0155 ? 0.0016 0.0105 ? 0.0011 L1 0.0171 ? 0.0017 0.0155 ? 0.0016 0.0094 ? 0.0009 L2 0... potentials TABLE V. Optical model parameters for 40Ca and 48Ca obtained from the systematic approach (Q1-Q3 and L1-L3) (see text). Parameters obtained by fitting the elastic scattering (DDF) are shown for comparison. Target label Nr Sr Wi ri0 ai Jw ? 2 ?r...

Chen, Krishichayan X.; Lui, Y. -W; Button, J.; Youngblood, David H.

2010-01-01

293

Potential energy surfaces of HgH 2  

NASA Astrophysics Data System (ADS)

Potential energy surfaces for HgH 2 have been calculated using a non-empirical relativistic effective core potential incorporating configuration interaction by means of the CIPSI algorithm. Core valence polarization and correlation energy are included via a perturbative treatment. Spin-orbit coupling is introduced through an effective Hamiltonian. These theoretical results are used to discuss the experimental results of Breckenridge, Jouvet and Soep for the reaction Hg( 3P 1) + H 2 ? HgH( 2? +)+H.

Bernier, Anne; Millié, Philippe

1987-02-01

294

Re-examining Potential for Geothermal Energy in United States  

NASA Astrophysics Data System (ADS)

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.

Showstack, Randy

295

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

NASA Astrophysics Data System (ADS)

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

Sarkar, Abhishek; Schlüter, Jörg

2013-11-01

296

Converted Phase Elastic Migration Velocity Analysis  

E-print Network

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 ...

Shabelansky, Andrey Hanan

2013-01-01

297

Kappa distribution in the presence of a potential energy  

NASA Astrophysics Data System (ADS)

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

Livadiotis, George

2015-02-01

298

Investigating Energy-Saving Potentials in the Cloud  

PubMed Central

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

Lee, Da-Sheng

2014-01-01

299

Elastic differential cross sections for C4F6 isomers in the 1.5-200 eV energy electron impact: Similarities with six fluorine containing molecules and evidence of F-atom like scattering  

NASA Astrophysics Data System (ADS)

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.

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

300

Elastic differential cross sections for C?F? isomers in the 1.5-200 eV energy electron impact: similarities with six fluorine containing molecules and evidence of F-atom like scattering.  

PubMed

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

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

301

Elastic scattering of electrons by gadolinium and barium atoms  

NASA Astrophysics Data System (ADS)

Total and differential cross-sections for elastic scattering of electrons from gadolinium and barium atoms in a wide energy range were calculated. In the low- and intermediate-energy regions, the phase theory of elastic scattering was used. At low incident energies (<10 eV), an additional polarization potential was introduced. At high incident energies, the Born approximation (keV range) and the Rutherford formula (MeV range) were applied. Our results are in rather good agreement with experimental data of Romanyuk et al. (Pis'ma Zh. Eksp. Teor. Fiz. 32 (1980) 472) for elastic scattering of very-low-energy electrons from barium atoms which confirm its reliability. This agreement is important because these experimental results are in serious disagreement with theoretical calculations of Szmytkowski and Sienkiewicz (Phys. Rev. A 50 (1994) 4007).

Miloshevsky, G. V.; Tolkach, V. I.; Rozin, S.; Shani, G.

2000-08-01

302

Communication: Separable potential energy surfaces from multiplicative artificial neural networks  

NASA Astrophysics Data System (ADS)

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

Koch, Werner; Zhang, Dong H.

2014-07-01

303

Framework for State-Level Renewable Energy Market Potential Studies  

SciTech Connect

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

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

2010-01-01

304

Communication: Separable potential energy surfaces from multiplicative artificial neural networks  

SciTech Connect

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

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

2014-07-14

305

Geospatial Analysis of Renewable Energy Technical Potential on Tribal Lands  

SciTech Connect

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.

Doris, E.; Lopez, A.; Beckley, D.

2013-02-01

306

U.S. Carbon offset potential using biomass energy systems  

Microsoft Academic Search

A previous analysis had assumed that about 20% of 1990 U.S. C emissions could be avoided by the substitution of biomass energy technologies for fossil energy technologies at some point in the future. Short-rotation woody crop (SRWC) plantations were found to be the dedicated feedstock supply system (DFSS) offering the greatest C emission reduction potential. High efficiency biomass to electricity

L. L. Wright; E. E. Hughes

1993-01-01

307

The potential for energy efficiency in electric end use technologies  

Microsoft Academic Search

The authors summarize a recent study conducted by the Electric Power research Institute (EPRI) that contains estimates of potential energy savings that will result if the most efficient electricity technologies readily available immediately attain complete market saturation in the year 2000. They first define and contrast various efficiency scenarios and then summarize the energy savings forecast associated with demand-side management

G. Wikler; A. Faruqui; C. W. Gellings; K. Seiden

1993-01-01

308

Using peat for energy: Potential environmental restraints. Overview  

Microsoft Academic Search

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

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

1981-01-01

309

Overview - using peat for energy: potential environmental constraints  

Microsoft Academic Search

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

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

1981-01-01

310

Bagasse energy cogeneration potential in the Zimbabwean sugar industry  

Microsoft Academic Search

The cogeneration of steam and electricity has become the norm in the sugarcane industry worldwide. This process has been taken further to a stage where sugar companies can export a substantial amount of energy to the grid. Mauritius and Reunion Islands have implemented state of the art technology in bagasse energy cogeneration. It is on this basis that the potential

Charles Mbohwa

2003-01-01

311

The potential role of renewable energy in Moldova  

Microsoft Academic Search

The European Union (EU) is developing an increasingly close relationship with Moldova, going beyond cooperation, to gradual economic integration and a deepening of political cooperation. This fact indicates that eventually the adoption of EU legislation in the energy sector is a necessity. Therefore, the provision of a clear picture of the country’s renewable energy potential is considered essential, bearing in

Charikleia Karakosta; Stamatia Dimopoulou; Haris Doukas; John Psarras

2011-01-01

312

Brazilian waste potential: energy, environmental, social and economic benefits  

Microsoft Academic Search

The potential energy that could be produced from solid wastes in Brazil tops 50TWh. Equivalent to some 17% of the nation's total power consumption at costs that are competitive with more traditional options, this would also reduce greenhouse gases emissions. Moreover, managing wastes for energy generation purposes could well open up thousands of jobs for unskilled workers. Related to power

Luciano Basto Oliveira; Luiz Pinguelli Rosa

2003-01-01

313

Exact Description of Rotational Waves in an Elastic Solid  

E-print Network

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.

R. A. Close

2010-12-03

314

Dark energy exponential potential models as curvature quintessence  

E-print Network

It has been recently shown that, under some general conditions, it is always possible to find a fourth order gravity theory capable of reproducing the same dynamics of a given dark energy model. Here, we discuss this approach for a dark energy model with a scalar field evolving under the action of an exponential potential. In absence of matter, such a potential can be recovered from a fourth order theory via a conformal transformation. Including the matter term, the function f(R) entering the generalized gravity Lagrangian can be reconstructed according to the dark energy model.

S. Capozziello; V. F. Cardone; E. Piedipalumbo; C. Rubano

2005-07-19

315

Angular and lateral distributions from small angle multiple scattering including elastic and inelastic energy loss effects based on the Valdes and Arista model  

NASA Astrophysics Data System (ADS)

The aims of this work are to compare and to include two energy loss effects in multiple scattering caused by elastic and inelastic collisions in angular and lateral distributions based on Valdes and Arista (VA) theory. VA developed small angle multiple scattering theory including energy loss effects based on the Sigmund and Winterbon model for the first time. However, the energy loss effects on lateral distributions have not yet been estimated. In the VA model, target thickness and energy loss are independently treated. In this study, those effects are successfully introduced on the basis of the VA model. We considered the lateral spread and angular distribution separately and included the nuclear and electronic energy loss effects as a function of target thickness. Our results indicate that discrepancies occur between the two distributions, including nuclear and electronic stopping for several target thickness. Moreover, we constructed a multiple scattering model that includes both elastic and inelastic energy losses.

Ikegami, Seiji

2013-12-01

316

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

E-print Network

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.

I. Casinos

2008-05-22

317

Renewable energy potential in Bulgaria - Some computer simulations results  

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

318

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

PubMed Central

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

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

2015-01-01

319

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

NASA Astrophysics Data System (ADS)

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

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

1999-01-01

320

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

PubMed

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

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

2015-01-01

321

Atomic modeling and prediction of the structure, energy characteristics of point defects, and thermodynamic and elastic properties of the simple and complex beryllium oxides  

Microsoft Academic Search

A set of partially covalent interatomic potentials has been developed with the aim of reproducing the experimentally known\\u000a crystal structures and predicting the unknown crystal structures and the thermodynamic and elastic properties of bromellite\\u000a BeO, chrysoberyl BeAl2O4, and its isostructural analogs BeCr2O4 and BeFe2O4. The calculated structural, elastic, and thermodynamic properties of these minerals are in good agreement with the

N. N. Eremin; N. A. Gromalova; V. S. Urusov

2009-01-01

322

Optimizing potential energy functions for maximal intrinsic hyperpolarizability  

SciTech Connect

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

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

2007-11-15

323

The metabolic energy cost of action potential velocity  

NASA Astrophysics Data System (ADS)

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

Crotty, Patrick; Sangrey, Thomas; Levy, William

2006-03-01

324

Potential for energy conservation in the glass industry  

SciTech Connect

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.

Garrett-Price, B.A.; Fassbender, A.G.; Bruno, G.A.

1986-06-01

325

Variational formulation of a simplified strain gradient elasticity theory and its application to a pressurized thick-walled cylinder problem  

Microsoft Academic Search

A detailed variational formulation is provided for a simplified strain gradient elasticity theory by using the principle of minimum total potential energy. This leads to the simultaneous determination of the equilibrium equations and the complete boundary conditions of the theory for the first time. To supplement the stress-based formulation, the coordinate-invariant displacement form of the simplified strain gradient elasticity theory

X.-L. Gao; S. K. Park

2007-01-01

326

Global Onshore Wind Energy Potential and Its Uncertainties  

NASA Astrophysics Data System (ADS)

Wind power, a clean and renewable energy resource, can play an important role in providing energy and reducing greenhouse gas emissions. Yet there are substantial and important uncertainties about the potential costs and supplies of wind that influence our ability to understand today the strategic role of wind power in the future. A detailed global assessment of onshore wind energy potential and its uncertainties will help decision-makers develop policies and strategies to meet energy and environmental goals. In this study, we assess the technical and economic potential of onshore wind energy and its spatial distribution using reanalysis wind speed data from the National Centers for Environmental Modeling (Figure 1). The study focuses in particular in exploring a range of uncertainties that impact the economic potential of wind power by constructing quantitative scenarios for eight key physical and economic parameters. We present quantification of the impact of uncertainties in these parameters, focusing on areas relevant to geoscience research (Figure 2). The amount of economic potential of wind energy depends strongly on several uncertain parameters such as wind speed, turbine cost, and land-suitability. The distribution of wind speed at fine temporal and spatial scales is a key parameter, but is not well quantified in many regions of the world. Reanalysis datasets with more accurate wind fields are a first step, along with computationally tractable downscaling methodologies. Another key assumption is land-suitability, which is the fraction of a particular land-cover type assumed to be available for wind farm development. There is currently little scientific basis for land-suitability assumptions. While some of the data needed for progress in these areas is readily available, such as high-resolution land-cover and terrain data, further advances are likely to require new methodologies and inter-disciplinary collaboration. We outline a number of areas where further research is needed to construct improved estimates of global wind energy potential.

Zhou, Y.; Clarke, L.; Luckow, P.; Smith, S.

2011-12-01

327

Relativistic Elasticity  

E-print Network

Relativistic elasticity on an arbitrary spacetime is formulated as a Lagrangian field theory which is covariant under spacetime diffeomorphisms. This theory is the relativistic version of classical elasticity in the hyperelastic, materially frame-indifferent case and, on Minkowski space, reduces to the latter in the non-relativistic limit . The field equations are cast into a first -- order symmetric hyperbolic system. As a consequence one obtains local--in--time existence and uniqueness theorems under various circumstances.

Robert Beig; Bernd G. Schmidt

2003-04-28

328

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

Microsoft Academic Search

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

Lachlan J. Smith; Nicola L. Fazzalari

2009-01-01

329

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

PubMed

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

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

2012-04-01

330

Solar energy in California industry - Applications, characteristics and potential  

NASA Technical Reports Server (NTRS)

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.

Barbieri, R. H.; Pivirotto, D. S.

1978-01-01

331

Saturation wind power potential and its implications for wind energy.  

PubMed

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

Jacobson, Mark Z; Archer, Cristina L

2012-09-25

332

Saturation wind power potential and its implications for wind energy  

PubMed Central

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

Jacobson, Mark Z.; Archer, Cristina L.

2012-01-01

333

Matrix Pseudospectral Method for Elastic Tides Modeling of Planetary Bodies  

E-print Network

of the gravitational potential of prestressed elastic bodies caused by the tidal forces are described by means)elastic selfgravitating body to external or internal forces (tides, postglacial rebound, free oscillations) have a long of gravitational potential in a prestressed selfgravitating elastic Matrix Pseudospectral Method for Elastic Tides

Matyska, Ctirad

334

Superconductivity, the Structure Scale of the Universe, Tenth Edition (Elastic Resonant Symmetric Medium by Self-Energy)  

E-print Network

A theoretical framework supported by literature reported experimental evidence (Homes, Harshman along with Voyager, Hubble and EGRET space platforms and others) is presented which indicates that superconductivity is a self energy phenomenon and congruent with the concept of the Charge Conjugation, Parity Change and Time Reversal (CPT) theorem. A resonant symmetric structure is proposed as an extension of Bardeen Cooper and Schrieffer (BCS) theory, which suspends Lorentz transforms at superluminal velocities in the context of the de Broglie hypothesis. A momentum and energy conserving (elastic) CPT resonant structural lattice scalable over 15 orders of magnitude from nuclear to universe dimensions and associated superconducting theory is postulated whereby nuclear (quark) weak and strong forces, electromagnetic and gravitational forces are mediated by a particle of resonant velocity transformed mass (mt) (110.123 x electron mass or 56 Mev/c2), The universe mass and density are based on an isotropic homogeneous media filling the vacuum of and could be considered a candidate for dark matter/energy. The model predicts a deceleration value consistent with observed Pioneer 10 and 11 deep space translational and rotational deceleration and consistent with the notion that, An object moving through momentum space will slow down.

Richard D. Saam

2007-01-09

335

Cost-Energy Dynamics of Thermal Insulation: Potential Energy Savings and Policy Recommendations  

E-print Network

the extra cost and extra energy saving. Due to higher costs of energy at present and in the foreseeable future, good opportunities exist to retrofit existing thermal envelopes with extra insulation. Potential costs and savings in the residential, commercial...

Phung, D. L.; Plaza, H.

1980-01-01

336

A hierarchy of potential energy surfaces constructed from energies and energy derivatives calculated on grids  

NASA Astrophysics Data System (ADS)

In this work we develop and test a methodology for the generation of Born-Oppenheimer potential energy surfaces (PES) for use in vibrational structure calculations. The method relies on the widely used restricted-mode-coupling expansion of the fully coupled potential surface where only up to n or less vibrational coordinates are coupled in the potential. Low-order derivatives of the energy are then used to extrapolate the higher mode-coupling potential terms; derivative information is thus used in a convenient way for the evaluation of higher mode couplings avoiding their explicit calculation on multidimensional grids. The formulation, which is a variant of the popular modified Shepard interpolation, is general for any extrapolation of (n +p)-mode-coupling terms from n-mode couplings and can be applied to the energy or any other molecular property surface for which derivative information is available. The method depends only on analytical parameter-free weight functions that satisfy important limiting conditions and control the contribution from each direction of extrapolation. The procedure has been applied on a representative set of 13 molecules, and its accuracy has been tested using only gradients and using both gradients and Hessians. The results provide evidence for the importance of higher mode couplings and illustrate the cost efficiency of the proposed approach.

Matito, Eduard; Toffoli, Daniele; Christiansen, Ove

2009-04-01

337

Distribution of vibrational potential energy in molecular systems  

NASA Astrophysics Data System (ADS)

It is shown that for a collection of n classical harmonic oscillators, the long-time distribution of potential energies P is approximated by sinm(?P) for n?4, where m=(8n/?2-1/?2) and P is scaled to lie between 0 and 1. As n??, the distribution tends to a ?-function centered about P=0.5. When coupling is present between the oscillators, the effective value of m is reduced, so that the breadth of the potential energy distribution reflects the degree of randomization in the system.

Pritchard, Huw O.; Raj Vatsya, S.; Shen, DeLin

1999-05-01

338

Investigating fundamental antiproton-nucleon interactions by means of p -nucleus elastic scattering  

SciTech Connect

Antinucleon-nucleus elastic scattering is addressed from the point of view of the off-shell properties of the two-body {ital {bar p}}-nucleon system. The energy dependence of the interaction is studied. Comparison with {ital {bar p}}-{sup 12}C elastic-scattering data at 50 MeV is satisfactory but shows very little sensitivity to the underlying potential. Scattering data at lower projectile energies should improve the situation.

Gibbs, W.R. (Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA)); Kaufmann, W.B. (Department of Physics, Arizona State University, Tempe, Arizona 85287 (USA)); Loiseau, B.; Lacombe, M.; Vinh Mau, R. (Division de Physique Theorique, Institut de Physique Nucleaire, 91406 Orsay CEDEX (France) Laboratoire de Physique Theorique des Particules Elementaires, Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris CEDEX 05, (France))

1990-06-01

339

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

Microsoft Academic Search

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

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

2000-01-01

340

Benchmarking van der Waals density functionals with experimental data: potential-energy curves for H2 molecules on Cu(111), (100) and (110) surfaces  

NASA Astrophysics Data System (ADS)

Detailed physisorption data from experiment for the H2 molecule on low-index Cu surfaces challenge theory. Recently, density functional theory (DFT) has been developed to account for nonlocal correlation effects, including van der Waals (dispersion) forces. We show that the functional vdW-DF2 gives a potential-energy curve, potential-well energy levels and difference in lateral corrugation promisingly close to the results obtained by resonant elastic backscattering-diffraction experiments. The backscattering barrier is sensitive to the choice of exchange functional approximation. Further, the DFT-D3 and TS-vdW corrections to traditional DFT formulations are also benchmarked, and deviations are analyzed.

Lee, Kyuho; Berland, Kristian; Yoon, Mina; Andersson, Stig; Schröder, Elsebeth; Hyldgaard, Per; Lundqvist, Bengt I.

2012-10-01

341

Ab initio potential energy surface for the HCl dimer  

Microsoft Academic Search

An intermolecular potential energy surface for the dimer of hydrogen chloride in the ground state is calculated at the levels of the second-order (MP2) and fourth-order (MP4) Mo&slash;ller–Plesset approximations using a large basis set containing bond functions. The surface is characterized by the minimum energy pathway through two equivalent hydrogen-bonded structures. The hydrogen-bonded equilibrium geometry has the centers of mass

Fu-Ming Tao; William Klemperer

1995-01-01

342

Reference pressure changes and available potential energy in isobaric coordinates  

NASA Technical Reports Server (NTRS)

A formulation of the available potential energy (APE) equation in isobaric coordinates which alleviates the need for computing temporal derivatives of reference pressure and describes how work done relates to changes in the APE of a limited region is presented. The APE budget equation possesses terms analogous to those in Johnson's (1970) isentropic version. It is shown that APE changes result from either mechanical work inside the domain or an exchange of energy via boundary processes with the surrounding environment.

Robertson, F. R.

1985-01-01

343

Potential structural material problems in a hydrogen energy system  

NASA Technical Reports Server (NTRS)

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.

Gray, H. R.; Nelson, H. G.; Johnson, R. E.; Mcpherson, B.; Howard, F. S.; Swisher, J. H.

1975-01-01

344

On first strain-gradient theories in linear elasticity  

Microsoft Academic Search

This paper contains a study of the linear theory of elasticity in which the potential energy-density depends on the gradient of the strain in addition to the strain. In the first part of the paper, three forms of the theory are compared and the relations connecting the stresses in the three forms and the boundary conditions in the three forms

R. D. MINDLIN; N. N. ESHEL

1968-01-01

345

Fossil energy savings potential of sugar cane bio-energy systems  

Microsoft Academic Search

One important rationale for bio-energy systems is their potential to save fossil energy. Converting a conventional sugar mill into a bio-energy process plant would contribute to fossil energy savings via the extraction of renewable electricity and ethanol substituting for fossil electricity and gasoline, respectively. This paper takes a closer look at the Thai sugar industry and examines two practical approaches

Thu Lan T. Nguyen; John E. Hermansen; Masayuki Sagisaka

2009-01-01

346

Off-Shell NN Potential and Triton Binding Energy  

E-print Network

The NONLOCAL Bonn-B potential predicts 8.0 MeV binding energy for the triton (in a charge-dependent 34-channel Faddeev calculation) which is about 0.4 MeV more than the predictions by LOCAL NN potentials. We pin down origin and size of the nonlocality in the Bonn potential, in analytic and numeric form. The nonlocality is due to the use of the correct off-shell Feynman amplitude of one-boson-exchange avoiding the commonly used on-shell approximations which yield the local potentials. We also illustrate how this off-shell behavior leads to more binding energy. We emphasize that the increased binding energy is not due to on-shell differences (differences in the fit of the NN data or phase shifts). In particular, the Bonn-B potential reproduces accurately the $\\epsilon_1$ mixing parameter up to 350 MeV as determined in the recent Nijmegen multi-energy NN phase-shift analysis. Adding the relativistic effect from the relativistic nucleon propagators in the Faddeev equations, brings the Bonn-B result up to 8.2 MeV triton binding. This leaves a difference of only 0.3 MeV to experiment, which may possibly be explained by refinements in the treatment of relativity and the inclusion of other nonlocalities (e.~g., quark-gluon exchange at short range). Thus, it is conceivable that a realistic NN potential which describes the NN data up to 300 MeV correctly may explain the triton binding energy without recourse to 3-N forces; relativity would play a major role for this result.

Y. Song; R. Machleidt

1994-03-31

347

Evidence of Cholesterol Accumulated in High Curvature Regions: Implication ot the Curvature Elastic Energy for Lipid Mixtures  

SciTech Connect

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.

Wang,W.; Yang, L.; Huang, H.

2007-01-01

348

Magnetically responsive elastic microspheres  

NASA Astrophysics Data System (ADS)

We report the design, fabrication, and characterization of magnetically responsive elastic microspheres consisting of polydimethylsioxane (PDMS) and magnetic nano-/microparticles. The microspheres can have either core-shell or solid structure, fabricated by using a microfluidic technique. The mechanical characteristics are determined with a modified electronic balance, and the results show that the microspheres exhibit magnetostrictive effect. Such microspheres can in addition behave as a smart material controllable through an external magnetic field. Owing to the transparency, biocompatibility and nontoxicity of PDMS, the magnetically responsive elastic microspheres may have potential applications in drug delivery, biosensing, bioseparation, and medical diagnosis.

Peng, Suili; Zhang, Mengying; Niu, Xize; Wen, Weijia; Sheng, Ping; Liu, Zhengyou; Shi, Jing

2008-01-01

349

Inverse scattering with fixed energy for dilation-analytic potentials  

NASA Astrophysics Data System (ADS)

For N-body Schrödinger operators P = -Dgr + sum1lesienergy lgr > 0 uniquely determines all Vij in the class of dilation-analytic Schwartz potentials. The same question for two-body Schrödinger operators remains open.

Vasy, András; Wang, Xue-Ping

2004-08-01

350

Potential energy surfaces and spectra of superheavy elements  

Microsoft Academic Search

The potential energy surfaces of some superheavy nuclei are determined, using a mapping from the microscopic shell model space to a geometrical model. The content of the shell model space is determined through the knowledge of the absolute deformation and a single-particle spectrum as a function of deformation. Both have to be extracted from a microscopic model. We show that

P. O. Hess; Serban Misicu

2003-01-01

351

Unified Technical Concepts. Module 7: Potential and Kinetic Energy.  

ERIC Educational Resources Information Center

This concept module on potential and kinetic energy is one of thirteen modules that provide a flexible, laboratory-based physics instructional package designed to meet the specialized needs of students in two-year, postsecondary technical schools. Each of the thirteen concept modules discusses a single physics concept and how it is applied to each…

Technical Education Research Center, Waco, TX.

352

Energy and water potential of the Southeastern Anatolia Project (GAP)  

Microsoft Academic Search

This article gives an overview of energy and water potential of the Southeastern Anatolia Project (GAP) in Turkey. This integrated socioeconomic development project is one of the largest of its kind in the world. The GAP region is rich in water and soil resources. The Euphrates and Tigris Rivers represent over 28% of the nation's water supply by rivers, and

Kamil Kaygusuz

1999-01-01

353

Potentials of wind energy development for water pumping in Jordan  

Microsoft Academic Search

The potential of the development of water pumping using wind energy in Jordan was studied. Underground water can be pumped using wind power. Based on available wind data eleven wind sites were considered. The results show that these sites can be divided, in terms of the annual amount of pumped water, into three categories. One is considered “favorable”, which includes

Mousa S. Mohsen; Bilal A. Akash

1998-01-01

354

Low energy chiral two pion exchange potential with statistical uncertainties  

E-print Network

We present a new phenomenological Nucleon-Nucleon chiral potential fitted to 925 pp and 1743 np scattering data 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/\

R. Navarro Perez; J. E. Amaro; E. Ruiz Arriola

2014-11-05

355

Methods for finding transition states on reduced potential energy surfaces  

Microsoft Academic Search

Three new algorithms are presented for determining transition state (TS) structures on the reduced potential energy surface, that is, for problems in which a few important degrees of freedom can be isolated. All three methods use constrained optimization to rapidly find the TS without an initial Hessian evaluation. The algorithms highlight how efficiently the TS can be located on a

Steven K. Burger; Paul W. Ayers

2010-01-01

356

Renewable energy in Kenya: Resource potential and status of exploitation  

Microsoft Academic Search

This paper presents an assessment of renewable energy resource potential and the current status of exploitation in Kenya. As an importer of petroleum fuels, Kenya spends a substantial amount of foreign reserves to import oil. The oil import bill in 2008 consumed 55% of the country's foreign exchange earnings from exports. On the other hand, there is a high dependence

J. K. Kiplagat; R. Z. Wang; T. X. Li

2011-01-01

357

Potential of solar energy development for water pumping in Jordan  

Microsoft Academic Search

The potential of solar energy development for water pumping in Jordan was studied. For this purpose, 10 sites were selected based on the available solar radiation data. According to the annual amount of water output, the selected sites can be divided into three different categories: the first one, which includes Taffieleh, Queira, H-4, and H-5, is considered to be “adequate”

Eyad S. Hrayshat; Mohammed S. Al-Soud

2004-01-01

358

Analysis of energy dissipation and deposition in elastic bodies impacting at hypervelocities  

NASA Technical Reports Server (NTRS)

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.

Medina, David F.; Allahdadi, Firooz A.

1992-01-01

359

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

NASA Astrophysics Data System (ADS)

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

Alicandro, Roberto; Cicalese, Marco; Gloria, Antoine

2011-06-01

360

Hydro-elastic response reduction system of a very large floating structure with wave energy absorption devices  

Microsoft Academic Search

A very large floating structure has hydro-elastic responses that are an elastic deformation and a slowly varying drift motion. Generally, a breakwater is established to reduce the responses. However, it is very difficult to construct it from a technical point of view and costs rise when the water depth increases. Therefore, it is necessary to develop the response reduction system

H. Maeda; Y. Washio; H. Osawa; Chang-Kyu Rheem; T. Ikoma; Y. Onishi; M. Arita

2000-01-01

361

Noise activated dissociation of soft elastic contacts  

E-print Network

Adhesive forces are capable of deforming a soft elastic object when it comes in contact with a flat rigid substrate. The contact is in stable equilibrium if the total energy of the system arising from the elastic and surface forces exhibits a minimum at a zero or at a slightly negative load. However, as the system is continually unloaded, the energy barrier decreases and it eventually disappears, thus leading to a ballistic separation of the contact. While this type of contact splitting has received wide recognition, what has not been much appreciated with these types of soft adhesion problems is that rupture of a contact can also occur at any finite sub critical load in the presence of a noise. The soft contact problems are unique in that the noise can be a-thermal, whereas the metastable and stable states of the thermodynamic potential can arise from the competition of the elastic and the inter-facial energies of the system. Analysis based on activated rate theory and simulations based on stochastic dynamics show that the contact rupture dynamics is amenable to a force and noise induced escape of a particle from a potential well that is generic to various types of colloidal and macromolecular processes. These ideas are useful in understanding the results of a recent experiment involving the noise activated rolling dynamics of a rigid sphere on a surface, where it is pinned by soft micro-fibrils.

M. K. Chaudhury; P. S. Goohpattader

2014-02-03

362

Collective potential energy surfaces of light mass Kr isotopes  

NASA Astrophysics Data System (ADS)

Collective potential energy surface calculations have been performed for 74-80Kr nuclei in the framework of the Gneuss and Greiner model. The collective Hamiltonian is diagonalized in the basis of the five-dimensional quadrupole oscillator. Our calculations suggest that the 78,80Kr nuclei are ? unstable with a triaxial minimum at ?~=40°. The 74,76Kr nuclei have two axially symmetric minima with the 0+1 ground state being located mainly in the deformed minimum, whereas the first excited 0+2 state is located in the spherical minimum. The calculations also indicate that the ground state wave function for 74Kr is spread over both the minima. [NUCLEAR STRUCTURE 74,76,78,80Kr: Calculated potential energy surfaces; compared with experimental energy levels and B(E2) values.

Seiwert, M.; Ramayya, A. V.; Maruhn, J.

1984-01-01

363

Potentials and policy implications of energy and material efficiency improvement  

SciTech Connect

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.

Worrell, Ernst; Levine, Mark; Price, Lynn; Martin, Nathan; van den Broek, Richard; Block, Kornelis

1997-01-01

364

Elastic transfer in the sup 11 B+ sup 12 C system in the c. m. energy range 5--40 MeV  

SciTech Connect

Measurements of angular distributions for elastic scattering in the {sup 11}B + {sup 12}C system were performed in the energy range from 15 to 40 MeV c.m. in {congruent}2.5 MeV steps in broad angular regions up to about 170{sup {degree}} c.m. The optical-model parameters were determined from the analysis of the cross section at forward angles. The rise of cross section in the backward angles was explained as direct elastic transfer. From the distorted-wave Born approximation analysis, the values of proton spectroscopic factor in {sup 12}C were found. They exhibit a strong energy dependence in the energy region between 5 and 40 MeV c.m.

Albergo, S.; Costa, S.; Potenza, R.; Romanski, J.; Tuve, C. (Dipartimento di Fisica, Universita di Catania, Catania (Italy) Istituto Nazionale di Fisica Nucleare, Sezione di Catania, I-95129 Catania (Italy)); Jarczyk, L.; Kamys, B.; Magiera, A.; Strzalkowski, A. (Institute of Physics, Jagellonian University, PL-30059 Cracow (Poland)); Barna, R.; D'Amico, V.; De Pasquale, D.; Mannino, G. (Istituto di Fisica, Universita di Messina, Messina (Italy) Istituto Nazionale di Fisica Nucleare, Messina (Italy) Sezione di Catania, Gruppo distaccato di Messina, I-98166 Messina (Italy))

1991-06-01

365

Polarization parameters A sub 000 n and A sub 00 nn in elastic proton-proton scattering in the energy region 690--890 MeV  

SciTech Connect

An experiment has been performed to measure the asymmetry {ital A}{sub 000{ital n}} and the polarization correlation coefficient {ital A}{sub 00{ital nn}} in elastic proton-proton scattering at energies 690, 850, and 890 MeV. A comparison of the data obtained with the predictions of the phase-shift analysis of Hoshizaki {ital et} {ital al}. is presented. The ratio of the contributions of triplet and singlet interactions to the {ital pp}-scattering elastic cross section at angle 90{degree} is obtained at energy 690 MeV. Preliminary data are given on the behavior of the {sup 1}{ital D}{sub 2} and {sup 3}{ital F}{sub 3} phase shifts obtained in a phase-shift analysis at energies 850 and 890 MeV carried out with inclusion of the data of the present work.

Vovchenko, V.G.; Efimovykh, V.A.; Zhdanov, A.A.; Kazarinov, Y.M.; Kiselev, Y.F.; Kovalev, A.I.; Polyakov, V.V.; Popov, V.E.; Prokof'ev, A.N.; Trautman, V.Y.; and others

1989-03-01

366

Electron-Hydrogen Elastic Scattering  

NASA Technical Reports Server (NTRS)

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.

Bhatia, A. K.

2004-01-01

367

Energy-Dependence of Elastic Alpha-Particle Scattering - Microscopic Model  

E-print Network

(1962). PHYSIC AL RE VIE W C VO LUME 6, NUMB E R 4 OCTOBER 1972 Study of ( He, t) Reactions at 70 MeV to Isobaric Analog States of Cr, Ni, and Zr~ R. A. Hinrichs and D. L. Show Cyclotron Laboratory, Michigan State University, East Lansing, Michigan... on the energy dependence of the charge- exchange interaction. II. EXPERIMENTAL PROCEDURE AND RESULTS The reactions ~Cr, "Ni, "Zr('He, t) were studied at a bombarding energy of 70 MeV using 'He ions accelerated in the Michigan State Univer- sity sector...

Lerner, G. M.; Rutledge, L. L.; Hiebert, John C.; Bernstein, A. M.

1972-01-01

368

U.S. Building-Sector Energy Efficiency Potential  

SciTech Connect

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).

Brown, Rich; Borgeson, Sam; Koomey, Jon; Biermayer, Peter

2008-09-30

369

Potential energy profile of colloidal nanoparticles in optical confinement.  

PubMed

An optical bottle method is developed to determine the potential-energy profile of colloidal Rayleigh nanoparticles in an optical trap. The three-dimensional distribution of fluorescent particles in the trap is measured by laser scanning confocal fluorescence microscopy. At sufficiently low concentrations at which interactions between the particles are negligible, the single-particle trapping potential-energy profile is determined from the equilibrium number-density profile by use of the Boltzmann distribution. Fluorescence imaging as well as calculations based on a discrete dipole approximation show that effects due to scattering forces are negligible for polystyrene particles of size less than 10% of the wavelength of the trapping laser, thus justifying the assumption of conservative forces in the equilibrium potential-energy determinations. The new optical bottle method measures the entire two-dimensional trapping-potential profile for an individual nanoparticle without the restriction that only one particle be contained in the trap, thus obviating the need for high laser power. PMID:24321903

Fu, Jinxin; Zhan, Qiwen; Lim, Min Yao; Li, Zhiyuan; Ou-Yang, H Daniel

2013-10-15

370

DESIGN AND VALIDATION OF A HIGH ENERGY DENSITY ELASTIC ACCUMULATOR USING POLYURETHANE  

E-print Network

brake pads and a brake disk to slow a vehicle down. This method results in energy being wasted as heat.j.barth@vanderbilt.edu ABSTRACT Hydraulic accumulators (HAs) have been used successfully in regenerative braking systems application of these devices is regenerative braking. A conventional braking system uses friction between

Barth, Eric J.

371

Effects of bonding on the energy distribution of electrons scattered elastically at high momentum transfer  

SciTech Connect

High-resolution measurements of 40-keV electrons scattered over 44.3 deg. from evaporated carbon films are presented. The observed width of the energy distribution of electrons scattered from carbon is significantly larger than the experimental energy resolution, and its position is shifted to lower energy. Measurements were done for transmission and reflection geometries for thin films with thicknesses varying from 90 A ring to 1400 A ring . The observed peak shape is largely independent of the thickness and measurement geometry. The peak shape deviates from Gaussian in all cases, in a way consistent with theories that describe these processes beyond the impulse approximation. The energy shift of the carbon peak is measured by evaporating a small amount of Au on these films. Separation of the Au and C peak is somewhat smaller than calculated assuming scattering from free C and Au atoms, but independent of measurement geometry. Finally spectra were measured from highly oriented pyrolytic graphite (HOPG) films. Now different widths are observed in reflection geometry and transmission geometry. This is attributed to the anisotropy of the motion of the C atoms in HOPG. Also the Au-C separation is slightly orientation dependent for HOPG. All observations agree at least semiquantitatively with neutron Compton scattering results, a related scattering experiment that studies neutron-atom collisions at similar momentum transfers.

Vos, M.; Went, M. R. [Atomic and Molecular Physics Laboratories6, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia)

2006-11-15

372

Evaluation of global onshore wind energy potential and generation costs.  

PubMed

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

Zhou, Yuyu; Luckow, Patrick; Smith, Steven J; Clarke, Leon

2012-07-17

373

Potential for Materials and Energy RecoveryPotential for Materials and Energy Recovery the Municipal Solid Wastes (the Municipal Solid Wastes (MSWMSW) of Beograd) of Beograd  

E-print Network

Potential for Materials and Energy RecoveryPotential for Materials and Energy Recovery fromfrom%) and glass (15%). · Recovery of energy by anaerobic digestion: The natural organics in MSW react presence of oxygen) · Recovery of energy and some metals: Combusting all organic compounds in waste-to-energy

Columbia University

374

NVU dynamics. III. Simulating molecules at constant potential energy  

NASA Astrophysics Data System (ADS)

This is the final paper in a series that introduces geodesic molecular dynamics at constant potential energy. This dynamics is entitled NVU dynamics in analogy to standard energy-conserving Newtonian NVE dynamics. In the first two papers [T. S. Ingebrigtsen, S. Toxvaerd, O. J. Heilmann, T. B. Schrøder, and J. C. Dyre, J. Chem. Phys. 135, 104101 (2011), 10.1063/1.3623585; T. S. Ingebrigtsen, S. Toxvaerd, T. B. Schrøder, and J. C. Dyre, J. Chem. Phys. 135, 104102 (2011), 10.1063/1.3623586], a numerical algorithm for simulating geodesic motion of atomic systems was developed and tested against standard algorithms. The conclusion was that the NVU algorithm has the same desirable properties as the Verlet algorithm for Newtonian NVE dynamics, i.e., it is time-reversible and symplectic. Additionally, it was concluded that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit. In this paper, the NVU algorithm for atomic systems is extended to be able to simulate the geodesic motion of molecules at constant potential energy. We derive an algorithm for simulating rigid bonds and test this algorithm on three different systems: an asymmetric dumbbell model, Lewis-Wahnström o-terphenyl (OTP) and rigid SPC/E water. The rigid bonds introduce additional constraints beyond that of constant potential energy for atomic systems. The rigid-bond NVU algorithm conserves potential energy, bond lengths, and step length for indefinitely long runs. The quantities probed in simulations give results identical to those of Nosé-Hoover NVT dynamics. Since Nosé-Hoover NVT dynamics is known to give results equivalent to those of NVE dynamics, the latter results show that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit also for molecular systems.

Ingebrigtsen, Trond S.; Dyre, Jeppe C.

2012-12-01

375

NVU dynamics. III. Simulating molecules at constant potential energy.  

PubMed

This is the final paper in a series that introduces geodesic molecular dynamics at constant potential energy. This dynamics is entitled NVU dynamics in analogy to standard energy-conserving Newtonian NVE dynamics. In the first two papers [T. S. Ingebrigtsen, S. Toxvaerd, O. J. Heilmann, T. B. Schrøder, and J. C. Dyre, J. Chem. Phys. 135, 104101 (2011); T. S. Ingebrigtsen, S. Toxvaerd, T. B. Schrøder, and J. C. Dyre, ibid. 135, 104102 (2011)], a numerical algorithm for simulating geodesic motion of atomic systems was developed and tested against standard algorithms. The conclusion was that the NVU algorithm has the same desirable properties as the Verlet algorithm for Newtonian NVE dynamics, i.e., it is time-reversible and symplectic. Additionally, it was concluded that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit. In this paper, the NVU algorithm for atomic systems is extended to be able to simulate the geodesic motion of molecules at constant potential energy. We derive an algorithm for simulating rigid bonds and test this algorithm on three different systems: an asymmetric dumbbell model, Lewis-Wahnström o-terphenyl (OTP) and rigid SPC/E water. The rigid bonds introduce additional constraints beyond that of constant potential energy for atomic systems. The rigid-bond NVU algorithm conserves potential energy, bond lengths, and step length for indefinitely long runs. The quantities probed in simulations give results identical to those of Nosé-Hoover NVT dynamics. Since Nose?-Hoover NVT dynamics is known to give results equivalent to those of NVE dynamics, the latter results show that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit also for molecular systems. PMID:23277922

Ingebrigtsen, Trond S; Dyre, Jeppe C

2012-12-28

376

A global potential energy surface for ArH2  

NASA Technical Reports Server (NTRS)

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.

Schwenke, David W.; Walch, Stephen P.; Taylor, Peter R.

1992-01-01

377

An exploration of the ozone dimer potential energy surface  

SciTech Connect

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.

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

378

Search for dark energy potentials in quintessence theory  

E-print Network

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$....

Muromachi, Yusuke; Okada, Daiki; Hara, Tetsuya; Itoh, Yutaka

2015-01-01

379

Potential Energy of Heavy Nuclear System in Low-energy Fusion-fission Processes  

NASA Astrophysics Data System (ADS)

The problem of description of low-energy nuclear dynamics and derivation of multi-dimensional potential energy surface depending on several collective degrees of freedom is discussed. Multi-dimensional adiabatic potential is constructed basing on extended version of the two-center shell model. It has correct asymptotic value and height of the Coulomb barrier in the entrance channel (fusion) and appropriate behavior in the exit one, giving required mass and energy distributions of reaction products and fission fragments. Explicit time-dependence of the driving potential was introduced in order to take into account difference of diabatic and adiabatic regimes of motion of nuclear system at above-barrier energies and also difference of nuclear shapes in fusion and fission channels (neck formation). Derived driving potential is proposed to be used for unified analysis of the processes of deep-inelastic scattering, fusion and fission at low-energy collisions of heavy ions.

Karpov, A. V.; Zagrebaev, V. I.; Aritomo, Y.; Naumenko, M. A.; Greiner, W.

2007-05-01

380

Development of the Potential Energy Savings Estimation (PESE) Toolkit  

E-print Network

DEVELOPMENT OF THE POTENTIAL ENERGY SAVINGS ESTIMATION (PESE) TOOLKIT Jingjing Liu Graduate Research Assistant Juan-Carlos Baltazar, Ph.D. Associate Research Engineer David E. Claridge, Ph.D., P.E. Professor/ Director Energy Systems... FALSE Zone T reset point during unoccupied hours Atot 19,800 ft 2 Te_unocp ?F Ae 7,800 ft 2 ##### of Atot Ti_unocp ?F Ai 12,000 ft 2 ##### of Atot VTD 27,545 cfm Ve cfm Ocpe 20 pep Vi cfm Ocpi 20 pep TCL (setpoint 1) 64 ?F @ TOA1= 25 ?F Ave...

Liu, J.; Baltazar, J. C.; Claridge, D. E.

381

Geothermal Energy Potential of Turkey: Inferred from the Aeromagnetic data  

NASA Astrophysics Data System (ADS)

Geothermal energy potential of Turkey is well known. There are lots of hot springs with over 30° C water temperatures. However, the significance of these geothermal energy potential of Turkey is not adequately understood. We believe that the main reason for this; is the lack of exploration methods and tools in a wide area as large as Turkey. We exploited a well known physical property of rocks to estimate the geothermal energy potential. Physically, substances lose their magnetization above a temperature known as the Curie that is the 580° C for magnetite. Properties of the Curie temperature have been exploited to observe the bottom depth of the magnetization. That is the depth where the heat reaches to 580° C. In another word, there is no magnetization below this depth. In normal crust this depth is about 22-24 km. Thus, investigation of the bottom depth of magnetization by using aeromagnetic anomalies can lead to information that if there are any anomalous regions well above the normal crust. The aeromagnetic anomalies of whole of Turkey were surveyed by the Mineral Research and Exploration (MTA) of Turkey. The survey was completed during late 1980's. Five kilometers grid data were available and used for regional exploration purposes. Exploration of the geothermal energy potential of Turkey was done from west to east in the similar way to search for shallow high temperature regions. These are from west to east; i.) Western Turkey: Two major shallow depth regions were determined at the west of Kutahya and the north-east of Denizli. The Curie Point Depths (CPDs) were calculated as about 7 km and about 9 km in Kutahya and Denizli, respectively. Also, high heat flow values and crustal thinning (about 32 km from gravity anomalies of western Turkey) were calculated for western Turkey. ii.) Central Turkey: A CPD depth of 8 km was calculated. This gives us a temperature gradient of 0.073° C/m. Geothermal energy potential was studied using water chemistry and isotopic research borehole called SHK-1. Thermal gradient is about 0.75° C/m (Borehole depth is 1677 m). These independent researches are indicative of high geothermal potential of the region. iii.) Eastern Turkey: The CPD was calculated as the same way as in the west and centre. It was suggested that the individual sources of volcanic regions exhibit geothermal energy source. As a conclusion; Turkey has several important high geothermal rich areas. These thermal regions can also be well correlated with the hot spring areas of the country. Temperatures obtained from the available wells provide additional contribution to understand the geothermal potential. In future, these potential high thermal regions should be explored in detail to utilize the energy potential before hydrocarbon sources becoming scarce.

Ates, Abdullah; Bilim, Funda; Buyuksarac, Aydin; Bektas, Ozcan

2010-05-01

382

Free Energy Generalization of the Peierls Potential in Iron  

NASA Astrophysics Data System (ADS)

In body-centered-cubic (bcc) crystals, 1/2?111? screw dislocations exhibit high intrinsic lattice friction as a consequence of their nonplanar core structure, which results in a periodic energy landscape known as the Peierls potential UP. The main features determining plastic flow, including its stress and temperature dependences, can be derived directly from this potential, hence its importance. In this Letter, we use thermodynamic integration to provide a full thermodynamic extension of UP for bcc Fe. We compute the Peierls free energy path as a function of stress and temperature and show that the critical stress vanishes at 700 K, supplying the qualitative elements that explain plastic behavior in the athermal limit.

Gilbert, M. R.; Schuck, P.; Sadigh, B.; Marian, J.

2013-08-01

383

Accurate global potential energy surface for the H + OH+ collision  

NASA Astrophysics Data System (ADS)

We mapped the global three-dimensional potential energy surface (3D-PES) of the water cation at the MRCI/aug-cc-pV5Z including the basis set superposition (BSSE) correction. This PES covers the molecular region and the long ranges close to the H + OH+(X3?-), the O + H2+(X2?g+), and the hydrogen exchange channels. The quality of the PES is checked after comparison to previous experimental and theoretical results of the spectroscopic constants of H2O+(tilde X2B1) and of the diatomic fragments, the vibronic spectrum, the dissociation energy, and the barrier to linearity for H2O+(tilde X2B1). Our data nicely approach those measured and computed previously. The long range parts reproduce quite well the diatomic potentials. In whole, a good agreement is found, which validates our 3D-PES.

Gannouni, M. A.; Jaidane, N. E.; Halvick, P.; Stoecklin, T.; Hochlaf, M.

2014-05-01

384

Accurate global potential energy surface for the H + OH+ collision.  

PubMed

We mapped the global three-dimensional potential energy surface (3D-PES) of the water cation at the MRCI/aug-cc-pV5Z including the basis set superposition (BSSE) correction. This PES covers the molecular region and the long ranges close to the H + OH(+)(X(3)?(-)), the O + H2(+)(X(2)?g(+)), and the hydrogen exchange channels. The quality of the PES is checked after comparison to previous experimental and theoretical results of the spectroscopic constants of H2O(+)(X(2)B1) and of the diatomic fragments, the vibronic spectrum, the dissociation energy, and the barrier to linearity for H2O(+)(X(2)B1). Our data nicely approach those measured and computed previously. The long range parts reproduce quite well the diatomic potentials. In whole, a good agreement is found, which validates our 3D-PES. PMID:24832269

Gannouni, M A; Jaidane, N E; Halvick, P; Stoecklin, T; Hochlaf, M

2014-05-14

385

Foundations of modeling in cryobiology-I: concentration, Gibbs energy, and chemical potential relationships.  

PubMed

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

Anderson, Daniel M; Benson, James D; Kearsley, Anthony J

2014-12-01

386

Vibration–Translational Energy Transfer According to the Morse Potential  

Microsoft Academic Search

A quantum-mechanical analysis of molecular vibration–translational motion energy transfer is obtained using the Morse potential, a one-dimensional model, and the method of distorted waves. All wavefunctions and transition matrix elements are obtained in closed form. In the limit of high temperatures, the results are identical to the Landau–Teller expression. At low temperatures, resonances are found to result from the attractive

Samuel L. Thompson

1968-01-01

387

Electronic structure, molecular bonding and potential energy surfaces  

SciTech Connect

By virtue of the universal validity of the generalized Born-Oppenheimer separation, potential energy surfaces (PES`) represent the central conceptual as well as quantitative entities of chemical physics and provide the basis for the understanding of most physicochemical phenomena in many diverse fields. The research in this group deals with the elucidation of general properties of PES` as well as with the quantitative determination of PES` for concrete systems, in particular pertaining to reactions involving carbon, oxygen, nitrogen and hydrogen molecules.

Ruedenberg, K. [Ames Laboratory, IA (United States)

1993-12-01

388

Energy eigenvalues for an arbitrary potential well with N minima  

Microsoft Academic Search

For a general smooth one-dimensional potential well with N minima (containing N?1 barrier humps of arbitrary shape), a phase-integral quantization condition (including ? terms) is obtained, from which the energy eigenvalues can be calculated with an accuracy relative to the chosen order of the Fro¨man phase-integral approximation. The quantization equation is derived from a condition for total transmission through a

1991-01-01

389

Potential Energy as a Plucking Criterion for Liquid Cluster Simulations  

Microsoft Academic Search

We have investigated the liquid state of atomic clusters interacting through a classical pair-wise Lennard-Jones 6-12 potential, using constant energy molecular dynamics simulations. For larger clusters (N ≳ 500-600 atoms) desorption events are frequent and a cluster in the liquid state eventually always converts to a solid state. To study the cluster as it cools, one must isolate the central

Joseph D. Coppock; Benjamin T. Bomstad; David T. Huebner; Jacquelyn P. Strey; Brian G. Moore

2008-01-01

390

Potential for luminosity improvement for low-energy RHIC operation  

SciTech Connect

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.

Fedotov A. V.

2012-05-20

391

Deflections of high energy channeled charged particles by elastically bent silicon single crystals  

SciTech Connect

The channeling and deflection of positively charged pions and protons by bent single silicon crystals was investigated over the range of momenta 10-200 GeV/c, and deflection angles in the range 0-28 milliradians. The critical radius of curvature was reached at least twice in the case of 180 GeV/c, under planer channeling conditions. The results of the experiment show that bending of channeled particles can be useful in some applications in high energy physics or accelerator technology. The results show a good agreement with the theory described by Ellison and Kudo in principle if one takes into account the effects of ordinary dechanneling. A difference with Ellison concernng the efficiency of (111)-S, (111)-L channels suggests an agreement with Kudo. Positive axial bending was investigated under limited conditions. The deflections are less than for the planar bending and the efficiency becomes less also. Feeding of the channeled particles into the planes is believed to be the reason. Negative particles channeling and bending shows very poor bending efficiency; this is explained in terms of breaking in the symmetry of the channels which has maximum effect for particles with low transverse energy.

Salman, S.M.

1982-01-01

392

The potential impact of hydrogen energy use on the atmosphere  

NASA Astrophysics Data System (ADS)

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.

van Ruijven, B. J.; Lamarque, J. F.; van Vuuren, D. P.; Kram, T.; Eerens, H.

2009-04-01

393

Evaluation of Global Onshore Wind Energy Potential and Generation Costs  

SciTech Connect

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.

Zhou, Yuyu; Luckow, Patrick; Smith, Steven J.; Clarke, Leon E.

2012-06-20

394

Spontaneous dissipation of elastic energy by self-localizing thermal runaway.  

PubMed

Thermal runaway instability induced by material softening due to shear heating represents a potential mechanism for mechanical failure of viscoelastic solids. In this work we present a model based on a continuum formulation of a viscoelastic material with Arrhenius dependence of viscosity on temperature and investigate the behavior of the thermal runaway phenomenon by analytical and numerical methods. Approximate analytical descriptions of the problem reveal that onset of thermal runaway instability is controlled by only two dimensionless combinations of physical parameters. Numerical simulations of the model independently verify these analytical results and allow a quantitative examination of the complete time evolutions of the shear stress and the spatial distributions of temperature and displacement during runaway instability. Thus we find that thermal runaway processes may well develop under nonadiabatic conditions. Moreover, nonadiabaticity of the unstable runaway mode leads to continuous and extreme localization of the strain and temperature profiles in space, demonstrating that the thermal runaway process can cause shear banding. Examples of time evolutions of the spatial distribution of the shear displacement between the interior of the shear band and the essentially nondeforming material outside are presented. Finally, a simple relation between evolution of shear stress, displacement, shear-band width, and temperature rise during runaway instability is given. PMID:19905388

Braeck, S; Podladchikov, Y Y; Medvedev, S

2009-10-01

395

CO dimer: new potential energy surface and rovibrational calculations.  

PubMed

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

Dawes, Richard; Wang, Xiao-Gang; Carrington, Tucker

2013-08-15

396

On the potential energy landscape of supercooled liquids and glasses.  

PubMed

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

Rodney, D; Schrøder, T

2011-09-01

397

Market potential for optical fiber sensors in the energy sector  

NASA Astrophysics Data System (ADS)

For a long time electric power was taken as a natural unlimited resource. With globalisation the demand for energy has risen. This has brought rising prices for fossil fuels, as well as a diversification of power generation. Besides conventional fossil, nuclear plants are coming up again. Renewable energy sources are gaining importance resulting in recent boom of wind energy plants. In the past reliability and availability and an extremely long lifetime were of paramount importance. Today this has been added by cost, due to the global competition and the high fuel costs. New designs of power components have increased efficiency using lesser material. Higher efficiency causes inevitably higher stress on the materials, of which the machines are built. As a reduction of lifetime is not acceptable and maintenance costs are expected to be at a minimum, condition monitoring systems are going to being used now. This offers potentials for fibre optic sensor application.

Bosselmann, T.

2007-07-01

398

Data Network Equipment Energy Use and Savings Potential in Buildings  

SciTech Connect

Network connectivity has become nearly ubiquitous, and the energy use of the equipment required for this connectivity is growing. Network equipment consists of devices that primarily switch and route Internet Protocol (IP) packets from a source to a destination, and this category specifically excludes edge devices like PCs, servers and other sources and sinks of IP traffic. This paper presents the results of a study of network equipment energy use and includes case studies of networks in a campus, a medium commercial building, and a typical home. The total energy use of network equipment is the product of the stock of equipment in use, the power of each device, and their usage patterns. This information was gathered from market research reports, broadband market penetration studies, field metering, and interviews with network administrators and service providers. We estimate that network equipment in the USA used 18 TWh, or about 1percent of building electricity, in 2008 and that consumption is expected to grow at roughly 6percent per year to 23 TWh in 2012; world usage in 2008 was 51 TWh. This study shows that office building network switches and residential equipment are the two largest categories of energy use consuming 40percent and 30percent of the total respectively. We estimate potential energy savings for different scenarios using forecasts of equipment stock and energy use, and savings estimates range from 20percent to 50percent based on full market penetration of efficient technologies.

Lanzisera, Steven; Nordman, Bruce; Brown, Richard E.

2010-06-09

399

Spectroscopic constants and potential energy curves of yttrium carbide (YC)  

NASA Astrophysics Data System (ADS)

The potential energy curves of the low-lying electronic states of yttrium carbide (YC) and its cation are calculated at the complete active space self-consistent field and the multireference single and double excitation configuration interaction (MRSDCI) levels of theory. Fifteen low-lying electronic states of YC with different spin and spatial symmetries were identified. The X?-4 state prevails as the ground state of YC, and a low-lying excited A?4 state is found to be 1661cm-1 higher at the MRSDCI level. The computations of the authors support the assignment of the observed spectra to a B?4(? =7/2)?A?4(?=5/2) transition with a reinterpretation that the A?4 state is appreciably populated under the experimental conditions as it is less than 2000cm-1 of the X?-4 ground state, and the previously suggested ?4 ground state is reassigned to the first low-lying excited state of YC. The potential energy curves of YC + confirm a previous prediction by Seivers et al. [J. Chem. Phys. 105, 6322 (1996)] that the ground state of YC+ is formed through a second pathway at higher energies. The calculated ionization energy of YC is 6.00eV, while the adiabatic electron affinity is 0.95eV at the MRSDCI level. The computed ionization energy of YC and dissociation energy of YC+ confirm the revised experimental estimates provided by Seivers et al. although direct experimental measurements yielded results with greater errors due to uncertainty in collisional cross sections for YC+ formation.

Suo, Bingbing; Balasubramanian, Krishnan

2007-06-01

400

Onshore wind energy potential over Iberia: present and future projections  

NASA Astrophysics Data System (ADS)

Onshore grid-connected wind power generation has been explored for more than three decades in the Iberian Peninsula. Further, increasing attention has been devoted to renewable energy sources in a climate change context. While advantages of wind energy are widely recognized, its distribution is not spatially homogeneous and not uniform throughout the year. Hence, understanding these spatial-temporal distributions is critical in power system planning. The present study aims at assessing the potential power output estimated from 10 m wind components simulated by a regional climate model (CCLM), driven by ERA40 reanalysis. Datasets are available on a grid with a high spatial resolution (approximately 20 km) and over a 40-yr period (1961-2000). Furthermore, several target sites, located in areas with high installed wind generation capacity, are selected for local-to-regional scale assessments. The results show that potential wind power is higher over northern Iberia, mostly in Cantabria and Galicia, while Andalucía and Cataluña record the lowest values. With respect to the intra-annual variability, summer is by far the season with the lowest potential energy outputs. Furthermore, the inter-annual variability reveals an overall downward long-term trend over the 40-yr period, particularly in the winter time series. A CCLM transient experiment, forced by the SRES A1B emission scenario, is also discussed for a future period (2041-2070), after a model validation/calibration process (bias corrections). Significant changes in the wind power potential are projected for the future throughout Iberia, but their magnitude largely depends on the locations. This work was partially supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE (Programa Operacional Factores de Competitividade) and by national funds through FCT (Fundação para a Ciência e a Tecnologia, Portugal) under project STORMEx FCOMP-01-0124-FEDER- 019524 (PTDC/AAC-CLI/121339/2010).

Rochinha, Carlos A.; Santos, João A.; Liberato, Margarida L. R.; Pinto, Joaquim G.

2014-05-01

401

Assessment of Tidal Stream Energy Potential for the United States  

NASA Astrophysics Data System (ADS)

Tidal streams are high velocity sea currents created by periodic horizontal movement of the tides, often magnified by local topographical features such as headlands, inlets to inland lagoons, and straits. Tidal stream energy extraction is derived from the kinetic energy of the moving flow; analogous to the way a wind turbine operates in air, and as such differs from tidal barrages, which relies on providing a head of water for energy extraction. With the constantly increasing effort in promoting alternative energy, tidal streams have become promising energy sources due to their continuous, predictable and concentrated characteristics. However, the present lack of a full spatial-temporal assessment of tidal currents for the U.S. coastline down to the scale of individual devices is a barrier to the comprehensive development of tidal current energy technology. A methodology for creating a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal energy conversion technology has been developed. The tidal flows are simulated using the Regional Ocean Modeling System (ROMS). The model is calibrated and validated using observations and tidal predictions. The calibration includes adjustments to model parameters such as bottom friction coefficient, changed land/water masks, or increased grid resolutions. A systematic validation process has been developed after defining various parameters to quantify the validation results. In order to determine the total tidal stream power resource, a common method frequently proposed is to estimate it as a fraction of the total kinetic energy flux passing through a vertical section; however, this now has been shown to generally underestimate the total available resource. The total tidal energy flux includes not just the kinetic energy but also the energy flux due to the work done by the pressure force associated with the tidal motion on the water column as well, which is frequently an order of magnitude larger. The numerical model provides the time series on a sufficiently high enough spatial resolution to utilize both the currents and mean water level (MWL) to compute the total energy flux entering estuary. The time variation of the available power for a few different estuaries will be evaluated and compared to estimates based on constant flow properties.

Haas, K. A.; Defne, Z.; Jiang, L.; Fritz, H. M.

2010-12-01

402

The alpha/beta interfaces of alpha(1)beta(1), alpha(3)beta(3), and F1: domain motions and elastic energy stored during gamma rotation.  

PubMed

ATP synthase (F(o)F(1)) consists of F(1) (ATP-driven motor) and F(o) (H(+)-driven motor). F(1) is a complex of alpha(3)beta(3)gammadeltaepsilon subunits, and gamma is the rotating cam in alpha(3)beta(3). Thermophilic F(1) (TF(1)) is exceptional in that it can be crystallized as a beta monomer and an alpha(3)beta(3) oligomer, and it is sufficiently stable to allow alphabeta refolding and reassembly of hybrid complexes containing 1, 2, and 3 modified alpha or beta. The nucleotide-dependent open-close conversion of conformation is an inherent property of an isolated beta and energy and signals are transferred through alpha/beta interfaces. The catalytic and noncatalytic interfaces of both mitochondrial F(1) (MF(1)) and TF(1) were analyzed by an atom search within the limits of 0.40 nm across the alphabeta interfaces. Seven (plus thermophilic loop in TF(1)) contact areas are located at both the catalytic and noncatalytic interfaces on the open beta form. The number of contact areas on closed beta increased to 11 and 9, respectively, in the catalytic and noncatalytic interfaces. The interfaces in the barrel domain are immobile. The torsional elastic strain applied through the mobile areas is concentrated in hinge residues and the P-loop in beta. The notion of elastic energy in F(o)F(1) has been revised. X-ray crystallography of F(1) is a static snap shot of one state and the elastic hypotheses are still inconsistent with the structure, dyamics, and kinetics of F(o)F(1). The domain motion and elastic energy in F(o)F(1) will be elucidated by time-resolved crystallography. PMID:15254382

Kagawa, Y; Hamamoto, T; Endo, H

2000-10-01

403

Potential environmental effects of energy conservation measures in northwest industries  

SciTech Connect

The Bonneville Power Administration (Bonneville) has identified 101 plants in the Pacific Northwest that account for 80% of the region's industrial electricity consumption. These plants offer a precise target for a conservation program. PNL determined that most of these 101 plants were represented by 11 major industries. We then reviewed 36 major conservation technologies used in these 11 industrial settings to determine their potential environmental impacts. Energy efficiency technologies designed for industrial use may result in direct or indirect environmental impacts. Effects may result from the production of the conservation measure technology, changes in the working environment due to different energy and material requirements, or changes to waste streams. Industry type, work-place conditions, worker training, and environmental conditions inside and outside the plant are all key variables that may affect environmental outcomes. To address these issues this report has three objectives: Describe potential conservation measures that Bonneville may employ in industrial programs and discuss potential primary impacts. Characterize industrial systems and processes where the measure may be employed and describe general environmental issues associated with each industry type. Review environmental permitting, licensing, and other regulatory actions required for industries and summarize the type of information available from these sources for further analysis.

Baechler, M C; Gygi, K F; Hendrickson, P L

1992-01-01

404

Potential impacts of nanotechnology on energy transmission applications and needs.  

SciTech Connect

The application of nanotechnologies to energy transmission has the potential to significantly impact both the deployed transmission technologies and the need for additional development. This could be a factor in assessing environmental impacts of right-of-way (ROW) development and use. For example, some nanotechnology applications may produce materials (e.g., cables) that are much stronger per unit volume than existing materials, enabling reduced footprints for construction and maintenance of electricity transmission lines. Other applications, such as more efficient lighting, lighter-weight materials for vehicle construction, and smaller batteries having greater storage capacities may reduce the need for long-distance transport of energy, and possibly reduce the need for extensive future ROW development and many attendant environmental impacts. This report introduces the field of nanotechnology, describes some of the ways in which processes and products developed with or incorporating nanomaterials differ from traditional processes and products, and identifies some examples of how nanotechnology may be used to reduce potential ROW impacts. Potential environmental, safety, and health impacts are also discussed.

Elcock, D.; Environmental Science Division

2007-11-30

405

Theoretical studies of potential energy surfaces and computational methods  

SciTech Connect

This project involves the development, implementation, and application of theoretical methods for the calculation and characterization of potential energy surfaces involving molecular species that occur in hydrocarbon combustion. These potential energy surfaces require an accurate and balanced treatment of reactants, intermediates, and products. This difficult challenge is met with general multiconfiguration self-consistent-field (MCSCF) and multireference single- and double-excitation configuration interaction (MRSDCI) methods. In contrast to the more common single-reference electronic structure methods, this approach is capable of describing accurately molecular systems that are highly distorted away from their equilibrium geometries, including reactant, fragment, and transition-state geometries, and of describing regions of the potential surface that are associated with electronic wave functions of widely varying nature. The MCSCF reference wave functions are designed to be sufficiently flexible to describe qualitatively the changes in the electronic structure over the broad range of geometries of interest. The necessary mixing of ionic, covalent, and Rydberg contributions, along with the appropriate treatment of the different electron-spin components (e.g. closed shell, high-spin open-shell, low-spin open shell, radical, diradical, etc.) of the wave functions, are treated correctly at this level. Further treatment of electron correlation effects is included using large scale multireference CI wave functions, particularly including the single and double excitations relative to the MCSCF reference space. This leads to the most flexible and accurate large-scale MRSDCI wave functions that have been used to date in global PES studies.

Shepard, R. [Argonne National Laboratory, IL (United States)

1993-12-01

406

Gravitational potential energy of the earth - A spherical harmonic approach  

NASA Technical Reports Server (NTRS)

A spherical harmonic equation for the gravitational potential energy of the earth is derived for an arbitrary density distribution by conceptually bringing in mass-elements from infinity and building up the earth shell upon spherical shell. The zeroth degree term in the spherical harmonic expansion agrees with the usual expression for the energy of a radial density distribution. The second degree terms give a maximum nonhydrostatic energy in the crust and mantle of -2.77 x 10 to the 29th ergs, an order of magnitude below McKenzie's (1966) estimate. McKenzie's result stems from mathematical error. Our figure is almost identical with Kaula's (1963) estimate of the minimum shear strain energy in the mantle, a not unexpected result on the basis of the virial theorem. If the earth is assumed to be a homogeneous viscous oblate spheroid relaxing to an equilibrium shape, then a lower limit to the mantle viscosity of 1.3 x 10 to the 20th P is found by assuming that the total geothermal flux is due to viscous dissipation of energy. This number is almost six orders of magnitude below MacDonald's (1966) estimate of the viscosity and removes his objection to convection. If the nonequilibrium figure is dynamically maintained by the earth acting as a heat engine at 1% efficiency, then the viscosity is 10 to the 22nd P, a number preferred by Cathles (1975) and Peltier and Andrew (1976) as the viscosity of the mantle.

Rubincam, D. P.

1979-01-01

407

Intermolecular potential energy surface and thermophysical properties of ethylene oxide.  

PubMed

A six-dimensional potential energy hypersurface (PES) for two interacting rigid ethylene oxide (C2H4O) molecules was determined from high-level quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the MP2 and CCSD(T) levels of theory was utilized to determine interaction energies for 10178 configurations of two molecules. An analytical site-site potential function with 19 sites per ethylene oxide molecule was fitted to the interaction energies and fine tuned to agree with data for the second acoustic virial coefficient from accurate speed of sound measurements. The PES was validated by computing the second virial coefficient, shear viscosity, and thermal conductivity. The values of these properties are substantiated by the best experimental data as they tend to fall within the uncertainty intervals and also obey the experimental temperature functions, except for viscosity, where experimental data are insufficient. Due to the lack of reliable data, especially for the transport properties, our calculated values are currently the most accurate estimates for these properties of ethylene oxide. PMID:25362314

Crusius, Johann-Philipp; Hellmann, Robert; Hassel, Egon; Bich, Eckard

2014-10-28

408

Potential for energy conservation in the cement industry  

SciTech Connect

This report assesses the potential for energy conservation in the cement industry. Energy consumption per ton of cement decreased 20% between 1972 and 1982. During this same period, the cement industry became heavily dependent on coal and coke as its primary fuel source. Although the energy consumed per ton of cement has declined markedly in the past ten years, the industry still uses more than three and a half times the fuel that is theoretically required to produce a ton of clinker. Improving kiln thermal efficiency offers the greatest opportunity for saving fuel. Improving the efficiency of finish grinding offers the greatest potential for reducing electricity use. Technologies are currently available to the cement industry to reduce its average fuel consumption per ton by product by as much as 40% and its electricity consumption per ton by about 10%. The major impediment to adopting these technologies is the cement industry's lack of capital as a result of low or no profits in recent years.

Garrett-Price, B.A.

1985-02-01

409

Intermolecular potential energy surface and thermophysical properties of ethylene oxide  

SciTech Connect

A six-dimensional potential energy hypersurface (PES) for two interacting rigid ethylene oxide (C{sub 2}H{sub 4}O) molecules was determined from high-level quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the MP2 and CCSD(T) levels of theory was utilized to determine interaction energies for 10178 configurations of two molecules. An analytical site-site potential function with 19 sites per ethylene oxide molecule was fitted to the interaction energies and fine tuned to agree with data for the second acoustic virial coefficient from accurate speed of sound measurements. The PES was validated by computing the second virial coefficient, shear viscosity, and thermal conductivity. The values of these properties are substantiated by the best experimental data as they tend to fall within the uncertainty intervals and also obey the experimental temperature functions, except for viscosity, where experimental data are insufficient. Due to the lack of reliable data, especially for the transport properties, our calculated values are currently the most accurate estimates for these properties of ethylene oxide.

Crusius, Johann-Philipp, E-mail: johann-philipp.crusius@uni-rostock.de; Hassel, Egon [Lehrstuhl für Technische Thermodynamik, Universität Rostock, 18059 Rostock (Germany); Hellmann, Robert; Bich, Eckard [Institut für Chemie, Universität Rostock, 18059 Rostock (Germany)

2014-10-28

410

Intermolecular potential energy surface and thermophysical properties of ethylene oxide  

NASA Astrophysics Data System (ADS)

A six-dimensional potential energy hypersurface (PES) for two interacting rigid ethylene oxide (C2H4O) molecules was determined from high-level quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the MP2 and CCSD(T) levels of theory was utilized to determine interaction energies for 10178 configurations of two molecules. An analytical site-site potential function with 19 sites per ethylene oxide molecule was fitted to the interaction energies and fine tuned to agree with data for the second acoustic virial coefficient from accurate speed of sound measurements. The PES was validated by computing the second virial coefficient, shear viscosity, and thermal conductivity. The values of these properties are substantiated by the best experimental data as they tend to fall within the uncertainty intervals and also obey the experimental temperature functions, except for viscosity, where experimental data are insufficient. Due to the lack of reliable data, especially for the transport properties, our calculated values are currently the most accurate estimates for these properties of ethylene oxide.

Crusius, Johann-Philipp; Hellmann, Robert; Hassel, Egon; Bich, Eckard

2014-10-01

411

Tunnel catch from potential wells and energy detection  

E-print Network

We consider the one-dimensional Schr\\"{o}dinger operator in the semiclassical regime assuming that its double-well potential is the sum of a finite "physically given" well and a square shape probing well whose width or depth can be varied (tuned). We study the dynamics of initial state localized in the physical well. It is shown that if the probing well is not too close to the physical one and if its parameters are specially tuned, then the {\\it tunnel catch effect} appears, i.e. the initial state starts tunneling oscillations between the physical and probing wells. The asymptotic formula for the probability of finding the state in the probing well is obtained. We show that the observation of the tunnel catch effect can be used to determine the energy level of the initial state, and we obtain the corresponding asymptotic formula for the initial state energy. We also calculate the leading term of the tunneling splitting of energy levels in this double well potential.

M. V. Karasev; E. V. Vybornyi

2014-11-17

412

Model-independent, multimodality deformable image registration by local matching of anatomical features and minimization of elastic energy.  

PubMed

With respect to the demands of adaptive and 4D-radiotherapy applications, an algorithm is proposed for a fully automatic, multimodality deformable registration that follows the concept of translational relocation of regularly distributed image subvolumes governed by local anatomical features. Thereby, the problem of global deformable registration is broken down to multiple independent local registration steps which allows for straightforward parallelization of the algorithm. In a subsequent step, possible local misregistrations are corrected for by minimization of the elastic energy of the displacement field under consideration of image information. The final displacement field results from interpolation of the subvolume shift vectors. The algorithm can employ as a similarity measure both the correlation coefficient and mutual information. The latter allows the application to intermodality deformable registration problems. The typical calculation time on a modern multiprocessor PC is well below 1 min, which facilitates almost-interactive, "online" usage. CT-to-MRI and CT-to-cone-beam-CT registrations of head-and-neck data sets are presented, as well as inhale-to-exhale registrations of lung CT data sets. For quantitative evaluation of registration accuracy, a virtual thorax phantom was developed; additionally, a landmark-based evaluation on four lung respiratory-correlated CT data sets was performed. This consistently resulted in average registration residuals on the order of the voxel size or less (3D-residuals approximately 1-2 mm). Summarizing, the presented algorithm allows an accurate multimodality deformable registration with calculation times well below 1 min, and thus bears promise as a versatile basic tool in adaptive and 4D-radiotherapy applications. PMID:18404923

Söhn, Matthias; Birkner, Mattias; Chi, Yuwei; Wang, Jian; Di, Yan; Berger, Bernhard; Alber, Markus

2008-03-01

413

Assessment of market potential of compressed air energy storage systems  

NASA Astrophysics Data System (ADS)

This report describes an assessment of potential roles that EPRI might take to facilitate the commercial acceptance of compressed air energy storage (CAES) systems. The assessment is based on (1) detailed analyses of the market potential of utility storage technologies, (2) interviews with representatives of key participants in the CAES market, and (3) a decision analysis synthesizing much of the information about market and technology status. The results indicate a large potential market for CAES systems if the overall business environment for utilities improves. In addition, it appears that EPRI can have a valuable incremental impact in ensuring that utilities realize the potential of CAES by (1) continuing an aggressive information dissemination and technology transfer program, (2) working to ensure the success of the first United States CAES installation at Soyland Power Cooperative, (3) developing planning methods to allow utilities to evaluate CAES and other storage options more effectively and more realistically, and (4) supporting R and D to resolve residual uncertainties in first-generation CAES cost and performance characteristics. Previously announced in STAR as N83-25121

Boyd, D. W.; Buckley, O. E.; Clark, C. E., Jr.

1983-12-01

414

Elastic scattering of hadrons  

NASA Astrophysics Data System (ADS)

Colliding high-energy hadrons either produce new particles or scatter elastically with their quantum numbers conserved and no other particles produced. We consider the latter case here. Although inelastic processes dominate at high energies, elastic scattering contributes considerably (18-25%) to the total cross section. Its share first decreases and then increases at higher energies. Small-angle scattering prevails at all energies. Some characteristic features can be seen that provide information on the geometrical structure of the colliding particles and the relevant dynamical mechanisms. The steep Gaussian peak at small angles is followed by the exponential (Orear) regime with some shoulders and dips, and then by a power-law decrease. Results from various theoretical approaches are compared with experimental data. Phenomenological models claiming to describe this process are reviewed. The unitarity condition predicts an exponential fall for the differential cross section with an additional substructure to occur exactly between the low momentum transfer diffraction cone and a power-law, hard parton scattering regime under high momentum transfer. Data on the interference of the Coulomb and nuclear parts of amplitudes at extremely small angles provide the value of the real part of the forward scattering amplitude. The real part of the elastic scattering amplitude and the contribution of inelastic processes to the imaginary part of this amplitude (the so-called overlap function) are also discussed. Problems related to the scaling behavior of the differential cross section are considered. The power-law regime at highest momentum transfer is briefly described.

Dremin, I. M.

2013-01-01

415

Potential energy surfaces and reaction dynamics of polyatomic molecules  

SciTech Connect

A simple empirical valence bond (EVB) model approach is suggested for constructing global potential energy surfaces for reactions of polyatomic molecular systems. This approach produces smooth and continuous potential surfaces which can be directly utilized in a dynamical study. Two types of reactions are of special interest, the unimolecular dissociation and the unimolecular isomerization. For the first type, the molecular dissociation dynamics of formaldehyde on the ground electronic surface is investigated through classical trajectory calculations on EVB surfaces. The product state distributions and vector correlations obtained from this study suggest very similar behaviors seen in the experiments. The intramolecular hydrogen atom transfer in the formic acid dimer is an example of the isomerization reaction. High level ab initio quantum chemistry calculations are performed to obtain optimized equilibrium and transition state dimer geometries and also the harmonic frequencies.

Chang, Yan-Tyng.

1991-11-01

416

Assessing geothermal energy potential in upstate New York. Final report  

SciTech Connect

The potential of geothermal energy for future electric power generation in New York State is evaluated using estimates of temperatures of geothermal reservoir rocks. Bottom hole temperatures from over 2000 oil and gas wells in the region were integrated into subsurface maps of the temperatures for specific geothermal reservoirs. The Theresa/Potsdam formation provides the best potential for extraction of high volumes of geothermal fluids. The evaluation of the Theresa/Potsdam geothermal reservoir in upstate New York suggests that an area 30 miles east of Elmira, New York has the highest temperatures in the reservoir rock. The Theresa/Potsdam reservoir rock should have temperatures about 136 {degrees}C and may have as much as 450 feet of porosity in excess of 8%. Estimates of the volumes of geothermal fluids that can be extracted are provided and environmental considerations for production from a geothermal well is discussed.

Hodge, D.S. [SUNY, Buffalo, NY (United States)

1996-08-01

417

Global Expression for Representing Diatomic Potential-Energy Curves  

NASA Technical Reports Server (NTRS)

A three-parameter expression that gives an accurate fit to diatomic potential curves over the entire range of separation for charge transfers between 0 and 1. It is based on a generalization of the universal binding-energy relation of Smith et al. (1989) with a modification that describes the crossover from a partially ionic state to the neutral state at large separations. The expression is tested by comparison with first-principles calculations of the potential curves ranging from covalently bonded to ionically bonded. The expression is also used to calculate spectroscopic constants form a curve fit to the first-principles curves. A comparison is made with experimental values of the spectroscopic constants.

Ferrante, John; Schlosser, Herbert; Smith, John R.

1991-01-01

418

Elastic constants of a Laves phase compound: C15 NbCr{sub 2}  

SciTech Connect

The single-crystal elastic constants of C15 NbCr{sub 2} have been computed by using a first-principles, self-consistent, full-potential total energy method. From these single-crystal elastic constants the isotropic elastic moduli are calculated using the Voigt and Reuss averages. The calculated values are in fair agreement with the experimental values. The implications of the results are discussed with regards to Poisson`s ratio and the direction dependence of Young`s modulus.

Ormeci, A. [Koc Univ., Istanbul (Turkey)]|[Los Alamos National Lab., NM (United States); Chu, F.; Wills, J.M.; Chen, S.P.; Albers, R.C.; Thoma, D.J.; Mitchell, T.E. [Los Alamos National Lab., NM (United States)

1997-04-01

419

Observation of adsorbate-induced surface states by elastic electron tunneling spectroscopy  

NASA Technical Reports Server (NTRS)

Electronic structure induced by adsorbates at the interface of Al/AlOx/Au tunnel junctions has been observed by elastic electron tunneling spectroscopy. Strong structures appearing in the tunneling spectra above approximately 1 eV after exposure to I, Hg, Bi, and organohalides, have been interpreted in terms of adsorbate-induced surface states. The spectroscopic capabilities of elastic electron tunneling spectroscopy may be useful in the area of chemical detection. In the broader sense, the observation of adsorbate-induced unoccupied electronic states below the vacuum energy, makes elastic electron tunneling spectroscopy a potentially useful technique for the study of surfaces.

Leduc, H. G.; Lambe, J.; Thakoor, A. P.; Khanna, S. K.

1985-01-01

420

The Lattice Dynamics and The Elastic Behaviour of fcc and bcc Ba  

NASA Astrophysics Data System (ADS)

The two-body pairwise E.G.E.P. (Extended Generalized Exponantial Potential) type Morse potential and volume dependent energy are assumed to represent the total energy of the Ba crystal. The parametrized potential is used to calculate the second- and third-order elastic constants Cij and Cijk, pressure derivatives of bulk moduli and Grüneisen parameter g . The phonon frequencies are also computed and plotted. The obtained results are compared with available experimental data and, in general, the agreement is good.

Çýftçý, Yasemýn Öztekýn; Çolakoðlu, Kemal

2001-07-01

421

Energy aspects and potential energy savings of the new DASI process for milk sterilization  

SciTech Connect

An experimental study was conducted to determine the difference in total processing energy required by the DASI ultra-high temperature (UHT) system and a conventional high temperature short time (HTST) fluid milk system. Data available in the literature were used to develop an energy use profile for the current US fluid milk system from processor to consumer. The energy data measured and the profile developed were used to estimate the potential energy savings resulting from the introduction of sterile milk in the US fluid milk market. Savings of energy resulting from the introduction of sterile milk were estimated to be 12 million barrels of oil annually.

Frey, B.C. (Univ. of Maryland, College Park); Stewart, L.E.; Chandarana, D.; Wolfson, R.P.

1981-01-01

422

Ultracold collisions between two light indistinguishable diatomic molecules: Elastic and rotational energy transfer in HD+HD  

NASA Astrophysics Data System (ADS)

A close coupling quantum-mechanical calculation is performed for rotational energy transfer in a HD+HD collision at very low energy, down to the ultracold temperatures: T˜10-8 K. A global six-dimensional H2-H2 potential-energy surface is adopted from a previous work [Boothroyd , J. Chem. Phys.JCPSA60021-960610.1063/1.1405008 116, 666 (2002)]. State-resolved integral cross sections ?ij?i'j'(?kin) of different quantum-mechanical rotational transitions ij?i'j' in the HD molecules and corresponding state-resolved thermal rate coefficients kij?i'j'(T) have been computed. Additionally, for comparison, H2+H2 calculations for a few selected rotational transitions have also been performed. The hydrogen and deuterated hydrogen molecules are treated as rigid rotors in this work. A pronounced isotope effect is identified in the cross sections of these collisions at low and ultracold temperatures.

Sultanov, Renat A.; Guster, Dennis; Adhikari, S. K.

2012-05-01

423

Isotopic dependence of fusion enhancement of various heavy ion systems using energy dependent Woods-Saxon potential  

NASA Astrophysics Data System (ADS)

In the present work, the fusion of symmetric and asymmetric projectile-target combinations are deeply analyzed within the framework of energy dependent Woods-Saxon potential model (EDWSP model) in conjunction with one dimensional Wong formula and the coupled channel code CCFULL. The neutron transfer channels and the inelastic surface excitations of collision partners are dominating mode of couplings and the coupling of relative motion of colliding nuclei to such relevant internal degrees of freedom produces a significant fusion enhancement at sub-barrier energies. It is quite interesting that the effects of dominant intrinsic degrees of freedom such as multi-phonon vibrational states, neutron transfer channels and proton transfer channels can be simulated by introducing the energy dependence in the nucleus-nucleus potential (EDWSP model). In the EDWSP model calculations, a wide range of diffuseness parameter ranging from a = 0.85 fm to a = 0.97 fm, which is much larger than a value (a = 0.65 fm) extracted from the elastic scattering data, is needed to reproduce sub-barrier fusion data. However, such diffuseness anomaly, which might be an artifact of some dynamical effects, has been resolved by trajectory fluctuation dissipation (TFD) model wherein the resulting nucleus-nucleus potential possesses normal diffuseness parameter.

Gautam, Manjeet Singh

2015-01-01

424

Nuclear binding energy and symmetry energy of nuclear matter with modern nucleon-nucleon potentials  

SciTech Connect

Research Highlights: > The nuclear matter is studied within the Brueckner-Hartree-Fock (BHF) approach employing the most recent accurate nucleon-nucleon potentials. > The results come out by approximating the single particle self-consistent potential with a parabolic form. > We discuss the current status of the Coester line, i.e., density and energy of the various saturation points being strongly linearly correlated. > The nuclear symmetry energy is calculated as the difference between the binding energy of pure neutron matter and that of symmetric nuclear matter. - Abstract: The binding energy of nuclear matter at zero temperature in the Brueckner-Hartree-Fock approximation with modern nucleon-nucleon potentials is studied. Both the standard and continuous choices of single particle energies are used. These modern nucleon-nucleon potentials fit the deuteron properties and are phase shifts equivalent. Comparison with other calculations is made. In addition we present results for the symmetry energy obtained with different potentials, which is of great importance in astrophysical calculation.

Hassaneen, Kh.S.A., E-mail: khs_94@yahoo.com [Physics Department, Faculty of Science, Sohag University, Sohag (Egypt); Abo-Elsebaa, H.M.; Sultan, E.A. [Physics Department, Faculty of Science, Sohag University, Sohag (Egypt); Mansour, H.M.M. [Physics Department, Faculty of Science, Cairo University, Giza (Egypt)

2011-03-15

425

Rotational Energy Transfer of N2 Gas Determined Using a New Ab Initio Potential Energy Surface  

NASA Technical Reports Server (NTRS)

Rotational energy transfer between two N2 molecules is a fundamental process of some importance. Exchange is expected to play a role, but its importance is somewhat uncertain. Rotational energy transfer cross sections of N2 also have applications in many other fields including modeling of aerodynamic flows, laser operations, and linewidth analysis in nonintrusive laser diagnostics. A number of N2-N2 rigid rotor potential energy surface (PES) has been reported in the literature.

Huo, Winifred M.; Stallcop, James R.; Partridge, Harry; Langhoff, Stephen R. (Technical Monitor)

1997-01-01

426

Collision matrix elements near a pseudocrossing of potential energy curves.  

NASA Technical Reports Server (NTRS)

The cross sections of certain inelastic atomic collision processes can be determined from the matrix elements of the collision operator, d/dR, where R is the separation of the colliding atoms. At one extreme, the matrix element may pass through zero near a pseudocrossing of potential energy curves, while at the other extreme, it may pass through a maximum. The resulting cross sections are entirely different in magnitude and in energy dependence. An attempt is made to predict the qualitative behavior of the collision matrix elements with variations in R from an analysis of the Born-Oppenheimer adiabatic Hamiltonian. The modifications caused by a second pseudocrossing with a third adiabatic state are studied.

Oppenheimer, M.

1972-01-01

427

Elastic response of shocked aluminum single crystals: a continuum analysis of molecular dynamics simulations  

NASA Astrophysics Data System (ADS)

Molecular dynamics (MD) simulations were used to examine elastic shock wave propagation in aluminum single crystals along [100], [110] and [111] directions using four different embedded-atom method potentials. Continuum variables extracted from MD results show that stresses, densities, and temperatures for [100] shock propagation are significantly different for the various potentials, while the results for [110] and [111] propagation are similar for three of the four potentials. Overall, the recent potential by Winey, Kubota and Gupta [MSMSE 17, 055004 (2009)] provides the best agreement with nonlinear elastic calculations that include elastic constants up to fourth order. Our MD-continuum approach provides a key step in establishing the applicability of classical MD potentials for dynamic compression. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Zimmerman, J. A.; Winey, J. M.; Gupta, Y. M.

2011-06-01

428

High order elastic terms, boojums and general paradigm of the elastic interaction between colloidal particles in the nematic liquid crystals  

E-print Network

Theoretical description of the elastic interaction between colloidal particles in NLC with incorporation of the higher order elastic terms beyond the limit of dipole and qudrupole interactions is proposed. The expression for the elastic interaction potential between axially symmetric colloidal particles, taking into account of the high order elastic terms, is obtained. The general paradigm of the elastic interaction between colloidal particles in NLC is proposed so that every particle with strong anchoring and radius $a$ has three zones surrounding itself. The first zone for $aelastic terms are essential nere (from 10% to 60% of the total deformation). The third zone is the zone of the main multipole moment, where higher order terms make a contribution of less than 10%. This zone extends to distances $r\\gtrapprox 4a=2D$. The case of spherical particles with planar anchoring conditions and boojums at the poles is considered as an example. It is found that boojums can be described analitically via multipole expansion with accuracy up to $1/r^{7}$ and the whole spherical particle can be effectively considered as the multipole of the order 6 with multipolarity equal $2^{6}=64$. The correspondent elastic interaction with higher order elastic terms gives the angle $\\theta_{min}=34.5^{\\circ}$ of minimum energy between two contact beads which is close to the experimental value of $\\theta_{min}=30^{\\circ}$.

S. B. Chernyshuk

2013-05-11

429

Complex potential and bottomonium suppression at LHC energy  

NASA Astrophysics Data System (ADS)

We have studied the thermal suppression of the bottomonium states in relativistic heavy-ion collision at LHC energies as function of centrality, rapidity, transverse momentum. First, we address the effects of the nonperturbative confining force and the momentum anisotropy together on heavy quark potential at finite temperature, which are resolved by correcting both the perturbative and nonperturbative terms of the potential at T = 0 in a weakly-anisotropic medium, not its perturbative term alone as usually done in the literature. Second, we model the expansion of medium by the Bjorken hydrodynamics in the presence of both shear and bulk viscosity, followed by an additional pre-equilibrium anisotropic evolution. Finally, we couple them together to quantify the yields of bottomonium production in nucleus-nucleus collisions at LHC energies and found a better agreement with the CMS data. Our estimate of the inclusive ?(1S) production indirectly constrains both the uncertainties in isotropization time and the shear-to-entropy density ratio and favors the values as 0.3 fm/c and 0.3 (perturbative result), respectively.

Kakade, Uttam; Patra, Binoy Krishna; Thakur, Lata

2015-03-01

430

An Ab Initio Based Potential Energy Surface for Water  

NASA Technical Reports Server (NTRS)

We report a new determination of the water potential energy surface. A high quality ab initio potential energy surface (PES) and dipole moment function of water have been computed. This PES is empirically adjusted to improve the agreement between the computed line positions and those from the HITRAN 92 data base. The adjustment is small, nonetheless including an estimate of core (oxygen 1s) electron correlation greatly improves the agreement with experiment. Of the 27,245 assigned transitions in the HITRAN 92 data base for H2(O-16), the overall root mean square (rms) deviation between the computed and observed line positions is 0.125/cm. However the deviations do not correspond to a normal distribution: 69% of the lines have errors less than 0.05/cm. Overall, the agreement between the line intensities computed in the present work and those contained in the data base is quite good, however there are a significant number of line strengths which differ greatly.

Partridge, Harry; Schwenke, David W.; Langhoff, Stephen R. (Technical Monitor)

1996-01-01

431

Price elasticity for gasoline revisited  

SciTech Connect

A reexamination of the 1974 findngs of Houthakker, Verleger, and Sheehan confirms that gasoline prices can promote energy conservation and that demand responses devlop over time. The empirical evidence is consistent with other earlier studies. The responsiveness observed during the 1962 to 73 sample period probably understates present economic elasticity because gasoline prices now require a larger share of disposable income, making a -1.5 price elasticity more realistic. 8 references, 1 table. (DCK)

Pelaez, R.F.

1981-10-01

432

Energy Conservation Simplified  

ERIC Educational Resources Information Center

The standard formulation of energy conservation involves the subsidiary ideas of kinetic energy ("KE"), work ("W"), thermal energy, internal energy, and a half-dozen different kinds of potential energy ("PE"): elastic, chemical, nuclear, gravitational, and so forth. These quantities came to be recognized during the centuries over which the…

Hecht, Eugene

2008-01-01

433

Steam systems in industry: Energy use and energy efficiency improvement potentials  

SciTech Connect

Steam systems are a part of almost every major industrial process today. Thirty-seven percent of the fossil fuel burned in US industry is burned to produce steam. In this paper we will establish baseline energy consumption for steam systems. Based on a detailed analysis of boiler energy use we estimate current energy use in boilers in U.S. industry at 6.1 Quads (6.4 EJ), emitting almost 66 MtC in CO{sub 2} emissions. We will discuss fuels used and boiler size distribution. We also describe potential savings measures, and estimate the economic energy savings potential in U.S. industry (i.e. having payback period of 3 years or less). We estimate the nationwide economic potential, based on the evaluation of 16 individual measures in steam generation and distribution. The analysis excludes the efficient use of steam and increased heat recovery. Based on the analysis we estimate the economic potential at 18-20% of total boiler energy use, resulting in energy savings approximately 1120-1190 TBtu ( 1180-1260 PJ). This results in a reduction of CO{sub 2} emissions equivalent to 12-13 MtC.

Einstein, Dan; Worrell, Ernst; Khrushch, Marta

2001-07-22

434

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

E-print Network

, concrete, and composite brittle material samples, and it predicts macroscopic failure at stress levels are one to two orders of magnitude above the values estimated from stress­strain relations in quasi materials, damaged rocks, brittle deformation. 1. Introduction Nonlinear elastic deformation of damaged

Lyakhovsky, Vladimir

435

Crack growth in bonded elastic half planes  

NASA Technical Reports Server (NTRS)

Two solutions were developed for the two dimensional problem of bonded linearly elastic half-planes. For each solution, numerical results are presented for the stress intensity factors, strain energy release rate, stresses, and displacements. The behavior predicted by the studies was investigated experimentally using polymers for the material pairs. Close agreement was found for the critical stress intensity factor at fracture for the perpendicular crack near the interface. Fracture along the interface proved to be inconclusive due to difficulties in obtaining a brittle bond. Some interesting and predictable behavior regarding the potential for the crack to cross the interface was observed and is discussed.

Goree, J. G.

1975-01-01

436

Potential contribution of wind energy to climate change mitigation  

NASA Astrophysics Data System (ADS)

It is still possible to limit greenhouse gas emissions to avoid the 2 °C warming threshold for dangerous climate change. Here we explore the potential role of expanded wind energy deployment in climate change mitigation efforts. At present, most turbines are located in extra-tropical Asia, Europe and North America, where climate projections indicate continuity of the abundant wind resource during this century. Scenarios from international agencies indicate that this virtually carbon-free source could supply 10-31% of electricity worldwide by 2050 (refs , ). Using these projections within Intergovernmental Panel on Climate Change Representative Concentration Pathway (RCP) climate forcing scenarios, we show that dependent on the precise RCP followed, pursuing a moderate wind energy deployment plan by 2050 delays crossing the 2 °C warming threshold by 1-6 years. Using more aggressive wind turbine deployment strategies delays 2 °C warming by 3-10 years, or in the case of RCP4.5 avoids passing this threshold altogether. To maximize these climate benefits, deployment of non-fossil electricity generation must be coupled with reduced energy use.

Barthelmie, R. J.; Pryor, S. C.

2014-08-01

437

Semimicroscopic calculations of elastic, inelastic, and total neutron scattering by 239Pu in the energy range 10 keV <=En<=10 MeV  

NASA Astrophysics Data System (ADS)

We investigate the capabilities of a semimicroscopic optical model potential involving fewer adjustable parameters than phenomenological models and test the sensitivity of this potential to various rotational band assumptions. Our analysis of the model capabilities is performed using experimental elastic, inelastic, and total cross sections as well as experimental neutron strength functions. We compare our calculations to these experiments and to the predictions of a phenomenological model. Our sensitivity study is performed for the first three rotational bands of 239Pu. The two main ingredients of our calculations are the microscopic optical-model potential of Jeukenne, Lejeune, and Mahaux and nuclear densities from Hartree-Fock-Bogoliubov calculations using the density-dependent force D1.

Lagrange, Ch.; Madland, D. G.; Girod, M.

1986-05-01

438

Potential of renewable energy sources and its applications in Yakushima Island  

Microsoft Academic Search

A study was carried out to see if the potential of renewable energy sources other than hy droelectric power, such as wind, photovoltaic, solar thermal, biomass and waste energy sources, can meet the current energy consumption in Yakushima. The current electricity consumption can be covered by wind and photovoltaic energy sources. The total potential of wind and photovoltaic energy sources

Yoshimitsu Uemura; Takami Kai; Rintarou Natori; Takeshige Takahashi; Yasuo Hatate; Masahiro Yoshida

2004-01-01

439

Exploration of the ranges of the global potential of biomass for energy  

Microsoft Academic Search

This study explores the range of future world potential of biomass for energy. The focus has been put on the factors that influence the potential biomass availability for energy purposes rather than give exact numbers. Six biomass resource categories for energy are identified: energy crops on surplus cropland, energy crops on degraded land, agricultural residues, forest residues, animal manure and

Monique Hoogwijk; Richard van den Broek; Göran Berndes; Dolf Gielen; Wim Turkenburg

2003-01-01

440

Microscopic optical model potentials for p-nucleus scattering at intermediate energies  

NASA Astrophysics Data System (ADS)

A comparative study of the microscopic optical potentials viz., semimicroscopic with extended Jeukenne-Lejeune-Mahaux interaction and microscopic Brueckner theory using Hamada-Johnston as well as Urbana V14 soft-core internucleon interactions, has been carried out. These microscopic optical potentials are compared with that of Dirac phenomenology (DP) for the polarized proton-Ca40 elastic scattering at 35 MeV and 200 MeV. These potentials have different shapes for 200 MeV below 4 fm. In particular, for the real part of the central potential, only the Dirac phenomenology and the microscopic optical potential calculated with the Hamada-Johnston interaction exhibit the well known wine-bottle-bottom shape. It is found that the calculated observables (cross section, analyzing power and spin rotation function) using these potentials having different shapes, compare well with the experiment.

Hemalatha, M.; Gambhir, Y. K.; Kailas, S.; Haider, W.

2007-03-01

441

Microscopic optical model potentials for p-nucleus scattering at intermediate energies  

SciTech Connect

A comparative study of the microscopic optical potentials viz., semimicroscopic with extended Jeukenne-Lejeune-Mahaux interaction and microscopic Brueckner theory using Hamada-Johnston as well as Urbana V14 soft-core internucleon interactions, has been carried out. These microscopic optical potentials are compared with that of Dirac phenomenology (DP) for the polarized proton-{sup 40}Ca elastic scattering at 35 MeV and 200 MeV. These potentials have different shapes for 200 MeV below 4 fm. In particular, for the real part of the central potential, only the Dirac phenomenology and the microscopic optical potential calculated with the Hamada-Johnston interaction exhibit the well known wine-bottle-bottom shape. It is found that the calculated observables (cross section, analyzing power and spin rotation function) using these potentials having different shapes, compare well with the experiment.

Hemalatha, M. [Department of Physics, I.I.T.-Powai, Mumbai 400076 (India); Gambhir, Y. K. [Department of Physics, I.I.T.-Powai, Mumbai 400076 (India); Manipal Academy of Higher Education, Manipal 576119 (India); Kailas, S. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Haider, W. [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India)

2007-03-15

442

Electron-impact rotationally elastic total cross sections for H{sub 2}CO and HCOOH over a wide range of incident energy (0.01-2000 eV)  

SciTech Connect

This paper reports computational results of the total cross sections for electron impact on H{sub 2}CO and HCOOH over a wide range of electron impact energies from 0.01 eV to 2 keV. The total cross section is presented as sum of the elastic and electronic excitation cross sections for incident energies. The calculation uses two different methodologies, below the ionization threshold of the target the cross section is calculated using the UK molecular R-matrix code through the Quantemol-N software package while cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent at the transition energy ({approx}15 eV). The present results are, in general, found to be in good agreement with previous experimental and theoretical results (wherever available) and, thus, the present results can serve as a benchmark for the cross section over a wide range of energy.

Vinodkumar, Minaxi [V P and R P T P Science College, Vallabh Vidyanagar 388 120, Gujarat (India); Bhutadia, Harshad [Government Engineering College, Patan 384265, Gujarat (India); Antony, Bobby [Department of Applied Physics, Indian School of Mines, Dhanbad JH-826004 (India); Mason, Nigel [Department of Physics and Astronomy, Open University, Milton Keynes MK7 6AA (United Kingdom)

2011-11-15

443

Potential of Using Poultry Litter as a Feedstock for Energy Production Rangika Perera, Graduate Research Assistant  

E-print Network

Potential of Using Poultry Litter as a Feedstock for Energy Production Rangika Perera, Graduate .......................................................................................................................................................................... 3 2. Potential of Poultry Litter for Energy Generation ......................................................................................................................................................... 5 4. Current Markets and Demand for Poultry Litter

444

French Brittany macroalgae screening: composition and methane potential for potential alternative sources of energy and products.  

PubMed

Macroalgae are biomass resources that represent a valuable feedstock to be used entirely for human consumption or for food additives after some extractions (mainly colloids) and/or for energy production. In order to better develop the algal sector, it is important to determine the capacity of macroalgae to produce these added-values molecules for food and/or for energy industries on the basis of their biochemical characteristics. In this study, ten macroalgae obtained from French Brittany coasts (France) were selected. The global biochemical composition (proteins, lipids, carbohydrates, fibers), the presence and characteristics of added-values molecules (alginates, polyphenols) and the biochemical methane potential of these algae were determined. Regarding its biochemical composition, Palmaria palmata is interesting for food (rich in nutrients) and for anaerobic digestion (0.279 LCH4/gVS). Saccharina latissima could be used for alginate extraction (242 g/kgTS, ratio between mannuronic and guluronic acid M/G=1.4) and Sargassum muticum for polyphenol extraction (19.8 g/kgTS). PMID:23896436

Jard, G; Marfaing, H; Carrère, H; Delgenes, J P; Steyer, J P; Dumas, C

2013-09-01

445

Osmosis, colligative properties, entropy, free energy and the chemical potential  

E-print Network

A diffusive model of osmosis is presented that explains currently available experimental data. It makes predictions that distinguish it from the traditional convective flow model of osmosis, some of which have already been confirmed experimentally and others have yet to be tested. It also provides a simple kinetic explanation of Raoult's law and the colligative properties of dilute aqueous solutions. The diffusive model explains that when a water molecule jumps from low to high osmolarity at equilibrium, the free energy change is zero because the work done pressurizing the water molecule is balanced by the entropy of mixing. It also explains that equal chemical potentials are required for particle exchange equilibrium in analogy with the familiar requirement of equal temperatures at thermal equilibrium.

Peter Hugo Nelson

2014-09-13

446

Potential alternative energy technologies on the Outer Continental Shelf.  

SciTech Connect

This technical memorandum (TM) describes the technology requirements for three alternative energy technologies for which pilot and/or commercial projects on the U.S. Outer Continental Shelf (OCS) are likely to be proposed within the next five to seven years. For each of the alternative technologies--wind, wave, and ocean current--the TM first presents an overview. After each technology-specific overview, it describes the technology requirements for four development phases: site monitoring and testing, construction, operation, and decommissioning. For each phase, the report covers the following topics (where data are available): facility description, electricity generated, ocean area (surface and bottom) occupied, resource requirements, emissions and noise sources, hazardous materials stored or used, transportation requirements, and accident potential. Where appropriate, the TM distinguishes between pilot-scale (or demonstration-scale) facilities and commercial-scale facilities.

Elcock, D.; Environmental Assessment

2007-04-20

447

Relation between quark-antiquark potential and quark-antiquark free energy in hadronic matter  

E-print Network

We study the relation between the quark-antiquark potential and the quark-antiquark free energy in hadronic matter. While a temperature is over the critical temperature, the potential of a heavy quark and a heavy antiquark almost equals the free energy, otherwise the quark-antiquark potential is substantially larger than the quark-antiquark free energy. While a temperature is below the critical temperature, the quark-antiquark free energy can be taken as the quark-antiquark potential.

Zhen-Yu Shen; Xiao-Ming Xu

2014-06-19

448

Single-crystal elastic properties of (Cs,Na)AlSi2O6.H2O pollucite: A zeolite with potential use for long-term storage of Cs radioisotopes  

NASA Astrophysics Data System (ADS)

The single-crystal and aggregate elastic properties of the zeolite pollucite (Cs,Na)AlSi2O6?H2O, a potential host for Cs radionucleides in geological repositories, have been determined by Brillouin scattering spectroscopy at ambient conditions. The three nonzero individual elastic constants of cubic pollucite are: C11=105.0(1.3) GPa, C44=27.0(3) GPa, and C12=25.7(6) GPa. The Voigt-Reuss-Hill average of the aggregate bulk, shear modulus, Young's modulus and Poisson's ratio are KS=52.2(1.0) GPa, G=31.5(7) GPa, E=78.6(1.0) GPa, and ? =0.248(4), respectively. The bulk modulus of pollucite is 12.7% lower than that of the all-Na isotypic mineral analcime NaAlSi2O6?H2O whereas the shear moduli G are identical within mutual uncertainties. The higher compressibility of pollucite results from the weaker Cs-O bonds compared to Na-O bonds, suggesting strong control of the nature and configuration of the extraframework content on the behavior of the structure. The elastic properties of pollucite reported here will help in the prediction of its behavior as a geological barrier and in the modeling of the short-term and long-term safety of the Cs-repositories.

Sanchez-Valle, Carmen; Chio, Chi-Hong; Gatta, G. Diego

2010-11-01

449

First-principles computational studies of the torsional potential energy surface of the sec-butyl  

E-print Network

to investigate the torsional potential energy surface (PES) of the sec- butyl radical. All the wave function words: sec-butyl, torsional potential energy surface, density functional theory, wave function theoryFirst-principles computational studies of the torsional potential energy surface of the sec

Wang, Yan Alexander

450

Adhesion of Elastic Spheres  

NASA Astrophysics Data System (ADS)

Bradley (1932) showed that if two rigid spheres of radii R1 and R2 are placed in contact, they will adhere with a force 2? R? ? , where R is the equivalent radius R1R2/(R1 + R2) and ? ? is the surface energy or 'work of adhesion' (equal to ? 1 + ? 2 - ? 12). Subsequently Johnson et al. (1971) (JKR theory) showed by a Griffith energy argument (assuming that contact over a circle of radius a introduces a surface energy -? a2? ? ) how the Hertz equations for the contact of elastic spheres are modifed by surface energy, and showed that the force needed to separate the spheres is equal to (3/2)? R? ? , which is independent of the elastic modulus and so appears to be universally applicable and therefore to conflict with Bradley's answer. The discrepancy was explained by Tabor (1977), who identified a parameter ? equiv R1/3? ? 2/3/E* 2/3? governing the transition from the Bradley pull-off force 2? R? ? to the JKR value (3/2)? R? ? . Subsequently Muller et al. (1980) performed a complete numerical solution in terms of surface forces rather than surface energy, (combining the Lennard-Jones law of force between surfaces with the elastic equations for a half-space), and confirmed that Tabor's parameter does indeed govern the transition. The numerical solution is repeated more accurately and in greater detail, confirming the results, but showing also that the load-approach curves become S-shaped for values of ? greater than one, leading to jumps into and out of contact. The JKR equations describe the behaviour well for values of ? of 3 or more, but for low values of ? the simple Bradley equation better describes the behaviour under negative loads.

Greenwood, J. A.

1997-06-01

451

Potential of utilization of geothermal energy in Arizona  

NASA Astrophysics Data System (ADS)

Arizona is one of the fastest growing states in the United States. It is in the midst of the movement of the population of the United States from its cold regions to the warm Southwest. Being a hot, arid region, its electrical demand is nearly 50% higher in the peak hot summer months than that of the other 7 months. The major uncertainty of utilizing geothermal energy in Arizona is that very little exploration and development have occurred to date. The potential for utilizing geothermal energy in Arizona is good based on the fat thatthere are over 3000 thermal wells in Arizona out of a total of about 30,000 shallow irrigation wells that were examined. There is much young volcanic rock in Arizona. The combination of data from thermal wells, young volcanic rock, water geochemistry and other geological tools, indicate that there is a large geothermal resource throughout the southern half of the state. It is suggested that most of this resource is in the range of 500 to 1500 C, limiting its uses to direct heat utilization rather than for electric power generation.

White, D. H.; Goldstone, L. A.

1982-08-01

452

Potential for supplying solar thermal energy to industrial unit operations  

SciTech Connect

Previous studies have identified major industries deemed most appropriate for the near-term adoption of solar thermal technology to provide process heat; these studies have been based on surveys that followed standard industrial classifications. This paper presents an alternate, perhaps simpler analysis of this potential, considered in terms of the end-use of energy delivered to industrial unit operations. For example, materials, such as animal feed, can be air dried at much lower temperatures than are currently used. This situation is likely to continue while economic supplies of natural gas are readily available. However, restriction of these supplies could lead to the use of low-temperature processes, which are more easily integrated with solar thermal technology. The adoption of solar technology is also favored by other changes, such as the relative rates of increase of the costs of electricity and natural gas, and by energy conservation measures. Thus, the use of low-pressure steam to provide process heat could be replaced economically with high-temperature hot water systems, which are more compatible with solar technology. On the other hand, for certain operations such as high-temperature catalytic and distillation processes employed in petroleum refining, there is no ready alternative to presently employed fluid fuels.

May, E.K.

1980-04-01

453

Wind and Solar Energy Potential Assessment for Development of Renewables Energies Applications in Bucaramanga, Colombia  

NASA Astrophysics Data System (ADS)

Currently, the trend of micro-grids and small-scale renewable generation systems implementation in urban environments requires to have historical and detailed information about the energy potential resource in site. In Colombia, this information is limited and do not favor the design of these applications; for this reason, must be made detailed studies of the energy potential in their cities. In this paper is presented the wind and solar energy resource assessment for the city of Bucaramanga, based on the monitoring on four strategic points during the years 2010, 2011 and 2012. According to the analysis, is evidenced a significant solar resource throughout the year ascending on average to 1 734 kWh/m2, equivalent to 4.8 kWh/m2/day. Also, from a wind statistical study based on the Weibull probability distribution and Wind Power Density (WPD) was established the wind potential as Class 1 according to the scale of the Department of Energy of the United States (DOE), since the average speed is near 1.4 m/s. Due this, it is technically unfeasible the using of micro-turbines in the city, even so their potential for natural ventilation of building was analyzed. Finally, is presented a methodology to analyze solar harvesting by sectors in the city, according to the solar motion and shadowing caused by existing structures.

Ordóñez, G.; Osma, G.; Vergara, P.; Rey, J.

2014-06-01

454

Intraclass Price Elasticity & Electric Rate Design  

E-print Network

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... the elasti cities will be in the zero to 1.0 range. INTRACLASS PRICE ELASTICITY MODEL John H.